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/of.h>
22 #include <linux/platform_device.h>
23 #include <linux/pwm.h>
24 #include <linux/mfd/twl.h>
25 #include <linux/slab.h>
26 
27 /*
28  * This driver handles the PWMs of TWL4030 and TWL6030.
29  * The TRM names for the PWMs on TWL4030 are: PWM0, PWM1
30  * TWL6030 also have two PWMs named in the TRM as PWM1, PWM2
31  */
32 
33 #define TWL_PWM_MAX		0x7f
34 
35 /* Registers, bits and macro for TWL4030 */
36 #define TWL4030_GPBR1_REG	0x0c
37 #define TWL4030_PMBR1_REG	0x0d
38 
39 /* GPBR1 register bits */
40 #define TWL4030_PWMXCLK_ENABLE	(1 << 0)
41 #define TWL4030_PWMX_ENABLE	(1 << 2)
42 #define TWL4030_PWMX_BITS	(TWL4030_PWMX_ENABLE | TWL4030_PWMXCLK_ENABLE)
43 #define TWL4030_PWM_TOGGLE(pwm, x)	((x) << (pwm))
44 
45 /* PMBR1 register bits */
46 #define TWL4030_GPIO6_PWM0_MUTE_MASK		(0x03 << 2)
47 #define TWL4030_GPIO6_PWM0_MUTE_PWM0		(0x01 << 2)
48 #define TWL4030_GPIO7_VIBRASYNC_PWM1_MASK	(0x03 << 4)
49 #define TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1	(0x03 << 4)
50 
51 /* Register, bits and macro for TWL6030 */
52 #define TWL6030_TOGGLE3_REG	0x92
53 
54 #define TWL6030_PWMXR		(1 << 0)
55 #define TWL6030_PWMXS		(1 << 1)
56 #define TWL6030_PWMXEN		(1 << 2)
57 #define TWL6030_PWM_TOGGLE(pwm, x)	((x) << (pwm * 3))
58 
59 struct twl_pwm_chip {
60 	struct pwm_chip chip;
61 	struct mutex mutex;
62 	u8 twl6030_toggle3;
63 	u8 twl4030_pwm_mux;
64 };
65 
to_twl(struct pwm_chip * chip)66 static inline struct twl_pwm_chip *to_twl(struct pwm_chip *chip)
67 {
68 	return container_of(chip, struct twl_pwm_chip, chip);
69 }
70 
twl_pwm_config(struct pwm_chip * chip,struct pwm_device * pwm,int duty_ns,int period_ns)71 static int twl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
72 			      int duty_ns, int period_ns)
73 {
74 	int duty_cycle = DIV_ROUND_UP(duty_ns * TWL_PWM_MAX, period_ns) + 1;
75 	u8 pwm_config[2] = { 1, 0 };
76 	int base, ret;
77 
78 	/*
79 	 * To configure the duty period:
80 	 * On-cycle is set to 1 (the minimum allowed value)
81 	 * The off time of 0 is not configurable, so the mapping is:
82 	 * 0 -> off cycle = 2,
83 	 * 1 -> off cycle = 2,
84 	 * 2 -> off cycle = 3,
85 	 * 126 - > off cycle 127,
86 	 * 127 - > off cycle 1
87 	 * When on cycle == off cycle the PWM will be always on
88 	 */
89 	if (duty_cycle == 1)
90 		duty_cycle = 2;
91 	else if (duty_cycle > TWL_PWM_MAX)
92 		duty_cycle = 1;
93 
94 	base = pwm->hwpwm * 3;
95 
96 	pwm_config[1] = duty_cycle;
97 
98 	ret = twl_i2c_write(TWL_MODULE_PWM, pwm_config, base, 2);
99 	if (ret < 0)
100 		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
101 
102 	return ret;
103 }
104 
twl4030_pwm_enable(struct pwm_chip * chip,struct pwm_device * pwm)105 static int twl4030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
106 {
107 	struct twl_pwm_chip *twl = to_twl(chip);
108 	int ret;
109 	u8 val;
110 
111 	mutex_lock(&twl->mutex);
112 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
113 	if (ret < 0) {
114 		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
115 		goto out;
116 	}
117 
118 	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
119 
120 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
121 	if (ret < 0)
122 		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
123 
124 	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
125 
126 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
127 	if (ret < 0)
128 		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
129 
130 out:
131 	mutex_unlock(&twl->mutex);
132 	return ret;
133 }
134 
twl4030_pwm_disable(struct pwm_chip * chip,struct pwm_device * pwm)135 static void twl4030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
136 {
137 	struct twl_pwm_chip *twl = to_twl(chip);
138 	int ret;
139 	u8 val;
140 
141 	mutex_lock(&twl->mutex);
142 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
143 	if (ret < 0) {
144 		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
145 		goto out;
146 	}
147 
148 	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
149 
150 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
151 	if (ret < 0)
152 		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
153 
154 	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
155 
156 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
157 	if (ret < 0)
158 		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
159 
160 out:
161 	mutex_unlock(&twl->mutex);
162 }
163 
twl4030_pwm_request(struct pwm_chip * chip,struct pwm_device * pwm)164 static int twl4030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
165 {
166 	struct twl_pwm_chip *twl = to_twl(chip);
167 	int ret;
168 	u8 val, mask, bits;
169 
170 	if (pwm->hwpwm == 1) {
171 		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
172 		bits = TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1;
173 	} else {
174 		mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
175 		bits = TWL4030_GPIO6_PWM0_MUTE_PWM0;
176 	}
177 
178 	mutex_lock(&twl->mutex);
179 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
180 	if (ret < 0) {
181 		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
182 		goto out;
183 	}
184 
