[PATCH v4 0/3] i2c: Use devm_clk_get_enabled() helpers

[PATCH v4 0/3] i2c: Use devm_clk_get_enabled() helpers

[Rong Qianfeng]

The devm_clk_get_enabled() helpers:
    - call devm_clk_get()
    - call clk_prepare_enable() and register what is needed in order to
     call clk_disable_unprepare() when needed, as a managed resource.

This simplifies the code and avoids the calls to clk_disable_unprepare().

-v4:
 *Use struct dev *dev to replace &pdev->dev to further simplify
  the code according to Andy Shevchenko.
 *Use HZ_PER_KHZ to replace 1000 according to Andy Shevchenko.
 *Add or reduce blank lines in some places to make the code more
  compliant as suggested by Andy Shevchenko.

-v3:
 *Add another patch to use dev_err_probe() in jz4780_i2c_probe()
  according to Biju and Paul.

-v2:
 *drop sclk from struct em_i2c_device according to Biju.

Rong Qianfeng (3):
  i2c: emev2: Use devm_clk_get_enabled() helpers
  i2c: jz4780: Use devm_clk_get_enabled() helpers
  i2c: jz4780: Use dev_err_probe()

 drivers/i2c/busses/i2c-emev2.c  | 25 +++++----------
 drivers/i2c/busses/i2c-jz4780.c | 54 ++++++++++++++-------------------
 2 files changed, 31 insertions(+), 48 deletions(-)

-- 
2.39.0

[PATCH v4 1/3] i2c: emev2: Use devm_clk_get_enabled() helpers

[Rong Qianfeng]

The devm_clk_get_enabled() helpers:
    - call devm_clk_get()
    - call clk_prepare_enable() and register what is needed in order to
     call clk_disable_unprepare() when needed, as a managed resource.

This simplifies the code and avoids the calls to clk_disable_unprepare().

While at it, no need to save clk pointer, drop sclk from struct
em_i2c_device.

Signed-off-by: Rong Qianfeng <rongqianfeng@vivo.com>
---
 drivers/i2c/busses/i2c-emev2.c | 25 ++++++++-----------------
 1 file changed, 8 insertions(+), 17 deletions(-)

diff --git a/drivers/i2c/busses/i2c-emev2.c b/drivers/i2c/busses/i2c-emev2.c
index 557409410445..d08be3f3cede 100644
--- a/drivers/i2c/busses/i2c-emev2.c
+++ b/drivers/i2c/busses/i2c-emev2.c
@@ -67,7 +67,6 @@ struct em_i2c_device {
 	void __iomem *base;
 	struct i2c_adapter adap;
 	struct completion msg_done;
-	struct clk *sclk;
 	struct i2c_client *slave;
 	int irq;
 };
@@ -361,6 +360,7 @@ static const struct i2c_algorithm em_i2c_algo = {
 static int em_i2c_probe(struct platform_device *pdev)
 {
 	struct em_i2c_device *priv;
+	struct clk *sclk;
 	int ret;
 
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
@@ -373,13 +373,9 @@ static int em_i2c_probe(struct platform_device *pdev)
 
 	strscpy(priv->adap.name, "EMEV2 I2C", sizeof(priv->adap.name));
 
-	priv->sclk = devm_clk_get(&pdev->dev, "sclk");
-	if (IS_ERR(priv->sclk))
-		return PTR_ERR(priv->sclk);
-
-	ret = clk_prepare_enable(priv->sclk);
-	if (ret)
-		return ret;
+	sclk = devm_clk_get_enabled(&pdev->dev, "sclk");
+	if (IS_ERR(sclk))
+		return PTR_ERR(sclk);
 
 	priv->adap.timeout = msecs_to_jiffies(100);
 	priv->adap.retries = 5;
@@ -397,26 +393,22 @@ static int em_i2c_probe(struct platform_device *pdev)
 
