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84a14ae8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
277bb6a2 NT |
2 | /* |
3 | * Imagination Technologies Pulse Width Modulator driver | |
4 | * | |
5 | * Copyright (c) 2014-2015, Imagination Technologies | |
6 | * | |
7 | * Based on drivers/pwm/pwm-tegra.c, Copyright (c) 2010, NVIDIA Corporation | |
277bb6a2 NT |
8 | */ |
9 | ||
10 | #include <linux/clk.h> | |
11 | #include <linux/err.h> | |
12 | #include <linux/io.h> | |
13 | #include <linux/mfd/syscon.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/of.h> | |
1e70897d | 16 | #include <linux/of_device.h> |
277bb6a2 | 17 | #include <linux/platform_device.h> |
e690ae52 | 18 | #include <linux/pm_runtime.h> |
277bb6a2 NT |
19 | #include <linux/pwm.h> |
20 | #include <linux/regmap.h> | |
21 | #include <linux/slab.h> | |
22 | ||
23 | /* PWM registers */ | |
24 | #define PWM_CTRL_CFG 0x0000 | |
25 | #define PWM_CTRL_CFG_NO_SUB_DIV 0 | |
26 | #define PWM_CTRL_CFG_SUB_DIV0 1 | |
27 | #define PWM_CTRL_CFG_SUB_DIV1 2 | |
28 | #define PWM_CTRL_CFG_SUB_DIV0_DIV1 3 | |
29 | #define PWM_CTRL_CFG_DIV_SHIFT(ch) ((ch) * 2 + 4) | |
30 | #define PWM_CTRL_CFG_DIV_MASK 0x3 | |
31 | ||
32 | #define PWM_CH_CFG(ch) (0x4 + (ch) * 4) | |
33 | #define PWM_CH_CFG_TMBASE_SHIFT 0 | |
34 | #define PWM_CH_CFG_DUTY_SHIFT 16 | |
35 | ||
36 | #define PERIP_PWM_PDM_CONTROL 0x0140 | |
37 | #define PERIP_PWM_PDM_CONTROL_CH_MASK 0x1 | |
38 | #define PERIP_PWM_PDM_CONTROL_CH_SHIFT(ch) ((ch) * 4) | |
39 | ||
e690ae52 EB |
40 | #define IMG_PWM_PM_TIMEOUT 1000 /* ms */ |
41 | ||
1e70897d NT |
42 | /* |
43 | * PWM period is specified with a timebase register, | |
44 | * in number of step periods. The PWM duty cycle is also | |
45 | * specified in step periods, in the [0, $timebase] range. | |
46 | * In other words, the timebase imposes the duty cycle | |
47 | * resolution. Therefore, let's constraint the timebase to | |
48 | * a minimum value to allow a sane range of duty cycle values. | |
49 | * Imposing a minimum timebase, will impose a maximum PWM frequency. | |
50 | * | |
51 | * The value chosen is completely arbitrary. | |
52 | */ | |
53 | #define MIN_TMBASE_STEPS 16 | |
54 | ||
a18afce5 EB |
55 | #define IMG_PWM_NPWM 4 |
56 | ||
1e70897d NT |
57 | struct img_pwm_soc_data { |
58 | u32 max_timebase; | |
59 | }; | |
277bb6a2 NT |
60 | |
61 | struct img_pwm_chip { | |
62 | struct device *dev; | |
63 | struct pwm_chip chip; | |
64 | struct clk *pwm_clk; | |
65 | struct clk *sys_clk; | |
66 | void __iomem *base; | |
67 | struct regmap *periph_regs; | |
1e70897d NT |
68 | int max_period_ns; |
69 | int min_period_ns; | |
70 | const struct img_pwm_soc_data *data; | |
a18afce5 EB |
71 | u32 suspend_ctrl_cfg; |
