1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* PWM driver for Rockchip SoCs
*
* Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
* Copyright (C) 2014 ROCKCHIP, Inc.
*/
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/time.h>
#define PWM_CTRL_TIMER_EN (1 << 0)
#define PWM_CTRL_OUTPUT_EN (1 << 3)
#define PWM_ENABLE (1 << 0)
#define PWM_CONTINUOUS (1 << 1)
#define PWM_DUTY_POSITIVE (1 << 3)
#define PWM_DUTY_NEGATIVE (0 << 3)
#define PWM_INACTIVE_NEGATIVE (0 << 4)
#define PWM_INACTIVE_POSITIVE (1 << 4)
#define PWM_POLARITY_MASK (PWM_DUTY_POSITIVE | PWM_INACTIVE_POSITIVE)
#define PWM_OUTPUT_LEFT (0 << 5)
#define PWM_LOCK_EN (1 << 6)
#define PWM_LP_DISABLE (0 << 8)
struct rockchip_pwm_chip {
struct pwm_chip chip;
struct clk *clk;
struct clk *pclk;
const struct rockchip_pwm_data *data;
void __iomem *base;
};
struct rockchip_pwm_regs {
unsigned long duty;
unsigned long period;
unsigned long cntr;
unsigned long ctrl;
};
struct rockchip_pwm_data {
struct rockchip_pwm_regs regs;
unsigned int prescaler;
bool supports_polarity;
bool supports_lock;
u32 enable_conf;
};
static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
{
return container_of(c, struct rockchip_pwm_chip, chip);
}
static void rockchip_pwm_get_state(struct pwm_chip *chip,
struct pwm_device *pwm,
struct pwm_state *state)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
u32 enable_conf = pc->data->enable_conf;
unsigned long clk_rate;
u64 tmp;
u32 val;
int ret;
ret = clk_enable(pc->pclk);
if (ret)
return;
clk_rate = clk_get_rate(pc->clk);
tmp = readl_relaxed(pc->base + pc->data->regs.period);
tmp *= pc->data->prescaler * NSEC_PER_SEC;
state->period = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
tmp = readl_relaxed(pc->base + pc->data->regs.duty);
tmp *= pc->data->prescaler * NSEC_PER_SEC;
state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
val = readl_relaxed(pc->base + pc->data->regs.ctrl);
state->enabled = (val & enable_conf) == enable_conf;
if (pc->data->supports_polarity && !(val & PWM_DUTY_POSITIVE))
state->polarity = PWM_POLARITY_INVERSED;
else
state->polarity = PWM_POLARITY_NORMAL;
clk_disable(pc->pclk);
}
static void rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
unsigned long period, duty;
u64 clk_rate, div;
u32 ctrl;
clk_rate = clk_get_rate(pc->clk);
/*
* Since period and duty cycle registers have a width of 32
* bits, every possible input period can be obtained using the
* default prescaler value for all practical clock rate values.
*/
div = clk_rate * state->period;
period = DIV_ROUND_CLOSEST_ULL(div,
pc->data->prescaler * NSEC_PER_SEC);
div = clk_rate * state->duty_cycle;
duty = DIV_ROUND_CLOSEST_ULL(div, pc->data->prescaler * NSEC_PER_SEC);
/*
* Lock the period and duty of previous configuration, then
* change the duty and period, that would not be effective.
*/
ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl);
if (pc->data->supports_lock) {
ctrl |= PWM_LOCK_EN;
writel_relaxed(ctrl, pc->base + pc->data->regs.ctrl);
}
writel(period, pc->base + pc->data->regs.period);
writel(duty, pc->base + pc->data->regs.duty);
if (pc->data->supports_polarity) {
ctrl &= ~PWM_POLARITY_MASK;
if (state->polarity == PWM_POLARITY_INVERSED)
ctrl |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
else
ctrl |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
}
/*
* Unlock and set polarity at the same time,
* the configuration of duty, period and polarity
* would be effective together at next period.
