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v6.13.7
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * drivers/pwm/pwm-tegra.c
  4 *
  5 * Tegra pulse-width-modulation controller driver
  6 *
  7 * Copyright (c) 2010-2020, NVIDIA Corporation.
  8 * Based on arch/arm/plat-mxc/pwm.c by Sascha Hauer <s.hauer@pengutronix.de>
  9 *
 10 * Overview of Tegra Pulse Width Modulator Register:
 11 * 1. 13-bit: Frequency division (SCALE)
 12 * 2. 8-bit : Pulse division (DUTY)
 13 * 3. 1-bit : Enable bit
 14 *
 15 * The PWM clock frequency is divided by 256 before subdividing it based
 16 * on the programmable frequency division value to generate the required
 17 * frequency for PWM output. The maximum output frequency that can be
 18 * achieved is (max rate of source clock) / 256.
 19 * e.g. if source clock rate is 408 MHz, maximum output frequency can be:
 20 * 408 MHz/256 = 1.6 MHz.
 21 * This 1.6 MHz frequency can further be divided using SCALE value in PWM.
 22 *
 23 * PWM pulse width: 8 bits are usable [23:16] for varying pulse width.
 24 * To achieve 100% duty cycle, program Bit [24] of this register to
 25 * 1’b1. In which case the other bits [23:16] are set to don't care.
 26 *
 27 * Limitations:
 28 * -	When PWM is disabled, the output is driven to inactive.
 29 * -	It does not allow the current PWM period to complete and
 30 *	stops abruptly.
 31 *
 32 * -	If the register is reconfigured while PWM is running,
 33 *	it does not complete the currently running period.
 34 *
 35 * -	If the user input duty is beyond acceptible limits,
 36 *	-EINVAL is returned.
 37 */
 38
 39#include <linux/clk.h>
 40#include <linux/err.h>
 41#include <linux/io.h>
 42#include <linux/module.h>
 43#include <linux/of.h>
 44#include <linux/pm_opp.h>
 45#include <linux/pwm.h>
 46#include <linux/platform_device.h>
 47#include <linux/pinctrl/consumer.h>
 48#include <linux/pm_runtime.h>
 49#include <linux/slab.h>
 50#include <linux/reset.h>
 51
 52#include <soc/tegra/common.h>
 53
 54#define PWM_ENABLE	(1 << 31)
 55#define PWM_DUTY_WIDTH	8
 56#define PWM_DUTY_SHIFT	16
 57#define PWM_SCALE_WIDTH	13
 58#define PWM_SCALE_SHIFT	0
 59
 60struct tegra_pwm_soc {
 61	unsigned int num_channels;
 62
 63	/* Maximum IP frequency for given SoCs */
 64	unsigned long max_frequency;
 65};
 66
 67struct tegra_pwm_chip {
 
 
 
 68	struct clk *clk;
 69	struct reset_control*rst;
 70
 71	unsigned long clk_rate;
 72	unsigned long min_period_ns;
 73
 74	void __iomem *regs;
 75
 76	const struct tegra_pwm_soc *soc;
 77};
 78
 79static inline struct tegra_pwm_chip *to_tegra_pwm_chip(struct pwm_chip *chip)
 80{
 81	return pwmchip_get_drvdata(chip);
 82}
 83
 84static inline u32 pwm_readl(struct tegra_pwm_chip *pc, unsigned int offset)
 85{
 86	return readl(pc->regs + (offset << 4));
 87}
 88
 89static inline void pwm_writel(struct tegra_pwm_chip *pc, unsigned int offset, u32 value)
 