72 | u32 suspend_ch_cfg[IMG_PWM_NPWM]; | |
277bb6a2 NT |
73 | }; |
74 | ||
75 | static inline struct img_pwm_chip *to_img_pwm_chip(struct pwm_chip *chip) | |
76 | { | |
77 | return container_of(chip, struct img_pwm_chip, chip); | |
78 | } | |
79 | ||
22e8e19a | 80 | static inline void img_pwm_writel(struct img_pwm_chip *imgchip, |
277bb6a2 NT |
81 | u32 reg, u32 val) |
82 | { | |
22e8e19a | 83 | writel(val, imgchip->base + reg); |
277bb6a2 NT |
84 | } |
85 | ||
22e8e19a | 86 | static inline u32 img_pwm_readl(struct img_pwm_chip *imgchip, u32 reg) |
277bb6a2 | 87 | { |
22e8e19a | 88 | return readl(imgchip->base + reg); |
277bb6a2 NT |
89 | } |
90 | ||
91 | static int img_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, | |
92 | int duty_ns, int period_ns) | |
93 | { | |
94 | u32 val, div, duty, timebase; | |
95 | unsigned long mul, output_clk_hz, input_clk_hz; | |
22e8e19a UKK |
96 | struct img_pwm_chip *imgchip = to_img_pwm_chip(chip); |
97 | unsigned int max_timebase = imgchip->data->max_timebase; | |
e690ae52 | 98 | int ret; |
1e70897d | 99 | |
22e8e19a UKK |
100 | if (period_ns < imgchip->min_period_ns || |
101 | period_ns > imgchip->max_period_ns) { | |
1e70897d NT |
102 | dev_err(chip->dev, "configured period not in range\n"); |
103 | return -ERANGE; | |
104 | } | |
277bb6a2 | 105 | |
22e8e19a | 106 | input_clk_hz = clk_get_rate(imgchip->pwm_clk); |
277bb6a2 NT |
107 | output_clk_hz = DIV_ROUND_UP(NSEC_PER_SEC, period_ns); |
108 | ||
109 | mul = DIV_ROUND_UP(input_clk_hz, output_clk_hz); | |
1e70897d | 110 | if (mul <= max_timebase) { |
277bb6a2 NT |
111 | div = PWM_CTRL_CFG_NO_SUB_DIV; |
112 | timebase = DIV_ROUND_UP(mul, 1); | |
1e70897d | 113 | } else if (mul <= max_timebase * 8) { |
277bb6a2 NT |
114 | div = PWM_CTRL_CFG_SUB_DIV0; |
115 | timebase = DIV_ROUND_UP(mul, 8); | |
1e70897d | 116 | } else if (mul <= max_timebase * 64) { |
277bb6a2 NT |
117 | div = PWM_CTRL_CFG_SUB_DIV1; |
118 | timebase = DIV_ROUND_UP(mul, 64); | |
1e70897d | 119 | } else if (mul <= max_timebase * 512) { |
277bb6a2 NT |
120 | div = PWM_CTRL_CFG_SUB_DIV0_DIV1; |
121 | timebase = DIV_ROUND_UP(mul, 512); | |
44481955 | 122 | } else { |
277bb6a2 NT |
123 | dev_err(chip->dev, |
124 | "failed to configure timebase steps/divider value\n"); | |
125 | return -EINVAL; | |
126 | } | |
127 | ||
128 | duty = DIV_ROUND_UP(timebase * duty_ns, period_ns); | |
129 | ||
b6ce2af8 UKK |
130 | ret = pm_runtime_resume_and_get(chip->dev); |
131 | if (ret < 0) | |
e690ae52 EB |
132 | return ret; |
133 | ||
22e8e19a | 134 | val = img_pwm_readl(imgchip, PWM_CTRL_CFG); |
277bb6a2 NT |
135 | val &= ~(PWM_CTRL_CFG_DIV_MASK << PWM_CTRL_CFG_DIV_SHIFT(pwm->hwpwm)); |
136 | val |= (div & PWM_CTRL_CFG_DIV_MASK) << | |
