Root/
1 | /* |
2 | * System monitoring driver for DA9052 PMICs. |
3 | * |
4 | * Copyright(c) 2012 Dialog Semiconductor Ltd. |
5 | * |
6 | * Author: Anthony Olech <Anthony.Olech@diasemi.com> |
7 | * |
8 | * This program is free software; you can redistribute it and/or modify |
9 | * it under the terms of the GNU General Public License as published by |
10 | * the Free Software Foundation; either version 2 of the License, or |
11 | * (at your option) any later version. |
12 | * |
13 | */ |
14 | |
15 | #include <linux/module.h> |
16 | #include <linux/delay.h> |
17 | #include <linux/uaccess.h> |
18 | #include <linux/platform_device.h> |
19 | #include <linux/time.h> |
20 | #include <linux/watchdog.h> |
21 | #include <linux/types.h> |
22 | #include <linux/kernel.h> |
23 | #include <linux/jiffies.h> |
24 | |
25 | #include <linux/mfd/da9052/reg.h> |
26 | #include <linux/mfd/da9052/da9052.h> |
27 | |
28 | #define DA9052_DEF_TIMEOUT 4 |
29 | #define DA9052_TWDMIN 256 |
30 | |
31 | struct da9052_wdt_data { |
32 | struct watchdog_device wdt; |
33 | struct da9052 *da9052; |
34 | struct kref kref; |
35 | unsigned long jpast; |
36 | }; |
37 | |
38 | static const struct { |
39 | u8 reg_val; |
40 | int time; /* Seconds */ |
41 | } da9052_wdt_maps[] = { |
42 | { 1, 2 }, |
43 | { 2, 4 }, |
44 | { 3, 8 }, |
45 | { 4, 16 }, |
46 | { 5, 32 }, |
47 | { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */ |
48 | { 6, 65 }, |
49 | { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */ |
50 | { 7, 131 }, |
51 | }; |
52 | |
53 | |
54 | static void da9052_wdt_release_resources(struct kref *r) |
55 | { |
56 | } |
57 | |
58 | static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev, |
59 | unsigned int timeout) |
60 | { |
61 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); |
62 | struct da9052 *da9052 = driver_data->da9052; |
63 | int ret, i; |
64 | |
65 | /* |
66 | * Disable the Watchdog timer before setting |
67 | * new time out. |
68 | */ |
69 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, |
70 | DA9052_CONTROLD_TWDSCALE, 0); |
71 | if (ret < 0) { |
72 | dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n", |
73 | ret); |
74 | return ret; |
75 | } |
76 | if (timeout) { |
77 | /* |
78 | * To change the timeout, da9052 needs to |
79 | * be disabled for at least 150 us. |
80 | */ |
81 | udelay(150); |
82 | |
83 | /* Set the desired timeout */ |
84 | for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++) |
85 | if (da9052_wdt_maps[i].time == timeout) |
86 | break; |
87 | |
88 | if (i == ARRAY_SIZE(da9052_wdt_maps)) |
89 | ret = -EINVAL; |
90 | else |
91 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, |
92 | DA9052_CONTROLD_TWDSCALE, |
93 | da9052_wdt_maps[i].reg_val); |
94 | if (ret < 0) { |
95 | dev_err(da9052->dev, |
96 | "Failed to update timescale bit, %d\n", ret); |
97 | return ret; |
98 | } |
99 | |
100 | wdt_dev->timeout = timeout; |
101 | driver_data->jpast = jiffies; |
102 | } |
103 | |
104 | return 0; |
105 | } |
106 | |
107 | static void da9052_wdt_ref(struct watchdog_device *wdt_dev) |
108 | { |
109 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); |
110 | |
111 | kref_get(&driver_data->kref); |
112 | } |
113 | |
114 | static void da9052_wdt_unref(struct watchdog_device *wdt_dev) |
115 | { |
116 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); |
117 | |
118 | kref_put(&driver_data->kref, da9052_wdt_release_resources); |
119 | } |
120 | |
121 | static int da9052_wdt_start(struct watchdog_device *wdt_dev) |
122 | { |
123 | return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout); |
124 | } |
125 | |
126 | static int da9052_wdt_stop(struct watchdog_device *wdt_dev) |
127 | { |
128 | return da9052_wdt_set_timeout(wdt_dev, 0); |
129 | } |
130 | |
