[ARM] 5155/1: PalmTX battery monitor

This patch adds battery monitoring driver for PalmTX.
It can read voltage from the battery and temperature.
It also monitors charging/discharging status.
Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-pxa/palmtx.c

@@ -22,6 +22,7 @@
 #include <linux/irq.h>
 #include <linux/gpio_keys.h>
 #include <linux/input.h>
+#include <linux/pda_power.h>
 #include <linux/pwm_backlight.h>
 #include <linux/gpio.h>
 
@@ -278,6 +279,66 @@ static struct pxa2xx_udc_mach_info palmtx_udc_info __initdata = {
 	.udc_command		= palmtx_udc_command,
 };
 
+/******************************************************************************
+ * Power supply
+ ******************************************************************************/
+static int power_supply_init(struct device *dev)
+{
+	int ret;
+
+	ret = gpio_request(GPIO_NR_PALMTX_POWER_DETECT, "CABLE_STATE_AC");
+	if (ret)
+		goto err_cs_ac;
+
+	ret = gpio_request(GPIO_NR_PALMTX_USB_DETECT_N, "CABLE_STATE_USB");
+	if (ret)
+		goto err_cs_usb;
+
+	return 0;
+
+err_cs_usb:
+	gpio_free(GPIO_NR_PALMTX_POWER_DETECT);
+err_cs_ac:
+	return ret;
+}
+
+static int palmtx_is_ac_online(void)
+{
+	return gpio_get_value(GPIO_NR_PALMTX_POWER_DETECT);
+}
+
+static int palmtx_is_usb_online(void)
+{
+	return !gpio_get_value(GPIO_NR_PALMTX_USB_DETECT_N);
+}
+
+static void power_supply_exit(struct device *dev)
+{
+	gpio_free(GPIO_NR_PALMTX_USB_DETECT_N);
+	gpio_free(GPIO_NR_PALMTX_POWER_DETECT);
+}
+
+static char *palmtx_supplicants[] = {
+	"main-battery",
+};
+
+static struct pda_power_pdata power_supply_info = {
+	.init            = power_supply_init,
+	.is_ac_online    = palmtx_is_ac_online,
+	.is_usb_online   = palmtx_is_usb_online,
+	.exit            = power_supply_exit,
+	.supplied_to     = palmtx_supplicants,
+	.num_supplicants = ARRAY_SIZE(palmtx_supplicants),
+};
+
+static struct platform_device power_supply = {
+	.name = "pda-power",
+	.id   = -1,
+	.dev  = {
+		.platform_data = &power_supply_info,
+	},
+};
+
 /******************************************************************************
  * Framebuffer
  ******************************************************************************/
@@ -312,6 +373,7 @@ static struct platform_device *devices[] __initdata = {
 	&palmtx_pxa_keys,
 #endif
 	&palmtx_backlight,
+	&power_supply,
 };
 
 static struct map_desc palmtx_io_desc[] __initdata = {

drivers/power/Kconfig

@@ -49,4 +49,10 @@ config BATTERY_OLPC
 	help
 	  Say Y to enable support for the battery on the OLPC laptop.
 
+config BATTERY_PALMTX
+	tristate "Palm T|X battery"
+	depends on MACH_PALMTX
+	help
+	  Say Y to enable support for the battery in Palm T|X.
+
 endif # POWER_SUPPLY

drivers/power/Makefile

@@ -20,3 +20,4 @@ obj-$(CONFIG_APM_POWER)		+= apm_power.o
 obj-$(CONFIG_BATTERY_DS2760)	+= ds2760_battery.o
 obj-$(CONFIG_BATTERY_PMU)	+= pmu_battery.o
 obj-$(CONFIG_BATTERY_OLPC)	+= olpc_battery.o
+obj-$(CONFIG_BATTERY_PALMTX)	+= palmtx_battery.o

