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linuxdebug/drivers/tty/serial/fsl_lpuart.c

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null pointer error
2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0+
/*
* Freescale lpuart serial port driver
*
* Copyright 2012-2014 Freescale Semiconductor, Inc.
*/
#include <linux/clk.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/dmapool.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <linux/serial_core.h>
#include <linux/slab.h>
#include <linux/tty_flip.h>
/* All registers are 8-bit width */
#define UARTBDH 0x00
#define UARTBDL 0x01
#define UARTCR1 0x02
#define UARTCR2 0x03
#define UARTSR1 0x04
#define UARTCR3 0x06
#define UARTDR 0x07
#define UARTCR4 0x0a
#define UARTCR5 0x0b
#define UARTMODEM 0x0d
#define UARTPFIFO 0x10
#define UARTCFIFO 0x11
#define UARTSFIFO 0x12
#define UARTTWFIFO 0x13
#define UARTTCFIFO 0x14
#define UARTRWFIFO 0x15
#define UARTBDH_LBKDIE 0x80
#define UARTBDH_RXEDGIE 0x40
#define UARTBDH_SBR_MASK 0x1f
#define UARTCR1_LOOPS 0x80
#define UARTCR1_RSRC 0x20
#define UARTCR1_M 0x10
#define UARTCR1_WAKE 0x08
#define UARTCR1_ILT 0x04
#define UARTCR1_PE 0x02
#define UARTCR1_PT 0x01
#define UARTCR2_TIE 0x80
#define UARTCR2_TCIE 0x40
#define UARTCR2_RIE 0x20
#define UARTCR2_ILIE 0x10
#define UARTCR2_TE 0x08
#define UARTCR2_RE 0x04
#define UARTCR2_RWU 0x02
#define UARTCR2_SBK 0x01
#define UARTSR1_TDRE 0x80
#define UARTSR1_TC 0x40
#define UARTSR1_RDRF 0x20
#define UARTSR1_IDLE 0x10
#define UARTSR1_OR 0x08
#define UARTSR1_NF 0x04
#define UARTSR1_FE 0x02
#define UARTSR1_PE 0x01
#define UARTCR3_R8 0x80
#define UARTCR3_T8 0x40
#define UARTCR3_TXDIR 0x20
#define UARTCR3_TXINV 0x10
#define UARTCR3_ORIE 0x08
#define UARTCR3_NEIE 0x04
#define UARTCR3_FEIE 0x02
#define UARTCR3_PEIE 0x01
#define UARTCR4_MAEN1 0x80
#define UARTCR4_MAEN2 0x40
#define UARTCR4_M10 0x20
#define UARTCR4_BRFA_MASK 0x1f
#define UARTCR4_BRFA_OFF 0
#define UARTCR5_TDMAS 0x80
#define UARTCR5_RDMAS 0x20
#define UARTMODEM_RXRTSE 0x08
#define UARTMODEM_TXRTSPOL 0x04
#define UARTMODEM_TXRTSE 0x02
#define UARTMODEM_TXCTSE 0x01
#define UARTPFIFO_TXFE 0x80
#define UARTPFIFO_FIFOSIZE_MASK 0x7
#define UARTPFIFO_TXSIZE_OFF 4
#define UARTPFIFO_RXFE 0x08
#define UARTPFIFO_RXSIZE_OFF 0
#define UARTCFIFO_TXFLUSH 0x80
#define UARTCFIFO_RXFLUSH 0x40
#define UARTCFIFO_RXOFE 0x04
#define UARTCFIFO_TXOFE 0x02
#define UARTCFIFO_RXUFE 0x01
#define UARTSFIFO_TXEMPT 0x80
#define UARTSFIFO_RXEMPT 0x40
#define UARTSFIFO_RXOF 0x04
#define UARTSFIFO_TXOF 0x02
#define UARTSFIFO_RXUF 0x01
/* 32-bit global registers only for i.MX7ULP/i.MX8x
* Used to reset all internal logic and registers, except the Global Register.
*/
#define UART_GLOBAL 0x8
/* 32-bit register definition */
#define UARTBAUD 0x00
#define UARTSTAT 0x04
#define UARTCTRL 0x08
#define UARTDATA 0x0C
#define UARTMATCH 0x10
#define UARTMODIR 0x14
#define UARTFIFO 0x18
#define UARTWATER 0x1c
#define UARTBAUD_MAEN1 0x80000000
#define UARTBAUD_MAEN2 0x40000000
#define UARTBAUD_M10 0x20000000
#define UARTBAUD_TDMAE 0x00800000
#define UARTBAUD_RDMAE 0x00200000
#define UARTBAUD_MATCFG 0x00400000
#define UARTBAUD_BOTHEDGE 0x00020000
#define UARTBAUD_RESYNCDIS 0x00010000
#define UARTBAUD_LBKDIE 0x00008000
#define UARTBAUD_RXEDGIE 0x00004000
#define UARTBAUD_SBNS 0x00002000
#define UARTBAUD_SBR 0x00000000
#define UARTBAUD_SBR_MASK 0x1fff
#define UARTBAUD_OSR_MASK 0x1f
#define UARTBAUD_OSR_SHIFT 24
#define UARTSTAT_LBKDIF 0x80000000
#define UARTSTAT_RXEDGIF 0x40000000
#define UARTSTAT_MSBF 0x20000000
#define UARTSTAT_RXINV 0x10000000
#define UARTSTAT_RWUID 0x08000000
#define UARTSTAT_BRK13 0x04000000
#define UARTSTAT_LBKDE 0x02000000
#define UARTSTAT_RAF 0x01000000
#define UARTSTAT_TDRE 0x00800000
#define UARTSTAT_TC 0x00400000
#define UARTSTAT_RDRF 0x00200000
#define UARTSTAT_IDLE 0x00100000
#define UARTSTAT_OR 0x00080000
#define UARTSTAT_NF 0x00040000
#define UARTSTAT_FE 0x00020000
#define UARTSTAT_PE 0x00010000
#define UARTSTAT_MA1F 0x00008000
#define UARTSTAT_M21F 0x00004000
#define UARTCTRL_R8T9 0x80000000
#define UARTCTRL_R9T8 0x40000000
#define UARTCTRL_TXDIR 0x20000000
#define UARTCTRL_TXINV 0x10000000
#define UARTCTRL_ORIE 0x08000000
#define UARTCTRL_NEIE 0x04000000
#define UARTCTRL_FEIE 0x02000000
#define UARTCTRL_PEIE 0x01000000
#define UARTCTRL_TIE 0x00800000
#define UARTCTRL_TCIE 0x00400000
#define UARTCTRL_RIE 0x00200000
#define UARTCTRL_ILIE 0x00100000
#define UARTCTRL_TE 0x00080000
#define UARTCTRL_RE 0x00040000
#define UARTCTRL_RWU 0x00020000
#define UARTCTRL_SBK 0x00010000
#define UARTCTRL_MA1IE 0x00008000
#define UARTCTRL_MA2IE 0x00004000
#define UARTCTRL_IDLECFG 0x00000100
#define UARTCTRL_LOOPS 0x00000080
#define UARTCTRL_DOZEEN 0x00000040
#define UARTCTRL_RSRC 0x00000020
#define UARTCTRL_M 0x00000010
#define UARTCTRL_WAKE 0x00000008
#define UARTCTRL_ILT 0x00000004
#define UARTCTRL_PE 0x00000002
#define UARTCTRL_PT 0x00000001
#define UARTDATA_NOISY 0x00008000
#define UARTDATA_PARITYE 0x00004000
#define UARTDATA_FRETSC 0x00002000
#define UARTDATA_RXEMPT 0x00001000
#define UARTDATA_IDLINE 0x00000800
#define UARTDATA_MASK 0x3ff
#define UARTMODIR_IREN 0x00020000
#define UARTMODIR_TXCTSSRC 0x00000020
#define UARTMODIR_TXCTSC 0x00000010
#define UARTMODIR_RXRTSE 0x00000008
#define UARTMODIR_TXRTSPOL 0x00000004
#define UARTMODIR_TXRTSE 0x00000002
#define UARTMODIR_TXCTSE 0x00000001
#define UARTFIFO_TXEMPT 0x00800000
#define UARTFIFO_RXEMPT 0x00400000
#define UARTFIFO_TXOF 0x00020000
#define UARTFIFO_RXUF 0x00010000
#define UARTFIFO_TXFLUSH 0x00008000
#define UARTFIFO_RXFLUSH 0x00004000
#define UARTFIFO_TXOFE 0x00000200
#define UARTFIFO_RXUFE 0x00000100
#define UARTFIFO_TXFE 0x00000080
#define UARTFIFO_FIFOSIZE_MASK 0x7
#define UARTFIFO_TXSIZE_OFF 4
#define UARTFIFO_RXFE 0x00000008
#define UARTFIFO_RXSIZE_OFF 0
#define UARTFIFO_DEPTH(x) (0x1 << ((x) ? ((x) + 1) : 0))
#define UARTWATER_COUNT_MASK 0xff
#define UARTWATER_TXCNT_OFF 8
#define UARTWATER_RXCNT_OFF 24
#define UARTWATER_WATER_MASK 0xff
#define UARTWATER_TXWATER_OFF 0
#define UARTWATER_RXWATER_OFF 16
#define UART_GLOBAL_RST 0x2
#define GLOBAL_RST_MIN_US 20
#define GLOBAL_RST_MAX_US 40
/* Rx DMA timeout in ms, which is used to calculate Rx ring buffer size */
#define DMA_RX_TIMEOUT (10)
#define DRIVER_NAME "fsl-lpuart"
#define DEV_NAME "ttyLP"
#define UART_NR 6
/* IMX lpuart has four extra unused regs located at the beginning */
#define IMX_REG_OFF 0x10
enum lpuart_type {
VF610_LPUART,
LS1021A_LPUART,
LS1028A_LPUART,
IMX7ULP_LPUART,
IMX8QXP_LPUART,
IMXRT1050_LPUART,
};
struct lpuart_port {
struct uart_port port;
enum lpuart_type devtype;
struct clk *ipg_clk;
struct clk *baud_clk;
unsigned int txfifo_size;
unsigned int rxfifo_size;
u8 rx_watermark;
bool lpuart_dma_tx_use;
bool lpuart_dma_rx_use;
struct dma_chan *dma_tx_chan;
struct dma_chan *dma_rx_chan;
struct dma_async_tx_descriptor *dma_tx_desc;
struct dma_async_tx_descriptor *dma_rx_desc;
dma_cookie_t dma_tx_cookie;
dma_cookie_t dma_rx_cookie;
unsigned int dma_tx_bytes;
unsigned int dma_rx_bytes;
bool dma_tx_in_progress;
unsigned int dma_rx_timeout;
struct timer_list lpuart_timer;
struct scatterlist rx_sgl, tx_sgl[2];
struct circ_buf rx_ring;
int rx_dma_rng_buf_len;
unsigned int dma_tx_nents;
wait_queue_head_t dma_wait;
bool is_cs7; /* Set to true when character size is 7 */
/* and the parity is enabled */
};
struct lpuart_soc_data {
enum lpuart_type devtype;
char iotype;
u8 reg_off;
u8 rx_watermark;
};
static const struct lpuart_soc_data vf_data = {
.devtype = VF610_LPUART,
.iotype = UPIO_MEM,
.rx_watermark = 1,
};
static const struct lpuart_soc_data ls1021a_data = {
.devtype = LS1021A_LPUART,
.iotype = UPIO_MEM32BE,
.rx_watermark = 1,
};
static const struct lpuart_soc_data ls1028a_data = {
.devtype = LS1028A_LPUART,
.iotype = UPIO_MEM32,
.rx_watermark = 0,
};
static struct lpuart_soc_data imx7ulp_data = {
.devtype = IMX7ULP_LPUART,
.iotype = UPIO_MEM32,
.reg_off = IMX_REG_OFF,
.rx_watermark = 1,
};
static struct lpuart_soc_data imx8qxp_data = {
.devtype = IMX8QXP_LPUART,
.iotype = UPIO_MEM32,
.reg_off = IMX_REG_OFF,
.rx_watermark = 1,
};
static struct lpuart_soc_data imxrt1050_data = {
.devtype = IMXRT1050_LPUART,
.iotype = UPIO_MEM32,
.reg_off = IMX_REG_OFF,
.rx_watermark = 1,
};
static const struct of_device_id lpuart_dt_ids[] = {
{ .compatible = "fsl,vf610-lpuart", .data = &vf_data, },
{ .compatible = "fsl,ls1021a-lpuart", .data = &ls1021a_data, },
{ .compatible = "fsl,ls1028a-lpuart", .data = &ls1028a_data, },
{ .compatible = "fsl,imx7ulp-lpuart", .data = &imx7ulp_data, },
{ .compatible = "fsl,imx8qxp-lpuart", .data = &imx8qxp_data, },
{ .compatible = "fsl,imxrt1050-lpuart", .data = &imxrt1050_data},
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
/* Forward declare this for the dma callbacks*/
static void lpuart_dma_tx_complete(void *arg);
static inline bool is_layerscape_lpuart(struct lpuart_port *sport)
{
return (sport->devtype == LS1021A_LPUART ||
sport->devtype == LS1028A_LPUART);
}
static inline bool is_imx7ulp_lpuart(struct lpuart_port *sport)
{
return sport->devtype == IMX7ULP_LPUART;
}
static inline bool is_imx8qxp_lpuart(struct lpuart_port *sport)
{
return sport->devtype == IMX8QXP_LPUART;
}
static inline u32 lpuart32_read(struct uart_port *port, u32 off)
{
switch (port->iotype) {
