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x86: Fix false positive section mismatch warnings in the apic code
[linux-2.6/verdex.git] / arch / arm / plat-mxc / pwm.c
blob9bffbc507cc2804e79dcdde527e9ad55ef67ba2c
1 /*
2 * simple driver for PWM (Pulse Width Modulator) controller
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * Derived from pxa PWM driver by eric miao <eric.miao@marvell.com>
9 */
10
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/platform_device.h>
14 #include <linux/err.h>
15 #include <linux/clk.h>
16 #include <linux/io.h>
17 #include <linux/pwm.h>
18
19 #if defined CONFIG_ARCH_MX1 || defined CONFIG_ARCH_MX21
20 #define PWM_VER_1
21
22 #define PWMCR 0x00 /* PWM Control Register */
23 #define PWMSR 0x04 /* PWM Sample Register */
24 #define PWMPR 0x08 /* PWM Period Register */
25 #define PWMCNR 0x0C /* PWM Counter Register */
26
27 #define PWMCR_HCTR (1 << 18) /* Halfword FIFO Data Swapping */
28 #define PWMCR_BCTR (1 << 17) /* Byte FIFO Data Swapping */
29 #define PWMCR_SWR (1 << 16) /* Software Reset */
30 #define PWMCR_CLKSRC_PERCLK (0 << 15) /* PERCLK Clock Source */
31 #define PWMCR_CLKSRC_CLK32 (1 << 15) /* 32KHz Clock Source */
32 #define PWMCR_PRESCALER(x) (((x - 1) & 0x7F) << 8) /* PRESCALER */
33 #define PWMCR_IRQ (1 << 7) /* Interrupt Request */
34 #define PWMCR_IRQEN (1 << 6) /* Interrupt Request Enable */
35 #define PWMCR_FIFOAV (1 << 5) /* FIFO Available */
36 #define PWMCR_EN (1 << 4) /* Enables/Disables the PWM */
37 #define PWMCR_REPEAT(x) (((x) & 0x03) << 2) /* Sample Repeats */
38 #define PWMCR_DIV(x) (((x) & 0x03) << 0) /* Clock divider 2/4/8/16 */
39
40 #define MAX_DIV (128 * 16)
41 #endif
42
43 #if defined CONFIG_MACH_MX27 || defined CONFIG_ARCH_MX31
44 #define PWM_VER_2
45
46 #define PWMCR 0x00 /* PWM Control Register */
47 #define PWMSR 0x04 /* PWM Status Register */
48 #define PWMIR 0x08 /* PWM Interrupt Register */
49 #define PWMSAR 0x0C /* PWM Sample Register */
50 #define PWMPR 0x10 /* PWM Period Register */
51 #define PWMCNR 0x14 /* PWM Counter Register */
52
53 #define PWMCR_EN (1 << 0) /* Enables/Disables the PWM */
54 #define PWMCR_REPEAT(x) (((x) & 0x03) << 1) /* Sample Repeats */
55 #define PWMCR_SWR (1 << 3) /* Software Reset */
56 #define PWMCR_PRESCALER(x) (((x - 1) & 0xFFF) << 4)/* PRESCALER */
57 #define PWMCR_CLKSRC(x) (((x) & 0x3) << 16)
58 #define PWMCR_CLKSRC_OFF (0 << 16)
59 #define PWMCR_CLKSRC_IPG (1 << 16)
60 #define PWMCR_CLKSRC_IPG_HIGH (2 << 16)
61 #define PWMCR_CLKSRC_CLK32 (3 << 16)
62 #define PWMCR_POUTC
63 #define PWMCR_HCTR (1 << 20) /* Halfword FIFO Data Swapping */
64 #define PWMCR_BCTR (1 << 21) /* Byte FIFO Data Swapping */
65 #define PWMCR_DBGEN (1 << 22) /* Debug Mode */
66 #define PWMCR_WAITEN (1 << 23) /* Wait Mode */
67 #define PWMCR_DOZEN (1 << 24) /* Doze Mode */
68 #define PWMCR_STOPEN (1 << 25) /* Stop Mode */
69 #define PWMCR_FWM(x) (((x) & 0x3) << 26) /* FIFO Water Mark */
70
71 #define MAX_DIV 4096
72 #endif
73
74 #define PWMS_SAMPLE(x) ((x) & 0xFFFF) /* Contains a two-sample word */
75 #define PWMP_PERIOD(x) ((x) & 0xFFFF) /* Represents the PWM's period */
76 #define PWMC_COUNTER(x) ((x) & 0xFFFF) /* Represents the current count value */
77
78 struct pwm_device {
79 struct list_head node;
80 struct platform_device *pdev;
81
82 const char *label;
83 struct clk *clk;
84
85 int clk_enabled;
86 void __iomem *mmio_base;
87
88 unsigned int use_count;
89 unsigned int pwm_id;
90 };
91
92 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
93 {
94 unsigned long long c;
95 unsigned long period_cycles, duty_cycles, prescale;
96
97 if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
98 return -EINVAL;
99
100 c = clk_get_rate(pwm->clk);
101 c = c * period_ns;
102 do_div(c, 1000000000);
103 period_cycles = c;
104
105 prescale = period_cycles / 0x10000 + 1;
106
107 period_cycles /= prescale;
108 c = (unsigned long long)period_cycles * duty_ns;
109 do_div(c, period_ns);
110 duty_cycles = c;
111
112 #ifdef PWM_VER_2
113 writel(duty_cycles, pwm->mmio_base + PWMSAR);
114 writel(period_cycles, pwm->mmio_base + PWMPR);
