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path: root/drivers/extcon/extcon-max3355.c
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Diffstat (limited to 'drivers/extcon/extcon-max3355.c')
-rw-r--r--drivers/extcon/extcon-max3355.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/extcon/extcon-max3355.c b/drivers/extcon/extcon-max3355.c
new file mode 100644
index 000000000000..c24abec5d06c
--- /dev/null
+++ b/drivers/extcon/extcon-max3355.c
@@ -0,0 +1,146 @@
+/*
+ * Maxim Integrated MAX3355 USB OTG chip extcon driver
+ *
+ * Copyright (C) 2014-2015 Cogent Embedded, Inc.
+ * Author: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ */
+
+#include <linux/extcon.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+struct max3355_data {
+ struct extcon_dev *edev;
+ struct gpio_desc *id_gpiod;
+ struct gpio_desc *shdn_gpiod;
+};
+
+static const unsigned int max3355_cable[] = {
+ EXTCON_USB,
+ EXTCON_USB_HOST,
+ EXTCON_NONE,
+};
+
+static irqreturn_t max3355_id_irq(int irq, void *dev_id)
+{
+ struct max3355_data *data = dev_id;
+ int id = gpiod_get_value_cansleep(data->id_gpiod);
+
+ if (id) {
+ /*
+ * ID = 1 means USB HOST cable detached.
+ * As we don't have event for USB peripheral cable attached,
+ * we simulate USB peripheral attach here.
+ */
+ extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, false);
+ extcon_set_cable_state_(data->edev, EXTCON_USB, true);
+ } else {
+ /*
+ * ID = 0 means USB HOST cable attached.
+ * As we don't have event for USB peripheral cable detached,
+ * we simulate USB peripheral detach here.
+ */
+ extcon_set_cable_state_(data->edev, EXTCON_USB, false);
+ extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, true);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int max3355_probe(struct platform_device *pdev)
+{
+ struct max3355_data *data;
+ struct gpio_desc *gpiod;
+ int irq, err;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
+ GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
+ if (IS_ERR(gpiod)) {
+ dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");
+ return PTR_ERR(gpiod);
+ }
+ data->id_gpiod = gpiod;
+
+ gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH);
+ if (IS_ERR(gpiod)) {
+ dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");
+ return PTR_ERR(gpiod);
+ }
+ data->shdn_gpiod = gpiod;
+
+ data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);
+ if (IS_ERR(data->edev)) {
+ dev_err(&pdev->dev, "failed to allocate extcon device\n");
+ return PTR_ERR(data->edev);
+ }
+
+ err = devm_extcon_dev_register(&pdev->dev, data->edev);
+ if (err < 0) {
+ dev_err(&pdev->dev, "failed to register extcon device\n");
+ return err;
+ }
+
+ irq = gpiod_to_irq(data->id_gpiod);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n");
+ return irq;
+ }
+
+ err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq,
+ IRQF_ONESHOT | IRQF_NO_SUSPEND |
+ IRQF_TRIGGER_RISING |
+ IRQF_TRIGGER_FALLING,
+ pdev->name, data);
+ if (err < 0) {
+ dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n");
+ return err;
+ }
+
+ platform_set_drvdata(pdev, data);
+
+ /* Perform initial detection */
+ max3355_id_irq(irq, data);
+
+ return 0;
+}
+
+static int max3355_remove(struct platform_device *pdev)
+{
+ struct max3355_data *data = platform_get_drvdata(pdev);
+
+ gpiod_set_value_cansleep(data->shdn_gpiod, 0);
+
+ return 0;
+}
+
+static const struct of_device_id max3355_match_table[] = {
+ { .compatible = "maxim,max3355", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, max3355_match_table);
+
+static struct platform_driver max3355_driver = {
+ .probe = max3355_probe,
+ .remove = max3355_remove,
+ .driver = {
+ .name = "extcon-max3355",
+ .of_match_table = max3355_match_table,
+ },
+};
+
+module_platform_driver(max3355_driver);
+
+MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
+MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
+MODULE_LICENSE("GPL v2");