[PATCH v4] extcon: Palmas Extcon Driver

[Kishon Vijay Abraham I]

From: Graeme Gregory <gg@xxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxx>
Signed-off-by: Moiz Sonasath <m-sonasath@xxxxxx>
Signed-off-by: Ruchika Kharwar <ruchika@xxxxxx>
Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
[kishon@xxxxxx: adapted palmas usb driver to use the extcon framework]
Signed-off-by: Sebastien Guiriec <s-guiriec@xxxxxx>
---
Changes from v3:
* adapted the driver to extcon framework (so moved to drivers/extcon)
* removed palmas_usb_(write/read) and replaced all calls with
  palmas_(read/write).
* ignored a checkpatch warning in the line 
	static const char *palmas_extcon_cable[] = {
  as it seemed to be incorrect?
* removed all references to OMAP in this driver.
* couldn't test this driver with mainline as omap5 panda is not booting
  with mainline.
* A comment to change to platform_get_irq from regmap is not done as I felt
  the data should come from regmap in this case. Graeme?
Changes from v2:
* Moved the driver to drivers/usb/phy/
* Added a bit more explanation in Kconfig
 .../devicetree/bindings/extcon/extcon-twl.txt      |   17 +
 drivers/extcon/Kconfig                             |    7 +
 drivers/extcon/Makefile                            |    1 +
 drivers/extcon/extcon-palmas.c                     |  389 ++++++++++++++++++++
 include/linux/extcon/extcon_palmas.h               |   26 ++
 include/linux/mfd/palmas.h                         |    8 +-
 6 files changed, 447 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/extcon/extcon-twl.txt
 create mode 100644 drivers/extcon/extcon-palmas.c
 create mode 100644 include/linux/extcon/extcon_palmas.h