 	ret = platform_get_irq(pdev, 0);
 	if (ret < 0)
-		goto err_clk;
+		return ret;
 	priv->irq = ret;
+
 	ret = devm_request_irq(&pdev->dev, priv->irq, em_i2c_irq_handler, 0,
 				"em_i2c", priv);
 	if (ret)
-		goto err_clk;
+		return ret;
 
 	ret = i2c_add_adapter(&priv->adap);
-
 	if (ret)
-		goto err_clk;
+		return ret;
 
 	dev_info(&pdev->dev, "Added i2c controller %d, irq %d\n", priv->adap.nr,
 		 priv->irq);
 
 	return 0;
-
-err_clk:
-	clk_disable_unprepare(priv->sclk);
-	return ret;
 }
 
 static void em_i2c_remove(struct platform_device *dev)
@@ -424,7 +416,6 @@ static void em_i2c_remove(struct platform_device *dev)
 	struct em_i2c_device *priv = platform_get_drvdata(dev);
 
 	i2c_del_adapter(&priv->adap);
-	clk_disable_unprepare(priv->sclk);
 }
 
 static const struct of_device_id em_i2c_ids[] = {
-- 
2.39.0

Re: [PATCH v4 1/3] i2c: emev2: Use devm_clk_get_enabled() helpers

[Geert Uytterhoeven]

On Tue, Aug 27, 2024 at 5:49 AM Rong Qianfeng <rongqianfeng@vivo.com> wrote:
> The devm_clk_get_enabled() helpers:
>     - call devm_clk_get()
>     - call clk_prepare_enable() and register what is needed in order to
>      call clk_disable_unprepare() when needed, as a managed resource.
>
> This simplifies the code and avoids the calls to clk_disable_unprepare().
>
> While at it, no need to save clk pointer, drop sclk from struct
> em_i2c_device.
>
> Signed-off-by: Rong Qianfeng <rongqianfeng@vivo.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v4 1/3] i2c: emev2: Use devm_clk_get_enabled() helpers

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 576 bytes --]

On Tue, Aug 27, 2024 at 11:48:39AM +0800, Rong Qianfeng wrote:
> The devm_clk_get_enabled() helpers:
>     - call devm_clk_get()
>     - call clk_prepare_enable() and register what is needed in order to
>      call clk_disable_unprepare() when needed, as a managed resource.
> 
> This simplifies the code and avoids the calls to clk_disable_unprepare().
> 
> While at it, no need to save clk pointer, drop sclk from struct
> em_i2c_device.
> 
> Signed-off-by: Rong Qianfeng <rongqianfeng@vivo.com>

Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>


[-- Attachment #2: signature.asc --]
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[PATCH v4 2/3] i2c: jz4780: Use devm_clk_get_enabled() helpers

[Rong Qianfeng]

The devm_clk_get_enabled() helpers:
    - call devm_clk_get()
    - call clk_prepare_enable() and register what is needed in order to
     call clk_disable_unprepare() when needed, as a managed resource.

This simplifies the code and avoids the calls to clk_disable_unprepare().

While at it, no more special handling needed here, remove the goto
label "err:".

Signed-off-by: Rong Qianfeng <rongqianfeng@vivo.com>
Acked-by: Paul Cercueil <paul@crapouillou.net>
---
 drivers/i2c/busses/i2c-jz4780.c | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/drivers/i2c/busses/i2c-jz4780.c b/drivers/i2c/busses/i2c-jz4780.c
index 4aafdfab6305..92cc5b091137 100644
--- a/drivers/i2c/busses/i2c-jz4780.c
+++ b/drivers/i2c/busses/i2c-jz4780.c
@@ -792,26 +792,22 @@ static int jz4780_i2c_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, i2c);
 
-	i2c->clk = devm_clk_get(&pdev->dev, NULL);
+	i2c->clk = devm_clk_get_enabled(&pdev->dev, NULL);
 	if (IS_ERR(i2c->clk))
 		return PTR_ERR(i2c->clk);
 
