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linuxdebug/drivers/spi/spi-zynq-qspi.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019 Xilinx, Inc.
*
* Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/workqueue.h>
#include <linux/spi/spi-mem.h>
/* Register offset definitions */
#define ZYNQ_QSPI_CONFIG_OFFSET 0x00 /* Configuration Register, RW */
#define ZYNQ_QSPI_STATUS_OFFSET 0x04 /* Interrupt Status Register, RO */
#define ZYNQ_QSPI_IEN_OFFSET 0x08 /* Interrupt Enable Register, WO */
#define ZYNQ_QSPI_IDIS_OFFSET 0x0C /* Interrupt Disable Reg, WO */
#define ZYNQ_QSPI_IMASK_OFFSET 0x10 /* Interrupt Enabled Mask Reg,RO */
#define ZYNQ_QSPI_ENABLE_OFFSET 0x14 /* Enable/Disable Register, RW */
#define ZYNQ_QSPI_DELAY_OFFSET 0x18 /* Delay Register, RW */
#define ZYNQ_QSPI_TXD_00_00_OFFSET 0x1C /* Transmit 4-byte inst, WO */
#define ZYNQ_QSPI_TXD_00_01_OFFSET 0x80 /* Transmit 1-byte inst, WO */
#define ZYNQ_QSPI_TXD_00_10_OFFSET 0x84 /* Transmit 2-byte inst, WO */
#define ZYNQ_QSPI_TXD_00_11_OFFSET 0x88 /* Transmit 3-byte inst, WO */
#define ZYNQ_QSPI_RXD_OFFSET 0x20 /* Data Receive Register, RO */
#define ZYNQ_QSPI_SIC_OFFSET 0x24 /* Slave Idle Count Register, RW */
#define ZYNQ_QSPI_TX_THRESH_OFFSET 0x28 /* TX FIFO Watermark Reg, RW */
#define ZYNQ_QSPI_RX_THRESH_OFFSET 0x2C /* RX FIFO Watermark Reg, RW */
#define ZYNQ_QSPI_GPIO_OFFSET 0x30 /* GPIO Register, RW */
#define ZYNQ_QSPI_LINEAR_CFG_OFFSET 0xA0 /* Linear Adapter Config Ref, RW */
#define ZYNQ_QSPI_MOD_ID_OFFSET 0xFC /* Module ID Register, RO */
/*
* QSPI Configuration Register bit Masks
*
* This register contains various control bits that effect the operation
* of the QSPI controller
*/
#define ZYNQ_QSPI_CONFIG_IFMODE_MASK BIT(31) /* Flash Memory Interface */
#define ZYNQ_QSPI_CONFIG_MANSRT_MASK BIT(16) /* Manual TX Start */
#define ZYNQ_QSPI_CONFIG_MANSRTEN_MASK BIT(15) /* Enable Manual TX Mode */
#define ZYNQ_QSPI_CONFIG_SSFORCE_MASK BIT(14) /* Manual Chip Select */
#define ZYNQ_QSPI_CONFIG_BDRATE_MASK GENMASK(5, 3) /* Baud Rate Mask */
#define ZYNQ_QSPI_CONFIG_CPHA_MASK BIT(2) /* Clock Phase Control */
#define ZYNQ_QSPI_CONFIG_CPOL_MASK BIT(1) /* Clock Polarity Control */
#define ZYNQ_QSPI_CONFIG_FWIDTH_MASK GENMASK(7, 6) /* FIFO width */
#define ZYNQ_QSPI_CONFIG_MSTREN_MASK BIT(0) /* Master Mode */
/*
* QSPI Configuration Register - Baud rate and slave select
*
* These are the values used in the calculation of baud rate divisor and
* setting the slave select.
*/
#define ZYNQ_QSPI_CONFIG_BAUD_DIV_MAX GENMASK(2, 0) /* Baud rate maximum */
#define ZYNQ_QSPI_CONFIG_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift */
#define ZYNQ_QSPI_CONFIG_PCS BIT(10) /* Peripheral Chip Select */
/*
* QSPI Interrupt Registers bit Masks
*
* All the four interrupt registers (Status/Mask/Enable/Disable) have the same
* bit definitions.
