Message-Id: <1456212425-5937-3-git-send-email-enric.balletbo@collabora.com>
Date:	Tue, 23 Feb 2016 08:27:05 +0100
From:	Enric Balletbo i Serra <enric.balletbo@...labora.com>
To:	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org, Rob Herring <robh+dt@...nel.org>,
	Sebastian Reichel <sre@...nel.org>
Cc:	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Dmitry Eremin-Solenikov <dbaryshkov@...il.com>,
	David Woodhouse <dwmw2@...radead.org>,
	Sjoerd Simons <sjoerd.simons@...labora.co.uk>,
	Martyn Welch <martyn.welch@...labora.com>
Subject: [PATCH v3 2/2] power: ucs1002: Add support for Programmable USB Port Power Controller

The UCS1002-2 provides a USB port power switch for precise control of up
to 2.5 amperes continuous current with over-current limit (OCL), dynamic
thermal management, latch or auto-recovery (low test current) fault
handling, selectable active low or high enable, under- and over-voltage
lockout, back-drive protection, and back-voltage protection.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@...labora.com>
---
Changes since v2:
 - Rename microchip,current-limit to microchip,limit-microamps (Rob Herring)
Changes since v1:
 - Fix ERROR: info -> pdata is NULL but dereferenced (kbuild)
 - Change CONFIG_POWER_UCS1002 to CONFIG_UCS1002_POWER, seems more standard
   (Enric Balletbo)

 drivers/power/Kconfig         |    7 +
 drivers/power/Makefile        |    1 +
 drivers/power/ucs1002_power.c | 1004 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1012 insertions(+)
 create mode 100644 drivers/power/ucs1002_power.c

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 1ddd13c..534e9db 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -502,6 +502,13 @@ config AXP20X_POWER
 	  This driver provides support for the power supply features of
 	  AXP20x PMIC.
 
+config UCS1002_POWER
+	tristate "UCS1002-2 power supply driver"
+	select REGMAP_I2C
+	help
+	  This driver provices support for UCS1002-2 Programmable USB Port
+	  Power Controller.
+
 endif # POWER_SUPPLY
 
 source "drivers/power/reset/Kconfig"
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 0e4eab5..936d2e1 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -73,3 +73,4 @@ obj-$(CONFIG_CHARGER_TPS65217)	+= tps65217_charger.o
 obj-$(CONFIG_POWER_RESET)	+= reset/
 obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o
 obj-$(CONFIG_AXP288_CHARGER)	+= axp288_charger.o
+obj-$(CONFIG_UCS1002_POWER)	+= ucs1002_power.o
diff --git a/drivers/power/ucs1002_power.c b/drivers/power/ucs1002_power.c
new file mode 100644
index 0000000..4f0e4ff
--- /dev/null
+++ b/drivers/power/ucs1002_power.c
@@ -0,0 +1,1004 @@
+/*
+ * Driver for UCS1002 Programmable USB Port Power Controller
+ *
+ * Copyright (C) 2016 Zodiac Inflight Innovations
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <linux/freezer.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+
+#define POLL_INTERVAL		(HZ * 2)
+
+/* UCS1002 Registers */
+#define UCS1002_REG_CURRENT_MEASUREMENT	0x00
+
+/*
+ * The Total Accumulated Charge registers store the total accumulated charge
+ * delivered from the VS source to a portable device. The total value is
+ * calculated using four registers, from 01h to 04h. The bit weighting of
+ * the registers is given in mA/hrs.
