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Subject[PATCH] power_supply: Add driver for TWL4030/TPS65950 BCI charger
Date
TWL4030/TPS65950 is a multi-function device with integrated charger,
which allows charging from AC or USB. This driver enables the
charger and provides several monitoring functions.

Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
---
For this driver to work, TWL4030-core needs to be patched to use
correct macros so that it registers twl4030_bci platform_device.
I'll send patches for this later.
drivers/power/Kconfig | 7 +
drivers/power/Makefile | 1 +
drivers/power/twl4030_charger.c | 499 +++++++++++++++++++++++++++++++++++++++
3 files changed, 507 insertions(+), 0 deletions(-)
create mode 100644 drivers/power/twl4030_charger.c
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index cea6cef..95d7e60 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -110,4 +110,11 @@ config CHARGER_PCF50633
help
Say Y to include support for NXP PCF50633 Main Battery Charger.

+config CHARGER_TWL4030
+ tristate "OMAP TWL4030 BCI charger driver"
+ depends on TWL4030_CORE
+ default y
+ help
+ Say Y here to enable support for TWL4030 Battery Charge Interface.
+
endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index b96f29d..9cea9b5 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -29,3 +29,4 @@ obj-$(CONFIG_BATTERY_BQ27x00) += bq27x00_battery.o
obj-$(CONFIG_BATTERY_DA9030) += da9030_battery.o
obj-$(CONFIG_BATTERY_MAX17040) += max17040_battery.o
obj-$(CONFIG_CHARGER_PCF50633) += pcf50633-charger.o
+obj-$(CONFIG_CHARGER_TWL4030) += twl4030_charger.o
diff --git a/drivers/power/twl4030_charger.c b/drivers/power/twl4030_charger.c
new file mode 100644
index 0000000..604dd56
--- /dev/null
+++ b/drivers/power/twl4030_charger.c
@@ -0,0 +1,499 @@
+/*
+ * TWL4030/TPS65950 BCI (Battery Charger Interface) driver
+ *
+ * Copyright (C) 2009 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/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/i2c/twl4030.h>
+#include <linux/power_supply.h>
+
+#define REG_BCIMSTATEC 0x02
+#define REG_BCIICHG 0x08
+#define REG_BCIVAC 0x0a
+#define REG_BCIVBUS 0x0c
+#define REG_BCIMFSTS4 0x10
+#define REG_BCICTL1 0x23
+
+#define REG_BOOT_BCI 0x07
+#define REG_STS_HW_CONDITIONS 0x0f
+
+#define BCIAUTOWEN 0x20
+#define CONFIG_DONE 0x10
+#define CVENAC 0x04
+#define BCIAUTOUSB 0x02
+#define BCIAUTOAC 0x01
+#define BCIMSTAT_MASK 0x3F
+#define STS_VBUS 0x80
+#define STS_CHG 0x02
+#define STS_USB_ID 0x04
+#define CGAIN 0x20
+#define USBFASTMCHG 0x04
+
+#define STATEC_USB 0x10
+#define STATEC_AC 0x20
+#define STATEC_STATUS_MASK 0x0f
+#define STATEC_QUICK1 0x02
+#define STATEC_QUICK7 0x07
+#define STATEC_COMPLETE1 0x0b
+#define STATEC_COMPLETE4 0x0e
+
+#define BCI_DELAY 100
+
+struct twl4030_bci_device_info {
+ struct power_supply ac;
+ struct power_supply usb;
+ struct delayed_work bat_work;
+ bool started;
+};
+
+/*
+ * 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 = twl4030_i2c_read_u8(mod_no, &val, reg);
+ if (ret)
+ return ret;
+
+ val &= ~clear;
+ val |= set;
+
+ return twl4030_i2c_write_u8(mod_no, val, reg);
+}
+
+static int twl4030bci_read_adc_val(u8 reg)
+{
+ int ret, temp;
+ u8 val;
+
+ /* read MSB */
+ ret = twl4030_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, &val, reg + 1);
+ if (ret)
+ return ret;
+
+ temp = (int)(val & 0x03) << 8;
+
+ /* read LSB */
+ ret = twl4030_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, &val, reg);
+ if (ret)
+ return ret;
+
+ return temp | val;
+}
+
+static void twl4030bci_power_work(struct work_struct *work)
+{
+ struct twl4030_bci_device_info *di = container_of(work,
+ struct twl4030_bci_device_info, bat_work.work);
+
+ power_supply_changed(&di->ac);
+ power_supply_changed(&di->usb);
+}
+
+/*
+ * Attend to TWL4030 CHG_PRES (AC charger presence) events
+ */
+static irqreturn_t twl4030_charger_interrupt(int irq, void *_di)
+{
+ struct twl4030_bci_device_info *di = _di;
+
+#ifdef CONFIG_LOCKDEP
+ /* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
+ * we don't want and can't tolerate. Although it might be
+ * friendlier not to borrow this thread context...
