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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> | |
15 | ||
16 | #include <linux/mfd/wm831x/core.h> | |
17 | #include <linux/mfd/wm831x/auxadc.h> | |
18 | #include <linux/mfd/wm831x/pmu.h> | |
19 | #include <linux/mfd/wm831x/pdata.h> | |
20 | ||
21 | struct wm831x_backup { | |
22 | struct wm831x *wm831x; | |
23 | struct power_supply backup; | |
24 | }; | |
25 | ||
26 | static int wm831x_backup_read_voltage(struct wm831x *wm831x, | |
27 | enum wm831x_auxadc src, | |
28 | union power_supply_propval *val) | |
29 | { | |
30 | int ret; | |
31 | ||
32 | ret = wm831x_auxadc_read_uv(wm831x, src); | |
33 | if (ret >= 0) | |
34 | val->intval = ret; | |
35 | ||
36 | return ret; | |
37 | } | |
38 | ||
39 | /********************************************************************* | |
40 | * Backup supply properties | |
41 | *********************************************************************/ | |
42 | ||
43 | static void wm831x_config_backup(struct wm831x *wm831x) | |
44 | { | |
45 | struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data; | |
46 | struct wm831x_backup_pdata *pdata; | |
47 | int ret, reg; | |
48 | ||
49 | if (!wm831x_pdata || !wm831x_pdata->backup) { | |
50 | dev_warn(wm831x->dev, | |
51 | "No backup battery charger configuration\n"); | |
52 | return; | |
53 | } | |
54 | ||
55 | pdata = wm831x_pdata->backup; | |
56 | ||
57 | reg = 0; | |
58 | ||
59 | if (pdata->charger_enable) | |
60 | reg |= WM831X_BKUP_CHG_ENA | WM831X_BKUP_BATT_DET_ENA; | |
61 | if (pdata->no_constant_voltage) | |
62 | reg |= WM831X_BKUP_CHG_MODE; | |
63 | ||
64 | switch (pdata->vlim) { | |
65 | case 2500: | |
66 | break; | |
67 | case 3100: | |
68 | reg |= WM831X_BKUP_CHG_VLIM; | |
69 | break; | |
70 | default: | |
71 | dev_err(wm831x->dev, "Invalid backup voltage limit %dmV\n", | |
72 | pdata->vlim); | |
73 | } | |
74 | ||
75 | switch (pdata->ilim) { | |
76 | case 100: | |
77 | break; | |
78 | case 200: | |
79 | reg |= 1; | |
80 | break; | |
81 | case 300: | |
82 | reg |= 2; | |
83 | break; | |
84 | case 400: | |
85 | reg |= 3; | |
86 | break; | |
87 | default: | |
88 | dev_err(wm831x->dev, "Invalid backup current limit %duA\n", | |
89 | pdata->ilim); | |
90 | } | |
91 | ||
92 | ret = wm831x_reg_unlock(wm831x); | |
93 | if (ret != 0) { | |
94 | dev_err(wm831x->dev, "Failed to unlock registers: %d\n", ret); | |
95 | return; | |
96 | } | |
97 | ||
98 | ret = wm831x_set_bits(wm831x, WM831X_BACKUP_CHARGER_CONTROL, | |
99 | WM831X_BKUP_CHG_ENA_MASK | | |
100 | WM831X_BKUP_CHG_MODE_MASK | | |
101 | WM831X_BKUP_BATT_DET_ENA_MASK | | |
102 | WM831X_BKUP_CHG_VLIM_MASK | | |
103 | WM831X_BKUP_CHG_ILIM_MASK, | |
104 | reg); | |
105 | if (ret != 0) | |
106 | dev_err(wm831x->dev, | |
107 | "Failed to set backup charger config: %d\n", ret); | |
108 | ||
109 | wm831x_reg_lock(wm831x); | |
110 | } | |
111 | ||
112 | static int wm831x_backup_get_prop(struct power_supply *psy, | |
113 | enum power_supply_property psp, | |
114 | union power_supply_propval *val) | |
115 | { | |
116 | struct wm831x_backup *devdata = dev_get_drvdata(psy->dev->parent); | |
117 | struct wm831x *wm831x = devdata->wm831x; | |
118 | int ret = 0; | |
119 | ||
120 | ret = wm831x_reg_read(wm831x, WM831X_BACKUP_CHARGER_CONTROL); | |
121 | if (ret < 0) | |
122 | return ret; | |
123 | ||
124 | switch (psp) { | |
125 | case POWER_SUPPLY_PROP_STATUS: | |
126 | if (ret & WM831X_BKUP_CHG_STS) | |
