aboutsummaryrefslogtreecommitdiff
path: root/drivers/pwm/pwm-mediatek.c
blob: 0d4dd80e9f07f608fe4cccc050aaa8a97b23a972 (plain)
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
// SPDX-License-Identifier: GPL-2.0
/*
 * MediaTek Pulse Width Modulator driver
 *
 * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
 * Copyright (C) 2017 Zhi Mao <zhi.mao@mediatek.com>
 *
 */

#include <linux/err.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/slab.h>
#include <linux/types.h>

/* PWM registers and bits definitions */
#define PWMCON			0x00
#define PWMHDUR			0x04
#define PWMLDUR			0x08
#define PWMGDUR			0x0c
#define PWMWAVENUM		0x28
#define PWMDWIDTH		0x2c
#define PWM45DWIDTH_FIXUP	0x30
#define PWMTHRES		0x30
#define PWM45THRES_FIXUP	0x34
#define PWM_CK_26M_SEL		0x210

#define PWM_CLK_DIV_MAX		7

struct pwm_mediatek_of_data {
	unsigned int num_pwms;
	bool pwm45_fixup;
	bool has_ck_26m_sel;
};

/**
 * struct pwm_mediatek_chip - struct representing PWM chip
 * @chip: linux PWM chip representation
 * @regs: base address of PWM chip
 * @clk_top: the top clock generator
 * @clk_main: the clock used by PWM core
 * @clk_pwms: the clock used by each PWM channel
 * @clk_freq: the fix clock frequency of legacy MIPS SoC
 * @soc: pointer to chip's platform data
 */
struct pwm_mediatek_chip {
	struct pwm_chip chip;
	void __iomem *regs;
	struct clk *clk_top;
	struct clk *clk_main;
	struct clk **clk_pwms;
	const struct pwm_mediatek_of_data *soc;
};

static const unsigned int pwm_mediatek_reg_offset[] = {
	0x0010, 0x0050, 0x0090, 0x00d0, 0x0110, 0x0150, 0x0190, 0x0220
};

static inline struct pwm_mediatek_chip *
to_pwm_mediatek_chip(struct pwm_chip *chip)
{
	return container_of(chip, struct pwm_mediatek_chip, chip);
}

static int pwm_mediatek_clk_enable(struct pwm_chip *chip,
				   struct pwm_device *pwm)
{
	struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
	int ret;

	ret = clk_prepare_enable(pc->clk_top);
	if (ret < 0)
		return ret;

	ret = clk_prepare_enable(pc->clk_main);
	if (ret < 0)
		goto disable_clk_top;

	ret = clk_prepare_enable(pc->clk_pwms[pwm->hwpwm]);
	if (ret < 0)
		goto disable_clk_main;

	return 0;

disable_clk_main:
	clk_disable_unprepare(pc->clk_main);
disable_clk_top:
	clk_disable_unprepare(pc->clk_top);

	return ret;
}

static void pwm_mediatek_clk_disable(struct pwm_chip *chip,
				     struct pwm_device *pwm)
{
	struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);

	clk_disable_unprepare(pc->clk_pwms[pwm->hwpwm]);
	clk_disable_unprepare(pc->clk_main);
	clk_disable_unprepare(pc->clk_top);
}

static inline void pwm_mediatek_writel(struct pwm_mediatek_chip *chip,
				       unsigned int num, unsigned int offset,
				       u32 value)
{
	writel(value, chip->regs + pwm_mediatek_reg_offset[num] + offset);
}

static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
			       int duty_ns, int period_ns)
{
	struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
	u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH,
	    reg_thres = PWMTHRES;
	u64 resolution;
	int ret;

	ret = pwm_mediatek_clk_enable(chip, pwm);

	if (ret < 0)
		return ret;

	/* Make sure we use the bus clock and not the 26MHz clock */
	if (pc->soc->has_ck_26m_sel)
		writel(0, pc->regs + PWM_CK_26M_SEL);

	/* Using resolution in picosecond gets accuracy higher */
	resolution = (u64)NSEC_PER_SEC * 1000;
	do_div(resolution, clk_get_rate(pc->clk_pwms[pwm->hwpwm]));

	cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution);
	while (cnt_period > 8191) {
		resolution *= 2;
		clkdiv++;
		cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000,
						   resolution);
	}

	if (clkdiv > PWM_CLK_DIV_MAX) {
		pwm_mediatek_clk_disable(chip, pwm);
		dev_err(chip->dev, "period %d not supported\n", period_ns);
		return -EINVAL;
	}

	if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) {
		/*
		 * PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES
		 * from the other PWMs on MT7623.
		 */
		reg_width = PWM45DWIDTH_FIXUP;
		reg_thres = PWM45THRES_FIXUP;
	}

	cnt_duty = DIV_ROUND_CLOSEST_ULL((u64)duty_ns * 1000, resolution);
	pwm_mediatek_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv);
	pwm_mediatek_writel(pc, pwm->hwpwm, reg_width, cnt_period);
	pwm_mediatek_writel(pc, pwm->hwpwm, reg_thres, cnt_duty);

	pwm_mediatek_clk_disable(chip, pwm);

