Date:	Thu,  2 Apr 2015 00:13:54 +0530
From:	Ramakrishna Pallala <ramakrishna.pallala@...el.com>
To:	linux-kernel@...r.kernel.org,
	MyungJoo Ham <myungjoo.ham@...sung.com>,
	Chanwoo Choi <cw00.choi@...sung.com>,
	Samuel Ortiz <sameo@...ux.intel.com>,
	Carlo Caione <carlo@...one.org>
Cc:	Jacob Pan <jacob.jun.pan@...ux.intel.com>,
	Pallala Ramakrishna <ramakrishna.pallala@...el.com>
Subject: [PATCH 2/2] extcon-axp288: Add axp288 extcon driver support

This patch adds the extcon support for AXP288 PMIC which
has the BC1.2 charger detection capability. Additionally
it also adds the USB mux switching support b/w SOC and PMIC
based on GPIO control.

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@...el.com>
---
 drivers/extcon/Kconfig         |    7 +
 drivers/extcon/Makefile        |    1 +
 drivers/extcon/extcon-axp288.c |  479 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 487 insertions(+)
 create mode 100644 drivers/extcon/extcon-axp288.c

diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index 6a1f7de..b8627f7 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -93,4 +93,11 @@ config EXTCON_SM5502
 	  Silicon Mitus SM5502. The SM5502 is a USB port accessory
 	  detector and switch.
 
+config EXTCON_AXP288
+	tristate "AXP288 EXTCON support"
+	depends on MFD_AXP20X && USB_PHY
+	help
+	  Say Y here to enable support for USB peripheral detection
+	  and USB MUX switching by AXP288 PMIC.
+
 endif # MULTISTATE_SWITCH
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index 0370b42..832ad79 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_EXTCON_MAX8997)	+= extcon-max8997.o
 obj-$(CONFIG_EXTCON_PALMAS)	+= extcon-palmas.o
 obj-$(CONFIG_EXTCON_RT8973A)	+= extcon-rt8973a.o
 obj-$(CONFIG_EXTCON_SM5502)	+= extcon-sm5502.o
+obj-$(CONFIG_EXTCON_AXP288)	+= extcon-axp288.o
diff --git a/drivers/extcon/extcon-axp288.c b/drivers/extcon/extcon-axp288.c
new file mode 100644
index 0000000..7228ae4
--- /dev/null
+++ b/drivers/extcon/extcon-axp288.c
@@ -0,0 +1,479 @@
+/*
+ * extcon-axp288.c - X-Power AXP288 PMIC extcon cable detection driver
+ *
+ * Copyright (C) 2015 Intel Corporation
+ * Ramakrishna Pallala <ramakrishna.pallala@...el.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.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/usb/phy.h>
+#include <linux/notifier.h>
+#include <linux/extcon.h>
+#include <linux/regmap.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mfd/axp20x.h>
+
+#define AXP288_PS_STAT_REG		0x00
+#define PS_STAT_VBUS_TRIGGER		(1 << 0)
+#define PS_STAT_BAT_CHRG_DIR		(1 << 2)
+#define PS_STAT_VBUS_ABOVE_VHOLD	(1 << 3)
+#define PS_STAT_VBUS_VALID		(1 << 4)
+#define PS_STAT_VBUS_PRESENT		(1 << 5)
+
+#define AXP288_BC_GLOBAL_REG		0x2c
+#define BC_GLOBAL_RUN			(1 << 0)
+#define BC_GLOBAL_DET_STAT		(1 << 2)
