xref: /openbmc/linux/drivers/pwm/pwm-hibvt.c (revision 2fa5ebe3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PWM Controller Driver for HiSilicon BVT SoCs
4  *
5  * Copyright (c) 2016 HiSilicon Technologies Co., Ltd.
6  */
7 
8 #include <linux/bitops.h>
9 #include <linux/clk.h>
10 #include <linux/delay.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/of_device.h>
14 #include <linux/platform_device.h>
15 #include <linux/pwm.h>
16 #include <linux/reset.h>
17 
18 #define PWM_CFG0_ADDR(x)    (((x) * 0x20) + 0x0)
19 #define PWM_CFG1_ADDR(x)    (((x) * 0x20) + 0x4)
20 #define PWM_CFG2_ADDR(x)    (((x) * 0x20) + 0x8)
21 #define PWM_CTRL_ADDR(x)    (((x) * 0x20) + 0xC)
22 
23 #define PWM_ENABLE_SHIFT    0
24 #define PWM_ENABLE_MASK     BIT(0)
25 
26 #define PWM_POLARITY_SHIFT  1
27 #define PWM_POLARITY_MASK   BIT(1)
28 
29 #define PWM_KEEP_SHIFT      2
30 #define PWM_KEEP_MASK       BIT(2)
31 
32 #define PWM_PERIOD_MASK     GENMASK(31, 0)
33 #define PWM_DUTY_MASK       GENMASK(31, 0)
34 
35 struct hibvt_pwm_chip {
36 	struct pwm_chip	chip;
37 	struct clk *clk;
38 	void __iomem *base;
39 	struct reset_control *rstc;
40 	const struct hibvt_pwm_soc *soc;
41 };
42 
43 struct hibvt_pwm_soc {
44 	u32 num_pwms;
45 	bool quirk_force_enable;
46 };
47 
48 static const struct hibvt_pwm_soc hi3516cv300_soc_info = {
49 	.num_pwms = 4,
50 };
51 
52 static const struct hibvt_pwm_soc hi3519v100_soc_info = {
53 	.num_pwms = 8,
54 };
55 
56 static const struct hibvt_pwm_soc hi3559v100_shub_soc_info = {
57 	.num_pwms = 8,
58 	.quirk_force_enable = true,
59 };
60 
61 static const struct hibvt_pwm_soc hi3559v100_soc_info = {
62 	.num_pwms = 2,
63 	.quirk_force_enable = true,
64 };
65 
66 static inline struct hibvt_pwm_chip *to_hibvt_pwm_chip(struct pwm_chip *chip)
67 {
68 	return container_of(chip, struct hibvt_pwm_chip, chip);
69 }
70 
71 static void hibvt_pwm_set_bits(void __iomem *base, u32 offset,
72 					u32 mask, u32 data)
73 {
74 	void __iomem *address = base + offset;
75 	u32 value;
76 
77 	value = readl(address);
78 	value &= ~mask;
79 	value |= (data & mask);
80 	writel(value, address);
81 }
82 
83 static void hibvt_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
84 {
85 	struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
86 
87 	hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
88 			PWM_ENABLE_MASK, 0x1);
89 }
90 
91 static void hibvt_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
92 {
93 	struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
94 
95 	hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
96 			PWM_ENABLE_MASK, 0x0);
97 }
98 
99 static void hibvt_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
100 					int duty_cycle_ns, int period_ns)
101 {
102 	struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
103 	u32 freq, period, duty;
104 
105 	freq = div_u64(clk_get_rate(hi_pwm_chip->clk), 1000000);
106 
107 	period = div_u64(freq * period_ns, 1000);
108 	duty = div_u64(period * duty_cycle_ns, period_ns);
109 
110 	hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CFG0_ADDR(pwm->hwpwm),
111 			PWM_PERIOD_MASK, period);
112 
113 	hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CFG1_ADDR(pwm->hwpwm),
114 			PWM_DUTY_MASK, duty);
115 }
116 
117 static void hibvt_pwm_set_polarity(struct pwm_chip *chip,
118 					struct pwm_device *pwm,
119 					enum pwm_polarity polarity)
120 {
121 	struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
122 
123 	if (polarity == PWM_POLARITY_INVERSED)
124 		hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
125 				PWM_POLARITY_MASK, (0x1 << PWM_POLARITY_SHIFT));
126 	else
127 		hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
128 				PWM_POLARITY_MASK, (0x0 << PWM_POLARITY_SHIFT));
129 }
130 
131 static int hibvt_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
132 			       struct pwm_state *state)
133 {
134 	struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
135 	void __iomem *base;
136 	u32 freq, value;
137 
138 	freq = div_u64(clk_get_rate(hi_pwm_chip->clk), 1000000);
139 	base = hi_pwm_chip->base;
140 
141 	value = readl(base + PWM_CFG0_ADDR(pwm->hwpwm));
142 	state->period = div_u64(value * 1000, freq);
143 
144 	value = readl(base + PWM_CFG1_ADDR(pwm->hwpwm));
145 	state->duty_cycle = div_u64(value * 1000, freq);
146 
147 	value = readl(base + PWM_CTRL_ADDR(pwm->hwpwm));
148 	state->enabled = (PWM_ENABLE_MASK & value);
149 	state->polarity = (PWM_POLARITY_MASK & value) ? PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;
150 
151 	return 0;
152 }
153 
154 static int hibvt_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
155 			   const struct pwm_state *state)
156 {
157 	struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
158 
159 	if (state->polarity != pwm->state.polarity)
160 		hibvt_pwm_set_polarity(chip, pwm, state->polarity);
161 
162 	if (state->period != pwm->state.period ||
163 	    state->duty_cycle != pwm->state.duty_cycle) {
164 		hibvt_pwm_config(chip, pwm, state->duty_cycle, state->period);
165 
166 		/*
167 		 * Some implementations require the PWM to be enabled twice
168 		 * each time the duty cycle is refreshed.