137 | PWM_CTRL_CFG_DIV_SHIFT(pwm->hwpwm); | |
22e8e19a | 138 | img_pwm_writel(imgchip, PWM_CTRL_CFG, val); |
277bb6a2 NT |
139 | |
140 | val = (duty << PWM_CH_CFG_DUTY_SHIFT) | | |
141 | (timebase << PWM_CH_CFG_TMBASE_SHIFT); | |
22e8e19a | 142 | img_pwm_writel(imgchip, PWM_CH_CFG(pwm->hwpwm), val); |
277bb6a2 | 143 | |
e690ae52 EB |
144 | pm_runtime_mark_last_busy(chip->dev); |
145 | pm_runtime_put_autosuspend(chip->dev); | |
146 | ||
277bb6a2 NT |
147 | return 0; |
148 | } | |
149 | ||
150 | static int img_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) | |
151 | { | |
152 | u32 val; | |
22e8e19a | 153 | struct img_pwm_chip *imgchip = to_img_pwm_chip(chip); |
e690ae52 EB |
154 | int ret; |
155 | ||
fde25294 | 156 | ret = pm_runtime_resume_and_get(chip->dev); |
e690ae52 EB |
157 | if (ret < 0) |
158 | return ret; | |
277bb6a2 | 159 | |
22e8e19a | 160 | val = img_pwm_readl(imgchip, PWM_CTRL_CFG); |
277bb6a2 | 161 | val |= BIT(pwm->hwpwm); |
22e8e19a | 162 | img_pwm_writel(imgchip, PWM_CTRL_CFG, val); |
277bb6a2 | 163 | |
50f21510 UKK |
164 | regmap_clear_bits(imgchip->periph_regs, PERIP_PWM_PDM_CONTROL, |
165 | PERIP_PWM_PDM_CONTROL_CH_MASK << | |
166 | PERIP_PWM_PDM_CONTROL_CH_SHIFT(pwm->hwpwm)); | |
277bb6a2 NT |
167 | |
168 | return 0; | |
169 | } | |
170 | ||
171 | static void img_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) | |
172 | { | |
173 | u32 val; | |
22e8e19a | 174 | struct img_pwm_chip *imgchip = to_img_pwm_chip(chip); |
277bb6a2 | 175 | |
22e8e19a | 176 | val = img_pwm_readl(imgchip, PWM_CTRL_CFG); |
277bb6a2 | 177 | val &= ~BIT(pwm->hwpwm); |
22e8e19a | 178 | img_pwm_writel(imgchip, PWM_CTRL_CFG, val); |
e690ae52 EB |
179 | |
180 | pm_runtime_mark_last_busy(chip->dev); | |
181 | pm_runtime_put_autosuspend(chip->dev); | |
277bb6a2 NT |
182 | } |
183 | ||
0ee11b87 UKK |
184 | static int img_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, |
185 | const struct pwm_state *state) | |
186 | { | |
187 | int err; | |
188 | ||
189 | if (state->polarity != PWM_POLARITY_NORMAL) | |
190 | return -EINVAL; | |
191 | ||
192 | if (!state->enabled) { | |
193 | if (pwm->state.enabled) | |
194 | img_pwm_disable(chip, pwm); | |
195 | ||
196 | return 0; | |
197 | } | |
198 | ||
199 | err = img_pwm_config(pwm->chip, pwm, state->duty_cycle, state->period); | |
200 | if (err) | |
201 | return err; | |
202 | ||
203 | if (!pwm->state.enabled) | |
204 | err = img_pwm_enable(chip, pwm); | |
205 | ||
206 | return err; | |
207 | } | |
208 | ||
277bb6a2 | 209 | static const struct pwm_ops img_pwm_ops = { |
0ee11b87 | 210 | .apply = img_pwm_apply, |
277bb6a2 NT |
211 | .owner = THIS_MODULE, |
212 | }; | |
213 | ||
1e70897d NT |