+#define BC_GLOBAL_DBP_TOUT		(1 << 3)
+#define BC_GLOBAL_VLGC_COM_SEL		(1 << 4)
+#define BC_GLOBAL_DCD_TOUT_MASK		0x60
+#define BC_GLOBAL_DCD_TOUT_300MS	0x0
+#define BC_GLOBAL_DCD_TOUT_100MS	0x1
+#define BC_GLOBAL_DCD_TOUT_500MS	0x2
+#define BC_GLOBAL_DCD_TOUT_900MS	0x3
+#define BC_GLOBAL_DCD_DET_SEL		(1 << 7)
+
+#define AXP288_BC_VBUS_CNTL_REG		0x2d
+#define VBUS_CNTL_DPDM_PD_EN		(1 << 4)
+#define VBUS_CNTL_DPDM_FD_EN		(1 << 5)
+#define VBUS_CNTL_FIRST_PO_STAT		(1 << 6)
+
+#define AXP288_BC_USB_STAT_REG		0x2e
+#define USB_STAT_BUS_STAT_MASK		0x0f
+#define USB_STAT_BUS_STAT_OFFSET	0
+#define USB_STAT_BUS_STAT_ATHD		0x0
+#define USB_STAT_BUS_STAT_CONN		0x1
+#define USB_STAT_BUS_STAT_SUSP		0x2
+#define USB_STAT_BUS_STAT_CONF		0x3
+#define USB_STAT_USB_SS_MODE		(1 << 4)
+#define USB_STAT_DEAD_BAT_DET		(1 << 6)
+#define USB_STAT_DBP_UNCFG		(1 << 7)
+
+#define AXP288_BC_DET_STAT_REG		0x2f
+#define DET_STAT_MASK			0xe0
+#define DET_STAT_OFFSET			5
+#define DET_STAT_SDP			0x1
+#define DET_STAT_CDP			0x2
+#define DET_STAT_DCP			0x3
+
+#define AXP288_PS_BOOT_REASON_REG	0x2
+
+#define AXP288_PWRSRC_IRQ_CFG_REG	0x40
+#define PWRSRC_IRQ_CFG_MASK		0x1c
+
+#define AXP288_BC12_IRQ_CFG_REG		0x45
+#define BC12_IRQ_CFG_MASK		0x2
+
+#define AXP288_PWRSRC_INTR_NUM		4
+
+#define AXP288_DRV_NAME			"extcon-axp288"
+
+#define AXP288_EXTCON_CABLE_SDP		"Slow-charger"
+#define AXP288_EXTCON_CABLE_CDP		"Charge-downstream"
+#define AXP288_EXTCON_CABLE_DCP		"Fast-charger"
+
+#define EXTCON_GPIO_MUX_SEL_PMIC	0
+#define EXTCON_GPIO_MUX_SEL_SOC		1
+
+enum {
+	VBUS_FALLING_IRQ = 0,
+	VBUS_RISING_IRQ,
+	MV_CHNG_IRQ,
+	BC_USB_CHNG_IRQ,
+};
+
+static const char *axp288_extcon_cables[] = {
+	AXP288_EXTCON_CABLE_SDP,
+	AXP288_EXTCON_CABLE_CDP,
+	AXP288_EXTCON_CABLE_DCP,
+	NULL,
+};
+
+struct axp288_extcon_info {
+	struct platform_device *pdev;
+	struct regmap *regmap;
+	struct regmap_irq_chip_data *regmap_irqc;
+	struct axp288_extcon_pdata *pdata;
+	int irq[AXP288_PWRSRC_INTR_NUM];
+	struct extcon_dev *edev;
+	struct usb_phy *otg;
+	struct notifier_block extcon_nb;
+	struct extcon_specific_cable_nb cable;
+	bool is_sdp;
+	bool usb_id_short;
+};
+
+static char *pwr_up_down_info[] = {
+	/* bit 0 */ "Last wake caused by user pressing the power button",
+	/* bit 2 */ "Last wake caused by a charger insertion",
+	/* bit 1 */ "Last wake caused by a battery insertion",
+	/* bit 3 */ "Last wake caused by SOC initiated global reset",
+	/* bit 4 */ "Last wake caused by cold reset",
+	/* bit 5 */ "Last shutdown caused by PMIC UVLO threshold",
+	/* bit 6 */ "Last shutdown caused by SOC initiated cold off",
+	/* bit 7 */ "Last shutdown caused by user pressing the power button",
+	NULL,
+};
+
+/*
+ * Decode and log the given "reset source indicator"
+ * register and then clear it.