*/
#define ZYNQ_QSPI_IXR_RX_OVERFLOW_MASK BIT(0) /* QSPI RX FIFO Overflow */
#define ZYNQ_QSPI_IXR_TXNFULL_MASK BIT(2) /* QSPI TX FIFO Overflow */
#define ZYNQ_QSPI_IXR_TXFULL_MASK BIT(3) /* QSPI TX FIFO is full */
#define ZYNQ_QSPI_IXR_RXNEMTY_MASK BIT(4) /* QSPI RX FIFO Not Empty */
#define ZYNQ_QSPI_IXR_RXF_FULL_MASK BIT(5) /* QSPI RX FIFO is full */
#define ZYNQ_QSPI_IXR_TXF_UNDRFLOW_MASK BIT(6) /* QSPI TX FIFO Underflow */
#define ZYNQ_QSPI_IXR_ALL_MASK (ZYNQ_QSPI_IXR_RX_OVERFLOW_MASK | \
ZYNQ_QSPI_IXR_TXNFULL_MASK | \
ZYNQ_QSPI_IXR_TXFULL_MASK | \
ZYNQ_QSPI_IXR_RXNEMTY_MASK | \
ZYNQ_QSPI_IXR_RXF_FULL_MASK | \
ZYNQ_QSPI_IXR_TXF_UNDRFLOW_MASK)
#define ZYNQ_QSPI_IXR_RXTX_MASK (ZYNQ_QSPI_IXR_TXNFULL_MASK | \
ZYNQ_QSPI_IXR_RXNEMTY_MASK)
/*
* QSPI Enable Register bit Masks
*
* This register is used to enable or disable the QSPI controller
*/
#define ZYNQ_QSPI_ENABLE_ENABLE_MASK BIT(0) /* QSPI Enable Bit Mask */
/*
* QSPI Linear Configuration Register
*
* It is named Linear Configuration but it controls other modes when not in
* linear mode also.
*/
#define ZYNQ_QSPI_LCFG_TWO_MEM BIT(30) /* LQSPI Two memories */
#define ZYNQ_QSPI_LCFG_SEP_BUS BIT(29) /* LQSPI Separate bus */
#define ZYNQ_QSPI_LCFG_U_PAGE BIT(28) /* LQSPI Upper Page */
#define ZYNQ_QSPI_LCFG_DUMMY_SHIFT 8
#define ZYNQ_QSPI_FAST_READ_QOUT_CODE 0x6B /* read instruction code */
#define ZYNQ_QSPI_FIFO_DEPTH 63 /* FIFO depth in words */
#define ZYNQ_QSPI_RX_THRESHOLD 32 /* Rx FIFO threshold level */
#define ZYNQ_QSPI_TX_THRESHOLD 1 /* Tx FIFO threshold level */
/*
* The modebits configurable by the driver to make the SPI support different
* data formats
*/
#define ZYNQ_QSPI_MODEBITS (SPI_CPOL | SPI_CPHA)
/* Maximum number of chip selects */
#define ZYNQ_QSPI_MAX_NUM_CS 2
/**
* struct zynq_qspi - Defines qspi driver instance
* @dev: Pointer to the this device's information
* @regs: Virtual address of the QSPI controller registers
* @refclk: Pointer to the peripheral clock
* @pclk: Pointer to the APB clock
* @irq: IRQ number
* @txbuf: Pointer to the TX buffer
* @rxbuf: Pointer to the RX buffer
* @tx_bytes: Number of bytes left to transfer
* @rx_bytes: Number of bytes left to receive
* @data_completion: completion structure
*/
struct zynq_qspi {
struct device *dev;
void __iomem *regs;
struct clk *refclk;
struct clk *pclk;
int irq;
u8 *txbuf;
u8 *rxbuf;
int tx_bytes;
int rx_bytes;
struct completion data_completion;
};
/*
* Inline functions for the QSPI controller read/write
*/
static inline u32 zynq_qspi_read(struct zynq_qspi *xqspi, u32 offset)
{
return readl_relaxed(xqspi->regs + offset);
