linux/drivers/power/lp8788-charger.c

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/*
* TI LP8788 MFD - battery charger driver
*
* Copyright 2012 Texas Instruments
*
* Author: Milo(Woogyom) Kim <milo.kim@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/err.h>
#include <linux/iio/consumer.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/mfd/lp8788.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
/* register address */
#define LP8788_CHG_STATUS 0x07
#define LP8788_CHG_IDCIN 0x13
#define LP8788_CHG_IBATT 0x14
#define LP8788_CHG_VTERM 0x15
#define LP8788_CHG_EOC 0x16
/* mask/shift bits */
#define LP8788_CHG_INPUT_STATE_M 0x03 /* Addr 07h */
#define LP8788_CHG_STATE_M 0x3C
#define LP8788_CHG_STATE_S 2
#define LP8788_NO_BATT_M BIT(6)
#define LP8788_BAD_BATT_M BIT(7)
#define LP8788_CHG_IBATT_M 0x1F /* Addr 14h */
#define LP8788_CHG_VTERM_M 0x0F /* Addr 15h */
#define LP8788_CHG_EOC_LEVEL_M 0x30 /* Addr 16h */
#define LP8788_CHG_EOC_LEVEL_S 4
#define LP8788_CHG_EOC_TIME_M 0x0E
#define LP8788_CHG_EOC_TIME_S 1
#define LP8788_CHG_EOC_MODE_M BIT(0)
#define LP8788_CHARGER_NAME "charger"
#define LP8788_BATTERY_NAME "main_batt"
#define LP8788_CHG_START 0x11
#define LP8788_CHG_END 0x1C
#define LP8788_ISEL_MAX 23
#define LP8788_ISEL_STEP 50
#define LP8788_VTERM_MIN 4100
#define LP8788_VTERM_STEP 25
#define LP8788_MAX_BATT_CAPACITY 100
#define LP8788_MAX_CHG_IRQS 11
enum lp8788_charging_state {
LP8788_OFF,
LP8788_WARM_UP,
LP8788_LOW_INPUT = 0x3,
LP8788_PRECHARGE,
LP8788_CC,
LP8788_CV,
LP8788_MAINTENANCE,
LP8788_BATTERY_FAULT,
LP8788_SYSTEM_SUPPORT = 0xC,
LP8788_HIGH_CURRENT = 0xF,
LP8788_MAX_CHG_STATE,
};
enum lp8788_charger_adc_sel {
LP8788_VBATT,
LP8788_BATT_TEMP,
LP8788_NUM_CHG_ADC,
};
enum lp8788_charger_input_state {
LP8788_SYSTEM_SUPPLY = 1,
LP8788_FULL_FUNCTION,
};
/*
* struct lp8788_chg_irq
* @which : lp8788 interrupt id
* @virq : Linux IRQ number from irq_domain
*/
struct lp8788_chg_irq {
enum lp8788_int_id which;
int virq;
};
/*
* struct lp8788_charger
* @lp : used for accessing the registers of mfd lp8788 device
* @charger : power supply driver for the battery charger
* @battery : power supply driver for the battery
* @charger_work : work queue for charger input interrupts
* @chan : iio channels for getting adc values
* eg) battery voltage, capacity and temperature
* @irqs : charger dedicated interrupts
* @num_irqs : total numbers of charger interrupts
* @pdata : charger platform specific data
*/
struct lp8788_charger {
struct lp8788 *lp;
struct power_supply charger;
struct power_supply battery;
struct work_struct charger_work;
struct iio_channel *chan[LP8788_NUM_CHG_ADC];
struct lp8788_chg_irq irqs[LP8788_MAX_CHG_IRQS];
int num_irqs;
struct lp8788_charger_platform_data *pdata;
};
static char *battery_supplied_to[] = {
LP8788_BATTERY_NAME,
};
static enum power_supply_property lp8788_charger_prop[] = {
POWER_SUPPLY_PROP_ONLINE,
POWER_SUPPLY_PROP_CURRENT_MAX,
};
static enum power_supply_property lp8788_battery_prop[] = {
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_HEALTH,
POWER_SUPPLY_PROP_PRESENT,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_CAPACITY,
POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
POWER_SUPPLY_PROP_TEMP,
};
static bool lp8788_is_charger_detected(struct lp8788_charger *pchg)
{
u8 data;
lp8788_read_byte(pchg->lp, LP8788_CHG_STATUS, &data);
data &= LP8788_CHG_INPUT_STATE_M;
return data == LP8788_SYSTEM_SUPPLY || data == LP8788_FULL_FUNCTION;
}