+ */
+static void axp288_extcon_log_rsi(struct axp288_extcon_info *info,
+				char **pwrsrc_rsi_info, int reg)
+{
+	char **rsi;
+	unsigned int val, i, clear_mask = 0;
+	int ret;
+
+	ret = regmap_read(info->regmap, reg, &val);
+	for (i = 0, rsi = pwrsrc_rsi_info; *rsi; rsi++, i++) {
+		if (val & BIT(i)) {
+			dev_dbg(&info->pdev->dev, "%s\n", *rsi);
+			clear_mask |= BIT(i);
+		}
+	}
+
+	/* Clear the register value for next reboot (write 1 to clear bit) */
+	regmap_write(info->regmap, reg, clear_mask);
+}
+
+static int handle_chrg_det_event(struct axp288_extcon_info *info)
+{
+	static bool notify_otg, notify_charger;
+	static char *cable;
+	int ret, stat, cfg, pwr_stat;
+	u8 chrg_type;
+	bool vbus_attach = false;
+
+	ret = regmap_read(info->regmap, AXP288_PS_STAT_REG, &pwr_stat);
+	if (ret < 0) {
+		dev_err(&info->pdev->dev, "vbus status read error\n");
+		return ret;
+	}
+
+	vbus_attach = (pwr_stat & PS_STAT_VBUS_PRESENT) && !info->usb_id_short;
+	if (vbus_attach) {
+		dev_dbg(&info->pdev->dev, "vbus present\n");
+	} else {
+		dev_dbg(&info->pdev->dev, "vbus not present\n");
+		goto notify_otg;
+	}
+
+	/* Check charger detection completion status */
+	ret = regmap_read(info->regmap, AXP288_BC_GLOBAL_REG, &cfg);
+	if (ret < 0)
+		goto dev_det_ret;
+	if (cfg & BC_GLOBAL_DET_STAT) {
+		dev_dbg(&info->pdev->dev, "charger detection not complete!!\n");
+		goto dev_det_ret;
+	}
+
+	ret = regmap_read(info->regmap, AXP288_BC_DET_STAT_REG, &stat);
+	if (ret < 0)
+		goto dev_det_ret;
+	dev_dbg(&info->pdev->dev, "stat:%x, cfg:%x\n", stat, cfg);
+
+	chrg_type = (stat & DET_STAT_MASK) >> DET_STAT_OFFSET;
+	info->is_sdp = false;
+
+	if (chrg_type == DET_STAT_SDP) {
+		dev_dbg(&info->pdev->dev, "sdp cable connecetd\n");
+		notify_otg = true;
+		notify_charger = true;
+		info->is_sdp = true;
+		cable = AXP288_EXTCON_CABLE_SDP;
+	} else if (chrg_type == DET_STAT_CDP) {
+		dev_dbg(&info->pdev->dev, "cdp cable connecetd\n");
+		notify_otg = true;
+		notify_charger = true;
+		cable = AXP288_EXTCON_CABLE_CDP;
+	} else if (chrg_type == DET_STAT_DCP) {
+		dev_dbg(&info->pdev->dev, "dcp cable connecetd\n");
+		notify_charger = true;
+		cable = AXP288_EXTCON_CABLE_DCP;
+	} else {
+		dev_warn(&info->pdev->dev,
+			"disconnect or unknown or ID event\n");
+	}
+
+notify_otg:
+	if (notify_otg) {
+		/*
+		 * If VBUS is absent Connect D+/D- lines to PMIC for BC
+		 * detection. Else connect them to SOC for USB communication.