}
static inline void zynq_qspi_write(struct zynq_qspi *xqspi, u32 offset,
u32 val)
{
writel_relaxed(val, xqspi->regs + offset);
}
/**
* zynq_qspi_init_hw - Initialize the hardware
* @xqspi: Pointer to the zynq_qspi structure
* @num_cs: Number of connected CS (to enable dual memories if needed)
*
* The default settings of the QSPI controller's configurable parameters on
* reset are
* - Master mode
* - Baud rate divisor is set to 2
* - Tx threshold set to 1l Rx threshold set to 32
* - Flash memory interface mode enabled
* - Size of the word to be transferred as 8 bit
* This function performs the following actions
* - Disable and clear all the interrupts
* - Enable manual slave select
* - Enable manual start
* - Deselect all the chip select lines
* - Set the size of the word to be transferred as 32 bit
* - Set the little endian mode of TX FIFO and
* - Enable the QSPI controller
*/
static void zynq_qspi_init_hw(struct zynq_qspi *xqspi, unsigned int num_cs)
{
u32 config_reg;
zynq_qspi_write(xqspi, ZYNQ_QSPI_ENABLE_OFFSET, 0);
zynq_qspi_write(xqspi, ZYNQ_QSPI_IDIS_OFFSET, ZYNQ_QSPI_IXR_ALL_MASK);
/* Disable linear mode as the boot loader may have used it */
config_reg = 0;
/* At the same time, enable dual mode if more than 1 CS is available */
if (num_cs > 1)
config_reg |= ZYNQ_QSPI_LCFG_TWO_MEM;
zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, config_reg);
/* Clear the RX FIFO */
while (zynq_qspi_read(xqspi, ZYNQ_QSPI_STATUS_OFFSET) &
ZYNQ_QSPI_IXR_RXNEMTY_MASK)
zynq_qspi_read(xqspi, ZYNQ_QSPI_RXD_OFFSET);
zynq_qspi_write(xqspi, ZYNQ_QSPI_STATUS_OFFSET, ZYNQ_QSPI_IXR_ALL_MASK);
config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET);
config_reg &= ~(ZYNQ_QSPI_CONFIG_MSTREN_MASK |
ZYNQ_QSPI_CONFIG_CPOL_MASK |
ZYNQ_QSPI_CONFIG_CPHA_MASK |
ZYNQ_QSPI_CONFIG_BDRATE_MASK |
ZYNQ_QSPI_CONFIG_SSFORCE_MASK |
ZYNQ_QSPI_CONFIG_MANSRTEN_MASK |
ZYNQ_QSPI_CONFIG_MANSRT_MASK);
config_reg |= (ZYNQ_QSPI_CONFIG_MSTREN_MASK |
ZYNQ_QSPI_CONFIG_SSFORCE_MASK |
ZYNQ_QSPI_CONFIG_FWIDTH_MASK |
ZYNQ_QSPI_CONFIG_IFMODE_MASK);
zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg);
zynq_qspi_write(xqspi, ZYNQ_QSPI_RX_THRESH_OFFSET,
ZYNQ_QSPI_RX_THRESHOLD);
zynq_qspi_write(xqspi, ZYNQ_QSPI_TX_THRESH_OFFSET,
ZYNQ_QSPI_TX_THRESHOLD);
zynq_qspi_write(xqspi, ZYNQ_QSPI_ENABLE_OFFSET,
ZYNQ_QSPI_ENABLE_ENABLE_MASK);
}
static bool zynq_qspi_supports_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
if (!spi_mem_default_supports_op(mem, op))
return false;
/*
* The number of address bytes should be equal to or less than 3 bytes.
