Commit | Line | Data |
---|---|---|
aa958f57 LW |
1 | /* |
2 | * Copyright (C) 2007-2009 ST-Ericsson AB | |
3 | * License terms: GNU General Public License (GPL) version 2 | |
4 | * Real Time Clock interface for ST-Ericsson AB COH 901 331 RTC. | |
5 | * Author: Linus Walleij <linus.walleij@stericsson.com> | |
6 | * Based on rtc-pl031.c by Deepak Saxena <dsaxena@plexity.net> | |
7 | * Copyright 2006 (c) MontaVista Software, Inc. | |
8 | */ | |
9 | #include <linux/init.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/rtc.h> | |
12 | #include <linux/clk.h> | |
13 | #include <linux/interrupt.h> | |
14 | #include <linux/pm.h> | |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/io.h> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
aa958f57 LW |
18 | |
19 | /* | |
20 | * Registers in the COH 901 331 | |
21 | */ | |
22 | /* Alarm value 32bit (R/W) */ | |
23 | #define COH901331_ALARM 0x00U | |
24 | /* Used to set current time 32bit (R/W) */ | |
25 | #define COH901331_SET_TIME 0x04U | |
26 | /* Indication if current time is valid 32bit (R/-) */ | |
27 | #define COH901331_VALID 0x08U | |
28 | /* Read the current time 32bit (R/-) */ | |
29 | #define COH901331_CUR_TIME 0x0cU | |
30 | /* Event register for the "alarm" interrupt */ | |
31 | #define COH901331_IRQ_EVENT 0x10U | |
32 | /* Mask register for the "alarm" interrupt */ | |
33 | #define COH901331_IRQ_MASK 0x14U | |
34 | /* Force register for the "alarm" interrupt */ | |
35 | #define COH901331_IRQ_FORCE 0x18U | |
36 | ||
37 | /* | |
38 | * Reference to RTC block clock | |
39 | * Notice that the frequent clk_enable()/clk_disable() on this | |
40 | * clock is mainly to be able to turn on/off other clocks in the | |
41 | * hierarchy as needed, the RTC clock is always on anyway. | |
42 | */ | |
43 | struct coh901331_port { | |
44 | struct rtc_device *rtc; | |
45 | struct clk *clk; | |
aa958f57 LW |
46 | void __iomem *virtbase; |
47 | int irq; | |
62068e2c | 48 | #ifdef CONFIG_PM_SLEEP |
aa958f57 LW |
49 | u32 irqmaskstore; |
50 | #endif | |
51 | }; | |
52 | ||
53 | static irqreturn_t coh901331_interrupt(int irq, void *data) | |
54 | { | |
55 | struct coh901331_port *rtap = data; | |
56 | ||
57 | clk_enable(rtap->clk); | |
58 | /* Ack IRQ */ | |
59 | writel(1, rtap->virtbase + COH901331_IRQ_EVENT); | |
378ce74b LW |
60 | /* |
61 | * Disable the interrupt. This is necessary because | |
62 | * the RTC lives on a lower-clocked line and will | |
63 | * not release the IRQ line until after a few (slower) | |
64 | * clock cycles. The interrupt will be re-enabled when | |
65 | * a new alarm is set anyway. | |
66 | */ | |
67 | writel(0, rtap->virtbase + COH901331_IRQ_MASK); | |
aa958f57 | 68 | clk_disable(rtap->clk); |
378ce74b | 69 | |
aa958f57 LW |
70 | /* Set alarm flag */ |
71 | rtc_update_irq(rtap->rtc, 1, RTC_AF); | |
72 | ||
73 | return IRQ_HANDLED; | |
74 | } | |
75 | ||
76 | static int coh901331_read_time(struct device *dev, struct rtc_time *tm) | |
77 | { | |
78 | struct coh901331_port *rtap = dev_get_drvdata(dev); | |
79 | ||
80 | clk_enable(rtap->clk); | |
81 | /* Check if the time is valid */ | |
82 | if (readl(rtap->virtbase + COH901331_VALID)) { | |
83 | rtc_time_to_tm(readl(rtap->virtbase + COH901331_CUR_TIME), tm); | |
84 | clk_disable(rtap->clk); | |
85 | return rtc_valid_tm(tm); | |
86 | } | |
87 | clk_disable(rtap->clk); | |
88 | return -EINVAL; | |
89 | } | |
90 | ||
91 | static int coh901331_set_mmss(struct device *dev, unsigned long secs) | |
92 | { | |
93 | struct coh901331_port *rtap = dev_get_drvdata(dev); | |
