1c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown/*
2c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown * Backup battery driver for Wolfson Microelectronics wm831x PMICs
3c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown *
4c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown * Copyright 2009 Wolfson Microelectronics PLC.
5c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown *
6c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown * This program is free software; you can redistribute it and/or modify
7c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown * it under the terms of the GNU General Public License version 2 as
8c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown * published by the Free Software Foundation.
9c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown */
10c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
11c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown#include <linux/module.h>
12c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown#include <linux/err.h>
13c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown#include <linux/platform_device.h>
14c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown#include <linux/power_supply.h>
155a0e3ad6af8660be21ca98a971cd00f331318c05Tejun Heo#include <linux/slab.h>
16c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
17c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown#include <linux/mfd/wm831x/core.h>
18c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown#include <linux/mfd/wm831x/auxadc.h>
19c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown#include <linux/mfd/wm831x/pmu.h>
20c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown#include <linux/mfd/wm831x/pdata.h>
21c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
22c26964ead57f0aa1dff4926aae2982b174798e7bMark Brownstruct wm831x_backup {
23c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	struct wm831x *wm831x;
24c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	struct power_supply backup;
25d03760318edbc78b72cb7fa96bddb65263384d24Mark Brown	char name[20];
26c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown};
27c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
28c26964ead57f0aa1dff4926aae2982b174798e7bMark Brownstatic int wm831x_backup_read_voltage(struct wm831x *wm831x,
29c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown				     enum wm831x_auxadc src,
30c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown				     union power_supply_propval *val)
31c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown{
32c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	int ret;
33c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
34c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	ret = wm831x_auxadc_read_uv(wm831x, src);
35c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	if (ret >= 0)
36c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		val->intval = ret;
37c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
38c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	return ret;
39c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown}
40c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
41c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown/*********************************************************************
42c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown *		Backup supply properties
43c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown *********************************************************************/
44c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
45c26964ead57f0aa1dff4926aae2982b174798e7bMark Brownstatic void wm831x_config_backup(struct wm831x *wm831x)
46c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown{
47c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data;
48c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	struct wm831x_backup_pdata *pdata;
49c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	int ret, reg;
50c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
51c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	if (!wm831x_pdata || !wm831x_pdata->backup) {
52c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		dev_warn(wm831x->dev,
53c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			 "No backup battery charger configuration\n");
54c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		return;
55c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	}
56c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
57c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	pdata = wm831x_pdata->backup;
58c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
59c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	reg = 0;
60c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
61c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	if (pdata->charger_enable)
62c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		reg |= WM831X_BKUP_CHG_ENA | WM831X_BKUP_BATT_DET_ENA;
63c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	if (pdata->no_constant_voltage)
64c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		reg |= WM831X_BKUP_CHG_MODE;
65c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
66c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	switch (pdata->vlim) {
67c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	case 2500:
68c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		break;
69c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	case 3100:
70c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		reg |= WM831X_BKUP_CHG_VLIM;
71c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		break;
72c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	default:
73c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		dev_err(wm831x->dev, "Invalid backup voltage limit %dmV\n",
74c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			pdata->vlim);
75c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	}
76c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
77c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	switch (pdata->ilim) {
78c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	case 100:
79c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		break;
80c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	case 200:
81c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		reg |= 1;
82c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		break;
83c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	case 300:
84c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		reg |= 2;
85c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		break;
86c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	case 400:
87c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		reg |= 3;
88c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		break;
89c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	default:
90c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		dev_err(wm831x->dev, "Invalid backup current limit %duA\n",
91c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			pdata->ilim);
92c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	}
93c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
94c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	ret = wm831x_reg_unlock(wm831x);
95c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	if (ret != 0) {
96c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		dev_err(wm831x->dev, "Failed to unlock registers: %d\n", ret);
97c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		return;
98c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	}
99c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
100c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	ret = wm831x_set_bits(wm831x, WM831X_BACKUP_CHARGER_CONTROL,
101c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			      WM831X_BKUP_CHG_ENA_MASK |
102c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			      WM831X_BKUP_CHG_MODE_MASK |
103c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			      WM831X_BKUP_BATT_DET_ENA_MASK |
104c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			      WM831X_BKUP_CHG_VLIM_MASK |
105c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			      WM831X_BKUP_CHG_ILIM_MASK,
106c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			      reg);
107c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	if (ret != 0)
108c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		dev_err(wm831x->dev,
109c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			"Failed to set backup charger config: %d\n", ret);
110c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
111c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	wm831x_reg_lock(wm831x);
112c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown}
113c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
114c26964ead57f0aa1dff4926aae2982b174798e7bMark Brownstatic int wm831x_backup_get_prop(struct power_supply *psy,
115c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown				  enum power_supply_property psp,
116c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown				  union power_supply_propval *val)
117c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown{
118c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	struct wm831x_backup *devdata = dev_get_drvdata(psy->dev->parent);
