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59d5c8b1 AT |
1 | /* |
2 | * Marvell Berlin PWM driver | |
3 | * | |
4 | * Copyright (C) 2015 Marvell Technology Group Ltd. | |
5 | * | |
6 | * Author: Antoine Tenart <antoine.tenart@free-electrons.com> | |
7 | * | |
8 | * This file is licensed under the terms of the GNU General Public | |
9 | * License version 2. This program is licensed "as is" without any | |
10 | * warranty of any kind, whether express or implied. | |
11 | */ | |
12 | ||
13 | #include <linux/clk.h> | |
14 | #include <linux/io.h> | |
15 | #include <linux/kernel.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/pwm.h> | |
bbf0722c | 19 | #include <linux/slab.h> |
59d5c8b1 AT |
20 | |
21 | #define BERLIN_PWM_EN 0x0 | |
22 | #define BERLIN_PWM_ENABLE BIT(0) | |
23 | #define BERLIN_PWM_CONTROL 0x4 | |
24 | #define BERLIN_PWM_PRESCALE_MASK 0x7 | |
25 | #define BERLIN_PWM_PRESCALE_MAX 4096 | |
26 | #define BERLIN_PWM_INVERT_POLARITY BIT(3) | |
27 | #define BERLIN_PWM_DUTY 0x8 | |
28 | #define BERLIN_PWM_TCNT 0xc | |
29 | #define BERLIN_PWM_MAX_TCNT 65535 | |
30 | ||
bbf0722c JZ |
31 | struct berlin_pwm_channel { |
32 | u32 enable; | |
33 | u32 ctrl; | |
34 | u32 duty; | |
35 | u32 tcnt; | |
36 | }; | |
37 | ||
59d5c8b1 AT |
38 | struct berlin_pwm_chip { |
39 | struct pwm_chip chip; | |
40 | struct clk *clk; | |
41 | void __iomem *base; | |
42 | }; | |
43 | ||
44 | static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip) | |
45 | { | |
46 | return container_of(chip, struct berlin_pwm_chip, chip); | |
47 | } | |
48 | ||
49 | static const u32 prescaler_table[] = { | |
50 | 1, 4, 8, 16, 64, 256, 1024, 4096 | |
51 | }; | |
52 | ||
53 | static inline u32 berlin_pwm_readl(struct berlin_pwm_chip *chip, | |
54 | unsigned int channel, unsigned long offset) | |
55 | { | |
56 | return readl_relaxed(chip->base + channel * 0x10 + offset); | |
57 | } | |
58 | ||
59 | static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip, | |
60 | unsigned int channel, u32 value, | |
61 | unsigned long offset) | |
62 | { | |
63 | writel_relaxed(value, chip->base + channel * 0x10 + offset); | |
64 | } | |
65 | ||
bbf0722c JZ |
66 | static int berlin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) |
67 | { | |
68 | struct berlin_pwm_channel *channel; | |
69 | ||
70 | channel = kzalloc(sizeof(*channel), GFP_KERNEL); | |
71 | if (!channel) | |
72 | return -ENOMEM; | |
73 | ||
74 | return pwm_set_chip_data(pwm, channel); | |
75 | } | |
76 | ||
77 | static void berlin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) | |
78 | { | |
79 | struct berlin_pwm_channel *channel = pwm_get_chip_data(pwm); | |
80 | ||
bbf0722c JZ |
81 | kfree(channel); |
82 | } | |
83 | ||
59d5c8b1 AT |
84 | static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev, |
85 | int duty_ns, int period_ns) | |
86 | { | |
87 | struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); | |
88 | unsigned int prescale; | |
89 | u32 value, duty, period; | |
90 | u64 cycles, tmp; | |
91 | ||
92 | cycles = clk_get_rate(pwm->clk); | |
93 | cycles *= period_ns; | |
94 | do_div(cycles, NSEC_PER_SEC); | |
95 | ||
96 | for (prescale = 0; prescale < ARRAY_SIZE(prescaler_table); prescale++) { | |
97 | tmp = cycles; | |
98 | do_div(tmp, prescaler_table[prescale]); | |
99 | ||
100 | if (tmp <= BERLIN_PWM_MAX_TCNT) | |
101 | break; | |
