[linux.git] / drivers / pwm / pwm-dwc.c

// SPDX-License-Identifier: GPL-2.0
/*
 * DesignWare PWM Controller driver
 *
 * Copyright (C) 2018-2020 Intel Corporation
 *
 * Author: Felipe Balbi (Intel)
 * Author: Jarkko Nikula <[email protected]>
 * Author: Raymond Tan <[email protected]>
 *
 * Limitations:
 * - The hardware cannot generate a 0 % or 100 % duty cycle. Both high and low
 *   periods are one or more input clock periods long.
 */

#include <linux/bitops.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pm_runtime.h>
#include <linux/pwm.h>

#define DWC_TIM_LD_CNT(n)	((n) * 0x14)
#define DWC_TIM_LD_CNT2(n)	(((n) * 4) + 0xb0)
#define DWC_TIM_CUR_VAL(n)	(((n) * 0x14) + 0x04)
#define DWC_TIM_CTRL(n)		(((n) * 0x14) + 0x08)
#define DWC_TIM_EOI(n)		(((n) * 0x14) + 0x0c)
#define DWC_TIM_INT_STS(n)	(((n) * 0x14) + 0x10)

#define DWC_TIMERS_INT_STS	0xa0
#define DWC_TIMERS_EOI		0xa4
#define DWC_TIMERS_RAW_INT_STS	0xa8
#define DWC_TIMERS_COMP_VERSION	0xac

#define DWC_TIMERS_TOTAL	8
#define DWC_CLK_PERIOD_NS	10

/* Timer Control Register */
#define DWC_TIM_CTRL_EN		BIT(0)
#define DWC_TIM_CTRL_MODE	BIT(1)
#define DWC_TIM_CTRL_MODE_FREE	(0 << 1)
#define DWC_TIM_CTRL_MODE_USER	(1 << 1)
#define DWC_TIM_CTRL_INT_MASK	BIT(2)
#define DWC_TIM_CTRL_PWM	BIT(3)

struct dwc_pwm_ctx {
	u32 cnt;
	u32 cnt2;
	u32 ctrl;
};

struct dwc_pwm {
	struct pwm_chip chip;
	void __iomem *base;
	struct dwc_pwm_ctx ctx[DWC_TIMERS_TOTAL];
};
#define to_dwc_pwm(p)	(container_of((p), struct dwc_pwm, chip))

static inline u32 dwc_pwm_readl(struct dwc_pwm *dwc, u32 offset)
{
	return readl(dwc->base + offset);
}

static inline void dwc_pwm_writel(struct dwc_pwm *dwc, u32 value, u32 offset)
{
	writel(value, dwc->base + offset);
}

static void __dwc_pwm_set_enable(struct dwc_pwm *dwc, int pwm, int enabled)
{
	u32 reg;

	reg = dwc_pwm_readl(dwc, DWC_TIM_CTRL(pwm));

	if (enabled)
		reg |= DWC_TIM_CTRL_EN;
	else
		reg &= ~DWC_TIM_CTRL_EN;

	dwc_pwm_writel(dwc, reg, DWC_TIM_CTRL(pwm));
}

static int __dwc_pwm_configure_timer(struct dwc_pwm *dwc,
				     struct pwm_device *pwm,
				     const struct pwm_state *state)
{
	u64 tmp;
	u32 ctrl;
	u32 high;
	u32 low;

	/*
	 * Calculate width of low and high period in terms of input clock
	 * periods and check are the result within HW limits between 1 and
	 * 2^32 periods.
	 */
	tmp = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, DWC_CLK_PERIOD_NS);
	if (tmp < 1 || tmp > (1ULL << 32))
		return -ERANGE;
	low = tmp - 1;

	tmp = DIV_ROUND_CLOSEST_ULL(state->period - state->duty_cycle,
				    DWC_CLK_PERIOD_NS);
	if (tmp < 1 || tmp > (1ULL << 32))
		return -ERANGE;
	high = tmp - 1;

