/*
* TWL4030/TPS65950 BCI (Battery Charger Interface) driver
*
* Copyright (C) 2010 Gražvydas Ignotas <notasas@gmail.com>
*
* based on twl4030_bci_battery.c by TI
* Copyright (C) 2008 Texas Instruments, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/i2c/twl.h>
#include <linux/power_supply.h>
#include <linux/notifier.h>
#include <linux/usb/otg.h>
#define TWL4030_BCIMSTATEC 0x02
#define TWL4030_BCIICHG 0x08
#define TWL4030_BCIVAC 0x0a
#define TWL4030_BCIVBUS 0x0c
#define TWL4030_BCIMFSTS4 0x10
#define TWL4030_BCICTL1 0x23
#define TWL4030_BCIAUTOWEN BIT(5)
#define TWL4030_CONFIG_DONE BIT(4)
#define TWL4030_BCIAUTOUSB BIT(1)
#define TWL4030_BCIAUTOAC BIT(0)
#define TWL4030_CGAIN BIT(5)
#define TWL4030_USBFASTMCHG BIT(2)
#define TWL4030_STS_VBUS BIT(7)
#define TWL4030_STS_USB_ID BIT(2)
/* BCI interrupts */
#define TWL4030_WOVF BIT(0) /* Watchdog overflow */
#define TWL4030_TMOVF BIT(1) /* Timer overflow */
#define TWL4030_ICHGHIGH BIT(2) /* Battery charge current high */
#define TWL4030_ICHGLOW BIT(3) /* Battery cc. low / FSM state change */
#define TWL4030_ICHGEOC BIT(4) /* Battery current end-of-charge */
#define TWL4030_TBATOR2 BIT(5) /* Battery temperature out of range 2 */
#define TWL4030_TBATOR1 BIT(6) /* Battery temperature out of range 1 */
#define TWL4030_BATSTS BIT(7) /* Battery status */
#define TWL4030_VBATLVL BIT(0) /* VBAT level */
#define TWL4030_VBATOV BIT(1) /* VBAT overvoltage */
#define TWL4030_VBUSOV BIT(2) /* VBUS overvoltage */
#define TWL4030_ACCHGOV BIT(3) /* Ac charger overvoltage */
#define TWL4030_MSTATEC_USB BIT(4)
#define TWL4030_MSTATEC_AC BIT(5)
#define TWL4030_MSTATEC_MASK 0x0f
#define TWL4030_MSTATEC_QUICK1 0x02
#define TWL4030_MSTATEC_QUICK7 0x07
#define TWL4030_MSTATEC_COMPLETE1 0x0b
#define TWL4030_MSTATEC_COMPLETE4 0x0e
static bool allow_usb;
module_param(allow_usb, bool, 1);
MODULE_PARM_DESC(allow_usb, "Allow USB charge drawing default current");
struct twl4030_bci {
struct device *dev;
struct power_supply ac;
struct power_supply usb;
struct otg_transceiver *transceiver;
struct notifier_block otg_nb;
struct work_struct work;
int irq_chg;
int irq_bci;
unsigned long event;
};
/*
* clear and set bits on an given register on a given module
*/
static int twl4030_clear_set(u8 mod_no, u8 clear, u8 set, u8 reg)
{
u8 val = 0;
int ret;
ret = twl_i2c_read_u8(mod_no, &val, reg);
if (ret)
return ret;
val &= ~clear;
val |= set;
return twl_i2c_write_u8(mod_no, val, reg);
}
static int twl4030_bci_read(u8 reg, u8 *val)
{
return twl_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, val, reg);
}
static int twl4030_clear_set_boot_bci(u8 clear, u8 set)
{
return twl4030_clear_set(TWL4030_MODULE_PM_MASTER, 0,
TWL4030_CONFIG_DONE | TWL4030_BCIAUTOWEN | set,
TWL4030_PM_MASTER_BOOT_BCI);
}
static int twl4030bci_read_adc_val(u8 reg)
{
int ret, temp;
u8 val;
/* read MSB */
ret = twl4030_bci_read(reg + 1, &val);
if (ret)
return ret;
temp = (int)(val & 0x03) << 8;
/* read LSB */
ret = twl4030_bci_read(reg, &val);
if (ret)
return ret;
return temp | val;
}
/*
* Check if VBUS power is present
*/
static int twl4030_bci_have_vbus(struct twl4030_bci *bci)
{
int ret;
u8 hwsts;
ret = twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &hwsts,
TWL4030_PM_MASTER_STS_HW_CONDITIONS);
if (ret < 0)
return 0;
dev_dbg(bci->dev, "check_vbus: HW_CONDITIONS %02x\n", hwsts);
/* in case we also have STS_USB_ID, VBUS is driven by TWL itself */
if ((hwsts & TWL4030_STS_VBUS) && !(hwsts & TWL4030_STS_USB_ID))
return 1;
return 0;
}
/*
* Enable/Disable USB Charge funtionality.
