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1 | /* |
2 | * Backup battery driver for Wolfson Microelectronics wm831x PMICs | |
3 | * | |
4 | * Copyright 2009 Wolfson Microelectronics PLC. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
12 | #include <linux/err.h> | |
13 | #include <linux/platform_device.h> | |
14 | #include <linux/power_supply.h> | |
5a0e3ad6 | 15 | #include <linux/slab.h> |
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16 | |
17 | #include <linux/mfd/wm831x/core.h> | |
18 | #include <linux/mfd/wm831x/auxadc.h> | |
19 | #include <linux/mfd/wm831x/pmu.h> | |
20 | #include <linux/mfd/wm831x/pdata.h> | |
21 | ||
22 | struct wm831x_backup { | |
23 | struct wm831x *wm831x; | |
24 | struct power_supply backup; | |
d0376031 | 25 | char name[20]; |
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26 | }; |
27 | ||
28 | static int wm831x_backup_read_voltage(struct wm831x *wm831x, | |
29 | enum wm831x_auxadc src, | |
30 | union power_supply_propval *val) | |
31 | { | |
32 | int ret; | |
33 | ||
34 | ret = wm831x_auxadc_read_uv(wm831x, src); | |
35 | if (ret >= 0) | |
36 | val->intval = ret; | |
37 | ||
38 | return ret; | |
39 | } | |
40 | ||
41 | /********************************************************************* | |
42 | * Backup supply properties | |
43 | *********************************************************************/ | |
44 | ||
45 | static void wm831x_config_backup(struct wm831x *wm831x) | |
46 | { | |
47 | struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data; | |
48 | struct wm831x_backup_pdata *pdata; | |
49 | int ret, reg; | |
50 | ||
51 | if (!wm831x_pdata || !wm831x_pdata->backup) { | |
52 | dev_warn(wm831x->dev, | |
53 | "No backup battery charger configuration\n"); | |
54 | return; | |
55 | } | |
56 | ||
57 | pdata = wm831x_pdata->backup; | |
58 | ||
59 | reg = 0; | |
60 | ||
61 | if (pdata->charger_enable) | |
62 | reg |= WM831X_BKUP_CHG_ENA | WM831X_BKUP_BATT_DET_ENA; | |
63 | if (pdata->no_constant_voltage) | |
64 | reg |= WM831X_BKUP_CHG_MODE; | |
65 | ||
66 | switch (pdata->vlim) { | |
67 | case 2500: | |
68 | break; | |
69 | case 3100: | |
70 | reg |= WM831X_BKUP_CHG_VLIM; | |
71 | break; | |
72 | default: | |
73 | dev_err(wm831x->dev, "Invalid backup voltage limit %dmV\n", | |
74 | pdata->vlim); | |
75 | } | |
76 | ||
77 | switch (pdata->ilim) { | |
78 | case 100: | |
79 | break; | |
80 | case 200: | |
81 | reg |= 1; | |
82 | break; | |
83 | case 300: | |
84 | reg |= 2; | |
85 | break; | |
86 | case 400: | |
87 | reg |= 3; | |
88 | break; | |
89 | default: | |
90 | dev_err(wm831x->dev, "Invalid backup current limit %duA\n", | |
91 | pdata->ilim); | |
92 | } | |
93 | ||
94 | ret = wm831x_reg_unlock(wm831x); | |
95 | if (ret != 0) { | |
96 | dev_err(wm831x->dev, "Failed to unlock registers: %d\n", ret); | |
97 | return; | |
98 | } | |
99 | ||
100 | ret = wm831x_set_bits(wm831x, WM831X_BACKUP_CHARGER_CONTROL, | |
101 | WM831X_BKUP_CHG_ENA_MASK | | |
102 | WM831X_BKUP_CHG_MODE_MASK | | |
103 | WM831X_BKUP_BATT_DET_ENA_MASK | | |
104 | WM831X_BKUP_CHG_VLIM_MASK | | |
105 | WM831X_BKUP_CHG_ILIM_MASK, | |
106 | reg); | |
107 | if (ret != 0) | |
108 | dev_err(wm831x->dev, | |
109 | "Failed to set backup charger config: %d\n", ret); | |
110 | ||
111 | wm831x_reg_lock(wm831x); | |
112 | } | |
113 | ||
114 | static int wm831x_backup_get_prop(struct power_supply *psy, | |
115 | enum power_supply_property psp, | |
116 | union power_supply_propval *val) | |
117 | { | |
118 | struct wm831x_backup *devdata = dev_get_drvdata(psy->dev->parent); | |
119 | struct wm831x *wm831x = devdata->wm831x; | |
120 | int ret = 0; | |
121 | ||
122 | ret = wm831x_reg_read(wm831x, WM831X_BACKUP_CHARGER_CONTROL); | |
123 | if (ret < 0) | |
124 | return ret; | |
125 | ||
126 | switch (psp) { | |
127 | case POWER_SUPPLY_PROP_STATUS: | |
128 | if (ret & WM831X_BKUP_CHG_STS) | |
129 | val->intval = POWER_SUPPLY_STATUS_CHARGING; | |
130 | else | |