static int lp8788_charger_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct lp8788_charger *pchg = dev_get_drvdata(psy->dev->parent);
u8 read;
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = lp8788_is_charger_detected(pchg);
break;
case POWER_SUPPLY_PROP_CURRENT_MAX:
lp8788_read_byte(pchg->lp, LP8788_CHG_IDCIN, &read);
val->intval = LP8788_ISEL_STEP *
(min_t(int, read, LP8788_ISEL_MAX) + 1);
break;
default:
return -EINVAL;
}
return 0;
}
static int lp8788_get_battery_status(struct lp8788_charger *pchg,
union power_supply_propval *val)
{
enum lp8788_charging_state state;
u8 data;
int ret;
ret = lp8788_read_byte(pchg->lp, LP8788_CHG_STATUS, &data);
if (ret)
return ret;
state = (data & LP8788_CHG_STATE_M) >> LP8788_CHG_STATE_S;
switch (state) {
case LP8788_OFF:
val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
break;
case LP8788_PRECHARGE:
case LP8788_CC:
case LP8788_CV:
case LP8788_HIGH_CURRENT:
val->intval = POWER_SUPPLY_STATUS_CHARGING;
break;
case LP8788_MAINTENANCE:
val->intval = POWER_SUPPLY_STATUS_FULL;
break;
default:
val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
break;
}
return 0;
}
static int lp8788_get_battery_health(struct lp8788_charger *pchg,
union power_supply_propval *val)
{
u8 data;
int ret;
ret = lp8788_read_byte(pchg->lp, LP8788_CHG_STATUS, &data);
if (ret)
return ret;
if (data & LP8788_NO_BATT_M)
val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
else if (data & LP8788_BAD_BATT_M)
val->intval = POWER_SUPPLY_HEALTH_DEAD;
else
val->intval = POWER_SUPPLY_HEALTH_GOOD;
return 0;
}
static int lp8788_get_battery_present(struct lp8788_charger *pchg,
union power_supply_propval *val)
{
u8 data;
int ret;
ret = lp8788_read_byte(pchg->lp, LP8788_CHG_STATUS, &data);
if (ret)
return ret;
val->intval = !(data & LP8788_NO_BATT_M);
return 0;
}
static int lp8788_get_vbatt_adc(struct lp8788_charger *pchg, int *result)
{
struct iio_channel *channel = pchg->chan[LP8788_VBATT];
if (!channel)
return -EINVAL;
return iio_read_channel_processed(channel, result);
}
static int lp8788_get_battery_voltage(struct lp8788_charger *pchg,
union power_supply_propval *val)
{
return lp8788_get_vbatt_adc(pchg, &val->intval);
}
static int lp8788_get_battery_capacity(struct lp8788_charger *pchg,
union power_supply_propval *val)
{
struct lp8788 *lp = pchg->lp;
struct lp8788_charger_platform_data *pdata = pchg->pdata;
unsigned int max_vbatt;
int vbatt;
enum lp8788_charging_state state;
u8 data;
int ret;
if (!pdata)
return -EINVAL;
max_vbatt = pdata->max_vbatt_mv;
if (max_vbatt == 0)
return -EINVAL;
ret = lp8788_read_byte(lp, LP8788_CHG_STATUS, &data);
if (ret)
return ret;
state = (data & LP8788_CHG_STATE_M) >> LP8788_CHG_STATE_S;
if (state == LP8788_MAINTENANCE) {
val->intval = LP8788_MAX_BATT_CAPACITY;
} else {
ret = lp8788_get_vbatt_adc(pchg, &vbatt);
if (ret)
return ret;
val->intval = (vbatt * LP8788_MAX_BATT_CAPACITY) / max_vbatt;
val->intval = min(val->intval, LP8788_MAX_BATT_CAPACITY);
}
return 0;
}
static int lp8788_get_battery_temperature(struct lp8788_charger *pchg,
union power_supply_propval *val)
{
struct iio_channel *channel = pchg->chan[LP8788_BATT_TEMP];
int result;
int ret;
if (!channel)
return -EINVAL;
ret = iio_read_channel_processed(channel, &result);
if (ret < 0)
return -EINVAL;
/* unit: 0.1 'C */
val->intval = result * 10;
return 0;
}
static int lp8788_get_battery_charging_current(struct lp8788_charger *pchg,
union power_supply_propval *val)
{
u8 read;
