[PATCH v2] rtc: pcf8563: add SMBus support

[PATCH v2] rtc: pcf8563: add SMBus support

[Michael Walle]

Since commit 00f1bb9b8486 ("rtc: pcf8563: Switch to regmap") the driver
uses regmap to access the RTC. Regmap itself will figure out if there is
a suitable I2C or SMBus host controllers. Thus, don't restict the driver
to just I2C controllers and make it work on SMBus controllers supporting
i2c block accesses, too.

This was tested on a custom x86 board.

Signed-off-by: Michael Walle <mwalle@kernel.org>
---
 drivers/rtc/rtc-pcf8563.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
index 7eebdb058067..56e75664c7b4 100644
--- a/drivers/rtc/rtc-pcf8563.c
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -479,7 +479,8 @@ static int pcf8563_probe(struct i2c_client *client)
 
 	dev_dbg(&client->dev, "%s\n", __func__);
 
-	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C) &&
+	    !i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
 		return -ENODEV;
 
 	pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
-- 
2.47.3

Re: [PATCH v2] rtc: pcf8563: add SMBus support

[Michael Walle]

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On Thu Oct 8, 2026 at 9:13 AM CEST, Michael Walle wrote:
> Since commit 00f1bb9b8486 ("rtc: pcf8563: Switch to regmap") the driver
> uses regmap to access the RTC. Regmap itself will figure out if there is
> a suitable I2C or SMBus host controllers. Thus, don't restict the driver
> to just I2C controllers and make it work on SMBus controllers supporting
> i2c block accesses, too.
>
> This was tested on a custom x86 board.
>
> Signed-off-by: Michael Walle <mwalle@kernel.org>
> ---

Sorry forgot the changelog:

v2:
 - instead of dropping the check altogether, check for either i2c or
   smbus block support.

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Re: [PATCH v2] rtc: pcf8563: add SMBus support

[sashiko-bot]

> Since commit 00f1bb9b8486 ("rtc: pcf8563: Switch to regmap") the driver
> uses regmap to access the RTC. Regmap itself will figure out if there is
> a suitable I2C or SMBus host controllers. Thus, don't restict the driver
> to just I2C controllers and make it work on SMBus controllers supporting
> i2c block accesses, too.
> 
> This was tested on a custom x86 board.
> 
> Signed-off-by: Michael Walle <mwalle@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261008071408.3548442-1-mwalle@kernel.org?part=1

Re: [PATCH v2] rtc: pcf8563: add SMBus support

[Alexandre Belloni]

On Thu, 08 Oct 2026 09:13:05 +0200, Michael Walle wrote:
> Since commit 00f1bb9b8486 ("rtc: pcf8563: Switch to regmap") the driver
> uses regmap to access the RTC. Regmap itself will figure out if there is
> a suitable I2C or SMBus host controllers. Thus, don't restict the driver
> to just I2C controllers and make it work on SMBus controllers supporting
> i2c block accesses, too.
> 
> This was tested on a custom x86 board.
> 
> [...]

Applied, thanks!

[1/1] rtc: pcf8563: add SMBus support
      https://git.kernel.org/abelloni/c/237378fd6be4

Best regards,

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com