214 | static const struct img_pwm_soc_data pistachio_pwm = { |
215 | .max_timebase = 255, | |
216 | }; | |
217 | ||
218 | static const struct of_device_id img_pwm_of_match[] = { | |
219 | { | |
220 | .compatible = "img,pistachio-pwm", | |
221 | .data = &pistachio_pwm, | |
222 | }, | |
223 | { } | |
224 | }; | |
225 | MODULE_DEVICE_TABLE(of, img_pwm_of_match); | |
226 | ||
e690ae52 EB |
227 | static int img_pwm_runtime_suspend(struct device *dev) |
228 | { | |
22e8e19a | 229 | struct img_pwm_chip *imgchip = dev_get_drvdata(dev); |
e690ae52 | 230 | |
22e8e19a UKK |
231 | clk_disable_unprepare(imgchip->pwm_clk); |
232 | clk_disable_unprepare(imgchip->sys_clk); | |
e690ae52 EB |
233 | |
234 | return 0; | |
235 | } | |
236 | ||
237 | static int img_pwm_runtime_resume(struct device *dev) | |
238 | { | |
22e8e19a | 239 | struct img_pwm_chip *imgchip = dev_get_drvdata(dev); |
e690ae52 EB |
240 | int ret; |
241 | ||
22e8e19a | 242 | ret = clk_prepare_enable(imgchip->sys_clk); |
e690ae52 EB |
243 | if (ret < 0) { |
244 | dev_err(dev, "could not prepare or enable sys clock\n"); | |
245 | return ret; | |
246 | } | |
247 | ||
22e8e19a | 248 | ret = clk_prepare_enable(imgchip->pwm_clk); |
e690ae52 EB |
249 | if (ret < 0) { |
250 | dev_err(dev, "could not prepare or enable pwm clock\n"); | |
22e8e19a | 251 | clk_disable_unprepare(imgchip->sys_clk); |
e690ae52 EB |
252 | return ret; |
253 | } | |
254 | ||
255 | return 0; | |
256 | } | |
257 | ||
277bb6a2 NT |
258 | static int img_pwm_probe(struct platform_device *pdev) |
259 | { | |
260 | int ret; | |
1e70897d NT |
261 | u64 val; |
262 | unsigned long clk_rate; | |
22e8e19a | 263 | struct img_pwm_chip *imgchip; |
1e70897d | 264 | const struct of_device_id *of_dev_id; |
277bb6a2 | 265 | |
22e8e19a UKK |
266 | imgchip = devm_kzalloc(&pdev->dev, sizeof(*imgchip), GFP_KERNEL); |
267 | if (!imgchip) | |
277bb6a2 NT |
268 | return -ENOMEM; |
269 | ||
22e8e19a | 270 | imgchip->dev = &pdev->dev; |
277bb6a2 | 271 | |
22e8e19a UKK |
272 | imgchip->base = devm_platform_ioremap_resource(pdev, 0); |
273 | if (IS_ERR(imgchip->base)) | |
274 | return PTR_ERR(imgchip->base); | |
277bb6a2 | 275 | |
1e70897d NT |
276 | of_dev_id = of_match_device(img_pwm_of_match, &pdev->dev); |
277 | if (!of_dev_id) | |
278 | return -ENODEV; | |
22e8e19a | 279 | imgchip->data = of_dev_id->data; |
1e70897d | 280 | |
22e8e19a UKK |
281 | imgchip->periph_regs = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, |
282 | "img,cr-periph"); | |
283 | if (IS_ERR(imgchip->periph_regs)) | |
284 | return PTR_ERR(imgchip->periph_regs); | |
277bb6a2 | 285 | |
22e8e19a UKK |
286 | imgchip->sys_clk = devm_clk_get(&pdev->dev, "sys"); |
287 | if (IS_ERR(imgchip->sys_clk)) { | |
277bb6a2 | 288 | dev_err(&pdev->dev, "failed to get system clock\n"); |
