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1/*
2 * Copyright (C) 2014 Free Electrons
3 * Copyright (C) 2014 Atmel
4 *
5 * Author: Boris BREZILLON <boris.brezillon@free-electrons.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/clk.h>
21#include <linux/delay.h>
22#include <linux/mfd/atmel-hlcdc.h>
23#include <linux/module.h>
24#include <linux/platform_device.h>
25#include <linux/pwm.h>
26#include <linux/regmap.h>
27
28#define ATMEL_HLCDC_PWMCVAL_MASK GENMASK(15, 8)
29#define ATMEL_HLCDC_PWMCVAL(x) (((x) << 8) & ATMEL_HLCDC_PWMCVAL_MASK)
30#define ATMEL_HLCDC_PWMPOL BIT(4)
31#define ATMEL_HLCDC_PWMPS_MASK GENMASK(2, 0)
32#define ATMEL_HLCDC_PWMPS_MAX 0x6
33#define ATMEL_HLCDC_PWMPS(x) ((x) & ATMEL_HLCDC_PWMPS_MASK)
34
35struct atmel_hlcdc_pwm_errata {
36 bool slow_clk_erratum;
37 bool div1_clk_erratum;
38};
39
40struct atmel_hlcdc_pwm {
41 struct pwm_chip chip;
42 struct atmel_hlcdc *hlcdc;
43 struct clk *cur_clk;
44 const struct atmel_hlcdc_pwm_errata *errata;
45};
46
47static inline struct atmel_hlcdc_pwm *to_atmel_hlcdc_pwm(struct pwm_chip *chip)
48{
49 return container_of(chip, struct atmel_hlcdc_pwm, chip);
50}
51
52static int atmel_hlcdc_pwm_apply(struct pwm_chip *c, struct pwm_device *pwm,
53 struct pwm_state *state)
54{
55 struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
56 struct atmel_hlcdc *hlcdc = chip->hlcdc;
57 unsigned int status;
58 int ret;
59
60 if (state->enabled) {
61 struct clk *new_clk = hlcdc->slow_clk;
62 u64 pwmcval = state->duty_cycle * 256;
63 unsigned long clk_freq;
64 u64 clk_period_ns;
65 u32 pwmcfg;
66 int pres;
67
68 if (!chip->errata || !chip->errata->slow_clk_erratum) {
69 clk_freq = clk_get_rate(new_clk);
70 if (!clk_freq)
71 return -EINVAL;
72
73 clk_period_ns = (u64)NSEC_PER_SEC * 256;
74 do_div(clk_period_ns, clk_freq);
75 }
76
77 /* Errata: cannot use slow clk on some IP revisions */
78 if ((chip->errata && chip->errata->slow_clk_erratum) ||
79 clk_period_ns > state->period) {
80 new_clk = hlcdc->sys_clk;
81 clk_freq = clk_get_rate(new_clk);
82 if (!clk_freq)
83 return -EINVAL;
84
85 clk_period_ns = (u64)NSEC_PER_SEC * 256;
86 do_div(clk_period_ns, clk_freq);
87 }
88
89 for (pres = 0; pres <= ATMEL_HLCDC_PWMPS_MAX; pres++) {
90 /* Errata: cannot divide by 1 on some IP revisions */
91 if (!pres && chip->errata &&
92 chip->errata->div1_clk_erratum)
93 continue;
94
95 if ((clk_period_ns << pres) >= state->period)
96 break;
97 }
98
99 if (pres > ATMEL_HLCDC_PWMPS_MAX)
100 return -EINVAL;
101
102 pwmcfg = ATMEL_HLCDC_PWMPS(pres);
103
104 if (new_clk != chip->cur_clk) {
105 u32 gencfg = 0;
106 int ret;
107
108 ret = clk_prepare_enable(new_clk);
109 if (ret)
110 return ret;
111
112 clk_disable_unprepare(chip->cur_clk);
113 chip->cur_clk = new_clk;
114
115 if (new_clk == hlcdc->sys_clk)
116 gencfg = ATMEL_HLCDC_CLKPWMSEL;
117
118 ret = regmap_update_bits(hlcdc->regmap,
119 ATMEL_HLCDC_CFG(0),
120 ATMEL_HLCDC_CLKPWMSEL,
121 gencfg);
122 if (ret)
123 return ret;
124 }
125
126 do_div(pwmcval, state->period);
127
128 /*
129 * The PWM duty cycle is configurable from 0/256 to 255/256 of
130 * the period cycle. Hence we can't set a duty cycle occupying
131 * the whole period cycle if we're asked to.
