Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 | /*
* Simple PWM driver for EP93XX
*
* (c) Copyright 2009 Matthieu Crapet <mcrapet@gmail.com>
* (c) Copyright 2009 H Hartley Sweeten <hsweeten@visionengravers.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* EP9307 has only one channel:
* - PWMOUT
*
* EP9301/02/12/15 have two channels:
* - PWMOUT
* - PWMOUT1 (alternate function for EGPIO14)
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <mach/platform.h>
#define EP93XX_PWMx_TERM_COUNT 0x00
#define EP93XX_PWMx_DUTY_CYCLE 0x04
#define EP93XX_PWMx_ENABLE 0x08
#define EP93XX_PWMx_INVERT 0x0C
#define EP93XX_PWM_MAX_COUNT 0xFFFF
struct ep93xx_pwm {
void __iomem *mmio_base;
struct clk *clk;
u32 duty_percent;
};
static inline void ep93xx_pwm_writel(struct ep93xx_pwm *pwm,
unsigned int val, unsigned int off)
{
__raw_writel(val, pwm->mmio_base + off);
}
static inline unsigned int ep93xx_pwm_readl(struct ep93xx_pwm *pwm,
unsigned int off)
{
return __raw_readl(pwm->mmio_base + off);
}
static inline void ep93xx_pwm_write_tc(struct ep93xx_pwm *pwm, u16 value)
{
ep93xx_pwm_writel(pwm, value, EP93XX_PWMx_TERM_COUNT);
}
static inline u16 ep93xx_pwm_read_tc(struct ep93xx_pwm *pwm)
{
return ep93xx_pwm_readl(pwm, EP93XX_PWMx_TERM_COUNT);
}
static inline void ep93xx_pwm_write_dc(struct ep93xx_pwm *pwm, u16 value)
{
ep93xx_pwm_writel(pwm, value, EP93XX_PWMx_DUTY_CYCLE);
}
static inline void ep93xx_pwm_enable(struct ep93xx_pwm *pwm)
{
ep93xx_pwm_writel(pwm, 0x1, EP93XX_PWMx_ENABLE);
}
static inline void ep93xx_pwm_disable(struct ep93xx_pwm *pwm)
{
ep93xx_pwm_writel(pwm, 0x0, EP93XX_PWMx_ENABLE);
}
static inline int ep93xx_pwm_is_enabled(struct ep93xx_pwm *pwm)
{
return ep93xx_pwm_readl(pwm, EP93XX_PWMx_ENABLE) & 0x1;
}
static inline void ep93xx_pwm_invert(struct ep93xx_pwm *pwm)
{
ep93xx_pwm_writel(pwm, 0x1, EP93XX_PWMx_INVERT);
}
static inline void ep93xx_pwm_normal(struct ep93xx_pwm *pwm)
{
ep93xx_pwm_writel(pwm, 0x0, EP93XX_PWMx_INVERT);
}
static inline int ep93xx_pwm_is_inverted(struct ep93xx_pwm *pwm)
{
return ep93xx_pwm_readl(pwm, EP93XX_PWMx_INVERT) & 0x1;
}
/*
* /sys/devices/platform/ep93xx-pwm.N
* /min_freq read-only minimum pwm output frequency
* /max_req read-only maximum pwm output frequency
* /freq read-write pwm output frequency (0 = disable output)
* /duty_percent read-write pwm duty cycle percent (1..99)
* /invert read-write invert pwm output
*/
static ssize_t ep93xx_pwm_get_min_freq(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct platform_device *pdev = to_platform_device(dev);
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
unsigned long rate = clk_get_rate(pwm->clk);
return sprintf(buf, "%ld\n", rate / (EP93XX_PWM_MAX_COUNT + 1));
}
static ssize_t ep93xx_pwm_get_max_freq(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct platform_device *pdev = to_platform_device(dev);
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
unsigned long rate = clk_get_rate(pwm->clk);
return sprintf(buf, "%ld\n", rate / 2);
}
static ssize_t ep93xx_pwm_get_freq(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct platform_device *pdev = to_platform_device(dev);
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
if (ep93xx_pwm_is_enabled(pwm)) {
unsigned long rate = clk_get_rate(pwm->clk);
u16 term = ep93xx_pwm_read_tc(pwm);
return sprintf(buf, "%ld\n", rate / (term + 1));
} else {
return sprintf(buf, "disabled\n");
}
}
static ssize_t ep93xx_pwm_set_freq(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct platform_device *pdev = to_platform_device(dev);
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
long val;
int err;
err = strict_strtol(buf, 10, &val);
if (err)
return -EINVAL;
if (val == 0) {
ep93xx_pwm_disable(pwm);
} else if (val <= (clk_get_rate(pwm->clk) / 2)) {
u32 term, duty;
val = (clk_get_rate(pwm->clk) / val) - 1;
if (val > EP93XX_PWM_MAX_COUNT)
val = EP93XX_PWM_MAX_COUNT;
if (val < 1)
val = 1;
term = ep93xx_pwm_read_tc(pwm);
duty = ((val + 1) * pwm->duty_percent / 100) - 1;
/* If pwm is running, order is important */
if (val > term) {
ep93xx_pwm_write_tc(pwm, val);
ep93xx_pwm_write_dc(pwm, duty);
} else {
ep93xx_pwm_write_dc(pwm, duty);
ep93xx_pwm_write_tc(pwm, val);
}
if (!ep93xx_pwm_is_enabled(pwm))
ep93xx_pwm_enable(pwm);
} else {
return -EINVAL;
}
return count;
}