+ */
+#define UCS1002_REG_TOTAL_ACC_CHARGE	0x01
+
+/* Other Status Register */
+#define UCS1020_REG_OTHER_STATUS	0x0f
+#  define F_ALERT_PIN			BIT(5)
+#  define F_ADET_PIN			BIT(4)
+#  define F_CHG_ACT			BIT(3)
+#  define F_EM_ACT			BIT(2)
+#  define F_EM_STEP_MASK		0x03
+
+/* Interrupt Status */
+#define UCS1002_REG_INTERRUPT_STATUS	0x10
+#  define F_DISCHARGE_ERR		BIT(6)
+#  define F_RESET			BIT(5)
+#  define F_MIN_KEEP_OUT		BIT(4)
+#  define F_TSD				BIT(3)
+#  define F_OVER_VOLT			BIT(2)
+#  define F_BACK_VOLT			BIT(1)
+#  define F_OVER_ILIM			BIT(0)
+
+/* Pin Status Register */
+#define UCS1002_REG_PIN_STATUS		0x14
+#  define UCS1002_PWR_STATE_MASK	0x03
+#  define F_PWR_EN_PIN			BIT(6)
+#  define F_M2_PIN			BIT(5)
+#  define F_M1_PIN			BIT(4)
+#  define F_EM_EN_PIN			BIT(3)
+#  define F_SEL_PIN			BIT(2)
+#  define F_ACTIVE_MODE_MASK		0x38
+#  define F_ACTIVE_MODE_SHIFT		3
+
+/* General Configuration Register */
+#define UCS1002_REG_GENERAL_CFG	0x15
+#  define F_ALERT_MASK			BIT(6)
+#  define F_ALERT_LINK			BIT(5)
+#  define F_DISCHARGE			BIT(4)
+#  define F_RATION_EN			BIT(3)
+#  define F_RATION_RST			BIT(2)
+#  define F_RATION_BEH_MASK		0x03
+#  define F_RATION_BEH_REPORT		0x00
+#  define F_RATION_BEH_REPORT_DISCON	0x01
+#  define F_RATION_BEH_DISCON_SLEEP	0x02
+#  define F_RATION_BEH_IGNORE		0x03
+
+/* Emulation Configuration Register */
+#define UCS1002_REG_EMU_CFG		0x16
+
+/* Switch Configuration Register */
+#define UCS1002_REG_SWITCH_CFG		0x17
+#  define F_PIN_IGNORE			BIT(7)
+#  define F_EM_EN_SET			BIT(5)
+#  define F_M2_SET			BIT(4)
+#  define F_M1_SET			BIT(3)
+#  define F_S0_SET			BIT(2)
+#  define F_PWR_EN_SET			BIT(1)
+#  define F_LATCH_SET			BIT(0)
+#  define V_SET_ACTIVE_MODE_MASK	0x38
+#  define V_SET_ACTIVE_MODE_PASSTHROUGH	F_M2_SET
+#  define V_SET_ACTIVE_MODE_DEDICATED	F_EM_EN_SET
+#  define V_SET_ACTIVE_MODE_BC12_DCP	(F_M2_SET | F_EM_EN_SET)
+#  define V_SET_ACTIVE_MODE_BC12_SDP	F_M1_SET
+#  define V_SET_ACTIVE_MODE_BC12_CDP	(F_M1_SET | F_M2_SET | F_EM_EN_SET)
+
+/* Current Limit Register */
+#define UCS1002_REG_ILIMIT		0x19
+#  define UCS1002_ILIM_SW_MASK		0x07
+
+/* High-speed Switch Configuration Register */
+#define UCS1002_REG_HS_SWITCH_CFG	0x25
+
+/* Custom Emulation Configuration Register */
+#define UCS1002_REG_CUSTOM_EMU_CFG_BASE	0x40
+#define V_CUSTOM_EMU_CFG_NREGS		12
+
+/* Custom Current Limiting Behavior Config */
+#define UCS1002_REG_CUSTOM_ILIMIT_CFG	0x51
+
+/* Product ID */
+#define UCS1002_REG_PRODUCT_ID		0xfd
+#  define UCS1002_PRODUCT_ID		0x4e
+
+/* Manufacture name */
+#define UCS1002_MANUFACTURER		"SMSC"
+
+/* Number of registers to set a custom profile */
+#define UCS1002_PROFILE_NREGS		17
+
+struct ucs1002_platform_data {
+	struct gpio_desc *gpiod_em;
+	struct gpio_desc *gpiod_m1;
+	struct gpio_desc *gpiod_m2;
+	struct gpio_desc *gpiod_pwr;
+};
+
+struct ucs1002_info {
+	struct power_supply *charger;
+	struct i2c_client *client;
+	struct regmap *regmap;
+	struct ucs1002_platform_data *pdata;
+	struct task_struct *poll_task;
+
+	bool curr_alarm;
+	bool enabled;
+	bool present;
+	/* Interrupts */
+	int irq_a_det;
+	int irq_alert;
+};
+
+static const struct regmap_config ucs1002_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static enum power_supply_property ucs1002_props[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_CURRENT_MAX,
+	POWER_SUPPLY_PROP_PRESENT, /* the presence of PED */
+	POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+/*
+ * Iterate through each element of the 'map' array until an element whose value
+ * is equal to 'value' is found. Return the index of the respective element or
+ * -EINVAL if no such element is found.