case UPIO_MEM32:
return readl(port->membase + off);
case UPIO_MEM32BE:
return ioread32be(port->membase + off);
default:
return 0;
}
}
static inline void lpuart32_write(struct uart_port *port, u32 val,
u32 off)
{
switch (port->iotype) {
case UPIO_MEM32:
writel(val, port->membase + off);
break;
case UPIO_MEM32BE:
iowrite32be(val, port->membase + off);
break;
}
}
static int __lpuart_enable_clks(struct lpuart_port *sport, bool is_en)
{
int ret = 0;
if (is_en) {
ret = clk_prepare_enable(sport->ipg_clk);
if (ret)
return ret;
ret = clk_prepare_enable(sport->baud_clk);
if (ret) {
clk_disable_unprepare(sport->ipg_clk);
return ret;
}
} else {
clk_disable_unprepare(sport->baud_clk);
clk_disable_unprepare(sport->ipg_clk);
}
return 0;
}
static unsigned int lpuart_get_baud_clk_rate(struct lpuart_port *sport)
{
if (is_imx8qxp_lpuart(sport))
return clk_get_rate(sport->baud_clk);
return clk_get_rate(sport->ipg_clk);
}
#define lpuart_enable_clks(x) __lpuart_enable_clks(x, true)
#define lpuart_disable_clks(x) __lpuart_enable_clks(x, false)
static void lpuart_stop_tx(struct uart_port *port)
{
unsigned char temp;
temp = readb(port->membase + UARTCR2);
temp &= ~(UARTCR2_TIE | UARTCR2_TCIE);
writeb(temp, port->membase + UARTCR2);
}
static void lpuart32_stop_tx(struct uart_port *port)
{
unsigned long temp;
temp = lpuart32_read(port, UARTCTRL);
temp &= ~(UARTCTRL_TIE | UARTCTRL_TCIE);
lpuart32_write(port, temp, UARTCTRL);
}
static void lpuart_stop_rx(struct uart_port *port)
{
unsigned char temp;
temp = readb(port->membase + UARTCR2);
writeb(temp & ~UARTCR2_RE, port->membase + UARTCR2);
}
static void lpuart32_stop_rx(struct uart_port *port)
{
unsigned long temp;
temp = lpuart32_read(port, UARTCTRL);
lpuart32_write(port, temp & ~UARTCTRL_RE, UARTCTRL);
}
static void lpuart_dma_tx(struct lpuart_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
struct scatterlist *sgl = sport->tx_sgl;
struct device *dev = sport->port.dev;
struct dma_chan *chan = sport->dma_tx_chan;
int ret;
if (sport->dma_tx_in_progress)
return;
sport->dma_tx_bytes = uart_circ_chars_pending(xmit);
if (xmit->tail < xmit->head || xmit->head == 0) {
sport->dma_tx_nents = 1;
sg_init_one(sgl, xmit->buf + xmit->tail, sport->dma_tx_bytes);
} else {
sport->dma_tx_nents = 2;
sg_init_table(sgl, 2);
sg_set_buf(sgl, xmit->buf + xmit->tail,
UART_XMIT_SIZE - xmit->tail);
sg_set_buf(sgl + 1, xmit->buf, xmit->head);
}
ret = dma_map_sg(chan->device->dev, sgl, sport->dma_tx_nents,
DMA_TO_DEVICE);
if (!ret) {
dev_err(dev, "DMA mapping error for TX.\n");
return;
}
sport->dma_tx_desc = dmaengine_prep_slave_sg(chan, sgl,
ret, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT);
if (!sport->dma_tx_desc) {
dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents,
DMA_TO_DEVICE);
dev_err(dev, "Cannot prepare TX slave DMA!\n");
return;
}
sport->dma_tx_desc->callback = lpuart_dma_tx_complete;
sport->dma_tx_desc->callback_param = sport;
sport->dma_tx_in_progress = true;
sport->dma_tx_cookie = dmaengine_submit(sport->dma_tx_desc);
dma_async_issue_pending(chan);
}
static bool lpuart_stopped_or_empty(struct uart_port *port)
{
return uart_circ_empty(&port->state->xmit) || uart_tx_stopped(port);
}
static void lpuart_dma_tx_complete(void *arg)
{
struct lpuart_port *sport = arg;
struct scatterlist *sgl = &sport->tx_sgl[0];
struct circ_buf *xmit = &sport->port.state->xmit;
struct dma_chan *chan = sport->dma_tx_chan;
unsigned long flags;
spin_lock_irqsave(&sport->port.lock, flags);
if (!sport->dma_tx_in_progress) {
spin_unlock_irqrestore(&sport->port.lock, flags);
return;
}
dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents,
DMA_TO_DEVICE);
xmit->tail = (xmit->tail + sport->dma_tx_bytes) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx += sport->dma_tx_bytes;
sport->dma_tx_in_progress = false;
spin_unlock_irqrestore(&sport->port.lock, flags);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
if (waitqueue_active(&sport->dma_wait)) {
wake_up(&sport->dma_wait);
return;
}
spin_lock_irqsave(&sport->port.lock, flags);
if (!lpuart_stopped_or_empty(&sport->port))
lpuart_dma_tx(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static dma_addr_t lpuart_dma_datareg_addr(struct lpuart_port *sport)
{
switch (sport->port.iotype) {
case UPIO_MEM32:
return sport->port.mapbase + UARTDATA;
case UPIO_MEM32BE:
return sport->port.mapbase + UARTDATA + sizeof(u32) - 1;
}
return sport->port.mapbase + UARTDR;
}
static int lpuart_dma_tx_request(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
struct dma_slave_config dma_tx_sconfig = {};
int ret;
dma_tx_sconfig.dst_addr = lpuart_dma_datareg_addr(sport);
dma_tx_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
dma_tx_sconfig.dst_maxburst = 1;
dma_tx_sconfig.direction = DMA_MEM_TO_DEV;
ret = dmaengine_slave_config(sport->dma_tx_chan, &dma_tx_sconfig);
if (ret) {
dev_err(sport->port.dev,
"DMA slave config failed, err = %d\n", ret);
return ret;
}
return 0;
}
static bool lpuart_is_32(struct lpuart_port *sport)
{
return sport->port.iotype == UPIO_MEM32 ||
sport->port.iotype == UPIO_MEM32BE;
}
static void lpuart_flush_buffer(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
struct dma_chan *chan = sport->dma_tx_chan;
u32 val;
if (sport->lpuart_dma_tx_use) {
if (sport->dma_tx_in_progress) {
dma_unmap_sg(chan->device->dev, &sport->tx_sgl[0],
sport->dma_tx_nents, DMA_TO_DEVICE);
sport->dma_tx_in_progress = false;
}
dmaengine_terminate_async(chan);
}
if (lpuart_is_32(sport)) {
val = lpuart32_read(&sport->port, UARTFIFO);
val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH;
lpuart32_write(&sport->port, val, UARTFIFO);
} else {
val = readb(sport->port.membase + UARTCFIFO);
val |= UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH;
writeb(val, sport->port.membase + UARTCFIFO);
}
}
static void lpuart_wait_bit_set(struct uart_port *port, unsigned int offset,
u8 bit)
{
while (!(readb(port->membase + offset) & bit))
cpu_relax();
}
static void lpuart32_wait_bit_set(struct uart_port *port, unsigned int offset,
u32 bit)
{
while (!(lpuart32_read(port, offset) & bit))
cpu_relax();
}
#if defined(CONFIG_CONSOLE_POLL)
static int lpuart_poll_init(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
unsigned long flags;
unsigned char temp;
sport->port.fifosize = 0;
spin_lock_irqsave(&sport->port.lock, flags);
/* Disable Rx & Tx */
writeb(0, sport->port.membase + UARTCR2);
temp = readb(sport->port.membase + UARTPFIFO);
/* Enable Rx and Tx FIFO */
writeb(temp | UARTPFIFO_RXFE | UARTPFIFO_TXFE,
sport->port.membase + UARTPFIFO);
/* flush Tx and Rx FIFO */
writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
sport->port.membase + UARTCFIFO);
/* explicitly clear RDRF */
if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) {
readb(sport->port.membase + UARTDR);
writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO);
}
writeb(0, sport->port.membase + UARTTWFIFO);
writeb(1, sport->port.membase + UARTRWFIFO);
/* Enable Rx and Tx */
writeb(UARTCR2_RE | UARTCR2_TE, sport->port.membase + UARTCR2);
spin_unlock_irqrestore(&sport->port.lock, flags);
return 0;
}
static void lpuart_poll_put_char(struct uart_port *port, unsigned char c)
{
/* drain */
lpuart_wait_bit_set(port, UARTSR1, UARTSR1_TDRE);
writeb(c, port->membase + UARTDR);
}
static int lpuart_poll_get_char(struct uart_port *port)
{
if (!(readb(port->membase + UARTSR1) & UARTSR1_RDRF))
return NO_POLL_CHAR;
return readb(port->membase + UARTDR);
}
static int lpuart32_poll_init(struct uart_port *port)
{
unsigned long flags;
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
u32 temp;
sport->port.fifosize = 0;
spin_lock_irqsave(&sport->port.lock, flags);
/* Disable Rx & Tx */
lpuart32_write(&sport->port, 0, UARTCTRL);
temp = lpuart32_read(&sport->port, UARTFIFO);
/* Enable Rx and Tx FIFO */
lpuart32_write(&sport->port, temp | UARTFIFO_RXFE | UARTFIFO_TXFE, UARTFIFO);
/* flush Tx and Rx FIFO */
lpuart32_write(&sport->port, UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH, UARTFIFO);
/* explicitly clear RDRF */
if (lpuart32_read(&sport->port, UARTSTAT) & UARTSTAT_RDRF) {
lpuart32_read(&sport->port, UARTDATA);
lpuart32_write(&sport->port, UARTFIFO_RXUF, UARTFIFO);
}
/* Enable Rx and Tx */
lpuart32_write(&sport->port, UARTCTRL_RE | UARTCTRL_TE, UARTCTRL);
spin_unlock_irqrestore(&sport->port.lock, flags);
return 0;
}
static void lpuart32_poll_put_char(struct uart_port *port, unsigned char c)
{
lpuart32_wait_bit_set(port, UARTSTAT, UARTSTAT_TDRE);
lpuart32_write(port, c, UARTDATA);
}
static int lpuart32_poll_get_char(struct uart_port *port)
{
if (!(lpuart32_read(port, UARTWATER) >> UARTWATER_RXCNT_OFF))
return NO_POLL_CHAR;
return lpuart32_read(port, UARTDATA);
}
#endif
static inline void lpuart_transmit_buffer(struct lpuart_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
if (sport->port.x_char) {
writeb(sport->port.x_char, sport->port.membase + UARTDR);
sport->port.icount.tx++;
sport->port.x_char = 0;
return;
}
if (lpuart_stopped_or_empty(&sport->port)) {
lpuart_stop_tx(&sport->port);
return;
}
while (!uart_circ_empty(xmit) &&
(readb(sport->port.membase + UARTTCFIFO) < sport->txfifo_size)) {
writeb(xmit->buf[xmit->tail], sport->port.membase + UARTDR);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx++;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
