gta02: add support for platform_battery
authorPaul Fertser <fercerpav@gmail.com>
Wed, 4 Nov 2009 11:27:52 +0000 (14:27 +0300)
committerLars-Peter Clausen <lars@metafoo.de>
Mon, 17 May 2010 22:53:35 +0000 (00:53 +0200)
This adds support for platform_battery driver which allows to specify a set
of power supply properties and callbacks to acquire them. It is needed to
support dumb batteries where all the information about their status can
only be obtained by platform-specific actions such as specific ADC
measurements, some guessimation etc.

Signed-off-by: Paul Fertser <fercerpav@gmail.com>
arch/arm/mach-s3c2440/mach-gta02.c

index 3f1da15..e8ac76b 100644 (file)
 
 #include <linux/hdq.h>
 #include <linux/bq27000_battery.h>
+#include <linux/platform_battery.h>
 
 #include <linux/jbt6k74.h>
 #include <linux/glamofb.h>
@@ -907,6 +908,117 @@ struct platform_device bq27000_battery_device = {
        },
 };
 
+/* Platform battery */
+
+/* Capacity of a typical BL-5C dumb battery */
+#define GTA02_BAT_CHARGE_FULL  850000
+
+static int gta02_bat_voltscale(int volt)
+{
+       /* This table is suggested by SpeedEvil based on analysis of
+        * experimental data */
+       static const int lut[][2] = {
+               { 4120, 100 },
+               { 3900, 60 },
+               { 3740, 25 },
+               { 3600, 5 },
+               { 3000, 0 } };
+       int i, res = 0;
+
+       if (volt > lut[0][0])
+               res = lut[0][1];
+       else
+               for (i = 0; lut[i][1]; i++) {
+                       if (volt <= lut[i][0] && volt >= lut[i+1][0]) {
+                               res = lut[i][1] - (lut[i][0]-volt)*
+                                       (lut[i][1]-lut[i+1][1])/
+                                       (lut[i][0]-lut[i+1][0]);
+                               break;
+                       }
+               }
+       return res;
+}
+
+static int gta02_bat_get_voltage(void)
+{
+       struct pcf50633 *pcf = gta02_pcf;
+       u16 adc, mv = 0;
+       adc = pcf50633_adc_sync_read(pcf,
+               PCF50633_ADCC1_MUX_BATSNS_RES,
+               PCF50633_ADCC1_AVERAGE_16);
+       /* The formula from DS is for divide-by-two mode, current driver uses
+       divide-by-three */
+       mv = (adc * 6000) / 1023;
+       return mv * 1000;
+}
+
+static int gta02_bat_get_present(void)
+{
+       /* There is no reliable way to tell if it is present or not */
+       return 1;
+}
+
+static int gta02_bat_get_status(void)
+{
+#ifdef CONFIG_CHARGER_PCF50633
+       if (gta02_get_charger_active_status())
+               return POWER_SUPPLY_STATUS_CHARGING;
+       else
+               return POWER_SUPPLY_STATUS_DISCHARGING;
+#else
+       return POWER_SUPPLY_STATUS_UNKNOWN;
+#endif
+}
+
+static int gta02_bat_get_capacity(void)
+{
+       return gta02_bat_voltscale(gta02_bat_get_voltage()/1000);
+}
+
+static int gta02_bat_get_charge_full(void)
+{
+       return GTA02_BAT_CHARGE_FULL;
+}
+
+static int gta02_bat_get_charge_now(void)
+{
+       return gta02_bat_get_capacity() * gta02_bat_get_charge_full() / 100;
+}
+
+static enum power_supply_property gta02_platform_bat_properties[] = {
+       POWER_SUPPLY_PROP_PRESENT,
+       POWER_SUPPLY_PROP_STATUS,
+       POWER_SUPPLY_PROP_VOLTAGE_NOW,
+       POWER_SUPPLY_PROP_CAPACITY,
+       POWER_SUPPLY_PROP_CHARGE_FULL,
+       POWER_SUPPLY_PROP_CHARGE_NOW,
+};
+
+int (*gta02_platform_bat_get_property[])(void) = {
+       gta02_bat_get_present,
+       gta02_bat_get_status,
+       gta02_bat_get_voltage,
+       gta02_bat_get_capacity,
+       gta02_bat_get_charge_full,
+       gta02_bat_get_charge_now,
+};
+
+static struct platform_bat_platform_data gta02_platform_bat_pdata = {
+       .name = "battery",
+       .properties = gta02_platform_bat_properties,
+       .num_properties = ARRAY_SIZE(gta02_platform_bat_properties),
+       .get_property = gta02_platform_bat_get_property,
+       .is_present = gta02_bat_get_present,
+};
+
+struct platform_device gta02_platform_bat = {
+       .name = "platform_battery",
+       .id = -1,
+       .dev = {
+               .platform_data = &gta02_platform_bat_pdata,
+       }
+};
+
 /* HDQ */
 
 static void gta02_hdq_gpio_direction_out(void)
@@ -987,6 +1099,7 @@ static struct platform_device *gta02_devices[] __initdata = {
 
 static struct platform_device *gta02_devices_pmu_children[] = {
     &gta02_hdq_device,
+       &gta02_platform_bat,
 };
 
 /*