119c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	struct wm831x *wm831x = devdata->wm831x;
120c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	int ret = 0;
121c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
122c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	ret = wm831x_reg_read(wm831x, WM831X_BACKUP_CHARGER_CONTROL);
123c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	if (ret < 0)
124c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		return ret;
125c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
126c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	switch (psp) {
127c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	case POWER_SUPPLY_PROP_STATUS:
128c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		if (ret & WM831X_BKUP_CHG_STS)
129c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			val->intval = POWER_SUPPLY_STATUS_CHARGING;
130c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		else
131c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
132c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		break;
133c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
134c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
135c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		ret = wm831x_backup_read_voltage(wm831x, WM831X_AUX_BKUP_BATT,
136c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown						val);
137c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		break;
138c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
139c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	case POWER_SUPPLY_PROP_PRESENT:
140c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		if (ret & WM831X_BKUP_CHG_STS)
141c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			val->intval = 1;
142c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		else
143c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown			val->intval = 0;
144c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		break;
145c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
146c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	default:
147c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		ret = -EINVAL;
148c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		break;
149c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	}
150c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
151c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	return ret;
152c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown}
153c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
154c26964ead57f0aa1dff4926aae2982b174798e7bMark Brownstatic enum power_supply_property wm831x_backup_props[] = {
155c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	POWER_SUPPLY_PROP_STATUS,
156c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	POWER_SUPPLY_PROP_VOLTAGE_NOW,
157c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	POWER_SUPPLY_PROP_PRESENT,
158c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown};
159c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
160c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown/*********************************************************************
161c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown *		Initialisation
162c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown *********************************************************************/
163c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
164c26964ead57f0aa1dff4926aae2982b174798e7bMark Brownstatic __devinit int wm831x_backup_probe(struct platform_device *pdev)
165c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown{
166c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
167d03760318edbc78b72cb7fa96bddb65263384d24Mark Brown	struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data;
168c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	struct wm831x_backup *devdata;
169c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	struct power_supply *backup;
1700e19dbb73eab1f5de328e297b8b6d9887c3e73c2Alan Cox	int ret;
171c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
172c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	devdata = kzalloc(sizeof(struct wm831x_backup), GFP_KERNEL);
173c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	if (devdata == NULL)
174c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		return -ENOMEM;
175c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
176c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	devdata->wm831x = wm831x;
177c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	platform_set_drvdata(pdev, devdata);
178c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
179c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	backup = &devdata->backup;
180c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
181c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	/* We ignore configuration failures since we can still read
182c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	 * back the status without enabling the charger (which may
183c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	 * already be enabled anyway).
184c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	 */
185c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	wm831x_config_backup(wm831x);
186c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
187d03760318edbc78b72cb7fa96bddb65263384d24Mark Brown	if (wm831x_pdata && wm831x_pdata->wm831x_num)
188d03760318edbc78b72cb7fa96bddb65263384d24Mark Brown		snprintf(devdata->name, sizeof(devdata->name),
189d03760318edbc78b72cb7fa96bddb65263384d24Mark Brown			 "wm831x-backup.%d", wm831x_pdata->wm831x_num);
190d03760318edbc78b72cb7fa96bddb65263384d24Mark Brown	else
191d03760318edbc78b72cb7fa96bddb65263384d24Mark Brown		snprintf(devdata->name, sizeof(devdata->name),
192d03760318edbc78b72cb7fa96bddb65263384d24Mark Brown			 "wm831x-backup");
193d03760318edbc78b72cb7fa96bddb65263384d24Mark Brown
194d03760318edbc78b72cb7fa96bddb65263384d24Mark Brown	backup->name = devdata->name;
195c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	backup->type = POWER_SUPPLY_TYPE_BATTERY;
196c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	backup->properties = wm831x_backup_props;
197c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	backup->num_properties = ARRAY_SIZE(wm831x_backup_props);
198c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	backup->get_property = wm831x_backup_get_prop;
199c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	ret = power_supply_register(&pdev->dev, backup);
200c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	if (ret)
201c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		goto err_kmalloc;
202c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
203c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	return ret;
204c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
205c26964ead57f0aa1dff4926aae2982b174798e7bMark Brownerr_kmalloc:
206c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	kfree(devdata);
207c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	return ret;
208c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown}
209c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
210c26964ead57f0aa1dff4926aae2982b174798e7bMark Brownstatic __devexit int wm831x_backup_remove(struct platform_device *pdev)
211c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown{
212c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	struct wm831x_backup *devdata = platform_get_drvdata(pdev);
213c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
214c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	power_supply_unregister(&devdata->backup);
215d03760318edbc78b72cb7fa96bddb65263384d24Mark Brown	kfree(devdata->backup.name);
216c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	kfree(devdata);
217c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
218c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	return 0;
219c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown}
220c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
221c26964ead57f0aa1dff4926aae2982b174798e7bMark Brownstatic struct platform_driver wm831x_backup_driver = {
222c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	.probe = wm831x_backup_probe,
223c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	.remove = __devexit_p(wm831x_backup_remove),
224c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	.driver = {
225c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown		.name = "wm831x-backup",
226c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown	},
227c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown};
228c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
229300bac7fb85a20b2704dc3645419057992f78565Axel Linmodule_platform_driver(wm831x_backup_driver);
230c26964ead57f0aa1dff4926aae2982b174798e7bMark Brown
231c26964ead57f0aa1dff4926aae2982b174798e7bMark BrownMODULE_DESCRIPTION("Backup battery charger driver for WM831x PMICs");
232c26964ead57f0aa1dff4926aae2982b174798e7bMark BrownMODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
233c26964ead57f0aa1dff4926aae2982b174798e7bMark BrownMODULE_LICENSE("GPL");
234c26964ead57f0aa1dff4926aae2982b174798e7bMark BrownMODULE_ALIAS("platform:wm831x-backup");
235