pmic:fuel-gauge: Support for MAX17042 fuel-gauge

Support for MAX17042 fuel-gauge (FG), which is built into the MAX8997
power management device.
Special file - fg_battery_cell_params.h with cells characteristics
added.

The FG device will work with redesigned PMIC framework.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Stefano Babic <sbabic@denx.de>
diff --git a/drivers/power/fuel_gauge/Makefile b/drivers/power/fuel_gauge/Makefile
new file mode 100644
index 0000000..da15414
--- /dev/null
+++ b/drivers/power/fuel_gauge/Makefile
@@ -0,0 +1,47 @@
+#
+# Copyright (C) 2012 Samsung Electronics
+# Lukasz Majewski <l.majewski@samsung.com>
+#
+# 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 $(TOPDIR)/config.mk
+
+LIB	:= $(obj)libfuel_gauge.o
+
+COBJS-$(CONFIG_POWER_FG_MAX17042) += fg_max17042.o
+
+COBJS	:= $(COBJS-y)
+SRCS	:= $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+
+all:	$(LIB)
+
+$(LIB):	$(obj).depend $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
+
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+########################################################################
diff --git a/drivers/power/fuel_gauge/fg_max17042.c b/drivers/power/fuel_gauge/fg_max17042.c
new file mode 100644
index 0000000..9b7c184
--- /dev/null
+++ b/drivers/power/fuel_gauge/fg_max17042.c
@@ -0,0 +1,250 @@
+/*
+ *  Copyright (C) 2012 Samsung Electronics
+ *  Lukasz Majewski <l.majewski@samsung.com>
+ *
+ * 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 <power/pmic.h>
+#include <power/max17042_fg.h>
+#include <i2c.h>
+#include <power/max8997_pmic.h>
+#include <power/power_chrg.h>
+#include <power/battery.h>
+#include <power/fg_battery_cell_params.h>
+#include <errno.h>
+
+static int fg_write_regs(struct pmic *p, u8 addr, u16 *data, int num)
+{
+	int ret = 0;
+	int i;
+
+	for (i = 0; i < num; i++, addr++)
+		ret |= pmic_reg_write(p, addr, *(data + i));
+
+	return ret;
+}
+
+static int fg_read_regs(struct pmic *p, u8 addr, u16 *data, int num)
+{
+	int ret = 0;
+	int i;
+
+	for (i = 0; i < num; i++, addr++)
+		ret |= pmic_reg_read(p, addr, (u32 *) (data + i));
+
+	return ret;
+}
+
+static int fg_write_and_verify(struct pmic *p, u8 addr, u16 data)
+{
+	unsigned int val = data;
+	int ret = 0;
+
+	ret |= pmic_reg_write(p, addr, val);
+	ret |= pmic_reg_read(p, addr, &val);
+
+	if (ret)
+		return ret;
+
+	if (((u16) val) == data)
+		return 0;
+
+	return -1;
+}
+
+static void por_fuelgauge_init(struct pmic *p)
+{
+	u16 r_data0[16], r_data1[16], r_data2[16];
+	u32 rewrite_count = 5, i = 0;
+	unsigned int val;
+	int ret = 0;
+
+	/* Delay 500 ms */
+	mdelay(500);
+	/* Initilize Configuration */
+	pmic_reg_write(p, MAX17042_CONFIG, 0x2310);
+
+rewrite_model:
+	/* Unlock Model Access */
+	pmic_reg_write(p, MAX17042_MLOCKReg1, MODEL_UNLOCK1);
+	pmic_reg_write(p, MAX17042_MLOCKReg2, MODEL_UNLOCK2);
+
+	/* Write/Read/Verify the Custom Model */
+	ret |= fg_write_regs(p, MAX17042_MODEL1, cell_character0,
+			     ARRAY_SIZE(cell_character0));
+	ret |= fg_write_regs(p, MAX17042_MODEL2, cell_character1,
+			     ARRAY_SIZE(cell_character1));
+	ret |= fg_write_regs(p, MAX17042_MODEL3, cell_character2,
+			     ARRAY_SIZE(cell_character2));
+
+	if (ret) {
+		printf("%s: Cell parameters write failed!\n", __func__);
+		return;
+	}
+
+	ret |= fg_read_regs(p, MAX17042_MODEL1, r_data0, ARRAY_SIZE(r_data0));
+	ret |= fg_read_regs(p, MAX17042_MODEL2, r_data1, ARRAY_SIZE(r_data1));
+	ret |= fg_read_regs(p, MAX17042_MODEL3, r_data2, ARRAY_SIZE(r_data2));
+
+	if (ret)
+		printf("%s: Cell parameters read failed!\n", __func__);
+
+	for (i = 0; i < 16; i++) {
+		if ((cell_character0[i] != r_data0[i])
