* [PATCH v2 1/1] Input: atmel_mxt_ts - implement I2C retries
@ 2020-09-03 15:59 Jiada Wang
2020-09-05 14:06 ` Dmitry Osipenko
[not found] ` <CAHp75Vfw1bJ+0pRJKVJ=nCJ-5rVzYLjkP4iWPqiG-it0qp5GFg@mail.gmail.com>
0 siblings, 2 replies; 4+ messages in thread
From: Jiada Wang @ 2020-09-03 15:59 UTC (permalink / raw)
To: nick, dmitry.torokhov
Cc: linux-input, linux-kernel, Andrew_Gabbasov, erosca, digetx, jiada_wang
From: Nick Dyer <nick.dyer@itdev.co.uk>
Some maXTouch chips (eg mXT1386) will not respond on the first I2C request
when they are in a sleep state. It must be retried after a delay for the
chip to wake up.
Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Acked-by: Yufeng Shen <miletus@chromium.org>
(cherry picked from ndyer/linux/for-upstream commit 63fd7a2cd03c3a572a5db39c52f4856819e1835d)
[gdavis: Forward port and fix conflicts.]
Signed-off-by: George G. Davis <george_davis@mentor.com>
[jiada: return exact errno when i2c_transfer & i2c_master_send fails]
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 45 ++++++++++++++++--------
1 file changed, 30 insertions(+), 15 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index a2189739e30f..5d4cb15d21dc 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -196,6 +196,7 @@ enum t100_type {
#define MXT_CRC_TIMEOUT 1000 /* msec */
#define MXT_FW_RESET_TIME 3000 /* msec */
#define MXT_FW_CHG_TIMEOUT 300 /* msec */
+#define MXT_WAKEUP_TIME 25 /* msec */
/* Command to unlock bootloader */
#define MXT_UNLOCK_CMD_MSB 0xaa
@@ -626,6 +627,7 @@ static int __mxt_read_reg(struct i2c_client *client,
struct i2c_msg xfer[2];
u8 buf[2];
int ret;
+ bool retry = false;
buf[0] = reg & 0xff;
buf[1] = (reg >> 8) & 0xff;
@@ -642,17 +644,22 @@ static int __mxt_read_reg(struct i2c_client *client,
xfer[1].len = len;
xfer[1].buf = val;
- ret = i2c_transfer(client->adapter, xfer, 2);
- if (ret == 2) {
- ret = 0;
- } else {
- if (ret >= 0)
- ret = -EIO;
- dev_err(&client->dev, "%s: i2c transfer failed (%d)\n",
- __func__, ret);
+retry_read:
+ ret = i2c_transfer(client->adapter, xfer, ARRAY_SIZE(xfer));
+ if (ret != ARRAY_SIZE(xfer)) {
+ if (!retry) {
+ dev_dbg(&client->dev, "%s: i2c retry\n", __func__);
+ msleep(MXT_WAKEUP_TIME);
+ retry = true;
+ goto retry_read;
+ } else {
+ dev_err(&client->dev, "%s: i2c transfer failed (%d)\n",
+ __func__, ret);
+ return ret < 0 ? ret : -EIO;
+ }
}
- return ret;
+ return 0;
}
static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len,
@@ -661,6 +668,7 @@ static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len,
u8 *buf;
size_t count;
int ret;
+ bool retry = false;
count = len + 2;
buf = kmalloc(count, GFP_KERNEL);
@@ -671,14 +679,21 @@ static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16 len,
buf[1] = (reg >> 8) & 0xff;
memcpy(&buf[2], val, len);
+retry_write:
ret = i2c_master_send(client, buf, count);
- if (ret == count) {
- ret = 0;
+ if (ret != count) {
+ if (!retry) {
+ dev_dbg(&client->dev, "%s: i2c retry\n", __func__);
+ msleep(MXT_WAKEUP_TIME);
+ retry = true;
+ goto retry_write;
+ } else {
+ dev_err(&client->dev, "%s: i2c send failed (%d)\n",
+ __func__, ret);
+ ret = ret < 0 ? ret : -EIO;
+ }
} else {
- if (ret >= 0)
- ret = -EIO;
- dev_err(&client->dev, "%s: i2c send failed (%d)\n",
- __func__, ret);
+ ret = 0;
}
kfree(buf);
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2 1/1] Input: atmel_mxt_ts - implement I2C retries
2020-09-03 15:59 [PATCH v2 1/1] Input: atmel_mxt_ts - implement I2C retries Jiada Wang
@ 2020-09-05 14:06 ` Dmitry Osipenko
[not found] ` <CAHp75Vfw1bJ+0pRJKVJ=nCJ-5rVzYLjkP4iWPqiG-it0qp5GFg@mail.gmail.com>
1 sibling, 0 replies; 4+ messages in thread
From: Dmitry Osipenko @ 2020-09-05 14:06 UTC (permalink / raw)
To: Jiada Wang, nick, dmitry.torokhov
Cc: linux-input, linux-kernel, Andrew_Gabbasov, erosca
03.09.2020 18:59, Jiada Wang пишет:
> From: Nick Dyer <nick.dyer@itdev.co.uk>
>
> Some maXTouch chips (eg mXT1386) will not respond on the first I2C request
> when they are in a sleep state. It must be retried after a delay for the
> chip to wake up.
