[PATCH 0/2] bus: ts-nbus: Two improvements

[PATCH 0/2] bus: ts-nbus: Two improvements

[Uwe Kleine-König]

Hello,

while looking at the few last users of pwm_config() I found this driver
to be easily convertible to the atomic API. The second change is another
patch opportunity I noticed while modifying this driver.

Best regards
Uwe

Uwe Kleine-König (2):
  bus: ts-nbus: Convert to atomic pwm API
  bus: ts-nbus: Improve error reporting

 drivers/bus/ts-nbus.c | 80 ++++++++++++++++++-------------------------
 1 file changed, 33 insertions(+), 47 deletions(-)

base-commit: bc63de6e6ba0b16652c5fb4b9c9916b9e7ca1f23
-- 
2.42.0

[PATCH 1/2] bus: ts-nbus: Convert to atomic pwm API

[Uwe Kleine-König]

With this change the PWM hardware is only configured once (instead of
three times.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/bus/ts-nbus.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/bus/ts-nbus.c b/drivers/bus/ts-nbus.c
index 4fa932cb0915..19c5d1f4e4d7 100644
--- a/drivers/bus/ts-nbus.c
+++ b/drivers/bus/ts-nbus.c
@@ -273,7 +273,7 @@ EXPORT_SYMBOL_GPL(ts_nbus_write);
 static int ts_nbus_probe(struct platform_device *pdev)
 {
 	struct pwm_device *pwm;
-	struct pwm_args pargs;
+	struct pwm_state state;
 	struct device *dev = &pdev->dev;
 	struct ts_nbus *ts_nbus;
 	int ret;
@@ -296,25 +296,22 @@ static int ts_nbus_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	pwm_get_args(pwm, &pargs);
-	if (!pargs.period) {
+	pwm_init_state(pwm, &state);
+	if (!state.period) {
 		dev_err(&pdev->dev, "invalid PWM period\n");
 		return -EINVAL;
 	}
 
-	/*
-	 * FIXME: pwm_apply_args() should be removed when switching to
-	 * the atomic PWM API.
-	 */
-	pwm_apply_args(pwm);
-	ret = pwm_config(pwm, pargs.period, pargs.period);
+	state.duty_cycle = state.period;
+	state.enabled = true;
+
+	ret = pwm_apply_state(pwm, &state);
 	if (ret < 0)
 		return ret;
 
 	/*
 	 * we can now start the FPGA and populate the peripherals.
 	 */
-	pwm_enable(pwm);
 	ts_nbus->pwm = pwm;
 
 	/*
-- 
2.42.0

[PATCH 2/2] bus: ts-nbus: Improve error reporting

[Uwe Kleine-König]

Using dev_err_probe() brings several improvements:

 - emits the symbolic error code
 - properly handles EPROBE_DEFER
 - combines error message generation and return value handling

While at it add error messages to two error paths that were silent
before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/bus/ts-nbus.c | 65 ++++++++++++++++++-------------------------
 1 file changed, 27 insertions(+), 38 deletions(-)

diff --git a/drivers/bus/ts-nbus.c b/drivers/bus/ts-nbus.c
index 19c5d1f4e4d7..89c6ce1403e3 100644
--- a/drivers/bus/ts-nbus.c
+++ b/drivers/bus/ts-nbus.c
@@ -39,45 +39,39 @@ struct ts_nbus {
 /*
  * request all gpios required by the bus.
  */
-static int ts_nbus_init_pdata(struct platform_device *pdev, struct ts_nbus
-		*ts_nbus)
+static int ts_nbus_init_pdata(struct platform_device *pdev,
+			      struct ts_nbus *ts_nbus)
 {
 	ts_nbus->data = devm_gpiod_get_array(&pdev->dev, "ts,data",
 			GPIOD_OUT_HIGH);
-	if (IS_ERR(ts_nbus->data)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,data-gpio from dts\n");
-		return PTR_ERR(ts_nbus->data);
-	}
+	if (IS_ERR(ts_nbus->data))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->data),
+				     "failed to retrieve ts,data-gpio from dts\n");
 