if (uart_circ_empty(xmit))
lpuart_stop_tx(&sport->port);
}
static inline void lpuart32_transmit_buffer(struct lpuart_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
unsigned long txcnt;
if (sport->port.x_char) {
lpuart32_write(&sport->port, sport->port.x_char, UARTDATA);
sport->port.icount.tx++;
sport->port.x_char = 0;
return;
}
if (lpuart_stopped_or_empty(&sport->port)) {
lpuart32_stop_tx(&sport->port);
return;
}
txcnt = lpuart32_read(&sport->port, UARTWATER);
txcnt = txcnt >> UARTWATER_TXCNT_OFF;
txcnt &= UARTWATER_COUNT_MASK;
while (!uart_circ_empty(xmit) && (txcnt < sport->txfifo_size)) {
lpuart32_write(&sport->port, xmit->buf[xmit->tail], UARTDATA);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx++;
txcnt = lpuart32_read(&sport->port, UARTWATER);
txcnt = txcnt >> UARTWATER_TXCNT_OFF;
txcnt &= UARTWATER_COUNT_MASK;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
if (uart_circ_empty(xmit))
lpuart32_stop_tx(&sport->port);
}
static void lpuart_start_tx(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
unsigned char temp;
temp = readb(port->membase + UARTCR2);
writeb(temp | UARTCR2_TIE, port->membase + UARTCR2);
if (sport->lpuart_dma_tx_use) {
if (!lpuart_stopped_or_empty(port))
lpuart_dma_tx(sport);
} else {
if (readb(port->membase + UARTSR1) & UARTSR1_TDRE)
lpuart_transmit_buffer(sport);
}
}
static void lpuart32_start_tx(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
unsigned long temp;
if (sport->lpuart_dma_tx_use) {
if (!lpuart_stopped_or_empty(port))
lpuart_dma_tx(sport);
} else {
temp = lpuart32_read(port, UARTCTRL);
lpuart32_write(port, temp | UARTCTRL_TIE, UARTCTRL);
if (lpuart32_read(port, UARTSTAT) & UARTSTAT_TDRE)
lpuart32_transmit_buffer(sport);
}
}
/* return TIOCSER_TEMT when transmitter is not busy */
static unsigned int lpuart_tx_empty(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
unsigned char sr1 = readb(port->membase + UARTSR1);
unsigned char sfifo = readb(port->membase + UARTSFIFO);
if (sport->dma_tx_in_progress)
return 0;
if (sr1 & UARTSR1_TC && sfifo & UARTSFIFO_TXEMPT)
return TIOCSER_TEMT;
return 0;
}
static unsigned int lpuart32_tx_empty(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
unsigned long stat = lpuart32_read(port, UARTSTAT);
unsigned long sfifo = lpuart32_read(port, UARTFIFO);
unsigned long ctrl = lpuart32_read(port, UARTCTRL);
if (sport->dma_tx_in_progress)
return 0;
/*
* LPUART Transmission Complete Flag may never be set while queuing a break
* character, so avoid checking for transmission complete when UARTCTRL_SBK
* is asserted.
*/
if ((stat & UARTSTAT_TC && sfifo & UARTFIFO_TXEMPT) || ctrl & UARTCTRL_SBK)
return TIOCSER_TEMT;
return 0;
}
static void lpuart_txint(struct lpuart_port *sport)
{
spin_lock(&sport->port.lock);
lpuart_transmit_buffer(sport);
spin_unlock(&sport->port.lock);
}
static void lpuart_rxint(struct lpuart_port *sport)
{
unsigned int flg, ignored = 0, overrun = 0;
struct tty_port *port = &sport->port.state->port;
unsigned char rx, sr;
spin_lock(&sport->port.lock);
while (!(readb(sport->port.membase + UARTSFIFO) & UARTSFIFO_RXEMPT)) {
flg = TTY_NORMAL;
sport->port.icount.rx++;
/*
* to clear the FE, OR, NF, FE, PE flags,
* read SR1 then read DR
*/
sr = readb(sport->port.membase + UARTSR1);
rx = readb(sport->port.membase + UARTDR);
if (uart_prepare_sysrq_char(&sport->port, rx))
continue;
if (sr & (UARTSR1_PE | UARTSR1_OR | UARTSR1_FE)) {
if (sr & UARTSR1_PE)
sport->port.icount.parity++;
else if (sr & UARTSR1_FE)
sport->port.icount.frame++;
if (sr & UARTSR1_OR)
overrun++;
if (sr & sport->port.ignore_status_mask) {
if (++ignored > 100)
goto out;
continue;
}
sr &= sport->port.read_status_mask;
if (sr & UARTSR1_PE)
flg = TTY_PARITY;
else if (sr & UARTSR1_FE)
flg = TTY_FRAME;
if (sr & UARTSR1_OR)
flg = TTY_OVERRUN;
sport->port.sysrq = 0;
}
if (tty_insert_flip_char(port, rx, flg) == 0)
sport->port.icount.buf_overrun++;
}
out:
if (overrun) {
sport->port.icount.overrun += overrun;
/*
* Overruns cause FIFO pointers to become missaligned.
* Flushing the receive FIFO reinitializes the pointers.
*/
writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO);
writeb(UARTSFIFO_RXOF, sport->port.membase + UARTSFIFO);
}
uart_unlock_and_check_sysrq(&sport->port);
tty_flip_buffer_push(port);
}
static void lpuart32_txint(struct lpuart_port *sport)
{
spin_lock(&sport->port.lock);
lpuart32_transmit_buffer(sport);
spin_unlock(&sport->port.lock);
}
static void lpuart32_rxint(struct lpuart_port *sport)
{
unsigned int flg, ignored = 0;
struct tty_port *port = &sport->port.state->port;
unsigned long rx, sr;
bool is_break;
spin_lock(&sport->port.lock);
while (!(lpuart32_read(&sport->port, UARTFIFO) & UARTFIFO_RXEMPT)) {
flg = TTY_NORMAL;
sport->port.icount.rx++;
/*
* to clear the FE, OR, NF, FE, PE flags,
* read STAT then read DATA reg
*/
sr = lpuart32_read(&sport->port, UARTSTAT);
rx = lpuart32_read(&sport->port, UARTDATA);
rx &= UARTDATA_MASK;
/*
* The LPUART can't distinguish between a break and a framing error,
* thus we assume it is a break if the received data is zero.
*/
is_break = (sr & UARTSTAT_FE) && !rx;
if (is_break && uart_handle_break(&sport->port))
continue;
if (uart_prepare_sysrq_char(&sport->port, rx))
continue;
if (sr & (UARTSTAT_PE | UARTSTAT_OR | UARTSTAT_FE)) {
if (sr & UARTSTAT_PE) {
sport->port.icount.parity++;
} else if (sr & UARTSTAT_FE) {
if (is_break)
sport->port.icount.brk++;
else
sport->port.icount.frame++;
}
if (sr & UARTSTAT_OR)
sport->port.icount.overrun++;
if (sr & sport->port.ignore_status_mask) {
if (++ignored > 100)
goto out;
continue;
}
sr &= sport->port.read_status_mask;
if (sr & UARTSTAT_PE) {
flg = TTY_PARITY;
} else if (sr & UARTSTAT_FE) {
if (is_break)
flg = TTY_BREAK;
else
flg = TTY_FRAME;
}
if (sr & UARTSTAT_OR)
flg = TTY_OVERRUN;
}
if (sport->is_cs7)
rx &= 0x7F;
if (tty_insert_flip_char(port, rx, flg) == 0)
sport->port.icount.buf_overrun++;
}
out:
uart_unlock_and_check_sysrq(&sport->port);
tty_flip_buffer_push(port);
}
static irqreturn_t lpuart_int(int irq, void *dev_id)
{
struct lpuart_port *sport = dev_id;
unsigned char sts;
sts = readb(sport->port.membase + UARTSR1);
/* SysRq, using dma, check for linebreak by framing err. */
if (sts & UARTSR1_FE && sport->lpuart_dma_rx_use) {
readb(sport->port.membase + UARTDR);
uart_handle_break(&sport->port);
/* linebreak produces some garbage, removing it */
writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO);
return IRQ_HANDLED;
}
if (sts & UARTSR1_RDRF && !sport->lpuart_dma_rx_use)
lpuart_rxint(sport);
if (sts & UARTSR1_TDRE && !sport->lpuart_dma_tx_use)
lpuart_txint(sport);
return IRQ_HANDLED;
}
static irqreturn_t lpuart32_int(int irq, void *dev_id)
{
struct lpuart_port *sport = dev_id;
unsigned long sts, rxcount;
sts = lpuart32_read(&sport->port, UARTSTAT);
rxcount = lpuart32_read(&sport->port, UARTWATER);
rxcount = rxcount >> UARTWATER_RXCNT_OFF;
if ((sts & UARTSTAT_RDRF || rxcount > 0) && !sport->lpuart_dma_rx_use)
lpuart32_rxint(sport);
if ((sts & UARTSTAT_TDRE) && !sport->lpuart_dma_tx_use)
lpuart32_txint(sport);
lpuart32_write(&sport->port, sts, UARTSTAT);
return IRQ_HANDLED;
}
static inline void lpuart_handle_sysrq_chars(struct uart_port *port,
unsigned char *p, int count)
{
while (count--) {
if (*p && uart_handle_sysrq_char(port, *p))
return;
p++;
}
}
static void lpuart_handle_sysrq(struct lpuart_port *sport)
{
struct circ_buf *ring = &sport->rx_ring;
int count;
if (ring->head < ring->tail) {
count = sport->rx_sgl.length - ring->tail;
lpuart_handle_sysrq_chars(&sport->port,
ring->buf + ring->tail, count);
ring->tail = 0;
}
if (ring->head > ring->tail) {
count = ring->head - ring->tail;
lpuart_handle_sysrq_chars(&sport->port,
ring->buf + ring->tail, count);
ring->tail = ring->head;
}
}
static int lpuart_tty_insert_flip_string(struct tty_port *port,
unsigned char *chars, size_t size, bool is_cs7)
{
int i;
if (is_cs7)
for (i = 0; i < size; i++)
chars[i] &= 0x7F;
return tty_insert_flip_string(port, chars, size);
}
static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
{
struct tty_port *port = &sport->port.state->port;
struct dma_tx_state state;
enum dma_status dmastat;
struct dma_chan *chan = sport->dma_rx_chan;
struct circ_buf *ring = &sport->rx_ring;
unsigned long flags;
int count, copied;
if (lpuart_is_32(sport)) {
unsigned long sr = lpuart32_read(&sport->port, UARTSTAT);
if (sr & (UARTSTAT_PE | UARTSTAT_FE)) {
/* Clear the error flags */
lpuart32_write(&sport->port, sr, UARTSTAT);
if (sr & UARTSTAT_PE)
sport->port.icount.parity++;
else if (sr & UARTSTAT_FE)
sport->port.icount.frame++;
}
} else {
unsigned char sr = readb(sport->port.membase + UARTSR1);
if (sr & (UARTSR1_PE | UARTSR1_FE)) {
unsigned char cr2;
/* Disable receiver during this operation... */
cr2 = readb(sport->port.membase + UARTCR2);
cr2 &= ~UARTCR2_RE;
writeb(cr2, sport->port.membase + UARTCR2);
/* Read DR to clear the error flags */
readb(sport->port.membase + UARTDR);
if (sr & UARTSR1_PE)
sport->port.icount.parity++;
else if (sr & UARTSR1_FE)
sport->port.icount.frame++;
/*
* At this point parity/framing error is
* cleared However, since the DMA already read
* the data register and we had to read it
* again after reading the status register to
* properly clear the flags, the FIFO actually
* underflowed... This requires a clearing of
* the FIFO...