*/
if (op->addr.nbytes > 3)
return false;
return true;
}
/**
* zynq_qspi_rxfifo_op - Read 1..4 bytes from RxFIFO to RX buffer
* @xqspi: Pointer to the zynq_qspi structure
* @size: Number of bytes to be read (1..4)
*/
static void zynq_qspi_rxfifo_op(struct zynq_qspi *xqspi, unsigned int size)
{
u32 data;
data = zynq_qspi_read(xqspi, ZYNQ_QSPI_RXD_OFFSET);
if (xqspi->rxbuf) {
memcpy(xqspi->rxbuf, ((u8 *)&data) + 4 - size, size);
xqspi->rxbuf += size;
}
xqspi->rx_bytes -= size;
if (xqspi->rx_bytes < 0)
xqspi->rx_bytes = 0;
}
/**
* zynq_qspi_txfifo_op - Write 1..4 bytes from TX buffer to TxFIFO
* @xqspi: Pointer to the zynq_qspi structure
* @size: Number of bytes to be written (1..4)
*/
static void zynq_qspi_txfifo_op(struct zynq_qspi *xqspi, unsigned int size)
{
static const unsigned int offset[4] = {
ZYNQ_QSPI_TXD_00_01_OFFSET, ZYNQ_QSPI_TXD_00_10_OFFSET,
ZYNQ_QSPI_TXD_00_11_OFFSET, ZYNQ_QSPI_TXD_00_00_OFFSET };
u32 data;
if (xqspi->txbuf) {
data = 0xffffffff;
memcpy(&data, xqspi->txbuf, size);
xqspi->txbuf += size;
} else {
data = 0;
}
xqspi->tx_bytes -= size;
zynq_qspi_write(xqspi, offset[size - 1], data);
}
/**
* zynq_qspi_chipselect - Select or deselect the chip select line
* @spi: Pointer to the spi_device structure
* @assert: 1 for select or 0 for deselect the chip select line
*/
static void zynq_qspi_chipselect(struct spi_device *spi, bool assert)
{
struct spi_controller *ctlr = spi->master;
struct zynq_qspi *xqspi = spi_controller_get_devdata(ctlr);
u32 config_reg;
/* Select the lower (CS0) or upper (CS1) memory */
if (ctlr->num_chipselect > 1) {
config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET);
if (!spi->chip_select)
config_reg &= ~ZYNQ_QSPI_LCFG_U_PAGE;
else
config_reg |= ZYNQ_QSPI_LCFG_U_PAGE;
zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, config_reg);
}
/* Ground the line to assert the CS */
config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET);
if (assert)
config_reg &= ~ZYNQ_QSPI_CONFIG_PCS;
else
config_reg |= ZYNQ_QSPI_CONFIG_PCS;
zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg);
}
/**
* zynq_qspi_config_op - Configure QSPI controller for specified transfer
* @xqspi: Pointer to the zynq_qspi structure
* @spi: Pointer to the spi_device structure
*
* Sets the operational mode of QSPI controller for the next QSPI transfer and
* sets the requested clock frequency.
*
* Return: 0 on success and -EINVAL on invalid input parameter
*
* Note: If the requested frequency is not an exact match with what can be
* obtained using the prescalar value, the driver sets the clock frequency which
* is lower than the requested frequency (maximum lower) for the transfer. If
* the requested frequency is higher or lower than that is supported by the QSPI
* controller the driver will set the highest or lowest frequency supported by
* controller.
*/
static int zynq_qspi_config_op(struct zynq_qspi *xqspi, struct spi_device *spi)
{
u32 config_reg, baud_rate_val = 0;
/*
* Set the clock frequency
* The baud rate divisor is not a direct mapping to the value written
* into the configuration register (config_reg[5:3])
* i.e. 000 - divide by 2
* 001 - divide by 4
* ----------------
* 111 - divide by 256
*/
while ((baud_rate_val < ZYNQ_QSPI_CONFIG_BAUD_DIV_MAX) &&
(clk_get_rate(xqspi->refclk) / (2 << baud_rate_val)) >
spi->max_speed_hz)
baud_rate_val++;
config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET);
/* Set the QSPI clock phase and clock polarity */
config_reg &= (~ZYNQ_QSPI_CONFIG_CPHA_MASK) &
(~ZYNQ_QSPI_CONFIG_CPOL_MASK);
if (spi->mode & SPI_CPHA)
config_reg |= ZYNQ_QSPI_CONFIG_CPHA_MASK;
if (spi->mode & SPI_CPOL)
config_reg |= ZYNQ_QSPI_CONFIG_CPOL_MASK;
config_reg &= ~ZYNQ_QSPI_CONFIG_BDRATE_MASK;
config_reg |= (baud_rate_val << ZYNQ_QSPI_CONFIG_BAUD_DIV_SHIFT);
zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg);
return 0;
}
/**
* zynq_qspi_setup_op - Configure the QSPI controller
* @spi: Pointer to the spi_device structure
*
* Sets the operational mode of QSPI controller for the next QSPI transfer, baud
* rate and divisor value to setup the requested qspi clock.
