[PATCH v1 1/2] serial: 8250_dw: Use devm_add_action_or_reset()

[PATCH v1 1/2] serial: 8250_dw: Use devm_add_action_or_reset()

[Andy Shevchenko]

Slightly simplify ->probe() and drop a few goto labels by using
devm_add_action_or_reset() for clock and reset cleanup.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/tty/serial/8250/8250_dw.c | 63 +++++++++++++++----------------
 1 file changed, 31 insertions(+), 32 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 7934e4658281..e7ef61899576 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -484,6 +484,16 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 	}
 }
 
+static void dw8250_clk_disable_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static void dw8250_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
 static int dw8250_probe(struct platform_device *pdev)
 {
 	struct uart_8250_port uart = {}, *up = &uart;
@@ -585,35 +595,43 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (err)
 		dev_warn(dev, "could not enable optional baudclk: %d\n", err);
 
+	err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->clk);
+	if (err)
+		return err;
+
 	if (data->clk)
 		p->uartclk = clk_get_rate(data->clk);
 
 	/* If no clock rate is defined, fail. */
 	if (!p->uartclk) {
 		dev_err(dev, "clock rate not defined\n");
-		err = -EINVAL;
-		goto err_clk;
+		return -EINVAL;
 	}
 
 	data->pclk = devm_clk_get_optional(dev, "apb_pclk");
-	if (IS_ERR(data->pclk)) {
-		err = PTR_ERR(data->pclk);
-		goto err_clk;
-	}
+	if (IS_ERR(data->pclk))
+		return PTR_ERR(data->pclk);
 
 	err = clk_prepare_enable(data->pclk);
 	if (err) {
 		dev_err(dev, "could not enable apb_pclk\n");
-		goto err_clk;
+		return err;
 	}
 
+	err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->pclk);
+	if (err)
+		return err;
+
 	data->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
-	if (IS_ERR(data->rst)) {
-		err = PTR_ERR(data->rst);
-		goto err_pclk;
-	}
+	if (IS_ERR(data->rst))
+		return PTR_ERR(data->rst);
+
 	reset_control_deassert(data->rst);
 
+	err = devm_add_action_or_reset(dev, dw8250_reset_control_assert, data->rst);
+	if (err)
+		return err;
+
 	dw8250_quirks(p, data);
 
 	/* If the Busy Functionality is not implemented, don't handle it */
@@ -631,10 +649,8 @@ static int dw8250_probe(struct platform_device *pdev)
 	}
 
 	data->data.line = serial8250_register_8250_port(up);
-	if (data->data.line < 0) {
-		err = data->data.line;
-		goto err_reset;
-	}
+	if (data->data.line < 0)
+		return data->data.line;
 
 	/*
 	 * Some platforms may provide a reference clock shared between several
@@ -655,17 +671,6 @@ static int dw8250_probe(struct platform_device *pdev)
 	pm_runtime_enable(dev);
 
 	return 0;
-
-err_reset:
-	reset_control_assert(data->rst);
-
-err_pclk:
-	clk_disable_unprepare(data->pclk);
-
-err_clk:
-	clk_disable_unprepare(data->clk);
-
-	return err;
 }
 
 static int dw8250_remove(struct platform_device *pdev)
@@ -683,12 +688,6 @@ static int dw8250_remove(struct platform_device *pdev)
 
 	serial8250_unregister_port(data->data.line);
 
-	reset_control_assert(data->rst);
-
-	clk_disable_unprepare(data->pclk);
-
-	clk_disable_unprepare(data->clk);
-
 	pm_runtime_disable(dev);
 	pm_runtime_put_noidle(dev);
 
-- 
2.35.1

[PATCH v1 2/2] serial: 8250_dw: Use dev_err_probe()

[Andy Shevchenko]

Simplify the error path in ->probe() a bit by using dev_err_probe().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/tty/serial/8250/8250_dw.c | 28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index e7ef61899576..f57bbd32ef11 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -497,18 +497,17 @@ static void dw8250_reset_control_assert(void *data)
 static int dw8250_probe(struct platform_device *pdev)
 {
 	struct uart_8250_port uart = {}, *up = &uart;
-	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	struct uart_port *p = &up->port;
 	struct device *dev = &pdev->dev;
 	struct dw8250_data *data;
+	struct resource *regs;
 	int irq;
 	int err;
 	u32 val;
 