*/
static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable)
{
int ret;
if (enable) {
/* Check for USB charger conneted */
if (!twl4030_bci_have_vbus(bci))
return -ENODEV;
/*
* Until we can find out what current the device can provide,
* require a module param to enable USB charging.
*/
if (!allow_usb) {
dev_warn(bci->dev, "USB charging is disabled.\n");
return -EACCES;
}
/* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */
ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOUSB);
if (ret < 0)
return ret;
/* forcing USBFASTMCHG(BCIMFSTS4[2]) to 1 */
ret = twl4030_clear_set(TWL4030_MODULE_MAIN_CHARGE, 0,
TWL4030_USBFASTMCHG, TWL4030_BCIMFSTS4);
} else {
ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOUSB, 0);
}
return ret;
}
/*
* Enable/Disable AC Charge funtionality.
*/
static int twl4030_charger_enable_ac(bool enable)
{
int ret;
if (enable)
ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOAC);
else
ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOAC, 0);
return ret;
}
/*
* TWL4030 CHG_PRES (AC charger presence) events
*/
static irqreturn_t twl4030_charger_interrupt(int irq, void *arg)
{
struct twl4030_bci *bci = arg;
dev_dbg(bci->dev, "CHG_PRES irq\n");
power_supply_changed(&bci->ac);
power_supply_changed(&bci->usb);
return IRQ_HANDLED;
}
/*
* TWL4030 BCI monitoring events
*/
static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
{
struct twl4030_bci *bci = arg;
u8 irqs1, irqs2;
int ret;
ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs1,
TWL4030_INTERRUPTS_BCIISR1A);
if (ret < 0)
return IRQ_HANDLED;
ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs2,
TWL4030_INTERRUPTS_BCIISR2A);
if (ret < 0)
return IRQ_HANDLED;
dev_dbg(bci->dev, "BCI irq %02x %02x\n", irqs2, irqs1);
if (irqs1 & (TWL4030_ICHGLOW | TWL4030_ICHGEOC)) {
/* charger state change, inform the core */
power_supply_changed(&bci->ac);
power_supply_changed(&bci->usb);
}
/* various monitoring events, for now we just log them here */
if (irqs1 & (TWL4030_TBATOR2 | TWL4030_TBATOR1))
dev_warn(bci->dev, "battery temperature out of range\n");
if (irqs1 & TWL4030_BATSTS)
dev_crit(bci->dev, "battery disconnected\n");
if (irqs2 & TWL4030_VBATOV)
dev_crit(bci->dev, "VBAT overvoltage\n");
if (irqs2 & TWL4030_VBUSOV)
dev_crit(bci->dev, "VBUS overvoltage\n");
if (irqs2 & TWL4030_ACCHGOV)
dev_crit(bci->dev, "Ac charger overvoltage\n");
return IRQ_HANDLED;
}
static void twl4030_bci_usb_work(struct work_struct *data)
{
struct twl4030_bci *bci = container_of(data, struct twl4030_bci, work);
switch (bci->event) {
case USB_EVENT_VBUS:
case USB_EVENT_CHARGER:
twl4030_charger_enable_usb(bci, true);
break;
case USB_EVENT_NONE:
twl4030_charger_enable_usb(bci, false);
break;
}
}
static int twl4030_bci_usb_ncb(struct notifier_block *nb, unsigned long val,
void *priv)
{
struct twl4030_bci *bci = container_of(nb, struct twl4030_bci, otg_nb);
dev_dbg(bci->dev, "OTG notify %lu\n", val);
bci->event = val;
schedule_work(&bci->work);
return NOTIFY_OK;
}
/*
* TI provided formulas:
* CGAIN == 0: ICHG = (BCIICHG * 1.7) / (2^10 - 1) - 0.85
* CGAIN == 1: ICHG = (BCIICHG * 3.4) / (2^10 - 1) - 1.7
* Here we use integer approximation of:
* CGAIN == 0: val * 1.6618 - 0.85
* CGAIN == 1: (val * 1.6618 - 0.85) * 2
*/
static int twl4030_charger_get_current(void)
{
int curr;
int ret;
u8 bcictl1;
curr = twl4030bci_read_adc_val(TWL4030_BCIICHG);
if (curr < 0)
return curr;
ret = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
if (ret)
return ret;
ret = (curr * 16618 - 850 * 10000) / 10;
if (bcictl1 & TWL4030_CGAIN)
ret *= 2;
return ret;
}
/*
* Returns the main charge FSM state
* Or < 0 on failure.