185 	/* Save the current MUX configuration for the PWM */
186 	twl->twl4030_pwm_mux &= ~mask;
187 	twl->twl4030_pwm_mux |= (val & mask);
188 
189 	/* Select PWM functionality */
190 	val &= ~mask;
191 	val |= bits;
192 
193 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
194 	if (ret < 0)
195 		dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
196 
197 out:
198 	mutex_unlock(&twl->mutex);
199 	return ret;
200 }
201 
twl4030_pwm_free(struct pwm_chip * chip,struct pwm_device * pwm)202 static void twl4030_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
203 {
204 	struct twl_pwm_chip *twl = to_twl(chip);
205 	int ret;
206 	u8 val, mask;
207 
208 	if (pwm->hwpwm == 1)
209 		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
210 	else
211 		mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
212 
213 	mutex_lock(&twl->mutex);
214 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
215 	if (ret < 0) {
216 		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
217 		goto out;
218 	}
219 
220 	/* Restore the MUX configuration for the PWM */
221 	val &= ~mask;
222 	val |= (twl->twl4030_pwm_mux & mask);
223 
224 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
225 	if (ret < 0)
226 		dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
227 
228 out:
229 	mutex_unlock(&twl->mutex);
230 }
231 
twl6030_pwm_enable(struct pwm_chip * chip,struct pwm_device * pwm)232 static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
233 {
234 	struct twl_pwm_chip *twl = to_twl(chip);
235 	int ret;
236 	u8 val;
237 
238 	mutex_lock(&twl->mutex);
239 	val = twl->twl6030_toggle3;
240 	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
241 	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
242 
243 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
244 	if (ret < 0) {
245 		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
246 		goto out;
247 	}
248 
249 	twl->twl6030_toggle3 = val;
250 out:
251 	mutex_unlock(&twl->mutex);
252 	return ret;
253 }
254 
twl6030_pwm_disable(struct pwm_chip * chip,struct pwm_device * pwm)255 static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
256 {
257 	struct twl_pwm_chip *twl = to_twl(chip);
258 	int ret;
259 	u8 val;
260 
261 	mutex_lock(&twl->mutex);
262 	val = twl->twl6030_toggle3;
263 	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
264 	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
265 
266 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
267 	if (ret < 0) {
268 		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
269 		goto out;
270 	}
271 
272 	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXEN);
273 
274 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
275 	if (ret < 0) {
276 		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
277 		goto out;
278 	}
279 
280 	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXEN);
281 
282 	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
283 	if (ret < 0) {
284 		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
285 		goto out;
286 	}
287 
288 	twl->twl6030_toggle3 = val;
289 out:
290 	mutex_unlock(&twl->mutex);
291 }
292 
293 static const struct pwm_ops twl4030_pwm_ops = {
294 	.config = twl_pwm_config,
295 	.enable = twl4030_pwm_enable,
296 	.disable = twl4030_pwm_disable,
297 	.request = twl4030_pwm_request,
298 	.free = twl4030_pwm_free,
299 	.owner = THIS_MODULE,
300 };
301 
302 static const struct pwm_ops twl6030_pwm_ops = {
303 	.config = twl_pwm_config,
304 	.enable = twl6030_pwm_enable,
305 	.disable = twl6030_pwm_disable,
306 	.owner = THIS_MODULE,
307 };
308 
twl_pwm_probe(struct platform_device * pdev)309 static int twl_pwm_probe(struct platform_device *pdev)
310 {
311 	struct twl_pwm_chip *twl;
312 	int ret;
313 
314 	twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
315 	if (!twl)
316 		return -ENOMEM;
317 
318 	if (twl_class_is_4030())
319 		twl->chip.ops = &twl4030_pwm_ops;
320 	else
321 		twl->chip.ops = &twl6030_pwm_ops;
322 
323 	twl->chip.dev = &pdev->dev;
324 	twl->chip.base = -1;
325 	twl->chip.npwm = 2;
326 
327 	mutex_init(&twl->mutex);
328 
329 	ret = pwmchip_add(&twl->chip);
330 	if (ret < 0)
331 		return ret;
332 
333 	platform_set_drvdata(pdev, twl);
334 
335 	return 0;
336 }
337 
twl_pwm_remove(struct platform_device * pdev)338 static int twl_pwm_remove(struct platform_device *pdev)
339 {
340 	struct twl_pwm_chip *twl = platform_get_drvdata(pdev);
341 
342 	return pwmchip_remove(&twl->chip);
343 }
344 
345 #ifdef CONFIG_OF
346 static const struct of_device_id twl_pwm_of_match[] = {
347 	{ .compatible = "ti,twl4030-pwm" },
348 	{ .compatible = "ti,twl6030-pwm" },
349 	{ },
350 };
351 MODULE_DEVICE_TABLE(of, twl_pwm_of_match);
352 #endif
353 
354 static struct platform_driver twl_pwm_driver = {
355 	.driver = {
356 		.name = "twl-pwm",
357 		.of_match_table = of_match_ptr(twl_pwm_of_match),
358 	},
359 	.probe = twl_pwm_probe,
360 	.remove = twl_pwm_remove,
361 };
362 module_platform_driver(twl_pwm_driver);
363 
364 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
365 MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030");
366 MODULE_ALIAS("platform:twl-pwm");
367 MODULE_LICENSE("GPL");
368