-	ret = clk_prepare_enable(i2c->clk);
-	if (ret)
-		return ret;
-
 	ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 				   &clk_freq);
 	if (ret) {
 		dev_err(&pdev->dev, "clock-frequency not specified in DT\n");
-		goto err;
+		return ret;
 	}
 
 	i2c->speed = clk_freq / 1000;
 	if (i2c->speed == 0) {
 		ret = -EINVAL;
 		dev_err(&pdev->dev, "clock-frequency minimum is 1000\n");
-		goto err;
+		return ret;
 	}
 	jz4780_i2c_set_speed(i2c);
 
@@ -827,29 +823,25 @@ static int jz4780_i2c_probe(struct platform_device *pdev)
 
 	ret = platform_get_irq(pdev, 0);
 	if (ret < 0)
-		goto err;
+		return ret;
 	i2c->irq = ret;
+
 	ret = devm_request_irq(&pdev->dev, i2c->irq, jz4780_i2c_irq, 0,
 			       dev_name(&pdev->dev), i2c);
 	if (ret)
-		goto err;
+		return ret;
 
 	ret = i2c_add_adapter(&i2c->adap);
 	if (ret < 0)
-		goto err;
+		return ret;
 
 	return 0;
-
-err:
-	clk_disable_unprepare(i2c->clk);
-	return ret;
 }
 
 static void jz4780_i2c_remove(struct platform_device *pdev)
 {
 	struct jz4780_i2c *i2c = platform_get_drvdata(pdev);
 
-	clk_disable_unprepare(i2c->clk);
 	i2c_del_adapter(&i2c->adap);
 }
 
-- 
2.39.0

[PATCH v4 3/3] i2c: jz4780: Use dev_err_probe()

[Rong Qianfeng]

No more special handling needed here, so use dev_err_probe()
to simplify the code.

While at it, use struct dev *dev to replace &pdev->dev to
further simplify the code.

Use the macro definition HZ_PER_KHZ to replace the 1000.

Signed-off-by: Rong Qianfeng <rongqianfeng@vivo.com>
---
 drivers/i2c/busses/i2c-jz4780.c | 40 ++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/drivers/i2c/busses/i2c-jz4780.c b/drivers/i2c/busses/i2c-jz4780.c
index 92cc5b091137..72823a0f39c2 100644
--- a/drivers/i2c/busses/i2c-jz4780.c
+++ b/drivers/i2c/busses/i2c-jz4780.c
@@ -23,6 +23,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/time.h>
+#include <linux/units.h>
 
 #define JZ4780_I2C_CTRL		0x00
 #define JZ4780_I2C_TAR		0x04
@@ -764,14 +765,15 @@ static int jz4780_i2c_probe(struct platform_device *pdev)
 	unsigned int clk_freq = 0;
 	unsigned short tmp;
 	struct jz4780_i2c *i2c;
+	struct device *dev = &pdev->dev;
 
-	i2c = devm_kzalloc(&pdev->dev, sizeof(struct jz4780_i2c), GFP_KERNEL);
+	i2c = devm_kzalloc(dev, sizeof(struct jz4780_i2c), GFP_KERNEL);
 	if (!i2c)
 		return -ENOMEM;
 
-	i2c->cdata = device_get_match_data(&pdev->dev);
+	i2c->cdata = device_get_match_data(dev);
 	if (!i2c->cdata) {
-		dev_err(&pdev->dev, "Error: No device match found\n");
+		dev_err(dev, "Error: No device match found\n");
 		return -ENODEV;
 	}
 