*/
static int twl4030bci_state(struct twl4030_bci *bci)
{
int ret;
u8 state;
ret = twl4030_bci_read(TWL4030_BCIMSTATEC, &state);
if (ret) {
pr_err("twl4030_bci: error reading BCIMSTATEC\n");
return ret;
}
dev_dbg(bci->dev, "state: %02x\n", state);
return state;
}
static int twl4030_bci_state_to_status(int state)
{
state &= TWL4030_MSTATEC_MASK;
if (TWL4030_MSTATEC_QUICK1 <= state && state <= TWL4030_MSTATEC_QUICK7)
return POWER_SUPPLY_STATUS_CHARGING;
else if (TWL4030_MSTATEC_COMPLETE1 <= state &&
state <= TWL4030_MSTATEC_COMPLETE4)
return POWER_SUPPLY_STATUS_FULL;
else
return POWER_SUPPLY_STATUS_NOT_CHARGING;
}
static int twl4030_bci_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct twl4030_bci *bci = dev_get_drvdata(psy->dev->parent);
int is_charging;
int state;
int ret;
state = twl4030bci_state(bci);
if (state < 0)
return state;
if (psy->type == POWER_SUPPLY_TYPE_USB)
is_charging = state & TWL4030_MSTATEC_USB;
else
is_charging = state & TWL4030_MSTATEC_AC;
switch (psp) {
case POWER_SUPPLY_PROP_STATUS:
if (is_charging)
val->intval = twl4030_bci_state_to_status(state);
else
val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
/* charging must be active for meaningful result */
if (!is_charging)
return -ENODATA;
if (psy->type == POWER_SUPPLY_TYPE_USB) {
ret = twl4030bci_read_adc_val(TWL4030_BCIVBUS);
if (ret < 0)
return ret;
/* BCIVBUS uses ADCIN8, 7/1023 V/step */
val->intval = ret * 6843;
} else {
ret = twl4030bci_read_adc_val(TWL4030_BCIVAC);
if (ret < 0)
return ret;
/* BCIVAC uses ADCIN11, 10/1023 V/step */
val->intval = ret * 9775;
}
break;
case POWER_SUPPLY_PROP_CURRENT_NOW:
if (!is_charging)
return -ENODATA;
/* current measurement is shared between AC and USB */
ret = twl4030_charger_get_current();
if (ret < 0)
return ret;
val->intval = ret;
break;
case POWER_SUPPLY_PROP_ONLINE:
val->intval = is_charging &&
twl4030_bci_state_to_status(state) !=
POWER_SUPPLY_STATUS_NOT_CHARGING;
break;
default:
return -EINVAL;
}
return 0;
}
static enum power_supply_property twl4030_charger_props[] = {
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_ONLINE,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_CURRENT_NOW,
};
static int __init twl4030_bci_probe(struct platform_device *pdev)
{
struct twl4030_bci *bci;
int ret;
int reg;
bci = kzalloc(sizeof(*bci), GFP_KERNEL);
if (bci == NULL)
return -ENOMEM;
bci->dev = &pdev->dev;
bci->irq_chg = platform_get_irq(pdev, 0);
bci->irq_bci = platform_get_irq(pdev, 1);
platform_set_drvdata(pdev, bci);
bci->ac.name = "twl4030_ac";
bci->ac.type = POWER_SUPPLY_TYPE_MAINS;
bci->ac.properties = twl4030_charger_props;
bci->ac.num_properties = ARRAY_SIZE(twl4030_charger_props);
bci->ac.get_property = twl4030_bci_get_property;
ret = power_supply_register(&pdev->dev, &bci->ac);
if (ret) {
dev_err(&pdev->dev, "failed to register ac: %d\n", ret);
goto fail_register_ac;
}
bci->usb.name = "twl4030_usb";
bci->usb.type = POWER_SUPPLY_TYPE_USB;
bci->usb.properties = twl4030_charger_props;
bci->usb.num_properties = ARRAY_SIZE(twl4030_charger_props);
bci->usb.get_property = twl4030_bci_get_property;
