Thierry Reding wrote at Wednesday, February 22, 2012 8:17 AM:
> This commit adds a generic PWM framework driver for the PWFM controller
> found on NVIDIA Tegra SoCs. The driver is based on code from the
> Chromium kernel tree and was originally written by Gary King (NVIDIA)
> and later modified by Simon Que (Chromium).
> diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c
> +static int tegra_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
> + /*
> + * Convert from duty_ns / period_ns to a fixed number of duty
> + * ticks per (1 << PWM_DUTY_WIDTH) cycles.
> + */
> + c = duty_ns * ((1 << PWM_DUTY_WIDTH) - 1);
The driver in ChromeOS has the following extra line here:
c += (period_ns / 2);
and the following extra line in the comment above:
Also, make sure to round to the nearest integer during division.
I don't know the HW well enough to know if that line should be present?
Otherwise, this looks similar enough to the ChromeOS driver, so:
Acked-by: Stephen Warren <[email protected]>
--
nvpublic
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