*/
if (readb(sport->port.membase + UARTSFIFO) &
UARTSFIFO_RXUF) {
writeb(UARTSFIFO_RXUF,
sport->port.membase + UARTSFIFO);
writeb(UARTCFIFO_RXFLUSH,
sport->port.membase + UARTCFIFO);
}
cr2 |= UARTCR2_RE;
writeb(cr2, sport->port.membase + UARTCR2);
}
}
async_tx_ack(sport->dma_rx_desc);
spin_lock_irqsave(&sport->port.lock, flags);
dmastat = dmaengine_tx_status(chan, sport->dma_rx_cookie, &state);
if (dmastat == DMA_ERROR) {
dev_err(sport->port.dev, "Rx DMA transfer failed!\n");
spin_unlock_irqrestore(&sport->port.lock, flags);
return;
}
/* CPU claims ownership of RX DMA buffer */
dma_sync_sg_for_cpu(chan->device->dev, &sport->rx_sgl, 1,
DMA_FROM_DEVICE);
/*
* ring->head points to the end of data already written by the DMA.
* ring->tail points to the beginning of data to be read by the
* framework.
* The current transfer size should not be larger than the dma buffer
* length.
*/
ring->head = sport->rx_sgl.length - state.residue;
BUG_ON(ring->head > sport->rx_sgl.length);
/*
* Silent handling of keys pressed in the sysrq timeframe
*/
if (sport->port.sysrq) {
lpuart_handle_sysrq(sport);
goto exit;
}
/*
* At this point ring->head may point to the first byte right after the
* last byte of the dma buffer:
* 0 <= ring->head <= sport->rx_sgl.length
*
* However ring->tail must always points inside the dma buffer:
* 0 <= ring->tail <= sport->rx_sgl.length - 1
*
* Since we use a ring buffer, we have to handle the case
* where head is lower than tail. In such a case, we first read from
* tail to the end of the buffer then reset tail.
*/
if (ring->head < ring->tail) {
count = sport->rx_sgl.length - ring->tail;
copied = lpuart_tty_insert_flip_string(port, ring->buf + ring->tail,
count, sport->is_cs7);
if (copied != count)
sport->port.icount.buf_overrun++;
ring->tail = 0;
sport->port.icount.rx += copied;
}
/* Finally we read data from tail to head */
if (ring->tail < ring->head) {
count = ring->head - ring->tail;
copied = lpuart_tty_insert_flip_string(port, ring->buf + ring->tail,
count, sport->is_cs7);
if (copied != count)
sport->port.icount.buf_overrun++;
/* Wrap ring->head if needed */
if (ring->head >= sport->rx_sgl.length)
ring->head = 0;
ring->tail = ring->head;
sport->port.icount.rx += copied;
}
exit:
dma_sync_sg_for_device(chan->device->dev, &sport->rx_sgl, 1,
DMA_FROM_DEVICE);
spin_unlock_irqrestore(&sport->port.lock, flags);
tty_flip_buffer_push(port);
mod_timer(&sport->lpuart_timer, jiffies + sport->dma_rx_timeout);
}
static void lpuart_dma_rx_complete(void *arg)
{
struct lpuart_port *sport = arg;
lpuart_copy_rx_to_tty(sport);
}
static void lpuart_timer_func(struct timer_list *t)
{
struct lpuart_port *sport = from_timer(sport, t, lpuart_timer);
lpuart_copy_rx_to_tty(sport);
}
static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
{
struct dma_slave_config dma_rx_sconfig = {};
struct circ_buf *ring = &sport->rx_ring;
int ret, nent;
struct tty_port *port = &sport->port.state->port;
struct tty_struct *tty = port->tty;
struct ktermios *termios = &tty->termios;
struct dma_chan *chan = sport->dma_rx_chan;
unsigned int bits = tty_get_frame_size(termios->c_cflag);
unsigned int baud = tty_get_baud_rate(tty);
/*
* Calculate length of one DMA buffer size to keep latency below
* 10ms at any baud rate.
*/
sport->rx_dma_rng_buf_len = (DMA_RX_TIMEOUT * baud / bits / 1000) * 2;
sport->rx_dma_rng_buf_len = (1 << fls(sport->rx_dma_rng_buf_len));
if (sport->rx_dma_rng_buf_len < 16)
sport->rx_dma_rng_buf_len = 16;
ring->buf = kzalloc(sport->rx_dma_rng_buf_len, GFP_ATOMIC);
if (!ring->buf)
return -ENOMEM;
sg_init_one(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len);
nent = dma_map_sg(chan->device->dev, &sport->rx_sgl, 1,
DMA_FROM_DEVICE);
if (!nent) {
dev_err(sport->port.dev, "DMA Rx mapping error\n");
return -EINVAL;
}
dma_rx_sconfig.src_addr = lpuart_dma_datareg_addr(sport);
dma_rx_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
dma_rx_sconfig.src_maxburst = 1;
dma_rx_sconfig.direction = DMA_DEV_TO_MEM;
ret = dmaengine_slave_config(chan, &dma_rx_sconfig);
if (ret < 0) {
dev_err(sport->port.dev,
"DMA Rx slave config failed, err = %d\n", ret);
return ret;
}
sport->dma_rx_desc = dmaengine_prep_dma_cyclic(chan,
sg_dma_address(&sport->rx_sgl),
sport->rx_sgl.length,
sport->rx_sgl.length / 2,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT);
if (!sport->dma_rx_desc) {
dev_err(sport->port.dev, "Cannot prepare cyclic DMA\n");
return -EFAULT;
}
sport->dma_rx_desc->callback = lpuart_dma_rx_complete;
sport->dma_rx_desc->callback_param = sport;
sport->dma_rx_cookie = dmaengine_submit(sport->dma_rx_desc);
dma_async_issue_pending(chan);
if (lpuart_is_32(sport)) {
unsigned long temp = lpuart32_read(&sport->port, UARTBAUD);
lpuart32_write(&sport->port, temp | UARTBAUD_RDMAE, UARTBAUD);
} else {
writeb(readb(sport->port.membase + UARTCR5) | UARTCR5_RDMAS,
sport->port.membase + UARTCR5);
}
return 0;
}
static void lpuart_dma_rx_free(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
struct dma_chan *chan = sport->dma_rx_chan;
dmaengine_terminate_sync(chan);
del_timer_sync(&sport->lpuart_timer);
dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
kfree(sport->rx_ring.buf);
sport->rx_ring.tail = 0;
sport->rx_ring.head = 0;
sport->dma_rx_desc = NULL;
sport->dma_rx_cookie = -EINVAL;
}
static int lpuart_config_rs485(struct uart_port *port, struct ktermios *termios,
struct serial_rs485 *rs485)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
u8 modem = readb(sport->port.membase + UARTMODEM) &
~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE);
writeb(modem, sport->port.membase + UARTMODEM);
if (rs485->flags & SER_RS485_ENABLED) {
/* Enable auto RS-485 RTS mode */
modem |= UARTMODEM_TXRTSE;
/*
* The hardware defaults to RTS logic HIGH while transfer.
* Switch polarity in case RTS shall be logic HIGH
* after transfer.
* Note: UART is assumed to be active high.
*/
if (rs485->flags & SER_RS485_RTS_ON_SEND)
modem |= UARTMODEM_TXRTSPOL;
else if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
modem &= ~UARTMODEM_TXRTSPOL;
}
writeb(modem, sport->port.membase + UARTMODEM);
return 0;
}
static int lpuart32_config_rs485(struct uart_port *port, struct ktermios *termios,
struct serial_rs485 *rs485)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
unsigned long modem = lpuart32_read(&sport->port, UARTMODIR)
& ~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE);
lpuart32_write(&sport->port, modem, UARTMODIR);
if (rs485->flags & SER_RS485_ENABLED) {
/* Enable auto RS-485 RTS mode */
modem |= UARTMODEM_TXRTSE;
/*
* The hardware defaults to RTS logic HIGH while transfer.
* Switch polarity in case RTS shall be logic HIGH
* after transfer.
* Note: UART is assumed to be active high.