static ssize_t ep93xx_pwm_get_duty_percent(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct platform_device *pdev = to_platform_device(dev);
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
return sprintf(buf, "%d\n", pwm->duty_percent);
}
static ssize_t ep93xx_pwm_set_duty_percent(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct platform_device *pdev = to_platform_device(dev);
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
long val;
int err;
err = strict_strtol(buf, 10, &val);
if (err)
return -EINVAL;
if (val > 0 && val < 100) {
u32 term = ep93xx_pwm_read_tc(pwm);
ep93xx_pwm_write_dc(pwm, ((term + 1) * val / 100) - 1);
pwm->duty_percent = val;
return count;
}
return -EINVAL;
}
static ssize_t ep93xx_pwm_get_invert(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct platform_device *pdev = to_platform_device(dev);
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
return sprintf(buf, "%d\n", ep93xx_pwm_is_inverted(pwm));
}
static ssize_t ep93xx_pwm_set_invert(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct platform_device *pdev = to_platform_device(dev);
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
long val;
int err;
err = strict_strtol(buf, 10, &val);
if (err)
return -EINVAL;
if (val == 0)
ep93xx_pwm_normal(pwm);
else if (val == 1)
ep93xx_pwm_invert(pwm);
else
return -EINVAL;
return count;
}
static DEVICE_ATTR(min_freq, S_IRUGO, ep93xx_pwm_get_min_freq, NULL);
static DEVICE_ATTR(max_freq, S_IRUGO, ep93xx_pwm_get_max_freq, NULL);
static DEVICE_ATTR(freq, S_IWUSR | S_IRUGO,
ep93xx_pwm_get_freq, ep93xx_pwm_set_freq);
static DEVICE_ATTR(duty_percent, S_IWUSR | S_IRUGO,
ep93xx_pwm_get_duty_percent, ep93xx_pwm_set_duty_percent);
static DEVICE_ATTR(invert, S_IWUSR | S_IRUGO,
ep93xx_pwm_get_invert, ep93xx_pwm_set_invert);
static struct attribute *ep93xx_pwm_attrs[] = {
&dev_attr_min_freq.attr,
&dev_attr_max_freq.attr,
&dev_attr_freq.attr,
&dev_attr_duty_percent.attr,
&dev_attr_invert.attr,
NULL
};
static const struct attribute_group ep93xx_pwm_sysfs_files = {
.attrs = ep93xx_pwm_attrs,
};
static int __init ep93xx_pwm_probe(struct platform_device *pdev)
{
struct ep93xx_pwm *pwm;
struct resource *res;
int err;
err = ep93xx_pwm_acquire_gpio(pdev);
if (err)
return err;
pwm = kzalloc(sizeof(struct ep93xx_pwm), GFP_KERNEL);
if (!pwm) {
err = -ENOMEM;
goto fail_no_mem;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res == NULL) {
err = -ENXIO;
goto fail_no_mem_resource;
}
res = request_mem_region(res->start, resource_size(res), pdev->name);
if (res == NULL) {
err = -EBUSY;
goto fail_no_mem_resource;
}
pwm->mmio_base = ioremap(res->start, resource_size(res));
if (pwm->mmio_base == NULL) {
err = -ENXIO;
goto fail_no_ioremap;
}
err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
if (err)
goto fail_no_sysfs;
pwm->clk = clk_get(&pdev->dev, "pwm_clk");
if (IS_ERR(pwm->clk)) {
err = PTR_ERR(pwm->clk);
goto fail_no_clk;
}
pwm->duty_percent = 50;
platform_set_drvdata(pdev, pwm);
/* disable pwm at startup. Avoids zero value. */
ep93xx_pwm_disable(pwm);
ep93xx_pwm_write_tc(pwm, EP93XX_PWM_MAX_COUNT);
ep93xx_pwm_write_dc(pwm, EP93XX_PWM_MAX_COUNT / 2);
clk_enable(pwm->clk);
return 0;
fail_no_clk:
sysfs_remove_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
fail_no_sysfs:
iounmap(pwm->mmio_base);
fail_no_ioremap:
release_mem_region(res->start, resource_size(res));
fail_no_mem_resource:
kfree(pwm);
fail_no_mem:
ep93xx_pwm_release_gpio(pdev);
return err;
}
static int __exit ep93xx_pwm_remove(struct platform_device *pdev)
{
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
ep93xx_pwm_disable(pwm);
clk_disable(pwm->clk);
clk_put(pwm->clk);
platform_set_drvdata(pdev, NULL);
sysfs_remove_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
iounmap(pwm->mmio_base);
release_mem_region(res->start, resource_size(res));
kfree(pwm);
ep93xx_pwm_release_gpio(pdev);
return 0;
}
static struct platform_driver ep93xx_pwm_driver = {
.driver = {
.name = "ep93xx-pwm",
.owner = THIS_MODULE,
},
.remove = __exit_p(ep93xx_pwm_remove),
};
module_platform_driver_probe(ep93xx_pwm_driver, ep93xx_pwm_probe);
MODULE_AUTHOR("Matthieu Crapet <mcrapet@gmail.com>, "
"H Hartley Sweeten <hsweeten@visionengravers.com>");
MODULE_DESCRIPTION("EP93xx PWM driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ep93xx-pwm");
|