diff options
| -rw-r--r-- | drivers/pwm/pwm-pca9685.c | 261 |
1 files changed, 91 insertions, 170 deletions
diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c index 00976b2c57b2..b740b824bda9 100644 --- a/drivers/pwm/pwm-pca9685.c +++ b/drivers/pwm/pwm-pca9685.c @@ -51,7 +51,6 @@ #define PCA9685_PRESCALE_MAX 0xFF /* => min. frequency of 24 Hz */ #define PCA9685_COUNTER_RANGE 4096 -#define PCA9685_DEFAULT_PERIOD 5000000 /* Default period_ns = 1/200 Hz */ #define PCA9685_OSC_CLOCK_MHZ 25 /* Internal oscillator with 25 MHz */ #define PCA9685_NUMREGS 0xFF @@ -71,10 +70,14 @@ #define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N))) #define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N))) +#define REG_ON_H(C) ((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_ON_H : LED_N_ON_H((C))) +#define REG_ON_L(C) ((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_ON_L : LED_N_ON_L((C))) +#define REG_OFF_H(C) ((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_OFF_H : LED_N_OFF_H((C))) +#define REG_OFF_L(C) ((C) >= PCA9685_MAXCHAN ? PCA9685_ALL_LED_OFF_L : LED_N_OFF_L((C))) + struct pca9685 { struct pwm_chip chip; struct regmap *regmap; - int period_ns; #if IS_ENABLED(CONFIG_GPIOLIB) struct mutex lock; struct gpio_chip gpio; @@ -87,6 +90,53 @@ static inline struct pca9685 *to_pca(struct pwm_chip *chip) return container_of(chip, struct pca9685, chip); } +/* Helper function to set the duty cycle ratio to duty/4096 (e.g. duty=2048 -> 50%) */ +static void pca9685_pwm_set_duty(struct pca9685 *pca, int channel, unsigned int duty) +{ + if (duty == 0) { + /* Set the full OFF bit, which has the highest precedence */ + regmap_write(pca->regmap, REG_OFF_H(channel), LED_FULL); + } else if (duty >= PCA9685_COUNTER_RANGE) { + /* Set the full ON bit and clear the full OFF bit */ + regmap_write(pca->regmap, REG_ON_H(channel), LED_FULL); + regmap_write(pca->regmap, REG_OFF_H(channel), 0); + } else { + /* Set OFF time (clears the full OFF bit) */ + regmap_write(pca->regmap, REG_OFF_L(channel), duty & 0xff); + regmap_write(pca->regmap, REG_OFF_H(channel), (duty >> 8) & 0xf); + /* Clear the full ON bit */ + regmap_write(pca->regmap, REG_ON_H(channel), 0); + } +} + +static unsigned int pca9685_pwm_get_duty(struct pca9685 *pca, int channel) +{ + unsigned int off_h = 0, val = 0; + + if (WARN_ON(channel >= PCA9685_MAXCHAN)) { + /* HW does not support reading state of "all LEDs" channel */ + return 0; + } + + regmap_read(pca->regmap, LED_N_OFF_H(channel), &off_h); + if (off_h & LED_FULL) { + /* Full OFF bit is set */ + return 0; + } + + regmap_read(pca->regmap, LED_N_ON_H(channel), &val); + if (val & LED_FULL) { + /* Full ON bit is set */ + return PCA9685_COUNTER_RANGE; + } + + if (regmap_read(pca->regmap, LED_N_OFF_L(channel), &val)) { + /* Reset val to 0 in case reading LED_N_OFF_L failed */ + val = 0; + } + return ((off_h & 0xf) << 8) | (val & 0xff); +} + #if IS_ENABLED(CONFIG_GPIOLIB) static bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca, int pwm_idx) { @@ -138,34 +188,23 @@ static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset) static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset) { struct pca9685 *pca = gpiochip_get_data(gpio); - struct pwm_device *pwm = &pca->chip.pwms[offset]; - unsigned int value; - regmap_read(pca->regmap, LED_N_ON_H(pwm->hwpwm), &value); - - return value & LED_FULL; + return pca9685_pwm_get_duty(pca, offset) != 0; } static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset, int value) { struct pca9685 *pca = gpiochip_get_data(gpio); - struct pwm_device *pwm = &pca->chip.pwms[offset]; - unsigned int on = value ? LED_FULL : 0; - - /* Clear both OFF registers */ - regmap_write(pca->regmap, LED_N_OFF_L(pwm->hwpwm), 0); - regmap_write(pca->regmap, LED_N_OFF_H(pwm->hwpwm), 0); - /* Set the full ON bit */ - regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), on); + pca9685_pwm_set_duty(pca, offset, value ? PCA9685_COUNTER_RANGE : 0); } static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset) { struct pca9685 *pca = gpiochip_get_data(gpio); - pca9685_pwm_gpio_set(gpio, offset, 0); + pca9685_pwm_set_duty(pca, offset, 0); pm_runtime_put(pca->chip.dev); pca9685_pwm_clear_inuse(pca, offset); } @@ -246,167 +285,52 @@ static void pca9685_set_sleep_mode(struct pca9685 *pca, bool