Re: [PATCH 1/1] i2c: iproc: Add multi byte read-write support for slave mode
From: Rayagonda Kokatanur
Date: Sun May 26 2019 - 23:32:21 EST
Hi All,
Please review the patch and let me know your review comments if any.
Best regards,
Rayagonda
On Wed, May 15, 2019 at 9:58 PM Rayagonda Kokatanur
<rayagonda.kokatanur@xxxxxxxxxxxx> wrote:
>
> No change, it's just duplicate, please ignore first patch and review
> second patch.
>
> Best regards
> Rayagonda
>
>
>
> On Thu, May 9, 2019 at 9:58 PM Ray Jui <ray.jui@xxxxxxxxxxxx> wrote:
> >
> > Why is the email sent twice? What has changed?
> >
> > On 5/8/2019 9:21 PM, Rayagonda Kokatanur wrote:
> > > Add multiple byte read-write support for slave mode.
> > >
> > > Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@xxxxxxxxxxxx>
> > > Signed-off-by: Srinath Mannam <srinath.mannam@xxxxxxxxxxxx>
> > > ---
> > > drivers/i2c/busses/i2c-bcm-iproc.c | 117 +++++++++++++++++--------------------
> > > 1 file changed, 53 insertions(+), 64 deletions(-)
> > >
> > > diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
> > > index a845b8d..2c7f145 100644
> > > --- a/drivers/i2c/busses/i2c-bcm-iproc.c
> > > +++ b/drivers/i2c/busses/i2c-bcm-iproc.c
> > > @@ -165,12 +165,6 @@ enum i2c_slave_read_status {
> > > I2C_SLAVE_RX_END,
> > > };
> > >
> > > -enum i2c_slave_xfer_dir {
> > > - I2C_SLAVE_DIR_READ = 0,
> > > - I2C_SLAVE_DIR_WRITE,
> > > - I2C_SLAVE_DIR_NONE,
> > > -};
> > > -
> > > enum bus_speed_index {
> > > I2C_SPD_100K = 0,
> > > I2C_SPD_400K,
> > > @@ -203,7 +197,6 @@ struct bcm_iproc_i2c_dev {
> > > struct i2c_msg *msg;
> > >
> > > struct i2c_client *slave;
> > > - enum i2c_slave_xfer_dir xfer_dir;
> > >
> > > /* bytes that have been transferred */
> > > unsigned int tx_bytes;
> > > @@ -219,7 +212,8 @@ struct bcm_iproc_i2c_dev {
> > > | 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_RX_EVENT_SHIFT) | BIT(IS_S_RD_EVENT_SHIFT)\
> > > + | BIT(IS_S_TX_UNDERRUN_SHIFT))
> > >
> > > static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave);
> > > static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave);
> > > @@ -297,15 +291,11 @@ static void bcm_iproc_i2c_slave_init(
> > > /* clear all pending slave interrupts */
> > > iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE);
> > >
> > > - /* Enable interrupt register for any READ event */
> > > - val = BIT(IE_S_RD_EVENT_SHIFT);
> > > /* Enable interrupt register to indicate a valid byte in receive fifo */
> > > - val |= BIT(IE_S_RX_EVENT_SHIFT);
> > > + val = BIT(IE_S_RX_EVENT_SHIFT);
> > > /* Enable interrupt register for the Slave BUSY command */
> > > val |= BIT(IE_S_START_BUSY_SHIFT);
> > > iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
> > > -
> > > - iproc_i2c->xfer_dir = I2C_SLAVE_DIR_NONE;
> > > }
> > >
> > > static void bcm_iproc_i2c_check_slave_status(
> > > @@ -314,8 +304,11 @@ static void bcm_iproc_i2c_check_slave_status(
> > > u32 val;
> > >
> > > val = iproc_i2c_rd_reg(iproc_i2c, S_CMD_OFFSET);
> > > - val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK;
> > > + /* 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) {
> > > dev_err(iproc_i2c->device, "slave random stretch time timeout\n");
> > >
> > > @@ -327,70 +320,66 @@ static void bcm_iproc_i2c_check_slave_status(
> > > }
> > >
> > > static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
> > > - u32 status)
> > > + u32 status)
> > > {
> > > - u8 value;
> > > u32 val;
> > > - u32 rd_status;
> > > - u32 tmp;
> > > + u8 value, rx_status;
> > >
> > > - /* Start of transaction. check address and populate the direction */
> > > - if (iproc_i2c->xfer_dir == I2C_SLAVE_DIR_NONE) {
> > > - tmp = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET);
> > > - rd_status = (tmp >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK;
> > > - /* This condition checks whether the request is a new request */
> > > - if (((rd_status == I2C_SLAVE_RX_START) &&
> > > - (status & BIT(IS_S_RX_EVENT_SHIFT))) ||
> > > - ((rd_status == I2C_SLAVE_RX_END) &&
> > > - (status & BIT(IS_S_RD_EVENT_SHIFT)))) {
> > > -
> > > - /* Last bit is W/R bit.