 90{
 91	writel(value, pc->regs + (offset << 4));
 92}
 93
 94static int tegra_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 95			    int duty_ns, int period_ns)
 96{
 97	struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
 98	unsigned long long c = duty_ns;
 99	unsigned long rate, required_clk_rate;
100	u32 val = 0;
101	int err;
102
103	/*
104	 * Convert from duty_ns / period_ns to a fixed number of duty ticks
105	 * per (1 << PWM_DUTY_WIDTH) cycles and make sure to round to the
106	 * nearest integer during division.
107	 */
108	c *= (1 << PWM_DUTY_WIDTH);
109	c = DIV_ROUND_CLOSEST_ULL(c, period_ns);
110
111	val = (u32)c << PWM_DUTY_SHIFT;
112
113	/*
114	 *  min period = max clock limit >> PWM_DUTY_WIDTH
115	 */
116	if (period_ns < pc->min_period_ns)
117		return -EINVAL;
118
119	/*
120	 * Compute the prescaler value for which (1 << PWM_DUTY_WIDTH)
121	 * cycles at the PWM clock rate will take period_ns nanoseconds.
122	 *
123	 * num_channels: If single instance of PWM controller has multiple
124	 * channels (e.g. Tegra210 or older) then it is not possible to
125	 * configure separate clock rates to each of the channels, in such
126	 * case the value stored during probe will be referred.
127	 *
128	 * If every PWM controller instance has one channel respectively, i.e.
129	 * nums_channels == 1 then only the clock rate can be modified
130	 * dynamically (e.g. Tegra186 or Tegra194).
131	 */
132	if (pc->soc->num_channels == 1) {
133		/*
134		 * Rate is multiplied with 2^PWM_DUTY_WIDTH so that it matches
135		 * with the maximum possible rate that the controller can
136		 * provide. Any further lower value can be derived by setting
137		 * PFM bits[0:12].
138		 *
139		 * required_clk_rate is a reference rate for source clock and
140		 * it is derived based on user requested period. By setting the
141		 * source clock rate as required_clk_rate, PWM controller will
142		 * be able to configure the requested period.
143		 */
144		required_clk_rate = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC << PWM_DUTY_WIDTH,
145						     period_ns);
146
147		if (required_clk_rate > clk_round_rate(pc->clk, required_clk_rate))
148			/*
149			 * required_clk_rate is a lower bound for the input
150			 * rate; for lower rates there is no value for PWM_SCALE
151			 * that yields a period less than or equal to the
152			 * requested period. Hence, for lower rates, double the
153			 * required_clk_rate to get a clock rate that can meet
154			 * the requested period.
155			 */
156			required_clk_rate *= 2;
157
158		err = dev_pm_opp_set_rate(pwmchip_parent(chip), required_clk_rate);
159		if (err < 0)
160			return -EINVAL;
161
162		/* Store the new rate for further references */
163		pc->clk_rate = clk_get_rate(pc->clk);
164	}
165
166	/* Consider precision in PWM_SCALE_WIDTH rate calculation */
167	rate = mul_u64_u64_div_u64(pc->clk_rate, period_ns,
168				   (u64)NSEC_PER_SEC << PWM_DUTY_WIDTH);
169
170	/*
171	 * Since the actual PWM divider is the register's frequency divider
172	 * field plus 1, we need to decrement to get the correct value to
173	 * write to the register.
174	 */
175	if (rate > 0)
176		rate--;
177	else
178		return -EINVAL;
179
180	/*
181	 * Make sure that the rate will fit in the register's frequency
182	 * divider field.
183	 */
184	if (rate >> PWM_SCALE_WIDTH)
185		return -EINVAL;
186
187	val |= rate << PWM_SCALE_SHIFT;
188
189	/*
190	 * If the PWM channel is disabled, make sure to turn on the clock
191	 * before writing the register. Otherwise, keep it enabled.
192	 */
193	if (!pwm_is_enabled(pwm)) {
194		err = pm_runtime_resume_and_get(pwmchip_parent(chip));
195		if (err)
196			return err;
197	} else
198		val |= PWM_ENABLE;
199
200	pwm_writel(pc, pwm->hwpwm, val);
201
202	/*
203	 * If the PWM is not enabled, turn the clock off again to save power.
204	 */
205	if (!pwm_is_enabled(pwm))
206		pm_runtime_put(pwmchip_parent(chip));
207
208	return 0;
209}
210
211static int tegra_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
212{
213	struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
214	int rc = 0;
215	u32 val;
216
217	rc = pm_runtime_resume_and_get(pwmchip_parent(chip));
218	if (rc)
219		return rc;
220
221	val = pwm_readl(pc, pwm->hwpwm);
222	val |= PWM_ENABLE;
223	pwm_writel(pc, pwm->hwpwm, val);
224
225	return 0;
226}
227
228static void tegra_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
229{
230	struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
231	u32 val;
232
233	val = pwm_readl(pc, pwm->hwpwm);
234	val &= ~PWM_ENABLE;
235	pwm_writel(pc, pwm->hwpwm, val);
236
237	pm_runtime_put_sync(pwmchip_parent(chip));
238}
239
240static int tegra_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
241			   const struct pwm_state *state)
242{
243	int err;
244	bool enabled = pwm->state.enabled;
245
246	if (state->polarity != PWM_POLARITY_NORMAL)
247		return -EINVAL;
248
249	if (!state->enabled) {
250		if (enabled)
251			tegra_pwm_disable(chip, pwm);
252
253		return 0;
254	}
255
256	err = tegra_pwm_config(chip, pwm, state->duty_cycle, state->period);
257	if (err)
258		return err;
259
260	if (!enabled)
261		err = tegra_pwm_enable(chip, pwm);
262
263	return err;
264}
265
266static const struct pwm_ops tegra_pwm_ops = {
267	.apply = tegra_pwm_apply,
 