*
* Return: 0 on success and error value on failure
*/
static int zynq_qspi_setup_op(struct spi_device *spi)
{
struct spi_controller *ctlr = spi->master;
struct zynq_qspi *qspi = spi_controller_get_devdata(ctlr);
if (ctlr->busy)
return -EBUSY;
clk_enable(qspi->refclk);
clk_enable(qspi->pclk);
zynq_qspi_write(qspi, ZYNQ_QSPI_ENABLE_OFFSET,
ZYNQ_QSPI_ENABLE_ENABLE_MASK);
return 0;
}
/**
* zynq_qspi_write_op - Fills the TX FIFO with as many bytes as possible
* @xqspi: Pointer to the zynq_qspi structure
* @txcount: Maximum number of words to write
* @txempty: Indicates that TxFIFO is empty
*/
static void zynq_qspi_write_op(struct zynq_qspi *xqspi, int txcount,
bool txempty)
{
int count, len, k;
len = xqspi->tx_bytes;
if (len && len < 4) {
/*
* We must empty the TxFIFO between accesses to TXD0,
* TXD1, TXD2, TXD3.
*/
if (txempty)
zynq_qspi_txfifo_op(xqspi, len);
return;
}
count = len / 4;
if (count > txcount)
count = txcount;
if (xqspi->txbuf) {
iowrite32_rep(xqspi->regs + ZYNQ_QSPI_TXD_00_00_OFFSET,
xqspi->txbuf, count);
xqspi->txbuf += count * 4;
} else {
for (k = 0; k < count; k++)
writel_relaxed(0, xqspi->regs +
ZYNQ_QSPI_TXD_00_00_OFFSET);
}
xqspi->tx_bytes -= count * 4;
}
/**
* zynq_qspi_read_op - Drains the RX FIFO by as many bytes as possible
* @xqspi: Pointer to the zynq_qspi structure
* @rxcount: Maximum number of words to read
*/
static void zynq_qspi_read_op(struct zynq_qspi *xqspi, int rxcount)
{
int count, len, k;
len = xqspi->rx_bytes - xqspi->tx_bytes;
count = len / 4;
if (count > rxcount)
count = rxcount;
if (xqspi->rxbuf) {
ioread32_rep(xqspi->regs + ZYNQ_QSPI_RXD_OFFSET,
xqspi->rxbuf, count);
xqspi->rxbuf += count * 4;
} else {
for (k = 0; k < count; k++)
readl_relaxed(xqspi->regs + ZYNQ_QSPI_RXD_OFFSET);
}
xqspi->rx_bytes -= count * 4;
len -= count * 4;
if (len && len < 4 && count < rxcount)
zynq_qspi_rxfifo_op(xqspi, len);
}
/**
* zynq_qspi_irq - Interrupt service routine of the QSPI controller
* @irq: IRQ number
* @dev_id: Pointer to the xqspi structure
*
* This function handles TX empty only.
* On TX empty interrupt this function reads the received data from RX FIFO and
* fills the TX FIFO if there is any data remaining to be transferred.
*
* Return: IRQ_HANDLED when interrupt is handled; IRQ_NONE otherwise.
*/
static irqreturn_t zynq_qspi_irq(int irq, void *dev_id)
{
u32 intr_status;
bool txempty;
struct zynq_qspi *xqspi = (struct zynq_qspi *)dev_id;
intr_status = zynq_qspi_read(xqspi, ZYNQ_QSPI_STATUS_OFFSET);
zynq_qspi_write(xqspi, ZYNQ_QSPI_STATUS_OFFSET, intr_status);
if ((intr_status & ZYNQ_QSPI_IXR_TXNFULL_MASK) ||
(intr_status & ZYNQ_QSPI_IXR_RXNEMTY_MASK)) {
/*
* This bit is set when Tx FIFO has < THRESHOLD entries.
* We have the THRESHOLD value set to 1,
* so this bit indicates Tx FIFO is empty.
*/
txempty = !!(intr_status & ZYNQ_QSPI_IXR_TXNFULL_MASK);
/* Read out the data from the RX FIFO */
zynq_qspi_read_op(xqspi, ZYNQ_QSPI_RX_THRESHOLD);
if (xqspi->tx_bytes) {
/* There is more data to send */
zynq_qspi_write_op(xqspi, ZYNQ_QSPI_RX_THRESHOLD,
txempty);
} else {
/*
* If transfer and receive is completed then only send
* complete signal.
*/
if (!xqspi->rx_bytes) {
zynq_qspi_write(xqspi,
ZYNQ_QSPI_IDIS_OFFSET,
ZYNQ_QSPI_IXR_RXTX_MASK);
complete(&xqspi->data_completion);
}
}
return IRQ_HANDLED;
}
return IRQ_NONE;
}
/**
* zynq_qspi_exec_mem_op() - Initiates the QSPI transfer
* @mem: the SPI memory
* @op: the memory operation to execute
*
* Executes a memory operation.
