[RFC][PATCH 23/26] power: Add JZ4740 battery driver.

[Lars-Peter Clausen <lars@metafoo.de>]

This patch adds support for the battery voltage measurement part of the JZ4740
ADC unit.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Anton Vorontsov <cbouatmailru@gmail.com>
---
 drivers/power/Kconfig                |   11 +
 drivers/power/Makefile               |    1 +
 drivers/power/jz4740-battery.c       |  359 ++++++++++++++++++++++++++++++++++
 include/linux/power/jz4740-battery.h |   24 +++
 4 files changed, 395 insertions(+), 0 deletions(-)
 create mode 100644 drivers/power/jz4740-battery.c
 create mode 100644 include/linux/power/jz4740-battery.h

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 8e9ba17..80bbd0d 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -142,4 +142,15 @@ config CHARGER_PCF50633
 	help
 	 Say Y to include support for NXP PCF50633 Main Battery Charger.
 
+config BATTERY_JZ4740
+	tristate "Ingenic JZ4740 battery"
+	depends on MACH_JZ4740
+	depends on SENSORS_JZ4740
+	help
+	  Say Y to enable support for the battery on Ingenic JZ4740 based
+	  boards.
+
+	  This driver can be build as a module. If so, the module will be
+	  called jz4740-battery.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 0005080..cf95009 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -34,3 +34,4 @@ obj-$(CONFIG_BATTERY_DA9030)	+= da9030_battery.o
 obj-$(CONFIG_BATTERY_MAX17040)	+= max17040_battery.o
 obj-$(CONFIG_BATTERY_Z2)	+= z2_battery.o
 obj-$(CONFIG_CHARGER_PCF50633)	+= pcf50633-charger.o
+obj-$(CONFIG_BATTERY_JZ4740)	+= jz4740-battery.o
diff --git a/drivers/power/jz4740-battery.c b/drivers/power/jz4740-battery.c
new file mode 100644
index 0000000..9eadb36
--- /dev/null
+++ b/drivers/power/jz4740-battery.c
@@ -0,0 +1,359 @@
+/*
+ * Battery measurement code for Ingenic JZ SOC.
+ *
+ * Copyright (C) 2009 Jiejing Zhang <kzjeef@gmail.com>
+ * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * based on tosa_battery.c
+ *
+ * Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.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/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/power_supply.h>
+
+#include <linux/power/jz4740-battery.h>
+#include <linux/jz4740-adc.h>
+
+struct jz_battery {
+	struct jz_battery_platform_data *pdata;
+
+	int charge_irq;
+
+	int status;
+	long voltage;
+
+	struct power_supply battery;
+	struct delayed_work work;
+};
+
+static inline struct jz_battery *psy_to_jz_battery(struct power_supply *psy)
+{
+	return container_of(psy, struct jz_battery, battery);
+}
+
+static long jz_battery_read_voltage(struct jz_battery *jz_battery)
+{
+	struct device *adc = jz_battery->battery.dev->parent->parent;
+	enum jz_adc_battery_scale scale;
+
+	if (jz_battery->pdata->info.voltage_max_design > 2500000)
+		scale = JZ_ADC_BATTERY_SCALE_7V5;
+	else
+		scale = JZ_ADC_BATTERY_SCALE_2V5;
+
+	return jz4740_adc_read_battery_voltage(adc, scale);
+}
+
+static int jz_battery_get_capacity(struct power_supply *psy)
+{
+	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
+	struct power_supply_info *info = &jz_battery->pdata->info;
+	long voltage;
+	int ret;
+	int voltage_span;
+
+	voltage = jz_battery_read_voltage(jz_battery);
+
+	if (voltage < 0)
+		return voltage;
+
+	voltage_span = info->voltage_max_design - info->voltage_min_design;
+	ret = ((voltage - info->voltage_min_design) * 100) / voltage_span;
+
+	if (ret > 100)
+		ret = 100;
+	else if (ret < 0)
+		ret = 0;
+
+	return ret;
+}
+
+static int jz_battery_get_property(struct power_supply *psy,
+				enum power_supply_property psp,
+				union power_supply_propval *val)
+{
+	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
+	struct power_supply_info *info = &jz_battery->pdata->info;