+ */
+static int ucs1002_find_idx(int value, const int *map, int map_size)
+{
+	int idx;
+
+	for (idx = 0; idx < map_size; idx++)
+		if (value == map[idx])
+			return idx;
+
+	return -EINVAL;
+}
+
+static int ucs1002_power_enable(struct ucs1002_info *info, bool enable)
+{
+	int ret, regval;
+	unsigned int val;
+
+	/* Read the polarity setting determined by the SEL pin */
+	ret = regmap_read(info->regmap, UCS1002_REG_PIN_STATUS, &regval);
+	if (ret < 0)
+		return ret;
+
+	if (regval & F_SEL_PIN)
+		val = enable ? F_PWR_EN_SET : 0;
+	else
+		val = enable ? 0 : F_PWR_EN_SET;
+
+	if (info->pdata) {
+		gpiod_set_value_cansleep(info->pdata->gpiod_pwr, val ? 0 : 1);
+	} else {
+		ret = regmap_update_bits(info->regmap, UCS1002_REG_SWITCH_CFG,
+					 F_PWR_EN_SET, val);
+		if (ret < 0)
+			return ret;
+	}
+
+	info->enabled = enable;
+
+	return 0;
+}
+
+static int ucs1002_get_online(struct ucs1002_info *info,
+			      union power_supply_propval *val)
+{
+	int ret, regval;
+
+	ret = regmap_read(info->regmap, UCS1020_REG_OTHER_STATUS, &regval);
+	if (ret < 0)
+		return -EINVAL;
+
+	val->intval = (regval & F_CHG_ACT) ? 1 : 0;
+
+	return 0;
+}
+
+/*
+ * To fit within 32 bits some values are rounded (uA/h)
+ *
+ * For Total Accumulated Charge Middle Low Byte register, addr 03h, byte 2
+ *
+ *   B0: 0.01084 mA/h rounded to 11 uA/h
+ *   B1: 0.02169 mA/h rounded to 22 uA/h
+ *   B2: 0.04340 mA/h rounded to 43 uA/h
+ *   B3: 0.08676 mA/h rounded to 87 uA/h
+ *   B4: 0.17350 mA/h rounded to 173 uÁ/h
+ *
+ * For Total Accumulated Charge Low Byte register, addr 04h, byte 3
+ *
+ *   B6: 0.00271 mA/h rounded to 3 uA/h
+ *   B7: 0.005422 mA/h rounded to 5 uA/h
+ */
+static const u32 ucs1002_charge_byte_values[4][8] = {
+	[0] = {
+		710700, 1421000, 2843000, 5685000, 11371000, 22742000,
+		45484000, 90968000
+	      },
+	[1] = {
+		2776, 5552, 11105, 22210, 44420, 88840, 177700, 355400
+	      },
+	[2] = {
+		11, 22, 43, 87, 173, 347, 694, 1388
+	      },
+	[3] = {
+		0, 0, 0, 0, 0, 0, 3, 5
+	      }
+};
+
+static int ucs1002_get_charge(struct ucs1002_info *info,
+			      union power_supply_propval *val)
+{
+	int i, j, ret, regval;
+	unsigned int total = 0;
+
+	ret = regmap_read(info->regmap, UCS1002_REG_GENERAL_CFG, &regval);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < 4; i++) {
+		ret = regmap_read(info->regmap,
+				  UCS1002_REG_TOTAL_ACC_CHARGE + i,
+				  &regval);
+		if (ret < 0)
+			return -EINVAL;
+
+		for (j = 0; j < 8; j++)
+			if (regval & BIT(j))
+				total += ucs1002_charge_byte_values[i][j];
+	}
+
+	val->intval = total;
+
+	return 0;
+}
+
+/*
+ * The Current Measurement register stores the measured current value
+ * delivered to the portable device. The range is from 9.76 mA to 2.5 A.
+ * Following values are in uA.
+ */
+static const u32 ucs1002_current_measurement_values[] = {
+	9760, 19500, 39000, 78100, 156200, 312300, 624600,
+	1249300
+};
+
+static int ucs1002_get_current(struct ucs1002_info *info,
+			       union power_supply_propval *val)
+{
+	int n, ret, regval;
+	unsigned int total = 0;
+
+	ret = regmap_read(info->regmap, UCS1002_REG_CURRENT_MEASUREMENT,
+			  &regval);
+	if (ret < 0)
+		return -EINVAL;
+
+	for (n = 0; n < ARRAY_SIZE(ucs1002_current_measurement_values); n++)
+		if (regval & BIT(n))
+			total += ucs1002_current_measurement_values[n];
+
+	val->intval = total;
+
+	return 0;
+}
+
+/*
+ * The Current Limit register stores the maximum current used by the port
+ * switch. The range is from 500mA to 2.5 A. Following values are in uA.