*/
if (rs485->flags & SER_RS485_RTS_ON_SEND)
modem |= UARTMODEM_TXRTSPOL;
else if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
modem &= ~UARTMODEM_TXRTSPOL;
}
lpuart32_write(&sport->port, modem, UARTMODIR);
return 0;
}
static unsigned int lpuart_get_mctrl(struct uart_port *port)
{
unsigned int mctrl = 0;
u8 reg;
reg = readb(port->membase + UARTCR1);
if (reg & UARTCR1_LOOPS)
mctrl |= TIOCM_LOOP;
return mctrl;
}
static unsigned int lpuart32_get_mctrl(struct uart_port *port)
{
unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
u32 reg;
reg = lpuart32_read(port, UARTCTRL);
if (reg & UARTCTRL_LOOPS)
mctrl |= TIOCM_LOOP;
return mctrl;
}
static void lpuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
u8 reg;
reg = readb(port->membase + UARTCR1);
/* for internal loopback we need LOOPS=1 and RSRC=0 */
reg &= ~(UARTCR1_LOOPS | UARTCR1_RSRC);
if (mctrl & TIOCM_LOOP)
reg |= UARTCR1_LOOPS;
writeb(reg, port->membase + UARTCR1);
}
static void lpuart32_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
u32 reg;
reg = lpuart32_read(port, UARTCTRL);
/* for internal loopback we need LOOPS=1 and RSRC=0 */
reg &= ~(UARTCTRL_LOOPS | UARTCTRL_RSRC);
if (mctrl & TIOCM_LOOP)
reg |= UARTCTRL_LOOPS;
lpuart32_write(port, reg, UARTCTRL);
}
static void lpuart_break_ctl(struct uart_port *port, int break_state)
{
unsigned char temp;
temp = readb(port->membase + UARTCR2) & ~UARTCR2_SBK;
if (break_state != 0)
temp |= UARTCR2_SBK;
writeb(temp, port->membase + UARTCR2);
}
static void lpuart32_break_ctl(struct uart_port *port, int break_state)
{
unsigned long temp;
temp = lpuart32_read(port, UARTCTRL);
/*
* LPUART IP now has two known bugs, one is CTS has higher priority than the
* break signal, which causes the break signal sending through UARTCTRL_SBK
* may impacted by the CTS input if the HW flow control is enabled. It
* exists on all platforms we support in this driver.
* Another bug is i.MX8QM LPUART may have an additional break character
* being sent after SBK was cleared.
* To avoid above two bugs, we use Transmit Data Inversion function to send
* the break signal instead of UARTCTRL_SBK.
*/
if (break_state != 0) {
/*
* Disable the transmitter to prevent any data from being sent out
* during break, then invert the TX line to send break.
*/
temp &= ~UARTCTRL_TE;
lpuart32_write(port, temp, UARTCTRL);
temp |= UARTCTRL_TXINV;
lpuart32_write(port, temp, UARTCTRL);
} else {
/* Disable the TXINV to turn off break and re-enable transmitter. */
temp &= ~UARTCTRL_TXINV;
lpuart32_write(port, temp, UARTCTRL);
temp |= UARTCTRL_TE;
lpuart32_write(port, temp, UARTCTRL);
}
}
static void lpuart_setup_watermark(struct lpuart_port *sport)
{
unsigned char val, cr2;
unsigned char cr2_saved;
cr2 = readb(sport->port.membase + UARTCR2);
cr2_saved = cr2;
cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_TE |
UARTCR2_RIE | UARTCR2_RE);
writeb(cr2, sport->port.membase + UARTCR2);
val = readb(sport->port.membase + UARTPFIFO);
writeb(val | UARTPFIFO_TXFE | UARTPFIFO_RXFE,
sport->port.membase + UARTPFIFO);
/* flush Tx and Rx FIFO */
writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
sport->port.membase + UARTCFIFO);
/* explicitly clear RDRF */
if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) {
readb(sport->port.membase + UARTDR);
writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO);
}
writeb(0, sport->port.membase + UARTTWFIFO);
writeb(sport->rx_watermark, sport->port.membase + UARTRWFIFO);
/* Restore cr2 */
writeb(cr2_saved, sport->port.membase + UARTCR2);
}
static void lpuart_setup_watermark_enable(struct lpuart_port *sport)
{
unsigned char cr2;
lpuart_setup_watermark(sport);
cr2 = readb(sport->port.membase + UARTCR2);
cr2 |= UARTCR2_RIE | UARTCR2_RE | UARTCR2_TE;
writeb(cr2, sport->port.membase + UARTCR2);
}
static void lpuart32_setup_watermark(struct lpuart_port *sport)
{
unsigned long val, ctrl;
unsigned long ctrl_saved;
ctrl = lpuart32_read(&sport->port, UARTCTRL);
ctrl_saved = ctrl;
ctrl &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_TE |
UARTCTRL_RIE | UARTCTRL_RE);
lpuart32_write(&sport->port, ctrl, UARTCTRL);
/* enable FIFO mode */
val = lpuart32_read(&sport->port, UARTFIFO);
val |= UARTFIFO_TXFE | UARTFIFO_RXFE;
val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH;
lpuart32_write(&sport->port, val, UARTFIFO);
/* set the watermark */
val = (sport->rx_watermark << UARTWATER_RXWATER_OFF) |
(0x0 << UARTWATER_TXWATER_OFF);
lpuart32_write(&sport->port, val, UARTWATER);
/* Restore cr2 */
lpuart32_write(&sport->port, ctrl_saved, UARTCTRL);
}
static void lpuart32_setup_watermark_enable(struct lpuart_port *sport)
{
u32 temp;
lpuart32_setup_watermark(sport);
temp = lpuart32_read(&sport->port, UARTCTRL);
temp |= UARTCTRL_RE | UARTCTRL_TE | UARTCTRL_ILIE;
lpuart32_write(&sport->port, temp, UARTCTRL);
}
static void rx_dma_timer_init(struct lpuart_port *sport)
{
timer_setup(&sport->lpuart_timer, lpuart_timer_func, 0);
sport->lpuart_timer.expires = jiffies + sport->dma_rx_timeout;
add_timer(&sport->lpuart_timer);
}
static void lpuart_request_dma(struct lpuart_port *sport)
{
sport->dma_tx_chan = dma_request_chan(sport->port.dev, "tx");
if (IS_ERR(sport->dma_tx_chan)) {
dev_dbg_once(sport->port.dev,
"DMA tx channel request failed, operating without tx DMA (%ld)\n",
PTR_ERR(sport->dma_tx_chan));
sport->dma_tx_chan = NULL;
}
sport->dma_rx_chan = dma_request_chan(sport->port.dev, "rx");
if (IS_ERR(sport->dma_rx_chan)) {
dev_dbg_once(sport->port.dev,
"DMA rx channel request failed, operating without rx DMA (%ld)\n",
PTR_ERR(sport->dma_rx_chan));
sport->dma_rx_chan = NULL;
}
}
static void lpuart_tx_dma_startup(struct lpuart_port *sport)
{
u32 uartbaud;
int ret;
if (uart_console(&sport->port))
goto err;
if (!sport->dma_tx_chan)
goto err;
ret = lpuart_dma_tx_request(&sport->port);
if (ret)
goto err;
init_waitqueue_head(&sport->dma_wait);
sport->lpuart_dma_tx_use = true;
if (lpuart_is_32(sport)) {
uartbaud = lpuart32_read(&sport->port, UARTBAUD);
lpuart32_write(&sport->port,
uartbaud | UARTBAUD_TDMAE, UARTBAUD);
} else {
writeb(readb(sport->port.membase + UARTCR5) |
UARTCR5_TDMAS, sport->port.membase + UARTCR5);
}
return;
err:
sport->lpuart_dma_tx_use = false;
}
static void lpuart_rx_dma_startup(struct lpuart_port *sport)
{
int ret;
unsigned char cr3;
if (uart_console(&sport->port))
goto err;
if (!sport->dma_rx_chan)
goto err;
ret = lpuart_start_rx_dma(sport);
if (ret)
goto err;
/* set Rx DMA timeout */
sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT);
if (!sport->dma_rx_timeout)
sport->dma_rx_timeout = 1;
sport->lpuart_dma_rx_use = true;
rx_dma_timer_init(sport);
if (sport->port.has_sysrq && !lpuart_is_32(sport)) {
cr3 = readb(sport->port.membase + UARTCR3);
cr3 |= UARTCR3_FEIE;
writeb(cr3, sport->port.membase + UARTCR3);
}
return;
err:
sport->lpuart_dma_rx_use = false;
}
static int lpuart_startup(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
unsigned long flags;
unsigned char temp;
/* determine FIFO size and enable FIFO mode */
temp = readb(sport->port.membase + UARTPFIFO);
sport->txfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_TXSIZE_OFF) &
UARTPFIFO_FIFOSIZE_MASK);
sport->port.fifosize = sport->txfifo_size;
sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_RXSIZE_OFF) &
UARTPFIFO_FIFOSIZE_MASK);
lpuart_request_dma(sport);
spin_lock_irqsave(&sport->port.lock, flags);
lpuart_setup_watermark_enable(sport);
lpuart_rx_dma_startup(sport);
lpuart_tx_dma_startup(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
return 0;
}
static void lpuart32_configure(struct lpuart_port *sport)
{
unsigned long temp;
temp = lpuart32_read(&sport->port, UARTCTRL);
if (!sport->lpuart_dma_rx_use)
temp |= UARTCTRL_RIE;
if (!sport->lpuart_dma_tx_use)
temp |= UARTCTRL_TIE;
lpuart32_write(&sport->port, temp, UARTCTRL);
}
static int lpuart32_startup(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
unsigned long flags;
unsigned long temp;
/* determine FIFO size */
temp = lpuart32_read(&sport->port, UARTFIFO);
sport->txfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_TXSIZE_OFF) &
UARTFIFO_FIFOSIZE_MASK);
sport->port.fifosize = sport->txfifo_size;
sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_RXSIZE_OFF) &
UARTFIFO_FIFOSIZE_MASK);
/*
* The LS1021A and LS1028A have a fixed FIFO depth of 16 words.
* Although they support the RX/TXSIZE fields, their encoding is
* different. Eg the reference manual states 0b101 is 16 words.
*/
if (is_layerscape_lpuart(sport)) {
sport->rxfifo_size = 16;
sport->txfifo_size = 16;
sport->port.fifosize = sport->txfifo_size;
}
lpuart_request_dma(sport);
spin_lock_irqsave(&sport->port.lock, flags);
lpuart32_setup_watermark_enable(sport);
lpuart_rx_dma_startup(sport);
lpuart_tx_dma_startup(sport);
lpuart32_configure(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
return 0;
}
static void lpuart_dma_shutdown(struct lpuart_port *sport)
{
if (sport->lpuart_dma_rx_use) {
lpuart_dma_rx_free(&sport->port);
sport->lpuart_dma_rx_use = false;
}
if (sport->lpuart_dma_tx_use) {
if (wait_event_interruptible_timeout(sport->dma_wait,
!sport->dma_tx_in_progress, msecs_to_jiffies(300)) <= 0) {
sport->dma_tx_in_progress = false;
dmaengine_terminate_sync(sport->dma_tx_chan);
}
sport->lpuart_dma_tx_use = false;
}
if (sport->dma_tx_chan)
dma_release_channel(sport->dma_tx_chan);
if (sport->dma_rx_chan)
dma_release_channel(sport->dma_rx_chan);
}
static void lpuart_shutdown(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
unsigned char temp;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
/* disable Rx/Tx and interrupts */
temp = readb(port->membase + UARTCR2);
temp &= ~(UARTCR2_TE | UARTCR2_RE |
UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE);
writeb(temp, port->membase + UARTCR2);
spin_unlock_irqrestore(&port->lock, flags);
lpuart_dma_shutdown(sport);
}
static void lpuart32_shutdown(struct uart_port *port)
{
struct lpuart_port *sport =
container_of(port, struct lpuart_port, port);
unsigned long temp;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
/* clear status */
temp = lpuart32_read(&sport->port, UARTSTAT);
lpuart32_write(&sport->port, temp, UARTSTAT);
/* disable Rx/Tx DMA */
temp = lpuart32_read(port, UARTBAUD);
temp &= ~(UARTBAUD_TDMAE | UARTBAUD_RDMAE);
lpuart32_write(port, temp, UARTBAUD);
/* disable Rx/Tx and interrupts */
temp = lpuart32_read(port, UARTCTRL);
temp &= ~(UARTCTRL_TE | UARTCTRL_RE |
UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE);
lpuart32_write(port, temp, UARTCTRL);
spin_unlock_irqrestore(&port->lock, flags);
lpuart_dma_shutdown(sport);
}
static void
lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
const struct ktermios *old)
{
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
unsigned long flags;
unsigned char cr1, old_cr1, old_cr2, cr3, cr4, bdh, modem;
unsigned int baud;
unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
unsigned int sbr, brfa;
cr1 = old_cr1 = readb(sport->port.membase + UARTCR1);
old_cr2 = readb(sport->port.membase + UARTCR2);
cr3 = readb(sport->port.membase + UARTCR3);
cr4 = readb(sport->port.membase + UARTCR4);
bdh = readb(sport->port.membase + UARTBDH);
modem = readb(sport->port.membase + UARTMODEM);
/*
* only support CS8 and CS7, and for CS7 must enable PE.