94 | ||
95 | clk_enable(rtap->clk); | |
96 | writel(secs, rtap->virtbase + COH901331_SET_TIME); | |
97 | clk_disable(rtap->clk); | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
102 | static int coh901331_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) | |
103 | { | |
104 | struct coh901331_port *rtap = dev_get_drvdata(dev); | |
105 | ||
106 | clk_enable(rtap->clk); | |
107 | rtc_time_to_tm(readl(rtap->virtbase + COH901331_ALARM), &alarm->time); | |
108 | alarm->pending = readl(rtap->virtbase + COH901331_IRQ_EVENT) & 1U; | |
109 | alarm->enabled = readl(rtap->virtbase + COH901331_IRQ_MASK) & 1U; | |
110 | clk_disable(rtap->clk); | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | static int coh901331_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) | |
116 | { | |
117 | struct coh901331_port *rtap = dev_get_drvdata(dev); | |
118 | unsigned long time; | |
119 | ||
120 | rtc_tm_to_time(&alarm->time, &time); | |
121 | clk_enable(rtap->clk); | |
122 | writel(time, rtap->virtbase + COH901331_ALARM); | |
123 | writel(alarm->enabled, rtap->virtbase + COH901331_IRQ_MASK); | |
124 | clk_disable(rtap->clk); | |
125 | ||
126 | return 0; | |
127 | } | |
128 | ||
129 | static int coh901331_alarm_irq_enable(struct device *dev, unsigned int enabled) | |
130 | { | |
131 | struct coh901331_port *rtap = dev_get_drvdata(dev); | |
132 | ||
133 | clk_enable(rtap->clk); | |
134 | if (enabled) | |
135 | writel(1, rtap->virtbase + COH901331_IRQ_MASK); | |
136 | else | |
137 | writel(0, rtap->virtbase + COH901331_IRQ_MASK); | |
138 | clk_disable(rtap->clk); | |
378ce74b LW |
139 | |
140 | return 0; | |
aa958f57 LW |
141 | } |
142 | ||
143 | static struct rtc_class_ops coh901331_ops = { | |
144 | .read_time = coh901331_read_time, | |
145 | .set_mmss = coh901331_set_mmss, | |
146 | .read_alarm = coh901331_read_alarm, | |
147 | .set_alarm = coh901331_set_alarm, | |
148 | .alarm_irq_enable = coh901331_alarm_irq_enable, | |
149 | }; | |
150 | ||
151 | static int __exit coh901331_remove(struct platform_device *pdev) | |
152 | { | |
3a02893f | 153 | struct coh901331_port *rtap = platform_get_drvdata(pdev); |
aa958f57 | 154 | |
7fcbf5fd | 155 | if (rtap) |
8384dfeb | 156 | clk_unprepare(rtap->clk); |
aa958f57 LW |
157 | |
158 | return 0; | |
159 | } | |
160 | ||
161 | ||
162 | static int __init coh901331_probe(struct platform_device *pdev) | |
163 | { | |
164 | int ret; | |
165 | struct coh901331_port *rtap; | |
166 | struct resource *res; | |
167 | ||
36ac1d24 LW |
168 | rtap = devm_kzalloc(&pdev->dev, |
169 | sizeof(struct coh901331_port), GFP_KERNEL); | |
aa958f57 LW |
170 | if (!rtap) |
171 | return -ENOMEM; | |
172 | ||
173 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
daaf90f0 JH |
174 | rtap->virtbase = devm_ioremap_resource(&pdev->dev, res); |
175 | if (IS_ERR(rtap->virtbase)) | |
176 | return PTR_ERR(rtap->virtbase); | |
aa958f57 LW |
177 | |
178 | rtap->irq = platform_get_irq(pdev, 0); | |
36ac1d24 LW |
179 | if (devm_request_irq(&pdev->dev, rtap->irq, coh901331_interrupt, 0, |
180 | "RTC COH 901 331 Alarm", rtap)) | |
181 | return -EIO; | |
aa958f57 | 182 | |
3b759d7f | 183 | rtap->clk = devm_clk_get(&pdev->dev, NULL); |
aa958f57 LW |
184 | if (IS_ERR(rtap->clk)) { |
185 | ret = PTR_ERR(rtap->clk); | |
186 | dev_err(&pdev->dev, "could not get clock\n"); | |
36ac1d24 | 187 | return ret; |
aa958f57 LW |
188 | } |
189 | ||
190 | /* We enable/disable the clock only to assure it works */ | |
8384dfeb | 191 | ret = clk_prepare_enable(rtap->clk); |
