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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> |
c26964ea MB |
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; | |
25 | }; | |
26 | ||
27 | static int wm831x_backup_read_voltage(struct wm831x *wm831x, | |
28 | enum wm831x_auxadc src, | |
29 | union power_supply_propval *val) | |
30 | { | |
31 | int ret; | |
32 | ||
33 | ret = wm831x_auxadc_read_uv(wm831x, src); | |
34 | if (ret >= 0) | |
35 | val->intval = ret; | |
36 | ||
37 | return ret; | |
38 | } | |
39 | ||
40 | /********************************************************************* | |
41 | * Backup supply properties | |
42 | *********************************************************************/ | |
43 | ||
44 | static void wm831x_config_backup(struct wm831x *wm831x) | |
45 | { | |
46 | struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data; | |
47 | struct wm831x_backup_pdata *pdata; | |
48 | int ret, reg; | |
49 | ||
50 | if (!wm831x_pdata || !wm831x_pdata->backup) { | |
51 | dev_warn(wm831x->dev, | |
52 | "No backup battery charger configuration\n"); | |
53 | return; | |
54 | } | |
55 | ||
56 | pdata = wm831x_pdata->backup; | |
57 | ||
58 | reg = 0; | |
59 | ||
60 | if (pdata->charger_enable) | |
61 | reg |= WM831X_BKUP_CHG_ENA | WM831X_BKUP_BATT_DET_ENA; | |
62 | if (pdata->no_constant_voltage) | |
63 | reg |= WM831X_BKUP_CHG_MODE; | |
64 | ||
65 | switch (pdata->vlim) { | |
66 | case 2500: | |
67 | break; | |
68 | case 3100: | |
69 | reg |= WM831X_BKUP_CHG_VLIM; | |
70 | break; | |
71 | default: | |
72 | dev_err(wm831x->dev, "Invalid backup voltage limit %dmV\n", | |
73 | pdata->vlim); | |
74 | } | |
75 | ||
76 | switch (pdata->ilim) { | |
77 | case 100: | |
78 | break; | |
79 | case 200: | |
80 | reg |= 1; | |
81 | break; | |
82 | case 300: | |
83 | reg |= 2; | |
84 | break; | |
85 | case 400: | |
86 | reg |= 3; | |
87 | break; | |
88 | default: | |
89 | dev_err(wm831x->dev, "Invalid backup current limit %duA\n", | |
90 | pdata->ilim); | |
91 | } | |
92 | ||
93 | ret = wm831x_reg_unlock(wm831x); | |
94 | if (ret != 0) { | |
95 | dev_err(wm831x->dev, "Failed to unlock registers: %d\n", ret); | |
96 | return; | |
97 | } | |
98 | ||
99 | ret = wm831x_set_bits(wm831x, WM831X_BACKUP_CHARGER_CONTROL, | |
100 | WM831X_BKUP_CHG_ENA_MASK | | |
101 | WM831X_BKUP_CHG_MODE_MASK | | |
102 | WM831X_BKUP_BATT_DET_ENA_MASK | | |
103 | WM831X_BKUP_CHG_VLIM_MASK | | |
104 | WM831X_BKUP_CHG_ILIM_MASK, | |
105 | reg); | |
106 | if (ret != 0) | |
107 | dev_err(wm831x->dev, | |
108 | "Failed to set backup charger config: %d\n", ret); | |
109 | ||
110 | wm831x_reg_lock(wm831x); | |
111 | } | |
112 | ||
113 | static int wm831x_backup_get_prop(struct power_supply *psy, | |
114 | enum power_supply_property psp, | |
115 | union power_supply_propval *val) | |
116 | { | |
117 | struct wm831x_backup *devdata = dev_get_drvdata(psy->dev->parent); | |
118 | struct wm831x *wm831x = devdata->wm831x; | |
119 | int ret = 0; | |
120 | ||
121 | ret = wm831x_reg_read(wm831x, WM831X_BACKUP_CHARGER_CONTROL); | |
122 | if (ret < 0) | |
123 | return ret; | |
124 | ||
125 | switch (psp) { | |
126 | case POWER_SUPPLY_PROP_STATUS: | |
