power: Add support for DA9150 Fuel-Gauge

This adds power supply driver support for the Fuel-Gauge part of
the DA9150 combined Charger and Fuel-Gauge device.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Acked-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

3 files changed, 590 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index f8758d6febf8..8d53f58f20dd 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -204,6 +204,16 @@ config CHARGER_DA9150
 	  This driver can also be built as a module. If so, the module will be
 	  called da9150-charger.
 
+config BATTERY_DA9150
+	tristate "Dialog Semiconductor DA9150 Fuel Gauge support"
+	depends on MFD_DA9150
+	help
+	  Say Y here to enable support for the Fuel-Gauge unit of the DA9150
+	  Integrated Charger & Fuel-Gauge IC
+
+	  This driver can also be built as a module. If so, the module will be
+	  called da9150-fg.
+
 config AXP288_CHARGER
 	tristate "X-Powers AXP288 Charger"
 	depends on MFD_AXP20X && EXTCON_AXP288
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 5752ce818f51..cbdf89d595a3 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_BATTERY_BQ27x00)	+= bq27x00_battery.o
 obj-$(CONFIG_BATTERY_DA9030)	+= da9030_battery.o
 obj-$(CONFIG_BATTERY_DA9052)	+= da9052-battery.o
 obj-$(CONFIG_CHARGER_DA9150)	+= da9150-charger.o
+obj-$(CONFIG_BATTERY_DA9150)	+= da9150-fg.o
 obj-$(CONFIG_BATTERY_MAX17040)	+= max17040_battery.o
 obj-$(CONFIG_BATTERY_MAX17042)	+= max17042_battery.o
 obj-$(CONFIG_BATTERY_Z2)	+= z2_battery.o
diff --git a/drivers/power/da9150-fg.c b/drivers/power/da9150-fg.c
new file mode 100644
index 000000000000..8b8ce978656a
--- /dev/null
+++ b/drivers/power/da9150-fg.c
@@ -0,0 +1,579 @@
+/*
+ * DA9150 Fuel-Gauge Driver
+ *
+ * Copyright (c) 2015 Dialog Semiconductor
+ *
+ * Author: Adam Thomson <Adam.Thomson.Opensource@diasemi.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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/power_supply.h>
+#include <linux/list.h>
+#include <asm/div64.h>
+#include <linux/mfd/da9150/core.h>
+#include <linux/mfd/da9150/registers.h>
+
+/* Core2Wire */
+#define DA9150_QIF_READ		(0x0 << 7)
+#define DA9150_QIF_WRITE	(0x1 << 7)
+#define DA9150_QIF_CODE_MASK	0x7F
+
+#define DA9150_QIF_BYTE_SIZE	8
+#define DA9150_QIF_BYTE_MASK	0xFF
+#define DA9150_QIF_SHORT_SIZE	2
+#define DA9150_QIF_LONG_SIZE	4
+
+/* QIF Codes */
+#define DA9150_QIF_UAVG			6
+#define DA9150_QIF_UAVG_SIZE		DA9150_QIF_LONG_SIZE
+#define DA9150_QIF_IAVG			8
+#define DA9150_QIF_IAVG_SIZE		DA9150_QIF_LONG_SIZE
+#define DA9150_QIF_NTCAVG		12
+#define DA9150_QIF_NTCAVG_SIZE		DA9150_QIF_LONG_SIZE
+#define DA9150_QIF_SHUNT_VAL		36
+#define DA9150_QIF_SHUNT_VAL_SIZE	DA9150_QIF_SHORT_SIZE
+#define DA9150_QIF_SD_GAIN		38
+#define DA9150_QIF_SD_GAIN_SIZE		DA9150_QIF_LONG_SIZE
+#define DA9150_QIF_FCC_MAH		40
+#define DA9150_QIF_FCC_MAH_SIZE		DA9150_QIF_SHORT_SIZE
