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path: root/drivers/pwm/pwm-iqs620a.c
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Diffstat (limited to 'drivers/pwm/pwm-iqs620a.c')
-rw-r--r--drivers/pwm/pwm-iqs620a.c94
1 files changed, 41 insertions, 53 deletions
diff --git a/drivers/pwm/pwm-iqs620a.c b/drivers/pwm/pwm-iqs620a.c
index 5ede8255926e..957b972c458b 100644
--- a/drivers/pwm/pwm-iqs620a.c
+++ b/drivers/pwm/pwm-iqs620a.c
@@ -37,16 +37,34 @@ struct iqs620_pwm_private {
struct pwm_chip chip;
struct notifier_block notifier;
struct mutex lock;
- bool out_en;
- u8 duty_val;
+ unsigned int duty_scale;
};
+static int iqs620_pwm_init(struct iqs620_pwm_private *iqs620_pwm,
+ unsigned int duty_scale)
+{
+ struct iqs62x_core *iqs62x = iqs620_pwm->iqs62x;
+ int ret;
+
+ if (!duty_scale)
+ return regmap_update_bits(iqs62x->regmap, IQS620_PWR_SETTINGS,
+ IQS620_PWR_SETTINGS_PWM_OUT, 0);
+
+ ret = regmap_write(iqs62x->regmap, IQS620_PWM_DUTY_CYCLE,
+ duty_scale - 1);
+ if (ret)
+ return ret;
+
+ return regmap_update_bits(iqs62x->regmap, IQS620_PWR_SETTINGS,
+ IQS620_PWR_SETTINGS_PWM_OUT, 0xff);
+}
+
static int iqs620_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct iqs620_pwm_private *iqs620_pwm;
- struct iqs62x_core *iqs62x;
- u64 duty_scale;
+ unsigned int duty_cycle;
+ unsigned int duty_scale;
int ret;
if (state->polarity != PWM_POLARITY_NORMAL)
@@ -56,7 +74,6 @@ static int iqs620_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
return -EINVAL;
iqs620_pwm = container_of(chip, struct iqs620_pwm_private, chip);
- iqs62x = iqs620_pwm->iqs62x;
/*
* The duty cycle generated by the device is calculated as follows:
@@ -70,38 +87,18 @@ static int iqs620_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
* For lower duty cycles (e.g. 0), the PWM output is simply disabled to
* allow an external pull-down resistor to hold the GPIO3/LTX pin low.
*/
- duty_scale = div_u64(state->duty_cycle * 256, IQS620_PWM_PERIOD_NS);
-
- mutex_lock(&iqs620_pwm->lock);
-
- if (!state->enabled || !duty_scale) {
- ret = regmap_update_bits(iqs62x->regmap, IQS620_PWR_SETTINGS,
- IQS620_PWR_SETTINGS_PWM_OUT, 0);
- if (ret)
- goto err_mutex;
- }
+ duty_cycle = min_t(u64, state->duty_cycle, IQS620_PWM_PERIOD_NS);
+ duty_scale = duty_cycle * 256 / IQS620_PWM_PERIOD_NS;
- if (duty_scale) {
- u8 duty_val = min_t(u64, duty_scale - 1, 0xff);
+ if (!state->enabled)
+ duty_scale = 0;
- ret = regmap_write(iqs62x->regmap, IQS620_PWM_DUTY_CYCLE,
- duty_val);
- if (ret)
- goto err_mutex;
-
- iqs620_pwm->duty_val = duty_val;
- }
-
- if (state->enabled && duty_scale) {
- ret = regmap_update_bits(iqs62x->regmap, IQS620_PWR_SETTINGS,
- IQS620_PWR_SETTINGS_PWM_OUT, 0xff);
- if (ret)
- goto err_mutex;
- }
+ mutex_lock(&iqs620_pwm->lock);
- iqs620_pwm->out_en = state->enabled;
+ ret = iqs620_pwm_init(iqs620_pwm, duty_scale);
+ if (!ret)
+ iqs620_pwm->duty_scale = duty_scale;
-err_mutex:
mutex_unlock(&iqs620_pwm->lock);
return ret;
@@ -119,12 +116,11 @@ static void iqs620_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
/*
* Since the device cannot generate a 0% duty cycle, requests to do so
* cause subsequent calls to iqs620_pwm_get_state to report the output
- * as disabled with duty cycle equal to that which was in use prior to
- * the request. This is not ideal, but is the best compromise based on
+ * as disabled. This is not ideal, but is the best compromise based on
* the capabilities of the device.
*/
- state->enabled = iqs620_pwm->out_en;
- state->duty_cycle = DIV_ROUND_UP((iqs620_pwm->duty_val + 1) *
+ state->enabled = iqs620_pwm->duty_scale > 0;
+ state->duty_cycle = DIV_ROUND_UP(iqs620_pwm->duty_scale *
IQS620_PWM_PERIOD_NS, 256);
mutex_unlock(&iqs620_pwm->lock);
@@ -136,7 +132,6 @@ static int iqs620_pwm_notifier(struct notifier_block *notifier,
unsigned long event_flags, void *context)
{
struct iqs620_pwm_private *iqs620_pwm;
- struct iqs62x_core *iqs62x;
int ret;
if (!(event_flags & BIT(IQS62X_EVENT_SYS_RESET)))
@@ -144,7 +139,6 @@ static int iqs620_pwm_notifier(struct notifier_block *notifier,
iqs620_pwm = container_of(notifier, struct iqs620_pwm_private,
notifier);
- iqs62x = iqs620_pwm->iqs62x;
mutex_lock(&iqs620_pwm->lock);
@@ -153,16 +147,8 @@ static int iqs620_pwm_notifier(struct notifier_block *notifier,
* of a device reset, so nothing else is printed here unless there is
* an additional failure.
*/
- ret = regmap_write(iqs62x->regmap, IQS620_PWM_DUTY_CYCLE,
- iqs620_pwm->duty_val);
- if (ret)
- goto err_mutex;
+ ret = iqs620_pwm_init(iqs620_pwm, iqs620_pwm->duty_scale);
- ret = regmap_update_bits(iqs62x->regmap, IQS620_PWR_SETTINGS,
- IQS620_PWR_SETTINGS_PWM_OUT,
- iqs620_pwm->out_en ? 0xff : 0);
-
-err_mutex:
mutex_unlock(&iqs620_pwm->lock);
if (ret) {
@@ -209,12 +195,14 @@ static int iqs620_pwm_probe(struct platform_device *pdev)
ret = regmap_read(iqs62x->regmap, IQS620_PWR_SETTINGS, &val);
if (ret)
return ret;
- iqs620_pwm->out_en = val & IQS620_PWR_SETTINGS_PWM_OUT;
- ret = regmap_read(iqs62x->regmap, IQS620_PWM_DUTY_CYCLE, &val);
- if (ret)
- return ret;
- iqs620_pwm->duty_val = val;
+ if (val & IQS620_PWR_SETTINGS_PWM_OUT) {
+ ret = regmap_read(iqs62x->regmap, IQS620_PWM_DUTY_CYCLE, &val);
+ if (ret)
+ return ret;
+
+ iqs620_pwm->duty_scale = val + 1;
+ }
iqs620_pwm->chip.dev = &pdev->dev;
iqs620_pwm->chip.ops = &iqs620_pwm_ops;