>
> Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
> Acked-by: Yufeng Shen <miletus@chromium.org>
> (cherry picked from ndyer/linux/for-upstream commit 63fd7a2cd03c3a572a5db39c52f4856819e1835d)
> [gdavis: Forward port and fix conflicts.]
> Signed-off-by: George G. Davis <george_davis@mentor.com>
> [jiada: return exact errno when i2c_transfer & i2c_master_send fails]
> Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
> ---
> drivers/input/touchscreen/atmel_mxt_ts.c | 45 ++++++++++++++++--------
> 1 file changed, 30 insertions(+), 15 deletions(-)
Hello, Jiada!
Everything works well on Acer A500 tablet device that uses mXT1386 for
the touchscreen controller! Thank you very much!
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 1/1] Input: atmel_mxt_ts - implement I2C retries
[not found] ` <CAHp75Vfw1bJ+0pRJKVJ=nCJ-5rVzYLjkP4iWPqiG-it0qp5GFg@mail.gmail.com>
@ 2020-09-05 18:57 ` Dmitry Osipenko
2020-09-12 0:50 ` Wang, Jiada
1 sibling, 0 replies; 4+ messages in thread
From: Dmitry Osipenko @ 2020-09-05 18:57 UTC (permalink / raw)
To: Andy Shevchenko, Jiada Wang
Cc: nick, dmitry.torokhov, linux-input, linux-kernel,
Andrew_Gabbasov, erosca
05.09.2020 21:02, Andy Shevchenko пишет:
...
> #define MXT_CRC_TIMEOUT 1000 /* msec */
> #define MXT_FW_RESET_TIME 3000 /* msec */
> #define MXT_FW_CHG_TIMEOUT 300 /* msec */
> +#define MXT_WAKEUP_TIME 25 /* msec */
>
>
> Can we simple add _MS unit suffix to the definition?
I'd expect this
> /* Command to unlock bootloader */
> #define MXT_UNLOCK_CMD_MSB 0xaa
> @@ -626,6 +627,7 @@ static int __mxt_read_reg(struct i2c_client *client,
> struct i2c_msg xfer[2];
> u8 buf[2];
> int ret;
> + bool retry = false;
>
>
> Keep this ordered by length.
and this to be separate patches that are cleaning whole driver code,
otherwise there are no much benefits.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 1/1] Input: atmel_mxt_ts - implement I2C retries
[not found] ` <CAHp75Vfw1bJ+0pRJKVJ=nCJ-5rVzYLjkP4iWPqiG-it0qp5GFg@mail.gmail.com>
2020-09-05 18:57 ` Dmitry Osipenko
@ 2020-09-12 0:50 ` Wang, Jiada
1 sibling, 0 replies; 4+ messages in thread
From: Wang, Jiada @ 2020-09-12 0:50 UTC (permalink / raw)
To: Andy Shevchenko
Cc: nick, dmitry.torokhov, linux-input, linux-kernel,
Andrew_Gabbasov, erosca, digetx
Hi Andy
Thanks for your comment
On 2020/09/06 3:02, Andy Shevchenko wrote:
>
>
> On Thursday, September 3, 2020, Jiada Wang <jiada_wang@mentor.com
> <mailto:jiada_wang@mentor.com>> wrote:
>
> From: Nick Dyer <nick.dyer@itdev.co.uk <mailto:nick.dyer@itdev.co.uk>>
>
> Some maXTouch chips (eg mXT1386) will not respond on the first I2C
> request
> when they are in a sleep state. It must be retried after a delay for the
> chip to wake up.
>
> Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk
> <mailto:nick.dyer@itdev.co.uk>>
> Acked-by: Yufeng Shen <miletus@chromium.org
> <mailto:miletus@chromium.org>>
>
>
> (cherry picked from ndyer/linux/for-upstream commit
> 63fd7a2cd03c3a572a5db39c52f4856819e1835d)
>
>
> It’s a noise for upstream.
>
sure, I will remove it
> [gdavis: Forward port and fix conflicts.]
