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ef12379f HS |
1 | /* |
2 | * Simple PWM driver for EP93XX | |
3 | * | |
4 | * (c) Copyright 2009 Matthieu Crapet <mcrapet@gmail.com> | |
5 | * (c) Copyright 2009 H Hartley Sweeten <hsweeten@visionengravers.com> | |
6 | * | |
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 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
12 | * EP9307 has only one channel: | |
13 | * - PWMOUT | |
14 | * | |
15 | * EP9301/02/12/15 have two channels: | |
16 | * - PWMOUT | |
17 | * - PWMOUT1 (alternate function for EGPIO14) | |
18 | */ | |
19 | ||
20 | #include <linux/module.h> | |
21 | #include <linux/platform_device.h> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
ef12379f HS |
23 | #include <linux/clk.h> |
24 | #include <linux/err.h> | |
25 | #include <linux/io.h> | |
26 | ||
27 | #include <mach/platform.h> | |
28 | ||
29 | #define EP93XX_PWMx_TERM_COUNT 0x00 | |
30 | #define EP93XX_PWMx_DUTY_CYCLE 0x04 | |
31 | #define EP93XX_PWMx_ENABLE 0x08 | |
32 | #define EP93XX_PWMx_INVERT 0x0C | |
33 | ||
34 | #define EP93XX_PWM_MAX_COUNT 0xFFFF | |
35 | ||
36 | struct ep93xx_pwm { | |
37 | void __iomem *mmio_base; | |
38 | struct clk *clk; | |
39 | u32 duty_percent; | |
40 | }; | |
41 | ||
42 | static inline void ep93xx_pwm_writel(struct ep93xx_pwm *pwm, | |
43 | unsigned int val, unsigned int off) | |
44 | { | |
45 | __raw_writel(val, pwm->mmio_base + off); | |
46 | } | |
47 | ||
48 | static inline unsigned int ep93xx_pwm_readl(struct ep93xx_pwm *pwm, | |
49 | unsigned int off) | |
50 | { | |
51 | return __raw_readl(pwm->mmio_base + off); | |
52 | } | |
53 | ||
54 | static inline void ep93xx_pwm_write_tc(struct ep93xx_pwm *pwm, u16 value) | |
55 | { | |
56 | ep93xx_pwm_writel(pwm, value, EP93XX_PWMx_TERM_COUNT); | |
57 | } | |
58 | ||
59 | static inline u16 ep93xx_pwm_read_tc(struct ep93xx_pwm *pwm) | |
60 | { | |
61 | return ep93xx_pwm_readl(pwm, EP93XX_PWMx_TERM_COUNT); | |
62 | } | |
63 | ||
64 | static inline void ep93xx_pwm_write_dc(struct ep93xx_pwm *pwm, u16 value) | |
65 | { | |
66 | ep93xx_pwm_writel(pwm, value, EP93XX_PWMx_DUTY_CYCLE); | |
67 | } | |
68 | ||
69 | static inline void ep93xx_pwm_enable(struct ep93xx_pwm *pwm) | |
70 | { | |
71 | ep93xx_pwm_writel(pwm, 0x1, EP93XX_PWMx_ENABLE); | |
72 | } | |
73 | ||
74 | static inline void ep93xx_pwm_disable(struct ep93xx_pwm *pwm) | |
75 | { | |
76 | ep93xx_pwm_writel(pwm, 0x0, EP93XX_PWMx_ENABLE); | |
77 | } | |
78 | ||
79 | static inline int ep93xx_pwm_is_enabled(struct ep93xx_pwm *pwm) | |
80 | { | |
81 | return ep93xx_pwm_readl(pwm, EP93XX_PWMx_ENABLE) & 0x1; | |
82 | } | |
83 | ||
84 | static inline void ep93xx_pwm_invert(struct ep93xx_pwm *pwm) | |
85 | { | |
86 | ep93xx_pwm_writel(pwm, 0x1, EP93XX_PWMx_INVERT); | |
87 | } | |
88 | ||
89 | static inline void ep93xx_pwm_normal(struct ep93xx_pwm *pwm) | |
90 | { | |
91 | ep93xx_pwm_writel(pwm, 0x0, EP93XX_PWMx_INVERT); | |
92 | } | |
93 | ||
94 | static inline int ep93xx_pwm_is_inverted(struct ep93xx_pwm *pwm) | |
95 | { | |
96 | return ep93xx_pwm_readl(pwm, EP93XX_PWMx_INVERT) & 0x1; | |
97 | } | |
98 | ||
99 | /* | |
100 | * /sys/devices/platform/ep93xx-pwm.N | |