+#define DA9150_QIF_SOC_PCT		43
+#define DA9150_QIF_SOC_PCT_SIZE		DA9150_QIF_SHORT_SIZE
+#define DA9150_QIF_CHARGE_LIMIT		44
+#define DA9150_QIF_CHARGE_LIMIT_SIZE	DA9150_QIF_SHORT_SIZE
+#define DA9150_QIF_DISCHARGE_LIMIT	45
+#define DA9150_QIF_DISCHARGE_LIMIT_SIZE	DA9150_QIF_SHORT_SIZE
+#define DA9150_QIF_FW_MAIN_VER		118
+#define DA9150_QIF_FW_MAIN_VER_SIZE	DA9150_QIF_SHORT_SIZE
+#define DA9150_QIF_E_FG_STATUS		126
+#define DA9150_QIF_E_FG_STATUS_SIZE	DA9150_QIF_SHORT_SIZE
+#define DA9150_QIF_SYNC			127
+#define DA9150_QIF_SYNC_SIZE		DA9150_QIF_SHORT_SIZE
+#define DA9150_QIF_MAX_CODES		128
+
+/* QIF Sync Timeout */
+#define DA9150_QIF_SYNC_TIMEOUT		1000
+#define DA9150_QIF_SYNC_RETRIES		10
+
+/* QIF E_FG_STATUS */
+#define DA9150_FG_IRQ_LOW_SOC_MASK	(1 << 0)
+#define DA9150_FG_IRQ_HIGH_SOC_MASK	(1 << 1)
+#define DA9150_FG_IRQ_SOC_MASK	\
+	(DA9150_FG_IRQ_LOW_SOC_MASK | DA9150_FG_IRQ_HIGH_SOC_MASK)
+
+/* Private data */
+struct da9150_fg {
+	struct da9150 *da9150;
+	struct device *dev;
+
+	struct mutex io_lock;
+
+	struct power_supply *battery;
+	struct delayed_work work;
+	u32 interval;
+
+	int warn_soc;
+	int crit_soc;
+	int soc;
+};
+
+/* Battery Properties */
+static u32 da9150_fg_read_attr(struct da9150_fg *fg, u8 code, u8 size)
+
+{
+	u8 buf[size];
+	u8 read_addr;
+	u32 res = 0;
+	int i;
+
+	/* Set QIF code (READ mode) */
+	read_addr = (code & DA9150_QIF_CODE_MASK) | DA9150_QIF_READ;
+
+	da9150_read_qif(fg->da9150, read_addr, size, buf);
+	for (i = 0; i < size; ++i)
+		res |= (buf[i] << (i * DA9150_QIF_BYTE_SIZE));
+
+	return res;
+}
+
+static void da9150_fg_write_attr(struct da9150_fg *fg, u8 code, u8 size,
+				 u32 val)
+
+{
+	u8 buf[size];
+	u8 write_addr;
+	int i;
+
+	/* Set QIF code (WRITE mode) */
+	write_addr = (code & DA9150_QIF_CODE_MASK) | DA9150_QIF_WRITE;
+
+	for (i = 0; i < size; ++i) {
+		buf[i] = (val >> (i * DA9150_QIF_BYTE_SIZE)) &
+			 DA9150_QIF_BYTE_MASK;
+	}
+	da9150_write_qif(fg->da9150, write_addr, size, buf);
+}
+
+/* Trigger QIF Sync to update QIF readable data */
+static void da9150_fg_read_sync_start(struct da9150_fg *fg)
+{
+	int i = 0;
+	u32 res = 0;
+
+	mutex_lock(&fg->io_lock);
+
+	/* Check if QIF sync already requested, and write to sync if not */
+	res = da9150_fg_read_attr(fg, DA9150_QIF_SYNC,
+				  DA9150_QIF_SYNC_SIZE);
+	if (res > 0)
+		da9150_fg_write_attr(fg, DA9150_QIF_SYNC,
+				     DA9150_QIF_SYNC_SIZE, 0);
+
+	/* Wait for sync to complete */
+	res = 0;
+	while ((res == 0) && (i++ < DA9150_QIF_SYNC_RETRIES)) {
+		usleep_range(DA9150_QIF_SYNC_TIMEOUT,
+			     DA9150_QIF_SYNC_TIMEOUT * 2);
+		res = da9150_fg_read_attr(fg, DA9150_QIF_SYNC,
+					  DA9150_QIF_SYNC_SIZE);
+	}
+
+	/* Check if sync completed */
+	if (res == 0)
+		dev_err(fg->dev, "Failed to perform QIF read sync!\n");
+}
+
+/*
+ * Should always be called after QIF sync read has been performed, and all
+ * attributes required have been accessed.
