Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

Linux/drivers/pwm/pwm-twl-led.c

  1 /*
  2  * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
  3  *
  4  * Copyright (C) 2012 Texas Instruments
  5  * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
  6  *
  7  * This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
  8  * Hemanth V <hemanthv@ti.com>
  9  *
 10  * This program is free software; you can redistribute it and/or modify it
 11  * under the terms of the GNU General Public License version 2 as published by
 12  * the Free Software Foundation.
 13  *
 14  * This program is distributed in the hope that it will be useful, but WITHOUT
 15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 16  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 17  * more details.
 18  *
 19  * You should have received a copy of the GNU General Public License along with
 20  * this program.  If not, see <http://www.gnu.org/licenses/>.
 21  */
 22 
 23 #include <linux/module.h>
 24 #include <linux/of.h>
 25 #include <linux/platform_device.h>
 26 #include <linux/pwm.h>
 27 #include <linux/i2c/twl.h>
 28 #include <linux/slab.h>
 29 
 30 /*
 31  * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
 32  * To generate the signal on TWL4030:
 33  *  - LEDA uses PWMA
 34  *  - LEDB uses PWMB
 35  * TWL6030 has one LED pin with dedicated LEDPWM
 36  */
 37 
 38 #define TWL4030_LED_MAX         0x7f
 39 #define TWL6030_LED_MAX         0xff
 40 
 41 /* Registers, bits and macro for TWL4030 */
 42 #define TWL4030_LEDEN_REG       0x00
 43 #define TWL4030_PWMA_REG        0x01
 44 
 45 #define TWL4030_LEDXON          (1 << 0)
 46 #define TWL4030_LEDXPWM         (1 << 4)
 47 #define TWL4030_LED_PINS        (TWL4030_LEDXON | TWL4030_LEDXPWM)
 48 #define TWL4030_LED_TOGGLE(led, x)      ((x) << (led))
 49 
 50 /* Register, bits and macro for TWL6030 */
 51 #define TWL6030_LED_PWM_CTRL1   0xf4
 52 #define TWL6030_LED_PWM_CTRL2   0xf5
 53 
 54 #define TWL6040_LED_MODE_HW     0x00
 55 #define TWL6040_LED_MODE_ON     0x01
 56 #define TWL6040_LED_MODE_OFF    0x02
 57 #define TWL6040_LED_MODE_MASK   0x03
 58 
 59 struct twl_pwmled_chip {
 60         struct pwm_chip chip;
 61         struct mutex mutex;
 62 };
 63 
 64 static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
 65 {
 66         return container_of(chip, struct twl_pwmled_chip, chip);
 67 }
 68 
 69 static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
 70                               int duty_ns, int period_ns)
 71 {
 72         int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
 73         u8 pwm_config[2] = { 1, 0 };
 74         int base, ret;
 75 
 76         /*
 77          * To configure the duty period:
 78          * On-cycle is set to 1 (the minimum allowed value)
 79          * The off time of 0 is not configurable, so the mapping is:
 80          * 0 -> off cycle = 2,
 81          * 1 -> off cycle = 2,
 82          * 2 -> off cycle = 3,
 83          * 126 - > off cycle 127,
 84          * 127 - > off cycle 1
 85          * When on cycle == off cycle the PWM will be always on
 86          */
 87         if (duty_cycle == 1)
 88                 duty_cycle = 2;
 89         else if (duty_cycle > TWL4030_LED_MAX)
 90                 duty_cycle = 1;
 91 
 92         base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;
 93 
 94         pwm_config[1] = duty_cycle;
 95 
 96         ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
 97         if (ret < 0)
 98                 dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
 99 
100         return ret;
101 }
102 
103 static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
104 {
105         struct twl_pwmled_chip *twl = to_twl(chip);
106         int ret;
107         u8 val;
108 
109         mutex_lock(&twl->mutex);
110         ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
111         if (ret < 0) {
112                 dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
113                 goto out;
114         }
115 
116         val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
117 
118         ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
119         if (ret < 0)
120                 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
121 
122 out:
123         mutex_unlock(&twl->mutex);
124         return ret;
125 }
126 
127 static void twl4030_pwmled_disable(struct pwm_chip *chip,
128                                    struct pwm_device *pwm)
129 {
130         struct twl_pwmled_chip *twl = to_twl(chip);
131         int ret;
132         u8 val;
133 
134         mutex_lock(&twl->mutex);
135         ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
136         if (ret < 0) {
137                 dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
138                 goto out;
139         }
140 
141         val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
142 
143         ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
144         if (ret < 0)
145                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
146 
147 out:
148         mutex_unlock(&twl->mutex);
149 }
150 
151 static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
152                               int duty_ns, int period_ns)
153 {
154         int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
155         u8 on_time;
156         int ret;
157 
158         on_time = duty_cycle & 0xff;
159 
160         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
161                                TWL6030_LED_PWM_CTRL1);
162         if (ret < 0)
163                 dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
164 
165         return ret;
166 }
167 