aa958f57 LW |
192 | if (ret) { |
193 | dev_err(&pdev->dev, "could not enable clock\n"); | |
3b759d7f | 194 | return ret; |
aa958f57 LW |
195 | } |
196 | clk_disable(rtap->clk); | |
197 | ||
9cf3b5fa | 198 | platform_set_drvdata(pdev, rtap); |
94b60dba JH |
199 | rtap->rtc = devm_rtc_device_register(&pdev->dev, "coh901331", |
200 | &coh901331_ops, THIS_MODULE); | |
aa958f57 LW |
201 | if (IS_ERR(rtap->rtc)) { |
202 | ret = PTR_ERR(rtap->rtc); | |
203 | goto out_no_rtc; | |
204 | } | |
205 | ||
aa958f57 LW |
206 | return 0; |
207 | ||
208 | out_no_rtc: | |
8384dfeb | 209 | clk_unprepare(rtap->clk); |
aa958f57 LW |
210 | return ret; |
211 | } | |
212 | ||
62068e2c JH |
213 | #ifdef CONFIG_PM_SLEEP |
214 | static int coh901331_suspend(struct device *dev) | |
aa958f57 | 215 | { |
62068e2c | 216 | struct coh901331_port *rtap = dev_get_drvdata(dev); |
aa958f57 LW |
217 | |
218 | /* | |
219 | * If this RTC alarm will be used for waking the system up, | |
220 | * don't disable it of course. Else we just disable the alarm | |
221 | * and await suspension. | |
222 | */ | |
62068e2c | 223 | if (device_may_wakeup(dev)) { |
aa958f57 LW |
224 | enable_irq_wake(rtap->irq); |
225 | } else { | |
226 | clk_enable(rtap->clk); | |
227 | rtap->irqmaskstore = readl(rtap->virtbase + COH901331_IRQ_MASK); | |
228 | writel(0, rtap->virtbase + COH901331_IRQ_MASK); | |
229 | clk_disable(rtap->clk); | |
230 | } | |
8384dfeb | 231 | clk_unprepare(rtap->clk); |
aa958f57 LW |
232 | return 0; |
233 | } | |
234 | ||
62068e2c | 235 | static int coh901331_resume(struct device *dev) |
aa958f57 | 236 | { |
62068e2c | 237 | struct coh901331_port *rtap = dev_get_drvdata(dev); |
aa958f57 | 238 | |
8384dfeb | 239 | clk_prepare(rtap->clk); |
62068e2c | 240 | if (device_may_wakeup(dev)) { |
aa958f57 | 241 | disable_irq_wake(rtap->irq); |
5a98c04d | 242 | } else { |
aa958f57 LW |
243 | clk_enable(rtap->clk); |
244 | writel(rtap->irqmaskstore, rtap->virtbase + COH901331_IRQ_MASK); | |
245 | clk_disable(rtap->clk); | |
5a98c04d | 246 | } |
aa958f57 LW |
247 | return 0; |
248 | } | |
aa958f57 LW |
249 | #endif |
250 | ||
62068e2c JH |
251 | static SIMPLE_DEV_PM_OPS(coh901331_pm_ops, coh901331_suspend, coh901331_resume); |
252 | ||
aa958f57 LW |
253 | static void coh901331_shutdown(struct platform_device *pdev) |
254 | { | |
3a02893f | 255 | struct coh901331_port *rtap = platform_get_drvdata(pdev); |
aa958f57 LW |
256 | |
257 | clk_enable(rtap->clk); | |
258 | writel(0, rtap->virtbase + COH901331_IRQ_MASK); | |
828296de | 259 | clk_disable_unprepare(rtap->clk); |
aa958f57 LW |
260 | } |
261 | ||
a16b6c63 LW |
262 | static const struct of_device_id coh901331_dt_match[] = { |
263 | { .compatible = "stericsson,coh901331" }, | |
264 | {}, | |
265 | }; | |
73798d5c | 266 | MODULE_DEVICE_TABLE(of, coh901331_dt_match); |
a16b6c63 | 267 | |
aa958f57 LW |
268 | static struct platform_driver coh901331_driver = { |
269 | .driver = { | |
270 | .name = "rtc-coh901331", | |
62068e2c | 271 | .pm = &coh901331_pm_ops, |
a16b6c63 | 272 | .of_match_table = coh901331_dt_match, |
aa958f57 LW |
273 | }, |
274 | .remove = __exit_p(coh901331_remove), | |
aa958f57 LW |
275 | .shutdown = coh901331_shutdown, |
276 | }; | |
277 | ||
4fdf7a9f | 278 | module_platform_driver_probe(coh901331_driver, coh901331_probe); |
aa958f57 LW |
279 | |
280 | MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>"); | |
281 | MODULE_DESCRIPTION("ST-Ericsson AB COH 901 331 RTC Driver"); | |
282 | MODULE_LICENSE("GPL"); |