xref: /openbmc/linux/drivers/pwm/pwm-twl.c (revision e23feb16)
1 /*
2  * Driver for TWL4030/6030 Generic Pulse Width Modulator
3  *
4  * Copyright (C) 2012 Texas Instruments
5  * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License version 2 as published by
9  * the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <linux/module.h>
21 #include <linux/platform_device.h>
22 #include <linux/pwm.h>
23 #include <linux/i2c/twl.h>
24 #include <linux/slab.h>
25 
26 /*
27  * This driver handles the PWMs of TWL4030 and TWL6030.
28  * The TRM names for the PWMs on TWL4030 are: PWM0, PWM1
29  * TWL6030 also have two PWMs named in the TRM as PWM1, PWM2
30  */
31 
32 #define TWL_PWM_MAX		0x7f
33 
34 /* Registers, bits and macro for TWL4030 */
35 #define TWL4030_GPBR1_REG	0x0c
36 #define TWL4030_PMBR1_REG	0x0d
37 
38 /* GPBR1 register bits */
39 #define TWL4030_PWMXCLK_ENABLE	(1 << 0)
40 #define TWL4030_PWMX_ENABLE	(1 << 2)
41 #define TWL4030_PWMX_BITS	(TWL4030_PWMX_ENABLE | TWL4030_PWMXCLK_ENABLE)
42 #define TWL4030_PWM_TOGGLE(pwm, x)	((x) << (pwm))
43 
44 /* PMBR1 register bits */
45 #define TWL4030_GPIO6_PWM0_MUTE_MASK		(0x03 << 2)
46 #define TWL4030_GPIO6_PWM0_MUTE_PWM0		(0x01 << 2)
47 #define TWL4030_GPIO7_VIBRASYNC_PWM1_MASK	(0x03 << 4)
48 #define TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1	(0x03 << 4)
49 
50 /* Register, bits and macro for TWL6030 */
51 #define TWL6030_TOGGLE3_REG	0x92
52 
53 #define TWL6030_PWMXR		(1 << 0)
54 #define TWL6030_PWMXS		(1 << 1)
55 #define TWL6030_PWMXEN		(1 << 2)
56 #define TWL6030_PWM_TOGGLE(pwm, x)	((x) << (pwm * 3))
57 
58 struct twl_pwm_chip {
59 	struct pwm_chip chip;
60 	struct mutex mutex;
61 	u8 twl6030_toggle3;
62 	u8 twl4030_pwm_mux;
63 };
64 
65 static inline struct twl_pwm_chip *to_twl(struct pwm_chip *chip)
66 {
67 	return container_of(chip, struct twl_pwm_chip, chip);
68 }
69 
70 static int twl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
71 			      int duty_ns, int period_ns)
72 {
73 	int duty_cycle = DIV_ROUND_UP(duty_ns * TWL_PWM_MAX, period_ns) + 1;
74 	u8 pwm_config[2] = { 1, 0 };
75 	int base, ret;
76 
77 	/*
78 	 * To configure the duty period:
79 	 * On-cycle is set to 1 (the minimum allowed value)
80 	 * The off time of 0 is not configurable, so the mapping is:
81 	 * 0 -> off cycle = 2,
82 	 * 1 -> off cycle = 2,
83 	 * 2 -> off cycle = 3,
84 	 * 126 - > off cycle 127,
85 	 * 127 - > off cycle 1
86 	 * When on cycle == off cycle the PWM will be always on
87 	 */
88 	if (duty_cycle == 1)
89 		duty_cycle = 2;
90 	else if (duty_cycle > TWL_PWM_MAX)
91 		duty_cycle = 1;
92 
93 	base = pwm->hwpwm * 3;
94 
95 	pwm_config[1] = duty_cycle;
96 
97 	ret = twl_i2c_write(TWL_MODULE_PWM, pwm_config, base, 2);
98 	if (ret < 0)
99 		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
100 
101 	return ret;
102 }
103 
104 static int twl4030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
105 {
106 	struct twl_pwm_chip *twl = to_twl(chip);
107 	int ret;
108 	u8 val;
109 
110 	mutex_lock(&twl->mutex);
111 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
112 	if (ret < 0) {
113 		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
114 		goto out;
115 	}
116 
117 	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
118 
119 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
120 	if (ret < 0)
121 		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
122 
123 	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
124 
125 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
126 	if (ret < 0)
127 		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
128 
129 out:
130 	mutex_unlock(&twl->mutex);
131 	return ret;
132 }
133 
134 static void twl4030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
135 {
136 	struct twl_pwm_chip *twl = to_twl(chip);
137 	int ret;
138 	u8 val;
139 
140 	mutex_lock(&twl->mutex);
141 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
142 	if (ret < 0) {
143 		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
144 		goto out;
145 	}
146 
147 	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
148 
149 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
150 	if (ret < 0)
151 		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
152 
153 	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
154 
155 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
156 	if (ret < 0)
157 		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
158 
159 out:
160 	mutex_unlock(&twl->mutex);
161 }
162 
163 static int twl4030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
164 {
165 	struct twl_pwm_chip *twl = to_twl(chip);
166 	int ret;
167 	u8 val, mask, bits;
168 
169 	if (pwm->hwpwm == 1) {
170 		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
171 		bits = TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1;
172 	} else {
173 		mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
174 		bits = TWL4030_GPIO6_PWM0_MUTE_PWM0;
