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path: root/drivers/pwm/pwm-lpc32xx.c
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Diffstat (limited to 'drivers/pwm/pwm-lpc32xx.c')
-rw-r--r--drivers/pwm/pwm-lpc32xx.c23
1 files changed, 21 insertions, 2 deletions
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
index 015a822..1410644 100644
--- a/drivers/pwm/pwm-lpc32xx.c
+++ b/drivers/pwm/pwm-lpc32xx.c
@@ -49,9 +49,24 @@ static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
c = 0; /* 0 set division by 256 */
period_cycles = c;
+ /* The duty-cycle value is as follows:
+ *
+ * DUTY-CYCLE HIGH LEVEL
+ * 1 99.9%
+ * 25 90.0%
+ * 128 50.0%
+ * 220 10.0%
+ * 255 0.1%
+ * 0 0.0%
+ *
+ * In other words, the register value is duty-cycle % 256 with
+ * duty-cycle in the range 1-256.
+ */
c = 256 * duty_ns;
do_div(c, period_ns);
- duty_cycles = c;
+ if (c > 255)
+ c = 255;
+ duty_cycles = 256 - c;
writel(PWM_ENABLE | PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles),
lpc32xx->base + (pwm->hwpwm << 2));
@@ -106,6 +121,7 @@ static int lpc32xx_pwm_probe(struct platform_device *pdev)
lpc32xx->chip.dev = &pdev->dev;
lpc32xx->chip.ops = &lpc32xx_pwm_ops;
lpc32xx->chip.npwm = 2;
+ lpc32xx->chip.base = -1;
ret = pwmchip_add(&lpc32xx->chip);
if (ret < 0) {
@@ -121,8 +137,11 @@ static int lpc32xx_pwm_probe(struct platform_device *pdev)
static int lpc32xx_pwm_remove(struct platform_device *pdev)
{
struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev);
+ unsigned int i;
+
+ for (i = 0; i < lpc32xx->chip.npwm; i++)
+ pwm_disable(&lpc32xx->chip.pwms[i]);
- clk_disable(lpc32xx->clk);
return pwmchip_remove(&lpc32xx->chip);
}