+ */
+ local_irq_enable();
+#endif
+
+ schedule_delayed_work(&di->bat_work, msecs_to_jiffies(BCI_DELAY));
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * Enable/Disable AC Charge funtionality.
+ */
+static int twl4030_charger_enable_ac(bool enable)
+{
+ int ret;
+
+ if (enable) {
+ /* forcing the field BCIAUTOAC (BOOT_BCI[0) to 1 */
+ ret = twl4030_clear_set(TWL4030_MODULE_PM_MASTER, 0,
+ CONFIG_DONE | BCIAUTOWEN | BCIAUTOAC,
+ REG_BOOT_BCI);
+ } else {
+ /* forcing the field BCIAUTOAC (BOOT_BCI[0) to 0*/
+ ret = twl4030_clear_set(TWL4030_MODULE_PM_MASTER, BCIAUTOAC,
+ CONFIG_DONE | BCIAUTOWEN,
+ REG_BOOT_BCI);
+ }
+
+ return ret;
+}
+
+/*
+ * Check if VBUS power is present
+ */
+static int twl4030_charger_check_vbus(void)
+{
+ int ret;
+ u8 hwsts;
+
+ ret = twl4030_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &hwsts,
+ REG_STS_HW_CONDITIONS);
+ if (ret) {
+ pr_err("twl4030_bci: error reading STS_HW_CONDITIONS\n");
+ return ret;
+ }
+
+ pr_debug("check_vbus: HW_CONDITIONS %02x\n", hwsts);
+
+ /* in case we also have STS_USB_ID, VBUS is driven by TWL itself */
+ if ((hwsts & STS_VBUS) && !(hwsts & STS_USB_ID))
+ return 1;
+
+ return 0;
+}
+
+/*
+ * Enable/Disable USB Charge funtionality.
+ */
+static int twl4030_charger_enable_usb(bool enable)
+{
+ int ret;
+
+ if (enable) {
+ /* Check for USB charger conneted */
+ ret = twl4030_charger_check_vbus();
+ if (ret < 0)
+ return ret;
+
+ if (!ret)
+ return -ENXIO;
+
+ /* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */
+ ret = twl4030_clear_set(TWL4030_MODULE_PM_MASTER, 0,
+ CONFIG_DONE | BCIAUTOWEN | BCIAUTOUSB,
+ REG_BOOT_BCI);
+ if (ret)
+ return ret;
+
+ /* forcing USBFASTMCHG(BCIMFSTS4[2]) to 1 */
+ ret = twl4030_clear_set(TWL4030_MODULE_MAIN_CHARGE, 0,
+ USBFASTMCHG, REG_BCIMFSTS4);
+ } else {
+ ret = twl4030_clear_set(TWL4030_MODULE_PM_MASTER, BCIAUTOUSB,
+ CONFIG_DONE | BCIAUTOWEN, REG_BOOT_BCI);
+ }
+
+ return ret;
+}
+
+/*
+ * Return voltage (valid while charging only)
+ * 10 bit ADC (0...0x3ff) scales to 0...6V
+ */
+static int twl4030_get_voltage(int reg)
+{
+ int ret = twl4030bci_read_adc_val(reg);
+ if (ret < 0)
+ return ret;
+
+ return 6000 * ret / 1023;
+}
+
+/*
+ * 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(REG_BCIICHG);
+ if (curr < 0)
+ return curr;
+
+ ret = twl4030_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, &bcictl1,
+ REG_BCICTL1);
+ if (ret)
+ return ret;
+
+ ret = (curr * 16618 - 850 * 10000) / 10000;
+ if (bcictl1 & CGAIN)
+ ret *= 2;
+
+ return ret;
+}
+
+/*
+ * Returns the main charge FSM state
+ * Or < 0 on failure.
+ */
+static int twl4030bci_state(void)
+{
+ int ret;
+ u8 state;
+
+ ret = twl4030_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE,
+ &state, REG_BCIMSTATEC);
+ if (ret) {
+ pr_err("twl4030_bci: error reading BCIMSTATEC\n");
+ return ret;
+ }
+
+ pr_debug("state: %02x\n", state);
+
+ return state & BCIMSTAT_MASK;
+}
+
+static int twl4030_bci_state_to_status(int state)
+{
+ state &= STATEC_STATUS_MASK;
+ if (STATEC_QUICK1 <= state && state <= STATEC_QUICK7)
+ return POWER_SUPPLY_STATUS_CHARGING;
+ else if (STATEC_COMPLETE1 <= state && state <= STATEC_COMPLETE4)
+ return POWER_SUPPLY_STATUS_FULL;
+ else
+ return POWER_SUPPLY_STATUS_NOT_CHARGING;
+}
+
+static int twl4030_charger_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ int is_charging;
+ int voltage_reg;
+ int state;
+ int ret;
+
+ state = twl4030bci_state();
+ if (state < 0)
+ return state;
+
+ if (psy->type == POWER_SUPPLY_TYPE_USB) {
+ is_charging = state & STATEC_USB;
+ voltage_reg = REG_BCIVBUS;
+ } else {
+ is_charging = state & STATEC_AC;
+ voltage_reg = REG_BCIVAC;
+ }
+
+ 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) {
+ val->intval = 0;
+ break;
+ }
+ ret = twl4030_get_voltage(voltage_reg);
+ if (ret < 0)
+ return ret;
+ val->intval = ret;
+ break;
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ if (!is_charging) {
+ val->intval = 0;
+ break;
+ }
+ /* 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 struct twl4030_bci_device_info twl4030_bci = {
+ .ac = {
+ .name = "twl4030_ac",
+ .type = POWER_SUPPLY_TYPE_MAINS,
+ .properties = twl4030_charger_props,
+ .num_properties = ARRAY_SIZE(twl4030_charger_props),
+ .get_property = twl4030_charger_get_property,
+ },
+ .usb = {
+ .name = "twl4030_usb",
+ .type = POWER_SUPPLY_TYPE_USB,
+ .properties = twl4030_charger_props,
+ .num_properties = ARRAY_SIZE(twl4030_charger_props),
+ .get_property = twl4030_charger_get_property,
+ },
+};
+
+/*
+ * called by TWL4030 USB transceiver driver on USB_PRES interrupt.
