// SPDX-License-Identifier: GPL-2.0-only // Copyright (C) 2014 Broadcom Corporation #include #include #include #include #include #include #include #include #include #define IDM_CTRL_DIRECT_OFFSET 0x00 #define CFG_OFFSET 0x00 #define CFG_RESET_SHIFT 31 #define CFG_EN_SHIFT 30 #define CFG_SLAVE_ADDR_0_SHIFT 28 #define CFG_M_RETRY_CNT_SHIFT 16 #define CFG_M_RETRY_CNT_MASK 0x0f #define TIM_CFG_OFFSET 0x04 #define TIM_CFG_MODE_400_SHIFT 31 #define TIM_RAND_SLAVE_STRETCH_SHIFT 24 #define TIM_RAND_SLAVE_STRETCH_MASK 0x7f #define TIM_PERIODIC_SLAVE_STRETCH_SHIFT 16 #define TIM_PERIODIC_SLAVE_STRETCH_MASK 0x7f #define S_CFG_SMBUS_ADDR_OFFSET 0x08 #define S_CFG_EN_NIC_SMB_ADDR3_SHIFT 31 #define S_CFG_NIC_SMB_ADDR3_SHIFT 24 #define S_CFG_NIC_SMB_ADDR3_MASK 0x7f #define S_CFG_EN_NIC_SMB_ADDR2_SHIFT 23 #define S_CFG_NIC_SMB_ADDR2_SHIFT 16 #define S_CFG_NIC_SMB_ADDR2_MASK 0x7f #define S_CFG_EN_NIC_SMB_ADDR1_SHIFT 15 #define S_CFG_NIC_SMB_ADDR1_SHIFT 8 #define S_CFG_NIC_SMB_ADDR1_MASK 0x7f #define S_CFG_EN_NIC_SMB_ADDR0_SHIFT 7 #define S_CFG_NIC_SMB_ADDR0_SHIFT 0 #define S_CFG_NIC_SMB_ADDR0_MASK 0x7f #define M_FIFO_CTRL_OFFSET 0x0c #define M_FIFO_RX_FLUSH_SHIFT 31 #define M_FIFO_TX_FLUSH_SHIFT 30 #define M_FIFO_RX_CNT_SHIFT 16 #define M_FIFO_RX_CNT_MASK 0x7f #define M_FIFO_RX_THLD_SHIFT 8 #define M_FIFO_RX_THLD_MASK 0x3f #define S_FIFO_CTRL_OFFSET 0x10 #define S_FIFO_RX_FLUSH_SHIFT 31 #define S_FIFO_TX_FLUSH_SHIFT 30 #define S_FIFO_RX_CNT_SHIFT 16 #define S_FIFO_RX_CNT_MASK 0x7f #define S_FIFO_RX_THLD_SHIFT 8 #define S_FIFO_RX_THLD_MASK 0x3f #define M_CMD_OFFSET 0x30 #define M_CMD_START_BUSY_SHIFT 31 #define M_CMD_STATUS_SHIFT 25 #define M_CMD_STATUS_MASK 0x07 #define M_CMD_STATUS_SUCCESS 0x0 #define M_CMD_STATUS_LOST_ARB 0x1 #define M_CMD_STATUS_NACK_ADDR 0x2 #define M_CMD_STATUS_NACK_DATA 0x3 #define M_CMD_STATUS_TIMEOUT 0x4 #define M_CMD_STATUS_FIFO_UNDERRUN 0x5 #define M_CMD_STATUS_RX_FIFO_FULL 0x6 #define M_CMD_PROTOCOL_SHIFT 9 #define M_CMD_PROTOCOL_MASK 0xf #define M_CMD_PROTOCOL_QUICK 0x0 #define M_CMD_PROTOCOL_BLK_WR 0x7 #define M_CMD_PROTOCOL_BLK_RD 0x8 #define M_CMD_PROTOCOL_PROCESS 0xa #define M_CMD_PEC_SHIFT 8 #define M_CMD_RD_CNT_SHIFT 0 #define M_CMD_RD_CNT_MASK 0xff #define S_CMD_OFFSET 0x34 #define S_CMD_START_BUSY_SHIFT 31 #define S_CMD_STATUS_SHIFT 23 #define S_CMD_STATUS_MASK 0x07 #define S_CMD_STATUS_SUCCESS 0x0 #define S_CMD_STATUS_TIMEOUT 0x5 #define S_CMD_STATUS_MASTER_ABORT 0x7 #define IE_OFFSET 0x38 #define IE_M_RX_FIFO_FULL_SHIFT 31 #define IE_M_RX_THLD_SHIFT 30 #define IE_M_START_BUSY_SHIFT 28 #define IE_M_TX_UNDERRUN_SHIFT 27 #define IE_S_RX_FIFO_FULL_SHIFT 26 #define IE_S_RX_THLD_SHIFT 25 #define IE_S_RX_EVENT_SHIFT 24 #define IE_S_START_BUSY_SHIFT 23 #define IE_S_TX_UNDERRUN_SHIFT 22 #define IE_S_RD_EVENT_SHIFT 21 #define IS_OFFSET 0x3c #define IS_M_RX_FIFO_FULL_SHIFT 31 #define IS_M_RX_THLD_SHIFT 30 #define IS_M_START_BUSY_SHIFT 28 #define IS_M_TX_UNDERRUN_SHIFT 27 #define IS_S_RX_FIFO_FULL_SHIFT 26 #define IS_S_RX_THLD_SHIFT 25 #define IS_S_RX_EVENT_SHIFT 24 #define IS_S_START_BUSY_SHIFT 23 #define IS_S_TX_UNDERRUN_SHIFT 22 #define IS_S_RD_EVENT_SHIFT 21 #define M_TX_OFFSET 0x40 #define M_TX_WR_STATUS_SHIFT 31 #define M_TX_DATA_SHIFT 0 #define M_TX_DATA_MASK 0xff #define M_RX_OFFSET 0x44 #define M_RX_STATUS_SHIFT 30 #define M_RX_STATUS_MASK 0x03 #define M_RX_PEC_ERR_SHIFT 29 #define M_RX_DATA_SHIFT 0 #define M_RX_DATA_MASK 0xff #define S_TX_OFFSET 0x48 #define S_TX_WR_STATUS_SHIFT 31 #define S_TX_DATA_SHIFT 0 #define S_TX_DATA_MASK 0xff #define S_RX_OFFSET 0x4c #define S_RX_STATUS_SHIFT 30 #define S_RX_STATUS_MASK 0x03 #define S_RX_PEC_ERR_SHIFT 29 #define S_RX_DATA_SHIFT 0 #define S_RX_DATA_MASK 0xff #define I2C_TIMEOUT_MSEC 50000 #define M_TX_RX_FIFO_SIZE 64 #define M_RX_FIFO_MAX_THLD_VALUE (M_TX_RX_FIFO_SIZE - 1) #define M_RX_MAX_READ_LEN 255 #define M_RX_FIFO_THLD_VALUE 50 #define IE_M_ALL_INTERRUPT_SHIFT 27 #define IE_M_ALL_INTERRUPT_MASK 0x1e #define SLAVE_READ_WRITE_BIT_MASK 0x1 #define SLAVE_READ_WRITE_BIT_SHIFT 0x1 #define SLAVE_MAX_SIZE_TRANSACTION 64 #define SLAVE_CLOCK_STRETCH_TIME 25 #define IE_S_ALL_INTERRUPT_SHIFT 21 #define IE_S_ALL_INTERRUPT_MASK 0x3f /* * It takes ~18us to reading 10bytes of data, hence to keep tasklet * running for less time, max slave read per tasklet is set to 10 bytes. */ #define MAX_SLAVE_RX_PER_INT 10 enum i2c_slave_read_status { I2C_SLAVE_RX_FIFO_EMPTY = 0, I2C_SLAVE_RX_START, I2C_SLAVE_RX_DATA, I2C_SLAVE_RX_END, }; enum bus_speed_index { I2C_SPD_100K = 0, I2C_SPD_400K, }; enum bcm_iproc_i2c_type { IPROC_I2C, IPROC_I2C_NIC }; struct bcm_iproc_i2c_dev { struct device *device; enum bcm_iproc_i2c_type type; int irq; void __iomem *base; void __iomem *idm_base; u32 ape_addr_mask; /* lock for indirect access through IDM */ spinlock_t idm_lock; struct i2c_adapter adapter; unsigned int bus_speed; struct completion done; int xfer_is_done; struct i2c_msg *msg; struct i2c_client *slave; /* bytes that have been transferred */ unsigned int tx_bytes; /* bytes that have been read */ unsigned int rx_bytes; unsigned int thld_bytes; bool slave_rx_only; bool rx_start_rcvd; bool slave_read_complete; u32 tx_underrun; u32 slave_int_mask; struct tasklet_struct slave_rx_tasklet; }; /* tasklet to process slave rx data */ static void slave_rx_tasklet_fn(unsigned long); /* * Can be expanded in the future if more interrupt status bits are utilized */ #define ISR_MASK (BIT(IS_M_START_BUSY_SHIFT) | BIT(IS_M_TX_UNDERRUN_SHIFT)\ | BIT(IS_M_RX_THLD_SHIFT)) #define ISR_MASK_SLAVE (BIT(IS_S_START_BUSY_SHIFT)\ | BIT(IS_S_RX_EVENT_SHIFT) | BIT(IS_S_RD_EVENT_SHIFT)\ | BIT(IS_S_TX_UNDERRUN_SHIFT) | BIT(IS_S_RX_FIFO_FULL_SHIFT)\ | BIT(IS_S_RX_THLD_SHIFT)) static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave); static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave); static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c, bool enable); static inline u32 iproc_i2c_rd_reg(struct bcm_iproc_i2c_dev *iproc_i2c, u32 offset) { u32 val; unsigned long flags; if (iproc_i2c->idm_base) { spin_lock_irqsave(&iproc_i2c->idm_lock, flags); writel(iproc_i2c->ape_addr_mask, iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET); val = readl(iproc_i2c->base + offset); spin_unlock_irqrestore(&iproc_i2c->idm_lock, flags); } else { val = readl(iproc_i2c->base + offset); } return val; } static inline void iproc_i2c_wr_reg(struct bcm_iproc_i2c_dev *iproc_i2c, u32 offset, u32 val) { unsigned long flags; if (iproc_i2c->idm_base) { spin_lock_irqsave(&iproc_i2c->idm_lock, flags); writel(iproc_i2c->ape_addr_mask, iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET); writel(val, iproc_i2c->base + offset); spin_unlock_irqrestore(&iproc_i2c->idm_lock, flags); } else { writel(val, iproc_i2c->base + offset); } } static void bcm_iproc_i2c_slave_init( struct bcm_iproc_i2c_dev *iproc_i2c, bool need_reset) { u32 val; iproc_i2c->tx_underrun = 0; if (need_reset) { /* put controller in reset */ val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET); val |= BIT(CFG_RESET_SHIFT); iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val); /* wait 100 usec per spec */ udelay(100); /* bring controller out of reset */ val &= ~(BIT(CFG_RESET_SHIFT)); iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val); } /* flush TX/RX FIFOs */ val = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT)); iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val); /* Maximum slave stretch time */ val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET); val &= ~(TIM_RAND_SLAVE_STRETCH_MASK << TIM_RAND_SLAVE_STRETCH_SHIFT); val |= (SLAVE_CLOCK_STRETCH_TIME << TIM_RAND_SLAVE_STRETCH_SHIFT); iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val); /* Configure the slave address */ val = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET); val |= BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT); val &= ~(S_CFG_NIC_SMB_ADDR3_MASK << S_CFG_NIC_SMB_ADDR3_SHIFT); val |= (iproc_i2c->slave->addr << S_CFG_NIC_SMB_ADDR3_SHIFT); iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, val); /* clear all pending slave interrupts */ iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE); /* Enable interrupt register to indicate a valid byte in receive fifo */ val = BIT(IE_S_RX_EVENT_SHIFT); /* Enable interrupt register to indicate Slave Rx FIFO Full */ val |= BIT(IE_S_RX_FIFO_FULL_SHIFT); /* Enable interrupt register to indicate a Master read transaction */ val |= BIT(IE_S_RD_EVENT_SHIFT); /* Enable interrupt