-	if (!regs) {
-		dev_err(dev, "no registers defined\n");
-		return -EINVAL;
-	}
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs)
+		return dev_err_probe(dev, -EINVAL, "no registers defined\n");
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
@@ -593,7 +592,7 @@ static int dw8250_probe(struct platform_device *pdev)
 
 	err = clk_prepare_enable(data->clk);
 	if (err)
-		dev_warn(dev, "could not enable optional baudclk: %d\n", err);
+		return dev_err_probe(dev, err, "could not enable optional baudclk\n");
 
 	err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->clk);
 	if (err)
@@ -603,20 +602,16 @@ static int dw8250_probe(struct platform_device *pdev)
 		p->uartclk = clk_get_rate(data->clk);
 
 	/* If no clock rate is defined, fail. */
-	if (!p->uartclk) {
-		dev_err(dev, "clock rate not defined\n");
-		return -EINVAL;
-	}
+	if (!p->uartclk)
+		return dev_err_probe(dev, -EINVAL, "clock rate not defined\n");
 
 	data->pclk = devm_clk_get_optional(dev, "apb_pclk");
 	if (IS_ERR(data->pclk))
 		return PTR_ERR(data->pclk);
 
 	err = clk_prepare_enable(data->pclk);
-	if (err) {
-		dev_err(dev, "could not enable apb_pclk\n");
-		return err;
-	}
+	if (err)
+		return dev_err_probe(dev, err, "could not enable apb_pclk\n");
 
 	err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->pclk);
 	if (err)
@@ -660,9 +655,8 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (data->clk) {
 		err = clk_notifier_register(data->clk, &data->clk_notifier);
 		if (err)
-			dev_warn(p->dev, "Failed to set the clock notifier\n");
-		else
-			queue_work(system_unbound_wq, &data->clk_work);
+			return dev_err_probe(dev, err, "Failed to set the clock notifier\n");
+		queue_work(system_unbound_wq, &data->clk_work);
 	}
 
 	platform_set_drvdata(pdev, data);
-- 
2.35.1

Re: [PATCH v1 1/2] serial: 8250_dw: Use devm_add_action_or_reset()

[Christophe JAILLET]

Le 09/05/2022 à 19:21, Andy Shevchenko a écrit :
> Slightly simplify ->probe() and drop a few goto labels by using
> devm_add_action_or_reset() for clock and reset cleanup.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>   drivers/tty/serial/8250/8250_dw.c | 63 +++++++++++++++----------------
>   1 file changed, 31 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
> index 7934e4658281..e7ef61899576 100644
> --- a/drivers/tty/serial/8250/8250_dw.c
> +++ b/drivers/tty/serial/8250/8250_dw.c
> @@ -484,6 +484,16 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
>   	}
>   }
>   
> +static void dw8250_clk_disable_unprepare(void *data)
> +{
> +	clk_disable_unprepare(data);
> +}

Hi,

we already have several time this function in different drivers.
Maybe, it would be nice to have something standart for it.

A devm_clk_prepare_enable() or something devm-helpers.h ([1])

Just my 2c.

CJ

[1]: 
https://elixir.bootlin.com/linux/v5.18-rc6/source/include/linux/devm-helpers.h

