extcon: Palmas Extcon Driver

This is the driver for the USB comparator built into the palmas chip. It
handles the various USB OTG events that can be generated by cable
insertion/removal.

Signed-off-by: Graeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: Moiz Sonasath <m-sonasath@ti.com>
Signed-off-by: Ruchika Kharwar <ruchika@ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: George Cherian <george.cherian@ti.com>
[kishon@ti.com: adapted palmas usb driver to use the extcon framework]
Signed-off-by: Sebastien Guiriec <s-guiriec@ti.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/extcon/extcon-twl.txt

@@ -0,0 +1,15 @@
+EXTCON FOR TWL CHIPS
+
+PALMAS USB COMPARATOR
+Required Properties:
+ - compatible : Should be "ti,palmas-usb" or "ti,twl6035-usb"
+ - vbus-supply : phandle to the regulator device tree node.
+
+Optional Properties:
+ - ti,wakeup : To enable the wakeup comparator in probe
+
+palmas-usb {
+       compatible = "ti,twl6035-usb", "ti,palmas-usb";
+       vbus-supply = <&smps10_reg>;
+       ti,wakeup;
+};

drivers/extcon/Kconfig

@@ -53,4 +53,11 @@ config EXTCON_ARIZONA
 	  with Wolfson Arizona devices. These are audio CODECs with
 	  advanced audio accessory detection support.
 
+config EXTCON_PALMAS
+	tristate "Palmas USB EXTCON support"
+	depends on MFD_PALMAS
+	help
+	  Say Y here to enable support for USB peripheral and USB host
+	  detection by palmas usb.
+
 endif # MULTISTATE_SWITCH

drivers/extcon/Makefile

@@ -8,3 +8,4 @@ obj-$(CONFIG_EXTCON_ADC_JACK)	+= extcon-adc-jack.o
 obj-$(CONFIG_EXTCON_MAX77693)	+= extcon-max77693.o
 obj-$(CONFIG_EXTCON_MAX8997)	+= extcon-max8997.o
 obj-$(CONFIG_EXTCON_ARIZONA)	+= extcon-arizona.o
+obj-$(CONFIG_EXTCON_PALMAS)	+= extcon-palmas.o

