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Commit a23086981723570c8952520d9ffaf6995d45f63e

Authored by H Hartley Sweeten
Committed by Thierry Reding
1 parent 8f43e18e27
Exists in smarc-imx_3.14.28_1.0.0_ga and in 1 other branch imx_3.14.28_1.0.0_ga

pwm: add ep93xx PWM support 

Remove the non-standard EP93xx PWM driver in drivers/misc and add
a new driver for the PWM controllers on the EP93xx platform based
on the PWM framework.

These PWM controllers each support 1 PWM channel with programmable
duty cycle, frequency, and polarity inversion.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <rmallon@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Showing 6 changed files with 240 additions and 300 deletions Side-by-side Diff

drivers/misc/Kconfig
Diff comments   View file @ a230869
... ... @@ -381,19 +381,6 @@
381 381 This driver provides support for the Honeywell HMC6352 compass,
382 382 providing configuration and heading data via sysfs.
383 383  
384   -config EP93XX_PWM
385   - tristate "EP93xx PWM support"
386   - depends on ARCH_EP93XX
387   - help
388   - This option enables device driver support for the PWM channels
389   - on the Cirrus EP93xx processors. The EP9307 chip only has one
390   - PWM channel all the others have two, the second channel is an
391   - alternate function of the EGPIO14 pin. A sysfs interface is
392   - provided to control the PWM channels.
393   -
394   - To compile this driver as a module, choose M here: the module will
395   - be called ep93xx_pwm.
396   -
397 384 config DS1682
398 385 tristate "Dallas DS1682 Total Elapsed Time Recorder with Alarm"
399 386 depends on I2C
drivers/misc/Makefile
Diff comments   View file @ a230869
... ... @@ -33,7 +33,6 @@
33 33 obj-$(CONFIG_ISL29003) += isl29003.o
34 34 obj-$(CONFIG_ISL29020) += isl29020.o
35 35 obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o
36   -obj-$(CONFIG_EP93XX_PWM) += ep93xx_pwm.o
37 36 obj-$(CONFIG_DS1682) += ds1682.o
38 37 obj-$(CONFIG_TI_DAC7512) += ti_dac7512.o
39 38 obj-$(CONFIG_C2PORT) += c2port/
drivers/misc/ep93xx_pwm.c
View file @ a230869
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>
22   -#include <linux/slab.h>
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   -/*
43   - * /sys/devices/platform/ep93xx-pwm.N
44   - * /min_freq read-only minimum pwm output frequency
45   - * /max_req read-only maximum pwm output frequency
46   - * /freq read-write pwm output frequency (0 = disable output)
47   - * /duty_percent read-write pwm duty cycle percent (1..99)
48   - * /invert read-write invert pwm output
49   - */
50   -
51   -static ssize_t ep93xx_pwm_get_min_freq(struct device *dev,
52   - struct device_attribute *attr, char *buf)
53   -{
54   - struct platform_device *pdev = to_platform_device(dev);
55   - struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
56   - unsigned long rate = clk_get_rate(pwm->clk);
57   -
58   - return sprintf(buf, "%ld\n", rate / (EP93XX_PWM_MAX_COUNT + 1));
59   -}
60   -
61   -static ssize_t ep93xx_pwm_get_max_freq(struct device *dev,
62   - struct device_attribute *attr, char *buf)
63   -{
64   - struct platform_device *pdev = to_platform_device(dev);
65   - struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
66   - unsigned long rate = clk_get_rate(pwm->clk);
67   -
68   - return sprintf(buf, "%ld\n", rate / 2);
69   -}
70   -
71   -static ssize_t ep93xx_pwm_get_freq(struct device *dev,
72   - struct device_attribute *attr, char *buf)
73   -{
74   - struct platform_device *pdev = to_platform_device(dev);
75   - struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
76   -
77   - if (readl(pwm->mmio_base + EP93XX_PWMx_ENABLE) & 0x1) {
78   - unsigned long rate = clk_get_rate(pwm->clk);
