2 * TWL4030 PWM controlled LED driver (LEDA, LEDB, PWM0, PWM1)
4 * Author: Gražvydas Ignotas <notasas@gmail.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/workqueue.h>
15 #include <linux/platform_device.h>
16 #include <linux/leds.h>
17 #include <linux/leds_pwm.h>
18 #include <linux/i2c/twl.h>
19 #include <linux/slab.h>
21 #define TWL_INTBR_GPBR1 0x0c
22 #define TWL_INTBR_PMBR1 0x0d
24 #define TWL4030_PWMx_PWMxON 0x00
25 #define TWL4030_PWMx_PWMxOFF 0x01
26 #define TWL4030_LED_LEDEN 0x00
28 #define GPBR1_PWM0_CLK_ENABLE BIT(0)
29 #define GPBR1_PWM1_CLK_ENABLE BIT(1)
30 #define GPBR1_PWM0_ENABLE BIT(2)
31 #define GPBR1_PWM1_ENABLE BIT(3)
34 #define LEDEN_LEDAON BIT(0)
35 #define LEDEN_LEDBON BIT(1)
36 #define LEDEN_LEDAPWM BIT(4)
37 #define LEDEN_LEDBPWM BIT(5)
39 #define LED_UNKNOWN -1
48 struct twl4030_pwmled {
49 struct led_classdev cdev;
50 void (*enable)(enum twl4030_led led, bool enable);
51 enum led_brightness new_brightness;
52 enum led_brightness old_brightness;
55 struct work_struct work;
58 static void twl4030_enable_ledab(enum twl4030_led led, bool enable)
62 if (led == TWL4030_LEDA)
63 bits = LEDEN_LEDAON | LEDEN_LEDAPWM;
65 bits = LEDEN_LEDBON | LEDEN_LEDBPWM;
68 twl_i2c_rmw_u8(TWL4030_MODULE_LED, 0, bits, TWL4030_LED_LEDEN);
70 twl_i2c_rmw_u8(TWL4030_MODULE_LED, bits, 0, TWL4030_LED_LEDEN);
73 static void twl4030_enable_pwm01(enum twl4030_led led, bool enable)
77 if (led == TWL4030_PWM0) {
78 enbit = GPBR1_PWM0_ENABLE;
79 clkbit = GPBR1_PWM0_CLK_ENABLE;
81 enbit = GPBR1_PWM1_ENABLE;
82 clkbit = GPBR1_PWM1_CLK_ENABLE;
86 /* first enable clock, then PWM out */
87 twl_i2c_rmw_u8(TWL4030_MODULE_INTBR,
88 enbit, clkbit, TWL_INTBR_GPBR1);
89 twl_i2c_rmw_u8(TWL4030_MODULE_INTBR,
90 0, enbit, TWL_INTBR_GPBR1);
92 /* first disable PWM output, then clock */
93 twl_i2c_rmw_u8(TWL4030_MODULE_INTBR,
94 enbit, 0, TWL_INTBR_GPBR1);
95 twl_i2c_rmw_u8(TWL4030_MODULE_INTBR,
96 clkbit, 0, TWL_INTBR_GPBR1);
100 static void twl4030_pwmled_work(struct work_struct *work)
102 struct twl4030_pwmled *led;
105 led = container_of(work, struct twl4030_pwmled, work);
107 if (led->new_brightness == LED_OFF) {
108 if (led->old_brightness != LED_OFF)
109 led->enable(led->id, 0);
113 val = led->new_brightness * 0x7f / LED_FULL;
114 /* avoid 0: on = off = 0 means full brightness */
118 twl_i2c_write_u8(led->module, val, TWL4030_PWMx_PWMxOFF);
120 if (led->old_brightness == LED_OFF || led->old_brightness == LED_UNKNOWN)
121 led->enable(led->id, 1);
124 led->old_brightness = led->new_brightness;
127 static void twl4030_pwmled_brightness(struct led_classdev *cdev,
128 enum led_brightness b)
130 struct twl4030_pwmled *led;
132 led = container_of(cdev, struct twl4030_pwmled, cdev);
133 led->new_brightness = b;
134 schedule_work(&led->work);
137 static int __devinit twl4030_pwmled_probe(struct platform_device *pdev)