 
 
268};
269
270static int tegra_pwm_probe(struct platform_device *pdev)
271{
272	struct pwm_chip *chip;
273	struct tegra_pwm_chip *pc;
274	const struct tegra_pwm_soc *soc;
275	int ret;
276
277	soc = of_device_get_match_data(&pdev->dev);
278
279	chip = devm_pwmchip_alloc(&pdev->dev, soc->num_channels, sizeof(*pc));
280	if (IS_ERR(chip))
281		return PTR_ERR(chip);
282	pc = to_tegra_pwm_chip(chip);
283
284	pc->soc = soc;
285
286	pc->regs = devm_platform_ioremap_resource(pdev, 0);
287	if (IS_ERR(pc->regs))
288		return PTR_ERR(pc->regs);
289
290	platform_set_drvdata(pdev, chip);
291
292	pc->clk = devm_clk_get(&pdev->dev, NULL);
293	if (IS_ERR(pc->clk))
294		return PTR_ERR(pc->clk);
295
296	ret = devm_tegra_core_dev_init_opp_table_common(&pdev->dev);
297	if (ret)
298		return ret;
299
300	pm_runtime_enable(&pdev->dev);
301	ret = pm_runtime_resume_and_get(&pdev->dev);
302	if (ret)
303		return ret;
304
305	/* Set maximum frequency of the IP */
306	ret = dev_pm_opp_set_rate(&pdev->dev, pc->soc->max_frequency);
307	if (ret < 0) {
308		dev_err(&pdev->dev, "Failed to set max frequency: %d\n", ret);
309		goto put_pm;
310	}
311
312	/*
313	 * The requested and configured frequency may differ due to
314	 * clock register resolutions. Get the configured frequency
315	 * so that PWM period can be calculated more accurately.
316	 */
317	pc->clk_rate = clk_get_rate(pc->clk);
318
319	/* Set minimum limit of PWM period for the IP */
320	pc->min_period_ns =
321	    (NSEC_PER_SEC / (pc->soc->max_frequency >> PWM_DUTY_WIDTH)) + 1;
322
323	pc->rst = devm_reset_control_get_exclusive(&pdev->dev, "pwm");
324	if (IS_ERR(pc->rst)) {
325		ret = PTR_ERR(pc->rst);
326		dev_err(&pdev->dev, "Reset control is not found: %d\n", ret);
327		goto put_pm;
328	}
329
330	reset_control_deassert(pc->rst);
331
332	chip->ops = &tegra_pwm_ops;
 
 
 
333
334	ret = pwmchip_add(chip);
335	if (ret < 0) {
336		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
337		reset_control_assert(pc->rst);
338		goto put_pm;
339	}
340
341	pm_runtime_put(&pdev->dev);
342
343	return 0;
344put_pm:
345	pm_runtime_put_sync_suspend(&pdev->dev);
346	pm_runtime_force_suspend(&pdev->dev);
347	return ret;
348}
349
350static void tegra_pwm_remove(struct platform_device *pdev)
351{
352	struct pwm_chip *chip = platform_get_drvdata(pdev);
353	struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
 
354
355	pwmchip_remove(chip);
 
356
357	reset_control_assert(pc->rst);
 
 
358
359	pm_runtime_force_suspend(&pdev->dev);
360}
361
362static int __maybe_unused tegra_pwm_runtime_suspend(struct device *dev)
363{
364	struct pwm_chip *chip = dev_get_drvdata(dev);
365	struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
366	int err;
367
368	clk_disable_unprepare(pc->clk);
369
370	err = pinctrl_pm_select_sleep_state(dev);
371	if (err) {
372		clk_prepare_enable(pc->clk);
373		return err;
374	}
375
376	return 0;
 
 
 
377}
378
379static int __maybe_unused tegra_pwm_runtime_resume(struct device *dev)
 
