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