	/*
	 * Specification says timer usage flow is to disable timer, then
	 * program it followed by enable. It also says Load Count is loaded
	 * into timer after it is enabled - either after a disable or
	 * a reset. Based on measurements it happens also without disable
	 * whenever Load Count is updated. But follow the specification.
	 */
	__dwc_pwm_set_enable(dwc, pwm->hwpwm, false);

	/*
	 * Write Load Count and Load Count 2 registers. Former defines the
	 * width of low period and latter the width of high period in terms
	 * multiple of input clock periods:
	 * Width = ((Count + 1) * input clock period).
	 */
	dwc_pwm_writel(dwc, low, DWC_TIM_LD_CNT(pwm->hwpwm));
	dwc_pwm_writel(dwc, high, DWC_TIM_LD_CNT2(pwm->hwpwm));

	/*
	 * Set user-defined mode, timer reloads from Load Count registers
	 * when it counts down to 0.
	 * Set PWM mode, it makes output to toggle and width of low and high
	 * periods are set by Load Count registers.
	 */
	ctrl = DWC_TIM_CTRL_MODE_USER | DWC_TIM_CTRL_PWM;
	dwc_pwm_writel(dwc, ctrl, DWC_TIM_CTRL(pwm->hwpwm));

	/*
	 * Enable timer. Output starts from low period.
	 */
	__dwc_pwm_set_enable(dwc, pwm->hwpwm, state->enabled);

	return 0;
}

static int dwc_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
			 const struct pwm_state *state)
{
	struct dwc_pwm *dwc = to_dwc_pwm(chip);

	if (state->polarity != PWM_POLARITY_INVERSED)
		return -EINVAL;

	if (state->enabled) {
		if (!pwm->state.enabled)
			pm_runtime_get_sync(chip->dev);
		return __dwc_pwm_configure_timer(dwc, pwm, state);
	} else {
		if (pwm->state.enabled) {
			__dwc_pwm_set_enable(dwc, pwm->hwpwm, false);
			pm_runtime_put_sync(chip->dev);
		}
	}

	return 0;
}

static void dwc_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
			      struct pwm_state *state)
{
	struct dwc_pwm *dwc = to_dwc_pwm(chip);
	u64 duty, period;

	pm_runtime_get_sync(chip->dev);

	state->enabled = !!(dwc_pwm_readl(dwc,
				DWC_TIM_CTRL(pwm->hwpwm)) & DWC_TIM_CTRL_EN);

	duty = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(pwm->hwpwm));
	duty += 1;
	duty *= DWC_CLK_PERIOD_NS;
	state->duty_cycle = duty;

	period = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(pwm->hwpwm));
	period += 1;
	period *= DWC_CLK_PERIOD_NS;
	period += duty;
	state->period = period;

	state->polarity = PWM_POLARITY_INVERSED;

	pm_runtime_put_sync(chip->dev);
}

static const struct pwm_ops dwc_pwm_ops = {
	.apply = dwc_pwm_apply,
	.get_state = dwc_pwm_get_state,
	.owner = THIS_MODULE,
};

static int dwc_pwm_probe(struct pci_dev *pci, const struct pci_device_id *id)
{
	struct device *dev = &pci->dev;
	struct dwc_pwm *dwc;
	int ret;

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

	ret = pcim_enable_device(pci);
	if (ret) {
		dev_err(&pci->dev,
			"Failed to enable device (%pe)\n", ERR_PTR(ret));
		return ret;
	}

	pci_set_master(pci);

	ret = pcim_iomap_regions(pci, BIT(0), pci_name(pci));
	if (ret) {
		dev_err(&pci->dev,
			"Failed to iomap PCI BAR (%pe)\n", ERR_PTR(ret));
		return ret;
	}

	dwc->base = pcim_iomap_table(pci)[0];
	if (!dwc->base) {
		dev_err(&pci->dev, "Base address missing\n");
		return -ENOMEM;
	}

	pci_set_drvdata(pci, dwc);