380{
381	struct pwm_chip *chip = dev_get_drvdata(dev);
382	struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
383	int err;
384
385	err = pinctrl_pm_select_default_state(dev);
386	if (err)
387		return err;
388
389	err = clk_prepare_enable(pc->clk);
390	if (err) {
391		pinctrl_pm_select_sleep_state(dev);
392		return err;
393	}
394
395	return 0;
 
 
396}
 
397
398static const struct tegra_pwm_soc tegra20_pwm_soc = {
399	.num_channels = 4,
400	.max_frequency = 48000000UL,
401};
402
403static const struct tegra_pwm_soc tegra186_pwm_soc = {
404	.num_channels = 1,
405	.max_frequency = 102000000UL,
406};
407
408static const struct tegra_pwm_soc tegra194_pwm_soc = {
409	.num_channels = 1,
410	.max_frequency = 408000000UL,
411};
412
413static const struct of_device_id tegra_pwm_of_match[] = {
414	{ .compatible = "nvidia,tegra20-pwm", .data = &tegra20_pwm_soc },
415	{ .compatible = "nvidia,tegra186-pwm", .data = &tegra186_pwm_soc },
416	{ .compatible = "nvidia,tegra194-pwm", .data = &tegra194_pwm_soc },
417	{ }
418};
 
419MODULE_DEVICE_TABLE(of, tegra_pwm_of_match);
420
421static const struct dev_pm_ops tegra_pwm_pm_ops = {
422	SET_RUNTIME_PM_OPS(tegra_pwm_runtime_suspend, tegra_pwm_runtime_resume,
423			   NULL)
424	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
425				pm_runtime_force_resume)
426};
427
428static struct platform_driver tegra_pwm_driver = {
429	.driver = {
430		.name = "tegra-pwm",
431		.of_match_table = tegra_pwm_of_match,
432		.pm = &tegra_pwm_pm_ops,
433	},
434	.probe = tegra_pwm_probe,
435	.remove = tegra_pwm_remove,
436};
437
438module_platform_driver(tegra_pwm_driver);
439
440MODULE_LICENSE("GPL");
441MODULE_AUTHOR("Sandipan Patra <spatra@nvidia.com>");
442MODULE_DESCRIPTION("Tegra PWM controller driver");
443MODULE_ALIAS("platform:tegra-pwm");
v4.17
 
  1/*
  2 * drivers/pwm/pwm-tegra.c
  3 *
  4 * Tegra pulse-width-modulation controller driver
  5 *
  6 * Copyright (c) 2010, NVIDIA Corporation.
  7 * Based on arch/arm/plat-mxc/pwm.c by Sascha Hauer <s.hauer@pengutronix.de>
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License as published by
 11 * the Free Software Foundation; either version 2 of the License, or
 12 * (at your option) any later version.
 13 *
 14 * This program is distributed in the hope that it will be useful, but WITHOUT
 15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 16 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 17 * more details.
 
 
 
 18 *
 19 * You should have received a copy of the GNU General Public License along
 20 * with this program; if not, write to the Free Software Foundation, Inc.,
 21 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 
 
 
 
 
 
 
 
 
 
 22 */
 23
 24#include <linux/clk.h>
 25#include <linux/err.h>
 26#include <linux/io.h>
 27#include <linux/module.h>
 28#include <linux/of.h>
 29#include <linux/of_device.h>
 30#include <linux/pwm.h>
 31#include <linux/platform_device.h>
 32#include <linux/pinctrl/consumer.h>
 
 33#include <linux/slab.h>
 34#include <linux/reset.h>
 35
 
 
 36#define PWM_ENABLE	(1 << 31)
 37#define PWM_DUTY_WIDTH	8
 38#define PWM_DUTY_SHIFT	16
 39#define PWM_SCALE_WIDTH	13
 40#define PWM_SCALE_SHIFT	0
 41
 42struct tegra_pwm_soc {
 43	unsigned int num_channels;
 44
 45	/* Maximum IP frequency for given SoCs */
 46	unsigned long max_frequency;
 47};
 48
 49struct tegra_pwm_chip {
 50	struct pwm_chip chip;
 51	struct device *dev;
 52
 53	struct clk *clk;
 54	struct reset_control*rst;
 55
 56	unsigned long clk_rate;
 