79   - u16 term = readl(pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
80   -
81   - return sprintf(buf, "%ld\n", rate / (term + 1));
82   - } else {
83   - return sprintf(buf, "disabled\n");
84   - }
85   -}
86   -
87   -static ssize_t ep93xx_pwm_set_freq(struct device *dev,
88   - struct device_attribute *attr, const char *buf, size_t count)
89   -{
90   - struct platform_device *pdev = to_platform_device(dev);
91   - struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
92   - long val;
93   - int err;
94   -
95   - err = kstrtol(buf, 10, &val);
96   - if (err)
97   - return -EINVAL;
98   -
99   - if (val == 0) {
100   - writel(0x0, pwm->mmio_base + EP93XX_PWMx_ENABLE);
101   - } else if (val <= (clk_get_rate(pwm->clk) / 2)) {
102   - u32 term, duty;
103   -
104   - val = (clk_get_rate(pwm->clk) / val) - 1;
105   - if (val > EP93XX_PWM_MAX_COUNT)
106   - val = EP93XX_PWM_MAX_COUNT;
107   - if (val < 1)
108   - val = 1;
109   -
110   - term = readl(pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
111   - duty = ((val + 1) * pwm->duty_percent / 100) - 1;
112   -
113   - /* If pwm is running, order is important */
114   - if (val > term) {
115   - writel(val, pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
116   - writel(duty, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
117   - } else {
118   - writel(duty, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
119   - writel(val, pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
120   - }
121   -
122   - if (!readl(pwm->mmio_base + EP93XX_PWMx_ENABLE) & 0x1)
123   - writel(0x1, pwm->mmio_base + EP93XX_PWMx_ENABLE);
124   - } else {
125   - return -EINVAL;
126   - }
127   -
128   - return count;
129   -}
130   -
131   -static ssize_t ep93xx_pwm_get_duty_percent(struct device *dev,
132   - struct device_attribute *attr, char *buf)
133   -{
134   - struct platform_device *pdev = to_platform_device(dev);
135   - struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
136   -
137   - return sprintf(buf, "%d\n", pwm->duty_percent);
138   -}
139   -
140   -static ssize_t ep93xx_pwm_set_duty_percent(struct device *dev,
141   - struct device_attribute *attr, const char *buf, size_t count)
142   -{
143   - struct platform_device *pdev = to_platform_device(dev);
144   - struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
145   - long val;
146   - int err;
147   -
148   - err = kstrtol(buf, 10, &val);
149   - if (err)
150   - return -EINVAL;
151   -
152   - if (val > 0 && val < 100) {
153   - u32 term = readl(pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
154   - u32 duty = ((term + 1) * val / 100) - 1;
155   -
156   - writel(duty, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
157   - pwm->duty_percent = val;
158   - return count;
159   - }
160   -
161   - return -EINVAL;
162   -}
163   -
164   -static ssize_t ep93xx_pwm_get_invert(struct device *dev,
165   - struct device_attribute *attr, char *buf)
166   -{
167   - struct platform_device *pdev = to_platform_device(dev);
168   - struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
169   - int inverted = readl(pwm->mmio_base + EP93XX_PWMx_INVERT) & 0x1;
170   -
171   - return sprintf(buf, "%d\n", inverted);
172   -}
173   -
174   -static ssize_t ep93xx_pwm_set_invert(struct device *dev,
175   - struct device_attribute *attr, const char *buf, size_t count)
176   -{
177   - struct platform_device *pdev = to_platform_device(dev);
178   - struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
179   - long val;
180   - int err;
181   -
182   - err = kstrtol(buf, 10, &val);
183   - if (err)
184   - return -EINVAL;
185   -
186   - if (val == 0)
187   - writel(0x0, pwm->mmio_base + EP93XX_PWMx_INVERT);