+	long voltage;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		val->intval = jz_battery->status;
+		break;
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		val->intval = jz_battery->pdata->info.technology;
+		break;
+	case POWER_SUPPLY_PROP_HEALTH:
+		voltage = jz_battery_read_voltage(jz_battery);
+		if (voltage < info->voltage_min_design)
+			val->intval = POWER_SUPPLY_HEALTH_DEAD;
+		else
+			val->intval = POWER_SUPPLY_HEALTH_GOOD;
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		val->intval = jz_battery_get_capacity(psy);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		val->intval = jz_battery_read_voltage(jz_battery);
+		if (val->intval < 0)
+			return val->intval;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		val->intval = info->voltage_max_design;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+		val->intval = info->voltage_min_design;
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void jz_battery_external_power_changed(struct power_supply *psy)
+{
+	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
+
+	cancel_delayed_work(&jz_battery->work);
+	schedule_delayed_work(&jz_battery->work, 0);
+}
+
+static irqreturn_t jz_battery_charge_irq(int irq, void *data)
+{
+	struct jz_battery *jz_battery = data;
+
+	cancel_delayed_work(&jz_battery->work);
+	schedule_delayed_work(&jz_battery->work, 0);
+
+	return IRQ_HANDLED;
+}
+
+static void jz_battery_update(struct jz_battery *jz_battery)
+{
+	int status;
+	long voltage;
+	long voltage_difference;
+	bool has_changed = 0;
+
+	if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
+		int is_charging;
+
+		is_charging = gpio_get_value(jz_battery->pdata->gpio_charge);
+		is_charging ^= jz_battery->pdata->gpio_charge_active_low;
+		if (is_charging)
+			status = POWER_SUPPLY_STATUS_CHARGING;
+		else
+			status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+
+		if (status != jz_battery->status) {
+			jz_battery->status = status;
+			has_changed = 1;
+		}
+	}
+
+	voltage = jz_battery_read_voltage(jz_battery);
+	voltage_difference = voltage - jz_battery->voltage;
+	if (voltage_difference > 50000 || voltage_difference < 50000) {
+		jz_battery->voltage = voltage;
+		has_changed = 1;
+	}
+	if (has_changed)
+		power_supply_changed(&jz_battery->battery);
+}
+
+static enum power_supply_property jz_battery_properties[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+	POWER_SUPPLY_PROP_PRESENT,
+};
+
+static void jz_battery_work(struct work_struct *work)
+{
+	/* Too small interval will increase system workload */
+	const int interval = HZ * 30;
+	struct jz_battery *jz_battery = container_of(work, struct jz_battery,
+					    work.work);
+
+	jz_battery_update(jz_battery);
+	schedule_delayed_work(&jz_battery->work, interval);
+}
+
+static int __devinit jz_battery_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct jz_battery_platform_data *pdata = pdev->dev.platform_data;
+	struct jz_battery *jz_battery;
+	struct power_supply *battery;
+
+	if (!pdev->dev.platform_data) {
+		dev_err(&pdev->dev, "No platform data\n");
+		return -EINVAL;
+	}
+
+	jz_battery = kzalloc(sizeof(*jz_battery), GFP_KERNEL);
+
+	if (!jz_battery) {
+		dev_err(&pdev->dev, "Failed to allocate driver structure\n");
+		return -ENOMEM;
+	}
+
+	battery = &jz_battery->battery;
+	battery->name = pdata->info.name;
+	battery->type = POWER_SUPPLY_TYPE_BATTERY;
+	battery->properties	= jz_battery_properties;
+	battery->num_properties	= ARRAY_SIZE(jz_battery_properties);
+	battery->get_property = jz_battery_get_property;
+	battery->external_power_changed = jz_battery_external_power_changed;
+	battery->use_for_apm = 1;
+
+	jz_battery->pdata = pdata;
+
+	INIT_DELAYED_WORK(&jz_battery->work, jz_battery_work);
+
+	if (gpio_is_valid(pdata->gpio_charge)) {
