On Wed, Oct 26, 2016 at 04:48:28PM +0700, tnhuynh@xxxxxxx wrote:
> From: Tin Huynh <tnhuynh@xxxxxxx>
>
> Free and Open IPMI use SMBUS BLOCK Read/Write to support SSIF protocol.
> However, I2C Designwave Core Driver doesn't handle the case at the moment.
> The below patch supports this feature.
Looks better now but I have still couple of comments.
First, the subject line should say something like:
i2c: designware: Implement support for SMBus block read and write
> Change from V1:
> -Remove empty lines
> -Add flags variable to make clean code
> -Change DW_DEFAULT_FUNCTIONALITY in i2c-designware-pcidrv.c
This changelog should be below the '---' in the patch.
> Signed-off-by: Tin Huynh <tnhuynh@xxxxxxx>
> ---
> drivers/i2c/busses/i2c-designware-core.c | 36 ++++++++++++++++++++++++--
> drivers/i2c/busses/i2c-designware-pcidrv.c | 1 +
> drivers/i2c/busses/i2c-designware-platdrv.c | 1 +
> 3 files changed, 35 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
> index 1fe93c4..c77a83f 100644
> --- a/drivers/i2c/busses/i2c-designware-core.c
> +++ b/drivers/i2c/busses/i2c-designware-core.c
> @@ -543,6 +543,7 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
> intr_mask = DW_IC_INTR_DEFAULT_MASK;
>
> for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
> + u32 flags = msgs[dev->msg_write_idx].flags;
> /*
> * if target address has changed, we need to
> * reprogram the target address in the i2c
> @@ -588,8 +589,15 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
> * detected from the registers so we set it always
> * when writing/reading the last byte.
> */
> +
> + /*
> + * i2c-core.c always set the buffer length of
> + * I2C_FUNC_SMBUS_BLOCK_DATA to 1. The length will
> + * be adjusted when receiving the first byte.
> + * Thus we can't stop the transaction here.
> + */
> if (dev->msg_write_idx == dev->msgs_num - 1 &&
> - buf_len == 1)
> + buf_len == 1 && !(flags & I2C_M_RECV_LEN))
> cmd |= BIT(9);
>
> if (need_restart) {
> @@ -614,7 +622,12 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
> dev->tx_buf = buf;
> dev->tx_buf_len = buf_len;
>
> - if (buf_len > 0) {
> + /*
> + * Because we don't know the buffer length in the
> + * I2C_FUNC_SMBUS_BLOCK_DATA case, we can't stop
> + * the transaction here.
> + */
> + if (buf_len > 0 || flags & I2C_M_RECV_LEN) {
> /* more bytes to be written */
> dev->status |= STATUS_WRITE_IN_PROGRESS;
> break;
> @@ -659,7 +672,24 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
> rx_valid = dw_readl(dev, DW_IC_RXFLR);
>
> for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
> - *buf++ = dw_readl(dev, DW_IC_DATA_CMD);
->
> + u32 flags = msgs[dev->msg_read_idx].flags;
> + *buf = dw_readl(dev, DW_IC_DATA_CMD);
> + /* ensure length byte is a valid value */
> + if (flags & I2C_M_RECV_LEN &&
> + *buf <= I2C_SMBUS_BLOCK_MAX && *buf > 0) {
> + /*
> + * Adjust the buffer length and mask the flag
> + * after receiving the first byte
> + */
> + len = (flags & I2C_CLIENT_PEC) ?
> + *buf + 2 : *buf + 1;
> + dev->tx_buf_len = len > dev->rx_outstanding ?
> + len - dev->rx_outstanding : 0;
> + msgs[dev->msg_read_idx].len = len;
> + flags &= ~I2C_M_RECV_LEN;
> + msgs[dev->msg_read_idx].flags = flags;
> + }
<- how about moving this block to a helper function?
> + buf++;
> dev->rx_outstanding--;
> }
>
> diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
> index 96f8230..8ffe2da 100644
> --- a/drivers/i2c/busses/i2c-designware-pcidrv.c
> +++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
> @@ -75,6 +75,7 @@ struct dw_pci_controller {
> I2C_FUNC_SMBUS_BYTE | \
> I2C_FUNC_SMBUS_BYTE_DATA | \
> I2C_FUNC_SMBUS_WORD_DATA | \
> + I2C_FUNC_SMBUS_BLOCK_DATA | \
> I2C_FUNC_SMBUS_I2C_BLOCK)
>
> /* Merrifield HCNT/LCNT/SDA hold time */
> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
> index 0b42a12..886fb62 100644
> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
> @@ -220,6 +220,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
> I2C_FUNC_SMBUS_BYTE |
> I2C_FUNC_SMBUS_BYTE_DATA |
> I2C_FUNC_SMBUS_WORD_DATA |
> + I2C_FUNC_SMBUS_BLOCK_DATA |
> I2C_FUNC_SMBUS_I2C_BLOCK;
>
> dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
> --
> 1.7.1
--
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