+ */
+static const u32 ucs1002_current_limit_values[] = {
+	500000, 900000, 1000000, 1200000, 1500000, 1800000, 2000000, 2500000
+};
+
+static int ucs1002_get_max_current(struct ucs1002_info *info,
+				   union power_supply_propval *val)
+{
+	int ret, regval;
+
+	ret = regmap_read(info->regmap, UCS1002_REG_ILIMIT, &regval);
+	if (ret < 0)
+		return ret;
+
+	regval &= UCS1002_ILIM_SW_MASK;
+	val->intval = ucs1002_current_limit_values[regval];
+
+	return 0;
+}
+
+static int ucs1002_set_max_current(struct ucs1002_info *info, u32 val)
+{
+	int ret, idx;
+
+	idx = ucs1002_find_idx(val, ucs1002_current_limit_values,
+			       ARRAY_SIZE(ucs1002_current_limit_values));
+	if (idx < 0) {
+		dev_err(&info->client->dev,
+			"%d is an invalid max current value\n", val);
+		return -EINVAL;
+	}
+
+	ret = regmap_write(info->regmap, UCS1002_REG_ILIMIT, idx);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int ucs1002_get_property(struct power_supply *psy,
+				enum power_supply_property psp,
+				union power_supply_propval *val)
+{
+	struct ucs1002_info *info = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		return ucs1002_get_online(info, val);
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+		return ucs1002_get_charge(info, val);
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		return ucs1002_get_current(info, val);
+	case POWER_SUPPLY_PROP_CURRENT_MAX:
+		return ucs1002_get_max_current(info, val);
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = info->present ? 1 : 0;
+		return 0;
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		val->strval = UCS1002_MANUFACTURER;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ucs1002_set_property(struct power_supply *psy,
+				enum power_supply_property psp,
+				const union power_supply_propval *val)
+{
+	struct ucs1002_info *info = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CURRENT_MAX:
+		return ucs1002_set_max_current(info, val->intval);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ucs1002_property_is_writeable(struct power_supply *psy,
+					 enum power_supply_property psp)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CURRENT_MAX:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct power_supply_desc ucs1002_charger_desc = {
+	.name			= "ucs1002",
+	.type			= POWER_SUPPLY_TYPE_MAINS,
+	.get_property		= ucs1002_get_property,
+	.set_property		= ucs1002_set_property,
+	.property_is_writeable	= ucs1002_property_is_writeable,
+	.properties		= ucs1002_props,
+	.num_properties		= ARRAY_SIZE(ucs1002_props),
+};
+
+static ssize_t ucs1002_sysfs_show_curr_alarm(struct device *dev,
+					     struct device_attribute *attr,
+					     char *buf)
+{
+	struct power_supply *psy = dev_get_drvdata(dev);
+	struct ucs1002_info *info = power_supply_get_drvdata(psy);
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n", info->curr_alarm);
+}
+
+static ssize_t ucs1002_sysfs_show_active_mode(struct device *dev,
+					      struct device_attribute *attr,
+					      char *buf)
+{
+	int ret, regval;
+	struct power_supply *psy = dev_get_drvdata(dev);
+	struct ucs1002_info *info = power_supply_get_drvdata(psy);
+
+	ret = regmap_read(info->regmap, UCS1002_REG_PIN_STATUS, &regval);
+	if (ret < 0)
+		return -EINVAL;
+
+	regval &= F_ACTIVE_MODE_MASK;
+	regval = regval >> F_ACTIVE_MODE_SHIFT;
+
+	switch (regval) {
+	/* Dedicated Charger Emulation Cycle */
+	case 1:
+	case 3:
+		return scnprintf(buf, PAGE_SIZE, "%s\n", "dedicated");
+	/* Data Pass-through */
+	case 4:
+	case 6:
+		return scnprintf(buf, PAGE_SIZE, "%s\n", "pass-through");
+	/* BC1.2 SDP */
+	case 2:
+		return scnprintf(buf, PAGE_SIZE, "%s\n", "BC1.2-SDP");
+	/* BC1.2 DCP */
+	case 5:
+		return scnprintf(buf, PAGE_SIZE, "%s\n", "BC1.2-DCP");