	return 0;
}

static int pwm_mediatek_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
	u32 value;
	int ret;

	ret = pwm_mediatek_clk_enable(chip, pwm);
	if (ret < 0)
		return ret;

	value = readl(pc->regs);
	value |= BIT(pwm->hwpwm);
	writel(value, pc->regs);

	return 0;
}

static void pwm_mediatek_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
	u32 value;

	value = readl(pc->regs);
	value &= ~BIT(pwm->hwpwm);
	writel(value, pc->regs);

	pwm_mediatek_clk_disable(chip, pwm);
}

static const struct pwm_ops pwm_mediatek_ops = {
	.config = pwm_mediatek_config,
	.enable = pwm_mediatek_enable,
	.disable = pwm_mediatek_disable,
	.owner = THIS_MODULE,
};

static int pwm_mediatek_probe(struct platform_device *pdev)
{
	struct pwm_mediatek_chip *pc;
	unsigned int i;
	int ret;

	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
	if (!pc)
		return -ENOMEM;

	pc->soc = of_device_get_match_data(&pdev->dev);

	pc->regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(pc->regs))
		return PTR_ERR(pc->regs);

	pc->clk_pwms = devm_kcalloc(&pdev->dev, pc->soc->num_pwms,
				    sizeof(*pc->clk_pwms), GFP_KERNEL);
	if (!pc->clk_pwms)
		return -ENOMEM;

	pc->clk_top = devm_clk_get(&pdev->dev, "top");
	if (IS_ERR(pc->clk_top)) {
		dev_err(&pdev->dev, "clock: top fail: %ld\n",
			PTR_ERR(pc->clk_top));
		return PTR_ERR(pc->clk_top);
	}

	pc->clk_main = devm_clk_get(&pdev->dev, "main");
	if (IS_ERR(pc->clk_main)) {
		dev_err(&pdev->dev, "clock: main fail: %ld\n",
			PTR_ERR(pc->clk_main));
		return PTR_ERR(pc->clk_main);
	}

	for (i = 0; i < pc->soc->num_pwms; i++) {
		char name[8];

		snprintf(name, sizeof(name), "pwm%d", i + 1);

		pc->clk_pwms[i] = devm_clk_get(&pdev->dev, name);
		if (IS_ERR(pc->clk_pwms[i])) {
			dev_err(&pdev->dev, "clock: %s fail: %ld\n",
				name, PTR_ERR(pc->clk_pwms[i]));
			return PTR_ERR(pc->clk_pwms[i]);
		}
	}

	pc->chip.dev = &pdev->dev;
	pc->chip.ops = &pwm_mediatek_ops;
	pc->chip.npwm = pc->soc->num_pwms;

	ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
	if (ret < 0) {
		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
		return ret;
	}

	return 0;
}

static const struct pwm_mediatek_of_data mt2712_pwm_data = {
	.num_pwms = 8,
	.pwm45_fixup = false,
	.has_ck_26m_sel = false,
};

static const struct pwm_mediatek_of_data mt7622_pwm_data = {
	.num_pwms = 6,
	.pwm45_fixup = false,
	.has_ck_26m_sel = false,
};

static const struct pwm_mediatek_of_data mt7623_pwm_data = {
	.num_pwms = 5,
	.pwm45_fixup = true,
	.has_ck_26m_sel = false,
};

static const struct pwm_mediatek_of_data mt7628_pwm_data = {
	.num_pwms = 4,
	.pwm45_fixup = true,
	.has_ck_26m_sel = false,
};

static const struct pwm_mediatek_of_data mt7629_pwm_data = {
	.num_pwms = 1,
	.pwm45_fixup = false,
	.has_ck_26m_sel = false,
};

static const struct pwm_mediatek_of_data mt8183_pwm_data = {
	.num_pwms = 4,
	.pwm45_fixup = false,
	.has_ck_26m_sel = true,
};

static const struct pwm_mediatek_of_data mt8516_pwm_data = {
	.num_pwms = 5,
	.pwm45_fixup = false,
	.has_ck_26m_sel = true,
};

static const struct of_device_id pwm_mediatek_of_match[] = {
	{ .compatible = "mediatek,mt2712-pwm", .data = &mt2712_pwm_data },
	{ .compatible = "mediatek,mt7622-pwm", .data = &mt7622_pwm_data },
	{ .compatible = "mediatek,mt7623-pwm", .data = &mt7623_pwm_data },
	{ .compatible = "mediatek,mt7628-pwm", .data = &mt7628_pwm_data },
	{ .compatible = "mediatek,mt7629-pwm", .data = &mt7629_pwm_data },
	{ .compatible = "mediatek,mt8183-pwm", .data = &mt8183_pwm_data },
	{ .compatible = "mediatek,mt8516-pwm", .data = &mt8516_pwm_data },
	{ },
};
MODULE_DEVICE_TABLE(of, pwm_mediatek_of_match);

static struct platform_driver pwm_mediatek_driver = {
	.driver = {
		.name = "pwm-mediatek",
		.of_match_table = pwm_mediatek_of_match,
	},
	.probe = pwm_mediatek_probe,
};
module_platform_driver(pwm_mediatek_driver);

MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
MODULE_LICENSE("GPL v2");