131 | val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; | |
132 | break; | |
133 | ||
134 | case POWER_SUPPLY_PROP_VOLTAGE_NOW: | |
135 | ret = wm831x_backup_read_voltage(wm831x, WM831X_AUX_BKUP_BATT, | |
136 | val); | |
137 | break; | |
138 | ||
139 | case POWER_SUPPLY_PROP_PRESENT: | |
140 | if (ret & WM831X_BKUP_CHG_STS) | |
141 | val->intval = 1; | |
142 | else | |
143 | val->intval = 0; | |
144 | break; | |
145 | ||
146 | default: | |
147 | ret = -EINVAL; | |
148 | break; | |
149 | } | |
150 | ||
151 | return ret; | |
152 | } | |
153 | ||
154 | static enum power_supply_property wm831x_backup_props[] = { | |
155 | POWER_SUPPLY_PROP_STATUS, | |
156 | POWER_SUPPLY_PROP_VOLTAGE_NOW, | |
157 | POWER_SUPPLY_PROP_PRESENT, | |
158 | }; | |
159 | ||
160 | /********************************************************************* | |
161 | * Initialisation | |
162 | *********************************************************************/ | |
163 | ||
c8afa640 | 164 | static int wm831x_backup_probe(struct platform_device *pdev) |
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165 | { |
166 | struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); | |
d0376031 | 167 | struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data; |
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168 | struct wm831x_backup *devdata; |
169 | struct power_supply *backup; | |
0e19dbb7 | 170 | int ret; |
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171 | |
172 | devdata = kzalloc(sizeof(struct wm831x_backup), GFP_KERNEL); | |
173 | if (devdata == NULL) | |
174 | return -ENOMEM; | |
175 | ||
176 | devdata->wm831x = wm831x; | |
177 | platform_set_drvdata(pdev, devdata); | |
178 | ||
179 | backup = &devdata->backup; | |
180 | ||
181 | /* We ignore configuration failures since we can still read | |
182 | * back the status without enabling the charger (which may | |
183 | * already be enabled anyway). | |
184 | */ | |
185 | wm831x_config_backup(wm831x); | |
186 | ||
d0376031 MB |
187 | if (wm831x_pdata && wm831x_pdata->wm831x_num) |
188 | snprintf(devdata->name, sizeof(devdata->name), | |
189 | "wm831x-backup.%d", wm831x_pdata->wm831x_num); | |
190 | else | |
191 | snprintf(devdata->name, sizeof(devdata->name), | |
192 | "wm831x-backup"); | |
193 | ||
194 | backup->name = devdata->name; | |
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195 | backup->type = POWER_SUPPLY_TYPE_BATTERY; |
196 | backup->properties = wm831x_backup_props; | |
197 | backup->num_properties = ARRAY_SIZE(wm831x_backup_props); | |
198 | backup->get_property = wm831x_backup_get_prop; | |
199 | ret = power_supply_register(&pdev->dev, backup); | |
200 | if (ret) | |
201 | goto err_kmalloc; | |
202 | ||
203 | return ret; | |
204 | ||
205 | err_kmalloc: | |
206 | kfree(devdata); | |
207 | return ret; | |
208 | } | |
209 | ||
415ec69f | 210 | static int wm831x_backup_remove(struct platform_device *pdev) |
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211 | { |
212 | struct wm831x_backup *devdata = platform_get_drvdata(pdev); | |
213 | ||
214 | power_supply_unregister(&devdata->backup); | |
d0376031 | 215 | kfree(devdata->backup.name); |
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216 | kfree(devdata); |
217 | ||
218 | return 0; | |
219 | } | |
220 | ||
221 | static struct platform_driver wm831x_backup_driver = { | |
222 | .probe = wm831x_backup_probe, | |
28ea73f4 | 223 | .remove = wm831x_backup_remove, |
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224 | .driver = { |
225 | .name = "wm831x-backup", | |
226 | }, | |
227 | }; | |
228 | ||
300bac7f | 229 | module_platform_driver(wm831x_backup_driver); |
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230 | |
231 | MODULE_DESCRIPTION("Backup battery charger driver for WM831x PMICs"); | |
232 | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); | |
233 | MODULE_LICENSE("GPL"); | |
234 | MODULE_ALIAS("platform:wm831x-backup"); |