22e8e19a | 289 | return PTR_ERR(imgchip->sys_clk); |
277bb6a2 NT |
290 | } |
291 | ||
22e8e19a UKK |
292 | imgchip->pwm_clk = devm_clk_get(&pdev->dev, "imgchip"); |
293 | if (IS_ERR(imgchip->pwm_clk)) { | |
294 | dev_err(&pdev->dev, "failed to get imgchip clock\n"); | |
295 | return PTR_ERR(imgchip->pwm_clk); | |
277bb6a2 NT |
296 | } |
297 | ||
22e8e19a | 298 | platform_set_drvdata(pdev, imgchip); |
b39c0615 | 299 | |
e690ae52 EB |
300 | pm_runtime_set_autosuspend_delay(&pdev->dev, IMG_PWM_PM_TIMEOUT); |
301 | pm_runtime_use_autosuspend(&pdev->dev); | |
302 | pm_runtime_enable(&pdev->dev); | |
303 | if (!pm_runtime_enabled(&pdev->dev)) { | |
304 | ret = img_pwm_runtime_resume(&pdev->dev); | |
305 | if (ret) | |
306 | goto err_pm_disable; | |
277bb6a2 NT |
307 | } |
308 | ||
22e8e19a | 309 | clk_rate = clk_get_rate(imgchip->pwm_clk); |
bea307c1 | 310 | if (!clk_rate) { |
22e8e19a | 311 | dev_err(&pdev->dev, "imgchip clock has no frequency\n"); |
bea307c1 | 312 | ret = -EINVAL; |
e690ae52 | 313 | goto err_suspend; |
bea307c1 | 314 | } |
1e70897d NT |
315 | |
316 | /* The maximum input clock divider is 512 */ | |
22e8e19a | 317 | val = (u64)NSEC_PER_SEC * 512 * imgchip->data->max_timebase; |
1e70897d | 318 | do_div(val, clk_rate); |
22e8e19a | 319 | imgchip->max_period_ns = val; |
1e70897d NT |
320 | |
321 | val = (u64)NSEC_PER_SEC * MIN_TMBASE_STEPS; | |
322 | do_div(val, clk_rate); | |
22e8e19a | 323 | imgchip->min_period_ns = val; |
1e70897d | 324 | |
22e8e19a UKK |
325 | imgchip->chip.dev = &pdev->dev; |
326 | imgchip->chip.ops = &img_pwm_ops; | |
327 | imgchip->chip.npwm = IMG_PWM_NPWM; | |
277bb6a2 | 328 | |
22e8e19a | 329 | ret = pwmchip_add(&imgchip->chip); |
277bb6a2 NT |
330 | if (ret < 0) { |
331 | dev_err(&pdev->dev, "pwmchip_add failed: %d\n", ret); | |
e690ae52 | 332 | goto err_suspend; |
277bb6a2 NT |
333 | } |
334 | ||
277bb6a2 NT |
335 | return 0; |
336 | ||
e690ae52 EB |
337 | err_suspend: |
338 | if (!pm_runtime_enabled(&pdev->dev)) | |
339 | img_pwm_runtime_suspend(&pdev->dev); | |
340 | err_pm_disable: | |
341 | pm_runtime_disable(&pdev->dev); | |
342 | pm_runtime_dont_use_autosuspend(&pdev->dev); | |
277bb6a2 NT |
343 | return ret; |
344 | } | |
345 | ||
f365a946 | 346 | static void img_pwm_remove(struct platform_device *pdev) |
277bb6a2 | 347 | { |
22e8e19a | 348 | struct img_pwm_chip *imgchip = platform_get_drvdata(pdev); |
277bb6a2 | 349 | |
e690ae52 EB |
350 | pm_runtime_disable(&pdev->dev); |
351 | if (!pm_runtime_status_suspended(&pdev->dev)) | |
352 | img_pwm_runtime_suspend(&pdev->dev); | |
277bb6a2 | 353 | |
22e8e19a | 354 | pwmchip_remove(&imgchip->chip); |
277bb6a2 NT |
355 | } |
356 | ||
a18afce5 EB |