*
* This function first selects the chip and starts the memory operation.
*
* Return: 0 in case of success, a negative error code otherwise.
*/
static int zynq_qspi_exec_mem_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
struct zynq_qspi *xqspi = spi_controller_get_devdata(mem->spi->master);
int err = 0, i;
u8 *tmpbuf;
dev_dbg(xqspi->dev, "cmd:%#x mode:%d.%d.%d.%d\n",
op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
op->dummy.buswidth, op->data.buswidth);
zynq_qspi_chipselect(mem->spi, true);
zynq_qspi_config_op(xqspi, mem->spi);
if (op->cmd.opcode) {
reinit_completion(&xqspi->data_completion);
xqspi->txbuf = (u8 *)&op->cmd.opcode;
xqspi->rxbuf = NULL;
xqspi->tx_bytes = op->cmd.nbytes;
xqspi->rx_bytes = op->cmd.nbytes;
zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
ZYNQ_QSPI_IXR_RXTX_MASK);
if (!wait_for_completion_timeout(&xqspi->data_completion,
msecs_to_jiffies(1000)))
err = -ETIMEDOUT;
}
if (op->addr.nbytes) {
for (i = 0; i < op->addr.nbytes; i++) {
xqspi->txbuf[i] = op->addr.val >>
(8 * (op->addr.nbytes - i - 1));
}
reinit_completion(&xqspi->data_completion);
xqspi->rxbuf = NULL;
xqspi->tx_bytes = op->addr.nbytes;
xqspi->rx_bytes = op->addr.nbytes;
zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
ZYNQ_QSPI_IXR_RXTX_MASK);
if (!wait_for_completion_timeout(&xqspi->data_completion,
msecs_to_jiffies(1000)))
err = -ETIMEDOUT;
}
if (op->dummy.nbytes) {
tmpbuf = kzalloc(op->dummy.nbytes, GFP_KERNEL);
if (!tmpbuf)
return -ENOMEM;
memset(tmpbuf, 0xff, op->dummy.nbytes);
reinit_completion(&xqspi->data_completion);
xqspi->txbuf = tmpbuf;
xqspi->rxbuf = NULL;
xqspi->tx_bytes = op->dummy.nbytes;
xqspi->rx_bytes = op->dummy.nbytes;
zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
ZYNQ_QSPI_IXR_RXTX_MASK);
if (!wait_for_completion_timeout(&xqspi->data_completion,
msecs_to_jiffies(1000)))
err = -ETIMEDOUT;
kfree(tmpbuf);
}
if (op->data.nbytes) {
reinit_completion(&xqspi->data_completion);
if (op->data.dir == SPI_MEM_DATA_OUT) {
xqspi->txbuf = (u8 *)op->data.buf.out;
xqspi->tx_bytes = op->data.nbytes;
xqspi->rxbuf = NULL;
xqspi->rx_bytes = op->data.nbytes;
} else {
xqspi->txbuf = NULL;
xqspi->rxbuf = (u8 *)op->data.buf.in;
xqspi->rx_bytes = op->data.nbytes;
xqspi->tx_bytes = op->data.nbytes;
}
zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
ZYNQ_QSPI_IXR_RXTX_MASK);
if (!wait_for_completion_timeout(&xqspi->data_completion,
msecs_to_jiffies(1000)))
err = -ETIMEDOUT;
}
zynq_qspi_chipselect(mem->spi, false);
return err;
}
static const struct spi_controller_mem_ops zynq_qspi_mem_ops = {
.supports_op = zynq_qspi_supports_op,
.exec_op = zynq_qspi_exec_mem_op,
};
/**
* zynq_qspi_probe - Probe method for the QSPI driver
* @pdev: Pointer to the platform_device structure
*
* This function initializes the driver data structures and the hardware.