	dwc->chip.dev = dev;
	dwc->chip.ops = &dwc_pwm_ops;
	dwc->chip.npwm = DWC_TIMERS_TOTAL;

	ret = pwmchip_add(&dwc->chip);
	if (ret)
		return ret;

	pm_runtime_put(dev);
	pm_runtime_allow(dev);

	return 0;
}

static void dwc_pwm_remove(struct pci_dev *pci)
{
	struct dwc_pwm *dwc = pci_get_drvdata(pci);

	pm_runtime_forbid(&pci->dev);
	pm_runtime_get_noresume(&pci->dev);

	pwmchip_remove(&dwc->chip);
}

#ifdef CONFIG_PM_SLEEP
static int dwc_pwm_suspend(struct device *dev)
{
	struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
	struct dwc_pwm *dwc = pci_get_drvdata(pdev);
	int i;

	for (i = 0; i < DWC_TIMERS_TOTAL; i++) {
		if (dwc->chip.pwms[i].state.enabled) {
			dev_err(dev, "PWM %u in use by consumer (%s)\n",
				i, dwc->chip.pwms[i].label);
			return -EBUSY;
		}
		dwc->ctx[i].cnt = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(i));
		dwc->ctx[i].cnt2 = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(i));
		dwc->ctx[i].ctrl = dwc_pwm_readl(dwc, DWC_TIM_CTRL(i));
	}

	return 0;
}

static int dwc_pwm_resume(struct device *dev)
{
	struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
	struct dwc_pwm *dwc = pci_get_drvdata(pdev);
	int i;

	for (i = 0; i < DWC_TIMERS_TOTAL; i++) {
		dwc_pwm_writel(dwc, dwc->ctx[i].cnt, DWC_TIM_LD_CNT(i));
		dwc_pwm_writel(dwc, dwc->ctx[i].cnt2, DWC_TIM_LD_CNT2(i));
		dwc_pwm_writel(dwc, dwc->ctx[i].ctrl, DWC_TIM_CTRL(i));
	}

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(dwc_pwm_pm_ops, dwc_pwm_suspend, dwc_pwm_resume);

static const struct pci_device_id dwc_pwm_id_table[] = {
	{ PCI_VDEVICE(INTEL, 0x4bb7) }, /* Elkhart Lake */
	{  }	/* Terminating Entry */
};
MODULE_DEVICE_TABLE(pci, dwc_pwm_id_table);

static struct pci_driver dwc_pwm_driver = {
	.name = "pwm-dwc",
	.probe = dwc_pwm_probe,
	.remove = dwc_pwm_remove,
	.id_table = dwc_pwm_id_table,
	.driver = {
		.pm = &dwc_pwm_pm_ops,
	},
};

module_pci_driver(dwc_pwm_driver);

