diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-xiic.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-xiic.c | 586 |
1 files changed, 531 insertions, 55 deletions
diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c index bee5a2ef1f22..dbb792fc197e 100644 --- a/drivers/i2c/busses/i2c-xiic.c +++ b/drivers/i2c/busses/i2c-xiic.c @@ -32,6 +32,8 @@ #include <linux/pm_runtime.h> #define DRIVER_NAME "xiic-i2c" +#define DYNAMIC_MODE_READ_BROKEN_BIT BIT(0) +#define SMBUS_BLOCK_READ_MIN_LEN 3 enum xilinx_i2c_state { STATE_DONE, @@ -44,6 +46,12 @@ enum xiic_endian { BIG }; +enum i2c_scl_freq { + REG_VALUES_100KHZ = 0, + REG_VALUES_400KHZ = 1, + REG_VALUES_1MHZ = 2 +}; + /** * struct xiic_i2c - Internal representation of the XIIC I2C bus * @dev: Pointer to device structure @@ -60,6 +68,12 @@ enum xiic_endian { * @clk: Pointer to AXI4-lite input clock * @state: See STATE_ * @singlemaster: Indicates bus is single master + * @dynamic: Mode of controller + * @prev_msg_tx: Previous message is Tx + * @quirks: To hold platform specific bug info + * @smbus_block_read: Flag to handle block read + * @input_clk: Input clock to I2C controller + * @i2c_clk: I2C SCL frequency */ struct xiic_i2c { struct device *dev; @@ -76,6 +90,39 @@ struct xiic_i2c { struct clk *clk; enum xilinx_i2c_state state; bool singlemaster; + bool dynamic; + bool prev_msg_tx; + u32 quirks; + bool smbus_block_read; + unsigned long input_clk; + unsigned int i2c_clk; +}; + +struct xiic_version_data { + u32 quirks; +}; + +/** + * struct timing_regs - AXI I2C timing registers that depend on I2C spec + * @tsusta: setup time for a repeated START condition + * @tsusto: setup time for a STOP condition + * @thdsta: hold time for a repeated START condition + * @tsudat: setup time for data + * @tbuf: bus free time between STOP and START + */ +struct timing_regs { + unsigned int tsusta; + unsigned int tsusto; + unsigned int thdsta; + unsigned int tsudat; + unsigned int tbuf; +}; + +/* Reg values in ns derived from I2C spec and AXI I2C PG for different frequencies */ +static const struct timing_regs timing_reg_values[] = { + { 5700, 5000, 4300, 550, 5000 }, /* Reg values for 100KHz */ + { 900, 900, 900, 400, 1600 }, /* Reg values for 400KHz */ + { 380, 380, 380, 170, 620 }, /* Reg values for 1MHz */ }; #define XIIC_MSB_OFFSET 0 @@ -96,6 +143,19 @@ struct xiic_i2c { #define XIIC_RFD_REG_OFFSET (0x20 + XIIC_REG_OFFSET) /* Rx FIFO Depth reg */ #define XIIC_GPO_REG_OFFSET (0x24 + XIIC_REG_OFFSET) /* Output Register */ +/* + * Timing register offsets from RegisterBase. These are used only for + * setting i2c clock frequency for the line. + */ +#define XIIC_TSUSTA_REG_OFFSET (0x28 + XIIC_REG_OFFSET) /* TSUSTA Register */ +#define XIIC_TSUSTO_REG_OFFSET (0x2C + XIIC_REG_OFFSET) /* TSUSTO Register */ +#define XIIC_THDSTA_REG_OFFSET (0x30 + XIIC_REG_OFFSET) /* THDSTA Register */ +#define XIIC_TSUDAT_REG_OFFSET (0x34 + XIIC_REG_OFFSET) /* TSUDAT Register */ +#define XIIC_TBUF_REG_OFFSET (0x38 + XIIC_REG_OFFSET) /* TBUF Register */ +#define XIIC_THIGH_REG_OFFSET (0x3C + XIIC_REG_OFFSET) /* THIGH Register */ +#define XIIC_TLOW_REG_OFFSET (0x40 + XIIC_REG_OFFSET) /* TLOW Register */ +#define XIIC_THDDAT_REG_OFFSET (0x44 + XIIC_REG_OFFSET) /* THDDAT Register */ + /* Control Register masks */ #define XIIC_CR_ENABLE_DEVICE_MASK 0x01 /* Device enable = 1 */ #define XIIC_CR_TX_FIFO_RESET_MASK 0x02 /* Transmit FIFO reset=1 */ @@ -143,6 +203,9 @@ struct xiic_i2c { #define XIIC_TX_DYN_START_MASK 0x0100 /* 1 = Set dynamic start */ #define