 	ts_nbus->csn = devm_gpiod_get(&pdev->dev, "ts,csn", GPIOD_OUT_HIGH);
-	if (IS_ERR(ts_nbus->csn)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,csn-gpio from dts\n");
-		return PTR_ERR(ts_nbus->csn);
-	}
+	if (IS_ERR(ts_nbus->csn))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->csn),
+			      "failed to retrieve ts,csn-gpio from dts\n");
 
 	ts_nbus->txrx = devm_gpiod_get(&pdev->dev, "ts,txrx", GPIOD_OUT_HIGH);
-	if (IS_ERR(ts_nbus->txrx)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,txrx-gpio from dts\n");
-		return PTR_ERR(ts_nbus->txrx);
-	}
+	if (IS_ERR(ts_nbus->txrx))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->txrx),
+				     "failed to retrieve ts,txrx-gpio from dts\n");
 
 	ts_nbus->strobe = devm_gpiod_get(&pdev->dev, "ts,strobe", GPIOD_OUT_HIGH);
-	if (IS_ERR(ts_nbus->strobe)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,strobe-gpio from dts\n");
-		return PTR_ERR(ts_nbus->strobe);
-	}
+	if (IS_ERR(ts_nbus->strobe))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->strobe),
+				     "failed to retrieve ts,strobe-gpio from dts\n");
 
 	ts_nbus->ale = devm_gpiod_get(&pdev->dev, "ts,ale", GPIOD_OUT_HIGH);
-	if (IS_ERR(ts_nbus->ale)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,ale-gpio from dts\n");
-		return PTR_ERR(ts_nbus->ale);
-	}
+	if (IS_ERR(ts_nbus->ale))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->ale),
+				     "failed to retrieve ts,ale-gpio from dts\n");
 
 	ts_nbus->rdy = devm_gpiod_get(&pdev->dev, "ts,rdy", GPIOD_IN);
-	if (IS_ERR(ts_nbus->rdy)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,rdy-gpio from dts\n");
-		return PTR_ERR(ts_nbus->rdy);
-	}
+	if (IS_ERR(ts_nbus->rdy))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->rdy),
+				     "failed to retrieve ts,rdy-gpio from dts\n");
 
 	return 0;
 }
@@ -289,25 +283,19 @@ static int ts_nbus_probe(struct platform_device *pdev)
 		return ret;
 
 	pwm = devm_pwm_get(dev, NULL);
-	if (IS_ERR(pwm)) {
-		ret = PTR_ERR(pwm);
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "unable to request PWM\n");
-		return ret;
-	}
+	if (IS_ERR(pwm))
+		return dev_err_probe(dev, ret, "unable to request PWM\n");
 
 	pwm_init_state(pwm, &state);
-	if (!state.period) {
-		dev_err(&pdev->dev, "invalid PWM period\n");
-		return -EINVAL;
-	}
+	if (!state.period)
+		return dev_err_probe(dev, -EINVAL, "invalid PWM period\n");
 
 	state.duty_cycle = state.period;
 	state.enabled = true;
 
 	ret = pwm_apply_state(pwm, &state);
 	if (ret < 0)
-		return ret;
+		return dev_err_probe(dev, ret, "failed to configure PWM\n");
 
 	/*
 	 * we can now start the FPGA and populate the peripherals.
@@ -321,7 +309,8 @@ static int ts_nbus_probe(struct platform_device *pdev)
 
 	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
 	if (ret < 0)
-		return ret;
+		return dev_err_probe(dev, ret,
+				     "failed to populate platform devices on bus\n");
 
 	dev_info(dev, "initialized\n");
 
-- 
2.42.0

Re: [PATCH 2/2] bus: ts-nbus: Improve error reporting

[Christophe JAILLET]

Le 09/12/2023 à 23:35, Uwe Kleine-König a écrit :
> Using dev_err_probe() brings several improvements:
> 
>   - emits the symbolic error code
>   - properly handles EPROBE_DEFER
>   - combines error message generation and return value handling
> 
> While at it add error messages to two error paths that were silent
> before.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>   drivers/bus/ts-nbus.c | 65 ++++++++++++++++++-------------------------
>   1 file changed, 27 insertions(+), 38 deletions(-)
> 
> diff --git a/drivers/bus/ts-nbus.c b/drivers/bus/ts-nbus.c

...

> @@ -289,25 +283,19 @@ static int ts_nbus_probe(struct platform_device *pdev)
>   		return ret;
>   
>   	pwm = devm_pwm_get(dev, NULL);
> -	if (IS_ERR(pwm)) {
> -		ret = PTR_ERR(pwm);
> -		if (ret != -EPROBE_DEFER)
> -			dev_err(dev, "unable to request PWM\n");
> -		return ret;
> -	}
> +	if (IS_ERR(pwm))
> +		return dev_err_probe(dev, ret, "unable to request PWM\n");

s/ret/PTR_ERR(pwm)/

CJ

Re: [PATCH 2/2] bus: ts-nbus: Improve error reporting

[Uwe Kleine-König]

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Hello,

[dropped Sebastien from Cc, the address doesn't work]

On Sun, Dec 10, 2023 at 07:55:02AM +0100, Christophe JAILLET wrote:
> Le 09/12/2023 à 23:35, Uwe Kleine-König a écrit :
> > Using dev_err_probe() brings several improvements:
> > 
> >   - emits the symbolic error code
> >   - properly handles EPROBE_DEFER
> >   - combines error message generation and return value handling
> > 
> > While at it add error messages to two error paths that were silent
> > before.
> > 
> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> > ---
> >   drivers/bus/ts-nbus.c | 65 ++++++++++++++++++-------------------------
> >   1 file changed, 27 insertions(+), 38 deletions(-)
> > 
> > diff --git a/drivers/bus/ts-nbus.c b/drivers/bus/ts-nbus.c
> 
> ...
> 
> > @@ -289,25 +283,19 @@ static int ts_nbus_probe(struct platform_device *pdev)
> >   		return ret;
> >   	pwm = devm_pwm_get(dev, NULL);
> > -	if (IS_ERR(pwm)) {
> > -		ret = PTR_ERR(pwm);
> > -		if (ret != -EPROBE_DEFER)
> > -			dev_err(dev, "unable to request PWM\n");
> > -		return ret;
> > -	}
> > +	if (IS_ERR(pwm))
> > +		return dev_err_probe(dev, ret, "unable to request PWM\n");
> 
> s/ret/PTR_ERR(pwm)/

Indeed. Thanks for spotting that. Will send a v2 after waiting a bit
more for feedback.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

[PATCH 2/2] bus: ts-nbus: Improve error reporting

[Uwe Kleine-König]

Using dev_err_probe() brings several improvements:

 - emits the symbolic error code
 - properly handles EPROBE_DEFER
 - combines error message generation and return value handling

While at it add error messages to two error paths that were silent
before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
Changes since (implicit) v1
(https://lore.kernel.org/linux-kernel/20702efe8ab96add9773e97ceed1a6cf91a065ee.1702160838.git.u.kleine-koenig@pengutronix.de):

- Fix return value in one error path (Christophe JAILLET)
- Rebase to today's next (trivial)

 drivers/bus/ts-nbus.c | 66 ++++++++++++++++++-------------------------
 1 file changed, 28 insertions(+), 38 deletions(-)

diff --git a/drivers/bus/ts-nbus.c b/drivers/bus/ts-nbus.c
index 19c5d1f4e4d7..baf22a82c47a 100644
--- a/drivers/bus/ts-nbus.c
+++ b/drivers/bus/ts-nbus.c
@@ -39,45 +39,39 @@ struct ts_nbus {
 /*
  * request all gpios required by the bus.
  */
-static int ts_nbus_init_pdata(struct platform_device *pdev, struct ts_nbus
-		*ts_nbus)
+static int ts_nbus_init_pdata(struct platform_device *pdev,
+			      struct ts_nbus *ts_nbus)
 {
 	ts_nbus->data = devm_gpiod_get_array(&pdev->dev, "ts,data",
 			GPIOD_OUT_HIGH);
-	if (IS_ERR(ts_nbus->data)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,data-gpio from dts\n");
-		return PTR_ERR(ts_nbus->data);
-	}
+	if (IS_ERR(ts_nbus->data))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->data),
+				     "failed to retrieve ts,data-gpio from dts\n");
 
