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14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/platform_device.h>
17#include <linux/slab.h>
18#include <linux/err.h>
19#include <linux/clk.h>
20#include <linux/io.h>
21#include <linux/pwm.h>
22
23#include <asm/div64.h>
24
25#define HAS_SECONDARY_PWM 0x10
26#define PWM_ID_BASE(d) ((d) & 0xf)
27
28static const struct platform_device_id pwm_id_table[] = {
29
30 { "pxa25x-pwm", 0 },
31 { "pxa27x-pwm", 0 | HAS_SECONDARY_PWM },
32 { "pxa168-pwm", 1 },
33 { "pxa910-pwm", 1 },
34 { },
35};
36MODULE_DEVICE_TABLE(platform, pwm_id_table);
37
38
39#define PWMCR (0x00)
40#define PWMDCR (0x04)
41#define PWMPCR (0x08)
42
43#define PWMCR_SD (1 << 6)
44#define PWMDCR_FD (1 << 10)
45
46struct pxa_pwm_chip {
47 struct pwm_chip chip;
48 struct device *dev;
49
50 struct clk *clk;
51 int clk_enabled;
52 void __iomem *mmio_base;
53};
54
55static inline struct pxa_pwm_chip *to_pxa_pwm_chip(struct pwm_chip *chip)
56{
57 return container_of(chip, struct pxa_pwm_chip, chip);
58}
59
60
61
62
63
64static int pxa_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
65 int duty_ns, int period_ns)
66{
67 struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
68 unsigned long long c;
69 unsigned long period_cycles, prescale, pv, dc;
70 unsigned long offset;
71 int rc;
72
73 offset = pwm->hwpwm ? 0x10 : 0;
74
75 c = clk_get_rate(pc->clk);
76 c = c * period_ns;
77 do_div(c, 1000000000);
78 period_cycles = c;
79
80 if (period_cycles < 1)
81 period_cycles = 1;
82 prescale = (period_cycles - 1) / 1024;
83 pv = period_cycles / (prescale + 1) - 1;
84
85 if (prescale > 63)
86 return -EINVAL;
87
88 if (duty_ns == period_ns)
89 dc = PWMDCR_FD;
90 else
91 dc = (pv + 1) * duty_ns / period_ns;
92
93
94
95
96 rc = clk_prepare_enable(pc->clk);
97 if (rc < 0)
98 return rc;
99
100 writel(prescale, pc->mmio_base + offset + PWMCR);
101 writel(dc, pc->mmio_base + offset + PWMDCR);
102 writel(pv, pc->mmio_base + offset + PWMPCR);
103
104 clk_disable_unprepare(pc->clk);
105 return 0;
106}
107
108static int pxa_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
109{
110 struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
111 int rc = 0;
112
113 if (!pc->clk_enabled) {
114 rc = clk_prepare_enable(pc->clk);
115 if (!rc)
116 pc->clk_enabled++;
117 }
118 return rc;
119}
120
121static void pxa_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
122{
123 struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
124
125 if (pc->clk_enabled) {
126 clk_disable_unprepare(pc->clk);
127 pc->clk_enabled--;
128 }
129}
130
131static struct pwm_ops pxa_pwm_ops = {
132 .config = pxa_pwm_config,
133 .enable = pxa_pwm_enable,
134 .disable = pxa_pwm_disable,
135 .owner = THIS_MODULE,
136};
137
138static int __devinit pwm_probe(struct platform_device *pdev)
139{
140 const struct platform_device_id *id = platform_get_device_id(pdev);
141 struct pxa_pwm_chip *pwm;
142 struct resource *r;
143 int ret = 0;
144
145 pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
146 if (pwm == NULL) {
147 dev_err(&pdev->dev, "failed to allocate memory\n");
148 return -ENOMEM;
149 }
150
151 pwm->clk = devm_clk_get(&pdev->dev, NULL);
152 if (IS_ERR(pwm->clk))
153 return PTR_ERR(pwm->clk);
154
155 pwm->clk_enabled = 0;
156
157 pwm->chip.dev = &pdev->dev;
158 pwm->chip.ops = &pxa_pwm_ops;
159 pwm->chip.base = -1;
160 pwm->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1;
161
162 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
163 if (r == NULL) {
164 dev_err(&pdev->dev, "no memory resource defined\n");
165 return -ENODEV;
166 }
167
168 pwm->mmio_base = devm_request_and_ioremap(&pdev->dev, r);
169 if (pwm->mmio_base == NULL)
170 return -EADDRNOTAVAIL;
171
172 ret = pwmchip_add(&pwm->chip);
173 if (ret < 0) {
174 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
175 return ret;
176 }
177
178 platform_set_drvdata(pdev, pwm);
179 return 0;
180}
181
182static int __devexit pwm_remove(struct platform_device *pdev)
183{
184 struct pxa_pwm_chip *chip;
185
186 chip = platform_get_drvdata(pdev);
187 if (chip == NULL)
188 return -ENODEV;
189
190 return pwmchip_remove(&chip->chip);
191}
192
193static struct platform_driver pwm_driver = {
194 .driver = {
195 .name = "pxa25x-pwm",
196 .owner = THIS_MODULE,
197 },
198 .probe = pwm_probe,
199 .remove = __devexit_p(pwm_remove),
200 .id_table = pwm_id_table,
201};
202
203static int __init pwm_init(void)
204{
205 return platform_driver_register(&pwm_driver);
206}
207arch_initcall(pwm_init);
208
209static void __exit pwm_exit(void)
210{
211 platform_driver_unregister(&pwm_driver);
212}
213module_exit(pwm_exit);
214
215MODULE_LICENSE("GPL v2");
216