101 | * /min_freq read-only minimum pwm output frequency | |
102 | * /max_req read-only maximum pwm output frequency | |
103 | * /freq read-write pwm output frequency (0 = disable output) | |
104 | * /duty_percent read-write pwm duty cycle percent (1..99) | |
105 | * /invert read-write invert pwm output | |
106 | */ | |
107 | ||
108 | static ssize_t ep93xx_pwm_get_min_freq(struct device *dev, | |
109 | struct device_attribute *attr, char *buf) | |
110 | { | |
111 | struct platform_device *pdev = to_platform_device(dev); | |
112 | struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); | |
113 | unsigned long rate = clk_get_rate(pwm->clk); | |
114 | ||
115 | return sprintf(buf, "%ld\n", rate / (EP93XX_PWM_MAX_COUNT + 1)); | |
116 | } | |
117 | ||
118 | static ssize_t ep93xx_pwm_get_max_freq(struct device *dev, | |
119 | struct device_attribute *attr, char *buf) | |
120 | { | |
121 | struct platform_device *pdev = to_platform_device(dev); | |
122 | struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); | |
123 | unsigned long rate = clk_get_rate(pwm->clk); | |
124 | ||
125 | return sprintf(buf, "%ld\n", rate / 2); | |
126 | } | |
127 | ||
128 | static ssize_t ep93xx_pwm_get_freq(struct device *dev, | |
129 | struct device_attribute *attr, char *buf) | |
130 | { | |
131 | struct platform_device *pdev = to_platform_device(dev); | |
132 | struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); | |
133 | ||
134 | if (ep93xx_pwm_is_enabled(pwm)) { | |
135 | unsigned long rate = clk_get_rate(pwm->clk); | |
136 | u16 term = ep93xx_pwm_read_tc(pwm); | |
137 | ||
138 | return sprintf(buf, "%ld\n", rate / (term + 1)); | |
139 | } else { | |
140 | return sprintf(buf, "disabled\n"); | |
141 | } | |
142 | } | |
143 | ||
144 | static ssize_t ep93xx_pwm_set_freq(struct device *dev, | |
145 | struct device_attribute *attr, const char *buf, size_t count) | |
146 | { | |
147 | struct platform_device *pdev = to_platform_device(dev); | |
148 | struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); | |
149 | long val; | |
150 | int err; | |
151 | ||
152 | err = strict_strtol(buf, 10, &val); | |
153 | if (err) | |
154 | return -EINVAL; | |
155 | ||
156 | if (val == 0) { | |
157 | ep93xx_pwm_disable(pwm); | |
158 | } else if (val <= (clk_get_rate(pwm->clk) / 2)) { | |
159 | u32 term, duty; | |
160 | ||
161 | val = (clk_get_rate(pwm->clk) / val) - 1; | |
162 | if (val > EP93XX_PWM_MAX_COUNT) | |
163 | val = EP93XX_PWM_MAX_COUNT; | |
164 | if (val < 1) | |
165 | val = 1; | |
166 | ||
167 | term = ep93xx_pwm_read_tc(pwm); | |
168 | duty = ((val + 1) * pwm->duty_percent / 100) - 1; | |
169 | ||
170 | /* If pwm is running, order is important */ | |
171 | if (val > term) { | |
172 | ep93xx_pwm_write_tc(pwm, val); | |
173 | ep93xx_pwm_write_dc(pwm, duty); | |
174 | } else { | |
175 | ep93xx_pwm_write_dc(pwm, duty); | |
176 | ep93xx_pwm_write_tc(pwm, val); | |
177 | } | |
178 | ||
179 | if (!ep93xx_pwm_is_enabled(pwm)) | |
180 | ep93xx_pwm_enable(pwm); | |
181 | } else { | |
182 | return -EINVAL; | |
183 | } | |
184 | ||
185 | return count; | |
186 | } | |
187 | ||
188 | static ssize_t ep93xx_pwm_get_duty_percent(struct device *dev, | |