register for the Slave BUSY command */ val |= BIT(IE_S_START_BUSY_SHIFT); iproc_i2c->slave_int_mask = val; iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); } static void bcm_iproc_i2c_check_slave_status( struct bcm_iproc_i2c_dev *iproc_i2c) { u32 val; val = iproc_i2c_rd_reg(iproc_i2c, S_CMD_OFFSET); /* status is valid only when START_BUSY is cleared after it was set */ if (val & BIT(S_CMD_START_BUSY_SHIFT)) return; val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK; if (val == S_CMD_STATUS_TIMEOUT || val == S_CMD_STATUS_MASTER_ABORT) { dev_err(iproc_i2c->device, (val == S_CMD_STATUS_TIMEOUT) ? "slave random stretch time timeout\n" : "Master aborted read transaction\n"); /* re-initialize i2c for recovery */ bcm_iproc_i2c_enable_disable(iproc_i2c, false); bcm_iproc_i2c_slave_init(iproc_i2c, true); bcm_iproc_i2c_enable_disable(iproc_i2c, true); } } static void bcm_iproc_i2c_slave_read(struct bcm_iproc_i2c_dev *iproc_i2c) { u8 rx_data, rx_status; u32 rx_bytes = 0; u32 val; while (rx_bytes < MAX_SLAVE_RX_PER_INT) { val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET); rx_status = (val >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK; rx_data = ((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK); if (rx_status == I2C_SLAVE_RX_START) { /* Start of SMBUS Master write */ i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_WRITE_REQUESTED, &rx_data); iproc_i2c->rx_start_rcvd = true; iproc_i2c->slave_read_complete = false; } else if (rx_status == I2C_SLAVE_RX_DATA && iproc_i2c->rx_start_rcvd) { /* Middle of SMBUS Master write */ i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_WRITE_RECEIVED, &rx_data); } else if (rx_status == I2C_SLAVE_RX_END && iproc_i2c->rx_start_rcvd) { /* End of SMBUS Master write */ if (iproc_i2c->slave_rx_only) i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_WRITE_RECEIVED, &rx_data); i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &rx_data); } else if (rx_status == I2C_SLAVE_RX_FIFO_EMPTY) { iproc_i2c->rx_start_rcvd = false; iproc_i2c->slave_read_complete = true; break; } rx_bytes++; } } static void slave_rx_tasklet_fn(unsigned long data) { struct bcm_iproc_i2c_dev *iproc_i2c = (struct bcm_iproc_i2c_dev *)data; u32 int_clr; bcm_iproc_i2c_slave_read(iproc_i2c); /* clear pending IS_S_RX_EVENT_SHIFT interrupt */ int_clr = BIT(IS_S_RX_EVENT_SHIFT); if (!iproc_i2c->slave_rx_only && iproc_i2c->slave_read_complete) { /* * In case of single byte master-read request, * IS_S_TX_UNDERRUN_SHIFT event is generated before * IS_S_START_BUSY_SHIFT event. Hence start slave data send * from first IS_S_TX_UNDERRUN_SHIFT event. * * This means don't send any data from slave when * IS_S_RD_EVENT_SHIFT event is generated else it will increment * eeprom or other backend slave driver read pointer twice. */ iproc_i2c->tx_underrun = 0; iproc_i2c->slave_int_mask |= BIT(IE_S_TX_UNDERRUN_SHIFT); /* clear IS_S_RD_EVENT_SHIFT interrupt */ int_clr |= BIT(IS_S_RD_EVENT_SHIFT); } /* clear slave interrupt */ iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, int_clr); /* enable slave interrupts */ iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, iproc_i2c->slave_int_mask); } static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c, u32 status) { u32 val; u8 value; /* * Slave events in case of master-write, master-write-read and, * master-read * * Master-write : only IS_S_RX_EVENT_SHIFT event * Master-write-read: both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT * events * Master-read : both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT * events or only IS_S_RD_EVENT_SHIFT * * iproc has a slave rx fifo size of 64 bytes. Rx fifo full interrupt * (IS_S_RX_FIFO_FULL_SHIFT) will be generated when RX fifo becomes * full. This can happen if Master issues write requests of more than * 64 bytes. */ if (status & BIT(IS_S_RX_EVENT_SHIFT) || status & BIT(IS_S_RD_EVENT_SHIFT) || status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) { /* disable slave interrupts */ val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); val &= ~iproc_i2c->slave_int_mask; iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); if (status & BIT(IS_S_RD_EVENT_SHIFT)) /* Master-write-read request */ iproc_i2c->slave_rx_only = false; else /* Master-write request only */ iproc_i2c->slave_rx_only = true; /* schedule tasklet to read data later */ tasklet_schedule(&iproc_i2c->slave_rx_tasklet); /* * clear only IS_S_RX_EVENT_SHIFT and * IS_S_RX_FIFO_FULL_SHIFT interrupt. */ val = BIT(IS_S_RX_EVENT_SHIFT); if (status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) val |= BIT(IS_S_RX_FIFO_FULL_SHIFT); iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, val); } if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) { iproc_i2c->tx_underrun++; if (iproc_i2c->tx_underrun == 1) /* Start of SMBUS for Master Read */ i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_READ_REQUESTED, &value); else /* Master read other than start */ i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_READ_PROCESSED, &value); iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value); /* start transfer */ val = BIT(S_CMD_START_BUSY_SHIFT); iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val); /* clear interrupt */ iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, BIT(IS_S_TX_UNDERRUN_SHIFT)); } /* Stop received from master in case of master read transaction */ if (status & BIT(IS_S_START_BUSY_SHIFT)) { /* * Disable interrupt for TX FIFO becomes empty and * less than PKT_LENGTH bytes were output on the SMBUS */ iproc_i2c->slave_int_mask &= ~BIT(IE_S_TX_UNDERRUN_SHIFT); iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, iproc_i2c->slave_int_mask); /* End of SMBUS for Master Read */ val = BIT(S_TX_WR_STATUS_SHIFT); iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, val); val = BIT(S_CMD_START_BUSY_SHIFT); iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val); /* flush TX FIFOs */ val = iproc_i2c_rd_reg(iproc_i2c, S_FIFO_CTRL_OFFSET); val |= (BIT(S_FIFO_TX_FLUSH_SHIFT)); iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val); i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value); /* clear interrupt */ iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, BIT(IS_S_START_BUSY_SHIFT)); } /* check slave transmit status only if slave is transmitting */ if (!iproc_i2c->slave_rx_only) bcm_iproc_i2c_check_slave_status(iproc_i2c); return true; } static void bcm_iproc_i2c_read_valid_bytes(struct bcm_iproc_i2c_dev *iproc_i2c) { struct i2c_msg *msg = iproc_i2c->msg; uint32_t val; /* Read valid data from RX FIFO */ while (iproc_i2c->rx_bytes < msg->len) { val = iproc_i2c_rd_reg(iproc_i2c, M_RX_OFFSET); /* rx fifo empty */ if (!((val >> M_RX_STATUS_SHIFT) & M_RX_STATUS_MASK)) break; msg->buf[iproc_i2c->rx_bytes] = (val >> M_RX_DATA_SHIFT) & M_RX_DATA_MASK; iproc_i2c->rx_bytes++; } } static void bcm_iproc_i2c_send(struct bcm_iproc_i2c_dev *iproc_i2c) { struct i2c_msg *msg = iproc_i2c->msg; unsigned int tx_bytes = msg->len - iproc_i2c->tx_bytes; unsigned int i; u32 val; /* can only fill up to the FIFO size */ tx_bytes = min_t(unsigned int, tx_bytes, M_TX_RX_FIFO_SIZE); for (i = 0; i < tx_bytes; i++) { /* start from where we left over */ unsigned int idx = iproc_i2c->tx_bytes + i; val = msg->buf[idx]; /* mark the last byte */ if (idx == msg->len - 1) { val |= BIT(M_TX_WR_STATUS_SHIFT); if (iproc_i2c->irq) { u32 tmp; /* * Since this is the last byte, we should now * disable TX FIFO underrun interrupt */ tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); tmp &= ~BIT(IE_M_TX_UNDERRUN_SHIFT); iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, tmp); } } /* load data into TX FIFO */ iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val); } /* update number of transferred bytes */ iproc_i2c->tx_bytes += tx_bytes; } static void bcm_iproc_i2c_read(struct bcm_iproc_i2c_dev *iproc_i2c) { struct i2c_msg *msg = iproc_i2c->msg; u32 bytes_left, val; bcm_iproc_i2c_read_valid_bytes(iproc_i2c); bytes_left = msg->len - iproc_i2c->rx_bytes; if (bytes_left == 0) { if (iproc_i2c->irq) { /* finished reading all data, disable rx thld event */ val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); val &= ~BIT(IS_M_RX_THLD_SHIFT); iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); } } else if (bytes_left < iproc_i2c->thld_bytes) { /* set bytes left as threshold */ val = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET); val &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT); val |= (bytes_left << M_FIFO_RX_THLD_SHIFT); iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val); iproc_i2c->thld_bytes = bytes_left; } /* * bytes_left >= iproc_i2c->thld_bytes, * hence no need to change the THRESHOLD SET. * It will remain as iproc_i2c->thld_bytes itself */ } static void bcm_iproc_i2c_process_m_event(struct bcm_iproc_i2c_dev *iproc_i2c, u32 status) { /* TX FIFO is empty and we have more data to send */ if (status & BIT(IS_M_TX_UNDERRUN_SHIFT)) bcm_iproc_i2c_send(iproc_i2c); /* RX FIFO threshold is reached and data needs to be read out */ if (status & BIT(IS_M_RX_THLD_SHIFT)) bcm_iproc_i2c_read(iproc_i2c); /* transfer is done */ if (status & BIT(IS_M_START_BUSY_SHIFT)) { iproc_i2c->xfer_is_done = 1; if (iproc_i2c->irq) complete(&iproc_i2c->done); } } static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data) { struct bcm_iproc_i2c_dev *iproc_i2c = data; u32 slave_status; u32 status; bool ret; status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET); /* process only slave interrupt which are enabled */ slave_status = status & iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET) & ISR_MASK_SLAVE; if (slave_status) { ret = bcm_iproc_i2c_slave_isr(iproc_i2c, slave_status); if (ret) return IRQ_HANDLED; else return IRQ_NONE; } status &= ISR_MASK; if (!status) return IRQ_NONE; /* process all master based events */ bcm_iproc_i2c_process_m_event(iproc_i2c, status); iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status); return IRQ_HANDLED; } static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c) { u32 val; /* put controller in reset */ val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET); val |= BIT(CFG_RESET_SHIFT); val &= ~(BIT(CFG_EN_SHIFT)); iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val); /* wait 100 usec per spec */ udelay(100); /* bring controller out of reset */ val &= ~(BIT(CFG_RESET_SHIFT)); iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val); /* flush TX/RX FIFOs and set RX FIFO threshold to zero */ val = (BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT)); iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val); /* disable all interrupts */ val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); val &= ~(IE_M_ALL_INTERRUPT_MASK << IE_M_ALL_INTERRUPT_SHIFT); iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); /* clear all pending interrupts */ iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, 0xffffffff); return 0; } static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c, bool enable) { u32 val; val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET); if (enable) val |= BIT(CFG_EN_SHIFT); else val &= ~BIT(CFG_EN_SHIFT); iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val); } static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c, struct i2c_msg *msg) { u32 val; val = iproc_i2c_rd_reg(iproc_i2c, M_CMD_OFFSET); val = (val >> M_CMD_STATUS_SHIFT) & M_CMD_STATUS_MASK; switch (val) { case M_CMD_STATUS_SUCCESS: return 0; case M_CMD_STATUS_LOST_ARB: dev_dbg(iproc_i2c->device, "lost bus arbitration\n"); return -EAGAIN; case M_CMD_STATUS_NACK_ADDR: dev_dbg(iproc_i2c->device, "NAK addr:0x%02x\n", msg->addr); return -ENXIO; case M_CMD_STATUS_NACK_DATA: dev_dbg(iproc_i2c->device, "NAK data\n"); return -ENXIO; case M_CMD_STATUS_TIMEOUT: dev_dbg(iproc_i2c->device, "bus timeout\n"); return -ETIMEDOUT; case M_CMD_STATUS_FIFO_UNDERRUN: dev_dbg(iproc_i2c->device, "FIFO under-run\n"); return -ENXIO; case M_CMD_STATUS_RX_FIFO_FULL: dev_dbg(iproc_i2c->device, "RX FIFO full\n"); return -ETIMEDOUT; default: dev_dbg(iproc_i2c->device, "unknown error code=%d\n", val); /* re-initialize i2c for recovery */ bcm_iproc_i2c_enable_disable(iproc_i2c, false); bcm_iproc_i2c_init(iproc_i2c); bcm_iproc_i2c_enable_disable(iproc_i2c, true); return -EIO; } } static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c, struct i2c_msg *msg, u32 cmd) { unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT_MSEC); u32 val, status; int ret; iproc_i2c_wr_reg(iproc_i2c, M_CMD_OFFSET, cmd); if (iproc_i2c->irq) { time_left = wait_for_completion_timeout(&iproc_i2c->done, time_left); /* disable all interrupts */ iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0); /* read