* supported mode:
* - (7,e/o,1)
* - (8,n,1)
* - (8,m/s,1)
* - (8,e/o,1)
*/
while ((termios->c_cflag & CSIZE) != CS8 &&
(termios->c_cflag & CSIZE) != CS7) {
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= old_csize;
old_csize = CS8;
}
if ((termios->c_cflag & CSIZE) == CS8 ||
(termios->c_cflag & CSIZE) == CS7)
cr1 = old_cr1 & ~UARTCR1_M;
if (termios->c_cflag & CMSPAR) {
if ((termios->c_cflag & CSIZE) != CS8) {
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= CS8;
}
cr1 |= UARTCR1_M;
}
/*
* When auto RS-485 RTS mode is enabled,
* hardware flow control need to be disabled.
*/
if (sport->port.rs485.flags & SER_RS485_ENABLED)
termios->c_cflag &= ~CRTSCTS;
if (termios->c_cflag & CRTSCTS)
modem |= UARTMODEM_RXRTSE | UARTMODEM_TXCTSE;
else
modem &= ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
termios->c_cflag &= ~CSTOPB;
/* parity must be enabled when CS7 to match 8-bits format */
if ((termios->c_cflag & CSIZE) == CS7)
termios->c_cflag |= PARENB;
if (termios->c_cflag & PARENB) {
if (termios->c_cflag & CMSPAR) {
cr1 &= ~UARTCR1_PE;
if (termios->c_cflag & PARODD)
cr3 |= UARTCR3_T8;
else
cr3 &= ~UARTCR3_T8;
} else {
cr1 |= UARTCR1_PE;
if ((termios->c_cflag & CSIZE) == CS8)
cr1 |= UARTCR1_M;
if (termios->c_cflag & PARODD)
cr1 |= UARTCR1_PT;
else
cr1 &= ~UARTCR1_PT;
}
} else {
cr1 &= ~UARTCR1_PE;
}
/* ask the core to calculate the divisor */
baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
/*
* Need to update the Ring buffer length according to the selected
* baud rate and restart Rx DMA path.
*
* Since timer function acqures sport->port.lock, need to stop before
* acquring same lock because otherwise del_timer_sync() can deadlock.
*/
if (old && sport->lpuart_dma_rx_use)
lpuart_dma_rx_free(&sport->port);
spin_lock_irqsave(&sport->port.lock, flags);
sport->port.read_status_mask = 0;
if (termios->c_iflag & INPCK)
sport->port.read_status_mask |= UARTSR1_FE | UARTSR1_PE;
if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
sport->port.read_status_mask |= UARTSR1_FE;
/* characters to ignore */
sport->port.ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
sport->port.ignore_status_mask |= UARTSR1_PE;
if (termios->c_iflag & IGNBRK) {
sport->port.ignore_status_mask |= UARTSR1_FE;
/*
* if we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
sport->port.ignore_status_mask |= UARTSR1_OR;
}
/* update the per-port timeout */
uart_update_timeout(port, termios->c_cflag, baud);
/* wait transmit engin complete */
lpuart_wait_bit_set(&sport->port, UARTSR1, UARTSR1_TC);
/* disable transmit and receive */
writeb(old_cr2 & ~(UARTCR2_TE | UARTCR2_RE),
sport->port.membase + UARTCR2);
sbr = sport->port.uartclk / (16 * baud);
brfa = ((sport->port.uartclk - (16 * sbr * baud)) * 2) / baud;
bdh &= ~UARTBDH_SBR_MASK;
bdh |= (sbr >> 8) & 0x1F;
cr4 &= ~UARTCR4_BRFA_MASK;
brfa &= UARTCR4_BRFA_MASK;
writeb(cr4 | brfa, sport->port.membase + UARTCR4);
writeb(bdh, sport->port.membase + UARTBDH);
writeb(sbr & 0xFF, sport->port.membase + UARTBDL);
writeb(cr3, sport->port.membase + UARTCR3);
writeb(cr1, sport->port.membase + UARTCR1);
writeb(modem, sport->port.membase + UARTMODEM);
/* restore control register */
writeb(old_cr2, sport->port.membase + UARTCR2);
if (old && sport->lpuart_dma_rx_use) {
if (!lpuart_start_rx_dma(sport))
rx_dma_timer_init(sport);
else
sport->lpuart_dma_rx_use = false;
}
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static void __lpuart32_serial_setbrg(struct uart_port *port,
unsigned int baudrate, bool use_rx_dma,
bool use_tx_dma)
{
u32 sbr, osr, baud_diff, tmp_osr, tmp_sbr, tmp_diff, tmp;
u32 clk = port->uartclk;
/*
* The idea is to use the best OSR (over-sampling rate) possible.
* Note, OSR is typically hard-set to 16 in other LPUART instantiations.
* Loop to find the best OSR value possible, one that generates minimum
* baud_diff iterate through the rest of the supported values of OSR.
*
* Calculation Formula:
* Baud Rate = baud clock / ((OSR+1) × SBR)
*/
baud_diff = baudrate;
osr = 0;
sbr = 0;
for (tmp_osr = 4; tmp_osr <= 32; tmp_osr++) {
/* calculate the temporary sbr value */
tmp_sbr = (clk / (baudrate * tmp_osr));
if (tmp_sbr == 0)
tmp_sbr = 1;
/*
* calculate the baud rate difference based on the temporary
* osr and sbr values
*/
tmp_diff = clk / (tmp_osr * tmp_sbr) - baudrate;
/* select best values between sbr and sbr+1 */
tmp = clk / (tmp_osr * (tmp_sbr + 1));
if (tmp_diff > (baudrate - tmp)) {
tmp_diff = baudrate - tmp;
tmp_sbr++;
}
if (tmp_sbr > UARTBAUD_SBR_MASK)
continue;
if (tmp_diff <= baud_diff) {
baud_diff = tmp_diff;
osr = tmp_osr;
sbr = tmp_sbr;
if (!baud_diff)
break;
}
}
/* handle buadrate outside acceptable rate */
if (baud_diff > ((baudrate / 100) * 3))
dev_warn(port->dev,
"unacceptable baud rate difference of more than 3%%\n");
tmp = lpuart32_read(port, UARTBAUD);
if ((osr > 3) && (osr < 8))
tmp |= UARTBAUD_BOTHEDGE;
tmp &= ~(UARTBAUD_OSR_MASK << UARTBAUD_OSR_SHIFT);
tmp |= ((osr-1) & UARTBAUD_OSR_MASK) << UARTBAUD_OSR_SHIFT;
tmp &= ~UARTBAUD_SBR_MASK;
tmp |= sbr & UARTBAUD_SBR_MASK;
if (!use_rx_dma)
tmp &= ~UARTBAUD_RDMAE;
if (!use_tx_dma)
tmp &= ~UARTBAUD_TDMAE;
lpuart32_write(port, tmp, UARTBAUD);
}
static void lpuart32_serial_setbrg(struct lpuart_port *sport,
unsigned int baudrate)
{
__lpuart32_serial_setbrg(&sport->port, baudrate,
sport->lpuart_dma_rx_use,
sport->lpuart_dma_tx_use);
}
static void
lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
const struct ktermios *old)
{
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
unsigned long flags;
unsigned long ctrl, old_ctrl, bd, modem;
unsigned int baud;
unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
ctrl = old_ctrl = lpuart32_read(&sport->port, UARTCTRL);
bd = lpuart32_read(&sport->port, UARTBAUD);
modem = lpuart32_read(&sport->port, UARTMODIR);
sport->is_cs7 = false;
/*
* only support CS8 and CS7, and for CS7 must enable PE.
* supported mode:
* - (7,e/o,1)
* - (8,n,1)
* - (8,m/s,1)
* - (8,e/o,1)
*/
while ((termios->c_cflag & CSIZE) != CS8 &&
(termios->c_cflag & CSIZE) != CS7) {
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= old_csize;
old_csize = CS8;
}
if ((termios->c_cflag & CSIZE) == CS8 ||
(termios->c_cflag & CSIZE) == CS7)
ctrl = old_ctrl & ~UARTCTRL_M;
if (termios->c_cflag & CMSPAR) {
if ((termios->c_cflag & CSIZE) != CS8) {
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= CS8;
}
ctrl |= UARTCTRL_M;
}
/*
* When auto RS-485 RTS mode is enabled,
* hardware flow control need to be disabled.
*/
if (sport->port.rs485.flags & SER_RS485_ENABLED)
termios->c_cflag &= ~CRTSCTS;
if (termios->c_cflag & CRTSCTS)
modem |= UARTMODIR_RXRTSE | UARTMODIR_TXCTSE;
else
modem &= ~(UARTMODIR_RXRTSE | UARTMODIR_TXCTSE);
if (termios->c_cflag & CSTOPB)
bd |= UARTBAUD_SBNS;
else
bd &= ~UARTBAUD_SBNS;
/* parity must be enabled when CS7 to match 8-bits format */
if ((termios->c_cflag & CSIZE) == CS7)
termios->c_cflag |= PARENB;
if ((termios->c_cflag & PARENB)) {
if (termios->c_cflag & CMSPAR) {
ctrl &= ~UARTCTRL_PE;
ctrl |= UARTCTRL_M;
} else {
ctrl |= UARTCTRL_PE;
if ((termios->c_cflag & CSIZE) == CS8)
ctrl |= UARTCTRL_M;
if (termios->c_cflag & PARODD)
ctrl |= UARTCTRL_PT;
else
ctrl &= ~UARTCTRL_PT;
}
} else {
ctrl &= ~UARTCTRL_PE;
}
/* ask the core to calculate the divisor */
baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 4);
/*
* Need to update the Ring buffer length according to the selected
* baud rate and restart Rx DMA path.
*
* Since timer function acqures sport->port.lock, need to stop before
* acquring same lock because otherwise del_timer_sync() can deadlock.
*/
if (old && sport->lpuart_dma_rx_use)
lpuart_dma_rx_free(&sport->port);
spin_lock_irqsave(&sport->port.lock, flags);
sport->port.read_status_mask = 0;
if (termios->c_iflag & INPCK)
sport->port.read_status_mask |= UARTSTAT_FE | UARTSTAT_PE;
if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
sport->port.read_status_mask |= UARTSTAT_FE;
/* characters to ignore */
sport->port.ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
sport->port.ignore_status_mask |= UARTSTAT_PE;
if (termios->c_iflag & IGNBRK) {
sport->port.ignore_status_mask |= UARTSTAT_FE;
/*
* if we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
sport->port.ignore_status_mask |= UARTSTAT_OR;
}
/* update the per-port timeout */
uart_update_timeout(port, termios->c_cflag, baud);
/*
* LPUART Transmission Complete Flag may never be set while queuing a break
* character, so skip waiting for transmission complete when UARTCTRL_SBK is
* asserted.