+	/* BC1.2 CDP */
+	case 7:
+		return scnprintf(buf, PAGE_SIZE, "%s\n", "BC1.2-CDP");
+	default:
+		return scnprintf(buf, PAGE_SIZE, "%s\n", "unknown");
+	};
+}
+
+static ssize_t ucs1002_sysfs_set_active_mode(struct device *dev,
+					     struct device_attribute *attr,
+					     const char *buf, size_t count)
+{
+	struct power_supply *psy = dev_get_drvdata(dev);
+	struct ucs1002_info *info = power_supply_get_drvdata(psy);
+	int mode, ret = 0;
+
+	if (strncmp(buf, "dedicated", 9) == 0)
+		mode = V_SET_ACTIVE_MODE_DEDICATED;
+	else if (strncmp(buf, "pass-through", 12) == 0)
+		mode = V_SET_ACTIVE_MODE_PASSTHROUGH;
+	else if (strncmp(buf, "BC1.2-DCP", 9) == 0)
+		mode = V_SET_ACTIVE_MODE_BC12_DCP;
+	else if (strncmp(buf, "BC1.2-SDP", 9) == 0)
+		mode = V_SET_ACTIVE_MODE_BC12_SDP;
+	else if (strncmp(buf, "BC1.2-CDP", 9) == 0)
+		mode = V_SET_ACTIVE_MODE_BC12_CDP;
+	else
+		return -EINVAL;
+
+	if (info->pdata) {
+		gpiod_set_value_cansleep(info->pdata->gpiod_em,
+					 (mode & F_EM_EN_SET) ? 1 : 0);
+		gpiod_set_value_cansleep(info->pdata->gpiod_m1,
+					 (mode & F_M1_SET) ? 1 : 0);
+		gpiod_set_value_cansleep(info->pdata->gpiod_m2,
+					 (mode & F_M2_SET) ? 1 : 0);
+	} else {
+		ret = regmap_update_bits(info->regmap, UCS1002_REG_SWITCH_CFG,
+					 V_SET_ACTIVE_MODE_MASK, mode);
+		if (ret < 0)
+			return ret;
+	}
+
+	return count;
+}
+
+static ssize_t ucs1002_sysfs_show_enabled(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct power_supply *psy = dev_get_drvdata(dev);
+	struct ucs1002_info *info = power_supply_get_drvdata(psy);
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n", info->enabled);
+}
+
+static ssize_t ucs1002_sysfs_set_enabled(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct power_supply *psy = dev_get_drvdata(dev);
+	struct ucs1002_info *info = power_supply_get_drvdata(psy);
+	long val;
+	int ret;
+
+	if (kstrtol(buf, 10, &val) < 0)
+		return -EINVAL;
+
+	ret = ucs1002_power_enable(info, val ? true : false);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static ssize_t ucs1002_sysfs_show_profile(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct power_supply *psy = dev_get_drvdata(dev);
+	struct ucs1002_info *info = power_supply_get_drvdata(psy);
+	int idx, regval, ret, len = 0;
+
+	/*
+	 * Read Custom Emulation Profile
+	 */
+
+	/* read registers 40h-4Ch (Custom Emulation Configuration) */
+	for (idx = 0; idx < V_CUSTOM_EMU_CFG_NREGS; idx++) {
+		ret = regmap_read(info->regmap,
+				  UCS1002_REG_CUSTOM_EMU_CFG_BASE + idx,
+				  &regval);
+		if (ret < 0)
+			return ret;
+
+		len += scnprintf(&buf[len], PAGE_SIZE, "%02x ", regval);
+	}
+
+	/* read register 16h (Emulation Configuration) */
+	ret = regmap_read(info->regmap, UCS1002_REG_EMU_CFG, &regval);
+	if (ret < 0)
+		return ret;
+
+	len += scnprintf(&buf[len], PAGE_SIZE, "%02x ", regval);
+
+	/* read register 19h (Current Limit) */
+	ret = regmap_read(info->regmap, UCS1002_REG_ILIMIT, &regval);
+	if (ret < 0)
+		return ret;
+
+	len += scnprintf(&buf[len], PAGE_SIZE, "%02x ", regval);
+
+	/* read register 25h (High-speed Switch Configuration) */
+	ret = regmap_read(info->regmap, UCS1002_REG_HS_SWITCH_CFG, &regval);
+	if (ret < 0)
+		return ret;
+
+	len += scnprintf(&buf[len], PAGE_SIZE, "%02x ", regval);
+
+	/* read register 51h (Custom Current Limiting Behavior Config) */
+	ret = regmap_read(info->regmap, UCS1002_REG_CUSTOM_ILIMIT_CFG,
+			  &regval);
+	if (ret < 0)
+		return ret;
+
+	len += scnprintf(&buf[len], PAGE_SIZE, "%02x\n", regval);
+
+	return len;
+}
+
+static ssize_t ucs1002_sysfs_set_profile(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct power_supply *psy = dev_get_drvdata(dev);
