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authorTony Prisk <linux@prisktech.co.nz>2013-01-03 08:44:16 +1300
committerThierry Reding <thierry.reding@avionic-design.de>2013-01-09 08:17:12 +0100
commit3ccb1c1702ed4bb07006d20c8173899a69dae242 (patch)
treeef55173274b60bec942b0dcfc15f1df3614029fe /drivers/pwm
parent8ab432caa46413c9f3ca81d82ea9fa5bae07c3c1 (diff)
downloadvexpress-lsk-3ccb1c1702ed4bb07006d20c8173899a69dae242.tar.gz
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>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-vt8500.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c
index bbc37504103..98d79e9f014 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,
};
@@ -197,6 +218,8 @@ static int vt8500_pwm_probe(struct platform_device *pdev)
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;