XIIC_TX_DYN_STOP_MASK 0x0200 /* 1 = Set dynamic stop */ +/* Dynamic mode constants */ +#define MAX_READ_LENGTH_DYNAMIC 255 /* Max length for dynamic read */ + /* * The following constants define the register offsets for the Interrupt * registers. There are some holes in the memory map for reserved addresses @@ -275,12 +338,120 @@ static int xiic_clear_rx_fifo(struct xiic_i2c *i2c) return 0; } +static int xiic_wait_tx_empty(struct xiic_i2c *i2c) +{ + u8 isr; + unsigned long timeout; + + timeout = jiffies + XIIC_I2C_TIMEOUT; + for (isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET); + !(isr & XIIC_INTR_TX_EMPTY_MASK); + isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET)) { + if (time_after(jiffies, timeout)) { + dev_err(i2c->dev, "Timeout waiting at Tx empty\n"); + return -ETIMEDOUT; + } + } + + return 0; +} + +/** + * xiic_setclk - Sets the configured clock rate + * @i2c: Pointer to the xiic device structure + * + * The timing register values are calculated according to the input clock + * frequency and configured scl frequency. For details, please refer the + * AXI I2C PG and NXP I2C Spec. + * Supported frequencies are 100KHz, 400KHz and 1MHz. + * + * Return: 0 on success (Supported frequency selected or not configurable in SW) + * -EINVAL on failure (scl frequency not supported or THIGH is 0) + */ +static int xiic_setclk(struct xiic_i2c *i2c) +{ + unsigned int clk_in_mhz; + unsigned int index = 0; + u32 reg_val; + + dev_dbg(i2c->adap.dev.parent, + "%s entry, i2c->input_clk: %ld, i2c->i2c_clk: %d\n", + __func__, i2c->input_clk, i2c->i2c_clk); + + /* If not specified in DT, do not configure in SW. Rely only on Vivado design */ + if (!i2c->i2c_clk || !i2c->input_clk) + return 0; + + clk_in_mhz = DIV_ROUND_UP(i2c->input_clk, 1000000); + + switch (i2c->i2c_clk) { + case I2C_MAX_FAST_MODE_PLUS_FREQ: + index = REG_VALUES_1MHZ; + break; + case I2C_MAX_FAST_MODE_FREQ: + index = REG_VALUES_400KHZ; + break; + case I2C_MAX_STANDARD_MODE_FREQ: + index = REG_VALUES_100KHZ; + break; + default: + dev_warn(i2c->adap.dev.parent, "Unsupported scl frequency\n"); + return -EINVAL; + } + + /* + * Value to be stored in a register is the number of clock cycles required + * for the time duration. So the time is divided by the input clock time + * period to get the number of clock cycles required. Refer Xilinx AXI I2C + * PG document and I2C specification for further details. + */ + + /* THIGH - Depends on SCL clock frequency(i2c_clk) as below */ + reg_val = (DIV_ROUND_UP(i2c->input_clk, 2 * i2c->i2c_clk)) - 7; + if (reg_val == 0) + return -EINVAL; + + xiic_setreg32(i2c, XIIC_THIGH_REG_OFFSET, reg_val - 1); + + /* TLOW - Value same as THIGH */ + xiic_setreg32(i2c, XIIC_TLOW_REG_OFFSET, reg_val - 1); + + /* TSUSTA */ + reg_val = (timing_reg_values[index].tsusta * clk_in_mhz) / 1000; + xiic_setreg32(i2c, XIIC_TSUSTA_REG_OFFSET, reg_val - 1); + + /* TSUSTO */ + reg_val = (timing_reg_values[index].tsusto * clk_in_mhz) / 1000; + xiic_setreg32(i2c, XIIC_TSUSTO_REG_OFFSET, reg_val - 1); + + /* THDSTA */ + reg_val = (timing_reg_values[index].thdsta * clk_in_mhz) / 1000; + xiic_setreg32(i2c, XIIC_THDSTA_REG_OFFSET, reg_val - 1); + + /* TSUDAT */ + reg_val = (timing_reg_values[index].tsudat * clk_in_mhz) / 1000; + xiic_setreg32(i2c, XIIC_TSUDAT_REG_OFFSET, reg_val - 1); + + /* TBUF */ + reg_val = (timing_reg_values[index].tbuf * clk_in_mhz) / 1000; + xiic_setreg32(i2c, XIIC_TBUF_REG_OFFSET, reg_val - 1); + + /* THDDAT */ + xiic_setreg32(i2c, XIIC_THDDAT_REG_OFFSET, 1); + + return 0; +} + static