diff mbox series

[1/3] i2c: add init_recovery() callback

Message ID 20250511-i2c-pxa-fix-i2c-communication-v1-1-e9097d09a015@gmail.com
State New
Headers show
Series [1/3] i2c: add init_recovery() callback | expand

Commit Message

Gabor Juhos May 11, 2025, 1:31 p.m. UTC 
Add a new init_recovery() callback to struct 'i2c_bus_recovery_info'
and modify the i2c_init_recovery() function to call that if specified
instead of the generic i2c_gpio_init_recovery() function.

This allows controller drivers to skip calling the generic code by
implementing a dummy callback function, or alternatively to run a
fine tuned custom implementation.

This is needed for the 'i2c-pxa' driver in order to be able to fix
a long standing bug for which the fix will be implemented in a
followup patch.

Cc: stable@vger.kernel.org # 6.3+
Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
---
 drivers/i2c/i2c-core-base.c | 8 +++++++-
 include/linux/i2c.h         | 4 ++++
 2 files changed, 11 insertions(+), 1 deletion(-)

Comments

Linus Walleij May 13, 2025, 1:32 p.m. UTC | #1 
Szía Gabor,

köszönöm a patch-et!

On Sun, May 11, 2025 at 3:31 PM Gabor Juhos <j4g8y7@gmail.com> wrote:

> Add a new init_recovery() callback to struct 'i2c_bus_recovery_info'
> and modify the i2c_init_recovery() function to call that if specified
> instead of the generic i2c_gpio_init_recovery() function.
>
> This allows controller drivers to skip calling the generic code by
> implementing a dummy callback function, or alternatively to run a
> fine tuned custom implementation.
>
> This is needed for the 'i2c-pxa' driver in order to be able to fix
> a long standing bug for which the fix will be implemented in a
> followup patch.
>
> Cc: stable@vger.kernel.org # 6.3+
> Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
> Signed-off-by: Imre Kaloz <kaloz@openwrt.org>

Clearly, since the same problems keeps appearing on other
platforms as well, this is the right way to go!
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij
diff mbox series

Patch

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 7ad1ad5c8c3f56943b627254b1fdbf8f787afdb5..6b8b961b845caf6f28ea1a9a76d623ac73f5e0dd 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -427,12 +427,18 @@  static int i2c_init_recovery(struct i2c_adapter *adap)
 	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
 	bool is_error_level = true;
 	char *err_str;
+	int ret;
 
 	if (!bri)
 		return 0;
 
-	if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER)
+	if (bri->init_recovery) {
+		ret = bri->init_recovery(adap);
+		if (ret)
+			return ret;
+	} else if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER) {
 		return -EPROBE_DEFER;
+	}
 
 	if (!bri->recover_bus) {
 		err_str = "no suitable method provided";
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 2e4903b7f7bc11627f9cbc23a4d549dd48c4dcc7..1cff399822c817429e520572546a3d0b7f704723 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -638,6 +638,9 @@  struct i2c_timings {
  *	for generic GPIO recovery.
  * @get_bus_free: Returns the bus free state as seen from the IP core in case it
  *	has a more complex internal logic than just reading SDA. Optional.
+ * @init_recovery: If specified, it will be called instead of the generic GPIO
+ *	recovery initialization code. Platform may use a dummy callback to skip
+ *	calling the generic code, or it may use a custom implementation.
  * @prepare_recovery: This will be called before starting recovery. Platform may
  *	configure padmux here for SDA/SCL line or something else they want.
  * @unprepare_recovery: This will be called after completing recovery. Platform
@@ -662,6 +665,7 @@  struct i2c_bus_recovery_info {
 	void (*set_sda)(struct i2c_adapter *adap, int val);
 	int (*get_bus_free)(struct i2c_adapter *adap);
 
+	int (*init_recovery)(struct i2c_adapter *adap);
 	void (*prepare_recovery)(struct i2c_adapter *adap);
 	void (*unprepare_recovery)(struct i2c_adapter *adap);