132 * Set it to 255 if pwmcval is greater than 256.
133 */
134 if (pwmcval > 255)
135 pwmcval = 255;
136
137 pwmcfg |= ATMEL_HLCDC_PWMCVAL(pwmcval);
138
139 if (state->polarity == PWM_POLARITY_NORMAL)
140 pwmcfg |= ATMEL_HLCDC_PWMPOL;
141
142 ret = regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
143 ATMEL_HLCDC_PWMCVAL_MASK |
144 ATMEL_HLCDC_PWMPS_MASK |
145 ATMEL_HLCDC_PWMPOL,
146 pwmcfg);
147 if (ret)
148 return ret;
149
150 ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_EN,
151 ATMEL_HLCDC_PWM);
152 if (ret)
153 return ret;
154
155 ret = regmap_read_poll_timeout(hlcdc->regmap, ATMEL_HLCDC_SR,
156 status,
157 status & ATMEL_HLCDC_PWM,
158 10, 0);
159 if (ret)
160 return ret;
161 } else {
162 ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_DIS,
163 ATMEL_HLCDC_PWM);
164 if (ret)
165 return ret;
166
167 ret = regmap_read_poll_timeout(hlcdc->regmap, ATMEL_HLCDC_SR,
168 status,
169 !(status & ATMEL_HLCDC_PWM),
170 10, 0);
171 if (ret)
172 return ret;
173
174 clk_disable_unprepare(chip->cur_clk);
175 chip->cur_clk = NULL;
176 }
177
178 return 0;
179}
180
181static const struct pwm_ops atmel_hlcdc_pwm_ops = {
182 .apply = atmel_hlcdc_pwm_apply,
183 .owner = THIS_MODULE,
184};
185
186static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_at91sam9x5_errata = {
187 .slow_clk_erratum = true,
188};
189
190static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_sama5d3_errata = {
191 .div1_clk_erratum = true,
192};
193
194#ifdef CONFIG_PM_SLEEP
195static int atmel_hlcdc_pwm_suspend(struct device *dev)
196{
197 struct atmel_hlcdc_pwm *chip = dev_get_drvdata(dev);
198
199 /* Keep the periph clock enabled if the PWM is still running. */
200 if (pwm_is_enabled(&chip->chip.pwms[0]))
201 clk_disable_unprepare(chip->hlcdc->periph_clk);
202
203 return 0;
204}
205
206static int atmel_hlcdc_pwm_resume(struct device *dev)
207{
208 struct atmel_hlcdc_pwm *chip = dev_get_drvdata(dev);
209 struct pwm_state state;
210 int ret;
211
212 pwm_get_state(&chip->chip.pwms[0], &state);
213
214 /* Re-enable the periph clock it was stopped during suspend. */
215 if (!state.enabled) {
216 ret = clk_prepare_enable(chip->hlcdc->periph_clk);
217 if (ret)
218 return ret;
219 }
220
221 return atmel_hlcdc_pwm_apply(&chip->chip, &chip->chip.pwms[0], &state);
222}
223#endif
224
225static SIMPLE_DEV_PM_OPS(atmel_hlcdc_pwm_pm_ops,
226 atmel_hlcdc_pwm_suspend, atmel_hlcdc_pwm_resume);
227
228static const struct of_device_id atmel_hlcdc_dt_ids[] = {
229 {
230 .compatible = "atmel,at91sam9n12-hlcdc",
231 /* 9n12 has same errata as 9x5 HLCDC PWM */
232 .data = &atmel_hlcdc_pwm_at91sam9x5_errata,
233 },
234 {
235 .compatible = "atmel,at91sam9x5-hlcdc",
236 .data = &atmel_hlcdc_pwm_at91sam9x5_errata,
237 },
238 {
239 .compatible = "atmel,sama5d2-hlcdc",
240 },
241 {
242 .compatible = "atmel,sama5d3-hlcdc",
243 .data = &atmel_hlcdc_pwm_sama5d3_errata,
244 },
245 {
246 .compatible = "atmel,sama5d4-hlcdc",
247 .data = &atmel_hlcdc_pwm_sama5d3_errata,
248 },
249 { /* sentinel */ },
250};
251MODULE_DEVICE_TABLE(of, atmel_hlcdc_dt_ids);
252
253static int atmel_hlcdc_pwm_probe(struct platform_device *pdev)
254{
255 const struct of_device_id *match;
256 struct device *dev = &pdev->dev;
257 struct atmel_hlcdc_pwm *chip;
258 struct atmel_hlcdc *hlcdc;