diff --git a/Documentation/devicetree/bindings/extcon/extcon-twl.txt b/Documentation/devicetree/bindings/extcon/extcon-twl.txt
new file mode 100644
index 0000000..a7f6527
--- /dev/null
+++ b/Documentation/devicetree/bindings/extcon/extcon-twl.txt
@@ -0,0 +1,17 @@
+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
+ - ti,no_control_vbus: if the platform wishes its own vbus control
+
+palmas-usb {
+       compatible = "ti,twl6035-usb", "ti,palmas-usb";
+       vbus-supply = <&smps10_reg>;
+       ti,wakeup;
+};
+
diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index 5168a13..c881899 100644
--- a/drivers/extcon/Kconfig
+++ b/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
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index f98a3c4..540e2c3 100644
--- a/drivers/extcon/Makefile
+++ b/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
diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
new file mode 100644
index 0000000..3ef042f
--- /dev/null
+++ b/drivers/extcon/extcon-palmas.c
@@ -0,0 +1,389 @@
+/*
+ * 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@...mlogic.co.uk>
+ * Author: Kishon Vijay Abraham I <kishon@...com>
+ *
+ * Based on twl6030_usb.c
+ *
+ * Author: Hema HK <hemahk@...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/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/usb/phy_companion.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
+#include <linux/notifier.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/mfd/palmas.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/extcon/extcon_palmas.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 ssize_t palmas_usb_vbus_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	unsigned long		flags;
+	int			ret = -EINVAL;
+	struct palmas_usb	*palmas_usb = dev_get_drvdata(dev);
+
+	spin_lock_irqsave(&palmas_usb->lock, flags);
+
+	switch (palmas_usb->linkstat) {
+	case PALMAS_USB_STATE_VBUS:
+	       ret = snprintf(buf, PAGE_SIZE, "vbus\n");
+	       break;
+	case PALMAS_USB_STATE_ID:
+	       ret = snprintf(buf, PAGE_SIZE, "id\n");
+	       break;
+	case PALMAS_USB_STATE_DISCONNECT:
+	       ret = snprintf(buf, PAGE_SIZE, "none\n");
+	       break;
+	default:
+	       ret = snprintf(buf, PAGE_SIZE, "UNKNOWN\n");
+	}
+	spin_unlock_irqrestore(&palmas_usb->lock, flags);
+
+	return ret;
+}
+static DEVICE_ATTR(vbus, 0444, palmas_usb_vbus_show, NULL);
+
+static irqreturn_t palmas_vbus_wakeup_irq(int irq, void *_palmas_usb)
+{
+	int ret;
+	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) {
+			if (palmas_usb->vbus_reg) {
+				ret = regulator_enable(palmas_usb->vbus_reg);
+				if (ret) {
+					dev_dbg(palmas_usb->dev,
+						"regulator enable failed\n");
+					goto ret0;
+				}
+			}
+			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) {
+			if (palmas_usb->vbus_reg)
+				regulator_disable(palmas_usb->vbus_reg);
+			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");
+		}
+	}
+
+ret0:
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t palmas_id_wakeup_irq(int irq, void *_palmas_usb)
+{
+	int			ret;
+	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) {
+		if (palmas_usb->vbus_reg) {
+			ret = regulator_enable(palmas_usb->vbus_reg);
+			if (ret) {
+				dev_dbg(palmas_usb->dev,
+					"regulator enable failed\n");
+				goto ret0;
+			}
+		}
+		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_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);
+		if (palmas_usb->vbus_reg)
+			regulator_disable(palmas_usb->vbus_reg);
+		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
+		extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", false);
+	}
+
+ret0:
+	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_wakeup_irq(palmas_usb->irq4, palmas_usb);
+	palmas_id_wakeup_irq(palmas_usb->irq2, palmas_usb);
+}
+
+static void palmas_set_vbus_work(struct work_struct *data)
+{
+	int ret;
+	struct palmas_usb *palmas_usb = container_of(data, struct palmas_usb,
+								set_vbus_work);
+
+	if (IS_ERR_OR_NULL(palmas_usb->vbus_reg)) {
+		dev_err(palmas_usb->dev, "invalid regulator\n");
+		return;
+	}
+
+	/*
+	 * Start driving VBUS. Set OPA_MODE bit in CHARGERUSB_CTRL1
+	 * register. This enables boost mode.
+	 */
+
+	if (palmas_usb->vbus_enable) {
+		ret = regulator_enable(palmas_usb->vbus_reg);
+		if (ret)
+			dev_dbg(palmas_usb->dev, "regulator enable failed\n");
+	} else {
+		regulator_disable(palmas_usb->vbus_reg);
+	}
+}
+
+static int palmas_set_vbus(struct phy_companion *comparator, bool enabled)
+{
+	struct palmas_usb *palmas_usb = comparator_to_palmas(comparator);
+
+	palmas_usb->vbus_enable = enabled;
+	schedule_work(&palmas_usb->set_vbus_work);
+
+	return 0;
+}
+
+static int palmas_start_srp(struct phy_companion *comparator)
+{
+	struct palmas_usb *palmas_usb = comparator_to_palmas(comparator);
+
+	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+		PALMAS_USB_VBUS_CTRL_SET, PALMAS_USB_VBUS_CTRL_SET_VBUS_DISCHRG
+		| PALMAS_USB_VBUS_CTRL_SET_VBUS_IADP_SINK);
+	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+		PALMAS_USB_VBUS_CTRL_SET,