 57
 58	void __iomem *regs;
 59
 60	const struct tegra_pwm_soc *soc;
 61};
 62
 63static inline struct tegra_pwm_chip *to_tegra_pwm_chip(struct pwm_chip *chip)
 64{
 65	return container_of(chip, struct tegra_pwm_chip, chip);
 66}
 67
 68static inline u32 pwm_readl(struct tegra_pwm_chip *chip, unsigned int num)
 69{
 70	return readl(chip->regs + (num << 4));
 71}
 72
 73static inline void pwm_writel(struct tegra_pwm_chip *chip, unsigned int num,
 74			     unsigned long val)
 75{
 76	writel(val, chip->regs + (num << 4));
 77}
 78
 79static int tegra_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 80			    int duty_ns, int period_ns)
 81{
 82	struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
 83	unsigned long long c = duty_ns, hz;
 84	unsigned long rate;
 85	u32 val = 0;
 86	int err;
 87
 88	/*
 89	 * Convert from duty_ns / period_ns to a fixed number of duty ticks
 90	 * per (1 << PWM_DUTY_WIDTH) cycles and make sure to round to the
 91	 * nearest integer during division.
 92	 */
 93	c *= (1 << PWM_DUTY_WIDTH);
 94	c = DIV_ROUND_CLOSEST_ULL(c, period_ns);
 95
 96	val = (u32)c << PWM_DUTY_SHIFT;
 97
 98	/*
 
 
 
 
 
 
 99	 * Compute the prescaler value for which (1 << PWM_DUTY_WIDTH)
100	 * cycles at the PWM clock rate will take period_ns nanoseconds.
 
 
 
 
 
 
 
 
 
101	 */
102	rate = pc->clk_rate >> PWM_DUTY_WIDTH;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
103
104	/* Consider precision in PWM_SCALE_WIDTH rate calculation */
105	hz = DIV_ROUND_CLOSEST_ULL(100ULL * NSEC_PER_SEC, period_ns);
106	rate = DIV_ROUND_CLOSEST_ULL(100ULL * rate, hz);
107
108	/*
109	 * Since the actual PWM divider is the register's frequency divider
110	 * field minus 1, we need to decrement to get the correct value to
111	 * write to the register.
112	 */
113	if (rate > 0)
114		rate--;
 
 
115
116	/*
117	 * Make sure that the rate will fit in the register's frequency
118	 * divider field.
119	 */
120	if (rate >> PWM_SCALE_WIDTH)
121		return -EINVAL;
122
123	val |= rate << PWM_SCALE_SHIFT;
124
125	/*
126	 * If the PWM channel is disabled, make sure to turn on the clock
127	 * before writing the register. Otherwise, keep it enabled.
128	 */
129	if (!pwm_is_enabled(pwm)) {
130		err = clk_prepare_enable(pc->clk);
131		if (err < 0)
132			return err;
133	} else
134		val |= PWM_ENABLE;
135
136	pwm_writel(pc, pwm->hwpwm, val);
137
138	/*
139	 * If the PWM is not enabled, turn the clock off again to save power.
140	 */
141	if (!pwm_is_enabled(pwm))
142		clk_disable_unprepare(pc->clk);
143
144	return 0;
145}
146
147static int tegra_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
148{
149	struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
150	int rc = 0;
151	u32 val;
152
153	rc = clk_prepare_enable(pc->clk);
154	if (rc < 0)
155		return rc;
156
157	val = pwm_readl(pc, pwm->hwpwm);
158	val |= PWM_ENABLE;
159	pwm_writel(pc, pwm->hwpwm, val);
160
161	return 0;
162}
163
164static void tegra_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
165{
166	struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
167	u32 val;
168
169	val = pwm_readl(pc, pwm->hwpwm);
170	val &= ~PWM_ENABLE;
171	pwm_writel(pc, pwm->hwpwm, val);
172
173	clk_disable_unprepare(pc->clk);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
174}
175
176static const struct pwm_ops tegra_pwm_ops = {
177	.config = tegra_pwm_config,
178	.enable = tegra_pwm_enable,
179	.disable = tegra_pwm_disable,
180	.owner = THIS_MODULE,
181};
182
183static int tegra_pwm_probe(struct platform_device *pdev)
184{
185	struct tegra_pwm_chip *pwm;
186	struct resource *r;
 
187	int ret;
188
189	pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
190	if (!pwm)
191		return -ENOMEM;
192
193	pwm->soc = of_device_get_match_data(&pdev->dev);
194	pwm->dev = &pdev->dev;
195
196	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
197	pwm->regs = devm_ioremap_resource(&pdev->dev, r);
198	if (IS_ERR(pwm->regs))
199		return PTR_ERR(pwm->regs);
200
201	platform_set_drvdata(pdev, pwm);
202
203	pwm->clk = devm_clk_get(&pdev->dev, NULL);
204	if (IS_ERR(pwm->clk))
205		return PTR_ERR(pwm->clk);
 