175 	}
176 
177 	mutex_lock(&twl->mutex);
178 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
179 	if (ret < 0) {
180 		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
181 		goto out;
182 	}
183 
184 	/* Save the current MUX configuration for the PWM */
185 	twl->twl4030_pwm_mux &= ~mask;
186 	twl->twl4030_pwm_mux |= (val & mask);
187 
188 	/* Select PWM functionality */
189 	val &= ~mask;
190 	val |= bits;
191 
192 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
193 	if (ret < 0)
194 		dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
195 
196 out:
197 	mutex_unlock(&twl->mutex);
198 	return ret;
199 }
200 
201 static void twl4030_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
202 {
203 	struct twl_pwm_chip *twl = to_twl(chip);
204 	int ret;
205 	u8 val, mask;
206 
207 	if (pwm->hwpwm == 1)
208 		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
209 	else
210 		mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
211 
212 	mutex_lock(&twl->mutex);
213 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
214 	if (ret < 0) {
215 		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
216 		goto out;
217 	}
218 
219 	/* Restore the MUX configuration for the PWM */
220 	val &= ~mask;
221 	val |= (twl->twl4030_pwm_mux & mask);
222 
223 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
224 	if (ret < 0)
225 		dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
226 
227 out:
228 	mutex_unlock(&twl->mutex);
229 }
230 
231 static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
232 {
233 	struct twl_pwm_chip *twl = to_twl(chip);
234 	int ret;
235 	u8 val;
236 
237 	mutex_lock(&twl->mutex);
238 	val = twl->twl6030_toggle3;
239 	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
240 	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
241 
242 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
243 	if (ret < 0) {
244 		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
245 		goto out;
246 	}
247 
248 	twl->twl6030_toggle3 = val;
249 out:
250 	mutex_unlock(&twl->mutex);
251 	return ret;
252 }
253 
254 static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
255 {
256 	struct twl_pwm_chip *twl = to_twl(chip);
257 	int ret;
258 	u8 val;
259 
260 	mutex_lock(&twl->mutex);
261 	val = twl->twl6030_toggle3;
262 	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
263 	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
264 
265 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
266 	if (ret < 0) {
267 		dev_err(chip->dev, "%s: Failed to read TOGGLE3\n", pwm->label);
268 		goto out;
269 	}
270 
271 	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
272 
273 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
274 	if (ret < 0) {
275 		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
276 		goto out;
277 	}
278 
279 	twl->twl6030_toggle3 = val;
280 out:
281 	mutex_unlock(&twl->mutex);
282 }
283 
284 static const struct pwm_ops twl4030_pwm_ops = {
285 	.config = twl_pwm_config,
286 	.enable = twl4030_pwm_enable,
287 	.disable = twl4030_pwm_disable,
288 	.request = twl4030_pwm_request,
289 	.free = twl4030_pwm_free,
290 	.owner = THIS_MODULE,
291 };
292 
293 static const struct pwm_ops twl6030_pwm_ops = {
294 	.config = twl_pwm_config,
295 	.enable = twl6030_pwm_enable,
296 	.disable = twl6030_pwm_disable,
297 	.owner = THIS_MODULE,
298 };
299 
300 static int twl_pwm_probe(struct platform_device *pdev)
301 {
302 	struct twl_pwm_chip *twl;
303 	int ret;
304 
305 	twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
306 	if (!twl)
307 		return -ENOMEM;
308 
309 	if (twl_class_is_4030())
310 		twl->chip.ops = &twl4030_pwm_ops;
311 	else
312 		twl->chip.ops = &twl6030_pwm_ops;
313 
314 	twl->chip.dev = &pdev->dev;
315 	twl->chip.base = -1;
316 	twl->chip.npwm = 2;
317 	twl->chip.can_sleep = true;
318 
319 	mutex_init(&twl->mutex);
320 
321 	ret = pwmchip_add(&twl->chip);
322 	if (ret < 0)
323 		return ret;
324 
325 	platform_set_drvdata(pdev, twl);
326 
327 	return 0;
328 }
329 
330 static int twl_pwm_remove(struct platform_device *pdev)
331 {
332 	struct twl_pwm_chip *twl = platform_get_drvdata(pdev);
333 
334 	return pwmchip_remove(&twl->chip);
335 }
336 
337 #ifdef CONFIG_OF
338 static const struct of_device_id twl_pwm_of_match[] = {
339 	{ .compatible = "ti,twl4030-pwm" },
340 	{ .compatible = "ti,twl6030-pwm" },
341 	{ },
342 };
343 MODULE_DEVICE_TABLE(of, twl_pwm_of_match);
344 #endif
345 
346 static struct platform_driver twl_pwm_driver = {
347 	.driver = {
348 		.name = "twl-pwm",
349 		.of_match_table = of_match_ptr(twl_pwm_of_match),
350 	},
351 	.probe = twl_pwm_probe,
352 	.remove = twl_pwm_remove,
353 };
354 module_platform_driver(twl_pwm_driver);
355 
356 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
357 MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030");
358 MODULE_ALIAS("platform:twl-pwm");
359 MODULE_LICENSE("GPL");
360