+ */
+static inline void da9150_fg_read_sync_end(struct da9150_fg *fg)
+{
+	mutex_unlock(&fg->io_lock);
+}
+
+/* Sync read of single QIF attribute */
+static u32 da9150_fg_read_attr_sync(struct da9150_fg *fg, u8 code, u8 size)
+{
+	u32 val;
+
+	da9150_fg_read_sync_start(fg);
+	val = da9150_fg_read_attr(fg, code, size);
+	da9150_fg_read_sync_end(fg);
+
+	return val;
+}
+
+/* Wait for QIF Sync, write QIF data and wait for ack */
+static void da9150_fg_write_attr_sync(struct da9150_fg *fg, u8 code, u8 size,
+				      u32 val)
+{
+	int i = 0;
+	u32 res = 0, sync_val;
+
+	mutex_lock(&fg->io_lock);
+
+	/* Check if QIF sync already requested */
+	res = da9150_fg_read_attr(fg, DA9150_QIF_SYNC,
+				  DA9150_QIF_SYNC_SIZE);
+
+	/* Wait for an existing sync to complete */
+	while ((res == 0) && (i++ < DA9150_QIF_SYNC_RETRIES)) {
+		usleep_range(DA9150_QIF_SYNC_TIMEOUT,
+			     DA9150_QIF_SYNC_TIMEOUT * 2);
+		res = da9150_fg_read_attr(fg, DA9150_QIF_SYNC,
+					  DA9150_QIF_SYNC_SIZE);
+	}
+
+	if (res == 0) {
+		dev_err(fg->dev, "Timeout waiting for existing QIF sync!\n");
+		mutex_unlock(&fg->io_lock);
+		return;
+	}
+
+	/* Write value for QIF code */
+	da9150_fg_write_attr(fg, code, size, val);
+
+	/* Wait for write acknowledgment */
+	i = 0;
+	sync_val = res;
+	while ((res == sync_val) && (i++ < DA9150_QIF_SYNC_RETRIES)) {
+		usleep_range(DA9150_QIF_SYNC_TIMEOUT,
+			     DA9150_QIF_SYNC_TIMEOUT * 2);
+		res = da9150_fg_read_attr(fg, DA9150_QIF_SYNC,
+					  DA9150_QIF_SYNC_SIZE);
+	}
+
+	mutex_unlock(&fg->io_lock);
+
+	/* Check write was actually successful */
+	if (res != (sync_val + 1))
+		dev_err(fg->dev, "Error performing QIF sync write for code %d\n",
+			code);
+}
+
+/* Power Supply attributes */
+static int da9150_fg_capacity(struct da9150_fg *fg,
+			      union power_supply_propval *val)
+{
+	val->intval = da9150_fg_read_attr_sync(fg, DA9150_QIF_SOC_PCT,
+					       DA9150_QIF_SOC_PCT_SIZE);
+
+	if (val->intval > 100)
+		val->intval = 100;
+
+	return 0;
+}
+
+static int da9150_fg_current_avg(struct da9150_fg *fg,
+				 union power_supply_propval *val)
+{
+	u32 iavg, sd_gain, shunt_val;
+	u64 div, res;
+
+	da9150_fg_read_sync_start(fg);
+	iavg = da9150_fg_read_attr(fg, DA9150_QIF_IAVG,
+				   DA9150_QIF_IAVG_SIZE);
+	shunt_val = da9150_fg_read_attr(fg, DA9150_QIF_SHUNT_VAL,
+					DA9150_QIF_SHUNT_VAL_SIZE);
+	sd_gain = da9150_fg_read_attr(fg, DA9150_QIF_SD_GAIN,
+				      DA9150_QIF_SD_GAIN_SIZE);
+	da9150_fg_read_sync_end(fg);
+
+	div = (u64) (sd_gain * shunt_val * 65536ULL);
+	do_div(div, 1000000);
+	res = (u64) (iavg * 1000000ULL);
+	do_div(res, div);
+
+	val->intval = (int) res;
+
+	return 0;
+}
+
+static int da9150_fg_voltage_avg(struct da9150_fg *fg,
+				 union power_supply_propval *val)
+{
+	u64 res;
+
+	val->intval = da9150_fg_read_attr_sync(fg, DA9150_QIF_UAVG,
+					       DA9150_QIF_UAVG_SIZE);
+