enable) } } -static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, - int duty_ns, int period_ns) +static int pca9685_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) { struct pca9685 *pca = to_pca(chip); - unsigned long long duty; - unsigned int reg; - int prescale; - - if (period_ns != pca->period_ns) { - prescale = DIV_ROUND_CLOSEST(PCA9685_OSC_CLOCK_MHZ * period_ns, - PCA9685_COUNTER_RANGE * 1000) - 1; - - if (prescale >= PCA9685_PRESCALE_MIN && - prescale <= PCA9685_PRESCALE_MAX) { - /* - * Putting the chip briefly into SLEEP mode - * at this point won't interfere with the - * pm_runtime framework, because the pm_runtime - * state is guaranteed active here. - */ - /* Put chip into sleep mode */ - pca9685_set_sleep_mode(pca, true); - - /* Change the chip-wide output frequency */ - regmap_write(pca->regmap, PCA9685_PRESCALE, prescale); - - /* Wake the chip up */ - pca9685_set_sleep_mode(pca, false); - - pca->period_ns = period_ns; - } else { - dev_err(chip->dev, - "prescaler not set: period out of bounds!\n"); - return -EINVAL; - } - } + unsigned long long duty, prescale; + unsigned int val = 0; - if (duty_ns < 1) { - if (pwm->hwpwm >= PCA9685_MAXCHAN) - reg = PCA9685_ALL_LED_OFF_H; - else - reg = LED_N_OFF_H(pwm->hwpwm); + if (state->polarity != PWM_POLARITY_NORMAL) + return -EINVAL; - regmap_write(pca->regmap, reg, LED_FULL); - - return 0; + prescale = DIV_ROUND_CLOSEST_ULL(PCA9685_OSC_CLOCK_MHZ * state->period, + PCA9685_COUNTER_RANGE * 1000) - 1; + if (prescale < PCA9685_PRESCALE_MIN || prescale > PCA9685_PRESCALE_MAX) { + dev_err(chip->dev, "pwm not changed: period out of bounds!\n"); + return -EINVAL; } - 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); - - /* 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); - + if (!state->enabled) { + pca9685_pwm_set_duty(pca, pwm->hwpwm, 0); return 0; } - 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); - - /* 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); - - return 0; -} - -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_read(pca->regmap, PCA9685_PRESCALE, &val); + if (prescale != val) { + /* + * Putting the chip briefly into SLEEP mode + * at this point won't interfere with the + * pm_runtime framework, because the pm_runtime + * state is guaranteed active here. + */ + /* Put chip into sleep mode */ + pca9685_set_sleep_mode(pca, true); - regmap_write(pca->regmap, reg, 0); + /* Change the chip-wide output frequency */ + regmap_write(pca->regmap, PCA9685_PRESCALE, prescale); - /* - * 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); + /* Wake the chip up */ + pca9685_set_sleep_mode(pca, false); + } + duty = PCA9685_COUNTER_RANGE * state->duty_cycle; + duty = DIV_ROUND_UP_ULL(duty, state->period); + pca9685_pwm_set_duty(pca, pwm->hwpwm, duty); return 0; } -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); - - /* 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); -} - static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) { struct pca9685 *pca = to_pca(chip); @@ -422,15 +346,13 @@ static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) { struct pca9685 *pca = to_pca(chip); - pca9685_pwm_disable(chip, pwm); + pca9685_pwm_set_duty(pca, pwm->hwpwm, 0); pm_runtime_put(chip->dev); pca9685_pwm_clear_inuse(pca, pwm->hwpwm); } static const struct pwm_ops pca9685_pwm_ops = { - .enable = pca9685_pwm_enable, - .disable = pca9685_pwm_disable, - .config = pca9685_pwm_config, + .apply = pca9685_pwm_apply, .request = pca9685_pwm_request, .free = pca9685_pwm_free, .owner = THIS_MODULE, @@ -461,7 +383,6 @@ static int pca9685_pwm_probe(struct i2c_client *client, ret); return ret; } - pca->period_ns = PCA9685_DEFAULT_PERIOD; i2c_set_clientdata(client, pca); @@ -484,9 +405,9 @@ static int pca9685_pwm_probe(struct i2c_client *client, reg &= ~(MODE1_ALLCALL | MODE1_SUB1 | MODE1_SUB2 | MODE1_SUB3); regmap_write(pca->regmap, PCA9685_MODE1, reg); - /* Clear all "full off" bits */ - regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0); - regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0); + /* Reset OFF registers to POR default */ + regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, LED_FULL); + regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, LED_FULL); pca->chip.ops = &pca9685_pwm_ops; /* Add an extra channel for ALL_LED */ |