*/
if (pc->data->supports_lock)
ctrl &= ~PWM_LOCK_EN;
writel(ctrl, pc->base + pc->data->regs.ctrl);
}
static int rockchip_pwm_enable(struct pwm_chip *chip,
struct pwm_device *pwm,
bool enable)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
u32 enable_conf = pc->data->enable_conf;
int ret;
u32 val;
if (enable) {
ret = clk_enable(pc->clk);
if (ret)
return ret;
}
val = readl_relaxed(pc->base + pc->data->regs.ctrl);
if (enable)
val |= enable_conf;
else
val &= ~enable_conf;
writel_relaxed(val, pc->base + pc->data->regs.ctrl);
if (!enable)
clk_disable(pc->clk);
return 0;
}
static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
struct pwm_state curstate;
bool enabled;
int ret = 0;
ret = clk_enable(pc->pclk);
if (ret)
return ret;
pwm_get_state(pwm, &curstate);
enabled = curstate.enabled;
if (state->polarity != curstate.polarity && enabled &&
!pc->data->supports_lock) {
ret = rockchip_pwm_enable(chip, pwm, false);
if (ret)
goto out;
enabled = false;
}
rockchip_pwm_config(chip, pwm, state);
if (state->enabled != enabled) {
ret = rockchip_pwm_enable(chip, pwm, state->enabled);
if (ret)
goto out;
}
out:
clk_disable(pc->pclk);
return ret;
}
static const struct pwm_ops rockchip_pwm_ops = {
.get_state = rockchip_pwm_get_state,
.apply = rockchip_pwm_apply,
.owner = THIS_MODULE,
};
static const struct rockchip_pwm_data pwm_data_v1 = {
.regs = {
.duty = 0x04,
.period = 0x08,
.cntr = 0x00,
.ctrl = 0x0c,
},
.prescaler = 2,
.supports_polarity = false,
.supports_lock = false,
.enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN,
};
static const struct rockchip_pwm_data pwm_data_v2 = {
.regs = {
.duty = 0x08,
.period = 0x04,
.cntr = 0x00,
.ctrl = 0x0c,
},
.prescaler = 1,
.supports_polarity = true,
.supports_lock = false,
.enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
PWM_CONTINUOUS,
};
static const struct rockchip_pwm_data pwm_data_vop = {
.regs = {
.duty = 0x08,
.period = 0x04,
.cntr = 0x0c,
.ctrl = 0x00,
},
.prescaler = 1,
.supports_polarity = true,
.supports_lock = false,
.enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
PWM_CONTINUOUS,
};
static const struct rockchip_pwm_data pwm_data_v3 = {
.regs = {
.duty = 0x08,
.period = 0x04,
.cntr = 0x00,
.ctrl = 0x0c,
},
.prescaler = 1,
.supports_polarity = true,
.supports_lock = true,
.enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
PWM_CONTINUOUS,
};
static const struct of_device_id rockchip_pwm_dt_ids[] = {
{ .compatible = "rockchip,rk2928-pwm", .data = &pwm_data_v1},
{ .compatible = "rockchip,rk3288-pwm", .data = &pwm_data_v2},
{ .compatible = "rockchip,vop-pwm", .data = &pwm_data_vop},
{ .compatible = "rockchip,rk3328-pwm", .data = &pwm_data_v3},
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rockchip_pwm_dt_ids);
static int rockchip_pwm_probe(struct platform_device *pdev)
{
const struct of_device_id *id;
struct rockchip_pwm_chip *pc;
u32 enable_conf, ctrl;
int ret, count;
id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev);
if (!id)
return -EINVAL;
pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
if (!pc)
return -ENOMEM;
pc->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(pc->base))
return PTR_ERR(pc->base);
pc->clk = devm_clk_get(&pdev->dev, "pwm");
if (IS_ERR(pc->clk)) {
pc->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(pc->clk))
return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),
"Can't get bus clk\n");
}
count = of_count_phandle_with_args(pdev->dev.of_node,
"clocks", "#clock-cells");
if (count == 2)
pc->pclk = devm_clk_get(&pdev->dev, "pclk");
else
pc->pclk = pc->clk;
if (IS_ERR(pc->pclk)) {
ret = PTR_ERR(pc->pclk);
if (ret != -EPROBE_DEFER)
dev_err(&pdev->dev, "Can't get APB clk: %d\n", ret);
return ret;
}
ret = clk_prepare_enable(pc->clk);
if (ret) {
dev_err(&pdev->dev, "Can't prepare enable bus clk: %d\n", ret);
return ret;
}
ret = clk_prepare_enable(pc->pclk);
if (ret) {
dev_err(&pdev->dev, "Can't prepare enable APB clk: %d\n", ret);
goto err_clk;
}
platform_set_drvdata(pdev, pc);
pc->data = id->data;
pc->chip.dev = &pdev->dev;
pc->chip.ops = &rockchip_pwm_ops;
pc->chip.base = -1;
pc->chip.npwm = 1;
if (pc->data->supports_polarity) {
pc->chip.of_xlate = of_pwm_xlate_with_flags;
pc->chip.of_pwm_n_cells = 3;
}
ret = pwmchip_add(&pc->chip);
if (ret < 0) {
dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
goto err_pclk;
}
/* Keep the PWM clk enabled if the PWM appears to be up and running. */
enable_conf = pc->data->enable_conf;
ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl);
if ((ctrl & enable_conf) != enable_conf)
clk_disable(pc->clk);
clk_disable(pc->pclk);
return 0;
err_pclk:
clk_disable_unprepare(pc->pclk);
err_clk:
clk_disable_unprepare(pc->clk);
return ret;
}
static int rockchip_pwm_remove(struct platform_device *pdev)
{
struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);
/*
* Disable the PWM clk before unpreparing it if the PWM device is still
* running. This should only happen when the last PWM user left it
* enabled, or when nobody requested a PWM that was previously enabled
* by the bootloader.
*
* FIXME: Maybe the core should disable all PWM devices in
* pwmchip_remove(). In this case we'd only have to call
* clk_unprepare() after pwmchip_remove().
*
*/
if (pwm_is_enabled(pc->chip.pwms))
clk_disable(pc->clk);
clk_unprepare(pc->pclk);
clk_unprepare(pc->clk);
return pwmchip_remove(&pc->chip);
}
static struct platform_driver rockchip_pwm_driver = {
.driver = {
.name = "rockchip-pwm",
.of_match_table = rockchip_pwm_dt_ids,
},
.probe = rockchip_pwm_probe,
.remove = rockchip_pwm_remove,
};
module_platform_driver(rockchip_pwm_driver);
MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
MODULE_DESCRIPTION("Rockchip SoC PWM driver");
MODULE_LICENSE("GPL v2");
|