lp8788_read_byte(pchg->lp, LP8788_CHG_IBATT, &read);
read &= LP8788_CHG_IBATT_M;
val->intval = LP8788_ISEL_STEP *
(min_t(int, read, LP8788_ISEL_MAX) + 1);
return 0;
}
static int lp8788_get_charging_termination_voltage(struct lp8788_charger *pchg,
union power_supply_propval *val)
{
u8 read;
lp8788_read_byte(pchg->lp, LP8788_CHG_VTERM, &read);
read &= LP8788_CHG_VTERM_M;
val->intval = LP8788_VTERM_MIN + LP8788_VTERM_STEP * read;
return 0;
}
static int lp8788_battery_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct lp8788_charger *pchg = dev_get_drvdata(psy->dev->parent);
switch (psp) {
case POWER_SUPPLY_PROP_STATUS:
return lp8788_get_battery_status(pchg, val);
case POWER_SUPPLY_PROP_HEALTH:
return lp8788_get_battery_health(pchg, val);
case POWER_SUPPLY_PROP_PRESENT:
return lp8788_get_battery_present(pchg, val);
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
return lp8788_get_battery_voltage(pchg, val);
case POWER_SUPPLY_PROP_CAPACITY:
return lp8788_get_battery_capacity(pchg, val);
case POWER_SUPPLY_PROP_TEMP:
return lp8788_get_battery_temperature(pchg, val);
case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
return lp8788_get_battery_charging_current(pchg, val);
case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
return lp8788_get_charging_termination_voltage(pchg, val);
default:
return -EINVAL;
}
}
static inline bool lp8788_is_valid_charger_register(u8 addr)
{
return addr >= LP8788_CHG_START && addr <= LP8788_CHG_END;
}
static int lp8788_update_charger_params(struct platform_device *pdev,
struct lp8788_charger *pchg)
{
struct lp8788 *lp = pchg->lp;
struct lp8788_charger_platform_data *pdata = pchg->pdata;
struct lp8788_chg_param *param;
int i;
int ret;
if (!pdata || !pdata->chg_params) {
dev_info(&pdev->dev, "skip updating charger parameters\n");
return 0;
}
/* settting charging parameters */
for (i = 0; i < pdata->num_chg_params; i++) {
param = pdata->chg_params + i;
if (!param)
continue;
if (lp8788_is_valid_charger_register(param->addr)) {
ret = lp8788_write_byte(lp, param->addr, param->val);
if (ret)
return ret;
}
}
return 0;
}
static int lp8788_psy_register(struct platform_device *pdev,
struct lp8788_charger *pchg)
{
pchg->charger.name = LP8788_CHARGER_NAME;
pchg->charger.type = POWER_SUPPLY_TYPE_MAINS;
pchg->charger.properties = lp8788_charger_prop;
pchg->charger.num_properties = ARRAY_SIZE(lp8788_charger_prop);
pchg->charger.get_property = lp8788_charger_get_property;
pchg->charger.supplied_to = battery_supplied_to;
pchg->charger.num_supplicants = ARRAY_SIZE(battery_supplied_to);
if (power_supply_register(&pdev->dev, &pchg->charger))
return -EPERM;
pchg->battery.name = LP8788_BATTERY_NAME;
pchg->battery.type = POWER_SUPPLY_TYPE_BATTERY;
pchg->battery.properties = lp8788_battery_prop;
pchg->battery.num_properties = ARRAY_SIZE(lp8788_battery_prop);
pchg->battery.get_property = lp8788_battery_get_property;
if (power_supply_register(&pdev->dev, &pchg->battery))
return -EPERM;
return 0;
}
static void lp8788_psy_unregister(struct lp8788_charger *pchg)
{
power_supply_unregister(&pchg->battery);
power_supply_unregister(&pchg->charger);
}
static void lp8788_charger_event(struct work_struct *work)
{
struct lp8788_charger *pchg =
container_of(work, struct lp8788_charger, charger_work);
struct lp8788_charger_platform_data *pdata = pchg->pdata;
enum lp8788_charger_event event = lp8788_is_charger_detected(pchg);
pdata->charger_event(pchg->lp, event);
}
static bool lp8788_find_irq_id(struct lp8788_charger *pchg, int virq, int *id)