139 const struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
140 struct twl4030_pwmled *led, *leds;
144 pdata = pdev->dev.platform_data;
145 if (!pdata || pdata->num_leds < 1 || pdata->num_leds > 4)
148 leds = kcalloc(pdata->num_leds, sizeof(*leds), GFP_KERNEL);
152 for (i = 0; i < pdata->num_leds; i++) {
154 led->cdev.name = pdata->leds[i].name;
155 led->cdev.brightness = LED_OFF;
156 led->cdev.brightness_set = twl4030_pwmled_brightness;
157 led->cdev.default_trigger = pdata->leds[i].default_trigger;
158 led->id = pdata->leds[i].pwm_id;
159 led->old_brightness = LED_UNKNOWN;
161 switch (pdata->leds[i].pwm_id) {
163 led->module = TWL4030_MODULE_PWMA;
164 led->enable = twl4030_enable_ledab;
167 led->module = TWL4030_MODULE_PWMB;
168 led->enable = twl4030_enable_ledab;
171 led->module = TWL4030_MODULE_PWM0;
172 led->enable = twl4030_enable_pwm01;
173 /* enable PWM0 in pin mux */
174 twl_i2c_rmw_u8(TWL4030_MODULE_INTBR,
175 0x0c, 0x04, TWL_INTBR_PMBR1);
176 /* enable PWM clock for initial write */
177 twl_i2c_rmw_u8(TWL4030_MODULE_INTBR,
178 0, GPBR1_PWM0_CLK_ENABLE, TWL_INTBR_GPBR1);
181 led->module = TWL4030_MODULE_PWM1;
182 led->enable = twl4030_enable_pwm01;
183 twl_i2c_rmw_u8(TWL4030_MODULE_INTBR,
184 0, 0x30, TWL_INTBR_PMBR1);
185 twl_i2c_rmw_u8(TWL4030_MODULE_INTBR,
186 0, GPBR1_PWM1_CLK_ENABLE, TWL_INTBR_GPBR1);
189 dev_err(&pdev->dev, "invalid pwm_id: %d\n",
190 pdata->leds->pwm_id);
194 INIT_WORK(&led->work, twl4030_pwmled_work);
196 twl_i2c_write_u8(led->module, 0, TWL4030_PWMx_PWMxON);
197 led->new_brightness = LED_OFF;
198 twl4030_pwmled_work(&led->work);
200 /* Hand it over to the LED framework */
201 ret = led_classdev_register(&pdev->dev, &led->cdev);
206 platform_set_drvdata(pdev, leds);
210 for (--i; i >= 0; i--)
211 led_classdev_unregister(&leds[i].cdev);
217 static int __devexit twl4030_pwmled_remove(struct platform_device *pdev)
219 const struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
220 struct twl4030_pwmled *leds;
223 leds = platform_get_drvdata(pdev);
225 for (i = 0; i < pdata->num_leds; i++) {
226 led_classdev_unregister(&leds[i].cdev);
227 cancel_work_sync(&leds[i].work);
231 platform_set_drvdata(pdev, NULL);
235 static struct platform_driver twl4030_pwmled_driver = {
237 .name = "leds-twl4030-pwm",
238 .owner = THIS_MODULE,
240 .probe = twl4030_pwmled_probe,
241 .remove = __devexit_p(twl4030_pwmled_remove),
244 static int __init twl4030_pwm_init(void)
246 return platform_driver_register(&twl4030_pwmled_driver);
248 module_init(twl4030_pwm_init);
250 static void __exit twl4030_pwm_exit(void)
252 platform_driver_unregister(&twl4030_pwmled_driver);
254 module_exit(twl4030_pwm_exit);
256 MODULE_AUTHOR("Gražvydas Ignotas");
257 MODULE_DESCRIPTION("Driver for TWL4030 PWM controlled LEDs");
258 MODULE_LICENSE("GPL");
259 MODULE_ALIAS("platform:leds-twl4030-pwm");