 
 
 
 
 
 
 
 
 
206
207	/* Set maximum frequency of the IP */
208	ret = clk_set_rate(pwm->clk, pwm->soc->max_frequency);
209	if (ret < 0) {
210		dev_err(&pdev->dev, "Failed to set max frequency: %d\n", ret);
211		return ret;
212	}
213
214	/*
215	 * The requested and configured frequency may differ due to
216	 * clock register resolutions. Get the configured frequency
217	 * so that PWM period can be calculated more accurately.
218	 */
219	pwm->clk_rate = clk_get_rate(pwm->clk);
220
221	pwm->rst = devm_reset_control_get_exclusive(&pdev->dev, "pwm");
222	if (IS_ERR(pwm->rst)) {
223		ret = PTR_ERR(pwm->rst);
 
 
 
 
224		dev_err(&pdev->dev, "Reset control is not found: %d\n", ret);
225		return ret;
226	}
227
228	reset_control_deassert(pwm->rst);
229
230	pwm->chip.dev = &pdev->dev;
231	pwm->chip.ops = &tegra_pwm_ops;
232	pwm->chip.base = -1;
233	pwm->chip.npwm = pwm->soc->num_channels;
234
235	ret = pwmchip_add(&pwm->chip);
236	if (ret < 0) {
237		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
238		reset_control_assert(pwm->rst);
239		return ret;
240	}
241
 
 
242	return 0;
 
 
 
 
243}
244
245static int tegra_pwm_remove(struct platform_device *pdev)
246{
247	struct tegra_pwm_chip *pc = platform_get_drvdata(pdev);
248	unsigned int i;
249	int err;
250
251	if (WARN_ON(!pc))
252		return -ENODEV;
253
254	err = clk_prepare_enable(pc->clk);
255	if (err < 0)
256		return err;
257
258	for (i = 0; i < pc->chip.npwm; i++) {
259		struct pwm_device *pwm = &pc->chip.pwms[i];
260
261		if (!pwm_is_enabled(pwm))
262			if (clk_prepare_enable(pc->clk) < 0)
263				continue;
 
 
264
265		pwm_writel(pc, i, 0);
266
267		clk_disable_unprepare(pc->clk);
 
 
 
268	}
269
270	reset_control_assert(pc->rst);
271	clk_disable_unprepare(pc->clk);
272
273	return pwmchip_remove(&pc->chip);
274}
275
276#ifdef CONFIG_PM_SLEEP
277static int tegra_pwm_suspend(struct device *dev)
278{
279	return pinctrl_pm_select_sleep_state(dev);
280}
 
 
 
 
 
 
 
 
 
 
 
281
282static int tegra_pwm_resume(struct device *dev)
283{
284	return pinctrl_pm_select_default_state(dev);
285}
286#endif
287
288static const struct tegra_pwm_soc tegra20_pwm_soc = {
289	.num_channels = 4,
290	.max_frequency = 48000000UL,
291};
292
293static const struct tegra_pwm_soc tegra186_pwm_soc = {
294	.num_channels = 1,
295	.max_frequency = 102000000UL,
296};
297
 
 
 
 
 
298static const struct of_device_id tegra_pwm_of_match[] = {
299	{ .compatible = "nvidia,tegra20-pwm", .data = &tegra20_pwm_soc },
300	{ .compatible = "nvidia,tegra186-pwm", .data = &tegra186_pwm_soc },
 
301	{ }
302};
303
304MODULE_DEVICE_TABLE(of, tegra_pwm_of_match);
305
306static const struct dev_pm_ops tegra_pwm_pm_ops = {
307	SET_SYSTEM_SLEEP_PM_OPS(tegra_pwm_suspend, tegra_pwm_resume)
 
 
 
308};
309
310static struct platform_driver tegra_pwm_driver = {
311	.driver = {
312		.name = "tegra-pwm",
313		.of_match_table = tegra_pwm_of_match,
314		.pm = &tegra_pwm_pm_ops,
315	},
316	.probe = tegra_pwm_probe,
317	.remove = tegra_pwm_remove,
318};
319
320module_platform_driver(tegra_pwm_driver);
321
322MODULE_LICENSE("GPL");
323MODULE_AUTHOR("NVIDIA Corporation");
 
324MODULE_ALIAS("platform:tegra-pwm");