1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * MediaTek Pulse Width Modulator driver
4 *
5 * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
6 * Copyright (C) 2017 Zhi Mao <zhi.mao@mediatek.com>
7 *
8 */
9
10 #include <linux/err.h>
11 #include <linux/io.h>
12 #include <linux/ioport.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/clk.h>
16 #include <linux/of.h>
17 #include <linux/platform_device.h>
18 #include <linux/pwm.h>
19 #include <linux/slab.h>
20 #include <linux/types.h>
21
22 /* PWM registers and bits definitions */
23 #define PWMCON 0x00
24 #define PWMHDUR 0x04
25 #define PWMLDUR 0x08
26 #define PWMGDUR 0x0c
27 #define PWMWAVENUM 0x28
28 #define PWMDWIDTH 0x2c
29 #define PWM45DWIDTH_FIXUP 0x30
30 #define PWMTHRES 0x30
31 #define PWM45THRES_FIXUP 0x34
32 #define PWM_CK_26M_SEL 0x210
33
34 #define PWM_CLK_DIV_MAX 7
35
36 struct pwm_mediatek_of_data {
37 unsigned int num_pwms;
38 bool pwm45_fixup;
39 bool has_ck_26m_sel;
40 const unsigned int *reg_offset;
41 };
42
43 /**
44 * struct pwm_mediatek_chip - struct representing PWM chip
45 * @regs: base address of PWM chip
46 * @clk_top: the top clock generator
47 * @clk_main: the clock used by PWM core
48 * @clk_pwms: the clock used by each PWM channel
49 * @soc: pointer to chip's platform data
50 */
51 struct pwm_mediatek_chip {
52 void __iomem *regs;
53 struct clk *clk_top;
54 struct clk *clk_main;
55 struct clk **clk_pwms;
56 const struct pwm_mediatek_of_data *soc;
57 };
58
59 static const unsigned int mtk_pwm_reg_offset_v1[] = {
60 0x0010, 0x0050, 0x0090, 0x00d0, 0x0110, 0x0150, 0x0190, 0x0220
61 };
62
63 static const unsigned int mtk_pwm_reg_offset_v2[] = {
64 0x0080, 0x00c0, 0x0100, 0x0140, 0x0180, 0x01c0, 0x0200, 0x0240
65 };
66
67 static inline struct pwm_mediatek_chip *
to_pwm_mediatek_chip(struct pwm_chip * chip)68 to_pwm_mediatek_chip(struct pwm_chip *chip)
69 {
70 return pwmchip_get_drvdata(chip);
71 }
72
pwm_mediatek_clk_enable(struct pwm_chip * chip,struct pwm_device * pwm)73 static int pwm_mediatek_clk_enable(struct pwm_chip *chip,
74 struct pwm_device *pwm)
75 {
76 struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
77 int ret;
78
79 ret = clk_prepare_enable(pc->clk_top);
80 if (ret < 0)
81 return ret;
82
83 ret = clk_prepare_enable(pc->clk_main);
84 if (ret < 0)
85 goto disable_clk_top;
86
87 ret = clk_prepare_enable(pc->clk_pwms[pwm->hwpwm]);
88 if (ret < 0)
89 goto disable_clk_main;
90
91 return 0;
92
93 disable_clk_main:
94 clk_disable_unprepare(pc->clk_main);
95 disable_clk_top:
96 clk_disable_unprepare(pc->clk_top);
97
98 return ret;
99 }
100
pwm_mediatek_clk_disable(struct pwm_chip * chip,struct pwm_device * pwm)101 static void pwm_mediatek_clk_disable(struct pwm_chip *chip,
102 struct pwm_device *pwm)
103 {
104 struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
105
106 clk_disable_unprepare(pc->clk_pwms[pwm->hwpwm]);
107 clk_disable_unprepare(pc->clk_main);
108 clk_disable_unprepare(pc->clk_top);
109 }
110