188   - else if (val == 1)
189   - writel(0x1, pwm->mmio_base + EP93XX_PWMx_INVERT);
190   - else
191   - return -EINVAL;
192   -
193   - return count;
194   -}
195   -
196   -static DEVICE_ATTR(min_freq, S_IRUGO, ep93xx_pwm_get_min_freq, NULL);
197   -static DEVICE_ATTR(max_freq, S_IRUGO, ep93xx_pwm_get_max_freq, NULL);
198   -static DEVICE_ATTR(freq, S_IWUSR | S_IRUGO,
199   - ep93xx_pwm_get_freq, ep93xx_pwm_set_freq);
200   -static DEVICE_ATTR(duty_percent, S_IWUSR | S_IRUGO,
201   - ep93xx_pwm_get_duty_percent, ep93xx_pwm_set_duty_percent);
202   -static DEVICE_ATTR(invert, S_IWUSR | S_IRUGO,
203   - ep93xx_pwm_get_invert, ep93xx_pwm_set_invert);
204   -
205   -static struct attribute *ep93xx_pwm_attrs[] = {
206   - &dev_attr_min_freq.attr,
207   - &dev_attr_max_freq.attr,
208   - &dev_attr_freq.attr,
209   - &dev_attr_duty_percent.attr,
210   - &dev_attr_invert.attr,
211   - NULL
212   -};
213   -
214   -static const struct attribute_group ep93xx_pwm_sysfs_files = {
215   - .attrs = ep93xx_pwm_attrs,
216   -};
217   -
218   -static int ep93xx_pwm_probe(struct platform_device *pdev)
219   -{
220   - struct ep93xx_pwm *pwm;
221   - struct resource *res;
222   - int ret;
223   -
224   - pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
225   - if (!pwm)
226   - return -ENOMEM;
227   -
228   - pwm->clk = devm_clk_get(&pdev->dev, "pwm_clk");
229   - if (IS_ERR(pwm->clk))
230   - return PTR_ERR(pwm->clk);
231   -
232   - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
233   - pwm->mmio_base = devm_ioremap_resource(&pdev->dev, res);
234   - if (IS_ERR(pwm->mmio_base))
235   - return PTR_ERR(pwm->mmio_base);
236   -
237   - ret = ep93xx_pwm_acquire_gpio(pdev);
238   - if (ret)
239   - return ret;
240   -
241   - ret = sysfs_create_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
242   - if (ret) {
243   - ep93xx_pwm_release_gpio(pdev);
244   - return ret;
245   - }
246   -
247   - pwm->duty_percent = 50;
248   -
249   - /* disable pwm at startup. Avoids zero value. */
250   - writel(0x0, pwm->mmio_base + EP93XX_PWMx_ENABLE);
251   - writel(EP93XX_PWM_MAX_COUNT, pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
252   - writel(EP93XX_PWM_MAX_COUNT/2, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
253   -
254   - clk_enable(pwm->clk);
255   -
256   - platform_set_drvdata(pdev, pwm);
257   - return 0;
258   -}
259   -
260   -static int ep93xx_pwm_remove(struct platform_device *pdev)
261   -{
262   - struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
263   -
264   - writel(0x0, pwm->mmio_base + EP93XX_PWMx_ENABLE);
265   - clk_disable(pwm->clk);
266   - sysfs_remove_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
267   - ep93xx_pwm_release_gpio(pdev);
268   -
269   - return 0;
270   -}
271   -
272   -static struct platform_driver ep93xx_pwm_driver = {
273   - .driver = {
274   - .name = "ep93xx-pwm",
275   - .owner = THIS_MODULE,
276   - },
277   - .probe = ep93xx_pwm_probe,
278   - .remove = ep93xx_pwm_remove,
279   -};
280   -module_platform_driver(ep93xx_pwm_driver);
281   -
282   -MODULE_AUTHOR("Matthieu Crapet <mcrapet@gmail.com>, "
283   - "H Hartley Sweeten <hsweeten@visionengravers.com>");
284   -MODULE_DESCRIPTION("EP93xx PWM driver");
285   -MODULE_LICENSE("GPL");
286   -MODULE_ALIAS("platform:ep93xx-pwm");
... ... @@ -62,6 +62,15 @@
62 62 To compile this driver as a module, choose M here: the module
63 63 will be called pwm-bfin.
64 64  
  65 +config PWM_EP93XX
  66 + tristate "Cirrus Logic EP93xx PWM support"
  67 + depends on ARCH_EP93XX
  68 + help
  69 + Generic PWM framework driver for Cirrus Logic EP93xx.
  70 +
  71 + To compile this driver as a module, choose M here: the module
  72 + will be called pwm-ep93xx.