189 | struct device_attribute *attr, char *buf) | |
190 | { | |
191 | struct platform_device *pdev = to_platform_device(dev); | |
192 | struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); | |
193 | ||
194 | return sprintf(buf, "%d\n", pwm->duty_percent); | |
195 | } | |
196 | ||
197 | static ssize_t ep93xx_pwm_set_duty_percent(struct device *dev, | |
198 | struct device_attribute *attr, const char *buf, size_t count) | |
199 | { | |
200 | struct platform_device *pdev = to_platform_device(dev); | |
201 | struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); | |
202 | long val; | |
203 | int err; | |
204 | ||
205 | err = strict_strtol(buf, 10, &val); | |
206 | if (err) | |
207 | return -EINVAL; | |
208 | ||
209 | if (val > 0 && val < 100) { | |
210 | u32 term = ep93xx_pwm_read_tc(pwm); | |
211 | ep93xx_pwm_write_dc(pwm, ((term + 1) * val / 100) - 1); | |
212 | pwm->duty_percent = val; | |
213 | return count; | |
214 | } | |
215 | ||
216 | return -EINVAL; | |
217 | } | |
218 | ||
219 | static ssize_t ep93xx_pwm_get_invert(struct device *dev, | |
220 | struct device_attribute *attr, char *buf) | |
221 | { | |
222 | struct platform_device *pdev = to_platform_device(dev); | |
223 | struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); | |
224 | ||
225 | return sprintf(buf, "%d\n", ep93xx_pwm_is_inverted(pwm)); | |
226 | } | |
227 | ||
228 | static ssize_t ep93xx_pwm_set_invert(struct device *dev, | |
229 | struct device_attribute *attr, const char *buf, size_t count) | |
230 | { | |
231 | struct platform_device *pdev = to_platform_device(dev); | |
232 | struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); | |
233 | long val; | |
234 | int err; | |
235 | ||
236 | err = strict_strtol(buf, 10, &val); | |
237 | if (err) | |
238 | return -EINVAL; | |
239 | ||
240 | if (val == 0) | |
241 | ep93xx_pwm_normal(pwm); | |
242 | else if (val == 1) | |
243 | ep93xx_pwm_invert(pwm); | |
244 | else | |
245 | return -EINVAL; | |
246 | ||
247 | return count; | |
248 | } | |
249 | ||
250 | static DEVICE_ATTR(min_freq, S_IRUGO, ep93xx_pwm_get_min_freq, NULL); | |
251 | static DEVICE_ATTR(max_freq, S_IRUGO, ep93xx_pwm_get_max_freq, NULL); | |
deb187e7 | 252 | static DEVICE_ATTR(freq, S_IWUSR | S_IRUGO, |
ef12379f | 253 | ep93xx_pwm_get_freq, ep93xx_pwm_set_freq); |
deb187e7 | 254 | static DEVICE_ATTR(duty_percent, S_IWUSR | S_IRUGO, |
ef12379f | 255 | ep93xx_pwm_get_duty_percent, ep93xx_pwm_set_duty_percent); |
deb187e7 | 256 | static DEVICE_ATTR(invert, S_IWUSR | S_IRUGO, |
ef12379f HS |
257 | ep93xx_pwm_get_invert, ep93xx_pwm_set_invert); |
258 | ||
259 | static struct attribute *ep93xx_pwm_attrs[] = { | |
260 | &dev_attr_min_freq.attr, | |
261 | &dev_attr_max_freq.attr, | |
262 | &dev_attr_freq.attr, | |
263 | &dev_attr_duty_percent.attr, | |
264 | &dev_attr_invert.attr, | |
265 | NULL | |
266 | }; | |
267 | ||
268 | static const struct attribute_group ep93xx_pwm_sysfs_files = { | |
269 | .attrs = ep93xx_pwm_attrs, | |
270 | }; | |
271 | ||
272 | static int __init ep93xx_pwm_probe(struct platform_device *pdev) | |
273 | { | |
274 | struct ep93xx_pwm *pwm; | |
275 | struct resource *res; | |
276 | int err; | |