168 static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
169 {
170         struct twl_pwmled_chip *twl = to_twl(chip);
171         int ret;
172         u8 val;
173 
174         mutex_lock(&twl->mutex);
175         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
176         if (ret < 0) {
177                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
178                         pwm->label);
179                 goto out;
180         }
181 
182         val &= ~TWL6040_LED_MODE_MASK;
183         val |= TWL6040_LED_MODE_ON;
184 
185         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
186         if (ret < 0)
187                 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
188 
189 out:
190         mutex_unlock(&twl->mutex);
191         return ret;
192 }
193 
194 static void twl6030_pwmled_disable(struct pwm_chip *chip,
195                                    struct pwm_device *pwm)
196 {
197         struct twl_pwmled_chip *twl = to_twl(chip);
198         int ret;
199         u8 val;
200 
201         mutex_lock(&twl->mutex);
202         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
203         if (ret < 0) {
204                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
205                         pwm->label);
206                 goto out;
207         }
208 
209         val &= ~TWL6040_LED_MODE_MASK;
210         val |= TWL6040_LED_MODE_OFF;
211 
212         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
213         if (ret < 0)
214                 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
215 
216 out:
217         mutex_unlock(&twl->mutex);
218 }
219 
220 static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
221 {
222         struct twl_pwmled_chip *twl = to_twl(chip);
223         int ret;
224         u8 val;
225 
226         mutex_lock(&twl->mutex);
227         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
228         if (ret < 0) {
229                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
230                         pwm->label);
231                 goto out;
232         }
233 
234         val &= ~TWL6040_LED_MODE_MASK;
235         val |= TWL6040_LED_MODE_OFF;
236 
237         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
238         if (ret < 0)
239                 dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
240 
241 out:
242         mutex_unlock(&twl->mutex);
243         return ret;
244 }
245 
246 static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
247 {
248         struct twl_pwmled_chip *twl = to_twl(chip);
249         int ret;
250         u8 val;
251 
252         mutex_lock(&twl->mutex);
253         ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
254         if (ret < 0) {
255                 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
256                         pwm->label);
257                 goto out;
258         }
259 
260         val &= ~TWL6040_LED_MODE_MASK;
261         val |= TWL6040_LED_MODE_HW;
262 
263         ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
264         if (ret < 0)
265                 dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
266 
267 out:
268         mutex_unlock(&twl->mutex);
269 }
270 
271 static const struct pwm_ops twl4030_pwmled_ops = {
272         .enable = twl4030_pwmled_enable,
273         .disable = twl4030_pwmled_disable,
274         .config = twl4030_pwmled_config,
275         .owner = THIS_MODULE,
276 };
277 
278 static const struct pwm_ops twl6030_pwmled_ops = {
279         .enable = twl6030_pwmled_enable,
280         .disable = twl6030_pwmled_disable,
281         .config = twl6030_pwmled_config,
282         .request = twl6030_pwmled_request,
283         .free = twl6030_pwmled_free,
284         .owner = THIS_MODULE,
285 };
286 
287 static int twl_pwmled_probe(struct platform_device *pdev)
288 {
289         struct twl_pwmled_chip *twl;
290         int ret;
291 
292         twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
293         if (!twl)
294                 return -ENOMEM;
295 
296         if (twl_class_is_4030()) {
297                 twl->chip.ops = &twl4030_pwmled_ops;
298                 twl->chip.npwm = 2;
299         } else {
300                 twl->chip.ops = &twl6030_pwmled_ops;
301                 twl->chip.npwm = 1;
302         }
303 
304         twl->chip.dev = &pdev->dev;
305         twl->chip.base = -1;
306         twl->chip.can_sleep = true;
307 
308         mutex_init(&twl->mutex);
309 
310         ret = pwmchip_add(&twl->chip);
311         if (ret < 0)
312                 return ret;
313 
314         platform_set_drvdata(pdev, twl);
315 
316         return 0;
317 }
318 
319 static int twl_pwmled_remove(struct platform_device *pdev)
320 {
321         struct twl_pwmled_chip *twl = platform_get_drvdata(pdev);
322 
323         return pwmchip_remove(&twl->chip);
324 }
325 
326 #ifdef CONFIG_OF
327 static const struct of_device_id twl_pwmled_of_match[] = {
328         { .compatible = "ti,twl4030-pwmled" },
329         { .compatible = "ti,twl6030-pwmled" },
330         { },
331 };
332 MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
333 #endif
334 
335 static struct platform_driver twl_pwmled_driver = {
336         .driver = {
337                 .name = "twl-pwmled",
338                 .of_match_table = of_match_ptr(twl_pwmled_of_match),
339         },
340         .probe = twl_pwmled_probe,
341         .remove = twl_pwmled_remove,
342 };
343 module_platform_driver(twl_pwmled_driver);
344 
345 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
346 MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
347 MODULE_ALIAS("platform:twl-pwmled");
348 MODULE_LICENSE("GPL");
349 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us