int xiic_reinit(struct xiic_i2c *i2c) { int ret; xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK); + ret = xiic_setclk(i2c); + if (ret) + return ret; + /* Set receive Fifo depth to maximum (zero based). */ xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, IIC_RX_FIFO_DEPTH - 1); @@ -314,15 +485,72 @@ static void xiic_deinit(struct xiic_i2c *i2c) xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & ~XIIC_CR_ENABLE_DEVICE_MASK); } +static void xiic_smbus_block_read_setup(struct xiic_i2c *i2c) +{ + u8 rxmsg_len, rfd_set = 0; + + /* + * Clear the I2C_M_RECV_LEN flag to avoid setting + * message length again + */ + i2c->rx_msg->flags &= ~I2C_M_RECV_LEN; + + /* Set smbus_block_read flag to identify in isr */ + i2c->smbus_block_read = true; + + /* Read byte from rx fifo and set message length */ + rxmsg_len = xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET); + + i2c->rx_msg->buf[i2c->rx_pos++] = rxmsg_len; + + /* Check if received length is valid */ + if (rxmsg_len <= I2C_SMBUS_BLOCK_MAX) { + /* Set Receive fifo depth */ + if (rxmsg_len > IIC_RX_FIFO_DEPTH) { + /* + * When Rx msg len greater than or equal to Rx fifo capacity + * Receive fifo depth should set to Rx fifo capacity minus 1 + */ + rfd_set = IIC_RX_FIFO_DEPTH - 1; + i2c->rx_msg->len = rxmsg_len + 1; + } else if ((rxmsg_len == 1) || + (rxmsg_len == 0)) { + /* + * Minimum of 3 bytes required to exit cleanly. 1 byte + * already received, Second byte is being received. Have + * to set NACK in read_rx before receiving the last byte + */ + rfd_set = 0; + i2c->rx_msg->len = SMBUS_BLOCK_READ_MIN_LEN; + } else { + /* + * When Rx msg len less than Rx fifo capacity + * Receive fifo depth should set to Rx msg len minus 2 + */ + rfd_set = rxmsg_len - 2; + i2c->rx_msg->len = rxmsg_len + 1; + } + xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, rfd_set); + + return; + } + + /* Invalid message length, trigger STATE_ERROR with tx_msg_len in ISR */ + i2c->tx_msg->len = 3; + i2c->smbus_block_read = false; + dev_err(i2c->adap.dev.parent, "smbus_block_read Invalid msg length\n"); +} + static void xiic_read_rx(struct xiic_i2c *i2c) { - u8 bytes_in_fifo; + u8 bytes_in_fifo, cr = 0, bytes_to_read = 0; + u32 bytes_rem = 0; int i; bytes_in_fifo = xiic_getreg8(i2c, XIIC_RFO_REG_OFFSET) + 1; dev_dbg(i2c->adap.dev.parent, - "%s entry, bytes in fifo: %d, msg: %d, SR: 0x%x, CR: 0x%x\n", + "%s entry, bytes in fifo: %d, rem: %d, SR: 0x%x, CR: 0x%x\n", __func__, bytes_in_fifo, xiic_rx_space(i2c), xiic_getreg8(i2c, XIIC_SR_REG_OFFSET), xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); @@ -330,13 +558,58 @@ static void xiic_read_rx(struct xiic_i2c *i2c) if (bytes_in_fifo > xiic_rx_space(i2c)) bytes_in_fifo = xiic_rx_space(i2c); - for (i = 0; i < bytes_in_fifo; i++) + bytes_to_read = bytes_in_fifo; + + if (!i2c->dynamic) { + bytes_rem = xiic_rx_space(i2c) - bytes_in_fifo; + + /* Set msg length if smbus_block_read */ + if (i2c->rx_msg->flags & I2C_M_RECV_LEN) { + xiic_smbus_block_read_setup(i2c); + return; + } + + if (bytes_rem > IIC_RX_FIFO_DEPTH) { + bytes_to_read = bytes_in_fifo; + } else if (bytes_rem > 1) { + bytes_to_read = bytes_rem - 1; + } else if (bytes_rem == 1) { + bytes_to_read = 1; + /* Set NACK in CR to indicate slave transmitter */ + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr | + XIIC_CR_NO_ACK_MASK); + } else if (bytes_rem == 0) { + bytes_to_read = bytes_in_fifo; + + /* Generate stop on the bus if it is last message */ + if (i2c->nmsgs == 1) { + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & + ~XIIC_CR_MSMS_MASK); + } + + /* Make TXACK=0, clean up for next transaction */ + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & + ~XIIC_CR_NO_ACK_MASK); + } + } + + /* Read the fifo */ + for (i = 0; i < bytes_to_read; i++) { i2c->rx_msg->buf[i2c->rx_pos++] = xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET); + } - xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, - (xiic_rx_space(i2c) > IIC_RX_FIFO_DEPTH) ? - IIC_RX_FIFO_DEPTH - 1 : xiic_rx_space(i2c) - 1); + if (i2c->dynamic) { + u8 bytes; + + /* Receive remaining bytes if less than fifo depth */ + bytes = min_t(u8, xiic_rx_space(i2c), IIC_RX_FIFO_DEPTH); + bytes--; + xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, bytes); + } } static int xiic_tx_fifo_space(struct xiic_i2c *i2c) @@ -360,7 +633,22 @@ static void xiic_fill_tx_fifo(struct xiic_i2c *i2c) if (!xiic_tx_space(i2c) && i2c->nmsgs == 1) { /* last message in transfer -> STOP */ - data |= XIIC_TX_DYN_STOP_MASK; + if (i2c->dynamic) { + data |= XIIC_TX_DYN_STOP_MASK; + } else { + u8 cr; + int status; + + /* Wait till FIFO is empty so STOP is sent last */ + status = xiic_wait_tx_empty(i2c); + if (status) + return; + + /* Write to CR to stop */ + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & + ~XIIC_CR_MSMS_MASK); + } dev_dbg(i2c->adap.dev.parent, "%s TX STOP\n", __func__); } xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); @@ -401,7 +689,9 @@ static irqreturn_t xiic_process(int irq, void *dev_id) dev_dbg(i2c->adap.dev.parent, "%s: SR: 0x%x, msg: %p, nmsgs: %d\n", __func__, xiic_getreg8(i2c, XIIC_SR_REG_OFFSET), i2c->tx_msg, i2c->nmsgs); - + dev_dbg(i2c->adap.dev.parent, "%s, ISR: 0x%x, CR: 0x%x\n", + __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET), + xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); /* Service requesting interrupt */ if ((pend & XIIC_INTR_ARB_LOST_MASK) || @@ -512,6 +802,12 @@ static irqreturn_t xiic_process(int irq, void *dev_id) /* The bus is not busy, disable BusNotBusy interrupt */ xiic_irq_dis(i2c, XIIC_INTR_BNB_MASK); + if (i2c->tx_msg && i2c->smbus_block_read) { + i2c->smbus_block_read = false; + /* Set requested message len=1 to indicate STATE_DONE */ + i2c->tx_msg->len = 1; + } + if (!i2c->tx_msg) goto out; @@ -579,31 +875,113 @@ static int xiic_busy(struct xiic_i2c *i2c) static void xiic_start_recv(struct xiic_i2c *i2c) { u16 rx_watermark; + u8 cr = 0, rfd_set = 0; struct i2c_msg *msg = i2c->rx_msg = i2c->tx_msg; - /* Clear and enable Rx full interrupt. */ - xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | XIIC_INTR_TX_ERROR_MASK); + dev_dbg(i2c->adap.dev.parent, "%s entry, ISR: 0x%x, CR: 0x%x\n", + __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET), + xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); - /* we want to get all but last byte, because the TX_ERROR IRQ is used - * to inidicate error ACK on the address, and negative ack on the last - * received byte, so to not mix them receive all but last. - * In the case where there is only one byte to receive - * we can check if ERROR and RX full is set at the same time - */ - rx_watermark = msg->len; - if (rx_watermark > IIC_RX_FIFO_DEPTH) - rx_watermark = IIC_RX_FIFO_DEPTH; - xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, (u8)(rx_watermark - 1)); + /* Disable Tx interrupts */ + xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK | XIIC_INTR_TX_EMPTY_MASK); + + if (i2c->dynamic) { + u8 bytes; + u16 val; + + /* Clear and enable Rx full interrupt. */ + xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | + XIIC_INTR_TX_ERROR_MASK); + + /* + * We want to get all but last byte, because the TX_ERROR IRQ + * is used to indicate error ACK on the address, and + * negative ack on the last received byte, so to not mix + * them receive all but last. + * In the case where there is only one byte to receive + * we can check if ERROR and RX full is set at the same time + */ + rx_watermark = msg->len; + bytes = min_t(u8, rx_watermark, IIC_RX_FIFO_DEPTH); + + if (rx_watermark > 0) + bytes--; + xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, bytes); - if (!(msg->flags & I2C_M_NOSTART)) /* write the address */ xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, - i2c_8bit_addr_from_msg(msg) | XIIC_TX_DYN_START_MASK); + i2c_8bit_addr_from_msg(msg) | + XIIC_TX_DYN_START_MASK); + + /* If last message, include dynamic stop bit with length */ + val = (i2c->nmsgs == 1) ? XIIC_TX_DYN_STOP_MASK : 0; + val |= msg->len; + + xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, val); + + xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK); + } else { + /* + * If previous message is Tx, make sure that Tx FIFO is empty + * before starting a new transfer as the repeated start in + * standard mode can corrupt the transaction if there are + * still bytes to be transmitted in FIFO + */ + if (i2c->prev_msg_tx) { + int status; + + status = xiic_wait_tx_empty(i2c); + if (status) + return; + } - xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK); + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); - xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, - msg->len | ((i2c->nmsgs == 1) ? XIIC_TX_DYN_STOP_MASK : 0)); + /* Set Receive fifo depth */ + rx_watermark = msg->len; + if (rx_watermark > IIC_RX_FIFO_DEPTH) { + rfd_set = IIC_RX_FIFO_DEPTH - 1; + } else if (rx_watermark == 1) { + rfd_set = rx_watermark - 1; + + /* Set No_ACK, except for smbus_block_read */ + if (!(i2c->rx_msg->flags & I2C_M_RECV_LEN)) { + /* Handle single byte transfer separately */ + cr |= XIIC_CR_NO_ACK_MASK; + } + } else if (rx_watermark == 0) { + rfd_set = rx_watermark; + } else { + rfd_set = rx_watermark - 2; + } + /* Check if RSTA should be set */ + if (cr & XIIC_CR_MSMS_MASK) { + /* Already a master, RSTA should be set */ + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, (cr | + XIIC_CR_REPEATED_START_MASK) & + ~(XIIC_CR_DIR_IS_TX_MASK)); + } + + xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, rfd_set); + + /* Clear and enable Rx full and transmit complete interrupts */ + xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | + XIIC_INTR_TX_ERROR_MASK); + + /* Write the address */ + xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, + i2c_8bit_addr_from_msg(msg)); + + /* Write to Control Register,to start transaction in Rx mode */ + if ((cr & XIIC_CR_MSMS_MASK) == 0) { + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, (cr | + XIIC_CR_MSMS_MASK) + & ~(XIIC_CR_DIR_IS_TX_MASK)); + } + dev_dbg(i2c->adap.dev.parent, "%s end, ISR: 0x%x, CR: 0x%x\n", + __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET), + xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); + } if (i2c->nmsgs == 1) /* very last, enable bus not busy as well */ @@ -611,10 +989,17 @@ static void xiic_start_recv(struct xiic_i2c *i2c) /* the message is tx:ed */ i2c->tx_pos = msg->len; + + /* Enable interrupts */ + xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK); + + i2c->prev_msg_tx = false; } static void xiic_start_send(struct xiic_i2c *i2c) { + u8 cr = 0; + u16 data; struct i2c_msg *msg = i2c->tx_msg; dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, len: %d", @@ -623,24 +1008,70 @@ static void xiic_start_send(struct xiic_i2c *i2c) __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET), xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); - if (!