[PATCH v3] power_supply: Add driver for TWL4030/TPS65950 BCI charger

[Grazvydas Ignotas]

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.

Tested on OMAP3 Pandora board.

Signed-off-by: Grazvydas Ignotas <notasas@xxxxxxxxx>
---
This is v3 of BCI charger driver I first sent nearly a year ago [1].
I've updated it to use the new OTG notifiers for VBUS notifications,
however it still is not able to determine charge current to use.
For that reason there is now a temporary module param to enable USB
charging, until I can figure out how to get that info from the gadget
stack (hopefully Felipe can help me here).
Besides that it now uses threaded interrupts and makes use of charge
state change interrupt to notify power supply core.

For this driver to work, twl-core needs to be patched to register
correct platform device, and twl4030-irq needs to set COR bit
correctly (will send those patches to mfd).

[1] http://marc.info/?l=linux-omap&m=125933316000333&w=2

 drivers/power/Kconfig           |    6 +
 drivers/power/Makefile          |    1 +
 drivers/power/twl4030_charger.c |  575 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 582 insertions(+), 0 deletions(-)
 create mode 100644 drivers/power/twl4030_charger.c

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 4d9a637..11eec62 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -180,4 +180,10 @@ config CHARGER_ISP1704
 	  Say Y to enable support for USB Charger Detection with
 	  ISP1707/ISP1704 USB transceivers.
 
+config CHARGER_TWL4030
+	tristate "OMAP TWL4030 BCI charger driver"
+	depends on TWL4030_CORE
+	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 2799a84..695e54f 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -39,3 +39,4 @@ obj-$(CONFIG_CHARGER_PCF50633)	+= pcf50633-charger.o
 obj-$(CONFIG_BATTERY_JZ4740)	+= jz4740-battery.o
 obj-$(CONFIG_BATTERY_INTEL_MID)	+= intel_mid_battery.o
 obj-$(CONFIG_CHARGER_ISP1704)	+= isp1704_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..75ed029
--- /dev/null
+++ b/drivers/power/twl4030_charger.c
@@ -0,0 +1,575 @@
+/*
+ * TWL4030/TPS65950 BCI (Battery Charger Interface) driver
+ *
+ * Copyright (C) 2010 Gražvydas Ignotas <notasas@xxxxxxxxx>
+ *
+ * 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;
+	int			irq_chg;
+	int			irq_bci;
+};
+
+/*
+ * 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 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);
+
+	switch (val) {
+	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;
+	}
+
+	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 __devinit 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);
+
+	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;
+	}
+
+	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;
+	}
+
+#ifdef CONFIG_USB_OTG_UTILS
+	bci->transceiver = otg_get_transceiver();
+#endif
+	if (bci->transceiver != NULL) {
+		bci->otg_nb.notifier_call = twl4030_bci_usb_ncb;
+		blocking_notifier_chain_register(&bci->transceiver->notifier,
+			&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:
+#ifdef CONFIG_USB_OTG_UTILS
+	if (bci->transceiver != NULL) {
+		blocking_notifier_chain_unregister(&bci->transceiver->notifier,
+			&bci->otg_nb);
+		otg_put_transceiver(bci->transceiver);
+	}
+#endif
+	power_supply_unregister(&bci->usb);
+fail_register_usb:
+	power_supply_unregister(&bci->ac);
+fail_register_ac:
+	platform_set_drvdata(pdev, NULL);
+	free_irq(bci->irq_bci, bci);
+fail_bci_irq:
+	free_irq(bci->irq_chg, bci);
+fail_chg_irq:
+	kfree(bci);
+
+	return ret;
+}
+
+static int __devexit 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);
+
+#ifdef CONFIG_USB_OTG_UTILS
+	if (bci->transceiver != NULL) {
+		blocking_notifier_chain_unregister(&bci->transceiver->notifier,
+			&bci->otg_nb);
+		otg_put_transceiver(bci->transceiver);
+	}
+#endif
+	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 = {
+	.probe		= twl4030_bci_probe,
+	.remove		= __devexit_p(twl4030_bci_remove),
+	.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("Gražydas Ignotas");
+MODULE_DESCRIPTION("TWL4030 Battery Charger Interface driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:twl4030_bci");
-- 
1.6.3.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/