@@ -779,8 +781,8 @@ static int jz4780_i2c_probe(struct platform_device *pdev)
 	i2c->adap.algo		= &jz4780_i2c_algorithm;
 	i2c->adap.algo_data	= i2c;
 	i2c->adap.retries	= 5;
-	i2c->adap.dev.parent	= &pdev->dev;
-	i2c->adap.dev.of_node	= pdev->dev.of_node;
+	i2c->adap.dev.parent	= dev;
+	i2c->adap.dev.of_node	= dev->of_node;
 	sprintf(i2c->adap.name, "%s", pdev->name);
 
 	init_completion(&i2c->trans_waitq);
@@ -792,26 +794,24 @@ static int jz4780_i2c_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, i2c);
 
-	i2c->clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	i2c->clk = devm_clk_get_enabled(dev, NULL);
 	if (IS_ERR(i2c->clk))
 		return PTR_ERR(i2c->clk);
 
-	ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+	ret = of_property_read_u32(dev->of_node, "clock-frequency",
 				   &clk_freq);
-	if (ret) {
-		dev_err(&pdev->dev, "clock-frequency not specified in DT\n");
-		return ret;
-	}
+	if (ret)
+		return dev_err_probe(dev, ret,
+					"clock-frequency not specified in DT\n");
+
+	i2c->speed = clk_freq / HZ_PER_KHZ;
+	if (i2c->speed == 0)
+		return dev_err_probe(dev, -EINVAL,
+					"clock-frequency minimum is HZ_PER_KHZ\n");
 
-	i2c->speed = clk_freq / 1000;
-	if (i2c->speed == 0) {
-		ret = -EINVAL;
-		dev_err(&pdev->dev, "clock-frequency minimum is 1000\n");
-		return ret;
-	}
 	jz4780_i2c_set_speed(i2c);
 
-	dev_info(&pdev->dev, "Bus frequency is %d KHz\n", i2c->speed);
+	dev_info(dev, "Bus frequency is %d KHz\n", i2c->speed);
 
 	if (i2c->cdata->version < ID_X1000) {
 		tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
@@ -826,8 +826,8 @@ static int jz4780_i2c_probe(struct platform_device *pdev)
 		return ret;
 	i2c->irq = ret;
 
-	ret = devm_request_irq(&pdev->dev, i2c->irq, jz4780_i2c_irq, 0,
-			       dev_name(&pdev->dev), i2c);
+	ret = devm_request_irq(dev, i2c->irq, jz4780_i2c_irq, 0,
+			       dev_name(dev), i2c);
 	if (ret)
 		return ret;
 
-- 
2.39.0

Re: [PATCH v4 3/3] i2c: jz4780: Use dev_err_probe()

[Andi Shyti]

Hi Rong,

On Tue, Aug 27, 2024 at 11:48:41AM GMT, Rong Qianfeng wrote:
> No more special handling needed here, so use dev_err_probe()
> to simplify the code.
> 
> While at it, use struct dev *dev to replace &pdev->dev to
> further simplify the code.
> 
> Use the macro definition HZ_PER_KHZ to replace the 1000.
> 
> Signed-off-by: Rong Qianfeng <rongqianfeng@vivo.com>
> ---
>  drivers/i2c/busses/i2c-jz4780.c | 40 ++++++++++++++++-----------------
>  1 file changed, 20 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-jz4780.c b/drivers/i2c/busses/i2c-jz4780.c
> index 92cc5b091137..72823a0f39c2 100644
> --- a/drivers/i2c/busses/i2c-jz4780.c
> +++ b/drivers/i2c/busses/i2c-jz4780.c
> @@ -23,6 +23,7 @@
>  #include <linux/sched.h>
>  #include <linux/slab.h>
>  #include <linux/time.h>
> +#include <linux/units.h>
>  
>  #define JZ4780_I2C_CTRL		0x00
>  #define JZ4780_I2C_TAR		0x04
> @@ -764,14 +765,15 @@ static int jz4780_i2c_probe(struct platform_device *pdev)
>  	unsigned int clk_freq = 0;
>  	unsigned short tmp;
>  	struct jz4780_i2c *i2c;
> +	struct device *dev = &pdev->dev;

I'm not a big fan of this change. There is not much gain in
polluting git bisect in order to shorten pdev->dev to a single
dev.

