* [v2] i2c: brcmstb: Fix START and STOP conditions
@ 2017-03-03 1:55 Jaedon Shin
2017-03-03 4:32 ` Kamal Dasu
2017-03-09 14:40 ` Wolfram Sang
0 siblings, 2 replies; 3+ messages in thread
From: Jaedon Shin @ 2017-03-03 1:55 UTC (permalink / raw)
To: Wolfram Sang, Kamal Dasu, Florian Fainelli
Cc: bcm-kernel-feedback-list, linux-i2c, Jaedon Shin
The BSC data buffers to send and receive data are each of size 32 bytes
or 8 bytes 'xfersz' depending on SoC. The problem observed for all the
combined message transfer was if length of data transfer was a multiple
of 'xfersz' a repeated START was being transmitted by BSC driver. Fixed
this by appropriately setting START/STOP conditions for such transfers.
Fixes: dd1aa2524bc5 ("i2c: brcmstb: Add Broadcom settop SoC i2c controller driver")
Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
---
drivers/i2c/busses/i2c-brcmstb.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/busses/i2c-brcmstb.c b/drivers/i2c/busses/i2c-brcmstb.c
index 0652281662a8..78792b4d6437 100644
--- a/drivers/i2c/busses/i2c-brcmstb.c
+++ b/drivers/i2c/busses/i2c-brcmstb.c
@@ -465,6 +465,7 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
u8 *tmp_buf;
int len = 0;
int xfersz = brcmstb_i2c_get_xfersz(dev);
+ u32 cond, cond_per_msg;
if (dev->is_suspended)
return -EBUSY;
@@ -481,10 +482,11 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
- brcmstb_set_i2c_start_stop(dev, ~(COND_START_STOP));
+ cond = ~COND_START_STOP;
else
- brcmstb_set_i2c_start_stop(dev,
- COND_RESTART | COND_NOSTOP);
+ cond = COND_RESTART | COND_NOSTOP;
+
+ brcmstb_set_i2c_start_stop(dev, cond);
/* Send slave address */
if (!(pmsg->flags & I2C_M_NOSTART)) {
@@ -497,13 +499,24 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
}
}
+ cond_per_msg = cond;
+
/* Perform data transfer */
while (len) {
bytes_to_xfer = min(len, xfersz);
- if (len <= xfersz && i == (num - 1))
- brcmstb_set_i2c_start_stop(dev,
- ~(COND_START_STOP));
+ if (len <= xfersz) {
+ if (i == (num - 1))
+ cond_per_msg = cond_per_msg &
+ ~(COND_RESTART | COND_NOSTOP);
+ else
+ cond_per_msg = cond;
+ } else {
+ cond_per_msg = (cond_per_msg & ~COND_RESTART) |
+ COND_NOSTOP;
+ }
+
+ brcmstb_set_i2c_start_stop(dev, cond_per_msg);
rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
bytes_to_xfer, pmsg);
@@ -512,6 +525,8 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
len -= bytes_to_xfer;
tmp_buf += bytes_to_xfer;
+
+ cond_per_msg = COND_NOSTART | COND_NOSTOP;
}
}
--
2.12.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [v2] i2c: brcmstb: Fix START and STOP conditions
2017-03-03 1:55 [v2] i2c: brcmstb: Fix START and STOP conditions Jaedon Shin
@ 2017-03-03 4:32 ` Kamal Dasu
2017-03-09 14:40 ` Wolfram Sang
1 sibling, 0 replies; 3+ messages in thread
From: Kamal Dasu @ 2017-03-03 4:32 UTC (permalink / raw)
To: Jaedon Shin
Cc: Wolfram Sang, Florian Fainelli, bcm-kernel-feedback-list,
linux-i2c
On Thu, Mar 2, 2017 at 8:55 PM, Jaedon Shin <jaedon.shin@gmail.com> wrote:
> The BSC data buffers to send and receive data are each of size 32 bytes
> or 8 bytes 'xfersz' depending on SoC. The problem observed for all the
> combined message transfer was if length of data transfer was a multiple
> of 'xfersz' a repeated START was being transmitted by BSC driver. Fixed
> this by appropriately setting START/STOP conditions for such transfers.