drivers/extcon/extcon-palmas.c

@@ -0,0 +1,246 @@
+/*
+ * Palmas USB transceiver driver
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.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.
+ *
+ * Author: Graeme Gregory <gg@slimlogic.co.uk>
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ *
+ * Based on twl6030_usb.c
+ *
+ * Author: Hema HK <hemahk@ti.com>
+ *
+ * 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/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/mfd/palmas.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+
+static const char *palmas_extcon_cable[] = {
+	[0] = "USB",
+	[1] = "USB-HOST",
+	NULL,
+};
+
+static const int mutually_exclusive[] = {0x3, 0x0};
+
+static void palmas_usb_wakeup(struct palmas *palmas, int enable)
+{
+	if (enable)
+		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP,
+			PALMAS_USB_WAKEUP_ID_WK_UP_COMP);
+	else
+		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP, 0);
+}
+
+static irqreturn_t palmas_vbus_irq_handler(int irq, void *_palmas_usb)
+{
+	struct palmas_usb *palmas_usb = _palmas_usb;
+	unsigned int vbus_line_state;
+
+	palmas_read(palmas_usb->palmas, PALMAS_INTERRUPT_BASE,
+		PALMAS_INT3_LINE_STATE, &vbus_line_state);
+
+	if (vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS) {
+		if (palmas_usb->linkstat != PALMAS_USB_STATE_VBUS) {
+			palmas_usb->linkstat = PALMAS_USB_STATE_VBUS;
+			extcon_set_cable_state(&palmas_usb->edev, "USB", true);
+		} else {
+			dev_dbg(palmas_usb->dev,
+				"Spurious connect event detected\n");
+		}
+	} else if (!(vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS)) {
+		if (palmas_usb->linkstat == PALMAS_USB_STATE_VBUS) {
+			palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
+			extcon_set_cable_state(&palmas_usb->edev, "USB", false);
+		} else {
+			dev_dbg(palmas_usb->dev,
+				"Spurious disconnect event detected\n");
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
+{
+	unsigned int set;
+	struct palmas_usb *palmas_usb = _palmas_usb;
+
+	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+		PALMAS_USB_ID_INT_LATCH_SET, &set);
+
+	if (set & PALMAS_USB_ID_INT_SRC_ID_GND) {
+		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+			PALMAS_USB_ID_INT_EN_HI_SET,
+			PALMAS_USB_ID_INT_EN_HI_SET_ID_FLOAT);
+		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+			PALMAS_USB_ID_INT_EN_HI_CLR,
+			PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
+		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+			PALMAS_USB_ID_INT_LATCH_CLR,
+			PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
+		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
+		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", true);
+	} else if (set & PALMAS_USB_ID_INT_SRC_ID_FLOAT) {
+		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+			PALMAS_USB_ID_INT_EN_HI_SET,
+			PALMAS_USB_ID_INT_EN_HI_SET_ID_GND);
+		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+			PALMAS_USB_ID_INT_EN_HI_CLR,
+			PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
+		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+			PALMAS_USB_ID_INT_LATCH_CLR,
+			PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
+		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
+		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", false);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void palmas_enable_irq(struct palmas_usb *palmas_usb)
+{
+	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+		PALMAS_USB_VBUS_CTRL_SET,
+		PALMAS_USB_VBUS_CTRL_SET_VBUS_ACT_COMP);
+
+	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+		PALMAS_USB_ID_CTRL_SET, PALMAS_USB_ID_CTRL_SET_ID_ACT_COMP);
+
+	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+		PALMAS_USB_ID_INT_EN_HI_SET,
+		PALMAS_USB_ID_INT_EN_HI_SET_ID_GND);
+
+	palmas_vbus_irq_handler(palmas_usb->vbus_irq, palmas_usb);
+
+	/* cold plug for host mode needs this delay */
+	msleep(30);
+	palmas_id_irq_handler(palmas_usb->id_irq, palmas_usb);
+}
+
+static int palmas_usb_probe(struct platform_device *pdev)
+{
+	struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
+	struct palmas_usb_platform_data	*pdata = pdev->dev.platform_data;
+	struct device_node *node = pdev->dev.of_node;
+	struct palmas_usb *palmas_usb;
+	int status;
+
+	if (node && !pdata) {
+		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+
+		if (!pdata)
+			return -ENOMEM;
+
+		pdata->wakeup = of_property_read_bool(node, "ti,wakeup");
+	} else if (!pdata) {
+		return -EINVAL;
+	}
+
+	palmas_usb = devm_kzalloc(&pdev->dev, sizeof(*palmas_usb), GFP_KERNEL);
+	if (!palmas_usb)
+		return -ENOMEM;
+
+	palmas->usb = palmas_usb;
+	palmas_usb->palmas = palmas;
+
+	palmas_usb->dev	 = &pdev->dev;
+
+	palmas_usb->id_otg_irq = regmap_irq_get_virq(palmas->irq_data,
+						PALMAS_ID_OTG_IRQ);
+	palmas_usb->id_irq = regmap_irq_get_virq(palmas->irq_data,
+						PALMAS_ID_IRQ);
+	palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
+						PALMAS_VBUS_OTG_IRQ);
+	palmas_usb->vbus_irq = regmap_irq_get_virq(palmas->irq_data,
+						PALMAS_VBUS_IRQ);
+
+	palmas_usb_wakeup(palmas, pdata->wakeup);
+
+	platform_set_drvdata(pdev, palmas_usb);
+
+	palmas_usb->edev.name = "palmas-usb";
+	palmas_usb->edev.supported_cable = palmas_extcon_cable;
+	palmas_usb->edev.mutually_exclusive = mutually_exclusive;
+
+	status = extcon_dev_register(&palmas_usb->edev, palmas_usb->dev);
+	if (status) {
+		dev_err(&pdev->dev, "failed to register extcon device\n");
+		return status;
+	}
+
+	status = devm_request_threaded_irq(palmas_usb->dev, palmas_usb->id_irq,
+			NULL, palmas_id_irq_handler,
+			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
+			"palmas_usb_id", palmas_usb);
+	if (status < 0) {
+		dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
+					palmas_usb->id_irq, status);
+		goto fail_extcon;
+	}
+
+	status = devm_request_threaded_irq(palmas_usb->dev,
+			palmas_usb->vbus_irq, NULL, palmas_vbus_irq_handler,
+			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
+			"palmas_usb_vbus", palmas_usb);
+	if (status < 0) {
+		dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
+					palmas_usb->vbus_irq, status);
+		goto fail_extcon;
+	}
+
+	palmas_enable_irq(palmas_usb);
+
+	return 0;
+
+fail_extcon:
+	extcon_dev_unregister(&palmas_usb->edev);
+
+	return status;
+}
+
+static int palmas_usb_remove(struct platform_device *pdev)
+{
+	struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);
+
+	extcon_dev_unregister(&palmas_usb->edev);
+
+	return 0;
+}
+
+static struct of_device_id of_palmas_match_tbl[] = {
+	{ .compatible = "ti,palmas-usb", },
+	{ .compatible = "ti,twl6035-usb", },
+	{ /* end */ }
+};
+
+static struct platform_driver palmas_usb_driver = {
+	.probe = palmas_usb_probe,
+	.remove = palmas_usb_remove,
+	.driver = {
+		.name = "palmas-usb",
+		.of_match_table = of_palmas_match_tbl,
+		.owner = THIS_MODULE,
+	},
+};
+
+module_platform_driver(palmas_usb_driver);
+
+MODULE_ALIAS("platform:palmas-usb");
+MODULE_AUTHOR("Graeme Gregory <gg@slimlogic.co.uk>");
+MODULE_DESCRIPTION("Palmas USB transceiver driver");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(of, of_palmas_match_tbl);