+		 */
+		if (info->pdata->gpio_mux_cntl != NULL)
+			gpiod_set_value(info->pdata->gpio_mux_cntl,
+				vbus_attach ? EXTCON_GPIO_MUX_SEL_SOC
+						: EXTCON_GPIO_MUX_SEL_PMIC);
+
+		atomic_notifier_call_chain(&info->otg->notifier,
+			vbus_attach ? USB_EVENT_VBUS : USB_EVENT_NONE, NULL);
+	}
+
+	if (notify_charger)
+		extcon_set_cable_state(info->edev, cable, vbus_attach);
+
+	/* Clear the flags on disconnect event */
+	if (!vbus_attach) {
+		notify_otg = false;
+		notify_charger = false;
+	}
+
+	return 0;
+
+dev_det_ret:
+	if (ret < 0)
+		dev_warn(&info->pdev->dev, "BC Mod detection error\n");
+
+	return ret;
+}
+
+static irqreturn_t axp288_extcon_isr(int irq, void *data)
+{
+	struct axp288_extcon_info *info = data;
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < AXP288_PWRSRC_INTR_NUM; i++) {
+		if (info->irq[i] == irq)
+			break;
+	}
+
+	if (i == AXP288_PWRSRC_INTR_NUM) {
+		dev_warn(&info->pdev->dev, "spurious interrupt!!\n");
+		return IRQ_NONE;
+	}
+
+	ret = handle_chrg_det_event(info);
+	if (ret < 0)
+		dev_warn(&info->pdev->dev, "error in PWRSRC INT handling\n");
+
+	return IRQ_HANDLED;
+}
+
+static int axp288_extcon_registration(struct axp288_extcon_info *info)
+{
+	int ret;
+
+	/* Register with extcon */
+	info->edev = devm_kzalloc(&info->pdev->dev,
+				sizeof(struct extcon_dev), GFP_KERNEL);
+	if (!info->edev)
+		return -ENOMEM;
+
+	info->edev->name = "extcon-axp288";
+	info->edev->supported_cable = axp288_extcon_cables;
+	ret = extcon_dev_register(info->edev);
+	if (ret)
+		dev_err(&info->pdev->dev, "extcon registration failed!!\n");
+
+	return ret;
+}
+
+static inline bool is_usb_host_mode(struct extcon_dev *evdev)
+{
+	return !!evdev->state;
+}
+
+static int axp288_handle_extcon_event(struct notifier_block *nb,
+				   unsigned long event, void *param)
+{
+	struct axp288_extcon_info *info =
+	    container_of(nb, struct axp288_extcon_info, extcon_nb);
+	struct extcon_dev *edev = param;
+	int usb_host = is_usb_host_mode(edev);
+
+	dev_info(&info->pdev->dev,
+		"[extcon notification] evt:USB-Host val:%s\n",
+		usb_host ? "Connected" : "Disconnected");
+
+	/*
+	 * Set usb_id_short flag to avoid running charger detection logic
+	 * in case usb host.
+	 */
+	info->usb_id_short = usb_host;
+
+	/*
+	 * Connect the USB mux to SOC in case of usb host else connect
+	 * it to PMIC.
+	 */
+	if (info->pdata->gpio_mux_cntl != NULL) {
+		dev_dbg(&info->pdev->dev,
+			"usb_id_short=%d\n", info->usb_id_short);
+		if (info->usb_id_short)
+			gpiod_set_value(info->pdata->gpio_mux_cntl,
+					EXTCON_GPIO_MUX_SEL_SOC);
+		else
+			gpiod_set_value(info->pdata->gpio_mux_cntl,
+					EXTCON_GPIO_MUX_SEL_PMIC);
+	}
+
+	return NOTIFY_OK;
+}
+
+static int axp288_init_gpio_mux_cntl(struct axp288_extcon_info *info)
+{
+	int ret;
+
+	ret = gpio_request(desc_to_gpio(info->pdata->gpio_mux_cntl), "USB_MUX");
+	if (ret < 0) {
+		dev_err(&info->pdev->dev,
+			"usb mux gpio request failed:gpio=%d\n",
+			desc_to_gpio(info->pdata->gpio_mux_cntl));
+		return ret;
+	}
+	gpiod_direction_output(info->pdata->gpio_mux_cntl,
+					EXTCON_GPIO_MUX_SEL_PMIC);
+
+	info->extcon_nb.notifier_call = axp288_handle_extcon_event;
+	ret = extcon_register_interest(&info->cable, NULL,
+				"USB-Host", &info->extcon_nb);
+	if (ret) {
+		dev_err(&info->pdev->dev, "failed to register extcon notifier\n");
+		return ret;
+	}
+
+	if (info->cable.edev)
+		info->usb_id_short =
