From 83af24027b3df1af5c5a9aa9adcdcfeb3429d3be Mon Sep 17 00:00:00 2001 From: "Philip, Avinash" Date: Wed, 21 Nov 2012 13:10:44 +0530 Subject: pwm: Device tree support for PWM polarity Add support for encoding PWM properties in bit encoded form with of_pwm_xlate_with_flags() function support. Platforms require platform specific PWM properties has to populate in 3rd cell of the pwm-specifier and PWM driver should also set .of_xlate support with this function. Currently PWM property polarity encoded in bit position 0 of the third cell in pwm-specifier. Signed-off-by: Philip, Avinash Acked-by: Grant Likely Signed-off-by: Thierry Reding --- drivers/pwm/core.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'drivers/pwm') diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index f5acdaa52707..780cb6b8a8f0 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -32,6 +32,9 @@ #define MAX_PWMS 1024 +/* flags in the third cell of the DT PWM specifier */ +#define PWM_SPEC_POLARITY (1 << 0) + static DEFINE_MUTEX(pwm_lookup_lock); static LIST_HEAD(pwm_lookup_list); static DEFINE_MUTEX(pwm_lock); @@ -129,6 +132,31 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) return 0; } +struct pwm_device * +of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) +{ + struct pwm_device *pwm; + + if (pc->of_pwm_n_cells < 3) + return ERR_PTR(-EINVAL); + + if (args->args[0] >= pc->npwm) + return ERR_PTR(-EINVAL); + + pwm = pwm_request_from_chip(pc, args->args[0], NULL); + if (IS_ERR(pwm)) + return pwm; + + pwm_set_period(pwm, args->args[1]); + + if (args->args[2] & PWM_SPEC_POLARITY) + pwm_set_polarity(pwm, PWM_POLARITY_INVERSED); + else + pwm_set_polarity(pwm, PWM_POLARITY_NORMAL); + + return pwm; +} + static struct pwm_device * of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) { -- cgit v1.2.3