> > > - * If 1 then its a read request(by master).
> > > - */
> > > - iproc_i2c->xfer_dir = tmp & SLAVE_READ_WRITE_BIT_MASK;
> > > - if (iproc_i2c->xfer_dir == I2C_SLAVE_DIR_WRITE)
> > > - i2c_slave_event(iproc_i2c->slave,
> > > - I2C_SLAVE_READ_REQUESTED, &value);
> > > - else
> > > - i2c_slave_event(iproc_i2c->slave,
> > > + /* Slave RX byte receive */
> > > + if (status & BIT(IS_S_RX_EVENT_SHIFT)) {
> > > + val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET);
> > > + rx_status = (val >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK;
> > > + if (rx_status == I2C_SLAVE_RX_START) {
> > > + /* Start of SMBUS for Master write */
> > > + i2c_slave_event(iproc_i2c->slave,
> > > I2C_SLAVE_WRITE_REQUESTED, &value);
> > > - }
> > > - }
> > >
> > > - /* read request from master */
> > > - if ((status & BIT(IS_S_RD_EVENT_SHIFT)) &&
> > > - (iproc_i2c->xfer_dir == I2C_SLAVE_DIR_WRITE)) {
> > > - i2c_slave_event(iproc_i2c->slave,
> > > - I2C_SLAVE_READ_PROCESSED, &value);
> > > - iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
> > > + val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET);
> > > + value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
> > > + i2c_slave_event(iproc_i2c->slave,
> > > + I2C_SLAVE_WRITE_RECEIVED, &value);
> > > + } else if (status & BIT(IS_S_RD_EVENT_SHIFT)) {
> > > + /* Start of SMBUS for Master Read */
> > > + i2c_slave_event(iproc_i2c->slave,
> > > + I2C_SLAVE_READ_REQUESTED, &value);
> > > + iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
> > >
> > > - val = BIT(S_CMD_START_BUSY_SHIFT);
> > > - iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
> > > - }
> > > + val = BIT(S_CMD_START_BUSY_SHIFT);
> > > + iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
> > >
> > > - /* write request from master */
> > > - if ((status & BIT(IS_S_RX_EVENT_SHIFT)) &&
> > > - (iproc_i2c->xfer_dir == I2C_SLAVE_DIR_READ)) {
> > > - val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET);
> > > - /* Its a write request by Master to Slave.
> > > - * We read data present in receive FIFO
> > > - */
> > > - value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
> > > + /*
> > > + * Enable interrupt for TX FIFO becomes empty and
> > > + * less than PKT_LENGTH bytes were output on the SMBUS
> > > + */
> > > + val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
> > > + val |= BIT(IE_S_TX_UNDERRUN_SHIFT);
> > > + iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
> > > + } else {
> > > + /* Master write other than start */
> > > + value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
> > > + i2c_slave_event(iproc_i2c->slave,
> > > + I2C_SLAVE_WRITE_RECEIVED, &value);
> > > + }
> > > + } else if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) {
> > > + /* Master read other than start */
> > > i2c_slave_event(iproc_i2c->slave,
> > > - I2C_SLAVE_WRITE_RECEIVED, &value);
> > > -
> > > - /* check the status for the last byte of the transaction */
> > > - rd_status = (val >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK;
> > > - if (rd_status == I2C_SLAVE_RX_END)
> > > - iproc_i2c->xfer_dir = I2C_SLAVE_DIR_NONE;
> > > + I2C_SLAVE_READ_PROCESSED, &value);
> > >
> > > - dev_dbg(iproc_i2c->device, "\nread value = 0x%x\n", value);
> > > + iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
> > > + val = BIT(S_CMD_START_BUSY_SHIFT);
> > > + iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
> > > }
> > >
> > > /* Stop */
> > > if (status & BIT(IS_S_START_BUSY_SHIFT)) {
> > > i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value);
> > > - iproc_i2c->xfer_dir = I2C_SLAVE_DIR_NONE;
> > > + /*
> > > + * Enable interrupt for TX FIFO becomes empty and
> > > + * less than PKT_LENGTH bytes were output on the SMBUS
> > > + */
> > > + val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
> > > + val &= ~BIT(IE_S_TX_UNDERRUN_SHIFT);
> > > + iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
> > > }
> > >
> > > /* clear interrupt status */
> > >