From: Jernej Skrabec <[email protected]>
H6 PWM core needs deasserted reset line in order to work.
Add an optional probe for it.
Signed-off-by: Jernej Skrabec <[email protected]>
Signed-off-by: Clément Péron <[email protected]>
---
drivers/pwm/pwm-sun4i.c | 32 ++++++++++++++++++++++++++++++--
1 file changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
index 6f5840a1a82d..d194b8ebdb00 100644
--- a/drivers/pwm/pwm-sun4i.c
+++ b/drivers/pwm/pwm-sun4i.c
@@ -16,6 +16,7 @@
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
+#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/time.h>
@@ -78,6 +79,7 @@ struct sun4i_pwm_data {
struct sun4i_pwm_chip {
struct pwm_chip chip;
struct clk *clk;
+ struct reset_control *rst;
void __iomem *base;
spinlock_t ctrl_lock;
const struct sun4i_pwm_data *data;
@@ -365,6 +367,20 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
if (IS_ERR(pwm->clk))
return PTR_ERR(pwm->clk);
+ pwm->rst = devm_reset_control_get_optional(&pdev->dev, NULL);
+ if (IS_ERR(pwm->rst)) {
+ if (PTR_ERR(pwm->rst) == -EPROBE_DEFER)
+ return PTR_ERR(pwm->rst);
+ dev_info(&pdev->dev, "no reset control found\n");
+ }
+
+ /* Deassert reset */
+ ret = reset_control_deassert(pwm->rst);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot deassert reset control\n");
+ return ret;
+ }
+
pwm->chip.dev = &pdev->dev;
pwm->chip.ops = &sun4i_pwm_ops;
pwm->chip.base = -1;
@@ -377,19 +393,31 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
ret = pwmchip_add(&pwm->chip);
if (ret < 0) {
dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
- return ret;
+ goto err_pwm_add;
}
platform_set_drvdata(pdev, pwm);
return 0;
+
+err_pwm_add:
+ reset_control_assert(pwm->rst);
+
+ return ret;
}
static int sun4i_pwm_remove(struct platform_device *pdev)
{
struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = pwmchip_remove(&pwm->chip);
+ if (ret)
+ return ret;
+
+ reset_control_assert(pwm->rst);
- return pwmchip_remove(&pwm->chip);
+ return 0;
}
static struct platform_driver sun4i_pwm_driver = {
--
2.20.1
Hello,
adding Philipp Zabel (= reset controller maintainer) to Cc: and so I'm
not stripping the uncommented parts of the patch.
On Sun, Nov 03, 2019 at 09:33:29PM +0100, Cl?ment P?ron wrote:
> From: Jernej Skrabec <[email protected]>
>
> H6 PWM core needs deasserted reset line in order to work.
>
> Add an optional probe for it.
>
> Signed-off-by: Jernej Skrabec <[email protected]>
> Signed-off-by: Cl?ment P?ron <[email protected]>
> ---
> drivers/pwm/pwm-sun4i.c | 32 ++++++++++++++++++++++++++++++--
> 1 file changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
> index 6f5840a1a82d..d194b8ebdb00 100644
> --- a/drivers/pwm/pwm-sun4i.c
> +++ b/drivers/pwm/pwm-sun4i.c
> @@ -16,6 +16,7 @@
> #include <linux/of_device.h>
> #include <linux/platform_device.h>
> #include <linux/pwm.h>
> +#include <linux/reset.h>
> #include <linux/slab.h>
> #include <linux/spinlock.h>
> #include <linux/time.h>
> @@ -78,6 +79,7 @@ struct sun4i_pwm_data {
> struct sun4i_pwm_chip {
> struct pwm_chip chip;
> struct clk *clk;
> + struct reset_control *rst;
> void __iomem *base;
> spinlock_t ctrl_lock;
> const struct sun4i_pwm_data *data;
> @@ -365,6 +367,20 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
> if (IS_ERR(pwm->clk))
> return PTR_ERR(pwm->clk);
>
> + pwm->rst = devm_reset_control_get_optional(&pdev->dev, NULL);
> + if (IS_ERR(pwm->rst)) {
> + if (PTR_ERR(pwm->rst) == -EPROBE_DEFER)
> + return PTR_ERR(pwm->rst);
> + dev_info(&pdev->dev, "no reset control found\n");
I would degrade this to a dev_dbg. Otherwise this spams the log for all
unaffected machines. devm_reset_control_get_optional() is defined in a
section that has a comment "These inline function calls will be removed
once all consumers have been moved over to the new explicit API.", so I
guess you want devm_reset_control_get_optional_exclusive or even
devm_reset_control_get_optional_shared here.
