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