2 * PWM driver for Rockchip SoCs
4 * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
5 * Copyright (C) 2014 ROCKCHIP, Inc.
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
12 #include <linux/clk.h>
14 #include <linux/module.h>
16 #include <linux/of_device.h>
17 #include <linux/platform_device.h>
18 #include <linux/pwm.h>
19 #include <linux/time.h>
20 #include <linux/rk_fb.h>
22 #define PWM_CTRL_TIMER_EN (1 << 0)
23 #define PWM_CTRL_OUTPUT_EN (1 << 3)
25 #define PWM_ENABLE (1 << 0)
26 #define PWM_CONTINUOUS (1 << 1)
27 #define PWM_DUTY_POSITIVE (1 << 3)
28 #define PWM_DUTY_NEGATIVE (0 << 3)
29 #define PWM_INACTIVE_NEGATIVE (0 << 4)
30 #define PWM_INACTIVE_POSITIVE (1 << 4)
31 #define PWM_OUTPUT_LEFT (0 << 5)
32 #define PWM_LP_DISABLE (0 << 8)
34 struct rockchip_pwm_chip {
38 const struct rockchip_pwm_data *data;
42 struct rockchip_pwm_regs {
49 struct rockchip_pwm_data {
50 struct rockchip_pwm_regs regs;
51 unsigned int prescaler;
52 bool supports_polarity;
53 const struct pwm_ops *ops;
55 void (*set_enable)(struct pwm_chip *chip,
56 struct pwm_device *pwm, bool enable,
57 enum pwm_polarity polarity);
58 void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm,
59 struct pwm_state *state);
62 static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
64 return container_of(c, struct rockchip_pwm_chip, chip);
67 static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
68 struct pwm_device *pwm, bool enable,
69 enum pwm_polarity polarity)
71 struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
72 u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
75 val = readl_relaxed(pc->base + pc->data->regs.ctrl);
82 writel_relaxed(val, pc->base + pc->data->regs.ctrl);
85 static void rockchip_pwm_get_state_v1(struct pwm_chip *chip,
86 struct pwm_device *pwm,
87 struct pwm_state *state)
89 struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
90 u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
93 val = readl_relaxed(pc->base + pc->data->regs.ctrl);
94 if ((val & enable_conf) == enable_conf)
95 state->enabled = true;
98 static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
99 struct pwm_device *pwm, bool enable,
100 enum pwm_polarity polarity)
102 struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
103 u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
107 if (polarity == PWM_POLARITY_INVERSED)
108 enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
110 enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
112 val = readl_relaxed(pc->base + pc->data->regs.ctrl);
113 val &= ~(GENMASK(5, 0) | BIT(8));
120 writel_relaxed(val, pc->base + pc->data->regs.ctrl);
123 static void rockchip_pwm_get_state_v2(struct pwm_chip *chip,
124 struct pwm_device *pwm,
125 struct pwm_state *state)
127 struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
128 u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
132 val = readl_relaxed(pc->base + pc->data->regs.ctrl);
133 if ((val & enable_conf) != enable_conf)
136 state->enabled = true;
138 if (!(val & PWM_DUTY_POSITIVE))
139 state->polarity = PWM_POLARITY_INVERSED;
142 static void rockchip_pwm_get_state(struct pwm_chip *chip,
143 struct pwm_device *pwm,
144 struct pwm_state *state)
146 struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
147 unsigned long clk_rate;
151 ret = clk_enable(pc->clk);
155 clk_rate = clk_get_rate(pc->clk);
157 tmp = readl_relaxed(pc->base + pc->data->regs.period);
158 tmp *= pc->data->prescaler * NSEC_PER_SEC;
159 state->period = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
161 tmp = readl_relaxed(pc->base + pc->data->regs.duty);
162 tmp *= pc->data->prescaler * NSEC_PER_SEC;
163 state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
165 pc->data->get_state(chip, pwm, state);
167 clk_disable(pc->clk);
170 static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
171 int duty_ns, int period_ns)
173 struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
174 unsigned long period, duty;
178 clk_rate = clk_get_rate(pc->clk);
181 * Since period and duty cycle registers have a width of 32
182 * bits, every possible input period can be obtained using the
183 * default prescaler value for all practical clock rate values.
185 div = clk_rate * period_ns;
186 period = DIV_ROUND_CLOSEST_ULL(div,
187 pc->data->prescaler * NSEC_PER_SEC);
189 div = clk_rate * duty_ns;
190 duty = DIV_ROUND_CLOSEST_ULL(div, pc->data->prescaler * NSEC_PER_SEC);
192 writel(period, pc->base + pc->data->regs.period);
193 writel(duty, pc->base + pc->data->regs.duty);
195 #ifdef CONFIG_FB_ROCKCHIP
196 if (!pc->data->regs.ctrl) {
197 ret = rk_fb_set_vop_pwm();
199 dev_err(pc->chip.dev, "rk_fb_set_vop_pwm failed: %d\n", ret);
206 static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
207 struct pwm_state *state)
209 struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
210 struct pwm_state curstate;
214 pwm_get_state(pwm, &curstate);
215 enabled = curstate.enabled;
217 ret = clk_enable(pc->pclk);
221 ret = clk_enable(pc->clk);
225 if (state->polarity != curstate.polarity && enabled) {
226 pc->data->set_enable(chip, pwm, false, state->polarity);
230 ret = rockchip_pwm_config(chip, pwm, state->duty_cycle, state->period);
232 if (enabled != curstate.enabled)
233 pc->data->set_enable(chip, pwm, !enabled,
239 if (state->enabled != enabled)
240 pc->data->set_enable(chip, pwm, state->enabled,
244 * Update the state with the real hardware, which can differ a bit
245 * because of period/duty_cycle approximation.
