| Message ID | 1356899005-8876-2-git-send-email-linux@prisktech.co.nz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Dec 31, 2012 at 09:23:25AM +1300, Tony Prisk wrote: > Add support to set polarity on pwm devices, allowing for inverted > duty cycles. "PWM devices", please. Maybe the subject could be something less API specific, like "pwm: vt8500: Add polarity support". > .../devicetree/bindings/pwm/vt8500-pwm.txt | 7 ++++--- > drivers/pwm/pwm-vt8500.c | 21 ++++++++++++++++++++ > 2 files changed, 25 insertions(+), 3 deletions(-) > > diff --git a/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt b/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt > index bcc6367..f71cc8d 100644 > --- a/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt > +++ b/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt > @@ -3,14 +3,15 @@ VIA/Wondermedia VT8500/WM8xxx series SoC PWM controller > Required properties: > - compatible: should be "via,vt8500-pwm" > - reg: physical base address and length of the controller's registers > -- #pwm-cells: should be 2. The first cell specifies the per-chip index > - of the PWM to use and the second cell is the period in nanoseconds. > +- #pwm-cells: should be 3. The first cell specifies the per-chip index > + of the PWM to use, the second cell is the period in nanoseconds, and the > + third cell is for flags. This needs to document what flags the third cell encodes and how. Either that or refer to the generic PWM binding documentation. > diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c > index 27ed0f4..9abf561 100644 > --- a/drivers/pwm/pwm-vt8500.c > +++ b/drivers/pwm/pwm-vt8500.c > @@ -164,10 +164,31 @@ static void vt8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > clk_disable(vt8500->clk); > } > > +static int vt8500_pwm_set_polarity(struct pwm_chip *chip, > + struct pwm_device *pwm, > + enum pwm_polarity polarity) > +{ > + struct vt8500_chip *vt8500 = to_vt8500_chip(chip); > + u32 val; > + > + val = readl(vt8500->base + REG_CTRL(pwm->hwpwm)); > + > + if (polarity == PWM_POLARITY_INVERSED) > + val |= CTRL_INVERT; > + else > + val &= ~CTRL_INVERT; > + > + writel(val, vt8500->base + REG_CTRL(pwm->hwpwm)); > + pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE); > + > + return 0; > +} > + > static struct pwm_ops vt8500_pwm_ops = { > .enable = vt8500_pwm_enable, > .disable = vt8500_pwm_disable, > .config = vt8500_pwm_config, > + .set_polarity = vt8500_pwm_set_polarity, > .owner = THIS_MODULE, > }; This patch is missing the corresponding changes to the DT code. You need to override the pwm_chip's .of_xlate() and .of_pwm_n_cells fields. You can look at the TI EHRPWM driver if you need inspiration. Thierry
diff --git a/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt b/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt index bcc6367..f71cc8d 100644 --- a/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt +++ b/Documentation/devicetree/bindings/pwm/vt8500-pwm.txt @@ -3,14 +3,15 @@ VIA/Wondermedia VT8500/WM8xxx series SoC PWM controller Required properties: - compatible: should be "via,vt8500-pwm" - reg: physical base address and length of the controller's registers -- #pwm-cells: should be 2. The first cell specifies the per-chip index - of the PWM to use and the second cell is the period in nanoseconds. +- #pwm-cells: should be 3. The first cell specifies the per-chip index + of the PWM to use, the second cell is the period in nanoseconds, and the + third cell is for flags. - clocks: phandle to the PWM source clock Example: pwm1: pwm@d8220000 { - #pwm-cells = <2>; + #pwm-cells = <3>; compatible = "via,vt8500-pwm"; reg = <0xd8220000 0x1000>; clocks = <&clkpwm>; diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c index 27ed0f4..9abf561 100644 --- a/drivers/pwm/pwm-vt8500.c +++ b/drivers/pwm/pwm-vt8500.c @@ -164,10 +164,31 @@ static void vt8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) clk_disable(vt8500->clk); } +static int vt8500_pwm_set_polarity(struct pwm_chip *chip, + struct pwm_device *pwm, + enum pwm_polarity polarity) +{ + struct vt8500_chip *vt8500 = to_vt8500_chip(chip); + u32 val; + + val = readl(vt8500->base + REG_CTRL(pwm->hwpwm)); + + if (polarity == PWM_POLARITY_INVERSED) + val |= CTRL_INVERT; + else + val &= ~CTRL_INVERT; + + writel(val, vt8500->base + REG_CTRL(pwm->hwpwm)); + pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE); + + return 0; +} + static struct pwm_ops vt8500_pwm_ops = { .enable = vt8500_pwm_enable, .disable = vt8500_pwm_disable, .config = vt8500_pwm_config, + .set_polarity = vt8500_pwm_set_polarity, .owner = THIS_MODULE, };
Add support to set polarity on pwm devices, allowing for inverted duty cycles. Also update the binding document to #pwm-cells = <3> to allow passing the flags from devicetree. Signed-off-by: Tony Prisk <linux@prisktech.co.nz> --- .../devicetree/bindings/pwm/vt8500-pwm.txt | 7 ++++--- drivers/pwm/pwm-vt8500.c | 21 ++++++++++++++++++++ 2 files changed, 25 insertions(+), 3 deletions(-)