 	ts_nbus->csn = devm_gpiod_get(&pdev->dev, "ts,csn", GPIOD_OUT_HIGH);
-	if (IS_ERR(ts_nbus->csn)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,csn-gpio from dts\n");
-		return PTR_ERR(ts_nbus->csn);
-	}
+	if (IS_ERR(ts_nbus->csn))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->csn),
+			      "failed to retrieve ts,csn-gpio from dts\n");
 
 	ts_nbus->txrx = devm_gpiod_get(&pdev->dev, "ts,txrx", GPIOD_OUT_HIGH);
-	if (IS_ERR(ts_nbus->txrx)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,txrx-gpio from dts\n");
-		return PTR_ERR(ts_nbus->txrx);
-	}
+	if (IS_ERR(ts_nbus->txrx))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->txrx),
+				     "failed to retrieve ts,txrx-gpio from dts\n");
 
 	ts_nbus->strobe = devm_gpiod_get(&pdev->dev, "ts,strobe", GPIOD_OUT_HIGH);
-	if (IS_ERR(ts_nbus->strobe)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,strobe-gpio from dts\n");
-		return PTR_ERR(ts_nbus->strobe);
-	}
+	if (IS_ERR(ts_nbus->strobe))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->strobe),
+				     "failed to retrieve ts,strobe-gpio from dts\n");
 
 	ts_nbus->ale = devm_gpiod_get(&pdev->dev, "ts,ale", GPIOD_OUT_HIGH);
-	if (IS_ERR(ts_nbus->ale)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,ale-gpio from dts\n");
-		return PTR_ERR(ts_nbus->ale);
-	}
+	if (IS_ERR(ts_nbus->ale))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->ale),
+				     "failed to retrieve ts,ale-gpio from dts\n");
 
 	ts_nbus->rdy = devm_gpiod_get(&pdev->dev, "ts,rdy", GPIOD_IN);
-	if (IS_ERR(ts_nbus->rdy)) {
-		dev_err(&pdev->dev, "failed to retrieve ts,rdy-gpio from dts\n");
-		return PTR_ERR(ts_nbus->rdy);
-	}
+	if (IS_ERR(ts_nbus->rdy))
+		return dev_err_probe(&pdev->dev, PTR_ERR(ts_nbus->rdy),
+				     "failed to retrieve ts,rdy-gpio from dts\n");
 
 	return 0;
 }
@@ -289,25 +283,20 @@ static int ts_nbus_probe(struct platform_device *pdev)
 		return ret;
 
 	pwm = devm_pwm_get(dev, NULL);
-	if (IS_ERR(pwm)) {
-		ret = PTR_ERR(pwm);
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "unable to request PWM\n");
-		return ret;
-	}
+	if (IS_ERR(pwm))
+		return dev_err_probe(dev, PTR_ERR(pwm),
+				     "unable to request PWM\n");
 
 	pwm_init_state(pwm, &state);
-	if (!state.period) {
-		dev_err(&pdev->dev, "invalid PWM period\n");
-		return -EINVAL;
-	}
+	if (!state.period)
+		return dev_err_probe(dev, -EINVAL, "invalid PWM period\n");
 
 	state.duty_cycle = state.period;
 	state.enabled = true;
 
 	ret = pwm_apply_state(pwm, &state);
 	if (ret < 0)
-		return ret;
+		return dev_err_probe(dev, ret, "failed to configure PWM\n");
 
 	/*
 	 * we can now start the FPGA and populate the peripherals.
@@ -321,7 +310,8 @@ static int ts_nbus_probe(struct platform_device *pdev)
 
 	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
 	if (ret < 0)
-		return ret;
+		return dev_err_probe(dev, ret,
+				     "failed to populate platform devices on bus\n");
 
 	dev_info(dev, "initialized\n");
 
-- 
2.42.0