@Philipp: maybe a check in checkpatch that warns about introduction of
such new instances would be good?!
> + }
> +
> + /* Deassert reset */
> + ret = reset_control_deassert(pwm->rst);
> + if (ret) {
> + dev_err(&pdev->dev, "Cannot deassert reset control\n");
> + return ret;
> + }
> +
> pwm->chip.dev = &pdev->dev;
> pwm->chip.ops = &sun4i_pwm_ops;
> pwm->chip.base = -1;
> @@ -377,19 +393,31 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
> ret = pwmchip_add(&pwm->chip);
> if (ret < 0) {
> dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
> - return ret;
> + goto err_pwm_add;
> }
>
> platform_set_drvdata(pdev, pwm);
>
> return 0;
> +
> +err_pwm_add:
> + reset_control_assert(pwm->rst);
> +
> + return ret;
> }
>
> static int sun4i_pwm_remove(struct platform_device *pdev)
> {
> struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev);
> + int ret;
> +
> + ret = pwmchip_remove(&pwm->chip);
> + if (ret)
> + return ret;
> +
> + reset_control_assert(pwm->rst);
>
> - return pwmchip_remove(&pwm->chip);
> + return 0;
> }
>
> static struct platform_driver sun4i_pwm_driver = {
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-K?nig |
Industrial Linux Solutions | http://www.pengutronix.de/ |
On Mon, 4 Nov 2019 at 09:11, Uwe Kleine-König
<[email protected]> wrote:
>
> Hello,
>
> adding Philipp Zabel (= reset controller maintainer) to Cc: and so I'm
> not stripping the uncommented parts of the patch.
>
> On Sun, Nov 03, 2019 at 09:33:29PM +0100, Clément Péron wrote:
> > From: Jernej Skrabec <[email protected]>
> >
> > H6 PWM core needs deasserted reset line in order to work.
> >
> > Add an optional probe for it.
> >
> > Signed-off-by: Jernej Skrabec <[email protected]>
> > Signed-off-by: Clément Péron <[email protected]>
> > ---
> > drivers/pwm/pwm-sun4i.c | 32 ++++++++++++++++++++++++++++++--
> > 1 file changed, 30 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
> > index 6f5840a1a82d..d194b8ebdb00 100644
> > --- a/drivers/pwm/pwm-sun4i.c
> > +++ b/drivers/pwm/pwm-sun4i.c
> > @@ -16,6 +16,7 @@
> > #include <linux/of_device.h>
> > #include <linux/platform_device.h>
> > #include <linux/pwm.h>
> > +#include <linux/reset.h>
> > #include <linux/slab.h>
> > #include <linux/spinlock.h>
> > #include <linux/time.h>
> > @@ -78,6 +79,7 @@ struct sun4i_pwm_data {
> > struct sun4i_pwm_chip {
> > struct pwm_chip chip;
> > struct clk *clk;
> > + struct reset_control *rst;
> > void __iomem *base;
> > spinlock_t ctrl_lock;
> > const struct sun4i_pwm_data *data;
> > @@ -365,6 +367,20 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
> > if (IS_ERR(pwm->clk))
> > return PTR_ERR(pwm->clk);
> >
> > + pwm->rst = devm_reset_control_get_optional(&pdev->dev, NULL);
> > + if (IS_ERR(pwm->rst)) {
> > + if (PTR_ERR(pwm->rst) == -EPROBE_DEFER)
> > + return PTR_ERR(pwm->rst);
> > + dev_info(&pdev->dev, "no reset control found\n");
>
> I would degrade this to a dev_dbg. Otherwise this spams the log for all
> unaffected machines. devm_reset_control_get_optional() is defined in a
> section that has a comment "These inline function calls will be removed
> once all consumers have been moved over to the new explicit API.", so I
> guess you want devm_reset_control_get_optional_exclusive or even
> devm_reset_control_get_optional_shared here.
