Cc += reset framework maintainer Hello Jernej,
On Fri, Jul 26, 2019 at 08:40:41PM +0200, Jernej Skrabec wrote: > H6 PWM core needs deasserted reset line in order to work. > > Add a quirk for it. > > Signed-off-by: Jernej Skrabec <[email protected]> > --- > drivers/pwm/pwm-sun4i.c | 27 +++++++++++++++++++++++++-- > 1 file changed, 25 insertions(+), 2 deletions(-) > > diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c > index de78c824bbfd..1b7be8fbde86 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> > @@ -72,12 +73,14 @@ static const u32 prescaler_table[] = { > > struct sun4i_pwm_data { > bool has_prescaler_bypass; > + bool has_reset; > unsigned int npwm; > }; > > 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; > @@ -371,6 +374,14 @@ static int sun4i_pwm_probe(struct platform_device *pdev) > if (IS_ERR(pwm->clk)) > return PTR_ERR(pwm->clk); > > + if (pwm->data->has_reset) { > + pwm->rst = devm_reset_control_get(&pdev->dev, NULL); > + if (IS_ERR(pwm->rst)) > + return PTR_ERR(pwm->rst); > + > + reset_control_deassert(pwm->rst); > + } > + I wonder why there is a need to track if a given chip needs a reset line. I'd just use devm_reset_control_get_optional() and drop the .has_reset member in struct sun4i_pwm_data. > pwm->chip.dev = &pdev->dev; > pwm->chip.ops = &sun4i_pwm_ops; > pwm->chip.base = -1; > @@ -383,19 +394,31 @@ 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; > > - return pwmchip_remove(&pwm->chip); > + reset_control_assert(pwm->rst); > + > + return 0; > } > > static struct platform_driver sun4i_pwm_driver = { -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |
