ARMV7: OMAP4: twl6030 add battery charging support

Add battery charging support twl6030 driver.
Add support for battery voltage and current measurements.
Add command to get battery status and start/stop battery charging from USB.

Signed-off-by: Balaji T K <balajitk@ti.com>
Tested-by: Steve Sakoman <steve.sakoman@linaro.org>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

board/ti/sdp4430/Makefile

@@ -25,7 +25,7 @@ include $(TOPDIR)/config.mk
 
 LIB	= $(obj)lib$(BOARD).o
 
-COBJS	:= sdp.o
+COBJS	:= sdp.o cmd_bat.o
 
 SRCS	:= $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS))

board/ti/sdp4430/cmd_bat.c

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <command.h>
+
+#ifdef CONFIG_CMD_BAT
+#include <twl6030.h>
+
+int do_vbat(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	if (argc == 2) {
+		if (strncmp(argv[1], "startcharge", 12) == 0)
+			twl6030_start_usb_charging();
+		else if (strncmp(argv[1], "stopcharge", 11) == 0)
+			twl6030_stop_usb_charging();
+		else if (strncmp(argv[1], "status", 7) == 0) {
+			twl6030_get_battery_voltage();
+			twl6030_get_battery_current();
+		} else {
+			goto bat_cmd_usage;
+		}
+	} else {
+		goto bat_cmd_usage;
+	}
+	return 0;
+
+bat_cmd_usage:
+	return cmd_usage(cmdtp);
+}
+
+U_BOOT_CMD(
+	bat, 2, 1, do_vbat,
+	"battery charging, voltage/current measurements",
+	"status - display battery voltage and current\n"
+	"bat startcharge - start charging via USB\n"
+	"bat stopcharge - stop charging\n"
+);
+#endif /* CONFIG_BAT_CMD */

board/ti/sdp4430/sdp.c

@@ -23,6 +23,7 @@
  * MA 02111-1307 USA
  */
 #include <common.h>
+#include <twl6030.h>
 #include <asm/arch/sys_proto.h>
 #include <asm/arch/mmc_host_def.h>
 
@@ -63,6 +64,9 @@ int board_eth_init(bd_t *bis)
  */
 int misc_init_r(void)
 {
+#ifdef CONFIG_TWL6030_POWER
+	twl6030_init_battery_charging();
+#endif
 	return 0;
 }
 

drivers/power/twl6030.c

@@ -36,6 +36,54 @@ static inline int twl6030_i2c_read_u8(u8 chip_no, u8 *val, u8 reg)
 	return i2c_read(chip_no, reg, 1, val, 1);
 }
 
+static int twl6030_gpadc_read_channel(u8 channel_no)
+{
+	u8 lsb = 0;
+	u8 msb = 0;
+	int ret = 0;
+
+	ret = twl6030_i2c_read_u8(TWL6030_CHIP_ADC, &lsb,
+				GPCH0_LSB + channel_no * 2);
+	if (ret)
+		return ret;
+
+	ret = twl6030_i2c_read_u8(TWL6030_CHIP_ADC, &msb,
+				GPCH0_MSB + channel_no * 2);
+	if (ret)
+		return ret;
+
+	return (msb << 8) | lsb;
+}
+
+static int twl6030_gpadc_sw2_trigger(void)
+{
+	u8 val;
+	int ret = 0;
+
+	ret = twl6030_i2c_write_u8(TWL6030_CHIP_ADC, CTRL_P2_SP2, CTRL_P2);
+	if (ret)
+		return ret;
+
+	/* Waiting until the SW1 conversion ends*/
+	val =  CTRL_P2_BUSY;
+
+	while (!((val & CTRL_P2_EOCP2) && (!(val & CTRL_P2_BUSY)))) {
+		ret = twl6030_i2c_read_u8(TWL6030_CHIP_ADC, &val, CTRL_P2);
+		if (ret)
+			return ret;
+		udelay(1000);
+	}
+
+	return 0;
+}
+
+void twl6030_stop_usb_charging(void)
+{
+	twl6030_i2c_write_u8(TWL6030_CHIP_CHARGER, 0, CONTROLLER_CTRL1);
+
+	return;
+}
+
 void twl6030_start_usb_charging(void)
 {
 	twl6030_i2c_write_u8(TWL6030_CHIP_CHARGER, CHARGERUSB_VICHRG_1500,
@@ -48,17 +96,89 @@ void twl6030_start_usb_charging(void)
 							CHARGERUSB_INT_MASK);
 	twl6030_i2c_write_u8(TWL6030_CHIP_CHARGER, CHARGERUSB_VOREG_4P0,
 							CHARGERUSB_VOREG);
-	twl6030_i2c_write_u8(TWL6030_CHIP_CHARGER, CHARGERUSB_CTRL2_VITERM_100,
+	twl6030_i2c_write_u8(TWL6030_CHIP_CHARGER, CHARGERUSB_CTRL2_VITERM_400,
 							CHARGERUSB_CTRL2);
+	twl6030_i2c_write_u8(TWL6030_CHIP_CHARGER, TERM, CHARGERUSB_CTRL1);
 	/* Enable USB charging */
 	twl6030_i2c_write_u8(TWL6030_CHIP_CHARGER, CONTROLLER_CTRL1_EN_CHARGER,
 							CONTROLLER_CTRL1);
 	return;
 }
 