Thanks for pointing this, I will change it.
>
> @Philipp: maybe a check in checkpatch that warns about introduction of
> such new instances would be good?!
>
> > + }
> > +
> > + /* Deassert reset */
> > + ret = reset_control_deassert(pwm->rst);
> > + if (ret) {
> > + dev_err(&pdev->dev, "Cannot deassert reset control\n");
> > + return ret;
> > + }
> > +
> > pwm->chip.dev = &pdev->dev;
> > pwm->chip.ops = &sun4i_pwm_ops;
> > pwm->chip.base = -1;
> > @@ -377,19 +393,31 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
> > ret = pwmchip_add(&pwm->chip);
> > if (ret < 0) {
> > dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
> > - return ret;
> > + goto err_pwm_add;
> > }
> >
> > platform_set_drvdata(pdev, pwm);
> >
> > return 0;
> > +
> > +err_pwm_add:
> > + reset_control_assert(pwm->rst);
> > +
> > + return ret;
> > }
> >
> > static int sun4i_pwm_remove(struct platform_device *pdev)
> > {
> > struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev);
> > + int ret;
> > +
> > + ret = pwmchip_remove(&pwm->chip);
> > + if (ret)
> > + return ret;
> > +
> > + reset_control_assert(pwm->rst);
> >
> > - return pwmchip_remove(&pwm->chip);
> > + return 0;
> > }
> >
> > static struct platform_driver sun4i_pwm_driver = {
>
> Best regards
> Uwe
>
> --
> Pengutronix e.K. | Uwe Kleine-König |
> Industrial Linux Solutions | http://www.pengutronix.de/ |
On Mon, Nov 04, 2019 at 09:11:57AM +0100, Uwe Kleine-K?nig wrote:
> Hello,
>
> adding Philipp Zabel (= reset controller maintainer) to Cc: and so I'm
> not stripping the uncommented parts of the patch.
>
> On Sun, Nov 03, 2019 at 09:33:29PM +0100, Cl?ment P?ron wrote:
> > From: Jernej Skrabec <[email protected]>
> >
> > H6 PWM core needs deasserted reset line in order to work.
> >
> > Add an optional probe for it.
> >
> > Signed-off-by: Jernej Skrabec <[email protected]>
> > Signed-off-by: Cl?ment P?ron <[email protected]>
> > ---
> > drivers/pwm/pwm-sun4i.c | 32 ++++++++++++++++++++++++++++++--
> > 1 file changed, 30 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
> > index 6f5840a1a82d..d194b8ebdb00 100644
> > --- a/drivers/pwm/pwm-sun4i.c
> > +++ b/drivers/pwm/pwm-sun4i.c
> > @@ -16,6 +16,7 @@
> > #include <linux/of_device.h>
> > #include <linux/platform_device.h>
> > #include <linux/pwm.h>
> > +#include <linux/reset.h>
> > #include <linux/slab.h>
> > #include <linux/spinlock.h>
> > #include <linux/time.h>
> > @@ -78,6 +79,7 @@ struct sun4i_pwm_data {
> > struct sun4i_pwm_chip {
> > struct pwm_chip chip;
> > struct clk *clk;
> > + struct reset_control *rst;
> > void __iomem *base;
> > spinlock_t ctrl_lock;
> > const struct sun4i_pwm_data *data;
> > @@ -365,6 +367,20 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
> > if (IS_ERR(pwm->clk))
> > return PTR_ERR(pwm->clk);
> >
> > + pwm->rst = devm_reset_control_get_optional(&pdev->dev, NULL);
> > + if (IS_ERR(pwm->rst)) {
> > + if (PTR_ERR(pwm->rst) == -EPROBE_DEFER)
> > + return PTR_ERR(pwm->rst);
> > + dev_info(&pdev->dev, "no reset control found\n");
>
> I would degrade this to a dev_dbg. Otherwise this spams the log for all
> unaffected machines.