259 int ret;
260
261 hlcdc = dev_get_drvdata(dev->parent);
262
263 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
264 if (!chip)
265 return -ENOMEM;
266
267 ret = clk_prepare_enable(hlcdc->periph_clk);
268 if (ret)
269 return ret;
270
271 match = of_match_node(atmel_hlcdc_dt_ids, dev->parent->of_node);
272 if (match)
273 chip->errata = match->data;
274
275 chip->hlcdc = hlcdc;
276 chip->chip.ops = &atmel_hlcdc_pwm_ops;
277 chip->chip.dev = dev;
278 chip->chip.base = -1;
279 chip->chip.npwm = 1;
280 chip->chip.of_xlate = of_pwm_xlate_with_flags;
281 chip->chip.of_pwm_n_cells = 3;
282
283 ret = pwmchip_add_with_polarity(&chip->chip, PWM_POLARITY_INVERSED);
284 if (ret) {
285 clk_disable_unprepare(hlcdc->periph_clk);
286 return ret;
287 }
288
289 platform_set_drvdata(pdev, chip);
290
291 return 0;
292}
293
294static int atmel_hlcdc_pwm_remove(struct platform_device *pdev)
295{
296 struct atmel_hlcdc_pwm *chip = platform_get_drvdata(pdev);
297 int ret;
298
299 ret = pwmchip_remove(&chip->chip);
300 if (ret)
301 return ret;
302
303 clk_disable_unprepare(chip->hlcdc->periph_clk);
304
305 return 0;
306}
307
308static const struct of_device_id atmel_hlcdc_pwm_dt_ids[] = {
309 { .compatible = "atmel,hlcdc-pwm" },
310 { /* sentinel */ },
311};
312
313static struct platform_driver atmel_hlcdc_pwm_driver = {
314 .driver = {
315 .name = "atmel-hlcdc-pwm",
316 .of_match_table = atmel_hlcdc_pwm_dt_ids,
317 .pm = &atmel_hlcdc_pwm_pm_ops,
318 },
319 .probe = atmel_hlcdc_pwm_probe,
320 .remove = atmel_hlcdc_pwm_remove,
321};
322module_platform_driver(atmel_hlcdc_pwm_driver);
323
324MODULE_ALIAS("platform:atmel-hlcdc-pwm");
325MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
326MODULE_DESCRIPTION("Atmel HLCDC PWM driver");
327MODULE_LICENSE("GPL v2");
1/*
2 * Copyright (C) 2014 Free Electrons
3 * Copyright (C) 2014 Atmel
4 *
5 * Author: Boris BREZILLON <boris.brezillon@free-electrons.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/clk.h>
21#include <linux/delay.h>
22#include <linux/mfd/atmel-hlcdc.h>
23#include <linux/module.h>
24#include <linux/platform_device.h>
25#include <linux/pwm.h>
26#include <linux/regmap.h>
27
28#define ATMEL_HLCDC_PWMCVAL_MASK GENMASK(15, 8)
29#define ATMEL_HLCDC_PWMCVAL(x) (((x) << 8) & ATMEL_HLCDC_PWMCVAL_MASK)
30#define ATMEL_HLCDC_PWMPOL BIT(4)
31#define ATMEL_HLCDC_PWMPS_MASK GENMASK(2, 0)
32#define ATMEL_HLCDC_PWMPS_MAX 0x6
33#define ATMEL_HLCDC_PWMPS(x) ((x) & ATMEL_HLCDC_PWMPS_MASK)
34
35struct atmel_hlcdc_pwm_errata {
36 bool slow_clk_erratum;
37 bool div1_clk_erratum;
38};
39
40struct atmel_hlcdc_pwm {
41 struct pwm_chip chip;
42 struct atmel_hlcdc *hlcdc;
43 struct clk *cur_clk;
44 const struct atmel_hlcdc_pwm_errata *errata;
45};
46
47static inline struct atmel_hlcdc_pwm *to_atmel_hlcdc_pwm(struct pwm_chip *chip)
48{
49 return container_of(chip, struct atmel_hlcdc_pwm, chip);
50}
51
52static int atmel_hlcdc_pwm_config(struct pwm_chip *c,
53 struct pwm_device *pwm,
54 int duty_ns, int period_ns)
55{
56 struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
57 struct atmel_hlcdc *hlcdc = chip->hlcdc;
58 struct clk *new_clk = hlcdc->slow_clk;
59 u64 pwmcval = duty_ns * 256;
60 unsigned long clk_freq;
61 u64 clk_period_ns;
62 u32 pwmcfg;
63 int pres;
64
