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path: root/drivers/pwm/pwm-lpss.c
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Diffstat (limited to 'drivers/pwm/pwm-lpss.c')
-rw-r--r--drivers/pwm/pwm-lpss.c85
1 files changed, 33 insertions, 52 deletions
diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index 9d965ffe66d1..3444c56b4bed 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -85,7 +85,7 @@ static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm,
unsigned long long on_time_div;
unsigned long c = lpwm->info->clk_rate, base_unit_range;
unsigned long long base_unit, freq = NSEC_PER_SEC;
- u32 orig_ctrl, ctrl;
+ u32 ctrl;
do_div(freq, period_ns);
@@ -93,26 +93,25 @@ static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm,
* The equation is:
* base_unit = round(base_unit_range * freq / c)
*/
- base_unit_range = BIT(lpwm->info->base_unit_bits) - 1;
+ base_unit_range = BIT(lpwm->info->base_unit_bits);
freq *= base_unit_range;
base_unit = DIV_ROUND_CLOSEST_ULL(freq, c);
+ /* base_unit must not be 0 and we also want to avoid overflowing it */
+ base_unit = clamp_val(base_unit, 1, base_unit_range - 1);
on_time_div = 255ULL * duty_ns;
do_div(on_time_div, period_ns);
on_time_div = 255ULL - on_time_div;
- orig_ctrl = ctrl = pwm_lpss_read(pwm);
+ ctrl = pwm_lpss_read(pwm);
ctrl &= ~PWM_ON_TIME_DIV_MASK;
- ctrl &= ~(base_unit_range << PWM_BASE_UNIT_SHIFT);
- base_unit &= base_unit_range;
+ ctrl &= ~((base_unit_range - 1) << PWM_BASE_UNIT_SHIFT);
ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT;
ctrl |= on_time_div;
- if (orig_ctrl != ctrl) {
- pwm_lpss_write(pwm, ctrl);
- pwm_lpss_write(pwm, ctrl | PWM_SW_UPDATE);
- }
+ pwm_lpss_write(pwm, ctrl);
+ pwm_lpss_write(pwm, ctrl | PWM_SW_UPDATE);
}
static inline void pwm_lpss_cond_enable(struct pwm_device *pwm, bool cond)
@@ -121,41 +120,47 @@ static inline void pwm_lpss_cond_enable(struct pwm_device *pwm, bool cond)
pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_ENABLE);
}
+static int pwm_lpss_prepare_enable(struct pwm_lpss_chip *lpwm,
+ struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ int ret;
+
+ ret = pwm_lpss_is_updating(pwm);
+ if (ret)
+ return ret;
+
+ pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
+ pwm_lpss_cond_enable(pwm, lpwm->info->bypass == false);
+ ret = pwm_lpss_wait_for_update(pwm);
+ if (ret)
+ return ret;
+
+ pwm_lpss_cond_enable(pwm, lpwm->info->bypass == true);
+ return 0;
+}
+
static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct pwm_lpss_chip *lpwm = to_lpwm(chip);
- int ret;
+ int ret = 0;
if (state->enabled) {
if (!pwm_is_enabled(pwm)) {
pm_runtime_get_sync(chip->dev);
- ret = pwm_lpss_is_updating(pwm);
- if (ret) {
- pm_runtime_put(chip->dev);
- return ret;
- }
- pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
- pwm_lpss_cond_enable(pwm, lpwm->info->bypass == false);
- ret = pwm_lpss_wait_for_update(pwm);
- if (ret) {
+ ret = pwm_lpss_prepare_enable(lpwm, pwm, state);
+ if (ret)
pm_runtime_put(chip->dev);
- return ret;
- }
- pwm_lpss_cond_enable(pwm, lpwm->info->bypass == true);
} else {
- ret = pwm_lpss_is_updating(pwm);
- if (ret)
- return ret;
- pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
- return pwm_lpss_wait_for_update(pwm);
+ ret = pwm_lpss_prepare_enable(lpwm, pwm, state);
}
} else if (pwm_is_enabled(pwm)) {
pwm_lpss_write(pwm, pwm_lpss_read(pwm) & ~PWM_ENABLE);
pm_runtime_put(chip->dev);
}
- return 0;
+ return ret;
}
static void pwm_lpss_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -255,30 +260,6 @@ int pwm_lpss_remove(struct pwm_lpss_chip *lpwm)
}
EXPORT_SYMBOL_GPL(pwm_lpss_remove);
-int pwm_lpss_suspend(struct device *dev)
-{
- struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev);
- int i;
-
- for (i = 0; i < lpwm->info->npwm; i++)
- lpwm->saved_ctrl[i] = readl(lpwm->regs + i * PWM_SIZE + PWM);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(pwm_lpss_suspend);
-
-int pwm_lpss_resume(struct device *dev)
-{
- struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev);
- int i;
-
- for (i = 0; i < lpwm->info->npwm; i++)
- writel(lpwm->saved_ctrl[i], lpwm->regs + i * PWM_SIZE + PWM);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(pwm_lpss_resume);
-
MODULE_DESCRIPTION("PWM driver for Intel LPSS");
MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
MODULE_LICENSE("GPL v2");