The _optional variants return NULL if the reset is not specified in the
device tree, so this is not "no reset control found", but a real error
that should be returned.
> devm_reset_control_get_optional() is defined in a section that has a
> comment "These inline function calls will be removed once all
> consumers have been moved over to the new explicit API.", so I guess
> you want devm_reset_control_get_optional_exclusive or even
> devm_reset_control_get_optional_shared here.
Correct. If this driver deasserts in probe() and asserts the reset in
remove(), this can use the refcounting _shared variant.
> @Philipp: maybe a check in checkpatch that warns about introduction of
> such new instances would be good?!
Yes, that would be helpful.
regards
Philipp
Hi Philipp,
On Tue, 5 Nov 2019 at 08:01, Philipp Zabel <[email protected]> wrote:
>
> On Mon, Nov 04, 2019 at 09:11:57AM +0100, Uwe Kleine-König wrote:
> > Hello,
> >
> > adding Philipp Zabel (= reset controller maintainer) to Cc: and so I'm
> > not stripping the uncommented parts of the patch.
> >
> > On Sun, Nov 03, 2019 at 09:33:29PM +0100, Clément Péron wrote:
> > > From: Jernej Skrabec <[email protected]>
> > >
> > > H6 PWM core needs deasserted reset line in order to work.
> > >
> > > Add an optional probe for it.
> > >
> > > Signed-off-by: Jernej Skrabec <[email protected]>
> > > Signed-off-by: Clément Péron <[email protected]>
> > > ---
> > > drivers/pwm/pwm-sun4i.c | 32 ++++++++++++++++++++++++++++++--
> > > 1 file changed, 30 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
> > > index 6f5840a1a82d..d194b8ebdb00 100644
> > > --- a/drivers/pwm/pwm-sun4i.c
> > > +++ b/drivers/pwm/pwm-sun4i.c
> > > @@ -16,6 +16,7 @@
> > > #include <linux/of_device.h>
> > > #include <linux/platform_device.h>
> > > #include <linux/pwm.h>
> > > +#include <linux/reset.h>
> > > #include <linux/slab.h>
> > > #include <linux/spinlock.h>
> > > #include <linux/time.h>
> > > @@ -78,6 +79,7 @@ struct sun4i_pwm_data {
> > > struct sun4i_pwm_chip {
> > > struct pwm_chip chip;
> > > struct clk *clk;
> > > + struct reset_control *rst;
> > > void __iomem *base;
> > > spinlock_t ctrl_lock;
> > > const struct sun4i_pwm_data *data;
> > > @@ -365,6 +367,20 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
> > > if (IS_ERR(pwm->clk))
> > > return PTR_ERR(pwm->clk);
> > >
> > > + pwm->rst = devm_reset_control_get_optional(&pdev->dev, NULL);
> > > + if (IS_ERR(pwm->rst)) {
> > > + if (PTR_ERR(pwm->rst) == -EPROBE_DEFER)
> > > + return PTR_ERR(pwm->rst);
> > > + dev_info(&pdev->dev, "no reset control found\n");
> >
> > I would degrade this to a dev_dbg. Otherwise this spams the log for all
> > unaffected machines.
>
> The _optional variants return NULL if the reset is not specified in the
> device tree, so this is not "no reset control found", but a real error
> that should be returned.
Correct,
Thanks for the catch,
Clément
>
> > devm_reset_control_get_optional() is defined in a section that has a
> > comment "These inline function calls will be removed once all
> > consumers have been moved over to the new explicit API.", so I guess
> > you want devm_reset_control_get_optional_exclusive or even
> > devm_reset_control_get_optional_shared here.
>
> Correct. If this driver deasserts in probe() and asserts the reset in
> remove(), this can use the refcounting _shared variant.
>
> > @Philipp: maybe a check in checkpatch that warns about introduction of
> > such new instances would be good?!
>
> Yes, that would be helpful.
>
> regards
> Philipp