| Message ID | 1353483644-32711-1-git-send-email-avinashphilip@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 21 Nov 2012 13:10:44 +0530, "Philip, Avinash" <avinashphilip@ti.com> wrote: > Add support for encoding PWM properties in bit encoded form with > of_pwm_xlate_with_flags() function support. Platforms require platform > specific PWM properties has to populate in 3rd cell of the pwm-specifier > and PWM driver should also set .of_xlate support with this function. > Currently PWM property polarity encoded in bit position 0 of the third > cell in pwm-specifier. > > Signed-off-by: Philip, Avinash <avinashphilip@ti.com> Looks okay to me. Acked-by: Grant Likely <grant.likely@secretlab.ca> > --- > Changes since v2: > - Move PWM_SPEC_POLARITY to core.c > - Remove dummy function > > Changes since v1: > - of_pwm_xlate_with_flags function support added. > - Documentation update > > :100644 100644 73ec962... 04b0dc4... M Documentation/devicetree/bindings/pwm/pwm.txt > :100644 100644 f5acdaa... 780cb6b... M drivers/pwm/core.c > :100644 100644 112b314... 6d661f3... M include/linux/pwm.h > Documentation/devicetree/bindings/pwm/pwm.txt | 18 +++++++++++++-- > drivers/pwm/core.c | 28 +++++++++++++++++++++++++ > include/linux/pwm.h | 3 ++ > 3 files changed, 46 insertions(+), 3 deletions(-) > > diff --git a/Documentation/devicetree/bindings/pwm/pwm.txt b/Documentation/devicetree/bindings/pwm/pwm.txt > index 73ec962..04b0dc4 100644 > --- a/Documentation/devicetree/bindings/pwm/pwm.txt > +++ b/Documentation/devicetree/bindings/pwm/pwm.txt > @@ -37,10 +37,22 @@ device: > pwm-names = "backlight"; > }; > > +Note that in the example above, specifying the "pwm-names" is redundant > +because the name "backlight" would be used as fallback anyway. > + > pwm-specifier typically encodes the chip-relative PWM number and the PWM > -period in nanoseconds. Note that in the example above, specifying the > -"pwm-names" is redundant because the name "backlight" would be used as > -fallback anyway. > +period in nanoseconds. > + > +Optionally, the pwm-specifier can encode a number of flags in a third cell: > +- bit 0: PWM signal polarity (0: normal polarity, 1: inverse polarity) > + > +Example with optional PWM specifier for inverse polarity > + > + bl: backlight { > + pwms = <&pwm 0 5000000 1>; > + pwm-names = "backlight"; > + }; > + > > 2) PWM controller nodes > ----------------------- > diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c > index f5acdaa..780cb6b 100644 > --- a/drivers/pwm/core.c > +++ b/drivers/pwm/core.c > @@ -32,6 +32,9 @@ > > #define MAX_PWMS 1024 > > +/* flags in the third cell of the DT PWM specifier */ > +#define PWM_SPEC_POLARITY (1 << 0) > + > static DEFINE_MUTEX(pwm_lookup_lock); > static LIST_HEAD(pwm_lookup_list); > static DEFINE_MUTEX(pwm_lock); > @@ -129,6 +132,31 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) > return 0; > } > > +struct pwm_device * > +of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) > +{ > + struct pwm_device *pwm; > + > + if (pc->of_pwm_n_cells < 3) > + return ERR_PTR(-EINVAL); > + > + if (args->args[0] >= pc->npwm) > + return ERR_PTR(-EINVAL); > + > + pwm = pwm_request_from_chip(pc, args->args[0], NULL); > + if (IS_ERR(pwm)) > + return pwm; > + > + pwm_set_period(pwm, args->args[1]); > + > + if (args->args[2] & PWM_SPEC_POLARITY) > + pwm_set_polarity(pwm, PWM_POLARITY_INVERSED); > + else > + pwm_set_polarity(pwm, PWM_POLARITY_NORMAL); > + > + return pwm; > +} > + > static struct pwm_device * > of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) > { > diff --git a/include/linux/pwm.h b/include/linux/pwm.h > index 112b314..6d661f3 100644 > --- a/include/linux/pwm.h > +++ b/include/linux/pwm.h > @@ -171,6 +171,9 @@ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, > unsigned int index, > const char *label); > > +struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc, > + const struct of_phandle_args *args); > + > struct pwm_device *pwm_get(struct device *dev, const char *consumer); > void pwm_put(struct pwm_device *pwm); > > -- > 1.7.0.4 >