ret = power_supply_register(&pdev->dev, &bci->usb);
if (ret) {
dev_err(&pdev->dev, "failed to register usb: %d\n", ret);
goto fail_register_usb;
}
ret = request_threaded_irq(bci->irq_chg, NULL,
twl4030_charger_interrupt, 0, pdev->name, bci);
if (ret < 0) {
dev_err(&pdev->dev, "could not request irq %d, status %d\n",
bci->irq_chg, ret);
goto fail_chg_irq;
}
ret = request_threaded_irq(bci->irq_bci, NULL,
twl4030_bci_interrupt, 0, pdev->name, bci);
if (ret < 0) {
dev_err(&pdev->dev, "could not request irq %d, status %d\n",
bci->irq_bci, ret);
goto fail_bci_irq;
}
INIT_WORK(&bci->work, twl4030_bci_usb_work);
bci->transceiver = otg_get_transceiver();
if (bci->transceiver != NULL) {
bci->otg_nb.notifier_call = twl4030_bci_usb_ncb;
otg_register_notifier(bci->transceiver, &bci->otg_nb);
}
/* Enable interrupts now. */
reg = ~(TWL4030_ICHGLOW | TWL4030_ICHGEOC | TWL4030_TBATOR2 |
TWL4030_TBATOR1 | TWL4030_BATSTS);
ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
TWL4030_INTERRUPTS_BCIIMR1A);
if (ret < 0) {
dev_err(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
goto fail_unmask_interrupts;
}
reg = ~(TWL4030_VBATOV | TWL4030_VBUSOV | TWL4030_ACCHGOV);
ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
TWL4030_INTERRUPTS_BCIIMR2A);
if (ret < 0)
dev_warn(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
twl4030_charger_enable_ac(true);
twl4030_charger_enable_usb(bci, true);
return 0;
fail_unmask_interrupts:
if (bci->transceiver != NULL) {
otg_unregister_notifier(bci->transceiver, &bci->otg_nb);
otg_put_transceiver(bci->transceiver);
}
free_irq(bci->irq_bci, bci);
fail_bci_irq:
free_irq(bci->irq_chg, bci);
fail_chg_irq:
power_supply_unregister(&bci->usb);
fail_register_usb:
power_supply_unregister(&bci->ac);
fail_register_ac:
platform_set_drvdata(pdev, NULL);
kfree(bci);
return ret;
}
static int __exit twl4030_bci_remove(struct platform_device *pdev)
{
struct twl4030_bci *bci = platform_get_drvdata(pdev);
twl4030_charger_enable_ac(false);
twl4030_charger_enable_usb(bci, false);
/* mask interrupts */
twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
TWL4030_INTERRUPTS_BCIIMR1A);
twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
TWL4030_INTERRUPTS_BCIIMR2A);
if (bci->transceiver != NULL) {
otg_unregister_notifier(bci->transceiver, &bci->otg_nb);
otg_put_transceiver(bci->transceiver);
}
free_irq(bci->irq_bci, bci);
free_irq(bci->irq_chg, bci);
power_supply_unregister(&bci->usb);
power_supply_unregister(&bci->ac);
platform_set_drvdata(pdev, NULL);
kfree(bci);
return 0;
}
static struct platform_driver twl4030_bci_driver = {
.driver = {
.name = "twl4030_bci",
.owner = THIS_MODULE,
},
.remove = __exit_p(twl4030_bci_remove),
};
static int __init twl4030_bci_init(void)
{
return platform_driver_probe(&twl4030_bci_driver, twl4030_bci_probe);
}
module_init(twl4030_bci_init);
static void __exit twl4030_bci_exit(void)
{
platform_driver_unregister(&twl4030_bci_driver);
}
module_exit(twl4030_bci_exit);
MODULE_AUTHOR("Gražydas Ignotas");
MODULE_DESCRIPTION("TWL4030 Battery Charger Interface driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:twl4030_bci");