it back to flush the write */ iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); /* make sure the interrupt handler isn't running */ synchronize_irq(iproc_i2c->irq); } else { /* polling mode */ unsigned long timeout = jiffies + time_left; do { status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET) & ISR_MASK; bcm_iproc_i2c_process_m_event(iproc_i2c, status); iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status); if (time_after(jiffies, timeout)) { time_left = 0; break; } cpu_relax(); cond_resched(); } while (!iproc_i2c->xfer_is_done); } if (!time_left && !iproc_i2c->xfer_is_done) { dev_err(iproc_i2c->device, "transaction timed out\n"); /* flush both TX/RX FIFOs */ val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT); iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val); return -ETIMEDOUT; } ret = bcm_iproc_i2c_check_status(iproc_i2c, msg); if (ret) { /* flush both TX/RX FIFOs */ val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT); iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val); return ret; } return 0; } /* * If 'process_call' is true, then this is a multi-msg transfer that requires * a repeated start between the messages. * More specifically, it must be a write (reg) followed by a read (data). * The i2c quirks are set to enforce this rule. */ static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c, struct i2c_msg *msgs, bool process_call) { int i; u8 addr; u32 val, tmp, val_intr_en; unsigned int tx_bytes; struct i2c_msg *msg = &msgs[0]; /* check if bus is busy */ if (!!(iproc_i2c_rd_reg(iproc_i2c, M_CMD_OFFSET) & BIT(M_CMD_START_BUSY_SHIFT))) { dev_warn(iproc_i2c->device, "bus is busy\n"); return -EBUSY; } iproc_i2c->msg = msg; /* format and load slave address into the TX FIFO */ addr = i2c_8bit_addr_from_msg(msg); iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, addr); /* * For a write transaction, load data into the TX FIFO. Only allow * loading up to TX FIFO size - 1 bytes of data since the first byte * has been used up by the slave address */ tx_bytes = min_t(unsigned int, msg->len, M_TX_RX_FIFO_SIZE - 1); if (!(msg->flags & I2C_M_RD)) { for (i = 0; i < tx_bytes; i++) { val = msg->buf[i]; /* mark the last byte */ if (!process_call && (i == msg->len - 1)) val |= BIT(M_TX_WR_STATUS_SHIFT); iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val); } iproc_i2c->tx_bytes = tx_bytes; } /* Process the read message if this is process call */ if (process_call) { msg++; iproc_i2c->msg = msg; /* point to second msg */ /* * The last byte to be sent out should be a slave * address with read operation */ addr = i2c_8bit_addr_from_msg(msg); /* mark it the last byte out */ val = addr | BIT(M_TX_WR_STATUS_SHIFT); iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val); } /* mark as incomplete before starting the transaction */ if (iproc_i2c->irq) reinit_completion(&iproc_i2c->done); iproc_i2c->xfer_is_done = 0; /* * Enable the "start busy" interrupt, which will be triggered after the * transaction is done, i.e., the internal start_busy bit, transitions * from 1 to 0. */ val_intr_en = BIT(IE_M_START_BUSY_SHIFT); /* * If TX data size is larger than the TX FIFO, need to enable TX * underrun interrupt, which will be triggerred when the TX FIFO is * empty. When that happens we can then pump more data into the FIFO */ if (!process_call && !(msg->flags & I2C_M_RD) && msg->len > iproc_i2c->tx_bytes) val_intr_en |= BIT(IE_M_TX_UNDERRUN_SHIFT); /* * Now we can activate the transfer. For a read operation, specify the * number of bytes to read */ val = BIT(M_CMD_START_BUSY_SHIFT); if (msg->len == 0) { /* SMBUS QUICK Command (Read/Write) */ val |= (M_CMD_PROTOCOL_QUICK << M_CMD_PROTOCOL_SHIFT); } else if (msg->flags & I2C_M_RD) { u32 protocol; iproc_i2c->rx_bytes = 0; if (msg->len > M_RX_FIFO_MAX_THLD_VALUE) iproc_i2c->thld_bytes = M_RX_FIFO_THLD_VALUE; else iproc_i2c->thld_bytes = msg->len; /* set threshold value */ tmp = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET); tmp &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT); tmp |= iproc_i2c->thld_bytes << M_FIFO_RX_THLD_SHIFT; iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, tmp); /* enable the RX threshold interrupt */ val_intr_en |= BIT(IE_M_RX_THLD_SHIFT); protocol = process_call ? M_CMD_PROTOCOL_PROCESS : M_CMD_PROTOCOL_BLK_RD; val |= (protocol << M_CMD_PROTOCOL_SHIFT) | (msg->len << M_CMD_RD_CNT_SHIFT); } else { val |= (M_CMD_PROTOCOL_BLK_WR << M_CMD_PROTOCOL_SHIFT); } if (iproc_i2c->irq) iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val_intr_en); return bcm_iproc_i2c_xfer_wait(iproc_i2c, msg, val); } static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg msgs[], int num) { struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adapter); bool process_call = false; int ret; if (num == 2) { /* Repeated start, use process call */ process_call = true; if (msgs[1].flags & I2C_M_NOSTART) { dev_err(iproc_i2c->device, "Invalid repeated start\n"); return -EOPNOTSUPP; } } ret = bcm_iproc_i2c_xfer_internal(iproc_i2c, msgs, process_call); if (ret) { dev_dbg(iproc_i2c->device, "xfer failed\n"); return ret; } return num; } static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap) { u32 val; val = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; if (adap->algo->reg_slave) val |= I2C_FUNC_SLAVE; return val; } static struct i2c_algorithm bcm_iproc_algo = { .master_xfer = bcm_iproc_i2c_xfer, .functionality = bcm_iproc_i2c_functionality, .reg_slave = bcm_iproc_i2c_reg_slave, .unreg_slave = bcm_iproc_i2c_unreg_slave, }; static const struct i2c_adapter_quirks bcm_iproc_i2c_quirks = { .flags = I2C_AQ_COMB_WRITE_THEN_READ, .max_comb_1st_msg_len = M_TX_RX_FIFO_SIZE, .max_read_len = M_RX_MAX_READ_LEN, }; static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c) { unsigned int bus_speed; u32 val; int ret = of_property_read_u32(iproc_i2c->device->of_node, "clock-frequency", &bus_speed); if (ret < 0) { dev_info(iproc_i2c->device, "unable to interpret clock-frequency DT property\n"); bus_speed = I2C_MAX_STANDARD_MODE_FREQ; } if (bus_speed < I2C_MAX_STANDARD_MODE_FREQ) { dev_err(iproc_i2c->device, "%d Hz bus speed not supported\n", bus_speed); dev_err(iproc_i2c->device, "valid speeds are 100khz and 400khz\n"); return -EINVAL; } else if (bus_speed < I2C_MAX_FAST_MODE_FREQ) { bus_speed = I2C_MAX_STANDARD_MODE_FREQ; } else { bus_speed = I2C_MAX_FAST_MODE_FREQ; } iproc_i2c->bus_speed = bus_speed; val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET); val &= ~BIT(TIM_CFG_MODE_400_SHIFT); val |= (bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT; iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val); dev_info(iproc_i2c->device, "bus set to %u Hz\n", bus_speed); return 0; } static int bcm_iproc_i2c_probe(struct platform_device *pdev) { int irq, ret = 0; struct bcm_iproc_i2c_dev *iproc_i2c; struct i2c_adapter *adap; struct resource *res; iproc_i2c = devm_kzalloc(&pdev->dev, sizeof(*iproc_i2c), GFP_KERNEL); if (!iproc_i2c) return -ENOMEM; platform_set_drvdata(pdev, iproc_i2c); iproc_i2c->device = &pdev->dev; iproc_i2c->type = (enum bcm_iproc_i2c_type)of_device_get_match_data(&pdev->dev); init_completion(&iproc_i2c->done); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); iproc_i2c->base = devm_ioremap_resource(iproc_i2c->device, res); if (IS_ERR(iproc_i2c->base)) return PTR_ERR(iproc_i2c->base); if (iproc_i2c->type == IPROC_I2C_NIC) { res = platform_get_resource(pdev, IORESOURCE_MEM, 1); iproc_i2c->idm_base = devm_ioremap_resource(iproc_i2c->device, res); if (IS_ERR(iproc_i2c->idm_base)) return PTR_ERR(iproc_i2c->idm_base); ret = of_property_read_u32(iproc_i2c->device->of_node, "brcm,ape-hsls-addr-mask", &iproc_i2c->ape_addr_mask); if (ret < 0) { dev_err(iproc_i2c->device, "'brcm,ape-hsls-addr-mask' missing\n"); return -EINVAL; } spin_lock_init(&iproc_i2c->idm_lock); /* no slave support */ bcm_iproc_algo.reg_slave = NULL; bcm_iproc_algo.unreg_slave = NULL; } ret = bcm_iproc_i2c_init(iproc_i2c); if (ret) return ret; ret = bcm_iproc_i2c_cfg_speed(iproc_i2c); if (ret) return ret; irq = platform_get_irq(pdev, 0); if (irq > 0) { ret = devm_request_irq(iproc_i2c->device, irq, bcm_iproc_i2c_isr, 0, pdev->name, iproc_i2c); if (ret < 0) { dev_err(iproc_i2c->device, "unable to request irq %i\n", irq); return ret; } iproc_i2c->irq = irq; } else { dev_warn(iproc_i2c->device, "no irq resource, falling back to poll mode\n"); } bcm_iproc_i2c_enable_disable(iproc_i2c, true); adap = &iproc_i2c->adapter; i2c_set_adapdata(adap, iproc_i2c); snprintf(adap->name, sizeof(adap->name), "Broadcom iProc (%s)", of_node_full_name(iproc_i2c->device->of_node)); adap->algo = &bcm_iproc_algo; adap->quirks = &bcm_iproc_i2c_quirks; adap->dev.parent = &pdev->dev; adap->dev.of_node = pdev->dev.of_node; return i2c_add_adapter(adap); } static int bcm_iproc_i2c_remove(struct platform_device *pdev) { struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev); if (iproc_i2c->irq) { /* * Make sure there's no pending interrupt when we remove the * adapter */ iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0); iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); synchronize_irq(iproc_i2c->irq); } i2c_del_adapter(&iproc_i2c->adapter); bcm_iproc_i2c_enable_disable(iproc_i2c, false); return 0; } #ifdef CONFIG_PM_SLEEP static int bcm_iproc_i2c_suspend(struct device *dev) { struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev); if (iproc_i2c->irq) { /* * Make sure there's no pending interrupt when we go into * suspend */ iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0); iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); synchronize_irq(iproc_i2c->irq); } /* now disable the controller */ bcm_iproc_i2c_enable_disable(iproc_i2c, false); return 0; } static int bcm_iproc_i2c_resume(struct device *dev) { struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev); int ret; u32 val; /* * Power domain could have been shut off completely in system deep * sleep, so re-initialize the block here */ ret = bcm_iproc_i2c_init(iproc_i2c); if (ret) return ret; /* configure to the desired bus speed */ val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET); val &= ~BIT(TIM_CFG_MODE_400_SHIFT); val |= (iproc_i2c->bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT; iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val); bcm_iproc_i2c_enable_disable(iproc_i2c, true); return 0; } static const struct dev_pm_ops bcm_iproc_i2c_pm_ops = { .suspend_late = &bcm_iproc_i2c_suspend, .resume_early = &bcm_iproc_i2c_resume }; #define BCM_IPROC_I2C_PM_OPS (&bcm_iproc_i2c_pm_ops) #else #define BCM_IPROC_I2C_PM_OPS NULL #endif /* CONFIG_PM_SLEEP */ static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave) { struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter); if (iproc_i2c->slave) return -EBUSY; if (slave->flags & I2C_CLIENT_TEN) return -EAFNOSUPPORT; iproc_i2c->slave = slave; tasklet_init(&iproc_i2c->slave_rx_tasklet, slave_rx_tasklet_fn, (unsigned long)iproc_i2c); bcm_iproc_i2c_slave_init(iproc_i2c, false); return 0; } static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave) { u32 tmp; struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter); if (!iproc_i2c->slave) return -EINVAL; disable_irq(iproc_i2c->irq); tasklet_kill(&iproc_i2c->slave_rx_tasklet); /* disable all slave interrupts */ tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); tmp &= ~(IE_S_ALL_INTERRUPT_MASK << IE_S_ALL_INTERRUPT_SHIFT); iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, tmp); /* Erase the slave address programmed */ tmp = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET); tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT); iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, tmp); /* flush TX/RX FIFOs */ tmp = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT)); iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, tmp); /* clear all pending slave interrupts */ iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE); iproc_i2c->slave = NULL; enable_irq(iproc_i2c->irq); return 0; } static const struct of_device_id bcm_iproc_i2c_of_match[] = { { .compatible = "brcm,iproc-i2c", .data = (int *)IPROC_I2C, }, { .compatible = "brcm,iproc-nic-i2c", .data = (int *)IPROC_I2C_NIC, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, bcm_iproc_i2c_of_match); static struct platform_driver bcm_iproc_i2c_driver = { .driver = { .name = "bcm-iproc-i2c", .of_match_table = bcm_iproc_i2c_of_match, .pm = BCM_IPROC_I2C_PM_OPS, }, .probe = bcm_iproc_i2c_probe, .remove = bcm_iproc_i2c_remove, }; module_platform_driver(bcm_iproc_i2c_driver); MODULE_AUTHOR("Ray Jui "); MODULE_DESCRIPTION("Broadcom iProc I2C Driver"); MODULE_LICENSE("GPL v2");