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43299f28 UKK |
1 | /* |
2 | * Real Time Clock driver for Freescale MC13783 PMIC | |
3 | * | |
4 | * (C) 2009 Sascha Hauer, Pengutronix | |
5 | * (C) 2009 Uwe Kleine-Koenig, Pengutronix | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include <linux/mfd/mc13783.h> | |
13 | #include <linux/platform_device.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/rtc.h> | |
17 | ||
18 | #define DRIVER_NAME "mc13783-rtc" | |
19 | ||
20 | #define MC13783_RTCTOD 20 | |
21 | #define MC13783_RTCTODA 21 | |
22 | #define MC13783_RTCDAY 22 | |
23 | #define MC13783_RTCDAYA 23 | |
24 | ||
25 | struct mc13783_rtc { | |
26 | struct rtc_device *rtc; | |
27 | struct mc13783 *mc13783; | |
28 | int valid; | |
29 | }; | |
30 | ||
31 | static int mc13783_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
32 | { | |
33 | struct mc13783_rtc *priv = dev_get_drvdata(dev); | |
34 | unsigned int seconds, days1, days2; | |
35 | unsigned long s1970; | |
36 | int ret; | |
37 | ||
38 | mc13783_lock(priv->mc13783); | |
39 | ||
40 | if (!priv->valid) { | |
41 | ret = -ENODATA; | |
42 | goto out; | |
43 | } | |
44 | ||
45 | ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days1); | |
46 | if (unlikely(ret)) | |
47 | goto out; | |
48 | ||
49 | ret = mc13783_reg_read(priv->mc13783, MC13783_RTCTOD, &seconds); | |
50 | if (unlikely(ret)) | |
51 | goto out; | |
52 | ||
53 | ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days2); | |
54 | out: | |
55 | mc13783_unlock(priv->mc13783); | |
56 | ||
57 | if (ret) | |
58 | return ret; | |
59 | ||
60 | if (days2 == days1 + 1) { | |
61 | if (seconds >= 86400 / 2) | |
62 | days2 = days1; | |
63 | else | |
64 | days1 = days2; | |
65 | } | |
66 | ||
67 | if (days1 != days2) | |
68 | return -EIO; | |
69 | ||
70 | s1970 = days1 * 86400 + seconds; | |
71 | ||
72 | rtc_time_to_tm(s1970, tm); | |
73 | ||
74 | return rtc_valid_tm(tm); | |
75 | } | |
76 | ||
77 | static int mc13783_rtc_set_mmss(struct device *dev, unsigned long secs) | |
78 | { | |
79 | struct mc13783_rtc *priv = dev_get_drvdata(dev); | |
80 | unsigned int seconds, days; | |
81 | int ret; | |
82 | ||
83 | seconds = secs % 86400; | |
84 | days = secs / 86400; | |
85 | ||
86 | mc13783_lock(priv->mc13783); | |
87 | ||
88 | /* | |
89 | * first write seconds=0 to prevent a day switch between writing days | |
90 | * and seconds below | |
91 | */ | |
92 | ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTOD, 0); | |
93 | if (unlikely(ret)) | |
94 | goto out; | |
95 | ||
96 | ret = mc13783_reg_write(priv->mc13783, MC13783_RTCDAY, days); | |
97 | if (unlikely(ret)) | |
98 | goto out; | |
99 | ||
100 | ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTOD, seconds); | |
101 | if (unlikely(ret)) | |
102 | goto out; | |
103 | ||
104 | ret = mc13783_ackirq(priv->mc13783, MC13783_IRQ_RTCRST); | |
105 | if (unlikely(ret)) | |
106 | goto out; | |
107 | ||
108 | ret = mc13783_unmask(priv->mc13783, MC13783_IRQ_RTCRST); | |
109 | out: | |
110 | priv->valid = !ret; | |
111 | ||
112 | mc13783_unlock(priv->mc13783); | |
113 | ||
114 | return ret; | |
115 | } | |
116 | ||
117 | static irqreturn_t mc13783_rtc_update_handler(int irq, void *dev) | |
118 | { | |
119 | struct mc13783_rtc *priv = dev; | |
120 | struct mc13783 *mc13783 = priv->mc13783; | |
121 | ||
122 | dev_dbg(&priv->rtc->dev, "1HZ\n"); | |
123 | ||
124 | rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_UF); | |
125 | ||
126 | mc13783_ackirq(mc13783, irq); | |
127 | ||
128 | return IRQ_HANDLED; | |
129 | } | |
130 | ||
131 | static int mc13783_rtc_update_irq_enable(struct device *dev, | |
132 | unsigned int enabled) | |
133 | { | |
134 | struct mc13783_rtc *priv = dev_get_drvdata(dev); | |
135 | int ret = -ENODATA; | |
136 | ||
137 | mc13783_lock(priv->mc13783); | |
138 | if (!priv->valid) | |