169 		 */
170 		if (hi_pwm_chip->soc->quirk_force_enable && state->enabled)
171 			hibvt_pwm_enable(chip, pwm);
172 	}
173 
174 	if (state->enabled != pwm->state.enabled) {
175 		if (state->enabled)
176 			hibvt_pwm_enable(chip, pwm);
177 		else
178 			hibvt_pwm_disable(chip, pwm);
179 	}
180 
181 	return 0;
182 }
183 
184 static const struct pwm_ops hibvt_pwm_ops = {
185 	.get_state = hibvt_pwm_get_state,
186 	.apply = hibvt_pwm_apply,
187 
188 	.owner = THIS_MODULE,
189 };
190 
191 static int hibvt_pwm_probe(struct platform_device *pdev)
192 {
193 	const struct hibvt_pwm_soc *soc =
194 				of_device_get_match_data(&pdev->dev);
195 	struct hibvt_pwm_chip *pwm_chip;
196 	int ret, i;
197 
198 	pwm_chip = devm_kzalloc(&pdev->dev, sizeof(*pwm_chip), GFP_KERNEL);
199 	if (pwm_chip == NULL)
200 		return -ENOMEM;
201 
202 	pwm_chip->clk = devm_clk_get(&pdev->dev, NULL);
203 	if (IS_ERR(pwm_chip->clk)) {
204 		dev_err(&pdev->dev, "getting clock failed with %ld\n",
205 				PTR_ERR(pwm_chip->clk));
206 		return PTR_ERR(pwm_chip->clk);
207 	}
208 
209 	pwm_chip->chip.ops = &hibvt_pwm_ops;
210 	pwm_chip->chip.dev = &pdev->dev;
211 	pwm_chip->chip.npwm = soc->num_pwms;
212 	pwm_chip->soc = soc;
213 
214 	pwm_chip->base = devm_platform_ioremap_resource(pdev, 0);
215 	if (IS_ERR(pwm_chip->base))
216 		return PTR_ERR(pwm_chip->base);
217 
218 	ret = clk_prepare_enable(pwm_chip->clk);
219 	if (ret < 0)
220 		return ret;
221 
222 	pwm_chip->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
223 	if (IS_ERR(pwm_chip->rstc)) {
224 		clk_disable_unprepare(pwm_chip->clk);
225 		return PTR_ERR(pwm_chip->rstc);
226 	}
227 
228 	reset_control_assert(pwm_chip->rstc);
229 	msleep(30);
230 	reset_control_deassert(pwm_chip->rstc);
231 
232 	ret = pwmchip_add(&pwm_chip->chip);
233 	if (ret < 0) {
234 		clk_disable_unprepare(pwm_chip->clk);
235 		return ret;
236 	}
237 
238 	for (i = 0; i < pwm_chip->chip.npwm; i++) {
239 		hibvt_pwm_set_bits(pwm_chip->base, PWM_CTRL_ADDR(i),
240 				PWM_KEEP_MASK, (0x1 << PWM_KEEP_SHIFT));
241 	}
242 
243 	platform_set_drvdata(pdev, pwm_chip);
244 
245 	return 0;
246 }
247 
248 static int hibvt_pwm_remove(struct platform_device *pdev)
249 {
250 	struct hibvt_pwm_chip *pwm_chip;
251 
252 	pwm_chip = platform_get_drvdata(pdev);
253 
254 	pwmchip_remove(&pwm_chip->chip);
255 
256 	reset_control_assert(pwm_chip->rstc);
257 	msleep(30);
258 	reset_control_deassert(pwm_chip->rstc);
259 
260 	clk_disable_unprepare(pwm_chip->clk);
261 
262 	return 0;
263 }
264 
265 static const struct of_device_id hibvt_pwm_of_match[] = {
266 	{ .compatible = "hisilicon,hi3516cv300-pwm",
267 	  .data = &hi3516cv300_soc_info },
268 	{ .compatible = "hisilicon,hi3519v100-pwm",
269 	  .data = &hi3519v100_soc_info },
270 	{ .compatible = "hisilicon,hi3559v100-shub-pwm",
271 	  .data = &hi3559v100_shub_soc_info },
272 	{ .compatible = "hisilicon,hi3559v100-pwm",
273 	  .data = &hi3559v100_soc_info },
274 	{  }
275 };
276 MODULE_DEVICE_TABLE(of, hibvt_pwm_of_match);
277 
278 static struct platform_driver hibvt_pwm_driver = {
279 	.driver = {
280 		.name = "hibvt-pwm",
281 		.of_match_table = hibvt_pwm_of_match,
282 	},
283 	.probe = hibvt_pwm_probe,
284 	.remove	= hibvt_pwm_remove,
285 };
286 module_platform_driver(hibvt_pwm_driver);
287 
288 MODULE_AUTHOR("Jian Yuan");
289 MODULE_DESCRIPTION("HiSilicon BVT SoCs PWM driver");
290 MODULE_LICENSE("GPL");
291