1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
4 *
5 * Copyright (C) 2012 Texas Instruments
6 * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
7 *
8 * This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
9 * Hemanth V <hemanthv@ti.com>
10 */
11
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/platform_device.h>
15 #include <linux/pwm.h>
16 #include <linux/mfd/twl.h>
17 #include <linux/slab.h>
18
19 /*
20 * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
21 * To generate the signal on TWL4030:
22 * - LEDA uses PWMA
23 * - LEDB uses PWMB
24 * TWL6030 has one LED pin with dedicated LEDPWM
25 */
26
27 #define TWL4030_LED_MAX 0x7f
28 #define TWL6030_LED_MAX 0xff
29
30 /* Registers, bits and macro for TWL4030 */
31 #define TWL4030_LEDEN_REG 0x00
32 #define TWL4030_PWMA_REG 0x01
33
34 #define TWL4030_LEDXON (1 << 0)
35 #define TWL4030_LEDXPWM (1 << 4)
36 #define TWL4030_LED_PINS (TWL4030_LEDXON | TWL4030_LEDXPWM)
37 #define TWL4030_LED_TOGGLE(led, x) ((x) << (led))
38
39 /* Register, bits and macro for TWL6030 */
40 #define TWL6030_LED_PWM_CTRL1 0xf4
41 #define TWL6030_LED_PWM_CTRL2 0xf5
42
43 #define TWL6040_LED_MODE_HW 0x00
44 #define TWL6040_LED_MODE_ON 0x01
45 #define TWL6040_LED_MODE_OFF 0x02
46 #define TWL6040_LED_MODE_MASK 0x03
47
48 struct twl_pwmled_chip {
49 struct pwm_chip chip;
50 struct mutex mutex;
51 };
52
to_twl(struct pwm_chip * chip)53 static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
54 {
55 return container_of(chip, struct twl_pwmled_chip, chip);
56 }
57
twl4030_pwmled_config(struct pwm_chip * chip,struct pwm_device * pwm,int duty_ns,int period_ns)58 static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
59 int duty_ns, int period_ns)
60 {
61 int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
62 u8 pwm_config[2] = { 1, 0 };
63 int base, ret;
64
65 /*
66 * To configure the duty period:
67 * On-cycle is set to 1 (the minimum allowed value)
68 * The off time of 0 is not configurable, so the mapping is:
69 * 0 -> off cycle = 2,
70 * 1 -> off cycle = 2,
71 * 2 -> off cycle = 3,
72 * 126 - > off cycle 127,
73 * 127 - > off cycle 1
74 * When on cycle == off cycle the PWM will be always on
75 */
76 if (duty_cycle == 1)
77 duty_cycle = 2;
78 else if (duty_cycle > TWL4030_LED_MAX)
79 duty_cycle = 1;
80
81 base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;
82
83 pwm_config[1] = duty_cycle;
84
85 ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
86 if (ret < 0)
87 dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
88
89 return ret;
90 }
91
twl4030_pwmled_enable(struct pwm_chip * chip,struct pwm_device * pwm)92 static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
93 {
94 struct twl_pwmled_chip *twl = to_twl(chip);
95 int ret;
96 u8 val;
97
98 mutex_lock(&twl->mutex);
99 ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
100 if (ret < 0) {
101 dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
102 goto out;
103 }
104
105 val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
106
107 ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
108 if (ret < 0)
109 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
110
111 out:
112 mutex_unlock(&twl->mutex);
113 return ret;
114 }
115
twl4030_pwmled_disable(struct pwm_chip * chip,struct pwm_device * pwm)116 static void twl4030_pwmled_disable(struct pwm_chip *chip,
117 struct pwm_device *pwm)
118 {
119 struct twl_pwmled_chip *twl = to_twl(chip);
120 int ret;
121 u8 val;
122
123 mutex_lock(&twl->mutex);
124 ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
125 if (ret < 0) {
126 dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
127 goto out;
128 }
129
130 val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
131
132 ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
133 if (ret < 0)
134 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
135
136 out:
137 mutex_unlock(&twl->mutex);
138 }
139
twl6030_pwmled_config(struct pwm_chip * chip,struct pwm_device * pwm,int duty_ns,int period_ns)140 static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
141 int duty_ns, int period_ns)
142 {
143 int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
144 u8 on_time;
145 int ret;
146
147 on_time = duty_cycle & 0xff;
148
149 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
150 TWL6030_LED_PWM_CTRL1);
151 if (ret < 0)
152 dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
153
154 return ret;
155 }
156