+	res = (u64) (val->intval * 186ULL);
+	do_div(res, 10000);
+	val->intval = (int) res;
+
+	return 0;
+}
+
+static int da9150_fg_charge_full(struct da9150_fg *fg,
+				 union power_supply_propval *val)
+{
+	val->intval = da9150_fg_read_attr_sync(fg, DA9150_QIF_FCC_MAH,
+					       DA9150_QIF_FCC_MAH_SIZE);
+
+	val->intval = val->intval * 1000;
+
+	return 0;
+}
+
+/*
+ * Temperature reading from device is only valid if battery/system provides
+ * valid NTC to associated pin of DA9150 chip.
+ */
+static int da9150_fg_temp(struct da9150_fg *fg,
+			  union power_supply_propval *val)
+{
+	val->intval = da9150_fg_read_attr_sync(fg, DA9150_QIF_NTCAVG,
+					       DA9150_QIF_NTCAVG_SIZE);
+
+	val->intval = (val->intval * 10) / 1048576;
+
+	return 0;
+}
+
+static enum power_supply_property da9150_fg_props[] = {
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_CURRENT_AVG,
+	POWER_SUPPLY_PROP_VOLTAGE_AVG,
+	POWER_SUPPLY_PROP_CHARGE_FULL,
+	POWER_SUPPLY_PROP_TEMP,
+};
+
+static int da9150_fg_get_prop(struct power_supply *psy,
+			      enum power_supply_property psp,
+			      union power_supply_propval *val)
+{
+	struct da9150_fg *fg = dev_get_drvdata(psy->dev.parent);
+	int ret;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CAPACITY:
+		ret = da9150_fg_capacity(fg, val);
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_AVG:
+		ret = da9150_fg_current_avg(fg, val);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
+		ret = da9150_fg_voltage_avg(fg, val);
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL:
+		ret = da9150_fg_charge_full(fg, val);
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		ret = da9150_fg_temp(fg, val);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+/* Repeated SOC check */
+static bool da9150_fg_soc_changed(struct da9150_fg *fg)
+{
+	union power_supply_propval val;
+
+	da9150_fg_capacity(fg, &val);
+	if (val.intval != fg->soc) {
+		fg->soc = val.intval;
+		return true;
+	}
+
+	return false;
+}
+
+static void da9150_fg_work(struct work_struct *work)
+{
+	struct da9150_fg *fg = container_of(work, struct da9150_fg, work.work);
+
+	/* Report if SOC has changed */
+	if (da9150_fg_soc_changed(fg))
+		power_supply_changed(fg->battery);
+
+	schedule_delayed_work(&fg->work, msecs_to_jiffies(fg->interval));
+}
+
+/* SOC level event configuration */
+static void da9150_fg_soc_event_config(struct da9150_fg *fg)
+{
+	int soc;
+
+	soc = da9150_fg_read_attr_sync(fg, DA9150_QIF_SOC_PCT,
+				       DA9150_QIF_SOC_PCT_SIZE);
+
+	if (soc > fg->warn_soc) {
+		/* If SOC > warn level, set discharge warn level event */
+		da9150_fg_write_attr_sync(fg, DA9150_QIF_DISCHARGE_LIMIT,
+					  DA9150_QIF_DISCHARGE_LIMIT_SIZE,
+					  fg->warn_soc + 1);
+	} else if ((soc <= fg->warn_soc) && (soc > fg->crit_soc)) {
+		/*
+		 * If SOC <= warn level, set discharge crit level event,
+		 * and set charge warn level event.