65 if (!chip->errata || !chip->errata->slow_clk_erratum) {
66 clk_freq = clk_get_rate(new_clk);
67 if (!clk_freq)
68 return -EINVAL;
69
70 clk_period_ns = (u64)NSEC_PER_SEC * 256;
71 do_div(clk_period_ns, clk_freq);
72 }
73
74 /* Errata: cannot use slow clk on some IP revisions */
75 if ((chip->errata && chip->errata->slow_clk_erratum) ||
76 clk_period_ns > period_ns) {
77 new_clk = hlcdc->sys_clk;
78 clk_freq = clk_get_rate(new_clk);
79 if (!clk_freq)
80 return -EINVAL;
81
82 clk_period_ns = (u64)NSEC_PER_SEC * 256;
83 do_div(clk_period_ns, clk_freq);
84 }
85
86 for (pres = 0; pres <= ATMEL_HLCDC_PWMPS_MAX; pres++) {
87 /* Errata: cannot divide by 1 on some IP revisions */
88 if (!pres && chip->errata && chip->errata->div1_clk_erratum)
89 continue;
90
91 if ((clk_period_ns << pres) >= period_ns)
92 break;
93 }
94
95 if (pres > ATMEL_HLCDC_PWMPS_MAX)
96 return -EINVAL;
97
98 pwmcfg = ATMEL_HLCDC_PWMPS(pres);
99
100 if (new_clk != chip->cur_clk) {
101 u32 gencfg = 0;
102 int ret;
103
104 ret = clk_prepare_enable(new_clk);
105 if (ret)
106 return ret;
107
108 clk_disable_unprepare(chip->cur_clk);
109 chip->cur_clk = new_clk;
110
111 if (new_clk == hlcdc->sys_clk)
112 gencfg = ATMEL_HLCDC_CLKPWMSEL;
113
114 ret = regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(0),
115 ATMEL_HLCDC_CLKPWMSEL, gencfg);
116 if (ret)
117 return ret;
118 }
119
120 do_div(pwmcval, period_ns);
121
122 /*
123 * The PWM duty cycle is configurable from 0/256 to 255/256 of the
124 * period cycle. Hence we can't set a duty cycle occupying the
125 * whole period cycle if we're asked to.
126 * Set it to 255 if pwmcval is greater than 256.
127 */
128 if (pwmcval > 255)
129 pwmcval = 255;
130
131 pwmcfg |= ATMEL_HLCDC_PWMCVAL(pwmcval);
132
133 return regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
134 ATMEL_HLCDC_PWMCVAL_MASK |
135 ATMEL_HLCDC_PWMPS_MASK,
136 pwmcfg);
137}
138
139static int atmel_hlcdc_pwm_set_polarity(struct pwm_chip *c,
140 struct pwm_device *pwm,
141 enum pwm_polarity polarity)
142{
143 struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
144 struct atmel_hlcdc *hlcdc = chip->hlcdc;
145 u32 cfg = 0;
146
147 if (polarity == PWM_POLARITY_NORMAL)
148 cfg = ATMEL_HLCDC_PWMPOL;
149
150 return regmap_update_bits(hlcdc->regmap, ATMEL_HLCDC_CFG(6),
151 ATMEL_HLCDC_PWMPOL, cfg);
152}
153
154static int atmel_hlcdc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm)
155{
156 struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
157 struct atmel_hlcdc *hlcdc = chip->hlcdc;
158 u32 status;
159 int ret;
160
161 ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_EN, ATMEL_HLCDC_PWM);
162 if (ret)
163 return ret;
164
165 while (true) {
166 ret = regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status);
167 if (ret)
168 return ret;
169
170 if ((status & ATMEL_HLCDC_PWM) != 0)
171 break;
172
173 usleep_range(1, 10);
174 }
175
176 return 0;
177}
178
179static void atmel_hlcdc_pwm_disable(struct pwm_chip *c,
180 struct pwm_device *pwm)
181{
182 struct atmel_hlcdc_pwm *chip = to_atmel_hlcdc_pwm(c);
183 struct atmel_hlcdc *hlcdc = chip->hlcdc;
184 u32 status;
185 int ret;
186
187 ret = regmap_write(hlcdc->regmap, ATMEL_HLCDC_DIS, ATMEL_HLCDC_PWM);
188 if (ret)
189 return;
190
191 while (true) {