*
* Return: 0 on success and error value on failure
*/
static int zynq_qspi_probe(struct platform_device *pdev)
{
int ret = 0;
struct spi_controller *ctlr;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct zynq_qspi *xqspi;
u32 num_cs;
ctlr = spi_alloc_master(&pdev->dev, sizeof(*xqspi));
if (!ctlr)
return -ENOMEM;
xqspi = spi_controller_get_devdata(ctlr);
xqspi->dev = dev;
platform_set_drvdata(pdev, xqspi);
xqspi->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(xqspi->regs)) {
ret = PTR_ERR(xqspi->regs);
goto remove_master;
}
xqspi->pclk = devm_clk_get(&pdev->dev, "pclk");
if (IS_ERR(xqspi->pclk)) {
dev_err(&pdev->dev, "pclk clock not found.\n");
ret = PTR_ERR(xqspi->pclk);
goto remove_master;
}
init_completion(&xqspi->data_completion);
xqspi->refclk = devm_clk_get(&pdev->dev, "ref_clk");
if (IS_ERR(xqspi->refclk)) {
dev_err(&pdev->dev, "ref_clk clock not found.\n");
ret = PTR_ERR(xqspi->refclk);
goto remove_master;
}
ret = clk_prepare_enable(xqspi->pclk);
if (ret) {
dev_err(&pdev->dev, "Unable to enable APB clock.\n");
goto remove_master;
}
ret = clk_prepare_enable(xqspi->refclk);
if (ret) {
dev_err(&pdev->dev, "Unable to enable device clock.\n");
goto clk_dis_pclk;
}
xqspi->irq = platform_get_irq(pdev, 0);
if (xqspi->irq <= 0) {
ret = -ENXIO;
goto clk_dis_all;
}
ret = devm_request_irq(&pdev->dev, xqspi->irq, zynq_qspi_irq,
0, pdev->name, xqspi);
if (ret != 0) {
ret = -ENXIO;
dev_err(&pdev->dev, "request_irq failed\n");
goto clk_dis_all;
}
ret = of_property_read_u32(np, "num-cs",
&num_cs);
if (ret < 0) {
ctlr->num_chipselect = 1;
} else if (num_cs > ZYNQ_QSPI_MAX_NUM_CS) {
ret = -EINVAL;
dev_err(&pdev->dev, "only 2 chip selects are available\n");
goto clk_dis_all;
} else {
ctlr->num_chipselect = num_cs;
}
ctlr->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD |
SPI_TX_DUAL | SPI_TX_QUAD;
ctlr->mem_ops = &zynq_qspi_mem_ops;
ctlr->setup = zynq_qspi_setup_op;
ctlr->max_speed_hz = clk_get_rate(xqspi->refclk) / 2;
ctlr->dev.of_node = np;
/* QSPI controller initializations */
zynq_qspi_init_hw(xqspi, ctlr->num_chipselect);
ret = devm_spi_register_controller(&pdev->dev, ctlr);
if (ret) {
dev_err(&pdev->dev, "spi_register_master failed\n");
goto clk_dis_all;
}
return ret;
clk_dis_all:
clk_disable_unprepare(xqspi->refclk);
clk_dis_pclk:
clk_disable_unprepare(xqspi->pclk);
remove_master:
spi_controller_put(ctlr);
return ret;
}
/**
* zynq_qspi_remove - Remove method for the QSPI driver
* @pdev: Pointer to the platform_device structure
*
* This function is called if a device is physically removed from the system or
* if the driver module is being unloaded. It frees all resources allocated to
* the device.
*
* Return: 0 on success and error value on failure
*/
static int zynq_qspi_remove(struct platform_device *pdev)
{
struct zynq_qspi *xqspi = platform_get_drvdata(pdev);
zynq_qspi_write(xqspi, ZYNQ_QSPI_ENABLE_OFFSET, 0);
clk_disable_unprepare(xqspi->refclk);
clk_disable_unprepare(xqspi->pclk);
return 0;
}
static const struct of_device_id zynq_qspi_of_match[] = {
{ .compatible = "xlnx,zynq-qspi-1.0", },
{ /* end of table */ }
};
MODULE_DEVICE_TABLE(of, zynq_qspi_of_match);
/*
* zynq_qspi_driver - This structure defines the QSPI platform driver
*/
static struct platform_driver zynq_qspi_driver = {
.probe = zynq_qspi_probe,
.remove = zynq_qspi_remove,
.driver = {
.name = "zynq-qspi",
.of_match_table = zynq_qspi_of_match,
},
};
module_platform_driver(zynq_qspi_driver);
MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("Xilinx Zynq QSPI driver");
MODULE_LICENSE("GPL");
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