1
2
3
4
5
6
7
8
9
10
11
12
13#include <linux/clk.h>
14#include <linux/io.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/platform_device.h>
18#include <linux/pwm.h>
19#include <linux/slab.h>
20
21#define BERLIN_PWM_EN 0x0
22#define BERLIN_PWM_ENABLE BIT(0)
23#define BERLIN_PWM_CONTROL 0x4
24
25
26
27
28
29
30
31
32
33
34
35#define BERLIN_PWM_PRESCALE_4096 0x7
36#define BERLIN_PWM_INVERT_POLARITY BIT(3)
37#define BERLIN_PWM_DUTY 0x8
38#define BERLIN_PWM_TCNT 0xc
39#define BERLIN_PWM_MAX_TCNT 65535
40
41struct berlin_pwm_channel {
42 u32 enable;
43 u32 ctrl;
44 u32 duty;
45 u32 tcnt;
46};
47
48struct berlin_pwm_chip {
49 struct pwm_chip chip;
50 struct clk *clk;
51 void __iomem *base;
52};
53
54static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip)
55{
56 return container_of(chip, struct berlin_pwm_chip, chip);
57}
58
59static inline u32 berlin_pwm_readl(struct berlin_pwm_chip *chip,
60 unsigned int channel, unsigned long offset)
61{
62 return readl_relaxed(chip->base + channel * 0x10 + offset);
63}
64
65static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip,
66 unsigned int channel, u32 value,
67 unsigned long offset)
68{
69 writel_relaxed(value, chip->base + channel * 0x10 + offset);
70}
71
72static int berlin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
73{
74 struct berlin_pwm_channel *channel;
75
76 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
77 if (!channel)
78 return -ENOMEM;
79
80 return pwm_set_chip_data(pwm, channel);
81}
82
83static void berlin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
84{
85 struct berlin_pwm_channel *channel = pwm_get_chip_data(pwm);
86
87 kfree(channel);
88}
89
90static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev,
91 int duty_ns, int period_ns)
92{
93 struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
94 bool prescale_4096 = false;
95 u32 value, duty, period;
96 u64 cycles;
97
98 cycles = clk_get_rate(pwm->clk);
99 cycles *= period_ns;
100 do_div(cycles, NSEC_PER_SEC);
101
102 if (cycles > BERLIN_PWM_MAX_TCNT) {
103 prescale_4096 = true;
104 cycles >>= 12;
105
106 if (cycles > BERLIN_PWM_MAX_TCNT)
107 return -ERANGE;
108 }
109
110 period = cycles;
111 cycles *= duty_ns;
112 do_div(cycles, period_ns);
113 duty = cycles;
114
115 value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
116 if (prescale_4096)
117 value |= BERLIN_PWM_PRESCALE_4096;
118 else
119 value &= ~BERLIN_PWM_PRESCALE_4096;
120 berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL);
121
122 berlin_pwm_writel(pwm, pwm_dev->hwpwm, duty, BERLIN_PWM_DUTY);
123 berlin_pwm_writel(pwm, pwm_dev->hwpwm, period, BERLIN_PWM_TCNT);
124
125 return 0;
126}
127
128static int berlin_pwm_set_polarity(struct pwm_chip *chip,
129 struct pwm_device *pwm_dev,
130 enum pwm_polarity polarity)
131{
132 struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
133 u32 value;
134
135 value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
136
137 if (polarity == PWM_POLARITY_NORMAL)
138 value &= ~BERLIN_PWM_INVERT_POLARITY;
139 else
140 value |= BERLIN_PWM_INVERT_POLARITY;
141
142 berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL);
143
144 return 0;
145}
146
147static int berlin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm_dev)
148{
149 struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
150 u32 value;
151
152 value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
153 value |= BERLIN_PWM_ENABLE;
154 berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN);
155
156 return 0;
157}
158
159static void berlin_pwm_disable(struct pwm_chip *chip,
160 struct pwm_device *pwm_dev)
161{
162 struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
163 u32 value;
164
165 value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