+		ret = gpio_request(pdata->gpio_charge, dev_name(&pdev->dev));
+		if (ret) {
+			dev_err(&pdev->dev, "charger state gpio request failed.\n");
+			goto err_free;
+		}
+		ret = gpio_direction_input(pdata->gpio_charge);
+		if (ret) {
+			dev_err(&pdev->dev, "charger state gpio set direction failed.\n");
+			goto err_free_gpio;
+		}
+
+		jz_battery->charge_irq = gpio_to_irq(pdata->gpio_charge);
+
+		if (jz_battery->charge_irq >= 0) {
+			ret = request_irq(jz_battery->charge_irq,
+				    jz_battery_charge_irq,
+				    IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+				    dev_name(&pdev->dev), jz_battery);
+			if (ret) {
+				dev_err(&pdev->dev, "Failed to request charge irq: %d\n", ret);
+				goto err_free_gpio;
+			}
+		}
+	} else {
+		jz_battery->charge_irq = -1;
+	}
+
+
+	ret = power_supply_register(&pdev->dev, &jz_battery->battery);
+	if (ret) {
+		dev_err(&pdev->dev, "power supply battery register failed.\n");
+		goto err_free_irq;
+	}
+
+	platform_set_drvdata(pdev, jz_battery);
+	schedule_delayed_work(&jz_battery->work, 0);
+
+	return 0;
+
+err_free_irq:
+	if (jz_battery->charge_irq >= 0)
+		free_irq(jz_battery->charge_irq, jz_battery);
+err_free_gpio:
+	if (gpio_is_valid(pdata->gpio_charge))
+		gpio_free(jz_battery->pdata->gpio_charge);
+err_free:
+	kfree(jz_battery);
+	return ret;
+}
+
+static int __devexit jz_battery_remove(struct platform_device *pdev)
+{
+	struct jz_battery *jz_battery = platform_get_drvdata(pdev);
+
+	cancel_delayed_work_sync(&jz_battery->work);
+
+	if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
+		if (jz_battery->charge_irq >= 0)
+			free_irq(jz_battery->charge_irq, jz_battery);
+		gpio_free(jz_battery->pdata->gpio_charge);
+	}
+
+	power_supply_unregister(&jz_battery->battery);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int jz_battery_suspend(struct device *dev)
+{
+	struct jz_battery *jz_battery = dev_get_drvdata(dev);
+
+	cancel_delayed_work_sync(&jz_battery->work);
+	jz_battery->status =  POWER_SUPPLY_STATUS_UNKNOWN;
+
+	return 0;
+}
+
+static int jz_battery_resume(struct device *dev)
+{
+	struct jz_battery *jz_battery = dev_get_drvdata(dev);
+
+	schedule_delayed_work(&jz_battery->work, 0);
+
+	return 0;
+}
+
+static const struct dev_pm_ops jz_battery_pm_ops = {
+	.suspend	= jz_battery_suspend,
+	.resume		= jz_battery_resume,
+};
+
+#define JZ_BATTERY_PM_OPS (&jz_battery_pm_ops)
+
+#else
+#define JZ_BATTERY_PM_OPS NULL
+#endif
+
+static struct platform_driver jz_battery_driver = {
+	.probe		= jz_battery_probe,
+	.remove		= __devexit_p(jz_battery_remove),
+	.driver = {
+		.name = "jz4740-battery",
+		.owner = THIS_MODULE,
+		.pm = JZ_BATTERY_PM_OPS,
+	},
+};
+
+static int __init jz_battery_init(void)
+{
+	return platform_driver_register(&jz_battery_driver);
+}
+module_init(jz_battery_init);
+
+static void __exit jz_battery_exit(void)
+{
+	platform_driver_unregister(&jz_battery_driver);
+}
+module_exit(jz_battery_exit);
+
+MODULE_ALIAS("platform:jz4740-battery");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("JZ4740 SoC battery driver");
diff --git a/include/linux/power/jz4740-battery.h b/include/linux/power/jz4740-battery.h
new file mode 100644
index 0000000..19c9610
--- /dev/null
+++ b/include/linux/power/jz4740-battery.h
@@ -0,0 +1,24 @@
+/*
+ *  Copyright (C) 2009, Jiejing Zhang <kzjeef@gmail.com>
+ *
+ *  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.
+ *
+ *  You should have received a copy of the  GNU General Public License along
+ *  with this program; if not, write  to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#ifndef __JZ4740_BATTERY_H
+#define __JZ4740_BATTERY_H
+
+struct jz_battery_platform_data {
+	struct power_supply_info info;
+	int gpio_charge;	/* GPIO port of Charger state */
+	int gpio_charge_active_low;
+};
+
+#endif
-- 
1.5.6.5