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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#include <mach/hardware.h>
19
20
21
22
23#define MX1_PWMC 0x00
24#define MX1_PWMS 0x04
25#define MX1_PWMP 0x08
26
27
28
29
30#define MX3_PWMCR 0x00
31#define MX3_PWMSAR 0x0C
32#define MX3_PWMPR 0x10
33#define MX3_PWMCR_PRESCALER(x) (((x - 1) & 0xFFF) << 4)
34#define MX3_PWMCR_CLKSRC_IPG_HIGH (2 << 16)
35#define MX3_PWMCR_CLKSRC_IPG (1 << 16)
36#define MX3_PWMCR_EN (1 << 0)
37
38
39
40struct pwm_device {
41 struct list_head node;
42 struct platform_device *pdev;
43
44 const char *label;
45 struct clk *clk;
46
47 int clk_enabled;
48 void __iomem *mmio_base;
49
50 unsigned int use_count;
51 unsigned int pwm_id;
52};
53
54int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
55{
56 if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
57 return -EINVAL;
58
59 if (cpu_is_mx27() || cpu_is_mx3() || cpu_is_mx25()) {
60 unsigned long long c;
61 unsigned long period_cycles, duty_cycles, prescale;
62 u32 cr;
63
64 c = clk_get_rate(pwm->clk);
65 c = c * period_ns;
66 do_div(c, 1000000000);
67 period_cycles = c;
68
69 prescale = period_cycles / 0x10000 + 1;
70
71 period_cycles /= prescale;
72 c = (unsigned long long)period_cycles * duty_ns;
73 do_div(c, period_ns);
74 duty_cycles = c;
75
76 writel(duty_cycles, pwm->mmio_base + MX3_PWMSAR);
77 writel(period_cycles, pwm->mmio_base + MX3_PWMPR);
78
79 cr = MX3_PWMCR_PRESCALER(prescale) | MX3_PWMCR_EN;
80
81 if (cpu_is_mx25())
82 cr |= MX3_PWMCR_CLKSRC_IPG;
83 else
84 cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;
85
86 writel(cr, pwm->mmio_base + MX3_PWMCR);
87 } else if (cpu_is_mx1() || cpu_is_mx21()) {
88
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103
104 u32 max = readl(pwm->mmio_base + MX1_PWMP);
105 u32 p = max * duty_ns / period_ns;
106 writel(max - p, pwm->mmio_base + MX1_PWMS);
107 } else {
108 BUG();
109 }
110
111 return 0;
112}
113EXPORT_SYMBOL(pwm_config);
114
115int pwm_enable(struct pwm_device *pwm)
116{
117 int rc = 0;
118
119 if (!pwm->clk_enabled) {
120 rc = clk_enable(pwm->clk);
121 if (!rc)
122 pwm->clk_enabled = 1;
123 }
124 return rc;
125}
126EXPORT_SYMBOL(pwm_enable);
127
128void pwm_disable(struct pwm_device *pwm)
129{
130 writel(0, pwm->mmio_base + MX3_PWMCR);
131
132 if (pwm->clk_enabled) {
133 clk_disable(pwm->clk);
134 pwm->clk_enabled = 0;
135 }
136}
137EXPORT_SYMBOL(pwm_disable);
138
139static DEFINE_MUTEX(pwm_lock);
140static LIST_HEAD(pwm_list);
141
142struct pwm_device *pwm_request(int pwm_id, const char *label)
143{
144 struct pwm_device *pwm;
145 int found = 0;
146
147 mutex_lock(&pwm_lock);
148
149 list_for_each_entry(pwm, &pwm_list, node) {
150 if (pwm->pwm_id == pwm_id) {
151 found = 1;
152 break;
153 }
154 }
155
156 if (found) {
157 if (pwm->use_count == 0) {
158 pwm->use_count++;
159 pwm->label = label;
160 } else
161 pwm = ERR_PTR(-EBUSY);
162 } else
163 pwm = ERR_PTR(-ENOENT);
164
165 mutex_unlock(&pwm_lock);
166 return pwm;
167}
168EXPORT_SYMBOL(pwm_request);
169
170void pwm_free(struct pwm_device *pwm)
171{
172 mutex_lock(&pwm_lock);
173
174 if (pwm->use_count) {
175 pwm->use_count--;
176 pwm->label = NULL;
177 } else
178 pr_warning("PWM device already freed\n");
179
180 mutex_unlock(&pwm_lock);
181}
182EXPORT_SYMBOL(pwm_free);
183
184static int __devinit mxc_pwm_probe(struct platform_device *pdev)
185{
186 struct pwm_device *pwm;
187 struct resource *r;
188 int ret = 0;
189
190 pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
191 if (pwm == NULL) {
192 dev_err(&pdev->dev, "failed to allocate memory\n");
193 return -ENOMEM;
194 }
195
196 pwm->clk = clk_get(&pdev->dev, "pwm");
197
198 if (IS_ERR(pwm->clk)) {
199 ret = PTR_ERR(pwm->clk);
200 goto err_free;
201 }
202
203 pwm->clk_enabled = 0;
204
205 pwm->use_count = 0;
206 pwm->pwm_id = pdev->id;
207 pwm->pdev = pdev;
208
209 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
210 if (r == NULL) {
211 dev_err(&pdev->dev, "no memory resource defined\n");
212 ret = -ENODEV;
213 goto err_free_clk;
214 }
215
216 r = request_mem_region(r->start, r->end - r->start + 1, pdev->name);
217 if (r == NULL) {
218 dev_err(&pdev->dev, "failed to request memory resource\n");
219 ret = -EBUSY;
220 goto err_free_clk;
221 }
222
223 pwm->mmio_base = ioremap(r->start, r->end - r->start + 1);
224 if (pwm->mmio_base == NULL) {
225 dev_err(&pdev->dev, "failed to ioremap() registers\n");
226 ret = -ENODEV;
227 goto err_free_mem;
228 }
229
230 mutex_lock(&pwm_lock);
231 list_add_tail(&pwm->node, &pwm_list);
232 mutex_unlock(&pwm_lock);
233
234 platform_set_drvdata(pdev, pwm);
235 return 0;
236
237err_free_mem:
238 release_mem_region(r->start, r->end - r->start + 1);
239err_free_clk:
240 clk_put(pwm->clk);
241err_free:
242 kfree(pwm);
243 return ret;
244}
245
246static int __devexit mxc_pwm_remove(struct platform_device *pdev)
247{
248 struct pwm_device *pwm;
249 struct resource *r;
250
251 pwm = platform_get_drvdata(pdev);
252 if (pwm == NULL)
253 return -ENODEV;
254
255 mutex_lock(&pwm_lock);
256 list_del(&pwm->node);
257 mutex_unlock(&pwm_lock);
258
259 iounmap(pwm->mmio_base);
260
261 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
262 release_mem_region(r->start, r->end - r->start + 1);
263
264 clk_put(pwm->clk);
265
266 kfree(pwm);
267 return 0;
268}
269
270static struct platform_driver mxc_pwm_driver = {
271 .driver = {
272 .name = "mxc_pwm",
273 },
274 .probe = mxc_pwm_probe,
275 .remove = __devexit_p(mxc_pwm_remove),
276};
277
278static int __init mxc_pwm_init(void)
279{
280 return platform_driver_register(&mxc_pwm_driver);
281}
282arch_initcall(mxc_pwm_init);
283
284static void __exit mxc_pwm_exit(void)
285{
286 platform_driver_unregister(&mxc_pwm_driver);
287}
288module_exit(mxc_pwm_exit);
289
290MODULE_LICENSE("GPL v2");
291MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
292