+		 */
+		da9150_fg_write_attr_sync(fg, DA9150_QIF_DISCHARGE_LIMIT,
+					  DA9150_QIF_DISCHARGE_LIMIT_SIZE,
+					  fg->crit_soc + 1);
+
+		da9150_fg_write_attr_sync(fg, DA9150_QIF_CHARGE_LIMIT,
+					  DA9150_QIF_CHARGE_LIMIT_SIZE,
+					  fg->warn_soc);
+	} else if (soc <= fg->crit_soc) {
+		/* If SOC <= crit level, set charge crit level event */
+		da9150_fg_write_attr_sync(fg, DA9150_QIF_CHARGE_LIMIT,
+					  DA9150_QIF_CHARGE_LIMIT_SIZE,
+					  fg->crit_soc);
+	}
+}
+
+static irqreturn_t da9150_fg_irq(int irq, void *data)
+{
+	struct da9150_fg *fg = data;
+	u32 e_fg_status;
+
+	/* Read FG IRQ status info */
+	e_fg_status = da9150_fg_read_attr(fg, DA9150_QIF_E_FG_STATUS,
+					  DA9150_QIF_E_FG_STATUS_SIZE);
+
+	/* Handle warning/critical threhold events */
+	if (e_fg_status & DA9150_FG_IRQ_SOC_MASK)
+		da9150_fg_soc_event_config(fg);
+
+	/* Clear any FG IRQs */
+	da9150_fg_write_attr(fg, DA9150_QIF_E_FG_STATUS,
+			     DA9150_QIF_E_FG_STATUS_SIZE, e_fg_status);
+
+	return IRQ_HANDLED;
+}
+
+static struct da9150_fg_pdata *da9150_fg_dt_pdata(struct device *dev)
+{
+	struct device_node *fg_node = dev->of_node;
+	struct da9150_fg_pdata *pdata;
+
+	pdata = devm_kzalloc(dev, sizeof(struct da9150_fg_pdata), GFP_KERNEL);
+	if (!pdata)
+		return NULL;
+
+	of_property_read_u32(fg_node, "dlg,update-interval",
+			     &pdata->update_interval);
+	of_property_read_u8(fg_node, "dlg,warn-soc-level",
+			    &pdata->warn_soc_lvl);
+	of_property_read_u8(fg_node, "dlg,crit-soc-level",
+			    &pdata->crit_soc_lvl);
+
+	return pdata;
+}
+
+static const struct power_supply_desc fg_desc = {
+	.name		= "da9150-fg",
+	.type		= POWER_SUPPLY_TYPE_BATTERY,
+	.properties	= da9150_fg_props,
+	.num_properties	= ARRAY_SIZE(da9150_fg_props),
+	.get_property	= da9150_fg_get_prop,
+};
+
+static int da9150_fg_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct da9150 *da9150 = dev_get_drvdata(dev->parent);
+	struct da9150_fg_pdata *fg_pdata = dev_get_platdata(dev);
+	struct da9150_fg *fg;
+	int ver, irq, ret = 0;
+
+	fg = devm_kzalloc(dev, sizeof(*fg), GFP_KERNEL);
+	if (fg == NULL)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, fg);
+	fg->da9150 = da9150;
+	fg->dev = dev;
+
+	mutex_init(&fg->io_lock);
+
+	/* Enable QIF */
+	da9150_set_bits(da9150, DA9150_CORE2WIRE_CTRL_A, DA9150_FG_QIF_EN_MASK,
+			DA9150_FG_QIF_EN_MASK);
+
+	fg->battery = devm_power_supply_register(dev, &fg_desc, NULL);
+	if (IS_ERR(fg->battery)) {
+		ret = PTR_ERR(fg->battery);
