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
to_twl(struct pwm_chip * chip)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
twl4030_pwmled_config(struct pwm_chip * chip,struct pwm_device * pwm,int duty_ns,int period_ns)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
twl4030_pwmled_enable(struct pwm_chip * chip,struct pwm_device * pwm)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
twl4030_pwmled_disable(struct pwm_chip * chip,struct pwm_device * pwm)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
twl6030_pwmled_config(struct pwm_chip * chip,struct pwm_device * pwm,int duty_ns,int period_ns)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
twl6030_pwmled_enable(struct pwm_chip * chip,struct pwm_device * pwm)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
twl6030_pwmled_disable(struct pwm_chip * chip,struct pwm_device * pwm)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
twl6030_pwmled_request(struct pwm_chip * chip,struct pwm_device * pwm)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
twl6030_pwmled_free(struct pwm_chip * chip,struct pwm_device * pwm)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
twl_pwmled_probe(struct platform_device * pdev)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
twl_pwmled_remove(struct platform_device * pdev)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