[PATCH] extcon: extcon-dra7xx: Add Extcon driver for DRA7xx
From: George Cherian
Date: Sun Jun 15 2014 - 22:45:26 EST
This is the driver for the USB ID pin detection. This driver
handles only the USB ID pin changes generated by cable
insertion/removal.
Signed-off-by: George Cherian <george.cherian@xxxxxx>
---
.../devicetree/bindings/extcon/extcon-dra7xx.txt | 15 ++
drivers/extcon/Kconfig | 5 +
drivers/extcon/Makefile | 1 +
drivers/extcon/extcon-dra7xx.c | 164 +++++++++++++++++++++
4 files changed, 185 insertions(+)
create mode 100644 Documentation/devicetree/bindings/extcon/extcon-dra7xx.txt
create mode 100644 drivers/extcon/extcon-dra7xx.c
diff --git a/Documentation/devicetree/bindings/extcon/extcon-dra7xx.txt b/Documentation/devicetree/bindings/extcon/extcon-dra7xx.txt
new file mode 100644
index 0000000..69c3804
--- /dev/null
+++ b/Documentation/devicetree/bindings/extcon/extcon-dra7xx.txt
@@ -0,0 +1,15 @@
+EXTCON FOR DRA7xx USB
+
+Required Properties:
+ - compatible : Should be "ti,dra7xx-extcon"
+ - gpios : specifies the gpio pin used for ID pin detection.
+
+
+Please refer to ../gpio/gpio.txt for details of the common GPIO bindings
+
+Example:
+
+ dra7xx_extcon {
+ compatible = "ti,dra7xx-extcon";
+ gpios = <&gpio21 1 0>;
+ };
diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index aebde48..1481b7f 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -70,4 +70,9 @@ config EXTCON_PALMAS
Say Y here to enable support for USB peripheral and USB host
detection by palmas usb.
+config EXTCON_DRA7XX
+ tristate "DRA7xx USB ID detection EXTCON support"
+ help
+ Say Y here to enable support for USB ID detection for DRA7xx.
+
endif # MULTISTATE_SWITCH
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index bf7861e..b5f7cac 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -10,3 +10,4 @@ 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
+obj-$(CONFIG_EXTCON_DRA7XX) += extcon-dra7xx.o
diff --git a/drivers/extcon/extcon-dra7xx.c b/drivers/extcon/extcon-dra7xx.c
new file mode 100644
index 0000000..2f80509
--- /dev/null
+++ b/drivers/extcon/extcon-dra7xx.c
@@ -0,0 +1,164 @@
+/*
+ * DRA7xx-Extcon USB ID pin detection driver
+ *
+ * Copyright (C) 2014 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: George Cherian <george.cherian@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.
+ */
+
+#include <linux/err.h>
+#include <linux/extcon.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+struct dra7xx_extcon {
+ struct device *dev;
+ struct extcon_dev edev;
+
+ int id_gpio;
+ int id_irq;
+};
+
+static const char *dra7xx_extcon_cable[] = {
+ [1] = "USB-HOST",
+ NULL,
+};
+
+#define ID_GND 0
+
+static irqreturn_t id_irq_handler(int irq, void *data)
+{
+ struct dra7xx_extcon *dra7xx_extcon = (struct dra7xx_extcon *)data;
+ int id_current;
+
+ id_current = gpio_get_value_cansleep(dra7xx_extcon->id_gpio);
+ if (id_current == ID_GND)
+ extcon_set_cable_state(&dra7xx_extcon->edev, "USB-HOST", true);
+ else
+ extcon_set_cable_state(&dra7xx_extcon->edev, "USB-HOST", false);
+
+ return IRQ_HANDLED;
+}
+
+static void dra7xx_extcon_set_initial_state(struct dra7xx_extcon *dra7xx_extcon)
+{
+ int id_current;
+
+ id_current = gpio_get_value_cansleep(dra7xx_extcon->id_gpio);
+ if (id_current == ID_GND)
+ extcon_set_cable_state(&dra7xx_extcon->edev,
+ "USB-HOST", true);
+ else
+ extcon_set_cable_state(&dra7xx_extcon->edev,
+ "USB-HOST", false);
+}
+
+static int dra7xx_extcon_request_irq(struct dra7xx_extcon *dra7xx_extcon)
+{
+ int ret;
+
+ ret = devm_request_threaded_irq(dra7xx_extcon->dev,
+ dra7xx_extcon->id_irq,
+ NULL, id_irq_handler,
+ IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
+ dev_name(dra7xx_extcon->dev),
+ (void *)dra7xx_extcon);
+ if (ret) {
+ dev_err(dra7xx_extcon->dev, "failed to request id irq #%d\n",
+ dra7xx_extcon->id_irq);
+ return ret;
+ }
+ return ret;
+}
+
+static int dra7xx_extcon_probe(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct dra7xx_extcon *dra7xx_extcon;
+ int ret, gpio;
+
+ dra7xx_extcon = devm_kzalloc(&pdev->dev, sizeof(*dra7xx_extcon),
+ GFP_KERNEL);
+ if (!dra7xx_extcon)
+ return -ENOMEM;
+
+ dra7xx_extcon->dev = &pdev->dev;
+
+ platform_set_drvdata(pdev, dra7xx_extcon);
+
+ dra7xx_extcon->edev.supported_cable = dra7xx_extcon_cable;
+
+ gpio = of_get_gpio(node, 0);
+ if (gpio_is_valid(gpio)) {
+ dra7xx_extcon->id_gpio = gpio;
+ ret = devm_gpio_request(&pdev->dev, dra7xx_extcon->id_gpio,
+ "id_gpio");
+ if (ret)
+ return ret;
+
+ dra7xx_extcon->id_irq = gpio_to_irq(dra7xx_extcon->id_gpio);
+ } else {
+ dev_err(&pdev->dev, "failed to get id gpio\n");
+ return -EPROBE_DEFER;
+ }
+
+ ret = dra7xx_extcon_request_irq(dra7xx_extcon);
+ if (ret)
+ return ret;
+
+ ret = extcon_dev_register(&dra7xx_extcon->edev);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register extcon device\n");
+ return ret;
+ }
+
+ dra7xx_extcon_set_initial_state(dra7xx_extcon);
+
+ return 0;
+}
+
+static int dra7xx_extcon_remove(struct platform_device *pdev)
+{
+ struct dra7xx_extcon *dra7xx_extcon = platform_get_drvdata(pdev);
+
+ extcon_dev_unregister(&dra7xx_extcon->edev);
+ return 0;
+}
+
+static struct of_device_id of_dra7xx_extcon_match_tbl[] = {
+ { .compatible = "ti,dra7xx-extcon", },
+ { /* end */ }
+};
+
+static struct platform_driver dra7xx_extcon_driver = {
+ .probe = dra7xx_extcon_probe,
+ .remove = dra7xx_extcon_remove,
+ .driver = {
+ .name = "dra7xx-extcon",
+ .of_match_table = of_dra7xx_extcon_match_tbl,
+ .owner = THIS_MODULE,
+ },
+};
+
+module_platform_driver(dra7xx_extcon_driver);
+
+MODULE_ALIAS("platform:extcon-dra7xx");
+MODULE_AUTHOR("George Cherian <george.cherian@xxxxxx>");
+MODULE_DESCRIPTION("USB ID pin detection driver for DRA7xx");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(of, of_dra7xx_extcon_match_tbl);
--
1.8.3.1
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