diff options
Diffstat (limited to 'drivers/leds/leds-atmel-pwm.c')
-rw-r--r-- | drivers/leds/leds-atmel-pwm.c | 149 |
1 files changed, 0 insertions, 149 deletions
diff --git a/drivers/leds/leds-atmel-pwm.c b/drivers/leds/leds-atmel-pwm.c deleted file mode 100644 index 56cec8d6a2ac..000000000000 --- a/drivers/leds/leds-atmel-pwm.c +++ /dev/null @@ -1,149 +0,0 @@ -#include <linux/kernel.h> -#include <linux/platform_device.h> -#include <linux/leds.h> -#include <linux/io.h> -#include <linux/atmel_pwm.h> -#include <linux/slab.h> -#include <linux/module.h> - - -struct pwmled { - struct led_classdev cdev; - struct pwm_channel pwmc; - struct gpio_led *desc; - u32 mult; - u8 active_low; -}; - - -/* - * For simplicity, we use "brightness" as if it were a linear function - * of PWM duty cycle. However, a logarithmic function of duty cycle is - * probably a better match for perceived brightness: two is half as bright - * as four, four is half as bright as eight, etc - */ -static void pwmled_brightness(struct led_classdev *cdev, enum led_brightness b) -{ - struct pwmled *led; - - /* update the duty cycle for the *next* period */ - led = container_of(cdev, struct pwmled, cdev); - pwm_channel_writel(&led->pwmc, PWM_CUPD, led->mult * (unsigned) b); -} - -/* - * NOTE: we reuse the platform_data structure of GPIO leds, - * but repurpose its "gpio" number as a PWM channel number. - */ -static int pwmled_probe(struct platform_device *pdev) -{ - const struct gpio_led_platform_data *pdata; - struct pwmled *leds; - int i; - int status; - - pdata = dev_get_platdata(&pdev->dev); - if (!pdata || pdata->num_leds < 1) - return -ENODEV; - - leds = devm_kzalloc(&pdev->dev, pdata->num_leds * sizeof(*leds), - GFP_KERNEL); - if (!leds) - return -ENOMEM; - - for (i = 0; i < pdata->num_leds; i++) { - struct pwmled *led = leds + i; - const struct gpio_led *dat = pdata->leds + i; - u32 tmp; - - led->cdev.name = dat->name; - led->cdev.brightness = LED_OFF; - led->cdev.brightness_set = pwmled_brightness; - led->cdev.default_trigger = dat->default_trigger; - - led->active_low = dat->active_low; - - status = pwm_channel_alloc(dat->gpio, &led->pwmc); - if (status < 0) - goto err; - - /* - * Prescale clock by 2^x, so PWM counts in low MHz. - * Start each cycle with the LED active, so increasing - * the duty cycle gives us more time on (== brighter). - */ - tmp = 5; - if (!led->active_low) - tmp |= PWM_CPR_CPOL; - pwm_channel_writel(&led->pwmc, PWM_CMR, tmp); - - /* - * Pick a period so PWM cycles at 100+ Hz; and a multiplier - * for scaling duty cycle: brightness * mult. - */ - tmp = (led->pwmc.mck / (1 << 5)) / 100; - tmp /= 255; - led->mult = tmp; - pwm_channel_writel(&led->pwmc, PWM_CDTY, - led->cdev.brightness * 255); - pwm_channel_writel(&led->pwmc, PWM_CPRD, - LED_FULL * tmp); - - pwm_channel_enable(&led->pwmc); - - /* Hand it over to the LED framework */ - status = led_classdev_register(&pdev->dev, &led->cdev); - if (status < 0) { - pwm_channel_free(&led->pwmc); - goto err; - } - } - - platform_set_drvdata(pdev, leds); - return 0; - -err: - if (i > 0) { - for (i = i - 1; i >= 0; i--) { - led_classdev_unregister(&leds[i].cdev); - pwm_channel_free(&leds[i].pwmc); - } - } - - return status; -} - -static int pwmled_remove(struct platform_device *pdev) -{ - const struct gpio_led_platform_data *pdata; - struct pwmled *leds; - unsigned i; - - pdata = dev_get_platdata(&pdev->dev); - leds = platform_get_drvdata(pdev); - - for (i = 0; i < pdata->num_leds; i++) { - struct pwmled *led = leds + i; - - led_classdev_unregister(&led->cdev); - pwm_channel_free(&led->pwmc); - } - - return 0; -} - -static struct platform_driver pwmled_driver = { - .driver = { - .name = "leds-atmel-pwm", - .owner = THIS_MODULE, - }, - /* REVISIT add suspend() and resume() methods */ - .probe = pwmled_probe, - .remove = pwmled_remove, -}; - -module_platform_driver(pwmled_driver); - -MODULE_DESCRIPTION("Driver for LEDs with PWM-controlled brightness"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:leds-atmel-pwm"); |