pwm_mediatek_writel(struct pwm_mediatek_chip * chip,unsigned int num,unsigned int offset,u32 value)111 static inline void pwm_mediatek_writel(struct pwm_mediatek_chip *chip,
112 unsigned int num, unsigned int offset,
113 u32 value)
114 {
115 writel(value, chip->regs + chip->soc->reg_offset[num] + offset);
116 }
117
pwm_mediatek_config(struct pwm_chip * chip,struct pwm_device * pwm,int duty_ns,int period_ns)118 static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
119 int duty_ns, int period_ns)
120 {
121 struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
122 u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH,
123 reg_thres = PWMTHRES;
124 u64 resolution;
125 int ret;
126
127 ret = pwm_mediatek_clk_enable(chip, pwm);
128
129 if (ret < 0)
130 return ret;
131
132 /* Make sure we use the bus clock and not the 26MHz clock */
133 if (pc->soc->has_ck_26m_sel)
134 writel(0, pc->regs + PWM_CK_26M_SEL);
135
136 /* Using resolution in picosecond gets accuracy higher */
137 resolution = (u64)NSEC_PER_SEC * 1000;
138 do_div(resolution, clk_get_rate(pc->clk_pwms[pwm->hwpwm]));
139
140 cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution);
141 while (cnt_period > 8191) {
142 resolution *= 2;
143 clkdiv++;
144 cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000,
145 resolution);
146 }
147
148 if (clkdiv > PWM_CLK_DIV_MAX) {
149 pwm_mediatek_clk_disable(chip, pwm);
150 dev_err(pwmchip_parent(chip), "period of %d ns not supported\n", period_ns);
151 return -EINVAL;
152 }
153
154 if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) {
155 /*
156 * PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES
157 * from the other PWMs on MT7623.
158 */
159 reg_width = PWM45DWIDTH_FIXUP;
160 reg_thres = PWM45THRES_FIXUP;
161 }
162
163 cnt_duty = DIV_ROUND_CLOSEST_ULL((u64)duty_ns * 1000, resolution);
164 pwm_mediatek_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv);
165 pwm_mediatek_writel(pc, pwm->hwpwm, reg_width, cnt_period);
166 pwm_mediatek_writel(pc, pwm->hwpwm, reg_thres, cnt_duty);
167
168 pwm_mediatek_clk_disable(chip, pwm);
169
170 return 0;
171 }
172
pwm_mediatek_enable(struct pwm_chip * chip,struct pwm_device * pwm)173 static int pwm_mediatek_enable(struct pwm_chip *chip, struct pwm_device *pwm)
174 {
175 struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
176 u32 value;
177 int ret;
178
179 ret = pwm_mediatek_clk_enable(chip, pwm);
180 if (ret < 0)
181 return ret;
182
183 value = readl(pc->regs);
184 value |= BIT(pwm->hwpwm);
185 writel(value, pc->regs);
186
187 return 0;
188 }
189
pwm_mediatek_disable(struct pwm_chip * chip,struct pwm_device * pwm)190 static void pwm_mediatek_disable(struct pwm_chip *chip, struct pwm_device *pwm)
191 {
192 struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
193 u32 value;
194
195 value = readl(pc->regs);
196 value &= ~BIT(pwm->hwpwm);
197 writel(value, pc->regs);
198
199 pwm_mediatek_clk_disable(chip, pwm);
200 }
201
pwm_mediatek_apply(struct pwm_chip * chip,struct pwm_device * pwm,const struct pwm_state * state)202 static int pwm_mediatek_apply(struct pwm_chip *chip, struct pwm_device *pwm,
