[PATCH 2/4] pwm: pca9685: remove ALL_LED PWM channel

Matthias Schiffer
2020-02-26T13:53:08Z

The interaction of the ALL_LED PWM channel with the other channels was
not well-defined. As the ALL_LED feature does not seem very useful and
it was making the code significantly more complex, simply remove it.

Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
---
drivers/pwm/pwm-pca9685.c | 115 ++++++--------------------------------
1 file changed, 17 insertions(+), 98 deletions(-)

diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c
index 19ac97108a64..393ab92aa945 100644
--- a/drivers/pwm/pwm-pca9685.c
+++ b/drivers/pwm/pwm-pca9685.c
@@ -105,27 +105,12 @@ static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)

static bool pca9685_pwm_is_gpio(struct pca9685 *pca, struct pwm_device *pwm)
{
- bool is_gpio = false;
+ bool is_gpio;

mutex_lock(&pca->lock);
-
- if (pwm->hwpwm >= PCA9685_MAXCHAN) {
- unsigned int i;
-
- /*
- * Check if any of the GPIOs are requested and in that case
- * prevent using the "all LEDs" channel.
- */
- for (i = 0; i < pca->gpio.ngpio; i++)
- if (gpiochip_is_requested(&pca->gpio, i)) {
- is_gpio = true;
- break;
- }
- } else if (pwm_get_chip_data(pwm)) {
- is_gpio = true;
- }
-
+ is_gpio = !!pwm_get_chip_data(pwm);
mutex_unlock(&pca->lock);
+
return is_gpio;
}

@@ -239,7 +224,6 @@ static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
{
struct pca9685 *pca = to_pca(chip);
unsigned long long duty;
- unsigned int reg;
int prescale;

if (period_ns != pca->period_ns) {
@@ -272,39 +256,18 @@ static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
}

if (duty_ns < 1) {
- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_OFF_H;
- else
- reg = LED_N_OFF_H(pwm->hwpwm);
-
- regmap_write(pca->regmap, reg, LED_FULL);
+ regmap_write(pca->regmap, LED_N_OFF_H(pwm->hwpwm), LED_FULL);

return 0;
}

if (duty_ns == period_ns) {
/* Clear both OFF registers */
- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_OFF_L;
- else
- reg = LED_N_OFF_L(pwm->hwpwm);
-
- regmap_write(pca->regmap, reg, 0x0);
-
- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_OFF_H;
- else
- reg = LED_N_OFF_H(pwm->hwpwm);
-
- regmap_write(pca->regmap, reg, 0x0);
+ regmap_write(pca->regmap, LED_N_OFF_L(pwm->hwpwm), 0x0);
+ regmap_write(pca->regmap, LED_N_OFF_H(pwm->hwpwm), 0x0);

/* Set the full ON bit */
- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_ON_H;
- else
- reg = LED_N_ON_H(pwm->hwpwm);
-
- regmap_write(pca->regmap, reg, LED_FULL);
+ regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), LED_FULL);

return 0;
}
@@ -312,27 +275,12 @@ static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
duty = PCA9685_COUNTER_RANGE * (unsigned long long)duty_ns;
duty = DIV_ROUND_UP_ULL(duty, period_ns);

- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_OFF_L;
- else
- reg = LED_N_OFF_L(pwm->hwpwm);
-
- regmap_write(pca->regmap, reg, (int)duty & 0xff);
-
- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_OFF_H;
- else
- reg = LED_N_OFF_H(pwm->hwpwm);
-
- regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf);
+ regmap_write(pca->regmap, LED_N_OFF_L(pwm->hwpwm), (int)duty & 0xff);
+ regmap_write(pca->regmap, LED_N_OFF_H(pwm->hwpwm),
+ ((int)duty >> 8) & 0xf);

/* Clear the full ON bit, otherwise the set OFF time has no effect */
- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_ON_H;
- else
- reg = LED_N_ON_H(pwm->hwpwm);
-
- regmap_write(pca->regmap, reg, 0);
+ regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), 0);

return 0;
}
@@ -340,36 +288,19 @@ static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct pca9685 *pca = to_pca(chip);
- unsigned int reg;

/*
* The PWM subsystem does not support a pre-delay.
* So, set the ON-timeout to 0
*/
- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_ON_L;
- else
- reg = LED_N_ON_L(pwm->hwpwm);
-
- regmap_write(pca->regmap, reg, 0);
-
- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_ON_H;
- else
- reg = LED_N_ON_H(pwm->hwpwm);
-
- regmap_write(pca->regmap, reg, 0);
+ regmap_write(pca->regmap, LED_N_ON_L(pwm->hwpwm), 0);
+ regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), 0);

/*
* Clear the full-off bit.
* It has precedence over the others and must be off.
*/
- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_OFF_H;
- else
- reg = LED_N_OFF_H(pwm->hwpwm);
-
- regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0);
+ regmap_update_bits(pca->regmap, LED_N_OFF_H(pwm->hwpwm), LED_FULL, 0x0);

return 0;
}
@@ -377,22 +308,11 @@ static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct pca9685 *pca = to_pca(chip);
- unsigned int reg;
-
- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_OFF_H;
- else
- reg = LED_N_OFF_H(pwm->hwpwm);

- regmap_write(pca->regmap, reg, LED_FULL);
+ regmap_write(pca->regmap, LED_N_OFF_H(pwm->hwpwm), LED_FULL);

/* Clear the LED_OFF counter. */
- if (pwm->hwpwm >= PCA9685_MAXCHAN)
- reg = PCA9685_ALL_LED_OFF_L;
- else
- reg = LED_N_OFF_L(pwm->hwpwm);
-
- regmap_write(pca->regmap, reg, 0x0);
+ regmap_write(pca->regmap, LED_N_OFF_L(pwm->hwpwm), 0x0);
}

static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
@@ -469,8 +389,7 @@ static int pca9685_pwm_probe(struct i2c_client *client,
regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0);

pca->chip.ops = &pca9685_pwm_ops;
- /* add an extra channel for ALL_LED */
- pca->chip.npwm = PCA9685_MAXCHAN + 1;
+ pca->chip.npwm = PCA9685_MAXCHAN;

pca->chip.dev = &client->dev;
pca->chip.base = -1;
--
2.17.1