pwm: vt8500: Add polarity support
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>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c
index bbc3750..98d79e9 100644
--- a/drivers/pwm/pwm-vt8500.c
+++ b/drivers/pwm/pwm-vt8500.c
@@ -164,10 +164,31 @@
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,
};
@@ -197,6 +218,8 @@
chip->chip.dev = &pdev->dev;
chip->chip.ops = &vt8500_pwm_ops;
+ chip->chip.of_xlate = of_pwm_xlate_with_flags;
+ chip->chip.of_pwm_n_cells = 3;
chip->chip.base = -1;
chip->chip.npwm = VT8500_NR_PWMS;