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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>
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
45struct ep93xx_pwm {
46 void __iomem *base;
47 struct clk *clk;
48 struct pwm_chip chip;
49};
50
51static inline struct ep93xx_pwm *to_ep93xx_pwm(struct pwm_chip *chip)
52{
53 return container_of(chip, struct ep93xx_pwm, chip);
54}
55
56static 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
63static 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
70static 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
83
84
85 if (!pwm_is_enabled(pwm)) {
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
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 (!pwm_is_enabled(pwm))
117 clk_disable(ep93xx_pwm->clk);
118
119 return ret;
120}
121
122static 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
130
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
146static 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
160static 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
168static 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
178static 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
210static 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
217static struct platform_driver ep93xx_pwm_driver = {
218 .driver = {
219 .name = "ep93xx-pwm",
220 },
221 .probe = ep93xx_pwm_probe,
222 .remove = ep93xx_pwm_remove,
223};
224module_platform_driver(ep93xx_pwm_driver);
225
226MODULE_DESCRIPTION("Cirrus Logic EP93xx PWM driver");
227MODULE_AUTHOR("Matthieu Crapet <mcrapet@gmail.com>");
228MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
229MODULE_ALIAS("platform:ep93xx-pwm");
230MODULE_LICENSE("GPL");
231