(msg->flags & I2C_M_NOSTART)) { + if (i2c->dynamic) { /* write the address */ - u16 data = i2c_8bit_addr_from_msg(msg) | - XIIC_TX_DYN_START_MASK; - if ((i2c->nmsgs == 1) && msg->len == 0) + data = i2c_8bit_addr_from_msg(msg) | + XIIC_TX_DYN_START_MASK; + + if (i2c->nmsgs == 1 && msg->len == 0) /* no data and last message -> add STOP */ data |= XIIC_TX_DYN_STOP_MASK; xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); - } - /* Clear any pending Tx empty, Tx Error and then enable them. */ - xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_ERROR_MASK | - XIIC_INTR_BNB_MASK | - ((i2c->nmsgs > 1 || xiic_tx_space(i2c)) ? - XIIC_INTR_TX_HALF_MASK : 0)); + /* Clear any pending Tx empty, Tx Error and then enable them */ + xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | + XIIC_INTR_TX_ERROR_MASK | + XIIC_INTR_BNB_MASK | + ((i2c->nmsgs > 1 || xiic_tx_space(i2c)) ? + XIIC_INTR_TX_HALF_MASK : 0)); + + xiic_fill_tx_fifo(i2c); + } else { + /* + * If previous message is Tx, make sure that Tx FIFO is empty + * before starting a new transfer as the repeated start in + * standard mode can corrupt the transaction if there are + * still bytes to be transmitted in FIFO + */ + if (i2c->prev_msg_tx) { + int status; + + status = xiic_wait_tx_empty(i2c); + if (status) + return; + } + /* Check if RSTA should be set */ + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + if (cr & XIIC_CR_MSMS_MASK) { + /* Already a master, RSTA should be set */ + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, (cr | + XIIC_CR_REPEATED_START_MASK | + XIIC_CR_DIR_IS_TX_MASK) & + ~(XIIC_CR_NO_ACK_MASK)); + } + + /* Write address to FIFO */ + data = i2c_8bit_addr_from_msg(msg); + xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); + + /* Fill fifo */ + xiic_fill_tx_fifo(i2c); - xiic_fill_tx_fifo(i2c); + if ((cr & XIIC_CR_MSMS_MASK) == 0) { + /* Start Tx by writing to CR */ + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr | + XIIC_CR_MSMS_MASK | + XIIC_CR_DIR_IS_TX_MASK); + } + + /* Clear any pending Tx empty, Tx Error and then enable them */ + xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | + XIIC_INTR_TX_ERROR_MASK | + XIIC_INTR_BNB_MASK); + } + i2c->prev_msg_tx = true; } static void __xiic_start_xfer(struct xiic_i2c *i2c) @@ -666,7 +1097,8 @@ static void __xiic_start_xfer(struct xiic_i2c *i2c) static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num) { - int ret; + bool broken_read, max_read_len, smbus_blk_read; + int ret, count; mutex_lock(&i2c->lock); @@ -679,6 +1111,34 @@ static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num) i2c->nmsgs = num; init_completion(&i2c->completion); + /* Decide standard mode or Dynamic mode */ + i2c->dynamic = true; + + /* Initialize prev message type */ + i2c->prev_msg_tx = false; + + /* + * Scan through nmsgs, use dynamic mode when none of the below three + * conditions occur. We need standard mode even if one condition holds + * true in the entire array of messages in a single transfer. + * If read transaction as dynamic mode is broken for delayed reads + * in xlnx,axi-iic-2.0 / xlnx,xps-iic-2.00.a IP versions. + * If read length is > 255 bytes. + * If smbus_block_read transaction. + */ + for (count = 0; count < i2c->nmsgs; count++) { + broken_read = (i2c->quirks & DYNAMIC_MODE_READ_BROKEN_BIT) && + (i2c->tx_msg[count].flags & I2C_M_RD); + max_read_len = (i2c->tx_msg[count].flags & I2C_M_RD) && + (i2c->tx_msg[count].len > MAX_READ_LENGTH_DYNAMIC); + smbus_blk_read = (i2c->tx_msg[count].flags & I2C_M_RECV_LEN); + + if (broken_read || max_read_len || smbus_blk_read) { + i2c->dynamic = false; + break; + } + } + ret = xiic_reinit(i2c); if (!ret) __xiic_start_xfer(i2c); @@ -714,10 +1174,6 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) i2c->rx_msg = NULL; i2c->nmsgs = 0; err = -ETIMEDOUT; - } else if (err < 0) { /* Completion error */ - i2c->tx_msg = NULL; - i2c->rx_msg = NULL; - i2c->nmsgs = 0; } else { err = (i2c->state == STATE_DONE) ? num : -EIO; } @@ -729,7 +1185,7 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) static u32 xiic_func(struct i2c_adapter *adap) { - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA; } static const struct i2c_algorithm xiic_algorithm = { @@ -737,21 +1193,30 @@ static const struct i2c_algorithm xiic_algorithm = { .functionality = xiic_func, }; -static const struct i2c_adapter_quirks xiic_quirks = { - .max_read_len = 255, -}; - static const struct i2c_adapter xiic_adapter = { .owner = THIS_MODULE, .class = I2C_CLASS_DEPRECATED, .algo = &xiic_algorithm, - .quirks = &xiic_quirks, }; +static const struct xiic_version_data xiic_2_00 = { + .quirks = DYNAMIC_MODE_READ_BROKEN_BIT, +}; + +#if defined(CONFIG_OF) +static const struct of_device_id xiic_of_match[] = { + { .compatible = "xlnx,xps-iic-2.00.a", .data = &xiic_2_00 }, + { .compatible = "xlnx,axi-iic-2.1", }, + {}, +}; +MODULE_DEVICE_TABLE(of, xiic_of_match); +#endif + static int xiic_i2c_probe(struct platform_device *pdev) { struct xiic_i2c *i2c; struct xiic_i2c_platform_data *pdata; + const struct of_device_id *match; struct resource *res; int ret, irq; u8 i; @@ -761,6 +1226,13 @@ static int xiic_i2c_probe(struct platform_device *pdev) if (!i2c) return -ENOMEM; + match = of_match_node(xiic_of_match, pdev->dev.of_node); + if (match && match->data) { + const struct xiic_version_data *data = match->data; + + i2c->quirks = data->quirks; + } + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); i2c->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(i2c->base)) @@ -798,6 +1270,15 @@ static int xiic_i2c_probe(struct platform_device *pdev) pm_runtime_use_autosuspend(i2c->dev); pm_runtime_set_active(i2c->dev); pm_runtime_enable(i2c->dev); + + /* SCL frequency configuration */ + i2c->input_clk = clk_get_rate(i2c->clk); + ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency", + &i2c->i2c_clk); + /* If clock-frequency not specified in DT, do not configure in SW */ + if (ret || i2c->i2c_clk > I2C_MAX_FAST_MODE_PLUS_FREQ) + i2c->i2c_clk = 0; + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, xiic_process, IRQF_ONESHOT, pdev->name, i2c); @@ -841,6 +1322,9 @@ static int xiic_i2c_probe(struct platform_device *pdev) i2c_new_client_device(&i2c->adap, pdata->devices + i); } + dev_dbg(&pdev->dev, "mmio %08lx irq %d scl clock frequency %d\n", + (unsigned long)res->start, irq, i2c->i2c_clk); + return 0; err_clk_dis: @@ -875,14 +1359,6 @@ static int xiic_i2c_remove(struct platform_device *pdev) return 0; } -#if defined(CONFIG_OF) -static const struct of_device_id xiic_of_match[] = { - { .compatible = "xlnx,xps-iic-2.00.a", }, - {}, -}; -MODULE_DEVICE_TABLE(of, xiic_of_match); -#endif - static int __maybe_unused xiic_i2c_runtime_suspend(struct device *dev) { struct xiic_i2c *i2c = dev_get_drvdata(dev); |