+		PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS |
+		PALMAS_USB_VBUS_CTRL_SET_VBUS_IADP_SINK);
+
+	mdelay(100);
+
+	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+		PALMAS_USB_VBUS_CTRL_CLR,
+		PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS |
+		PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS);
+
+	return 0;
+}
+
+static void palmas_dt_to_pdata(struct device_node *node,
+		struct palmas_usb_platform_data *pdata)
+{
+	pdata->no_control_vbus = of_property_read_bool(node,
+					"ti,no_control_vbus");
+	pdata->wakeup = of_property_read_bool(node, "ti,wakeup");
+}
+
+static int palmas_usb_probe(struct platform_device *pdev)
+{
+	u32 ret;
+	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;
+
+		palmas_dt_to_pdata(node, pdata);
+	}
+
+	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->irq1 = regmap_irq_get_virq(palmas->irq_data,
+						PALMAS_ID_OTG_IRQ);
+	palmas_usb->irq2 = regmap_irq_get_virq(palmas->irq_data,
+						PALMAS_ID_IRQ);
+	palmas_usb->irq3 = regmap_irq_get_virq(palmas->irq_data,
+						PALMAS_VBUS_OTG_IRQ);
+	palmas_usb->irq4 = regmap_irq_get_virq(palmas->irq_data,
+						PALMAS_VBUS_IRQ);
+
+	palmas_usb->comparator.set_vbus	= palmas_set_vbus;
+	palmas_usb->comparator.start_srp = palmas_start_srp;
+
+	palmas_usb_wakeup(palmas, pdata->wakeup);
+
+	/* init spinlock for workqueue */
+	spin_lock_init(&palmas_usb->lock);
+
+	if (!pdata->no_control_vbus) {
+		palmas_usb->vbus_reg = devm_regulator_get(&pdev->dev, "vbus");
+		if (IS_ERR(palmas_usb->vbus_reg)) {
+			dev_err(&pdev->dev, "vbus init failed\n");
+			return PTR_ERR(palmas_usb->vbus_reg);
+		}
+	}
+
+	platform_set_drvdata(pdev, palmas_usb);
+
+	if (device_create_file(&pdev->dev, &dev_attr_vbus))
+		dev_warn(&pdev->dev, "could not create sysfs file\n");
+
+	palmas_usb->edev.name = "palmas_usb";
+	palmas_usb->edev.supported_cable = palmas_extcon_cable;
+	palmas_usb->edev.mutually_exclusive = mutually_exclusive;
+
+	ret = extcon_dev_register(&palmas_usb->edev, palmas_usb->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register extcon device\n");
+		return ret;
+	}
+
+	/* init spinlock for workqueue */
+	spin_lock_init(&palmas_usb->lock);
+
+	INIT_WORK(&palmas_usb->set_vbus_work, palmas_set_vbus_work);
+
+	status = devm_request_threaded_irq(palmas_usb->dev, palmas_usb->irq2,
+			NULL, palmas_id_wakeup_irq,
+			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
+			"palmas_usb", palmas_usb);
+	if (status < 0) {
+		dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
+					palmas_usb->irq2, status);
+		goto fail_irq;
+	}
+
+	status = devm_request_threaded_irq(palmas_usb->dev, palmas_usb->irq4,
+			NULL, palmas_vbus_wakeup_irq,
+			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
+			"palmas_usb", palmas_usb);
+	if (status < 0) {
+		dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
+					palmas_usb->irq4, status);
+		goto fail_irq;
+	}
+
+	palmas_enable_irq(palmas_usb);
+
+	return 0;
+
+fail_irq:
+	cancel_work_sync(&palmas_usb->set_vbus_work);
+	device_remove_file(palmas_usb->dev, &dev_attr_vbus);
+
+	return status;
+}
+
+static int palmas_usb_remove(struct platform_device *pdev)
+{
+	struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);
+
+	device_remove_file(palmas_usb->dev, &dev_attr_vbus);
+	cancel_work_sync(&palmas_usb->set_vbus_work);
+	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@...mlogic.co.uk>");
+MODULE_DESCRIPTION("Palmas USB transceiver driver");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(of, of_palmas_match_tbl);
diff --git a/include/linux/extcon/extcon_palmas.h b/include/linux/extcon/extcon_palmas.h
new file mode 100644
index 0000000..a5119c9
--- /dev/null
+++ b/include/linux/extcon/extcon_palmas.h
@@ -0,0 +1,26 @@
+/*
+ * extcon_palmas.h - palmas extcon driver to detect VBUS or ID events
+ *
+ * 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: Kishon Vijay Abraham I <kishon@xxxxxx>
+ *
+ * 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.
+ *
+ */
+
+#ifndef __EXTCON_PALMAS_H__
+#define __EXTCON_PALMAS_H__
+
+#define	PALMAS_USB_STATE_DISCONNECT	0x0
+#define	PALMAS_USB_STATE_VBUS		BIT(0)
+#define	PALMAS_USB_STATE_ID		BIT(1)
+
+#endif	/* __EXTCON_PALMAS_H__ */
diff --git a/include/linux/mfd/palmas.h b/include/linux/mfd/palmas.h
index 8f21daf..d671679 100644
--- a/include/linux/mfd/palmas.h
+++ b/include/linux/mfd/palmas.h
@@ -18,8 +18,10 @@
 
 #include <linux/usb/otg.h>
 #include <linux/leds.h>
+#include <linux/extcon.h>
 #include <linux/regmap.h>
 #include <linux/regulator/driver.h>
+#include <linux/usb/phy_companion.h>
 
 #define PALMAS_NUM_CLIENTS		3
 
@@ -349,6 +351,9 @@ struct palmas_resource {
 struct palmas_usb {
 	struct palmas *palmas;
 	struct device *dev;
+	struct extcon_dev edev;
+
+	struct phy_companion comparator;
 
 	/* for vbus reporting with irqs disabled */
 	spinlock_t lock;
@@ -365,7 +370,8 @@ struct palmas_usb {
 
 	int vbus_enable;
 
-	u8 linkstat;
+	int mailboxstat;
+	int linkstat;
 };
 
 #define comparator_to_palmas(x) container_of((x), struct palmas_usb, comparator)
-- 
1.7.10.4

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