+		    || (cell_character1[i] != r_data1[i])
+		    || (cell_character2[i] != r_data2[i]))
+			goto rewrite_model;
+		}
+
+	/* Lock model access */
+	pmic_reg_write(p, MAX17042_MLOCKReg1, MODEL_LOCK1);
+	pmic_reg_write(p, MAX17042_MLOCKReg2, MODEL_LOCK2);
+
+	/* Verify the model access is locked */
+	ret |= fg_read_regs(p, MAX17042_MODEL1, r_data0, ARRAY_SIZE(r_data0));
+	ret |= fg_read_regs(p, MAX17042_MODEL2, r_data1, ARRAY_SIZE(r_data1));
+	ret |= fg_read_regs(p, MAX17042_MODEL3, r_data2, ARRAY_SIZE(r_data2));
+
+	if (ret) {
+		printf("%s: Cell parameters read failed!\n", __func__);
+		return;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(r_data0); i++) {
+		/* Check if model locked */
+		if (r_data0[i] || r_data1[i] || r_data2[i]) {
+			/* Rewrite model data - prevent from endless loop */
+			if (rewrite_count--) {
+				puts("FG - Lock model access failed!\n");
+				goto rewrite_model;
+			}
+		}
+	}
+
+	/* Write Custom Parameters */
+	fg_write_and_verify(p, MAX17042_RCOMP0, RCOMP0);
+	fg_write_and_verify(p, MAX17042_TEMPCO, TempCo);
+
+	/* Delay at least 350mS */
+	mdelay(350);
+
+	/* Initialization Complete */
+	pmic_reg_read(p, MAX17042_STATUS, &val);
+	/* Write and Verify Status with POR bit Cleared */
+	fg_write_and_verify(p, MAX17042_STATUS, val & ~MAX17042_POR);
+
+	/* Delay at least 350 ms */
+	mdelay(350);
+}
+
+static int power_update_battery(struct pmic *p, struct pmic *bat)
+{
+	struct power_battery *pb = bat->pbat;
+	unsigned int val;
+	int ret = 0;
+
+	if (pmic_probe(p)) {
+		puts("Can't find max17042 fuel gauge\n");
+		return -1;
+	}
+
+	ret |= pmic_reg_read(p, MAX17042_VFSOC, &val);
+	pb->bat->state_of_chrg = (val >> 8);
+
+	pmic_reg_read(p, MAX17042_VCELL, &val);
+	debug("vfsoc: 0x%x\n", val);
+	pb->bat->voltage_uV = ((val & 0xFFUL) >> 3) + ((val & 0xFF00) >> 3);
+	pb->bat->voltage_uV = (pb->bat->voltage_uV * 625);
+
+	pmic_reg_read(p, 0x05, &val);
+	pb->bat->capacity = val >> 2;
+
+	return ret;
+}
+
+static int power_check_battery(struct pmic *p, struct pmic *bat)
+{
+	struct power_battery *pb = bat->pbat;
+	unsigned int val;
+	int ret = 0;
+
+	if (pmic_probe(p)) {
+		puts("Can't find max17042 fuel gauge\n");
+		return -1;
+	}
+
+	ret |= pmic_reg_read(p, MAX17042_STATUS, &val);
+	debug("fg status: 0x%x\n", val);
+
+	if (val == MAX17042_POR)
+		por_fuelgauge_init(p);
+
+	ret |= pmic_reg_read(p, MAX17042_VERSION, &val);
+	pb->bat->version = val;
+
+	power_update_battery(p, bat);
+	debug("fg ver: 0x%x\n", pb->bat->version);
+	printf("BAT: state_of_charge(SOC):%d%%\n",
+	       pb->bat->state_of_chrg);
+
+	printf("     voltage: %d.%6.6d [V] (expected to be %d [mAh])\n",
+	       pb->bat->voltage_uV / 1000000,
+	       pb->bat->voltage_uV % 1000000,
+	       pb->bat->capacity);
+
+	if (pb->bat->voltage_uV > 3850000)
+		pb->bat->state = EXT_SOURCE;
+	else if (pb->bat->voltage_uV < 3600000 || pb->bat->state_of_chrg < 5)
+		pb->bat->state = CHARGE;
+	else
+		pb->bat->state = NORMAL;
+
+	return ret;
+}
+
+static struct power_fg power_fg_ops = {
+	.fg_battery_check = power_check_battery,
+	.fg_battery_update = power_update_battery,
+};
+
+int power_fg_init(unsigned char bus)
+{
+	static const char name[] = "MAX17042_FG";
+	struct pmic *p = pmic_alloc();
+
+	if (!p) {
+		printf("%s: POWER allocation error!\n", __func__);
+		return -ENOMEM;
+	}
+
+	debug("Board Fuel Gauge init\n");
+
+	p->name = name;
+	p->interface = PMIC_I2C;
+	p->number_of_regs = FG_NUM_OF_REGS;
+	p->hw.i2c.addr = MAX17042_I2C_ADDR;
+	p->hw.i2c.tx_num = 2;
+	p->sensor_byte_order = PMIC_SENSOR_BYTE_ORDER_BIG;
+	p->bus = bus;
+
+	p->fg = &power_fg_ops;
+	return 0;
+}