include/linux/mfd/palmas.h

@@ -20,6 +20,8 @@
 #include <linux/leds.h>
 #include <linux/regmap.h>
 #include <linux/regulator/driver.h>
+#include <linux/extcon.h>
+#include <linux/usb/phy_companion.h>
 
 #define PALMAS_NUM_CLIENTS		3
 
@@ -37,6 +39,12 @@ struct palmas_gpadc;
 struct palmas_resource;
 struct palmas_usb;
 
+enum palmas_usb_state {
+	PALMAS_USB_STATE_DISCONNECT,
+	PALMAS_USB_STATE_VBUS,
+	PALMAS_USB_STATE_ID,
+};
+
 struct palmas {
 	struct device *dev;
 
@@ -180,9 +188,6 @@ struct palmas_pmic_platform_data {
 };
 
 struct palmas_usb_platform_data {
-	/* Set this if platform wishes its own vbus control */
-	int no_control_vbus;
-
 	/* Do we enable the wakeup comparator on probe */
 	int wakeup;
 };
@@ -350,22 +355,19 @@ struct palmas_usb {
 	struct palmas *palmas;
 	struct device *dev;
 
-	/* for vbus reporting with irqs disabled */
-	spinlock_t lock;
-
-	struct regulator *vbus_reg;
+	struct extcon_dev edev;
 
 	/* used to set vbus, in atomic path */
 	struct work_struct set_vbus_work;
 
-	int irq1;
-	int irq2;
-	int irq3;
-	int irq4;
+	int id_otg_irq;
+	int id_irq;
+	int vbus_otg_irq;
+	int vbus_irq;
 
 	int vbus_enable;
 
-	u8 linkstat;
+	enum palmas_usb_state linkstat;
 };
 
 #define comparator_to_palmas(x) container_of((x), struct palmas_usb, comparator)