drivers/power/palmtx_battery.c

+/*
+ * linux/drivers/power/palmtx_battery.c
+ *
+ * Battery measurement code for Palm T|X Handheld computer
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/power_supply.h>
+#include <linux/wm97xx.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+
+#include <asm/mach-types.h>
+#include <asm/arch/palmtx.h>
+
+static DEFINE_MUTEX(bat_lock);
+static struct work_struct bat_work;
+struct mutex work_lock;
+int bat_status = POWER_SUPPLY_STATUS_DISCHARGING;
+
+static unsigned long palmtx_read_bat(struct power_supply *bat_ps)
+{
+	return wm97xx_read_aux_adc(bat_ps->dev->parent->driver_data,
+				    WM97XX_AUX_ID3) * 1000 / 414;
+}
+
+static unsigned long palmtx_read_temp(struct power_supply *bat_ps)
+{
+	return wm97xx_read_aux_adc(bat_ps->dev->parent->driver_data,
+				    WM97XX_AUX_ID2);
+}
+
+static int palmtx_bat_get_property(struct power_supply *bat_ps,
+			    enum power_supply_property psp,
+			    union power_supply_propval *val)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		val->intval = bat_status;
+		break;
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		val->intval = POWER_SUPPLY_TECHNOLOGY_LIPO;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		val->intval = palmtx_read_bat(bat_ps);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX:
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		val->intval = PALMTX_BAT_MAX_VOLTAGE;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+		val->intval = PALMTX_BAT_MIN_VOLTAGE;
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		val->intval = palmtx_read_temp(bat_ps);
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void palmtx_bat_external_power_changed(struct power_supply *bat_ps)
+{
+	schedule_work(&bat_work);
+}
+
+static char *status_text[] = {
+	[POWER_SUPPLY_STATUS_UNKNOWN] =		"Unknown",
+	[POWER_SUPPLY_STATUS_CHARGING] =	"Charging",
+	[POWER_SUPPLY_STATUS_DISCHARGING] =	"Discharging",
+};
+
+static void palmtx_bat_update(struct power_supply *bat_ps)
+{
+	int old_status = bat_status;
+
+	mutex_lock(&work_lock);
+
+	bat_status = gpio_get_value(GPIO_NR_PALMTX_POWER_DETECT) ?
+				    POWER_SUPPLY_STATUS_CHARGING :
+				    POWER_SUPPLY_STATUS_DISCHARGING;
+
+	if (old_status != bat_status) {
+		pr_debug("%s %s -> %s\n", bat_ps->name,
+				status_text[old_status],
+				status_text[bat_status]);
+		power_supply_changed(bat_ps);
+	}
+
+	mutex_unlock(&work_lock);
+}
+
+static enum power_supply_property palmtx_bat_main_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+	POWER_SUPPLY_PROP_TEMP,
+	POWER_SUPPLY_PROP_PRESENT,
+};
+
+struct power_supply bat_ps = {
+	.name			= "main-battery",
+	.type			= POWER_SUPPLY_TYPE_BATTERY,
+	.properties		= palmtx_bat_main_props,
+	.num_properties		= ARRAY_SIZE(palmtx_bat_main_props),
+	.get_property		= palmtx_bat_get_property,
+	.external_power_changed = palmtx_bat_external_power_changed,
+	.use_for_apm		= 1,
+};
+
+static void palmtx_bat_work(struct work_struct *work)
+{
+	palmtx_bat_update(&bat_ps);
+}
+
+#ifdef CONFIG_PM
+static int palmtx_bat_suspend(struct platform_device *dev, pm_message_t state)
+{
+	flush_scheduled_work();
+	return 0;
+}
+
+static int palmtx_bat_resume(struct platform_device *dev)
+{
+	schedule_work(&bat_work);
+	return 0;
+}
+#else
+#define palmtx_bat_suspend NULL
+#define palmtx_bat_resume NULL
+#endif
+
+static int __devinit palmtx_bat_probe(struct platform_device *dev)
+{
+	int ret = 0;
+
+	if (!machine_is_palmtx())
+		return -ENODEV;
+
+	mutex_init(&work_lock);
+
+	INIT_WORK(&bat_work, palmtx_bat_work);
+
+	ret = power_supply_register(&dev->dev, &bat_ps);
+	if (!ret)
+		schedule_work(&bat_work);
+
+	return ret;
+}
+
+static int __devexit palmtx_bat_remove(struct platform_device *dev)
+{
+	power_supply_unregister(&bat_ps);
+	return 0;
+}
+
+static struct platform_driver palmtx_bat_driver = {
+	.driver.name	= "wm97xx-battery",
+	.driver.owner	= THIS_MODULE,
+	.probe		= palmtx_bat_probe,
+	.remove		= __devexit_p(palmtx_bat_remove),
+	.suspend	= palmtx_bat_suspend,
+	.resume		= palmtx_bat_resume,
+};
+
+static int __init palmtx_bat_init(void)
+{
+	return platform_driver_register(&palmtx_bat_driver);
+}
+
+static void __exit palmtx_bat_exit(void)
+{
+	platform_driver_unregister(&palmtx_bat_driver);
+}
+
+module_init(palmtx_bat_init);
+module_exit(palmtx_bat_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
+MODULE_DESCRIPTION("Palm T|X battery driver");