139 | goto out; | |
140 | ||
141 | ret = (enabled ? mc13783_unmask : mc13783_mask)(priv->mc13783, | |
142 | MC13783_IRQ_1HZ); | |
143 | out: | |
144 | mc13783_unlock(priv->mc13783); | |
145 | ||
146 | return ret; | |
147 | } | |
148 | ||
149 | static const struct rtc_class_ops mc13783_rtc_ops = { | |
150 | .read_time = mc13783_rtc_read_time, | |
151 | .set_mmss = mc13783_rtc_set_mmss, | |
152 | .update_irq_enable = mc13783_rtc_update_irq_enable, | |
153 | }; | |
154 | ||
155 | static irqreturn_t mc13783_rtc_reset_handler(int irq, void *dev) | |
156 | { | |
157 | struct mc13783_rtc *priv = dev; | |
158 | struct mc13783 *mc13783 = priv->mc13783; | |
159 | ||
160 | dev_dbg(&priv->rtc->dev, "RTCRST\n"); | |
161 | priv->valid = 0; | |
162 | ||
163 | mc13783_mask(mc13783, irq); | |
164 | ||
165 | return IRQ_HANDLED; | |
166 | } | |
167 | ||
168 | static int __devinit mc13783_rtc_probe(struct platform_device *pdev) | |
169 | { | |
170 | int ret; | |
171 | struct mc13783_rtc *priv; | |
172 | ||
173 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
174 | if (!priv) | |
175 | return -ENOMEM; | |
176 | ||
177 | priv->mc13783 = dev_get_drvdata(pdev->dev.parent); | |
178 | platform_set_drvdata(pdev, priv); | |
179 | ||
180 | priv->valid = 1; | |
181 | ||
182 | mc13783_lock(priv->mc13783); | |
183 | ||
184 | ret = mc13783_irq_request(priv->mc13783, MC13783_IRQ_RTCRST, | |
185 | mc13783_rtc_reset_handler, DRIVER_NAME, priv); | |
186 | if (ret) | |
187 | goto err_reset_irq_request; | |
188 | ||
189 | ret = mc13783_irq_request_nounmask(priv->mc13783, MC13783_IRQ_1HZ, | |
190 | mc13783_rtc_update_handler, DRIVER_NAME, priv); | |
191 | if (ret) | |
192 | goto err_update_irq_request; | |
193 | ||
194 | mc13783_unlock(priv->mc13783); | |
195 | ||
196 | priv->rtc = rtc_device_register(pdev->name, | |
197 | &pdev->dev, &mc13783_rtc_ops, THIS_MODULE); | |
198 | ||
199 | if (IS_ERR(priv->rtc)) { | |
200 | ret = PTR_ERR(priv->rtc); | |
201 | ||
202 | mc13783_lock(priv->mc13783); | |
203 | ||
204 | mc13783_irq_free(priv->mc13783, MC13783_IRQ_1HZ, priv); | |
205 | err_update_irq_request: | |
206 | ||
207 | mc13783_irq_free(priv->mc13783, MC13783_IRQ_RTCRST, priv); | |
208 | err_reset_irq_request: | |
209 | ||
210 | mc13783_unlock(priv->mc13783); | |
211 | ||
212 | platform_set_drvdata(pdev, NULL); | |
213 | kfree(priv); | |
214 | } | |
215 | ||
216 | return ret; | |
217 | } | |
218 | ||
219 | static int __devexit mc13783_rtc_remove(struct platform_device *pdev) | |
220 | { | |
221 | struct mc13783_rtc *priv = platform_get_drvdata(pdev); | |
222 | ||
223 | rtc_device_unregister(priv->rtc); | |
224 | ||
225 | mc13783_lock(priv->mc13783); | |
226 | ||
227 | mc13783_irq_free(priv->mc13783, MC13783_IRQ_1HZ, priv); | |
228 | mc13783_irq_free(priv->mc13783, MC13783_IRQ_RTCRST, priv); | |
229 | ||
230 | mc13783_unlock(priv->mc13783); | |
231 | ||
232 | platform_set_drvdata(pdev, NULL); | |
233 | ||
234 | kfree(priv); | |
235 | ||
236 | return 0; | |
237 | } | |
238 | ||
239 | static struct platform_driver mc13783_rtc_driver = { | |
240 | .remove = __devexit_p(mc13783_rtc_remove), | |
241 | .driver = { | |
242 | .name = DRIVER_NAME, | |
243 | .owner = THIS_MODULE, | |
244 | }, | |
245 | }; | |
246 | ||
247 | static int __init mc13783_rtc_init(void) | |
248 | { | |
249 | return platform_driver_probe(&mc13783_rtc_driver, &mc13783_rtc_probe); | |
250 | } | |
251 | module_init(mc13783_rtc_init); | |
252 | ||
253 | static void __exit mc13783_rtc_exit(void) | |
254 | { | |
255 | platform_driver_unregister(&mc13783_rtc_driver); | |
256 | } | |
257 | module_exit(mc13783_rtc_exit); | |
258 | ||
259 | MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); | |
260 | MODULE_DESCRIPTION("RTC driver for Freescale MC13783 PMIC"); | |
261 | MODULE_LICENSE("GPL v2"); | |
262 | MODULE_ALIAS("platform:" DRIVER_NAME); |