+ */
+int twl4030charger_usb_en(int enable)
+{
+ if (twl4030_bci.started)
+ schedule_delayed_work(&twl4030_bci.bat_work,
+ msecs_to_jiffies(BCI_DELAY));
+
+ return twl4030_charger_enable_usb(enable);
+}
+
+static int __devinit twl4030_bci_probe(struct platform_device *pdev)
+{
+ int irq;
+ int ret;
+
+ twl4030_charger_enable_ac(true);
+ twl4030_charger_enable_usb(true);
+
+ irq = platform_get_irq(pdev, 0);
+
+ /* CHG_PRES irq */
+ ret = request_irq(irq, twl4030_charger_interrupt,
+ 0, pdev->name, &twl4030_bci);
+ if (ret) {
+ dev_err(&pdev->dev, "could not request irq %d, status %d\n",
+ irq, ret);
+ goto fail_chg_irq;
+ }
+
+ ret = power_supply_register(&pdev->dev, &twl4030_bci.ac);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register ac: %d\n", ret);
+ goto fail_register_ac;
+ }
+
+ ret = power_supply_register(&pdev->dev, &twl4030_bci.usb);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register usb: %d\n", ret);
+ goto fail_register_usb;
+ }
+
+ platform_set_drvdata(pdev, &twl4030_bci);
+
+ INIT_DELAYED_WORK_DEFERRABLE(&twl4030_bci.bat_work,
+ twl4030bci_power_work);
+ schedule_delayed_work(&twl4030_bci.bat_work,
+ msecs_to_jiffies(BCI_DELAY));
+ twl4030_bci.started = true;
+
+ return 0;
+
+fail_register_usb:
+ power_supply_unregister(&twl4030_bci.ac);
+fail_register_ac:
+ free_irq(irq, &twl4030_bci);
+fail_chg_irq:
+ twl4030_charger_enable_ac(false);
+ twl4030_charger_enable_usb(false);
+
+ return ret;
+}
+
+static int __devexit twl4030_bci_remove(struct platform_device *pdev)
+{
+ struct twl4030_bci_device_info *di = platform_get_drvdata(pdev);
+ int irq = platform_get_irq(pdev, 0);
+
+ di->started = false;
+ twl4030_charger_enable_ac(false);
+ twl4030_charger_enable_usb(false);
+
+ free_irq(irq, di);
+
+ flush_scheduled_work();
+ power_supply_unregister(&di->ac);
+ power_supply_unregister(&di->usb);
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int twl4030_bci_suspend(struct platform_device *pdev,
+ pm_message_t state)
+{
+ /* flush all pending status updates */
+ flush_scheduled_work();
+ return 0;
+}
+
+static int twl4030_bci_resume(struct platform_device *pdev)
+{
+ struct twl4030_bci_device_info *di = platform_get_drvdata(pdev);
+
+ /* things may have changed while we were away */
+ schedule_delayed_work(&di->bat_work, msecs_to_jiffies(BCI_DELAY));
+ return 0;
+}
+#else
+#define twl4030_bci_suspend NULL
+#define twl4030_bci_resume NULL
+#endif /* CONFIG_PM */
+
+static struct platform_driver twl4030_bci_driver = {
+ .probe = twl4030_bci_probe,
+ .remove = __devexit_p(twl4030_bci_remove),
+ .suspend = twl4030_bci_suspend,
+ .resume = twl4030_bci_resume,
+ .driver = {
+ .name = "twl4030_bci",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init twl4030_bci_init(void)
+{
+ return platform_driver_register(&twl4030_bci_driver);
+}
+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("Gražvydas Ignotas");
+MODULE_DESCRIPTION("TWL4030 Battery Charger Interface driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:twl4030_bci");
--
1.6.3.3
--
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