  73 +
65 74 config PWM_IMX
66 75 tristate "i.MX PWM support"
67 76 depends on ARCH_MXC
drivers/pwm/Makefile
Diff comments   View file @ a230869
... ... @@ -3,6 +3,7 @@
3 3 obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o
4 4 obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o
5 5 obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
  6 +obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o
6 7 obj-$(CONFIG_PWM_IMX) += pwm-imx.o
7 8 obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o
8 9 obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o
drivers/pwm/pwm-ep93xx.c
Diff comments   View file @ a230869
  1 +/*
  2 + * PWM framework driver for Cirrus Logic EP93xx
  3 + *
  4 + * Copyright (c) 2009 Matthieu Crapet <mcrapet@gmail.com>
  5 + * Copyright (c) 2009, 2013 H Hartley Sweeten <hsweeten@visionengravers.com>
  6 + *
  7 + * EP9301/02 have only one channel:
  8 + * platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
  9 + *
  10 + * EP9307 has only one channel:
  11 + * platform device ep93xx-pwm.0 - PWMOUT
  12 + *
  13 + * EP9312/15 have two channels:
  14 + * platform device ep93xx-pwm.0 - PWMOUT
  15 + * platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
  16 + *
  17 + * This program is free software; you can redistribute it and/or
  18 + * modify it under the terms of the GNU General Public License
  19 + * as published by the Free Software Foundation; either version
  20 + * 2 of the License, or (at your option) any later version.
  21 + *
  22 + * This program is distributed in the hope that it will be useful,
  23 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  25 + * GNU General Public License for more details.
  26 + */
  27 +
  28 +#include <linux/module.h>
  29 +#include <linux/platform_device.h>
  30 +#include <linux/slab.h>
  31 +#include <linux/clk.h>
  32 +#include <linux/err.h>
  33 +#include <linux/io.h>
  34 +#include <linux/pwm.h>
  35 +
  36 +#include <asm/div64.h>
  37 +
  38 +#include <mach/platform.h> /* for ep93xx_pwm_{acquire,release}_gpio() */
  39 +
  40 +#define EP93XX_PWMx_TERM_COUNT 0x00
  41 +#define EP93XX_PWMx_DUTY_CYCLE 0x04
  42 +#define EP93XX_PWMx_ENABLE 0x08
  43 +#define EP93XX_PWMx_INVERT 0x0c
  44 +
  45 +struct ep93xx_pwm {
  46 + void __iomem *base;
  47 + struct clk *clk;
  48 + struct pwm_chip chip;
  49 +};
  50 +
  51 +static inline struct ep93xx_pwm *to_ep93xx_pwm(struct pwm_chip *chip)
  52 +{
  53 + return container_of(chip, struct ep93xx_pwm, chip);
  54 +}
  55 +
  56 +static int ep93xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
  57 +{
  58 + struct platform_device *pdev = to_platform_device(chip->dev);
  59 +
  60 + return ep93xx_pwm_acquire_gpio(pdev);
  61 +}
  62 +
  63 +static void ep93xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
  64 +{
  65 + struct platform_device *pdev = to_platform_device(chip->dev);
  66 +
  67 + ep93xx_pwm_release_gpio(pdev);
  68 +}
  69 +
  70 +static int ep93xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
  71 + int duty_ns, int period_ns)
  72 +{
  73 + struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
  74 + void __iomem *base = ep93xx_pwm->base;
  75 + unsigned long long c;
  76 + unsigned long period_cycles;
  77 + unsigned long duty_cycles;
  78 + unsigned long term;
  79 + int ret = 0;
  80 +
  81 + /*
  82 + * The clock needs to be enabled to access the PWM registers.
  83 + * Configuration can be changed at any time.
  84 + */
  85 + if (!test_bit(PWMF_ENABLED, &pwm->flags)) {
  86 + ret = clk_enable(ep93xx_pwm->clk);
  87 + if (ret)
  88 + return ret;
  89 + }
  90 +
  91 + c = clk_get_rate(ep93xx_pwm->clk);
  92 + c *= period_ns;
  93 + do_div(c, 1000000000);
  94 + period_cycles = c;
  95 +
  96 + c = period_cycles;
  97 + c *= duty_ns;
  98 + do_div(c, period_ns);
  99 + duty_cycles = c;
  100 +
  101 + if (period_cycles < 0x10000 && duty_cycles < 0x10000) {
  102 + term = readw(base + EP93XX_PWMx_TERM_COUNT);
  103 +
  104 + /* Order is important if PWM is running */
  105 + if (period_cycles > term) {
  106 + writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
  107 + writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
  108 + } else {
  109 + writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
  110 + writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
  111 + }
  112 + } else {
  113 + ret = -EINVAL;
  114 + }
  115 +
  116 + if (!test_bit(PWMF_ENABLED, &pwm->flags))
  117 + clk_disable(ep93xx_pwm->clk);
  118 +
  119 + return ret;
  120 +}
  121 +
  122 +static int ep93xx_pwm_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
  123 + enum pwm_polarity polarity)
  124 +{
  125 + struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
  126 + int ret;
  127 +
  128 + /*
  129 + * The clock needs to be enabled to access the PWM registers.
