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

To: Ralf Baechle <ralf@linux-mips.org>
Subject: [RFC][PATCH 23/26] power: Add JZ4740 battery driver.
From: Lars-Peter Clausen <lars@metafoo.de>
Date: Wed, 2 Jun 2010 21:12:29 +0200
Cc: linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, Lars-Peter Clausen <lars@metafoo.de>, Anton Vorontsov <cbouatmailru@gmail.com>
In-reply-to: <1275505397-16758-1-git-send-email-lars@metafoo.de>
References: <1275505397-16758-1-git-send-email-lars@metafoo.de>
Sender: linux-mips-bounce@linux-mips.org
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


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