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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; | |
297d716f KK |
24 | struct power_supply *backup; |
25 | struct power_supply_desc backup_desc; | |
d0376031 | 26 | char name[20]; |
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27 | }; |
28 | ||
29 | static int wm831x_backup_read_voltage(struct wm831x *wm831x, | |
30 | enum wm831x_auxadc src, | |
31 | union power_supply_propval *val) | |
32 | { | |
33 | int ret; | |
34 | ||
35 | ret = wm831x_auxadc_read_uv(wm831x, src); | |
36 | if (ret >= 0) | |
37 | val->intval = ret; | |
38 | ||
39 | return ret; | |
40 | } | |
41 | ||
42 | /********************************************************************* | |
43 | * Backup supply properties | |
44 | *********************************************************************/ | |
45 | ||
46 | static void wm831x_config_backup(struct wm831x *wm831x) | |
47 | { | |
48 | struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data; | |
49 | struct wm831x_backup_pdata *pdata; | |
50 | int ret, reg; | |
51 | ||
52 | if (!wm831x_pdata || !wm831x_pdata->backup) { | |
53 | dev_warn(wm831x->dev, | |
54 | "No backup battery charger configuration\n"); | |
55 | return; | |
56 | } | |
57 | ||
58 | pdata = wm831x_pdata->backup; | |
59 | ||
60 | reg = 0; | |
61 | ||
62 | if (pdata->charger_enable) | |
63 | reg |= WM831X_BKUP_CHG_ENA | WM831X_BKUP_BATT_DET_ENA; | |
64 | if (pdata->no_constant_voltage) | |
65 | reg |= WM831X_BKUP_CHG_MODE; | |
66 | ||
67 | switch (pdata->vlim) { | |
68 | case 2500: | |
69 | break; | |
70 | case 3100: | |
71 | reg |= WM831X_BKUP_CHG_VLIM; | |
72 | break; | |
73 | default: | |
74 | dev_err(wm831x->dev, "Invalid backup voltage limit %dmV\n", | |
75 | pdata->vlim); | |
76 | } | |
77 | ||
78 | switch (pdata->ilim) { | |
79 | case 100: | |
80 | break; | |
81 | case 200: | |
82 | reg |= 1; | |
83 | break; | |
84 | case 300: | |
85 | reg |= 2; | |
86 | break; | |
87 | case 400: | |
88 | reg |= 3; | |
89 | break; | |
90 | default: | |
91 | dev_err(wm831x->dev, "Invalid backup current limit %duA\n", | |
92 | pdata->ilim); | |
93 | } | |
94 | ||
95 | ret = wm831x_reg_unlock(wm831x); | |
96 | if (ret != 0) { | |
97 | dev_err(wm831x->dev, "Failed to unlock registers: %d\n", ret); | |
98 | return; | |
99 | } | |
100 | ||
101 | ret = wm831x_set_bits(wm831x, WM831X_BACKUP_CHARGER_CONTROL, | |
102 | WM831X_BKUP_CHG_ENA_MASK | | |
103 | WM831X_BKUP_CHG_MODE_MASK | | |
104 | WM831X_BKUP_BATT_DET_ENA_MASK | | |
105 | WM831X_BKUP_CHG_VLIM_MASK | | |
106 | WM831X_BKUP_CHG_ILIM_MASK, | |
107 | reg); | |
108 | if (ret != 0) | |
109 | dev_err(wm831x->dev, | |
110 | "Failed to set backup charger config: %d\n", ret); | |
111 | ||
112 | wm831x_reg_lock(wm831x); | |
113 | } | |
114 | ||
115 | static int wm831x_backup_get_prop(struct power_supply *psy, | |
116 | enum power_supply_property psp, | |
117 | union power_supply_propval *val) | |
118 | { | |
297d716f | 119 | struct wm831x_backup *devdata = dev_get_drvdata(psy->dev.parent); |
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120 | struct wm831x *wm831x = devdata->wm831x; |
121 | int ret = 0; | |
122 | ||
123 | ret = wm831x_reg_read(wm831x, WM831X_BACKUP_CHARGER_CONTROL); | |
124 | if (ret < 0) | |
125 | return ret; | |
126 | ||
127 | switch (psp) { | |
128 | case POWER_SUPPLY_PROP_STATUS: | |
129 | if (ret & WM831X_BKUP_CHG_STS) | |
130 | val->intval = POWER_SUPPLY_STATUS_CHARGING; | |
131 | else | |
132 | val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; | |
133 | break; | |
134 | ||
135 | case POWER_SUPPLY_PROP_VOLTAGE_NOW: | |
136 | ret = wm831x_backup_read_voltage(wm831x, WM831X_AUX_BKUP_BATT, | |
137 | val); | |
138 | break; | |