102 | } | |
103 | ||
104 | if (tmp > BERLIN_PWM_MAX_TCNT) | |
105 | return -ERANGE; | |
106 | ||
107 | period = tmp; | |
108 | cycles = tmp * duty_ns; | |
109 | do_div(cycles, period_ns); | |
110 | duty = cycles; | |
111 | ||
112 | value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); | |
113 | value &= ~BERLIN_PWM_PRESCALE_MASK; | |
114 | value |= prescale; | |
115 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL); | |
116 | ||
117 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, duty, BERLIN_PWM_DUTY); | |
118 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, period, BERLIN_PWM_TCNT); | |
119 | ||
120 | return 0; | |
121 | } | |
122 | ||
123 | static int berlin_pwm_set_polarity(struct pwm_chip *chip, | |
124 | struct pwm_device *pwm_dev, | |
125 | enum pwm_polarity polarity) | |
126 | { | |
127 | struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); | |
128 | u32 value; | |
129 | ||
130 | value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL); | |
131 | ||
132 | if (polarity == PWM_POLARITY_NORMAL) | |
133 | value &= ~BERLIN_PWM_INVERT_POLARITY; | |
134 | else | |
135 | value |= BERLIN_PWM_INVERT_POLARITY; | |
136 | ||
137 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL); | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | static int berlin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm_dev) | |
143 | { | |
144 | struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); | |
145 | u32 value; | |
146 | ||
147 | value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); | |
148 | value |= BERLIN_PWM_ENABLE; | |
149 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN); | |
150 | ||
151 | return 0; | |
152 | } | |
153 | ||
154 | static void berlin_pwm_disable(struct pwm_chip *chip, | |
155 | struct pwm_device *pwm_dev) | |
156 | { | |
157 | struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip); | |
158 | u32 value; | |
159 | ||
160 | value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN); | |
161 | value &= ~BERLIN_PWM_ENABLE; | |
162 | berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN); | |
163 | } | |
164 | ||
165 | static const struct pwm_ops berlin_pwm_ops = { | |
bbf0722c JZ |
166 | .request = berlin_pwm_request, |
167 | .free = berlin_pwm_free, | |
59d5c8b1 AT |
168 | .config = berlin_pwm_config, |
169 | .set_polarity = berlin_pwm_set_polarity, | |
170 | .enable = berlin_pwm_enable, | |
171 | .disable = berlin_pwm_disable, | |
172 | .owner = THIS_MODULE, | |
173 | }; | |
174 | ||
175 | static const struct of_device_id berlin_pwm_match[] = { | |
176 | { .compatible = "marvell,berlin-pwm" }, | |
177 | { }, | |
178 | }; | |
179 | MODULE_DEVICE_TABLE(of, berlin_pwm_match); | |
180 | ||
181 | static int berlin_pwm_probe(struct platform_device *pdev) | |
182 | { | |
183 | struct berlin_pwm_chip *pwm; | |
184 | struct resource *res; | |
185 | int ret; | |
186 | ||
187 | pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); | |
188 | if (!pwm) | |
189 | return -ENOMEM; | |
190 | ||
191 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
192 | pwm->base = devm_ioremap_resource(&pdev->dev, res); | |
193 | if (IS_ERR(pwm->base)) | |
194 | return PTR_ERR(pwm->base); | |
195 | ||
196 | pwm->clk = devm_clk_get(&pdev->dev, NULL); | |
197 | if (IS_ERR(pwm->clk)) | |
198 | return PTR_ERR(pwm->clk); | |
199 | ||