+				is_usb_host_mode(info->cable.edev);
+	if (info->usb_id_short)
+		gpiod_set_value(info->pdata->gpio_mux_cntl,
+					EXTCON_GPIO_MUX_SEL_SOC);
+
+	return 0;
+}
+
+static int axp288_extcon_probe(struct platform_device *pdev)
+{
+	struct axp288_extcon_info *info;
+	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
+	int ret, i, pirq;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->pdev = pdev;
+	info->regmap = axp20x->regmap;
+	info->regmap_irqc = axp20x->regmap_irqc;
+	info->pdata = pdev->dev.platform_data;
+
+	if (!info->pdata) {
+		/* TODO: Try ACPI provided pdata via device properties */
+		if (!device_property_present(&pdev->dev,
+					"axp288_extcon_data\n"))
+			dev_err(&pdev->dev, "no platform data\n");
+		return -ENODEV;
+	}
+	platform_set_drvdata(pdev, info);
+
+	axp288_extcon_log_rsi(info, pwr_up_down_info,
+				AXP288_PS_BOOT_REASON_REG);
+
+	/* Register extcon device */
+	ret = axp288_extcon_registration(info);
+	if (ret < 0)
+		goto extcon_reg_failed;
+
+	/* Get otg transceiver phy */
+	info->otg = usb_get_phy(USB_PHY_TYPE_USB2);
+	if (IS_ERR(info->otg)) {
+		dev_warn(&info->pdev->dev, "Failed to get otg transceiver!!\n");
+		ret = PTR_ERR(info->otg);
+		goto otg_reg_failed;
+	}
+
+	for (i = 0; i < AXP288_PWRSRC_INTR_NUM; i++) {
+		pirq = platform_get_irq(pdev, i);
+		info->irq[i] = regmap_irq_get_virq(info->regmap_irqc, pirq);
+		if (info->irq[i] < 0) {
+			dev_warn(&info->pdev->dev,
+				"regmap_irq get virq failed for IRQ %d: %d\n",
+				pirq, info->irq[i]);
+			info->irq[i] = -1;
+			goto intr_reg_failed;
+		}
+		ret = request_threaded_irq(info->irq[i],
+				NULL, axp288_extcon_isr,
+				IRQF_ONESHOT, AXP288_DRV_NAME, info);
+		if (ret) {
+			dev_err(&pdev->dev, "request_irq fail :%d err:%d\n",
+							info->irq[i], ret);
+			goto intr_reg_failed;
+		}
+	}
+
+	/* Set up gpio control for USB Mux */
+	if (info->pdata->gpio_mux_cntl != NULL) {
+		ret = axp288_init_gpio_mux_cntl(info);
+		if (ret < 0)
+			goto intr_reg_failed;
+	}
+
+	/* Unmask VBUS interrupt */
+	regmap_write(info->regmap, AXP288_PWRSRC_IRQ_CFG_REG,
+						PWRSRC_IRQ_CFG_MASK);
+	regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,
+						BC_GLOBAL_RUN, 0);
+	/* Unmask the BC1.2 complte interrupts */
+	regmap_write(info->regmap, AXP288_BC12_IRQ_CFG_REG, BC12_IRQ_CFG_MASK);
+	/* Enable the charger detection logic */
+	regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,
+					BC_GLOBAL_RUN, BC_GLOBAL_RUN);
+
+	return 0;
+
+intr_reg_failed:
+	for (; i > 0; i--) {
+		free_irq(info->irq[i - 1], info);
+		info->irq[i - 1] = -1;
+	}
+	usb_put_phy(info->otg);
+otg_reg_failed:
+	extcon_dev_unregister(info->edev);
+extcon_reg_failed:
+	return ret;
+}
+
+static int axp288_extcon_remove(struct platform_device *pdev)
+{
+	struct axp288_extcon_info *info = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < AXP288_PWRSRC_INTR_NUM; i++)
+		free_irq(info->irq[i], info);
+	usb_put_phy(info->otg);
+	extcon_dev_unregister(info->edev);
+	return 0;
+}
+
+static struct platform_driver axp288_extcon_driver = {
+	.probe = axp288_extcon_probe,
+	.remove = axp288_extcon_remove,
+	.driver = {
+		.name = AXP288_DRV_NAME,
+	},
+};
+module_platform_driver(axp288_extcon_driver);
+
+MODULE_AUTHOR("Ramakrishna Pallala <ramakrishna.pallala@...el.com>");
+MODULE_DESCRIPTION("X-Powers AXP288 extcon driver");
+MODULE_LICENSE("GPL");
-- 
1.7.9.5

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