twl6030_pwmled_enable(struct pwm_chip * chip,struct pwm_device * pwm)157 static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
158 {
159 struct twl_pwmled_chip *twl = to_twl(chip);
160 int ret;
161 u8 val;
162
163 mutex_lock(&twl->mutex);
164 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
165 if (ret < 0) {
166 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
167 pwm->label);
168 goto out;
169 }
170
171 val &= ~TWL6040_LED_MODE_MASK;
172 val |= TWL6040_LED_MODE_ON;
173
174 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
175 if (ret < 0)
176 dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
177
178 out:
179 mutex_unlock(&twl->mutex);
180 return ret;
181 }
182
twl6030_pwmled_disable(struct pwm_chip * chip,struct pwm_device * pwm)183 static void twl6030_pwmled_disable(struct pwm_chip *chip,
184 struct pwm_device *pwm)
185 {
186 struct twl_pwmled_chip *twl = to_twl(chip);
187 int ret;
188 u8 val;
189
190 mutex_lock(&twl->mutex);
191 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
192 if (ret < 0) {
193 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
194 pwm->label);
195 goto out;
196 }
197
198 val &= ~TWL6040_LED_MODE_MASK;
199 val |= TWL6040_LED_MODE_OFF;
200
201 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
202 if (ret < 0)
203 dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
204
205 out:
206 mutex_unlock(&twl->mutex);
207 }
208
twl6030_pwmled_request(struct pwm_chip * chip,struct pwm_device * pwm)209 static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
210 {
211 struct twl_pwmled_chip *twl = to_twl(chip);
212 int ret;
213 u8 val;
214
215 mutex_lock(&twl->mutex);
216 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
217 if (ret < 0) {
218 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
219 pwm->label);
220 goto out;
221 }
222
223 val &= ~TWL6040_LED_MODE_MASK;
224 val |= TWL6040_LED_MODE_OFF;
225
226 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
227 if (ret < 0)
228 dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
229
230 out:
231 mutex_unlock(&twl->mutex);
232 return ret;
233 }
234
twl6030_pwmled_free(struct pwm_chip * chip,struct pwm_device * pwm)235 static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
236 {
237 struct twl_pwmled_chip *twl = to_twl(chip);
238 int ret;
239 u8 val;
240
241 mutex_lock(&twl->mutex);
242 ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
243 if (ret < 0) {
244 dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
245 pwm->label);
246 goto out;
247 }
248
249 val &= ~TWL6040_LED_MODE_MASK;
250 val |= TWL6040_LED_MODE_HW;
251
252 ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
253 if (ret < 0)
254 dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
255
256 out:
257 mutex_unlock(&twl->mutex);
258 }
259
260 static const struct pwm_ops twl4030_pwmled_ops = {
261 .enable = twl4030_pwmled_enable,
262 .disable = twl4030_pwmled_disable,
263 .config = twl4030_pwmled_config,
264 .owner = THIS_MODULE,
265 };
266
267 static const struct pwm_ops twl6030_pwmled_ops = {
268 .enable = twl6030_pwmled_enable,
269 .disable = twl6030_pwmled_disable,
270 .config = twl6030_pwmled_config,
271 .request = twl6030_pwmled_request,
272 .free = twl6030_pwmled_free,
273 .owner = THIS_MODULE,
274 };
275
twl_pwmled_probe(struct platform_device * pdev)276 static int twl_pwmled_probe(struct platform_device *pdev)
277 {
278 struct twl_pwmled_chip *twl;
279
280 twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
281 if (!twl)
282 return -ENOMEM;
283
284 if (twl_class_is_4030()) {
285 twl->chip.ops = &twl4030_pwmled_ops;
286 twl->chip.npwm = 2;
287 } else {
288 twl->chip.ops = &twl6030_pwmled_ops;
289 twl->chip.npwm = 1;
290 }
291
292 twl->chip.dev = &pdev->dev;
293
294 mutex_init(&twl->mutex);
295
296 return devm_pwmchip_add(&pdev->dev, &twl->chip);
297 }
298
299 #ifdef CONFIG_OF
300 static const struct of_device_id twl_pwmled_of_match[] = {
301 { .compatible = "ti,twl4030-pwmled" },
302 { .compatible = "ti,twl6030-pwmled" },
303 { },
304 };
305 MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
306 #endif
307
308 static struct platform_driver twl_pwmled_driver = {
309 .driver = {
310 .name = "twl-pwmled",
311 .of_match_table = of_match_ptr(twl_pwmled_of_match),
312 },
313 .probe = twl_pwmled_probe,
314 };
315 module_platform_driver(twl_pwmled_driver);
316
317 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
318 MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
319 MODULE_ALIAS("platform:twl-pwmled");
320 MODULE_LICENSE("GPL");
321