357 | #ifdef CONFIG_PM_SLEEP |
358 | static int img_pwm_suspend(struct device *dev) | |
359 | { | |
22e8e19a | 360 | struct img_pwm_chip *imgchip = dev_get_drvdata(dev); |
e690ae52 EB |
361 | int i, ret; |
362 | ||
363 | if (pm_runtime_status_suspended(dev)) { | |
364 | ret = img_pwm_runtime_resume(dev); | |
365 | if (ret) | |
366 | return ret; | |
367 | } | |
a18afce5 | 368 | |
22e8e19a UKK |
369 | for (i = 0; i < imgchip->chip.npwm; i++) |
370 | imgchip->suspend_ch_cfg[i] = img_pwm_readl(imgchip, | |
371 | PWM_CH_CFG(i)); | |
a18afce5 | 372 | |
22e8e19a | 373 | imgchip->suspend_ctrl_cfg = img_pwm_readl(imgchip, PWM_CTRL_CFG); |
a18afce5 | 374 | |
e690ae52 | 375 | img_pwm_runtime_suspend(dev); |
a18afce5 EB |
376 | |
377 | return 0; | |
378 | } | |
379 | ||
380 | static int img_pwm_resume(struct device *dev) | |
381 | { | |
22e8e19a | 382 | struct img_pwm_chip *imgchip = dev_get_drvdata(dev); |
a18afce5 EB |
383 | int ret; |
384 | int i; | |
385 | ||
e690ae52 EB |
386 | ret = img_pwm_runtime_resume(dev); |
387 | if (ret) | |
a18afce5 | 388 | return ret; |
a18afce5 | 389 | |
22e8e19a UKK |
390 | for (i = 0; i < imgchip->chip.npwm; i++) |
391 | img_pwm_writel(imgchip, PWM_CH_CFG(i), | |
392 | imgchip->suspend_ch_cfg[i]); | |
a18afce5 | 393 | |
22e8e19a | 394 | img_pwm_writel(imgchip, PWM_CTRL_CFG, imgchip->suspend_ctrl_cfg); |
a18afce5 | 395 | |
22e8e19a UKK |
396 | for (i = 0; i < imgchip->chip.npwm; i++) |
397 | if (imgchip->suspend_ctrl_cfg & BIT(i)) | |
50f21510 UKK |
398 | regmap_clear_bits(imgchip->periph_regs, |
399 | PERIP_PWM_PDM_CONTROL, | |
400 | PERIP_PWM_PDM_CONTROL_CH_MASK << | |
401 | PERIP_PWM_PDM_CONTROL_CH_SHIFT(i)); | |
a18afce5 | 402 | |
e690ae52 EB |
403 | if (pm_runtime_status_suspended(dev)) |
404 | img_pwm_runtime_suspend(dev); | |
405 | ||
a18afce5 EB |
406 | return 0; |
407 | } | |
408 | #endif /* CONFIG_PM */ | |
409 | ||
e690ae52 EB |
410 | static const struct dev_pm_ops img_pwm_pm_ops = { |
411 | SET_RUNTIME_PM_OPS(img_pwm_runtime_suspend, | |
412 | img_pwm_runtime_resume, | |
413 | NULL) | |
414 | SET_SYSTEM_SLEEP_PM_OPS(img_pwm_suspend, img_pwm_resume) | |
415 | }; | |
a18afce5 | 416 | |
277bb6a2 NT |
417 | static struct platform_driver img_pwm_driver = { |
418 | .driver = { | |
419 | .name = "img-pwm", | |
a18afce5 | 420 | .pm = &img_pwm_pm_ops, |
277bb6a2 NT |
421 | .of_match_table = img_pwm_of_match, |
422 | }, | |
423 | .probe = img_pwm_probe, | |
f365a946 | 424 | .remove_new = img_pwm_remove, |
277bb6a2 NT |
425 | }; |
426 | module_platform_driver(img_pwm_driver); | |
427 | ||
428 | MODULE_AUTHOR("Sai Masarapu <Sai.Masarapu@imgtec.com>"); | |
429 | MODULE_DESCRIPTION("Imagination Technologies PWM DAC driver"); | |
430 | MODULE_LICENSE("GPL v2"); |