131 | static int da9052_wdt_ping(struct watchdog_device *wdt_dev) |
132 | { |
133 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); |
134 | struct da9052 *da9052 = driver_data->da9052; |
135 | unsigned long msec, jnow = jiffies; |
136 | int ret; |
137 | |
138 | /* |
139 | * We have a minimum time for watchdog window called TWDMIN. A write |
140 | * to the watchdog before this elapsed time should cause an error. |
141 | */ |
142 | msec = (jnow - driver_data->jpast) * 1000/HZ; |
143 | if (msec < DA9052_TWDMIN) |
144 | mdelay(msec); |
145 | |
146 | /* Reset the watchdog timer */ |
147 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, |
148 | DA9052_CONTROLD_WATCHDOG, 1 << 7); |
149 | if (ret < 0) |
150 | goto err_strobe; |
151 | |
152 | /* |
153 | * FIXME: Reset the watchdog core, in general PMIC |
154 | * is supposed to do this |
155 | */ |
156 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, |
157 | DA9052_CONTROLD_WATCHDOG, 0 << 7); |
158 | err_strobe: |
159 | return ret; |
160 | } |
161 | |
162 | static struct watchdog_info da9052_wdt_info = { |
163 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, |
164 | .identity = "DA9052 Watchdog", |
165 | }; |
166 | |
167 | static const struct watchdog_ops da9052_wdt_ops = { |
168 | .owner = THIS_MODULE, |
169 | .start = da9052_wdt_start, |
170 | .stop = da9052_wdt_stop, |
171 | .ping = da9052_wdt_ping, |
172 | .set_timeout = da9052_wdt_set_timeout, |
173 | .ref = da9052_wdt_ref, |
174 | .unref = da9052_wdt_unref, |
175 | }; |
176 | |
177 | |
178 | static int da9052_wdt_probe(struct platform_device *pdev) |
179 | { |
180 | struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent); |
181 | struct da9052_wdt_data *driver_data; |
182 | struct watchdog_device *da9052_wdt; |
183 | int ret; |
184 | |
185 | driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data), |
186 | GFP_KERNEL); |
187 | if (!driver_data) { |
188 | dev_err(da9052->dev, "Unable to alloacate watchdog device\n"); |
189 | ret = -ENOMEM; |
190 | goto err; |
191 | } |
192 | driver_data->da9052 = da9052; |
193 | |
194 | da9052_wdt = &driver_data->wdt; |
195 | |
196 | da9052_wdt->timeout = DA9052_DEF_TIMEOUT; |
197 | da9052_wdt->info = &da9052_wdt_info; |
198 | da9052_wdt->ops = &da9052_wdt_ops; |
199 | watchdog_set_drvdata(da9052_wdt, driver_data); |
200 | |
201 | kref_init(&driver_data->kref); |
202 | |
203 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, |
204 | DA9052_CONTROLD_TWDSCALE, 0); |
205 | if (ret < 0) { |
206 | dev_err(&pdev->dev, "Failed to disable watchdog bits, %d\n", |
207 | ret); |
208 | goto err; |
209 | } |
210 | |
211 | ret = watchdog_register_device(&driver_data->wdt); |
212 | if (ret != 0) { |
213 | dev_err(da9052->dev, "watchdog_register_device() failed: %d\n", |
214 | ret); |
215 | goto err; |
216 | } |
217 | |
218 | dev_set_drvdata(&pdev->dev, driver_data); |
219 | err: |
220 | return ret; |
221 | } |
222 | |
223 | static int da9052_wdt_remove(struct platform_device *pdev) |
224 | { |
225 | struct da9052_wdt_data *driver_data = dev_get_drvdata(&pdev->dev); |
226 | |
227 | watchdog_unregister_device(&driver_data->wdt); |
228 | kref_put(&driver_data->kref, da9052_wdt_release_resources); |
229 | |
230 | return 0; |
231 | } |
232 | |
233 | static struct platform_driver da9052_wdt_driver = { |
234 | .probe = da9052_wdt_probe, |
235 | .remove = da9052_wdt_remove, |
236 | .driver = { |
237 | .name = "da9052-watchdog", |
238 | }, |
239 | }; |
240 | |
241 | module_platform_driver(da9052_wdt_driver); |
242 | |
243 | MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>"); |
244 | MODULE_DESCRIPTION("DA9052 SM Device Driver"); |
245 | MODULE_LICENSE("GPL"); |
246 | MODULE_ALIAS("platform:da9052-watchdog"); |
247 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9