247 rockchip_pwm_get_state(chip, pwm, state);
250 clk_disable(pc->clk);
251 clk_disable(pc->pclk);
256 static const struct pwm_ops rockchip_pwm_ops_v1 = {
257 .get_state = rockchip_pwm_get_state,
258 .apply = rockchip_pwm_apply,
259 .owner = THIS_MODULE,
262 static const struct pwm_ops rockchip_pwm_ops_v2 = {
263 .get_state = rockchip_pwm_get_state,
264 .apply = rockchip_pwm_apply,
265 .owner = THIS_MODULE,
268 static const struct rockchip_pwm_data pwm_data_v1 = {
276 .ops = &rockchip_pwm_ops_v1,
277 .set_enable = rockchip_pwm_set_enable_v1,
278 .get_state = rockchip_pwm_get_state_v1,
281 static const struct rockchip_pwm_data pwm_data_v2 = {
289 .supports_polarity = true,
290 .ops = &rockchip_pwm_ops_v2,
291 .set_enable = rockchip_pwm_set_enable_v2,
292 .get_state = rockchip_pwm_get_state_v2,
295 static const struct rockchip_pwm_data pwm_data_vop = {
303 .supports_polarity = true,
304 .ops = &rockchip_pwm_ops_v2,
305 .set_enable = rockchip_pwm_set_enable_v2,
306 .get_state = rockchip_pwm_get_state_v2,
309 static const struct of_device_id rockchip_pwm_dt_ids[] = {
310 { .compatible = "rockchip,rk2928-pwm", .data = &pwm_data_v1},
311 { .compatible = "rockchip,rk3288-pwm", .data = &pwm_data_v2},
312 { .compatible = "rockchip,rk3328-pwm", .data = &pwm_data_v2},
313 { .compatible = "rockchip,vop-pwm", .data = &pwm_data_vop},
314 { .compatible = "rockchip,rk3399-pwm", .data = &pwm_data_v2},
317 MODULE_DEVICE_TABLE(of, rockchip_pwm_dt_ids);
319 static int rockchip_pwm_probe(struct platform_device *pdev)
321 const struct of_device_id *id;
322 struct rockchip_pwm_chip *pc;
326 id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev);
330 pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
334 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
335 pc->base = devm_ioremap(&pdev->dev, r->start,
337 if (IS_ERR(pc->base))
338 return PTR_ERR(pc->base);
340 pc->clk = devm_clk_get(&pdev->dev, "pwm");
341 count = of_property_count_strings(pdev->dev.of_node, "clock-names");
343 pc->pclk = devm_clk_get(&pdev->dev, "pclk");
347 if (IS_ERR(pc->clk)) {
348 ret = PTR_ERR(pc->clk);
349 if (ret != -EPROBE_DEFER)
350 dev_err(&pdev->dev, "Can't get bus clk: %d\n", ret);
354 if (IS_ERR(pc->pclk)) {
355 ret = PTR_ERR(pc->pclk);
356 if (ret != -EPROBE_DEFER)
357 dev_err(&pdev->dev, "Can't get periph clk: %d\n", ret);
361 ret = clk_prepare_enable(pc->clk);
363 dev_err(&pdev->dev, "Can't prepare bus clk: %d\n", ret);
367 ret = clk_prepare_enable(pc->pclk);
369 dev_err(&pdev->dev, "Can't prepare periph clk: %d\n", ret);
373 platform_set_drvdata(pdev, pc);
376 pc->chip.dev = &pdev->dev;
377 pc->chip.ops = pc->data->ops;
381 if (pc->data->supports_polarity) {
382 pc->chip.of_xlate = of_pwm_xlate_with_flags;
383 pc->chip.of_pwm_n_cells = 3;
386 ret = pwmchip_add(&pc->chip);
388 clk_unprepare(pc->clk);
389 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
393 /* Keep the PWM clk enabled if the PWM appears to be up and running. */
394 if (!pwm_is_enabled(pc->chip.pwms)) {
395 clk_disable(pc->pclk);
396 clk_disable(pc->clk);
402 clk_unprepare(pc->pclk);
404 clk_unprepare(pc->clk);
409 static int rockchip_pwm_remove(struct platform_device *pdev)
411 struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);
414 * Disable the PWM clk before unpreparing it if the PWM device is still
415 * running. This should only happen when the last PWM user left it
416 * enabled, or when nobody requested a PWM that was previously enabled
419 * FIXME: Maybe the core should disable all PWM devices in
420 * pwmchip_remove(). In this case we'd only have to call
421 * clk_unprepare() after pwmchip_remove().
424 if (pwm_is_enabled(pc->chip.pwms)) {
425 clk_disable(pc->pclk);
426 clk_disable(pc->clk);
429 clk_unprepare(pc->pclk);
430 clk_unprepare(pc->clk);
432 return pwmchip_remove(&pc->chip);
435 static struct platform_driver rockchip_pwm_driver = {
437 .name = "rockchip-pwm",
438 .of_match_table = rockchip_pwm_dt_ids,
440 .probe = rockchip_pwm_probe,
441 .remove = rockchip_pwm_remove,
443 module_platform_driver(rockchip_pwm_driver);
445 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
446 MODULE_DESCRIPTION("Rockchip SoC PWM driver");
447 MODULE_LICENSE("GPL v2");