166 value &= ~BERLIN_PWM_ENABLE;
167 berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN);
168}
169
170static const struct pwm_ops berlin_pwm_ops = {
171 .request = berlin_pwm_request,
172 .free = berlin_pwm_free,
173 .config = berlin_pwm_config,
174 .set_polarity = berlin_pwm_set_polarity,
175 .enable = berlin_pwm_enable,
176 .disable = berlin_pwm_disable,
177 .owner = THIS_MODULE,
178};
179
180static const struct of_device_id berlin_pwm_match[] = {
181 { .compatible = "marvell,berlin-pwm" },
182 { },
183};
184MODULE_DEVICE_TABLE(of, berlin_pwm_match);
185
186static int berlin_pwm_probe(struct platform_device *pdev)
187{
188 struct berlin_pwm_chip *pwm;
189 int ret;
190
191 pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
192 if (!pwm)
193 return -ENOMEM;
194
195 pwm->base = devm_platform_ioremap_resource(pdev, 0);
196 if (IS_ERR(pwm->base))
197 return PTR_ERR(pwm->base);
198
199 pwm->clk = devm_clk_get(&pdev->dev, NULL);
200 if (IS_ERR(pwm->clk))
201 return PTR_ERR(pwm->clk);
202
203 ret = clk_prepare_enable(pwm->clk);
204 if (ret)
205 return ret;
206
207 pwm->chip.dev = &pdev->dev;
208 pwm->chip.ops = &berlin_pwm_ops;
209 pwm->chip.base = -1;
210 pwm->chip.npwm = 4;
211 pwm->chip.of_xlate = of_pwm_xlate_with_flags;
212 pwm->chip.of_pwm_n_cells = 3;
213
214 ret = pwmchip_add(&pwm->chip);
215 if (ret < 0) {
216 dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
217 clk_disable_unprepare(pwm->clk);
218 return ret;
219 }
220
221 platform_set_drvdata(pdev, pwm);
222
223 return 0;
224}
225
226static int berlin_pwm_remove(struct platform_device *pdev)
227{
228 struct berlin_pwm_chip *pwm = platform_get_drvdata(pdev);
229 int ret;
230
231 ret = pwmchip_remove(&pwm->chip);
232 clk_disable_unprepare(pwm->clk);
233
234 return ret;
235}
236
237#ifdef CONFIG_PM_SLEEP
238static int berlin_pwm_suspend(struct device *dev)
239{
240 struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
241 unsigned int i;
242
243 for (i = 0; i < pwm->chip.npwm; i++) {
244 struct berlin_pwm_channel *channel;
245
246 channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
247 if (!channel)
248 continue;
249
250 channel->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE);
251 channel->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL);
252 channel->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY);
253 channel->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT);
254 }
255
256 clk_disable_unprepare(pwm->clk);
257
258 return 0;
259}
260
261static int berlin_pwm_resume(struct device *dev)
262{
263 struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
264 unsigned int i;
265 int ret;
266
267 ret = clk_prepare_enable(pwm->clk);
268 if (ret)
269 return ret;
270
271 for (i = 0; i < pwm->chip.npwm; i++) {
272 struct berlin_pwm_channel *channel;
273
274 channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
275 if (!channel)
276 continue;
277
278 berlin_pwm_writel(pwm, i, channel->ctrl, BERLIN_PWM_CONTROL);
279 berlin_pwm_writel(pwm, i, channel->duty, BERLIN_PWM_DUTY);
280 berlin_pwm_writel(pwm, i, channel->tcnt, BERLIN_PWM_TCNT);
281 berlin_pwm_writel(pwm, i, channel->enable, BERLIN_PWM_ENABLE);
282 }
283
284 return 0;
285}
286#endif
287
288static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
289 berlin_pwm_resume);
290
291static struct platform_driver berlin_pwm_driver = {
292 .probe = berlin_pwm_probe,
293 .remove = berlin_pwm_remove,
294 .driver = {
295 .name = "berlin-pwm",
296 .of_match_table = berlin_pwm_match,
297 .pm = &berlin_pwm_pm_ops,
298 },
299};
300module_platform_driver(berlin_pwm_driver);
301
302MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
303MODULE_DESCRIPTION("Marvell Berlin PWM driver");
304MODULE_LICENSE("GPL v2");
305
