cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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wm831x_backup.c (5463B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Backup battery driver for Wolfson Microelectronics wm831x PMICs
      4 *
      5 * Copyright 2009 Wolfson Microelectronics PLC.
      6 */
      7
      8#include <linux/module.h>
      9#include <linux/err.h>
     10#include <linux/platform_device.h>
     11#include <linux/power_supply.h>
     12#include <linux/slab.h>
     13
     14#include <linux/mfd/wm831x/core.h>
     15#include <linux/mfd/wm831x/auxadc.h>
     16#include <linux/mfd/wm831x/pmu.h>
     17#include <linux/mfd/wm831x/pdata.h>
     18
     19struct wm831x_backup {
     20	struct wm831x *wm831x;
     21	struct power_supply *backup;
     22	struct power_supply_desc backup_desc;
     23	char name[20];
     24};
     25
     26static 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
     43static 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
    112static 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
    152static 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
    162static int wm831x_backup_probe(struct platform_device *pdev)
    163{
    164	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
    165	struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data;
    166	struct wm831x_backup *devdata;
    167
    168	devdata = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_backup),
    169				GFP_KERNEL);
    170	if (devdata == NULL)
    171		return -ENOMEM;
    172
    173	devdata->wm831x = wm831x;
    174	platform_set_drvdata(pdev, devdata);
    175
    176	/* We ignore configuration failures since we can still read
    177	 * back the status without enabling the charger (which may
    178	 * already be enabled anyway).
    179	 */
    180	wm831x_config_backup(wm831x);
    181
    182	if (wm831x_pdata && wm831x_pdata->wm831x_num)
    183		snprintf(devdata->name, sizeof(devdata->name),
    184			 "wm831x-backup.%d", wm831x_pdata->wm831x_num);
    185	else
    186		snprintf(devdata->name, sizeof(devdata->name),
    187			 "wm831x-backup");
    188
    189	devdata->backup_desc.name = devdata->name;
    190	devdata->backup_desc.type = POWER_SUPPLY_TYPE_BATTERY;
    191	devdata->backup_desc.properties = wm831x_backup_props;
    192	devdata->backup_desc.num_properties = ARRAY_SIZE(wm831x_backup_props);
    193	devdata->backup_desc.get_property = wm831x_backup_get_prop;
    194	devdata->backup = power_supply_register(&pdev->dev,
    195						&devdata->backup_desc, NULL);
    196
    197	return PTR_ERR_OR_ZERO(devdata->backup);
    198}
    199
    200static 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
    206	return 0;
    207}
    208
    209static struct platform_driver wm831x_backup_driver = {
    210	.probe = wm831x_backup_probe,
    211	.remove = wm831x_backup_remove,
    212	.driver = {
    213		.name = "wm831x-backup",
    214	},
    215};
    216
    217module_platform_driver(wm831x_backup_driver);
    218
    219MODULE_DESCRIPTION("Backup battery charger driver for WM831x PMICs");
    220MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
    221MODULE_LICENSE("GPL");
    222MODULE_ALIAS("platform:wm831x-backup");