139 | ||
140 | case POWER_SUPPLY_PROP_PRESENT: | |
141 | if (ret & WM831X_BKUP_CHG_STS) | |
142 | val->intval = 1; | |
143 | else | |
144 | val->intval = 0; | |
145 | break; | |
146 | ||
147 | default: | |
148 | ret = -EINVAL; | |
149 | break; | |
150 | } | |
151 | ||
152 | return ret; | |
153 | } | |
154 | ||
155 | static enum power_supply_property wm831x_backup_props[] = { | |
156 | POWER_SUPPLY_PROP_STATUS, | |
157 | POWER_SUPPLY_PROP_VOLTAGE_NOW, | |
158 | POWER_SUPPLY_PROP_PRESENT, | |
159 | }; | |
160 | ||
161 | /********************************************************************* | |
162 | * Initialisation | |
163 | *********************************************************************/ | |
164 | ||
c8afa640 | 165 | static int wm831x_backup_probe(struct platform_device *pdev) |
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166 | { |
167 | struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); | |
d0376031 | 168 | struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data; |
c26964ea | 169 | struct wm831x_backup *devdata; |
c26964ea | 170 | |
f11d018f JH |
171 | devdata = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_backup), |
172 | GFP_KERNEL); | |
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173 | if (devdata == NULL) |
174 | return -ENOMEM; | |
175 | ||
176 | devdata->wm831x = wm831x; | |
177 | platform_set_drvdata(pdev, devdata); | |
178 | ||
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179 | /* We ignore configuration failures since we can still read |
180 | * back the status without enabling the charger (which may | |
181 | * already be enabled anyway). | |
182 | */ | |
183 | wm831x_config_backup(wm831x); | |
184 | ||
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185 | if (wm831x_pdata && wm831x_pdata->wm831x_num) |
186 | snprintf(devdata->name, sizeof(devdata->name), | |
187 | "wm831x-backup.%d", wm831x_pdata->wm831x_num); | |
188 | else | |
189 | snprintf(devdata->name, sizeof(devdata->name), | |
190 | "wm831x-backup"); | |
191 | ||
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192 | devdata->backup_desc.name = devdata->name; |
193 | devdata->backup_desc.type = POWER_SUPPLY_TYPE_BATTERY; | |
194 | devdata->backup_desc.properties = wm831x_backup_props; | |
195 | devdata->backup_desc.num_properties = ARRAY_SIZE(wm831x_backup_props); | |
196 | devdata->backup_desc.get_property = wm831x_backup_get_prop; | |
197 | devdata->backup = power_supply_register(&pdev->dev, | |
198 | &devdata->backup_desc, NULL); | |
c26964ea | 199 | |
297d716f | 200 | return PTR_ERR_OR_ZERO(devdata->backup); |
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201 | } |
202 | ||
415ec69f | 203 | static int wm831x_backup_remove(struct platform_device *pdev) |
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204 | { |
205 | struct wm831x_backup *devdata = platform_get_drvdata(pdev); | |
206 | ||
297d716f | 207 | power_supply_unregister(devdata->backup); |
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208 | |
209 | return 0; | |
210 | } | |
211 | ||
212 | static struct platform_driver wm831x_backup_driver = { | |
213 | .probe = wm831x_backup_probe, | |
28ea73f4 | 214 | .remove = wm831x_backup_remove, |
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215 | .driver = { |
216 | .name = "wm831x-backup", | |
217 | }, | |
218 | }; | |
219 | ||
300bac7f | 220 | module_platform_driver(wm831x_backup_driver); |
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221 | |
222 | MODULE_DESCRIPTION("Backup battery charger driver for WM831x PMICs"); | |
223 | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); | |
224 | MODULE_LICENSE("GPL"); | |
225 | MODULE_ALIAS("platform:wm831x-backup"); |