>
> Fixes: dd1aa2524bc5 ("i2c: brcmstb: Add Broadcom settop SoC i2c controller driver")
> Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Acked-by: Kamal Dasu <kdasu.kdev@gmail.com>
> ---
> drivers/i2c/busses/i2c-brcmstb.c | 27 +++++++++++++++++++++------
> 1 file changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-brcmstb.c b/drivers/i2c/busses/i2c-brcmstb.c
> index 0652281662a8..78792b4d6437 100644
> --- a/drivers/i2c/busses/i2c-brcmstb.c
> +++ b/drivers/i2c/busses/i2c-brcmstb.c
> @@ -465,6 +465,7 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
> u8 *tmp_buf;
> int len = 0;
> int xfersz = brcmstb_i2c_get_xfersz(dev);
> + u32 cond, cond_per_msg;
>
> if (dev->is_suspended)
> return -EBUSY;
> @@ -481,10 +482,11 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
> pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
>
> if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
> - brcmstb_set_i2c_start_stop(dev, ~(COND_START_STOP));
> + cond = ~COND_START_STOP;
> else
> - brcmstb_set_i2c_start_stop(dev,
> - COND_RESTART | COND_NOSTOP);
> + cond = COND_RESTART | COND_NOSTOP;
> +
> + brcmstb_set_i2c_start_stop(dev, cond);
>
> /* Send slave address */
> if (!(pmsg->flags & I2C_M_NOSTART)) {
> @@ -497,13 +499,24 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
> }
> }
>
> + cond_per_msg = cond;
> +
> /* Perform data transfer */
> while (len) {
> bytes_to_xfer = min(len, xfersz);
>
> - if (len <= xfersz && i == (num - 1))
> - brcmstb_set_i2c_start_stop(dev,
> - ~(COND_START_STOP));
> + if (len <= xfersz) {
> + if (i == (num - 1))
> + cond_per_msg = cond_per_msg &
> + ~(COND_RESTART | COND_NOSTOP);
> + else
> + cond_per_msg = cond;
> + } else {
> + cond_per_msg = (cond_per_msg & ~COND_RESTART) |
> + COND_NOSTOP;
> + }
> +
> + brcmstb_set_i2c_start_stop(dev, cond_per_msg);
>
> rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
> bytes_to_xfer, pmsg);
> @@ -512,6 +525,8 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
>
> len -= bytes_to_xfer;
> tmp_buf += bytes_to_xfer;
> +
> + cond_per_msg = COND_NOSTART | COND_NOSTOP;
> }
> }
>
> --
> 2.12.0
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [v2] i2c: brcmstb: Fix START and STOP conditions
2017-03-03 1:55 [v2] i2c: brcmstb: Fix START and STOP conditions Jaedon Shin
2017-03-03 4:32 ` Kamal Dasu
@ 2017-03-09 14:40 ` Wolfram Sang
1 sibling, 0 replies; 3+ messages in thread
From: Wolfram Sang @ 2017-03-09 14:40 UTC (permalink / raw)
To: Jaedon Shin
Cc: Kamal Dasu, Florian Fainelli, bcm-kernel-feedback-list, linux-i2c
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On Fri, Mar 03, 2017 at 10:55:03AM +0900, Jaedon Shin wrote:
> The BSC data buffers to send and receive data are each of size 32 bytes
> or 8 bytes 'xfersz' depending on SoC. The problem observed for all the
> combined message transfer was if length of data transfer was a multiple
> of 'xfersz' a repeated START was being transmitted by BSC driver. Fixed
> this by appropriately setting START/STOP conditions for such transfers.
>
> Fixes: dd1aa2524bc5 ("i2c: brcmstb: Add Broadcom settop SoC i2c controller driver")
> Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Applied to for-current, thanks!
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2017-03-03 4:32 ` Kamal Dasu
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