127 | if (ret & WM831X_BKUP_CHG_STS) | |
128 | val->intval = POWER_SUPPLY_STATUS_CHARGING; | |
129 | else | |
130 | val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; | |
131 | break; | |
132 | ||
133 | case POWER_SUPPLY_PROP_VOLTAGE_NOW: | |
134 | ret = wm831x_backup_read_voltage(wm831x, WM831X_AUX_BKUP_BATT, | |
135 | val); | |
136 | break; | |
137 | ||
138 | case POWER_SUPPLY_PROP_PRESENT: | |
139 | if (ret & WM831X_BKUP_CHG_STS) | |
140 | val->intval = 1; | |
141 | else | |
142 | val->intval = 0; | |
143 | break; | |
144 | ||
145 | default: | |
146 | ret = -EINVAL; | |
147 | break; | |
148 | } | |
149 | ||
150 | return ret; | |
151 | } | |
152 | ||
153 | static enum power_supply_property wm831x_backup_props[] = { | |
154 | POWER_SUPPLY_PROP_STATUS, | |
155 | POWER_SUPPLY_PROP_VOLTAGE_NOW, | |
156 | POWER_SUPPLY_PROP_PRESENT, | |
157 | }; | |
158 | ||
159 | /********************************************************************* | |
160 | * Initialisation | |
161 | *********************************************************************/ | |
162 | ||
163 | static __devinit int wm831x_backup_probe(struct platform_device *pdev) | |
164 | { | |
165 | struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); | |
166 | struct wm831x_backup *devdata; | |
167 | struct power_supply *backup; | |
0e19dbb7 | 168 | int ret; |
c26964ea MB |
169 | |
170 | devdata = kzalloc(sizeof(struct wm831x_backup), GFP_KERNEL); | |
171 | if (devdata == NULL) | |
172 | return -ENOMEM; | |
173 | ||
174 | devdata->wm831x = wm831x; | |
175 | platform_set_drvdata(pdev, devdata); | |
176 | ||
177 | backup = &devdata->backup; | |
178 | ||
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 | ||
185 | backup->name = "wm831x-backup"; | |
186 | backup->type = POWER_SUPPLY_TYPE_BATTERY; | |
187 | backup->properties = wm831x_backup_props; | |
188 | backup->num_properties = ARRAY_SIZE(wm831x_backup_props); | |
189 | backup->get_property = wm831x_backup_get_prop; | |
190 | ret = power_supply_register(&pdev->dev, backup); | |
191 | if (ret) | |
192 | goto err_kmalloc; | |
193 | ||
194 | return ret; | |
195 | ||
196 | err_kmalloc: | |
197 | kfree(devdata); | |
198 | return ret; | |
199 | } | |
200 | ||
201 | static __devexit int wm831x_backup_remove(struct platform_device *pdev) | |
202 | { | |
203 | struct wm831x_backup *devdata = platform_get_drvdata(pdev); | |
204 | ||
205 | power_supply_unregister(&devdata->backup); | |
206 | kfree(devdata); | |
207 | ||
208 | return 0; | |
209 | } | |
210 | ||
211 | static struct platform_driver wm831x_backup_driver = { | |
212 | .probe = wm831x_backup_probe, | |
213 | .remove = __devexit_p(wm831x_backup_remove), | |
214 | .driver = { | |
215 | .name = "wm831x-backup", | |
216 | }, | |
217 | }; | |
218 | ||
219 | static int __init wm831x_backup_init(void) | |
220 | { | |
221 | return platform_driver_register(&wm831x_backup_driver); | |
222 | } | |
223 | module_init(wm831x_backup_init); | |
224 | ||
225 | static void __exit wm831x_backup_exit(void) | |
226 | { | |
227 | platform_driver_unregister(&wm831x_backup_driver); | |
228 | } | |
229 | module_exit(wm831x_backup_exit); | |
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"); |