+	struct ucs1002_info *info = power_supply_get_drvdata(psy);
+	const char *delim = " ";
+	char profile_data[256];
+	char *token, *str_ptr;
+	int regval[UCS1002_PROFILE_NREGS];
+	int idx = 0, ret;
+
+	strncpy(profile_data, buf, 256);
+	str_ptr = &profile_data[0];
+
+	while (str_ptr && (idx < UCS1002_PROFILE_NREGS)) {
+		token = strsep(&str_ptr, delim);
+		if (kstrtoint(token, 0, &regval[idx])) {
+			dev_dbg(dev, "failed to convert %s to integer\n",
+				token);
+			return -EINVAL;
+		}
+		idx++;
+	}
+
+	if (idx != UCS1002_PROFILE_NREGS) {
+		dev_dbg(dev, "failed to set emulation profile (%d)\n", idx);
+		return -EINVAL;
+	}
+
+	/*
+	 * Write Custom Emulation Profile
+	 */
+
+	/* write registers 40h-4Ch (Custom Emulation Configuration) */
+	for (idx = 0; idx < V_CUSTOM_EMU_CFG_NREGS; idx++) {
+		ret = regmap_write(info->regmap,
+				   UCS1002_REG_CUSTOM_EMU_CFG_BASE + idx,
+				   regval[idx]);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* write register 16h (Emulation Configuration) */
+	ret = regmap_write(info->regmap, UCS1002_REG_EMU_CFG,
+			   regval[idx++]);
+	if (ret < 0)
+		return ret;
+
+	/* write register 19h (Current Limit) */
+	ret = regmap_write(info->regmap, UCS1002_REG_ILIMIT, regval[idx++]);
+	if (ret < 0)
+		return ret;
+
+	/* write register 25h (High-speed Switch Configuration) */
+	ret = regmap_write(info->regmap, UCS1002_REG_HS_SWITCH_CFG,
+			   regval[idx++]);
+	if (ret < 0)
+		return ret;
+
+	/* write register 51h (Custom Current Limiting Behavior Config) */
+	ret = regmap_write(info->regmap, UCS1002_REG_CUSTOM_ILIMIT_CFG,
+			   regval[idx]);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+const char * const ucs1002_pwr_state_values[] = {
+	"sleep", "detect", "active", "error"
+};
+
+static ssize_t ucs1002_sysfs_show_state(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	int ret, regval;
+	struct power_supply *psy = dev_get_drvdata(dev);
+	struct ucs1002_info *info = power_supply_get_drvdata(psy);
+
+	ret = regmap_read(info->regmap, UCS1002_REG_PIN_STATUS, &regval);
+	if (ret < 0)
+		return -EINVAL;
+
+	regval &= UCS1002_PWR_STATE_MASK;
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n",
+			 ucs1002_pwr_state_values[regval]);
+}
+
+static DEVICE_ATTR(curr_alarm, S_IRUGO, ucs1002_sysfs_show_curr_alarm, NULL);
+static DEVICE_ATTR(enabled, S_IWUSR | S_IRUGO, ucs1002_sysfs_show_enabled,
+		   ucs1002_sysfs_set_enabled);
+static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, ucs1002_sysfs_show_active_mode,
+		   ucs1002_sysfs_set_active_mode);
+static DEVICE_ATTR(profile, S_IWUSR | S_IRUGO, ucs1002_sysfs_show_profile,
+		   ucs1002_sysfs_set_profile);
+static DEVICE_ATTR(state, S_IRUGO, ucs1002_sysfs_show_state, NULL);
+
+static struct attribute *ucs1002_specific_attr[] = {
+	&dev_attr_curr_alarm.attr,
+	&dev_attr_enabled.attr,
+	&dev_attr_mode.attr,
+	&dev_attr_profile.attr,
+	&dev_attr_state.attr,
+	NULL,
+};
+
+static const struct attribute_group ucs1002_attr_group = {
+	.attrs = ucs1002_specific_attr,
+};
+
+static irqreturn_t ucs1002_charger_irq(int irq, void *data)
+{
+	int ret, regval;
+	bool present;
+	struct ucs1002_info *info = data;
+
+	present = info->present;
+
+	ret = regmap_read(info->regmap, UCS1020_REG_OTHER_STATUS, &regval);
+	if (ret < 0)
+		return IRQ_HANDLED;
+
+	/* update attached status */
+	info->present = (regval & F_ADET_PIN) ? true : false;
+
+	/* notify the change */
+	if (present != info->present)
+		power_supply_changed(info->charger);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ucs1002_alert_irq(int irq, void *data)
+{
+	int ret, regval;
+	struct ucs1002_info *info = data;
+
+	ret = regmap_read(info->regmap, UCS1002_REG_INTERRUPT_STATUS, &regval);
+	if (ret < 0)
+		return IRQ_HANDLED;