*/
if (!(old_ctrl & UARTCTRL_SBK)) {
lpuart32_write(&sport->port, 0, UARTMODIR);
lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC);
}
/* disable transmit and receive */
lpuart32_write(&sport->port, old_ctrl & ~(UARTCTRL_TE | UARTCTRL_RE),
UARTCTRL);
lpuart32_write(&sport->port, bd, UARTBAUD);
lpuart32_serial_setbrg(sport, baud);
lpuart32_write(&sport->port, modem, UARTMODIR);
lpuart32_write(&sport->port, ctrl, UARTCTRL);
/* restore control register */
if ((ctrl & (UARTCTRL_PE | UARTCTRL_M)) == UARTCTRL_PE)
sport->is_cs7 = true;
if (old && sport->lpuart_dma_rx_use) {
if (!lpuart_start_rx_dma(sport))
rx_dma_timer_init(sport);
else
sport->lpuart_dma_rx_use = false;
}
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static const char *lpuart_type(struct uart_port *port)
{
return "FSL_LPUART";
}
static void lpuart_release_port(struct uart_port *port)
{
/* nothing to do */
}
static int lpuart_request_port(struct uart_port *port)
{
return 0;
}
/* configure/autoconfigure the port */
static void lpuart_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE)
port->type = PORT_LPUART;
}
static int lpuart_verify_port(struct uart_port *port, struct serial_struct *ser)
{
int ret = 0;
if (ser->type != PORT_UNKNOWN && ser->type != PORT_LPUART)
ret = -EINVAL;
if (port->irq != ser->irq)
ret = -EINVAL;
if (ser->io_type != UPIO_MEM)
ret = -EINVAL;
if (port->uartclk / 16 != ser->baud_base)
ret = -EINVAL;
if (port->iobase != ser->port)
ret = -EINVAL;
if (ser->hub6 != 0)
ret = -EINVAL;
return ret;
}
static const struct uart_ops lpuart_pops = {
.tx_empty = lpuart_tx_empty,
.set_mctrl = lpuart_set_mctrl,
.get_mctrl = lpuart_get_mctrl,
.stop_tx = lpuart_stop_tx,
.start_tx = lpuart_start_tx,
.stop_rx = lpuart_stop_rx,
.break_ctl = lpuart_break_ctl,
.startup = lpuart_startup,
.shutdown = lpuart_shutdown,
.set_termios = lpuart_set_termios,
.type = lpuart_type,
.request_port = lpuart_request_port,
.release_port = lpuart_release_port,
.config_port = lpuart_config_port,
.verify_port = lpuart_verify_port,
.flush_buffer = lpuart_flush_buffer,
#if defined(CONFIG_CONSOLE_POLL)
.poll_init = lpuart_poll_init,
.poll_get_char = lpuart_poll_get_char,
.poll_put_char = lpuart_poll_put_char,
#endif
};
static const struct uart_ops lpuart32_pops = {
.tx_empty = lpuart32_tx_empty,
.set_mctrl = lpuart32_set_mctrl,
.get_mctrl = lpuart32_get_mctrl,
.stop_tx = lpuart32_stop_tx,
.start_tx = lpuart32_start_tx,
.stop_rx = lpuart32_stop_rx,
.break_ctl = lpuart32_break_ctl,
.startup = lpuart32_startup,
.shutdown = lpuart32_shutdown,
.set_termios = lpuart32_set_termios,
.type = lpuart_type,
.request_port = lpuart_request_port,
.release_port = lpuart_release_port,
.config_port = lpuart_config_port,
.verify_port = lpuart_verify_port,
.flush_buffer = lpuart_flush_buffer,
#if defined(CONFIG_CONSOLE_POLL)
.poll_init = lpuart32_poll_init,
.poll_get_char = lpuart32_poll_get_char,
.poll_put_char = lpuart32_poll_put_char,
#endif
};
static struct lpuart_port *lpuart_ports[UART_NR];
#ifdef CONFIG_SERIAL_FSL_LPUART_CONSOLE
static void lpuart_console_putchar(struct uart_port *port, unsigned char ch)
{
lpuart_wait_bit_set(port, UARTSR1, UARTSR1_TDRE);
writeb(ch, port->membase + UARTDR);
}
static void lpuart32_console_putchar(struct uart_port *port, unsigned char ch)
{
lpuart32_wait_bit_set(port, UARTSTAT, UARTSTAT_TDRE);
lpuart32_write(port, ch, UARTDATA);
}
static void
lpuart_console_write(struct console *co, const char *s, unsigned int count)
{
struct lpuart_port *sport = lpuart_ports[co->index];
unsigned char old_cr2, cr2;
unsigned long flags;
int locked = 1;
if (oops_in_progress)
locked = spin_trylock_irqsave(&sport->port.lock, flags);
else
spin_lock_irqsave(&sport->port.lock, flags);
/* first save CR2 and then disable interrupts */
cr2 = old_cr2 = readb(sport->port.membase + UARTCR2);
cr2 |= UARTCR2_TE | UARTCR2_RE;
cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE);
writeb(cr2, sport->port.membase + UARTCR2);
uart_console_write(&sport->port, s, count, lpuart_console_putchar);
/* wait for transmitter finish complete and restore CR2 */
lpuart_wait_bit_set(&sport->port, UARTSR1, UARTSR1_TC);
writeb(old_cr2, sport->port.membase + UARTCR2);
if (locked)
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static void
lpuart32_console_write(struct console *co, const char *s, unsigned int count)
{
struct lpuart_port *sport = lpuart_ports[co->index];
unsigned long old_cr, cr;
unsigned long flags;
int locked = 1;
if (oops_in_progress)
locked = spin_trylock_irqsave(&sport->port.lock, flags);
else
spin_lock_irqsave(&sport->port.lock, flags);
/* first save CR2 and then disable interrupts */
cr = old_cr = lpuart32_read(&sport->port, UARTCTRL);
cr |= UARTCTRL_TE | UARTCTRL_RE;
cr &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE);
lpuart32_write(&sport->port, cr, UARTCTRL);
uart_console_write(&sport->port, s, count, lpuart32_console_putchar);
/* wait for transmitter finish complete and restore CR2 */
lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC);
lpuart32_write(&sport->port, old_cr, UARTCTRL);
if (locked)
spin_unlock_irqrestore(&sport->port.lock, flags);
}
/*
* if the port was already initialised (eg, by a boot loader),
* try to determine the current setup.
*/
static void __init
lpuart_console_get_options(struct lpuart_port *sport, int *baud,
int *parity, int *bits)
{
unsigned char cr, bdh, bdl, brfa;
unsigned int sbr, uartclk, baud_raw;
cr = readb(sport->port.membase + UARTCR2);
cr &= UARTCR2_TE | UARTCR2_RE;
if (!cr)
return;
/* ok, the port was enabled */
cr = readb(sport->port.membase + UARTCR1);
*parity = 'n';
if (cr & UARTCR1_PE) {
if (cr & UARTCR1_PT)
*parity = 'o';
else
*parity = 'e';
}
if (cr & UARTCR1_M)
*bits = 9;
else
*bits = 8;
bdh = readb(sport->port.membase + UARTBDH);
bdh &= UARTBDH_SBR_MASK;
bdl = readb(sport->port.membase + UARTBDL);
sbr = bdh;
sbr <<= 8;
sbr |= bdl;
brfa = readb(sport->port.membase + UARTCR4);
brfa &= UARTCR4_BRFA_MASK;
uartclk = lpuart_get_baud_clk_rate(sport);
/*
* baud = mod_clk/(16*(sbr[13]+(brfa)/32)
*/
baud_raw = uartclk / (16 * (sbr + brfa / 32));
if (*baud != baud_raw)
dev_info(sport->port.dev, "Serial: Console lpuart rounded baud rate"
"from %d to %d\n", baud_raw, *baud);
}
static void __init
lpuart32_console_get_options(struct lpuart_port *sport, int *baud,
int *parity, int *bits)
{
unsigned long cr, bd;
unsigned int sbr, uartclk, baud_raw;
cr = lpuart32_read(&sport->port, UARTCTRL);
cr &= UARTCTRL_TE | UARTCTRL_RE;
if (!cr)
return;
/* ok, the port was enabled */
cr = lpuart32_read(&sport->port, UARTCTRL);
*parity = 'n';
if (cr & UARTCTRL_PE) {
if (cr & UARTCTRL_PT)
*parity = 'o';
else
*parity = 'e';
}
if (cr & UARTCTRL_M)
*bits = 9;
else
*bits = 8;
bd = lpuart32_read(&sport->port, UARTBAUD);
bd &= UARTBAUD_SBR_MASK;
if (!bd)
return;
sbr = bd;
uartclk = lpuart_get_baud_clk_rate(sport);
/*
* baud = mod_clk/(16*(sbr[13]+(brfa)/32)
*/
baud_raw = uartclk / (16 * sbr);
if (*baud != baud_raw)
dev_info(sport->port.dev, "Serial: Console lpuart rounded baud rate"
"from %d to %d\n", baud_raw, *baud);
}
static int __init lpuart_console_setup(struct console *co, char *options)
{
struct lpuart_port *sport;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
/*
* check whether an invalid uart number has been specified, and
* if so, search for the first available port that does have
* console support.