> Signed-off-by: George G. Davis <george_davis@mentor.com
> <mailto:george_davis@mentor.com>>
> [jiada: return exact errno when i2c_transfer & i2c_master_send fails]
> Signed-off-by: Jiada Wang <jiada_wang@mentor.com
> <mailto:jiada_wang@mentor.com>>
> ---
> drivers/input/touchscreen/atmel_mxt_ts.c | 45 ++++++++++++++++--------
> 1 file changed, 30 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c
> b/drivers/input/touchscreen/atmel_mxt_ts.c
> index a2189739e30f..5d4cb15d21dc 100644
> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
> @@ -196,6 +196,7 @@ enum t100_type {
> #define MXT_CRC_TIMEOUT 1000 /* msec */
> #define MXT_FW_RESET_TIME 3000 /* msec */
> #define MXT_FW_CHG_TIMEOUT 300 /* msec */
> +#define MXT_WAKEUP_TIME 25 /* msec */
>
>
> Can we simple add _MS unit suffix to the definition?
As Dmitry commented, I'd like to keep it as-is, probably a separate
patch to update all these together.
>
>
> /* Command to unlock bootloader */
> #define MXT_UNLOCK_CMD_MSB 0xaa
> @@ -626,6 +627,7 @@ static int __mxt_read_reg(struct i2c_client *client,
> struct i2c_msg xfer[2];
> u8 buf[2];
> int ret;
> + bool retry = false;
>
>
> Keep this ordered by length.
I will move "retry" upper.
>
>
> buf[0] = reg & 0xff;
> buf[1] = (reg >> 8) & 0xff;
> @@ -642,17 +644,22 @@ static int __mxt_read_reg(struct i2c_client
> *client,
> xfer[1].len = len;
> xfer[1].buf = val;
>
> - ret = i2c_transfer(client->adapter, xfer, 2);
> - if (ret == 2) {
> - ret = 0;
> - } else {
> - if (ret >= 0)
> - ret = -EIO;
> - dev_err(&client->dev, "%s: i2c transfer failed (%d)\n",
> - __func__, ret);
> +retry_read:
> + ret = i2c_transfer(client->adapter, xfer, ARRAY_SIZE(xfer));
> + if (ret != ARRAY_SIZE(xfer)) {
> + if (!retry) {
>
>
> Why not positive conditional?
to me, it's not much different either positive or negative conditional,
can you elaborate more about this?
>
> + dev_dbg(&client->dev, "%s: i2c retry\n",
> __func__);
>
>
> __func__ is redundant for dev_dbg().
>
> + msleep(MXT_WAKEUP_TIME);
> + retry = true;
> + goto retry_read;
>
> + } else {
>
>
> Redundant in either case of conditional. Allows to drop indentation level.
I will remove the redundant conditional
Thanks,
Jiada
>
> + dev_err(&client->dev, "%s: i2c transfer
> failed (%d)\n",
> + __func__, ret);
> + return ret < 0 ? ret : -EIO;
> + }
> }
>
> - return ret;
> + return 0;
> }
>
>
> Same comments about below.
>
> static int __mxt_write_reg(struct i2c_client *client, u16 reg, u16
> len,
> @@ -661,6 +668,7 @@ static int __mxt_write_reg(struct i2c_client
> *client, u16 reg, u16 len,
> u8 *buf;
> size_t count;
> int ret;
> + bool retry = false;
>
> count = len + 2;
> buf = kmalloc(count, GFP_KERNEL);
> @@ -671,14 +679,21 @@ static int __mxt_write_reg(struct i2c_client
> *client, u16 reg, u16 len,
> buf[1] = (reg >> 8) & 0xff;
> memcpy(&buf[2], val, len);
>
> +retry_write:
> ret = i2c_master_send(client, buf, count);
> - if (ret == count) {
> - ret = 0;
> + if (ret != count) {
> + if (!retry) {
> + dev_dbg(&client->dev, "%s: i2c retry\n",
> __func__);
> + msleep(MXT_WAKEUP_TIME);
> + retry = true;
> + goto retry_write;
> + } else {
> + dev_err(&client->dev, "%s: i2c send failed
> (%d)\n",
> + __func__, ret);
> + ret = ret < 0 ? ret : -EIO;
> + }
> } else {
> - if (ret >= 0)
> - ret = -EIO;
> - dev_err(&client->dev, "%s: i2c send failed (%d)\n",
> - __func__, ret);
> + ret = 0;
> }
>
> kfree(buf);
> --
> 2.17.1
>
>
>
> --
> With Best Regards,
> Andy Shevchenko
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-09-12 0:50 UTC | newest]
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2020-09-03 15:59 [PATCH v2 1/1] Input: atmel_mxt_ts - implement I2C retries Jiada Wang
2020-09-05 14:06 ` Dmitry Osipenko
[not found] ` <CAHp75Vfw1bJ+0pRJKVJ=nCJ-5rVzYLjkP4iWPqiG-it0qp5GFg@mail.gmail.com>
2020-09-05 18:57 ` Dmitry Osipenko
2020-09-12 0:50 ` Wang, Jiada
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