MODULE_AUTHOR("Felipe Balbi (Intel)");
MODULE_AUTHOR("Jarkko Nikula <[email protected]>");
MODULE_AUTHOR("Raymond Tan <[email protected]>");
MODULE_DESCRIPTION("DesignWare PWM Controller");
MODULE_LICENSE("GPL");
Commit	Line	Data
1ed2b3fc JN	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* DesignWare PWM Controller driver
	4	*
	5	* Copyright (C) 2018-2020 Intel Corporation
	6	*
	7	* Author: Felipe Balbi (Intel)
	8	* Author: Jarkko Nikula <[email protected]>
	9	* Author: Raymond Tan <[email protected]>
	10	*
	11	* Limitations:
	12	* - The hardware cannot generate a 0 % or 100 % duty cycle. Both high and low
	13	* periods are one or more input clock periods long.
	14	*/
	15
	16	#include <linux/bitops.h>
	17	#include <linux/export.h>
	18	#include <linux/kernel.h>
	19	#include <linux/module.h>
	20	#include <linux/pci.h>
	21	#include <linux/pm_runtime.h>
	22	#include <linux/pwm.h>
	23
	24	#define DWC_TIM_LD_CNT(n) ((n) * 0x14)
	25	#define DWC_TIM_LD_CNT2(n) (((n) * 4) + 0xb0)
	26	#define DWC_TIM_CUR_VAL(n) (((n) * 0x14) + 0x04)
	27	#define DWC_TIM_CTRL(n) (((n) * 0x14) + 0x08)
	28	#define DWC_TIM_EOI(n) (((n) * 0x14) + 0x0c)
	29	#define DWC_TIM_INT_STS(n) (((n) * 0x14) + 0x10)
	30
	31	#define DWC_TIMERS_INT_STS 0xa0
	32	#define DWC_TIMERS_EOI 0xa4
	33	#define DWC_TIMERS_RAW_INT_STS 0xa8
	34	#define DWC_TIMERS_COMP_VERSION 0xac
	35
	36	#define DWC_TIMERS_TOTAL 8
	37	#define DWC_CLK_PERIOD_NS 10
	38
	39	/* Timer Control Register */
	40	#define DWC_TIM_CTRL_EN BIT(0)
	41	#define DWC_TIM_CTRL_MODE BIT(1)
	42	#define DWC_TIM_CTRL_MODE_FREE (0 << 1)
	43	#define DWC_TIM_CTRL_MODE_USER (1 << 1)
	44	#define DWC_TIM_CTRL_INT_MASK BIT(2)
	45	#define DWC_TIM_CTRL_PWM BIT(3)
	46
	47	struct dwc_pwm_ctx {
	48	u32 cnt;
	49	u32 cnt2;
	50	u32 ctrl;
	51	};
	52
	53	struct dwc_pwm {
	54	struct pwm_chip chip;
	55	void __iomem *base;
	56	struct dwc_pwm_ctx ctx[DWC_TIMERS_TOTAL];
	57	};
	58	#define to_dwc_pwm(p) (container_of((p), struct dwc_pwm, chip))
	59
	60	static inline u32 dwc_pwm_readl(struct dwc_pwm *dwc, u32 offset)
	61	{
	62	return readl(dwc->base + offset);
	63	}
	64
65	static inline void dwc_pwm_writel(struct dwc_pwm *dwc, u32 value, u32 offset)
66	{
67	writel(value, dwc->base + offset);
68	}
69
70	static void __dwc_pwm_set_enable(struct dwc_pwm *dwc, int pwm, int enabled)
71	{
72	u32 reg;
73
74	reg = dwc_pwm_readl(dwc, DWC_TIM_CTRL(pwm));
75
76	if (enabled)
77	reg \|= DWC_TIM_CTRL_EN;
78	else
79	reg &= ~DWC_TIM_CTRL_EN;
80
81	dwc_pwm_writel(dwc, reg, DWC_TIM_CTRL(pwm));
82	}
83
84	static int __dwc_pwm_configure_timer(struct dwc_pwm *dwc,
85	struct pwm_device *pwm,
86	const struct pwm_state *state)
87	{
88	u64 tmp;
89	u32 ctrl;
90	u32 high;
91	u32 low;
92
93	/*
94	* Calculate width of low and high period in terms of input clock
95	* periods and check are the result within HW limits between 1 and
96	* 2^32 periods.
97	*/
98	tmp = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, DWC_CLK_PERIOD_NS);
99	if (tmp < 1 \|\| tmp > (1ULL << 32))
100	return -ERANGE;
101	low = tmp - 1;
102
103	tmp = DIV_ROUND_CLOSEST_ULL(state->period - state->duty_cycle,