On Wed, Nov 21, 2012 at 01:10:44PM +0530, Philip, Avinash wrote: > Add support for encoding PWM properties in bit encoded form with > of_pwm_xlate_with_flags() function support. Platforms require platform > specific PWM properties has to populate in 3rd cell of the pwm-specifier > and PWM driver should also set .of_xlate support with this function. > Currently PWM property polarity encoded in bit position 0 of the third > cell in pwm-specifier. > > Signed-off-by: Philip, Avinash <avinashphilip@ti.com> Applied with two minor stylistic cleanups, thanks. Thierry
diff --git a/Documentation/devicetree/bindings/pwm/pwm.txt b/Documentation/devicetree/bindings/pwm/pwm.txt index 73ec962..04b0dc4 100644 --- a/Documentation/devicetree/bindings/pwm/pwm.txt +++ b/Documentation/devicetree/bindings/pwm/pwm.txt @@ -37,10 +37,22 @@ device: pwm-names = "backlight"; }; +Note that in the example above, specifying the "pwm-names" is redundant +because the name "backlight" would be used as fallback anyway. + pwm-specifier typically encodes the chip-relative PWM number and the PWM -period in nanoseconds. Note that in the example above, specifying the -"pwm-names" is redundant because the name "backlight" would be used as -fallback anyway. +period in nanoseconds. + +Optionally, the pwm-specifier can encode a number of flags in a third cell: +- bit 0: PWM signal polarity (0: normal polarity, 1: inverse polarity) + +Example with optional PWM specifier for inverse polarity + + bl: backlight { + pwms = <&pwm 0 5000000 1>; + pwm-names = "backlight"; + }; + 2) PWM controller nodes ----------------------- diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index f5acdaa..780cb6b 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -32,6 +32,9 @@ #define MAX_PWMS 1024 +/* flags in the third cell of the DT PWM specifier */ +#define PWM_SPEC_POLARITY (1 << 0) + static DEFINE_MUTEX(pwm_lookup_lock); static LIST_HEAD(pwm_lookup_list); static DEFINE_MUTEX(pwm_lock); @@ -129,6 +132,31 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) return 0; } +struct pwm_device * +of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) +{ + struct pwm_device *pwm; + + if (pc->of_pwm_n_cells < 3) + return ERR_PTR(-EINVAL); + + if (args->args[0] >= pc->npwm) + return ERR_PTR(-EINVAL); + + pwm = pwm_request_from_chip(pc, args->args[0], NULL); + if (IS_ERR(pwm)) + return pwm; + + pwm_set_period(pwm, args->args[1]); + + if (args->args[2] & PWM_SPEC_POLARITY) + pwm_set_polarity(pwm, PWM_POLARITY_INVERSED); + else + pwm_set_polarity(pwm, PWM_POLARITY_NORMAL); + + return pwm; +} + static struct pwm_device * of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) { diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 112b314..6d661f3 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -171,6 +171,9 @@ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, unsigned int index, const char *label); +struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc, + const struct of_phandle_args *args); + struct pwm_device *pwm_get(struct device *dev, const char *consumer); void pwm_put(struct pwm_device *pwm);
Add support for encoding PWM properties in bit encoded form with of_pwm_xlate_with_flags() function support. Platforms require platform specific PWM properties has to populate in 3rd cell of the pwm-specifier and PWM driver should also set .of_xlate support with this function. Currently PWM property polarity encoded in bit position 0 of the third cell in pwm-specifier. Signed-off-by: Philip, Avinash <avinashphilip@ti.com> --- Changes since v2: - Move PWM_SPEC_POLARITY to core.c - Remove dummy function Changes since v1: - of_pwm_xlate_with_flags function support added. - Documentation update :100644 100644 73ec962... 04b0dc4... M Documentation/devicetree/bindings/pwm/pwm.txt :100644 100644 f5acdaa... 780cb6b... M drivers/pwm/core.c :100644 100644 112b314... 6d661f3... M include/linux/pwm.h Documentation/devicetree/bindings/pwm/pwm.txt | 18 +++++++++++++-- drivers/pwm/core.c | 28 +++++++++++++++++++++++++ include/linux/pwm.h | 3 ++ 3 files changed, 46 insertions(+), 3 deletions(-)