| 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"); |