104	DWC_CLK_PERIOD_NS);
105	if (tmp < 1 \|\| tmp > (1ULL << 32))
106	return -ERANGE;
107	high = tmp - 1;
108
109	/*
110	* Specification says timer usage flow is to disable timer, then
111	* program it followed by enable. It also says Load Count is loaded
112	* into timer after it is enabled - either after a disable or
113	* a reset. Based on measurements it happens also without disable
114	* whenever Load Count is updated. But follow the specification.
115	*/
116	__dwc_pwm_set_enable(dwc, pwm->hwpwm, false);
117
118	/*
119	* Write Load Count and Load Count 2 registers. Former defines the
120	* width of low period and latter the width of high period in terms
121	* multiple of input clock periods:
122	* Width = ((Count + 1) * input clock period).
123	*/
124	dwc_pwm_writel(dwc, low, DWC_TIM_LD_CNT(pwm->hwpwm));
125	dwc_pwm_writel(dwc, high, DWC_TIM_LD_CNT2(pwm->hwpwm));
126
127	/*
128	* Set user-defined mode, timer reloads from Load Count registers
129	* when it counts down to 0.
130	* Set PWM mode, it makes output to toggle and width of low and high
131	* periods are set by Load Count registers.
132	*/
133	ctrl = DWC_TIM_CTRL_MODE_USER \| DWC_TIM_CTRL_PWM;
134	dwc_pwm_writel(dwc, ctrl, DWC_TIM_CTRL(pwm->hwpwm));
135
136	/*
137	* Enable timer. Output starts from low period.
138	*/
139	__dwc_pwm_set_enable(dwc, pwm->hwpwm, state->enabled);
140
141	return 0;
142	}
143
144	static int dwc_pwm_apply(struct pwm_chip chip, struct pwm_device pwm,
145	const struct pwm_state *state)
146	{
147	struct dwc_pwm *dwc = to_dwc_pwm(chip);
148
149	if (state->polarity != PWM_POLARITY_INVERSED)
150	return -EINVAL;
151
152	if (state->enabled) {
153	if (!pwm->state.enabled)
154	pm_runtime_get_sync(chip->dev);
155	return __dwc_pwm_configure_timer(dwc, pwm, state);
156	} else {
157	if (pwm->state.enabled) {
158	__dwc_pwm_set_enable(dwc, pwm->hwpwm, false);
159	pm_runtime_put_sync(chip->dev);
160	}
161	}
162
163	return 0;
164	}
165
166	static void dwc_pwm_get_state(struct pwm_chip chip, struct pwm_device pwm,
167	struct pwm_state *state)
168	{
169	struct dwc_pwm *dwc = to_dwc_pwm(chip);
170	u64 duty, period;
171
172	pm_runtime_get_sync(chip->dev);
173
174	state->enabled = !!(dwc_pwm_readl(dwc,
175	DWC_TIM_CTRL(pwm->hwpwm)) & DWC_TIM_CTRL_EN);
176
177	duty = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(pwm->hwpwm));
178	duty += 1;
179	duty *= DWC_CLK_PERIOD_NS;
180	state->duty_cycle = duty;
181
182	period = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(pwm->hwpwm));
183	period += 1;
184	period *= DWC_CLK_PERIOD_NS;
185	period += duty;
186	state->period = period;
187
188	state->polarity = PWM_POLARITY_INVERSED;
189
190	pm_runtime_put_sync(chip->dev);
191	}
192
193	static const struct pwm_ops dwc_pwm_ops = {
194	.apply = dwc_pwm_apply,
195	.get_state = dwc_pwm_get_state,
196	.owner = THIS_MODULE,
197	};
198
199	static int dwc_pwm_probe(struct pci_dev pci, const struct pci_device_id id)
200	{
201	struct device *dev = &pci->dev;
202	struct dwc_pwm *dwc;
203	int ret;
204
205	dwc = devm_kzalloc(&pci->dev, sizeof(*dwc), GFP_KERNEL);
