#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
#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;
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)
{
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);
}
}
}
-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);
{
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,
ret);
return ret;
}
- pca->period_ns = PCA9685_DEFAULT_PERIOD;
i2c_set_clientdata(client, pca);
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 */