192 ret = regmap_read(hlcdc->regmap, ATMEL_HLCDC_SR, &status);
193 if (ret)
194 return;
195
196 if ((status & ATMEL_HLCDC_PWM) == 0)
197 break;
198
199 usleep_range(1, 10);
200 }
201}
202
203static const struct pwm_ops atmel_hlcdc_pwm_ops = {
204 .config = atmel_hlcdc_pwm_config,
205 .set_polarity = atmel_hlcdc_pwm_set_polarity,
206 .enable = atmel_hlcdc_pwm_enable,
207 .disable = atmel_hlcdc_pwm_disable,
208 .owner = THIS_MODULE,
209};
210
211static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_at91sam9x5_errata = {
212 .slow_clk_erratum = true,
213};
214
215static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_sama5d3_errata = {
216 .div1_clk_erratum = true,
217};
218
219static const struct of_device_id atmel_hlcdc_dt_ids[] = {
220 {
221 .compatible = "atmel,at91sam9n12-hlcdc",
222 /* 9n12 has same errata as 9x5 HLCDC PWM */
223 .data = &atmel_hlcdc_pwm_at91sam9x5_errata,
224 },
225 {
226 .compatible = "atmel,at91sam9x5-hlcdc",
227 .data = &atmel_hlcdc_pwm_at91sam9x5_errata,
228 },
229 {
230 .compatible = "atmel,sama5d2-hlcdc",
231 },
232 {
233 .compatible = "atmel,sama5d3-hlcdc",
234 .data = &atmel_hlcdc_pwm_sama5d3_errata,
235 },
236 {
237 .compatible = "atmel,sama5d4-hlcdc",
238 .data = &atmel_hlcdc_pwm_sama5d3_errata,
239 },
240 { /* sentinel */ },
241};
242MODULE_DEVICE_TABLE(of, atmel_hlcdc_dt_ids);
243
244static int atmel_hlcdc_pwm_probe(struct platform_device *pdev)
245{
246 const struct of_device_id *match;
247 struct device *dev = &pdev->dev;
248 struct atmel_hlcdc_pwm *chip;
249 struct atmel_hlcdc *hlcdc;
250 int ret;
251
252 hlcdc = dev_get_drvdata(dev->parent);
253
254 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
255 if (!chip)
256 return -ENOMEM;
257
258 ret = clk_prepare_enable(hlcdc->periph_clk);
259 if (ret)
260 return ret;
261
262 match = of_match_node(atmel_hlcdc_dt_ids, dev->parent->of_node);
263 if (match)
264 chip->errata = match->data;
265
266 chip->hlcdc = hlcdc;
267 chip->chip.ops = &atmel_hlcdc_pwm_ops;
268 chip->chip.dev = dev;
269 chip->chip.base = -1;
270 chip->chip.npwm = 1;
271 chip->chip.of_xlate = of_pwm_xlate_with_flags;
272 chip->chip.of_pwm_n_cells = 3;
273 chip->chip.can_sleep = 1;
274
275 ret = pwmchip_add(&chip->chip);
276 if (ret) {
277 clk_disable_unprepare(hlcdc->periph_clk);
278 return ret;
279 }
280
281 platform_set_drvdata(pdev, chip);
282
283 return 0;
284}
285
286static int atmel_hlcdc_pwm_remove(struct platform_device *pdev)
287{
288 struct atmel_hlcdc_pwm *chip = platform_get_drvdata(pdev);
289 int ret;
290
291 ret = pwmchip_remove(&chip->chip);
292 if (ret)
293 return ret;
294
295 clk_disable_unprepare(chip->hlcdc->periph_clk);
296
297 return 0;
298}
299
300static const struct of_device_id atmel_hlcdc_pwm_dt_ids[] = {
301 { .compatible = "atmel,hlcdc-pwm" },
302 { /* sentinel */ },
303};
304
305static struct platform_driver atmel_hlcdc_pwm_driver = {
306 .driver = {
307 .name = "atmel-hlcdc-pwm",
308 .of_match_table = atmel_hlcdc_pwm_dt_ids,
309 },
310 .probe = atmel_hlcdc_pwm_probe,
311 .remove = atmel_hlcdc_pwm_remove,
312};
313module_platform_driver(atmel_hlcdc_pwm_driver);
314
315MODULE_ALIAS("platform:atmel-hlcdc-pwm");
316MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
317MODULE_DESCRIPTION("Atmel HLCDC PWM driver");
318MODULE_LICENSE("GPL v2");