6.17-stable review patch. If anyone has any objections, please let me know.
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From: Uwe Kleine-König u.kleine-koenig@baylibre.com
[ Upstream commit de5855613263b426ee697dd30224322f2e634dec ]
The output of a PWM channel is configured by four register values. Write them in a single i2c transaction to ensure glitch free updates.
Signed-off-by: Uwe Kleine-König u.kleine-koenig@baylibre.com Link: https://lore.kernel.org/r/bfa8c0267c9ec059d0d77f146998d564654c75ca.175378409... Signed-off-by: Uwe Kleine-König ukleinek@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pwm/pwm-pca9685.c | 46 ++++++++++++++++++++++++--------------- 1 file changed, 29 insertions(+), 17 deletions(-)
diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c index 9ce75704a15f8..91f96b28ce1b5 100644 --- a/drivers/pwm/pwm-pca9685.c +++ b/drivers/pwm/pwm-pca9685.c @@ -61,6 +61,8 @@ #define MODE1_SUB2 BIT(2) #define MODE1_SUB1 BIT(3) #define MODE1_SLEEP BIT(4) +#define MODE1_AI BIT(5) + #define MODE2_INVRT BIT(4) #define MODE2_OUTDRV BIT(2)
@@ -131,6 +133,19 @@ static int pca9685_write_reg(struct pwm_chip *chip, unsigned int reg, unsigned i return err; }
+static int pca9685_write_4reg(struct pwm_chip *chip, unsigned int reg, u8 val[4]) +{ + struct pca9685 *pca = to_pca(chip); + struct device *dev = pwmchip_parent(chip); + int err; + + err = regmap_bulk_write(pca->regmap, reg, val, 4); + if (err) + dev_err(dev, "regmap_write to register 0x%x failed: %pe\n", reg, ERR_PTR(err)); + + return err; +} + /* Helper function to set the duty cycle ratio to duty/4096 (e.g. duty=2048 -> 50%) */ static void pca9685_pwm_set_duty(struct pwm_chip *chip, int channel, unsigned int duty) { @@ -143,12 +158,10 @@ static void pca9685_pwm_set_duty(struct pwm_chip *chip, int channel, unsigned in return; } else if (duty >= PCA9685_COUNTER_RANGE) { /* Set the full ON bit and clear the full OFF bit */ - pca9685_write_reg(chip, REG_ON_H(channel), LED_FULL); - pca9685_write_reg(chip, REG_OFF_H(channel), 0); + pca9685_write_4reg(chip, REG_ON_L(channel), (u8[4]){ 0, LED_FULL, 0, 0 }); return; }
- if (pwm->state.usage_power && channel < PCA9685_MAXCHAN) { /* * If usage_power is set, the pca9685 driver will phase shift @@ -163,12 +176,9 @@ static void pca9685_pwm_set_duty(struct pwm_chip *chip, int channel, unsigned in
off = (on + duty) % PCA9685_COUNTER_RANGE;
- /* Set ON time (clears full ON bit) */ - pca9685_write_reg(chip, REG_ON_L(channel), on & 0xff); - pca9685_write_reg(chip, REG_ON_H(channel), (on >> 8) & 0xf); - /* Set OFF time (clears full OFF bit) */ - pca9685_write_reg(chip, REG_OFF_L(channel), off & 0xff); - pca9685_write_reg(chip, REG_OFF_H(channel), (off >> 8) & 0xf); + /* implicitly clear full ON and full OFF bit */ + pca9685_write_4reg(chip, REG_ON_L(channel), + (u8[4]){ on & 0xff, (on >> 8) & 0xf, off & 0xff, (off >> 8) & 0xf }); }
static unsigned int pca9685_pwm_get_duty(struct pwm_chip *chip, int channel) @@ -544,9 +554,8 @@ static int pca9685_pwm_probe(struct i2c_client *client)
mutex_init(&pca->lock);
- ret = pca9685_read_reg(chip, PCA9685_MODE2, ®); - if (ret) - return ret; + /* clear MODE2_OCH */ + reg = 0;
if (device_property_read_bool(&client->dev, "invert")) reg |= MODE2_INVRT; @@ -562,16 +571,19 @@ static int pca9685_pwm_probe(struct i2c_client *client) if (ret) return ret;
- /* Disable all LED ALLCALL and SUBx addresses to avoid bus collisions */ + /* + * Disable all LED ALLCALL and SUBx addresses to avoid bus collisions, + * enable Auto-Increment. + */ pca9685_read_reg(chip, PCA9685_MODE1, ®); reg &= ~(MODE1_ALLCALL | MODE1_SUB1 | MODE1_SUB2 | MODE1_SUB3); + reg |= MODE1_AI; pca9685_write_reg(chip, PCA9685_MODE1, reg);
/* Reset OFF/ON registers to POR default */ - pca9685_write_reg(chip, PCA9685_ALL_LED_OFF_L, 0); - pca9685_write_reg(chip, PCA9685_ALL_LED_OFF_H, LED_FULL); - pca9685_write_reg(chip, PCA9685_ALL_LED_ON_L, 0); - pca9685_write_reg(chip, PCA9685_ALL_LED_ON_H, LED_FULL); + ret = pca9685_write_4reg(chip, PCA9685_ALL_LED_ON_L, (u8[]){ 0, LED_FULL, 0, LED_FULL }); + if (ret < 0) + return dev_err_probe(&client->dev, ret, "Failed to reset ON/OFF registers\n");
chip->ops = &pca9685_pwm_ops;