diff options
| author | Alper Nebi Yasak <alpernebiyasak@gmail.com> | 2020-10-22 23:49:27 +0300 |
|---|---|---|
| committer | Anatolij Gustschin <agust@denx.de> | 2021-04-10 16:08:39 +0200 |
| commit | 1b9ee2882e6bd1c17ab2ec86249aa0347af68242 (patch) | |
| tree | 97c0a555eae842b114c8fbbc22e2b1acd48c8773 /drivers/misc | |
| parent | fefa713b1843cf13d3132bfe0cf27710938c5d92 (diff) | |
pwm: Add a driver for Chrome OS EC PWM
This PWM is used in rk3399-gru-bob and rk3399-gru-kevin to control
the display brightness. We can only change the duty cycle, so on
set_config() we just try to match the duty cycle that dividing duty_ns
by period_ns gives us. To disable, we set the duty cycle to zero while
keeping the old value for when we want to re-enable it.
The cros_ec_set_pwm_duty() function is taken from Depthcharge's
cros_ec_set_bl_pwm_duty() but modified to use the generic pwm type.
The driver itself is very loosely based on rk_pwm.c for the general pwm
driver structure.
The devicetree binding file is from Linux, before it was converted to
YAML at 5df5a577a6b4 ("dt-bindings: pwm: Convert google,cros-ec-pwm.txt
to YAML format") in their repo.
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/cros_ec.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/misc/cros_ec.c b/drivers/misc/cros_ec.c index ebfa7c41c2..7904d5cc72 100644 --- a/drivers/misc/cros_ec.c +++ b/drivers/misc/cros_ec.c @@ -1170,6 +1170,23 @@ int cros_ec_battery_cutoff(struct udevice *dev, uint8_t flags) return 0; } +int cros_ec_set_pwm_duty(struct udevice *dev, uint8_t index, uint16_t duty) +{ + struct ec_params_pwm_set_duty p; + int ret; + + p.duty = duty; + p.pwm_type = EC_PWM_TYPE_GENERIC; + p.index = index; + + ret = ec_command(dev, EC_CMD_PWM_SET_DUTY, 0, &p, sizeof(p), + NULL, 0); + if (ret < 0) + return ret; + + return 0; +} + int cros_ec_set_ldo(struct udevice *dev, uint8_t index, uint8_t state) { struct ec_params_ldo_set params; |