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