{
bool found;
int i;
for (i = 0; i < pchg->num_irqs; i++) {
if (pchg->irqs[i].virq == virq) {
*id = pchg->irqs[i].which;
found = true;
break;
}
}
return found;
}
static irqreturn_t lp8788_charger_irq_thread(int virq, void *ptr)
{
struct lp8788_charger *pchg = ptr;
struct lp8788_charger_platform_data *pdata = pchg->pdata;
int id = -1;
if (!lp8788_find_irq_id(pchg, virq, &id))
return IRQ_NONE;
switch (id) {
case LP8788_INT_CHG_INPUT_STATE:
case LP8788_INT_CHG_STATE:
case LP8788_INT_EOC:
case LP8788_INT_BATT_LOW:
case LP8788_INT_NO_BATT:
power_supply_changed(&pchg->charger);
power_supply_changed(&pchg->battery);
break;
default:
break;
}
/* report charger dectection event if used */
if (!pdata)
goto irq_handled;
if (pdata->charger_event && id == LP8788_INT_CHG_INPUT_STATE)
schedule_work(&pchg->charger_work);
irq_handled:
return IRQ_HANDLED;
}
static int lp8788_set_irqs(struct platform_device *pdev,
struct lp8788_charger *pchg, const char *name)
{
struct resource *r;
struct irq_domain *irqdm = pchg->lp->irqdm;
int irq_start;
int irq_end;
int virq;
int nr_irq;
int i;
int ret;
/* no error even if no irq resource */
r = platform_get_resource_byname(pdev, IORESOURCE_IRQ, name);
if (!r)
return 0;
irq_start = r->start;
irq_end = r->end;
for (i = irq_start; i <= irq_end; i++) {
nr_irq = pchg->num_irqs;
virq = irq_create_mapping(irqdm, i);
pchg->irqs[nr_irq].virq = virq;
pchg->irqs[nr_irq].which = i;
pchg->num_irqs++;
ret = request_threaded_irq(virq, NULL,
lp8788_charger_irq_thread,
0, name, pchg);
if (ret)
break;
}
if (i <= irq_end)
goto err_free_irq;
return 0;
err_free_irq:
for (i = 0; i < pchg->num_irqs; i++)
free_irq(pchg->irqs[i].virq, pchg);
return ret;
}
static int lp8788_irq_register(struct platform_device *pdev,
struct lp8788_charger *pchg)
{
const char *name[] = {
LP8788_CHG_IRQ, LP8788_PRSW_IRQ, LP8788_BATT_IRQ
};
int i;
int ret;
INIT_WORK(&pchg->charger_work, lp8788_charger_event);
pchg->num_irqs = 0;
for (i = 0; i < ARRAY_SIZE(name); i++) {
ret = lp8788_set_irqs(pdev, pchg, name[i]);
if (ret) {
dev_warn(&pdev->dev, "irq setup failed: %s\n", name[i]);
return ret;
}
}
if (pchg->num_irqs > LP8788_MAX_CHG_IRQS) {
dev_err(&pdev->dev, "invalid total number of irqs: %d\n",
pchg->num_irqs);
return -EINVAL;
}
return 0;
}
static void lp8788_irq_unregister(struct platform_device *pdev,
struct lp8788_charger *pchg)
{
int i;
int irq;
for (i = 0; i < pchg->num_irqs; i++) {
irq = pchg->irqs[i].virq;
if (!irq)
continue;
free_irq(irq, pchg);
}
}
static void lp8788_setup_adc_channel(struct device *dev,
struct lp8788_charger *pchg)
{
struct lp8788_charger_platform_data *pdata = pchg->pdata;
struct iio_channel *chan;
if (!pdata)
return;
/* ADC channel for battery voltage */
chan = iio_channel_get(dev, pdata->adc_vbatt);
pchg->chan[LP8788_VBATT] = IS_ERR(chan) ? NULL : chan;
/* ADC channel for battery temperature */
chan = iio_channel_get(dev, pdata->adc_batt_temp);
pchg->chan[LP8788_BATT_TEMP] = IS_ERR(chan) ? NULL : chan;
}
static void lp8788_release_adc_channel(struct lp8788_charger *pchg)
{
int i;
for (i = 0; i < LP8788_NUM_CHG_ADC; i++) {
if (!pchg->chan[i])
continue;
iio_channel_release(pchg->chan[i]);
pchg->chan[i] = NULL;
}
}
static ssize_t lp8788_show_charger_status(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct lp8788_charger *pchg = dev_get_drvdata(dev);
enum lp8788_charging_state state;
char *desc[LP8788_MAX_CHG_STATE] = {
[LP8788_OFF] = "CHARGER OFF",