> +
> +static void dw8250_reset_control_assert(void *data)
> +{
> +	reset_control_assert(data);
> +}
> +
>   static int dw8250_probe(struct platform_device *pdev)
>   {
>   	struct uart_8250_port uart = {}, *up = &uart;
> @@ -585,35 +595,43 @@ static int dw8250_probe(struct platform_device *pdev)
>   	if (err)
>   		dev_warn(dev, "could not enable optional baudclk: %d\n", err);
>   
> +	err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->clk);
> +	if (err)
> +		return err;
> +
>   	if (data->clk)
>   		p->uartclk = clk_get_rate(data->clk);
>   
>   	/* If no clock rate is defined, fail. */
>   	if (!p->uartclk) {
>   		dev_err(dev, "clock rate not defined\n");
> -		err = -EINVAL;
> -		goto err_clk;
> +		return -EINVAL;
>   	}
>   
>   	data->pclk = devm_clk_get_optional(dev, "apb_pclk");
> -	if (IS_ERR(data->pclk)) {
> -		err = PTR_ERR(data->pclk);
> -		goto err_clk;
> -	}
> +	if (IS_ERR(data->pclk))
> +		return PTR_ERR(data->pclk);
>   
>   	err = clk_prepare_enable(data->pclk);
>   	if (err) {
>   		dev_err(dev, "could not enable apb_pclk\n");
> -		goto err_clk;
> +		return err;
>   	}
>   
> +	err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->pclk);
> +	if (err)
> +		return err;
> +
>   	data->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
> -	if (IS_ERR(data->rst)) {
> -		err = PTR_ERR(data->rst);
> -		goto err_pclk;
> -	}
> +	if (IS_ERR(data->rst))
> +		return PTR_ERR(data->rst);
> +
>   	reset_control_deassert(data->rst);
>   
> +	err = devm_add_action_or_reset(dev, dw8250_reset_control_assert, data->rst);
> +	if (err)
> +		return err;
> +
>   	dw8250_quirks(p, data);
>   
>   	/* If the Busy Functionality is not implemented, don't handle it */
> @@ -631,10 +649,8 @@ static int dw8250_probe(struct platform_device *pdev)
>   	}
>   
>   	data->data.line = serial8250_register_8250_port(up);
> -	if (data->data.line < 0) {
> -		err = data->data.line;
> -		goto err_reset;
> -	}
> +	if (data->data.line < 0)
> +		return data->data.line;
>   
>   	/*
>   	 * Some platforms may provide a reference clock shared between several
> @@ -655,17 +671,6 @@ static int dw8250_probe(struct platform_device *pdev)
>   	pm_runtime_enable(dev);
>   
>   	return 0;
> -
> -err_reset:
> -	reset_control_assert(data->rst);
> -
> -err_pclk:
> -	clk_disable_unprepare(data->pclk);
> -
> -err_clk:
> -	clk_disable_unprepare(data->clk);
> -
> -	return err;
>   }
>   
>   static int dw8250_remove(struct platform_device *pdev)
> @@ -683,12 +688,6 @@ static int dw8250_remove(struct platform_device *pdev)
>   
>   	serial8250_unregister_port(data->data.line);
>   
> -	reset_control_assert(data->rst);
> -
> -	clk_disable_unprepare(data->pclk);
> -
> -	clk_disable_unprepare(data->clk);
> -
>   	pm_runtime_disable(dev);
>   	pm_runtime_put_noidle(dev);
>   

Re: [PATCH v1 1/2] serial: 8250_dw: Use devm_add_action_or_reset()

[Andy Shevchenko]

On Mon, May 9, 2022 at 7:49 PM Christophe JAILLET
<christophe.jaillet@wanadoo.fr> wrote:
> Le 09/05/2022 à 19:21, Andy Shevchenko a écrit :

...

> > +static void dw8250_clk_disable_unprepare(void *data)
> > +{
> > +     clk_disable_unprepare(data);
> > +}

> we already have several time this function in different drivers.
> Maybe, it would be nice to have something standart for it.
>
> A devm_clk_prepare_enable() or something devm-helpers.h ([1])

Seems you missed the full story. We tried to add that several times
[1] and CCF maintainers refused all the time. You may work with them
to convince them.

[1]: https://lore.kernel.org/linux-clk/20210304221247.488173-2-linux@rasmusvillemoes.dk/
(the latest one AFAIK)

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 1/2] serial: 8250_dw: Use devm_add_action_or_reset()

[Marion & Christophe JAILLET]

Le 09/05/2022 à 19:59, Andy Shevchenko a écrit :
> On Mon, May 9, 2022 at 7:49 PM Christophe JAILLET
> <christophe.jaillet@wanadoo.fr> wrote:
>> Le 09/05/2022 à 19:21, Andy Shevchenko a écrit :
> ...
>
>>> +static void dw8250_clk_disable_unprepare(void *data)
>>> +{
>>> +     clk_disable_unprepare(data);
>>> +}
>> we already have several time this function in different drivers.
>> Maybe, it would be nice to have something standart for it.
>>
>> A devm_clk_prepare_enable() or something devm-helpers.h ([1])
> Seems you missed the full story. We tried to add that several times
> [1] and CCF maintainers refused all the time. You may work with them
> to convince them.
>
> [1]: https://lore.kernel.org/linux-clk/20210304221247.488173-2-linux@rasmusvillemoes.dk/
> (the latest one AFAIK)
>
LoL, got it.

Sorry for the noise.

CJ