+		return ret;
+	}
+
+	ver = da9150_fg_read_attr(fg, DA9150_QIF_FW_MAIN_VER,
+				  DA9150_QIF_FW_MAIN_VER_SIZE);
+	dev_info(dev, "Version: 0x%x\n", ver);
+
+	/* Handle DT data if provided */
+	if (dev->of_node) {
+		fg_pdata = da9150_fg_dt_pdata(dev);
+		dev->platform_data = fg_pdata;
+	}
+
+	/* Handle any pdata provided */
+	if (fg_pdata) {
+		fg->interval = fg_pdata->update_interval;
+
+		if (fg_pdata->warn_soc_lvl > 100)
+			dev_warn(dev, "Invalid SOC warning level provided, Ignoring");
+		else
+			fg->warn_soc = fg_pdata->warn_soc_lvl;
+
+		if ((fg_pdata->crit_soc_lvl > 100) ||
+		    (fg_pdata->crit_soc_lvl >= fg_pdata->warn_soc_lvl))
+			dev_warn(dev, "Invalid SOC critical level provided, Ignoring");
+		else
+			fg->crit_soc = fg_pdata->crit_soc_lvl;
+
+
+	}
+
+	/* Configure initial SOC level events */
+	da9150_fg_soc_event_config(fg);
+
+	/*
+	 * If an interval period has been provided then setup repeating
+	 * work for reporting data updates.
+	 */
+	if (fg->interval) {
+		INIT_DELAYED_WORK(&fg->work, da9150_fg_work);
+		schedule_delayed_work(&fg->work,
+				      msecs_to_jiffies(fg->interval));
+	}
+
+	/* Register IRQ */
+	irq = platform_get_irq_byname(pdev, "FG");
+	if (irq < 0) {
+		dev_err(dev, "Failed to get IRQ FG: %d\n", irq);
+		ret = irq;
+		goto irq_fail;
+	}
+
+	ret = devm_request_threaded_irq(dev, irq, NULL, da9150_fg_irq,
+					IRQF_ONESHOT, "FG", fg);
+	if (ret) {
+		dev_err(dev, "Failed to request IRQ %d: %d\n", irq, ret);
+		goto irq_fail;
+	}
+
+	return 0;
+
+irq_fail:
+	if (fg->interval)
+		cancel_delayed_work(&fg->work);
+
+	return ret;
+}
+
+static int da9150_fg_remove(struct platform_device *pdev)
+{
+	struct da9150_fg *fg = platform_get_drvdata(pdev);
+
+	if (fg->interval)
+		cancel_delayed_work(&fg->work);
+
+	return 0;
+}
+
+static int da9150_fg_resume(struct platform_device *pdev)
+{
+	struct da9150_fg *fg = platform_get_drvdata(pdev);
+
+	/*
+	 * Trigger SOC check to happen now so as to indicate any value change
+	 * since last check before suspend.
+	 */
+	if (fg->interval)
+		flush_delayed_work(&fg->work);
+
+	return 0;
+}
+
+static struct platform_driver da9150_fg_driver = {
+	.driver = {
+		.name = "da9150-fuel-gauge",
+	},
+	.probe = da9150_fg_probe,
+	.remove = da9150_fg_remove,
+	.resume = da9150_fg_resume,
+};
+
+module_platform_driver(da9150_fg_driver);
+
+MODULE_DESCRIPTION("Fuel-Gauge Driver for DA9150");
+MODULE_AUTHOR("Adam Thomson <Adam.Thomson.Opensource@diasemi.com>");
+MODULE_LICENSE("GPL");