200 | ret = clk_prepare_enable(pwm->clk); | |
201 | if (ret) | |
202 | return ret; | |
203 | ||
204 | pwm->chip.dev = &pdev->dev; | |
205 | pwm->chip.ops = &berlin_pwm_ops; | |
206 | pwm->chip.base = -1; | |
207 | pwm->chip.npwm = 4; | |
59d5c8b1 AT |
208 | pwm->chip.of_xlate = of_pwm_xlate_with_flags; |
209 | pwm->chip.of_pwm_n_cells = 3; | |
210 | ||
211 | ret = pwmchip_add(&pwm->chip); | |
212 | if (ret < 0) { | |
213 | dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); | |
214 | clk_disable_unprepare(pwm->clk); | |
215 | return ret; | |
216 | } | |
217 | ||
218 | platform_set_drvdata(pdev, pwm); | |
219 | ||
220 | return 0; | |
221 | } | |
222 | ||
223 | static int berlin_pwm_remove(struct platform_device *pdev) | |
224 | { | |
225 | struct berlin_pwm_chip *pwm = platform_get_drvdata(pdev); | |
226 | int ret; | |
227 | ||
228 | ret = pwmchip_remove(&pwm->chip); | |
229 | clk_disable_unprepare(pwm->clk); | |
230 | ||
231 | return ret; | |
232 | } | |
233 | ||
bbf0722c JZ |
234 | #ifdef CONFIG_PM_SLEEP |
235 | static int berlin_pwm_suspend(struct device *dev) | |
236 | { | |
237 | struct berlin_pwm_chip *pwm = dev_get_drvdata(dev); | |
238 | unsigned int i; | |
239 | ||
240 | for (i = 0; i < pwm->chip.npwm; i++) { | |
241 | struct berlin_pwm_channel *channel; | |
242 | ||
243 | channel = pwm_get_chip_data(&pwm->chip.pwms[i]); | |
244 | if (!channel) | |
245 | continue; | |
246 | ||
247 | channel->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE); | |
248 | channel->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL); | |
249 | channel->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY); | |
250 | channel->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT); | |
251 | } | |
252 | ||
253 | clk_disable_unprepare(pwm->clk); | |
254 | ||
255 | return 0; | |
256 | } | |
257 | ||
258 | static int berlin_pwm_resume(struct device *dev) | |
259 | { | |
260 | struct berlin_pwm_chip *pwm = dev_get_drvdata(dev); | |
261 | unsigned int i; | |
262 | int ret; | |
263 | ||
264 | ret = clk_prepare_enable(pwm->clk); | |
265 | if (ret) | |
266 | return ret; | |
267 | ||
268 | for (i = 0; i < pwm->chip.npwm; i++) { | |
269 | struct berlin_pwm_channel *channel; | |
270 | ||
271 | channel = pwm_get_chip_data(&pwm->chip.pwms[i]); | |
272 | if (!channel) | |
273 | continue; | |
274 | ||
275 | berlin_pwm_writel(pwm, i, channel->ctrl, BERLIN_PWM_CONTROL); | |
276 | berlin_pwm_writel(pwm, i, channel->duty, BERLIN_PWM_DUTY); | |
277 | berlin_pwm_writel(pwm, i, channel->tcnt, BERLIN_PWM_TCNT); | |
278 | berlin_pwm_writel(pwm, i, channel->enable, BERLIN_PWM_ENABLE); | |
279 | } | |
280 | ||
281 | return 0; | |
282 | } | |
283 | #endif | |
284 | ||
285 | static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend, | |
286 | berlin_pwm_resume); | |
287 | ||
59d5c8b1 AT |
288 | static struct platform_driver berlin_pwm_driver = { |
289 | .probe = berlin_pwm_probe, | |
290 | .remove = berlin_pwm_remove, | |
291 | .driver = { | |
292 | .name = "berlin-pwm", | |
293 | .of_match_table = berlin_pwm_match, | |
bbf0722c | 294 | .pm = &berlin_pwm_pm_ops, |
59d5c8b1 AT |
295 | }, |
296 | }; | |
297 | module_platform_driver(berlin_pwm_driver); | |
298 | ||
299 | MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>"); | |
300 | MODULE_DESCRIPTION("Marvell Berlin PWM driver"); | |
301 | MODULE_LICENSE("GPL v2"); |