+
+	/* update current alarm status */
+	info->curr_alarm = (regval & F_OVER_ILIM) ? true : false;
+
+	/* over current alarm */
+	if (regval & F_OVER_ILIM)
+		power_supply_changed(info->charger);
+
+	return IRQ_HANDLED;
+}
+
+static int ucs1002_poll_task(void *data)
+{
+	set_freezable();
+
+	while (!kthread_should_stop()) {
+		schedule_timeout_interruptible(POLL_INTERVAL);
+		try_to_freeze();
+		ucs1002_charger_irq(-1, data);
+		ucs1002_alert_irq(-1, data);
+	}
+	return 0;
+}
+
+static int ucs1002_get_control_gpios(struct ucs1002_info *info)
+{
+	int ret, regval;
+	struct device *dev = &info->client->dev;
+
+	info->pdata = devm_kzalloc(dev, sizeof(struct ucs1002_platform_data),
+				   GFP_KERNEL);
+	if (!info->pdata)
+		return -ENOMEM;
+
+	/* gpio for chip EM_EN pin */
+	info->pdata->gpiod_em = devm_gpiod_get_index(dev, "control", 0,
+						     GPIOD_OUT_HIGH);
+	if (IS_ERR(info->pdata->gpiod_em)) {
+		dev_err(dev, "unable to claim EM_EN gpio\n");
+		return PTR_ERR(info->pdata->gpiod_em);
+	}
+
+	/* gpio for chip M1 pin */
+	info->pdata->gpiod_m1 = devm_gpiod_get_index(dev, "control", 1,
+						     GPIOD_OUT_LOW);
+	if (IS_ERR(info->pdata->gpiod_m1)) {
+		dev_err(dev, "unable to claim M1 gpio\n");
+		return PTR_ERR(info->pdata->gpiod_m1);
+	}
+
+	/* gpio for chip M2 pin */
+	info->pdata->gpiod_m2 = devm_gpiod_get_index(dev, "control", 2,
+						     GPIOD_OUT_LOW);
+	if (IS_ERR(info->pdata->gpiod_m2)) {
+		dev_err(dev, "unable to claim EM_EN gpio\n");
+		return PTR_ERR(info->pdata->gpiod_m2);
+	}
+
+	/* Read the polarity setting determined by the SEL pin */
+	ret = regmap_read(info->regmap, UCS1002_REG_PIN_STATUS,
+			  &regval);
+	if (ret < 0)
+		return ret;
+
+	/* gpio for chip PWR_EN pin - power off */
+	info->pdata->gpiod_pwr = devm_gpiod_get_index(dev, "control", 3,
+						      (regval & F_SEL_PIN) ?
+						      GPIOD_OUT_LOW :
+						      GPIOD_OUT_HIGH);
+	if (IS_ERR(info->pdata->gpiod_pwr)) {
+		dev_err(dev, "unable to claim PWR_EN gpio\n");
+		return PTR_ERR(info->pdata->gpiod_pwr);
+	}
+
+	return 0;
+}
+
+static int ucs1002_probe(struct i2c_client *client,
+			 const struct i2c_device_id *dev_id)
+{
+	int ret, regval;
+	u32 property;
+	struct ucs1002_info *info;
+	struct device *dev = &client->dev;
+	struct power_supply_config ucs1002_charger_config = {};
+
+	info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->regmap = devm_regmap_init_i2c(client, &ucs1002_regmap_config);
+	if (IS_ERR(info->regmap)) {
+		ret = PTR_ERR(info->regmap);
+		dev_err(dev, "regmap initialization failed: %d\n", ret);
+		return ret;
+	}
+
+	info->client = client;
+	info->curr_alarm = false;
+	info->enabled = false;
+	info->present = false;
+
+	info->irq_a_det = irq_of_parse_and_map(dev->of_node, 0);
+	info->irq_alert = irq_of_parse_and_map(dev->of_node, 1);
+
+	i2c_set_clientdata(client, info);
+
+	ucs1002_charger_config.of_node = dev->of_node;
+	ucs1002_charger_config.drv_data = info;
+
+	ret = regmap_read(info->regmap, UCS1002_REG_PRODUCT_ID, &regval);
+	if (ret < 0)
+		return ret;
+
+	if (regval != UCS1002_PRODUCT_ID) {
+		dev_err(dev,
+			"Product ID does not match (0x%02x != 0x%02x)\n",
+			regval, UCS1002_PRODUCT_ID);
+		return -ENODEV;
+	}
+
+	dev_info(dev, "registered with product id 0x%02x\n",
+		 UCS1002_PRODUCT_ID);
+
+	/* Enable charge rationing by default */
+	ret = regmap_update_bits(info->regmap, UCS1002_REG_GENERAL_CFG,
+				 F_RATION_EN, F_RATION_EN);
+	if (ret < 0)
+		return ret;
+
+	if (!device_property_present(dev, "control-gpios")) {
+		dev_dbg(dev, "set active mode selection through i2c\n");
+		/*
+		 * Ignore the M1, M2, PWR_EN, and EM_EN pin states. Set active
+		 * mode selection to Dedicated Charger Emulation Cycle.