[LP8788_WARM_UP] = "WARM UP",
[LP8788_LOW_INPUT] = "LOW INPUT STATE",
[LP8788_PRECHARGE] = "CHARGING - PRECHARGE",
[LP8788_CC] = "CHARGING - CC",
[LP8788_CV] = "CHARGING - CV",
[LP8788_MAINTENANCE] = "NO CHARGING - MAINTENANCE",
[LP8788_BATTERY_FAULT] = "BATTERY FAULT",
[LP8788_SYSTEM_SUPPORT] = "SYSTEM SUPPORT",
[LP8788_HIGH_CURRENT] = "HIGH CURRENT",
};
u8 data;
lp8788_read_byte(pchg->lp, LP8788_CHG_STATUS, &data);
state = (data & LP8788_CHG_STATE_M) >> LP8788_CHG_STATE_S;
return scnprintf(buf, PAGE_SIZE, "%s\n", desc[state]);
}
static ssize_t lp8788_show_eoc_time(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct lp8788_charger *pchg = dev_get_drvdata(dev);
char *stime[] = { "400ms", "5min", "10min", "15min",
"20min", "25min", "30min" "No timeout" };
u8 val;
lp8788_read_byte(pchg->lp, LP8788_CHG_EOC, &val);
val = (val & LP8788_CHG_EOC_TIME_M) >> LP8788_CHG_EOC_TIME_S;
return scnprintf(buf, PAGE_SIZE, "End Of Charge Time: %s\n",
stime[val]);
}
static ssize_t lp8788_show_eoc_level(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct lp8788_charger *pchg = dev_get_drvdata(dev);
char *abs_level[] = { "25mA", "49mA", "75mA", "98mA" };
char *relative_level[] = { "5%", "10%", "15%", "20%" };
char *level;
u8 val;
u8 mode;
lp8788_read_byte(pchg->lp, LP8788_CHG_EOC, &val);
mode = val & LP8788_CHG_EOC_MODE_M;
val = (val & LP8788_CHG_EOC_LEVEL_M) >> LP8788_CHG_EOC_LEVEL_S;
level = mode ? abs_level[val] : relative_level[val];
return scnprintf(buf, PAGE_SIZE, "End Of Charge Level: %s\n", level);
}
static DEVICE_ATTR(charger_status, S_IRUSR, lp8788_show_charger_status, NULL);
static DEVICE_ATTR(eoc_time, S_IRUSR, lp8788_show_eoc_time, NULL);
static DEVICE_ATTR(eoc_level, S_IRUSR, lp8788_show_eoc_level, NULL);
static struct attribute *lp8788_charger_attr[] = {
&dev_attr_charger_status.attr,
&dev_attr_eoc_time.attr,
&dev_attr_eoc_level.attr,
NULL,
};
static const struct attribute_group lp8788_attr_group = {
.attrs = lp8788_charger_attr,
};
static int lp8788_charger_probe(struct platform_device *pdev)
{
struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
struct lp8788_charger *pchg;
struct device *dev = &pdev->dev;
int ret;
pchg = devm_kzalloc(dev, sizeof(struct lp8788_charger), GFP_KERNEL);
if (!pchg)
return -ENOMEM;
pchg->lp = lp;
pchg->pdata = lp->pdata ? lp->pdata->chg_pdata : NULL;
platform_set_drvdata(pdev, pchg);
ret = lp8788_update_charger_params(pdev, pchg);
if (ret)
return ret;
lp8788_setup_adc_channel(&pdev->dev, pchg);
ret = lp8788_psy_register(pdev, pchg);
if (ret)
return ret;
ret = sysfs_create_group(&pdev->dev.kobj, &lp8788_attr_group);
if (ret) {
lp8788_psy_unregister(pchg);
return ret;
}
ret = lp8788_irq_register(pdev, pchg);
if (ret)
dev_warn(dev, "failed to register charger irq: %d\n", ret);
return 0;
}
static int lp8788_charger_remove(struct platform_device *pdev)
{
struct lp8788_charger *pchg = platform_get_drvdata(pdev);
flush_work(&pchg->charger_work);
lp8788_irq_unregister(pdev, pchg);
sysfs_remove_group(&pdev->dev.kobj, &lp8788_attr_group);
lp8788_psy_unregister(pchg);
lp8788_release_adc_channel(pchg);
return 0;
}
static struct platform_driver lp8788_charger_driver = {
.probe = lp8788_charger_probe,
.remove = lp8788_charger_remove,
.driver = {
.name = LP8788_DEV_CHARGER,
.owner = THIS_MODULE,
},
};
module_platform_driver(lp8788_charger_driver);
MODULE_DESCRIPTION("TI LP8788 Charger Driver");
MODULE_AUTHOR("Milo Kim");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:lp8788-charger");