However, I like the /dev_err/dev_err_probe/.

I will take the first two patches from this series, but I will
leave this if anyone else has a stronger opinion. If you want,
you can send just this one patch with just the dev_err_probe()
change.

Thanks,
Andi

Re: [PATCH v4 3/3] i2c: jz4780: Use dev_err_probe()

[Rong Qianfeng]

Hi Andi,

> I'm not a big fan of this change. There is not much gain in
> polluting git bisect in order to shorten pdev->dev to a single
> dev.
>
> However, I like the /dev_err/dev_err_probe/.
>
> I will take the first two patches from this series, but I will
> leave this if anyone else has a stronger opinion. If you want,
> you can send just this one patch with just the dev_err_probe()
> change.
Thanks for taking the time to review my patch!
Please take the first two patches, I don't plan to submit another
patch that only modifies dev_err().

Best Regards,
Qianfeng

Re: [PATCH v4 3/3] i2c: jz4780: Use dev_err_probe()

[Andi Shyti]

Hi Rong,

On Mon, Sep 09, 2024 at 04:58:10PM GMT, Rong Qianfeng wrote:
> > I'm not a big fan of this change. There is not much gain in
> > polluting git bisect in order to shorten pdev->dev to a single
> > dev.
> > 
> > However, I like the /dev_err/dev_err_probe/.
> > 
> > I will take the first two patches from this series, but I will
> > leave this if anyone else has a stronger opinion. If you want,
> > you can send just this one patch with just the dev_err_probe()
> > change.
> Thanks for taking the time to review my patch!
> Please take the first two patches, I don't plan to submit another
> patch that only modifies dev_err().

Sorry, I forgot to write it, I merged the first two in
i2c/i2c-host.

If you want to send one to change dev_err with dev_err_probe
separately I will take it.

Thanks,
Andi

Re: [PATCH v4 3/3] i2c: jz4780: Use dev_err_probe()

[Rong Qianfeng]

Hi Andi,

在 2024/9/10 3:24, Andi Shyti 写道:
> On Mon, Sep 09, 2024 at 04:58:10PM GMT, Rong Qianfeng wrote:
>>> I'm not a big fan of this change. There is not much gain in
>>> polluting git bisect in order to shorten pdev->dev to a single
>>> dev.
>>>
>>> However, I like the /dev_err/dev_err_probe/.
>>>
>>> I will take the first two patches from this series, but I will
>>> leave this if anyone else has a stronger opinion. If you want,
>>> you can send just this one patch with just the dev_err_probe()
>>> change.
>> Thanks for taking the time to review my patch!
>> Please take the first two patches, I don't plan to submit another
>> patch that only modifies dev_err().
> Sorry, I forgot to write it, I merged the first two in
> i2c/i2c-host.
>
> If you want to send one to change dev_err with dev_err_probe
> separately I will take it.

ok, I got it, thanks.

Best Regards,
Qianfeng

Re: [PATCH v4 3/3] i2c: jz4780: Use dev_err_probe()

[Andy Shevchenko]

On Mon, Sep 09, 2024 at 10:23:30AM +0200, Andi Shyti wrote:
> On Tue, Aug 27, 2024 at 11:48:41AM GMT, Rong Qianfeng wrote:

...

> > +	struct device *dev = &pdev->dev;
> 
> I'm not a big fan of this change. There is not much gain in
> polluting git bisect in order to shorten pdev->dev to a single
> dev.
> 
> However, I like the /dev_err/dev_err_probe/.
> 
> I will take the first two patches from this series, but I will
> leave this if anyone else has a stronger opinion. If you want,
> you can send just this one patch with just the dev_err_probe()
> change.

Usually I combined this with conversion to dev_err_probe() et al.
so it makes new lines a bit shorter and hence readability a bit better.
On its own it's indeed questionable change.

-- 
With Best Regards,
Andy Shevchenko