diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c index 57084696429c..554f83e34a2a 100644 --- a/drivers/i2c/busses/i2c-xiic.c +++ b/drivers/i2c/busses/i2c-xiic.c @@ -33,6 +33,7 @@ #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, @@ -64,6 +65,7 @@ enum xiic_endian { * @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 */ struct xiic_i2c { struct device *dev; @@ -83,6 +85,7 @@ struct xiic_i2c { bool dynamic; bool prev_msg_tx; u32 quirks; + bool smbus_block_read; }; struct xiic_version_data { @@ -346,6 +349,62 @@ 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, cr = 0, bytes_to_read = 0; @@ -368,6 +427,12 @@ static void xiic_read_rx(struct xiic_i2c *i2c) 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) { @@ -601,6 +666,12 @@ 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; @@ -741,11 +812,14 @@ static void xiic_start_recv(struct xiic_i2c *i2c) rfd_set = IIC_RX_FIFO_DEPTH - 1; } else if (rx_watermark == 1) { rfd_set = rx_watermark - 1; - /* Handle single byte transfer separately */ - cr |= XIIC_CR_NO_ACK_MASK; + + /* 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; - cr |= XIIC_CR_NO_ACK_MASK; } else { rfd_set = rx_watermark - 2; } @@ -984,7 +1058,7 @@ 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 = {