115 writel(PWMCR_PRESCALER(prescale - 1) | PWMCR_CLKSRC_IPG_HIGH | PWMCR_EN,
116 pwm->mmio_base + PWMCR);
117 #elif defined PWM_VER_1
118 #error PWM not yet working on MX1 / MX21
119 #endif
120
121 return 0;
122 }
123 EXPORT_SYMBOL(pwm_config);
124
125 int pwm_enable(struct pwm_device *pwm)
126 {
127 int rc = 0;
128
129 if (!pwm->clk_enabled) {
130 rc = clk_enable(pwm->clk);
131 if (!rc)
132 pwm->clk_enabled = 1;
133 }
134 return rc;
135 }
136 EXPORT_SYMBOL(pwm_enable);
137
138 void pwm_disable(struct pwm_device *pwm)
139 {
140 if (pwm->clk_enabled) {
141 clk_disable(pwm->clk);
142 pwm->clk_enabled = 0;
143 }
144 }
145 EXPORT_SYMBOL(pwm_disable);
146
147 static DEFINE_MUTEX(pwm_lock);
148 static LIST_HEAD(pwm_list);
149
150 struct pwm_device *pwm_request(int pwm_id, const char *label)
151 {
152 struct pwm_device *pwm;
153 int found = 0;
154
155 mutex_lock(&pwm_lock);
156
157 list_for_each_entry(pwm, &pwm_list, node) {
158 if (pwm->pwm_id == pwm_id) {
159 found = 1;
160 break;
161 }
162 }
163
164 if (found) {
165 if (pwm->use_count == 0) {
166 pwm->use_count++;
167 pwm->label = label;
168 } else
169 pwm = ERR_PTR(-EBUSY);
170 } else
171 pwm = ERR_PTR(-ENOENT);
172
173 mutex_unlock(&pwm_lock);
174 return pwm;
175 }
176 EXPORT_SYMBOL(pwm_request);
177
178 void pwm_free(struct pwm_device *pwm)
179 {
180 mutex_lock(&pwm_lock);
181
182 if (pwm->use_count) {
183 pwm->use_count--;
184 pwm->label = NULL;
185 } else
186 pr_warning("PWM device already freed\n");
187
188 mutex_unlock(&pwm_lock);
189 }
190 EXPORT_SYMBOL(pwm_free);
191
192 static int __devinit mxc_pwm_probe(struct platform_device *pdev)
193 {
194 struct pwm_device *pwm;
195 struct resource *r;
196 int ret = 0;
197
198 pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
199 if (pwm == NULL) {
200 dev_err(&pdev->dev, "failed to allocate memory\n");
201 return -ENOMEM;
202 }
203
204 pwm->clk = clk_get(&pdev->dev, "pwm");
205
206 if (IS_ERR(pwm->clk)) {
207 ret = PTR_ERR(pwm->clk);
208 goto err_free;
209 }
210
211 pwm->clk_enabled = 0;
212
213 pwm->use_count = 0;
214 pwm->pwm_id = pdev->id;
215 pwm->pdev = pdev;
216
217 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
218 if (r == NULL) {
219 dev_err(&pdev->dev, "no memory resource defined\n");
220 ret = -ENODEV;
221 goto err_free_clk;
222 }
223
224 r = request_mem_region(r->start, r->end - r->start + 1, pdev->name);
225 if (r == NULL) {
226 dev_err(&pdev->dev, "failed to request memory resource\n");
227 ret = -EBUSY;
228 goto err_free_clk;
229 }
230
231 pwm->mmio_base = ioremap(r->start, r->end - r->start + 1);
232 if (pwm->mmio_base == NULL) {
233 dev_err(&pdev->dev, "failed to ioremap() registers\n");
234 ret = -ENODEV;
235 goto err_free_mem;
236 }
237
238 mutex_lock(&pwm_lock);
239 list_add_tail(&pwm->node, &pwm_list);
240 mutex_unlock(&pwm_lock);
241
242 platform_set_drvdata(pdev, pwm);
243 return 0;
244
245 err_free_mem:
246 release_mem_region(r->start, r->end - r->start + 1);
247 err_free_clk:
248 clk_put(pwm->clk);
249 err_free:
250 kfree(pwm);
251 return ret;
252 }
253
254 static int __devexit mxc_pwm_remove(struct platform_device *pdev)
255 {
256 struct pwm_device *pwm;
257 struct resource *r;
258
259 pwm = platform_get_drvdata(pdev);
260 if (pwm == NULL)
261 return -ENODEV;
262
263 mutex_lock(&pwm_lock);
264 list_del(&pwm->node);
265 mutex_unlock(&pwm_lock);
266
267 iounmap(pwm->mmio_base);
268
269 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
270 release_mem_region(r->start, r->end - r->start + 1);
271
272 clk_put(pwm->clk);
273
274 kfree(pwm);
275 return 0;
276 }
277
278 static struct platform_driver mxc_pwm_driver = {
279 .driver = {
280 .name = "mxc_pwm",
281 },
282 .probe = mxc_pwm_probe,
283 .remove = __devexit_p(mxc_pwm_remove),
284 };
285
286 static int __init mxc_pwm_init(void)
287 {
288 return platform_driver_register(&mxc_pwm_driver);
289 }
290 arch_initcall(mxc_pwm_init);
291
292 static void __exit mxc_pwm_exit(void)
293 {
294 platform_driver_unregister(&mxc_pwm_driver);
295 }
296 module_exit(mxc_pwm_exit);
297
298 MODULE_LICENSE("GPL v2");
299 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
300
Verdex Pro support