203 const struct pwm_state *state)
204 {
205 int err;
206
207 if (state->polarity != PWM_POLARITY_NORMAL)
208 return -EINVAL;
209
210 if (!state->enabled) {
211 if (pwm->state.enabled)
212 pwm_mediatek_disable(chip, pwm);
213
214 return 0;
215 }
216
217 err = pwm_mediatek_config(chip, pwm, state->duty_cycle, state->period);
218 if (err)
219 return err;
220
221 if (!pwm->state.enabled)
222 err = pwm_mediatek_enable(chip, pwm);
223
224 return err;
225 }
226
227 static const struct pwm_ops pwm_mediatek_ops = {
228 .apply = pwm_mediatek_apply,
229 };
230
pwm_mediatek_probe(struct platform_device * pdev)231 static int pwm_mediatek_probe(struct platform_device *pdev)
232 {
233 struct pwm_chip *chip;
234 struct pwm_mediatek_chip *pc;
235 const struct pwm_mediatek_of_data *soc;
236 unsigned int i;
237 int ret;
238
239 soc = of_device_get_match_data(&pdev->dev);
240
241 chip = devm_pwmchip_alloc(&pdev->dev, soc->num_pwms, sizeof(*pc));
242 if (IS_ERR(chip))
243 return PTR_ERR(chip);
244 pc = to_pwm_mediatek_chip(chip);
245
246 pc->soc = soc;
247
248 pc->regs = devm_platform_ioremap_resource(pdev, 0);
249 if (IS_ERR(pc->regs))
250 return PTR_ERR(pc->regs);
251
252 pc->clk_pwms = devm_kmalloc_array(&pdev->dev, soc->num_pwms,
253 sizeof(*pc->clk_pwms), GFP_KERNEL);
254 if (!pc->clk_pwms)
255 return -ENOMEM;
256
257 pc->clk_top = devm_clk_get(&pdev->dev, "top");
258 if (IS_ERR(pc->clk_top))
259 return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_top),
260 "Failed to get top clock\n");
261
262 pc->clk_main = devm_clk_get(&pdev->dev, "main");
263 if (IS_ERR(pc->clk_main))
264 return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_main),
265 "Failed to get main clock\n");
266
267 for (i = 0; i < soc->num_pwms; i++) {
268 char name[8];
269
270 snprintf(name, sizeof(name), "pwm%d", i + 1);
271
272 pc->clk_pwms[i] = devm_clk_get(&pdev->dev, name);
273 if (IS_ERR(pc->clk_pwms[i]))
274 return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_pwms[i]),
275 "Failed to get %s clock\n", name);
276 }
277
278 chip->ops = &pwm_mediatek_ops;
279
280 ret = devm_pwmchip_add(&pdev->dev, chip);
281 if (ret < 0)
282 return dev_err_probe(&pdev->dev, ret, "pwmchip_add() failed\n");
283
284 return 0;
285 }
286
287 static const struct pwm_mediatek_of_data mt2712_pwm_data = {
288 .num_pwms = 8,
289 .pwm45_fixup = false,
290 .has_ck_26m_sel = false,
291 .reg_offset = mtk_pwm_reg_offset_v1,
292 };
293
294 static const struct pwm_mediatek_of_data mt6795_pwm_data = {
295 .num_pwms = 7,
296 .pwm45_fixup = false,
297 .has_ck_26m_sel = false,
298 .reg_offset = mtk_pwm_reg_offset_v1,
299 };
300
301 static const struct pwm_mediatek_of_data mt7622_pwm_data = {
302 .num_pwms = 6,
303 .pwm45_fixup = false,
304 .has_ck_26m_sel = true,
305 .reg_offset = mtk_pwm_reg_offset_v1,
306 };
307
308 static const struct pwm_mediatek_of_data mt7623_pwm_data = {
309 .num_pwms = 5,
310 .pwm45_fixup = true,