206	if (!dwc)
207	return -ENOMEM;
208
209	ret = pcim_enable_device(pci);
210	if (ret) {
211	dev_err(&pci->dev,
212	"Failed to enable device (%pe)\n", ERR_PTR(ret));
213	return ret;
214	}
215
216	pci_set_master(pci);
217
218	ret = pcim_iomap_regions(pci, BIT(0), pci_name(pci));
219	if (ret) {
220	dev_err(&pci->dev,
221	"Failed to iomap PCI BAR (%pe)\n", ERR_PTR(ret));
222	return ret;
223	}
224
225	dwc->base = pcim_iomap_table(pci)[0];
226	if (!dwc->base) {
227	dev_err(&pci->dev, "Base address missing\n");
228	return -ENOMEM;
229	}
230
231	pci_set_drvdata(pci, dwc);
232
233	dwc->chip.dev = dev;
234	dwc->chip.ops = &dwc_pwm_ops;
235	dwc->chip.npwm = DWC_TIMERS_TOTAL;
1ed2b3fc JN	236
	237	ret = pwmchip_add(&dwc->chip);
	238	if (ret)
	239	return ret;
	240
	241	pm_runtime_put(dev);
	242	pm_runtime_allow(dev);
	243
	244	return 0;
	245	}
	246
	247	static void dwc_pwm_remove(struct pci_dev *pci)
	248	{
	249	struct dwc_pwm *dwc = pci_get_drvdata(pci);
	250
	251	pm_runtime_forbid(&pci->dev);
	252	pm_runtime_get_noresume(&pci->dev);
	253
	254	pwmchip_remove(&dwc->chip);
	255	}
	256
	257	#ifdef CONFIG_PM_SLEEP
	258	static int dwc_pwm_suspend(struct device *dev)
	259	{
	260	struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
	261	struct dwc_pwm *dwc = pci_get_drvdata(pdev);
	262	int i;
	263
	264	for (i = 0; i < DWC_TIMERS_TOTAL; i++) {
	265	if (dwc->chip.pwms[i].state.enabled) {
	266	dev_err(dev, "PWM %u in use by consumer (%s)\n",
	267	i, dwc->chip.pwms[i].label);
	268	return -EBUSY;
	269	}
	270	dwc->ctx[i].cnt = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(i));
	271	dwc->ctx[i].cnt2 = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(i));
	272	dwc->ctx[i].ctrl = dwc_pwm_readl(dwc, DWC_TIM_CTRL(i));
	273	}
	274
	275	return 0;
	276	}
	277
	278	static int dwc_pwm_resume(struct device *dev)
	279	{
	280	struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
	281	struct dwc_pwm *dwc = pci_get_drvdata(pdev);
	282	int i;
	283
	284	for (i = 0; i < DWC_TIMERS_TOTAL; i++) {
	285	dwc_pwm_writel(dwc, dwc->ctx[i].cnt, DWC_TIM_LD_CNT(i));
	286	dwc_pwm_writel(dwc, dwc->ctx[i].cnt2, DWC_TIM_LD_CNT2(i));
	287	dwc_pwm_writel(dwc, dwc->ctx[i].ctrl, DWC_TIM_CTRL(i));
	288	}
	289
	290	return 0;
	291	}
	292	#endif
	293
	294	static SIMPLE_DEV_PM_OPS(dwc_pwm_pm_ops, dwc_pwm_suspend, dwc_pwm_resume);
	295
	296	static const struct pci_device_id dwc_pwm_id_table[] = {
	297	{ PCI_VDEVICE(INTEL, 0x4bb7) }, /* Elkhart Lake */
	298	{ } /* Terminating Entry */
	299	};
300	MODULE_DEVICE_TABLE(pci, dwc_pwm_id_table);
301
302	static struct pci_driver dwc_pwm_driver = {
303	.name = "pwm-dwc",
304	.probe = dwc_pwm_probe,
305	.remove = dwc_pwm_remove,
306	.id_table = dwc_pwm_id_table,
307	.driver = {
308	.pm = &dwc_pwm_pm_ops,
309	},
310	};
311
312	module_pci_driver(dwc_pwm_driver);
313
314	MODULE_AUTHOR("Felipe Balbi (Intel)");
315	MODULE_AUTHOR("Jarkko Nikula <[email protected]>");
316	MODULE_AUTHOR("Raymond Tan <[email protected]>");
317	MODULE_DESCRIPTION("DesignWare PWM Controller");
318	MODULE_LICENSE("GPL");