+		 *
+		 * #M1    #M2    EM_EN
+		 *  0      0       1   - Dedicated Charger Emulation Cycle
+		 *
+		 */
+		ret = regmap_update_bits(info->regmap, UCS1002_REG_SWITCH_CFG,
+					 F_PIN_IGNORE | F_EM_EN_SET | F_M2_SET |
+					 F_M1_SET, F_PIN_IGNORE | F_EM_EN_SET);
+		if (ret < 0)
+			return ret;
+	} else {
+		dev_dbg(dev, "set active mode selection through pins\n");
+
+		/*
+		 * The Active mode selection and power state will be set by the
+		 * OR'd combination of the M1, M2, PWR_EN, and EM_EN pin states
+		 * and the corresponding bit states.
+		 */
+		ret = regmap_update_bits(info->regmap, UCS1002_REG_SWITCH_CFG,
+					 F_PIN_IGNORE | F_EM_EN_SET | F_M2_SET |
+					 F_M1_SET | F_PWR_EN_SET, 0);
+		if (ret < 0)
+			return ret;
+
+		/*
+		 * PIN_IGNORE mode not set, so EM, M1 and M2 pins must be
+		 * defined.
+		 */
+		ret = ucs1002_get_control_gpios(info);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * The current limit is based on the resistor on the COMM_SEL / ILIM
+	 * pin and this value cannot be changed to be higher than hardware
+	 * set value. If the property is not set, the value set by hardware is
+	 * the default.
+	 */
+	ret = device_property_read_u32(dev, "microchip,limit-microamps",
+				       &property);
+	if (ret == 0)
+		ucs1002_set_max_current(info, property);
+
+	info->charger = devm_power_supply_register(dev, &ucs1002_charger_desc,
+						   &ucs1002_charger_config);
+	if (IS_ERR(info->charger)) {
+		dev_err(dev, "failed to register power supply\n");
+		return PTR_ERR(info->charger);
+	}
+
+	ret = sysfs_create_group(&info->charger->dev.kobj, &ucs1002_attr_group);
+	if (ret < 0) {
+		dev_err(dev, "can't create sysfs entries\n");
+		return ret;
+	}
+
+	/* Turn on the port power switch */
+	ucs1002_power_enable(info, true);
+
+	if (info->irq_a_det && info->irq_alert) {
+		ret = devm_request_threaded_irq(dev, info->irq_a_det, NULL,
+						ucs1002_charger_irq,
+						IRQF_TRIGGER_FALLING |
+						IRQF_TRIGGER_RISING |
+						IRQF_ONESHOT,
+						"ucs1002-a_det", info);
+		if (ret) {
+			dev_err(dev, "failed to request A_DET threaded irq\n");
+			goto fail_remove_group;
+		}
+
+		ret = devm_request_threaded_irq(dev, info->irq_alert, NULL,
+						ucs1002_alert_irq,
+						IRQF_TRIGGER_FALLING |
+						IRQF_TRIGGER_RISING |
+						IRQF_ONESHOT,
+						"ucs1002-alert", info);
+		if (ret) {
+			dev_err(dev, "failed to request ALERT threaded irq\n");
+			goto fail_remove_group;
+		}
+	} else {
+		dev_warn(dev, "no IRQ support, using polling mode\n");
+		info->poll_task = kthread_run(ucs1002_poll_task, info,
+					      "kucs1002");
+		if (IS_ERR(info->poll_task)) {
+			ret = PTR_ERR(info->poll_task);
+			dev_err(dev, "unable to run kthread err (%d)\n", ret);
+			goto fail_remove_group;
+		}
+	}
+
+	return 0;
+
+fail_remove_group:
+	sysfs_remove_group(&info->charger->dev.kobj, &ucs1002_attr_group);
+	return ret;
+}
+
+static int ucs1002_remove(struct i2c_client *client)
+{
+	struct ucs1002_info *info = i2c_get_clientdata(client);
+
+	if (info->poll_task)
+		kthread_stop(info->poll_task);
+
+	sysfs_remove_group(&info->charger->dev.kobj, &ucs1002_attr_group);
+
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_OF)
+static const struct of_device_id ucs1002_of_match[] = {
+	{ .compatible = "microchip,ucs1002", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ucs1002_of_match);
+#endif
+
+static const struct i2c_device_id ucs1002_ids[] = {
+	{"ucs1002", 0},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(i2c, ucs1002_ids);
+
+static struct i2c_driver ucs1002_driver = {
+	.driver = {
+		   .name = "ucs1002",
+		   .of_match_table = of_match_ptr(ucs1002_of_match),
+	},
+	.probe = ucs1002_probe,
+	.remove = ucs1002_remove,
+	.id_table = ucs1002_ids,
+};
+module_i2c_driver(ucs1002_driver);
+
+MODULE_DESCRIPTION("Microchip UCS1002 Programmable USB Port Power Controller");
+MODULE_AUTHOR("Enric Balletbo Serra <enric.balletbo@...labora.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.1.0

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