127 | val->intval = POWER_SUPPLY_STATUS_CHARGING; | |
128 | else | |
129 | val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; | |
130 | break; | |
131 | ||
132 | case POWER_SUPPLY_PROP_VOLTAGE_NOW: | |
133 | ret = wm831x_backup_read_voltage(wm831x, WM831X_AUX_BKUP_BATT, | |
134 | val); | |
135 | break; | |
136 | ||
137 | case POWER_SUPPLY_PROP_PRESENT: | |
138 | if (ret & WM831X_BKUP_CHG_STS) | |
139 | val->intval = 1; | |
140 | else | |
141 | val->intval = 0; | |
142 | break; | |
143 | ||
144 | default: | |
145 | ret = -EINVAL; | |
146 | break; | |
147 | } | |
148 | ||
149 | return ret; | |
150 | } | |
151 | ||
152 | static enum power_supply_property wm831x_backup_props[] = { | |
153 | POWER_SUPPLY_PROP_STATUS, | |
154 | POWER_SUPPLY_PROP_VOLTAGE_NOW, | |
155 | POWER_SUPPLY_PROP_PRESENT, | |
156 | }; | |
157 | ||
158 | /********************************************************************* | |
159 | * Initialisation | |
160 | *********************************************************************/ | |
161 | ||
162 | static __devinit int wm831x_backup_probe(struct platform_device *pdev) | |
163 | { | |
164 | struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); | |
165 | struct wm831x_backup *devdata; | |
166 | struct power_supply *backup; | |
167 | int ret, irq, i; | |
168 | ||
169 | devdata = kzalloc(sizeof(struct wm831x_backup), GFP_KERNEL); | |
170 | if (devdata == NULL) | |
171 | return -ENOMEM; | |
172 | ||
173 | devdata->wm831x = wm831x; | |
174 | platform_set_drvdata(pdev, devdata); | |
175 | ||
176 | backup = &devdata->backup; | |
177 | ||
178 | /* We ignore configuration failures since we can still read | |
179 | * back the status without enabling the charger (which may | |
180 | * already be enabled anyway). | |
181 | */ | |
182 | wm831x_config_backup(wm831x); | |
183 | ||
184 | backup->name = "wm831x-backup"; | |
185 | backup->type = POWER_SUPPLY_TYPE_BATTERY; | |
186 | backup->properties = wm831x_backup_props; | |
187 | backup->num_properties = ARRAY_SIZE(wm831x_backup_props); | |
188 | backup->get_property = wm831x_backup_get_prop; | |
189 | ret = power_supply_register(&pdev->dev, backup); | |
190 | if (ret) | |
191 | goto err_kmalloc; | |
192 | ||
193 | return ret; | |
194 | ||
195 | err_kmalloc: | |
196 | kfree(devdata); | |
197 | return ret; | |
198 | } | |
199 | ||
200 | static __devexit int wm831x_backup_remove(struct platform_device *pdev) | |
201 | { | |
202 | struct wm831x_backup *devdata = platform_get_drvdata(pdev); | |
203 | ||
204 | power_supply_unregister(&devdata->backup); | |
205 | kfree(devdata); | |
206 | ||
207 | return 0; | |
208 | } | |
209 | ||
210 | static struct platform_driver wm831x_backup_driver = { | |
211 | .probe = wm831x_backup_probe, | |
212 | .remove = __devexit_p(wm831x_backup_remove), | |
213 | .driver = { | |
214 | .name = "wm831x-backup", | |
215 | }, | |
216 | }; | |
217 | ||
218 | static int __init wm831x_backup_init(void) | |
219 | { | |
220 | return platform_driver_register(&wm831x_backup_driver); | |
221 | } | |
222 | module_init(wm831x_backup_init); | |
223 | ||
224 | static void __exit wm831x_backup_exit(void) | |
225 | { | |
226 | platform_driver_unregister(&wm831x_backup_driver); | |
227 | } | |
228 | module_exit(wm831x_backup_exit); | |
229 | ||
230 | MODULE_DESCRIPTION("Backup battery charger driver for WM831x PMICs"); | |
231 | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); | |
232 | MODULE_LICENSE("GPL"); | |
233 | MODULE_ALIAS("platform:wm831x-backup"); |