311 .has_ck_26m_sel = false,
312 .reg_offset = mtk_pwm_reg_offset_v1,
313 };
314
315 static const struct pwm_mediatek_of_data mt7628_pwm_data = {
316 .num_pwms = 4,
317 .pwm45_fixup = true,
318 .has_ck_26m_sel = false,
319 .reg_offset = mtk_pwm_reg_offset_v1,
320 };
321
322 static const struct pwm_mediatek_of_data mt7629_pwm_data = {
323 .num_pwms = 1,
324 .pwm45_fixup = false,
325 .has_ck_26m_sel = false,
326 .reg_offset = mtk_pwm_reg_offset_v1,
327 };
328
329 static const struct pwm_mediatek_of_data mt7981_pwm_data = {
330 .num_pwms = 3,
331 .pwm45_fixup = false,
332 .has_ck_26m_sel = true,
333 .reg_offset = mtk_pwm_reg_offset_v2,
334 };
335
336 static const struct pwm_mediatek_of_data mt7986_pwm_data = {
337 .num_pwms = 2,
338 .pwm45_fixup = false,
339 .has_ck_26m_sel = true,
340 .reg_offset = mtk_pwm_reg_offset_v1,
341 };
342
343 static const struct pwm_mediatek_of_data mt7988_pwm_data = {
344 .num_pwms = 8,
345 .pwm45_fixup = false,
346 .has_ck_26m_sel = false,
347 .reg_offset = mtk_pwm_reg_offset_v2,
348 };
349
350 static const struct pwm_mediatek_of_data mt8183_pwm_data = {
351 .num_pwms = 4,
352 .pwm45_fixup = false,
353 .has_ck_26m_sel = true,
354 .reg_offset = mtk_pwm_reg_offset_v1,
355 };
356
357 static const struct pwm_mediatek_of_data mt8365_pwm_data = {
358 .num_pwms = 3,
359 .pwm45_fixup = false,
360 .has_ck_26m_sel = true,
361 .reg_offset = mtk_pwm_reg_offset_v1,
362 };
363
364 static const struct pwm_mediatek_of_data mt8516_pwm_data = {
365 .num_pwms = 5,
366 .pwm45_fixup = false,
367 .has_ck_26m_sel = true,
368 .reg_offset = mtk_pwm_reg_offset_v1,
369 };
370
371 static const struct of_device_id pwm_mediatek_of_match[] = {
372 { .compatible = "mediatek,mt2712-pwm", .data = &mt2712_pwm_data },
373 { .compatible = "mediatek,mt6795-pwm", .data = &mt6795_pwm_data },
374 { .compatible = "mediatek,mt7622-pwm", .data = &mt7622_pwm_data },
375 { .compatible = "mediatek,mt7623-pwm", .data = &mt7623_pwm_data },
376 { .compatible = "mediatek,mt7628-pwm", .data = &mt7628_pwm_data },
377 { .compatible = "mediatek,mt7629-pwm", .data = &mt7629_pwm_data },
378 { .compatible = "mediatek,mt7981-pwm", .data = &mt7981_pwm_data },
379 { .compatible = "mediatek,mt7986-pwm", .data = &mt7986_pwm_data },
380 { .compatible = "mediatek,mt7988-pwm", .data = &mt7988_pwm_data },
381 { .compatible = "mediatek,mt8183-pwm", .data = &mt8183_pwm_data },
382 { .compatible = "mediatek,mt8365-pwm", .data = &mt8365_pwm_data },
383 { .compatible = "mediatek,mt8516-pwm", .data = &mt8516_pwm_data },
384 { },
385 };
386 MODULE_DEVICE_TABLE(of, pwm_mediatek_of_match);
387
388 static struct platform_driver pwm_mediatek_driver = {
389 .driver = {
390 .name = "pwm-mediatek",
391 .of_match_table = pwm_mediatek_of_match,
392 },
393 .probe = pwm_mediatek_probe,
394 };
395 module_platform_driver(pwm_mediatek_driver);
396
397 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
398 MODULE_DESCRIPTION("MediaTek general purpose Pulse Width Modulator driver");
399 MODULE_LICENSE("GPL v2");
400