Hi Hemanth,
On Tue, Aug 30, 2011 at 12:27:17PM +0530, Hemanth V wrote:
> From: Hemanth V <[email protected]>
> Date: Fri, 26 Aug 2011 10:49:29 +0530
> Subject: [PATCH] Add PWM1 and PWM2 support to twl6030-pwm driver
>
> This patch adds support for PWM1/PWM2. TWL6030 PWM driver also
> supports Indicator LED PWM. Function pointers are defined for
> for init, enable, disable and configuration for both Indicator LED
> PWM (led_pwm) and PWM1/PWM2 (std_pwm)
Some comments on this code:
> +/* PWMs supported by driver */
> +#define PWM_ID_LED 1
> +#define PWM_ID_PWM1 2
> +#define PWM_ID_PWM2 3
I wish we could use enums here, but that's not what the PWM API is expecting.
> +int led_pwm_enable(struct pwm_device *pwm)
All your pwm_ops should be static now.
> {
> u8 val;
> int ret;
> @@ -95,9 +140,8 @@ int pwm_enable(struct pwm_device *pwm)
> twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, LED_PWM_CTRL2);
> return 0;
> }
> -EXPORT_SYMBOL(pwm_enable);
>
> -void pwm_disable(struct pwm_device *pwm)
> +void led_pwm_disable(struct pwm_device *pwm)
> {
> u8 val;
> int ret;
> @@ -120,37 +164,284 @@ void pwm_disable(struct pwm_device *pwm)
> }
> return;
> }
> -EXPORT_SYMBOL(pwm_disable);
>
> -struct pwm_device *pwm_request(int pwm_id, const char *label)
> +int led_pwm_init(struct pwm_device *pwm)
> {
> u8 val;
> int ret;
> +
> + val = PWM_CTRL2_DIS_PD | PWM_CTRL2_CURR_02 | PWM_CTRL2_SRC_VBUS |
> + PWM_CTRL2_MODE_HW;
> +
> + ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, LED_PWM_CTRL2);
> +
> + return ret;
> +}
> +
> +static struct pwm_ops pwm_led = {
> + .config = led_pwm_config,
> + .enable = led_pwm_enable,
> + .disable = led_pwm_disable,
> + .init = led_pwm_init,
> +};
> +
> +int std_pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
> +{
> + int ret = 0, level, pwm_id, reg;
> +
> + level = (duty_ns * PWM_CTRL1_MAX) / period_ns;
> + pwm_id = pwm->pwm_id;
> +
> + if (pwm_id == PWM_ID_PWM1)
> + reg = LED_PWM1ON;
> + else
> + reg = LED_PWM2ON;
This is not consistent with your:
if (PWM1)
else if (PWM2)
else
error
logic below.
Moreover, I'd rather use switch() here but that's more of a personal taste
than anything else.
> +struct pwm_device *pwm_request(int pwm_id, const char *label)
> +{
> + int ret, found = 0;
> struct pwm_device *pwm;
>
> + mutex_lock(&pwm_lock);
> +
> + list_for_each_entry(pwm, &pwm_list, node) {
> + if (pwm->pwm_id == pwm_id) {
> + found = 1;
> + break;
> + }
> + }
> +
> + if (found) {
> + if (pwm->use_count == 0) {
> + pwm->use_count++;
> + pwm->label = label;
> + } else {
> + pwm = ERR_PTR(-EBUSY);
> + }
I failed to understand the logic here. How can you have found == TRUE, and
use_count being 0 ? Also, don't you want to track the pwm users and disable it
when user_count is reaching 0 ? You're not doing that from pwm_free().
> + goto out;
You're leaving with the pwm_lock locked.
Cheers,
Samuel.
--
Intel Open Source Technology Centre
http://oss.intel.com/
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