277 | ||
278 | err = ep93xx_pwm_acquire_gpio(pdev); | |
279 | if (err) | |
280 | return err; | |
281 | ||
282 | pwm = kzalloc(sizeof(struct ep93xx_pwm), GFP_KERNEL); | |
283 | if (!pwm) { | |
284 | err = -ENOMEM; | |
285 | goto fail_no_mem; | |
286 | } | |
287 | ||
288 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
289 | if (res == NULL) { | |
290 | err = -ENXIO; | |
291 | goto fail_no_mem_resource; | |
292 | } | |
293 | ||
294 | res = request_mem_region(res->start, resource_size(res), pdev->name); | |
295 | if (res == NULL) { | |
296 | err = -EBUSY; | |
297 | goto fail_no_mem_resource; | |
298 | } | |
299 | ||
300 | pwm->mmio_base = ioremap(res->start, resource_size(res)); | |
301 | if (pwm->mmio_base == NULL) { | |
302 | err = -ENXIO; | |
303 | goto fail_no_ioremap; | |
304 | } | |
305 | ||
306 | err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files); | |
307 | if (err) | |
308 | goto fail_no_sysfs; | |
309 | ||
310 | pwm->clk = clk_get(&pdev->dev, "pwm_clk"); | |
311 | if (IS_ERR(pwm->clk)) { | |
312 | err = PTR_ERR(pwm->clk); | |
313 | goto fail_no_clk; | |
314 | } | |
315 | ||
316 | pwm->duty_percent = 50; | |
317 | ||
318 | platform_set_drvdata(pdev, pwm); | |
319 | ||
320 | /* disable pwm at startup. Avoids zero value. */ | |
321 | ep93xx_pwm_disable(pwm); | |
322 | ep93xx_pwm_write_tc(pwm, EP93XX_PWM_MAX_COUNT); | |
323 | ep93xx_pwm_write_dc(pwm, EP93XX_PWM_MAX_COUNT / 2); | |
324 | ||
325 | clk_enable(pwm->clk); | |
326 | ||
327 | return 0; | |
328 | ||
329 | fail_no_clk: | |
330 | sysfs_remove_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files); | |
331 | fail_no_sysfs: | |
332 | iounmap(pwm->mmio_base); | |
333 | fail_no_ioremap: | |
334 | release_mem_region(res->start, resource_size(res)); | |
335 | fail_no_mem_resource: | |
336 | kfree(pwm); | |
337 | fail_no_mem: | |
338 | ep93xx_pwm_release_gpio(pdev); | |
339 | return err; | |
340 | } | |
341 | ||
342 | static int __exit ep93xx_pwm_remove(struct platform_device *pdev) | |
343 | { | |
344 | struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); | |
345 | struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
346 | ||
347 | ep93xx_pwm_disable(pwm); | |
348 | clk_disable(pwm->clk); | |
349 | clk_put(pwm->clk); | |
350 | platform_set_drvdata(pdev, NULL); | |
351 | sysfs_remove_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files); | |
352 | iounmap(pwm->mmio_base); | |
353 | release_mem_region(res->start, resource_size(res)); | |
354 | kfree(pwm); | |
355 | ep93xx_pwm_release_gpio(pdev); | |
356 | ||
357 | return 0; | |
358 | } | |
359 | ||
360 | static struct platform_driver ep93xx_pwm_driver = { | |
361 | .driver = { | |
362 | .name = "ep93xx-pwm", | |
363 | .owner = THIS_MODULE, | |
364 | }, | |
365 | .remove = __exit_p(ep93xx_pwm_remove), | |
366 | }; | |
367 | ||
ead050de | 368 | module_platform_driver_probe(ep93xx_pwm_driver, ep93xx_pwm_probe); |
ef12379f HS |
369 | |
370 | MODULE_AUTHOR("Matthieu Crapet <mcrapet@gmail.com>, " | |
371 | "H Hartley Sweeten <hsweeten@visionengravers.com>"); | |
372 | MODULE_DESCRIPTION("EP93xx PWM driver"); | |
373 | MODULE_LICENSE("GPL"); | |
374 | MODULE_ALIAS("platform:ep93xx-pwm"); |