  130 + * Polarity can only be changed when the PWM is disabled.
  131 + */
  132 + ret = clk_enable(ep93xx_pwm->clk);
  133 + if (ret)
  134 + return ret;
  135 +
  136 + if (polarity == PWM_POLARITY_INVERSED)
  137 + writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_INVERT);
  138 + else
  139 + writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_INVERT);
  140 +
  141 + clk_disable(ep93xx_pwm->clk);
  142 +
  143 + return 0;
  144 +}
  145 +
  146 +static int ep93xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
  147 +{
  148 + struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
  149 + int ret;
  150 +
  151 + ret = clk_enable(ep93xx_pwm->clk);
  152 + if (ret)
  153 + return ret;
  154 +
  155 + writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);
  156 +
  157 + return 0;
  158 +}
  159 +
  160 +static void ep93xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
  161 +{
  162 + struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
  163 +
  164 + writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);
  165 + clk_disable(ep93xx_pwm->clk);
  166 +}
  167 +
  168 +static const struct pwm_ops ep93xx_pwm_ops = {
  169 + .request = ep93xx_pwm_request,
  170 + .free = ep93xx_pwm_free,
  171 + .config = ep93xx_pwm_config,
  172 + .set_polarity = ep93xx_pwm_polarity,
  173 + .enable = ep93xx_pwm_enable,
  174 + .disable = ep93xx_pwm_disable,
  175 + .owner = THIS_MODULE,
  176 +};
  177 +
  178 +static int ep93xx_pwm_probe(struct platform_device *pdev)
  179 +{
  180 + struct ep93xx_pwm *ep93xx_pwm;
  181 + struct resource *res;
  182 + int ret;
  183 +
  184 + ep93xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_pwm), GFP_KERNEL);
  185 + if (!ep93xx_pwm)
  186 + return -ENOMEM;
  187 +
  188 + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  189 + ep93xx_pwm->base = devm_ioremap_resource(&pdev->dev, res);
  190 + if (IS_ERR(ep93xx_pwm->base))
  191 + return PTR_ERR(ep93xx_pwm->base);
  192 +
  193 + ep93xx_pwm->clk = devm_clk_get(&pdev->dev, "pwm_clk");
  194 + if (IS_ERR(ep93xx_pwm->clk))
  195 + return PTR_ERR(ep93xx_pwm->clk);
  196 +
  197 + ep93xx_pwm->chip.dev = &pdev->dev;
  198 + ep93xx_pwm->chip.ops = &ep93xx_pwm_ops;
  199 + ep93xx_pwm->chip.base = -1;
  200 + ep93xx_pwm->chip.npwm = 1;
  201 +
  202 + ret = pwmchip_add(&ep93xx_pwm->chip);
  203 + if (ret < 0)
  204 + return ret;
  205 +
  206 + platform_set_drvdata(pdev, ep93xx_pwm);
  207 + return 0;
  208 +}
  209 +
  210 +static int ep93xx_pwm_remove(struct platform_device *pdev)
  211 +{
  212 + struct ep93xx_pwm *ep93xx_pwm = platform_get_drvdata(pdev);
  213 +
  214 + return pwmchip_remove(&ep93xx_pwm->chip);
  215 +}
  216 +
  217 +static struct platform_driver ep93xx_pwm_driver = {
  218 + .driver = {
  219 + .name = "ep93xx-pwm",
  220 + },
  221 + .probe = ep93xx_pwm_probe,
  222 + .remove = ep93xx_pwm_remove,
  223 +};
  224 +module_platform_driver(ep93xx_pwm_driver);
  225 +
  226 +MODULE_DESCRIPTION("Cirrus Logic EP93xx PWM driver");
  227 +MODULE_AUTHOR("Matthieu Crapet <mcrapet@gmail.com>, "
  228 + "H Hartley Sweeten <hsweeten@visionengravers.com>");
  229 +MODULE_ALIAS("platform:ep93xx-pwm");
  230 +MODULE_LICENSE("GPL");