+int twl6030_get_battery_current(void)
+{
+	int battery_current = 0;
+	u8 msb = 0;
+	u8 lsb = 0;
+
+	twl6030_i2c_read_u8(TWL6030_CHIP_CHARGER, &msb, FG_REG_11);
+	twl6030_i2c_read_u8(TWL6030_CHIP_CHARGER, &lsb, FG_REG_10);
+	battery_current = ((msb << 8) | lsb);
+
+	/* convert 10 bit signed number to 16 bit signed number */
+	if (battery_current >= 0x2000)
+		battery_current = (battery_current - 0x4000);
+
+	battery_current = battery_current * 3000 / 4096;
+	printf("Battery Current: %d mA\n", battery_current);
+
+	return battery_current;
+}
+
+int twl6030_get_battery_voltage(void)
+{
+	int battery_volt = 0;
+	int ret = 0;
+
+	/* Start GPADC SW conversion */
+	ret = twl6030_gpadc_sw2_trigger();
+	if (ret) {
+		printf("Failed to convert battery voltage\n");
+		return ret;
+	}
+
+	/* measure Vbat voltage */
+	battery_volt = twl6030_gpadc_read_channel(7);
+	if (battery_volt < 0) {
+		printf("Failed to read battery voltage\n");
+		return ret;
+	}
+	battery_volt = (battery_volt * 25 * 1000) >> (10 + 2);
+	printf("Battery Voltage: %d mV\n", battery_volt);
+
+	return battery_volt;
+}
+
 void twl6030_init_battery_charging(void)
 {
-	twl6030_start_usb_charging();
+	u8 stat1 = 0;
+	int battery_volt = 0;
+	int ret = 0;
+
+	/* Enable VBAT measurement */
+	twl6030_i2c_write_u8(TWL6030_CHIP_PM, VBAT_MEAS, MISC1);
+
+	/* Enable GPADC module */
+	ret = twl6030_i2c_write_u8(TWL6030_CHIP_CHARGER, FGS | GPADCS, TOGGLE1);
+	if (ret) {
+		printf("Failed to enable GPADC\n");
+		return;
+	}
+
+	battery_volt = twl6030_get_battery_voltage();
+	if (battery_volt < 0)
+		return;
+
+	if (battery_volt < 3000)
+		printf("Main battery voltage too low!\n");
+
+	/* Check for the presence of USB charger */
+	twl6030_i2c_read_u8(TWL6030_CHIP_CHARGER, &stat1, CONTROLLER_STAT1);
+
+	/* check for battery presence indirectly via Fuel gauge */
+	if ((stat1 & VBUS_DET) && (battery_volt < 3300))
+		twl6030_start_usb_charging();
+
 	return;
 }
 

include/configs/omap4_sdp4430.h

@@ -102,6 +102,7 @@
 
 /* TWL6030 */
 #define CONFIG_TWL6030_POWER		1
+#define CONFIG_CMD_BAT			1
 
 /* MMC */
 #define CONFIG_GENERIC_MMC		1

include/twl6030.h

@@ -32,6 +32,18 @@
 #define TWL6030_CHIP_CHARGER	0x49
 #define TWL6030_CHIP_PWM	0x49
 
+/* Slave Address 0x48 */
+#define VUSB_CFG_STATE		0xA2
+
+#define MISC1			0xE4
+#define VAC_MEAS		(1 << 2)
+#define VBAT_MEAS		(1 << 1)
+#define BB_MEAS			(1 << 0)
+
+#define MISC2			0xE5
+
+/* Slave Address 0x49 */
+
 /* Battery CHARGER REGISTERS */
 #define CONTROLLER_INT_MASK	0xE0
 #define CONTROLLER_CTRL1	0xE1
@@ -76,16 +88,45 @@
 #define CHARGERUSB_VOREG_4P0		0x19
 #define CHARGERUSB_VOREG_4P2		0x23
 #define CHARGERUSB_VOREG_4P76		0x3F
+/* CHARGERUSB_CTRL1 */
+#define SUSPEND_BOOT		(1 << 7)
+#define OPA_MODE		(1 << 6)
+#define HZ_MODE			(1 << 5)
+#define TERM			(1 << 4)
 /* CHARGERUSB_CTRL2 */
 #define CHARGERUSB_CTRL2_VITERM_50	(0 << 5)
 #define CHARGERUSB_CTRL2_VITERM_100	(1 << 5)
 #define CHARGERUSB_CTRL2_VITERM_150	(2 << 5)
+#define CHARGERUSB_CTRL2_VITERM_400	(7 << 5)
 /* CONTROLLER_CTRL1 */
 #define CONTROLLER_CTRL1_EN_CHARGER	(1 << 4)
 #define CONTROLLER_CTRL1_SEL_CHARGER	(1 << 3)
+/* CONTROLLER_STAT1 */
+#define CHRG_EXTCHRG_STATZ	(1 << 7)
+#define CHRG_DET_N		(1 << 5)
+#define VAC_DET			(1 << 3)
+#define VBUS_DET		(1 << 2)
 
-#define VUSB_CFG_STATE		0xA2
-#define MISC2			0xE5
+#define FG_REG_10	0xCA
+#define FG_REG_11	0xCB
+
+#define TOGGLE1		0x90
+#define FGS		(1 << 5)
+#define FGR		(1 << 4)
+#define GPADCS		(1 << 1)
+#define GPADCR		(1 << 0)
+
+#define CTRL_P2		0x34
+#define CTRL_P2_SP2	(1 << 2)
+#define CTRL_P2_EOCP2	(1 << 1)
+#define CTRL_P2_BUSY	(1 << 0)
+
+#define GPCH0_LSB	0x57
+#define GPCH0_MSB	0x58
 
 void twl6030_init_battery_charging(void);
 void twl6030_usb_device_settings(void);
+void twl6030_start_usb_charging(void);
+void twl6030_stop_usb_charging(void);
+int twl6030_get_battery_voltage(void);
+int twl6030_get_battery_current(void);