*/
if (co->index == -1 || co->index >= ARRAY_SIZE(lpuart_ports))
co->index = 0;
sport = lpuart_ports[co->index];
if (sport == NULL)
return -ENODEV;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
if (lpuart_is_32(sport))
lpuart32_console_get_options(sport, &baud, &parity, &bits);
else
lpuart_console_get_options(sport, &baud, &parity, &bits);
if (lpuart_is_32(sport))
lpuart32_setup_watermark(sport);
else
lpuart_setup_watermark(sport);
return uart_set_options(&sport->port, co, baud, parity, bits, flow);
}
static struct uart_driver lpuart_reg;
static struct console lpuart_console = {
.name = DEV_NAME,
.write = lpuart_console_write,
.device = uart_console_device,
.setup = lpuart_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &lpuart_reg,
};
static struct console lpuart32_console = {
.name = DEV_NAME,
.write = lpuart32_console_write,
.device = uart_console_device,
.setup = lpuart_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &lpuart_reg,
};
static void lpuart_early_write(struct console *con, const char *s, unsigned n)
{
struct earlycon_device *dev = con->data;
uart_console_write(&dev->port, s, n, lpuart_console_putchar);
}
static void lpuart32_early_write(struct console *con, const char *s, unsigned n)
{
struct earlycon_device *dev = con->data;
uart_console_write(&dev->port, s, n, lpuart32_console_putchar);
}
static int __init lpuart_early_console_setup(struct earlycon_device *device,
const char *opt)
{
if (!device->port.membase)
return -ENODEV;
device->con->write = lpuart_early_write;
return 0;
}
static int __init lpuart32_early_console_setup(struct earlycon_device *device,
const char *opt)
{
if (!device->port.membase)
return -ENODEV;
if (device->port.iotype != UPIO_MEM32)
device->port.iotype = UPIO_MEM32BE;
device->con->write = lpuart32_early_write;
return 0;
}
static int __init ls1028a_early_console_setup(struct earlycon_device *device,
const char *opt)
{
u32 cr;
if (!device->port.membase)
return -ENODEV;
device->port.iotype = UPIO_MEM32;
device->con->write = lpuart32_early_write;
/* set the baudrate */
if (device->port.uartclk && device->baud)
__lpuart32_serial_setbrg(&device->port, device->baud,
false, false);
/* enable transmitter */
cr = lpuart32_read(&device->port, UARTCTRL);
cr |= UARTCTRL_TE;
lpuart32_write(&device->port, cr, UARTCTRL);
return 0;
}
static int __init lpuart32_imx_early_console_setup(struct earlycon_device *device,
const char *opt)
{
if (!device->port.membase)
return -ENODEV;
device->port.iotype = UPIO_MEM32;
device->port.membase += IMX_REG_OFF;
device->con->write = lpuart32_early_write;
return 0;
}
OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup);
OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup);
OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1028a-lpuart", ls1028a_early_console_setup);
OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart", lpuart32_imx_early_console_setup);
OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8ulp-lpuart", lpuart32_imx_early_console_setup);
OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8qxp-lpuart", lpuart32_imx_early_console_setup);
OF_EARLYCON_DECLARE(lpuart32, "fsl,imxrt1050-lpuart", lpuart32_imx_early_console_setup);
EARLYCON_DECLARE(lpuart, lpuart_early_console_setup);
EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup);
#define LPUART_CONSOLE (&lpuart_console)
#define LPUART32_CONSOLE (&lpuart32_console)
#else
#define LPUART_CONSOLE NULL
#define LPUART32_CONSOLE NULL
#endif
static struct uart_driver lpuart_reg = {
.owner = THIS_MODULE,
.driver_name = DRIVER_NAME,
.dev_name = DEV_NAME,
.nr = ARRAY_SIZE(lpuart_ports),
.cons = LPUART_CONSOLE,
};
static const struct serial_rs485 lpuart_rs485_supported = {
.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
/* delay_rts_* and RX_DURING_TX are not supported */
};
static int lpuart_global_reset(struct lpuart_port *sport)
{
struct uart_port *port = &sport->port;
void __iomem *global_addr;
unsigned long ctrl, bd;
unsigned int val = 0;
int ret;
ret = clk_prepare_enable(sport->ipg_clk);
if (ret) {
dev_err(sport->port.dev, "failed to enable uart ipg clk: %d\n", ret);
return ret;
}
if (is_imx7ulp_lpuart(sport) || is_imx8qxp_lpuart(sport)) {
/*
* If the transmitter is used by earlycon, wait for transmit engine to
* complete and then reset.
*/
ctrl = lpuart32_read(port, UARTCTRL);
if (ctrl & UARTCTRL_TE) {
bd = lpuart32_read(&sport->port, UARTBAUD);
if (read_poll_timeout(lpuart32_tx_empty, val, val, 1, 100000, false,
port)) {
dev_warn(sport->port.dev,
"timeout waiting for transmit engine to complete\n");
clk_disable_unprepare(sport->ipg_clk);
return 0;
}
}
global_addr = port->membase + UART_GLOBAL - IMX_REG_OFF;
writel(UART_GLOBAL_RST, global_addr);
usleep_range(GLOBAL_RST_MIN_US, GLOBAL_RST_MAX_US);
writel(0, global_addr);
usleep_range(GLOBAL_RST_MIN_US, GLOBAL_RST_MAX_US);
/* Recover the transmitter for earlycon. */
if (ctrl & UARTCTRL_TE) {
lpuart32_write(port, bd, UARTBAUD);
lpuart32_write(port, ctrl, UARTCTRL);
}
}
clk_disable_unprepare(sport->ipg_clk);
return 0;
}
static int lpuart_probe(struct platform_device *pdev)
{
const struct lpuart_soc_data *sdata = of_device_get_match_data(&pdev->dev);
struct device_node *np = pdev->dev.of_node;
struct lpuart_port *sport;
struct resource *res;
irq_handler_t handler;
int ret;
sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
if (!sport)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
sport->port.membase = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(sport->port.membase))
return PTR_ERR(sport->port.membase);
sport->port.membase += sdata->reg_off;
sport->port.mapbase = res->start + sdata->reg_off;
sport->port.dev = &pdev->dev;
sport->port.type = PORT_LPUART;
sport->devtype = sdata->devtype;
sport->rx_watermark = sdata->rx_watermark;
ret = platform_get_irq(pdev, 0);
if (ret < 0)
return ret;
sport->port.irq = ret;
sport->port.iotype = sdata->iotype;
if (lpuart_is_32(sport))
sport->port.ops = &lpuart32_pops;
else
sport->port.ops = &lpuart_pops;
sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_FSL_LPUART_CONSOLE);
sport->port.flags = UPF_BOOT_AUTOCONF;
if (lpuart_is_32(sport))
sport->port.rs485_config = lpuart32_config_rs485;
else
sport->port.rs485_config = lpuart_config_rs485;
sport->port.rs485_supported = lpuart_rs485_supported;
sport->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
if (IS_ERR(sport->ipg_clk)) {
ret = PTR_ERR(sport->ipg_clk);
dev_err(&pdev->dev, "failed to get uart ipg clk: %d\n", ret);
return ret;
}
sport->baud_clk = NULL;
if (is_imx8qxp_lpuart(sport)) {
sport->baud_clk = devm_clk_get(&pdev->dev, "baud");
if (IS_ERR(sport->baud_clk)) {
ret = PTR_ERR(sport->baud_clk);
dev_err(&pdev->dev, "failed to get uart baud clk: %d\n", ret);
return ret;
}
}
ret = of_alias_get_id(np, "serial");
if (ret < 0) {
dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
return ret;
}
if (ret >= ARRAY_SIZE(lpuart_ports)) {
dev_err(&pdev->dev, "serial%d out of range\n", ret);
return -EINVAL;
}
sport->port.line = ret;
ret = lpuart_enable_clks(sport);
if (ret)
return ret;
sport->port.uartclk = lpuart_get_baud_clk_rate(sport);
lpuart_ports[sport->port.line] = sport;
platform_set_drvdata(pdev, &sport->port);
if (lpuart_is_32(sport)) {
lpuart_reg.cons = LPUART32_CONSOLE;
handler = lpuart32_int;
} else {
lpuart_reg.cons = LPUART_CONSOLE;
handler = lpuart_int;
}
ret = lpuart_global_reset(sport);
if (ret)
goto failed_reset;
ret = uart_get_rs485_mode(&sport->port);
if (ret)
goto failed_get_rs485;
ret = uart_add_one_port(&lpuart_reg, &sport->port);
if (ret)
goto failed_attach_port;
ret = devm_request_irq(&pdev->dev, sport->port.irq, handler, 0,
DRIVER_NAME, sport);
if (ret)
goto failed_irq_request;
return 0;
failed_irq_request:
uart_remove_one_port(&lpuart_reg, &sport->port);
failed_attach_port:
failed_get_rs485:
failed_reset:
lpuart_disable_clks(sport);
return ret;
}
static int lpuart_remove(struct platform_device *pdev)
{
struct lpuart_port *sport = platform_get_drvdata(pdev);
uart_remove_one_port(&lpuart_reg, &sport->port);
lpuart_disable_clks(sport);
if (sport->dma_tx_chan)
dma_release_channel(sport->dma_tx_chan);
if (sport->dma_rx_chan)
dma_release_channel(sport->dma_rx_chan);
return 0;
}
static int __maybe_unused lpuart_suspend(struct device *dev)
{
struct lpuart_port *sport = dev_get_drvdata(dev);
unsigned long temp;
bool irq_wake;
if (lpuart_is_32(sport)) {
/* disable Rx/Tx and interrupts */
temp = lpuart32_read(&sport->port, UARTCTRL);
temp &= ~(UARTCTRL_TE | UARTCTRL_TIE | UARTCTRL_TCIE);
lpuart32_write(&sport->port, temp, UARTCTRL);
} else {
/* disable Rx/Tx and interrupts */
temp = readb(sport->port.membase + UARTCR2);
temp &= ~(UARTCR2_TE | UARTCR2_TIE | UARTCR2_TCIE);
writeb(temp, sport->port.membase + UARTCR2);
}
uart_suspend_port(&lpuart_reg, &sport->port);
/* uart_suspend_port() might set wakeup flag */
irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq));
if (sport->lpuart_dma_rx_use) {
/*
* EDMA driver during suspend will forcefully release any
* non-idle DMA channels. If port wakeup is enabled or if port
* is console port or 'no_console_suspend' is set the Rx DMA
* cannot resume as expected, hence gracefully release the
* Rx DMA path before suspend and start Rx DMA path on resume.
*/
if (irq_wake) {
lpuart_dma_rx_free(&sport->port);
}
/* Disable Rx DMA to use UART port as wakeup source */
if (lpuart_is_32(sport)) {
temp = lpuart32_read(&sport->port, UARTBAUD);
lpuart32_write(&sport->port, temp & ~UARTBAUD_RDMAE,
UARTBAUD);
} else {
writeb(readb(sport->port.membase + UARTCR5) &
~UARTCR5_RDMAS, sport->port.membase + UARTCR5);
}
}
if (sport->lpuart_dma_tx_use) {
sport->dma_tx_in_progress = false;
dmaengine_terminate_sync(sport->dma_tx_chan);
}
if (sport->port.suspended && !irq_wake)
lpuart_disable_clks(sport);
return 0;
}
static int __maybe_unused lpuart_resume(struct device *dev)
{
struct lpuart_port *sport = dev_get_drvdata(dev);
bool irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq));
if (sport->port.suspended && !irq_wake)
lpuart_enable_clks(sport);
if (lpuart_is_32(sport))
lpuart32_setup_watermark_enable(sport);
else
lpuart_setup_watermark_enable(sport);
if (sport->lpuart_dma_rx_use) {
if (irq_wake) {
if (!lpuart_start_rx_dma(sport))
rx_dma_timer_init(sport);
else
sport->lpuart_dma_rx_use = false;
}
}
lpuart_tx_dma_startup(sport);
if (lpuart_is_32(sport))
lpuart32_configure(sport);
uart_resume_port(&lpuart_reg, &sport->port);
return 0;
}
static SIMPLE_DEV_PM_OPS(lpuart_pm_ops, lpuart_suspend, lpuart_resume);
static struct platform_driver lpuart_driver = {
.probe = lpuart_probe,
.remove = lpuart_remove,
.driver = {
.name = "fsl-lpuart",
.of_match_table = lpuart_dt_ids,
.pm = &lpuart_pm_ops,
},
};
static int __init lpuart_serial_init(void)
{
int ret = uart_register_driver(&lpuart_reg);
if (ret)
return ret;
ret = platform_driver_register(&lpuart_driver);
if (ret)
uart_unregister_driver(&lpuart_reg);
return ret;
}
static void __exit lpuart_serial_exit(void)
{
platform_driver_unregister(&lpuart_driver);
uart_unregister_driver(&lpuart_reg);
}
module_init(lpuart_serial_init);
module_exit(lpuart_serial_exit);
MODULE_DESCRIPTION("Freescale lpuart serial port driver");
MODULE_LICENSE("GPL v2");