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![Michael Auchter](/assets/img/avatar_default.png)
This patch adds an extcon driver for the TI TUSB320 USB Type-C device. This can be used to detect whether the port is configured as a downstream or upstream facing port. Signed-off-by: Michael Auchter <michael.auchter@ni.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
184 lines
4.7 KiB
C
184 lines
4.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/**
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* drivers/extcon/extcon-tusb320.c - TUSB320 extcon driver
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*
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* Copyright (C) 2020 National Instruments Corporation
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* Author: Michael Auchter <michael.auchter@ni.com>
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*/
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#include <linux/extcon-provider.h>
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#include <linux/i2c.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/regmap.h>
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#define TUSB320_REG9 0x9
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#define TUSB320_REG9_ATTACHED_STATE_SHIFT 6
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#define TUSB320_REG9_ATTACHED_STATE_MASK 0x3
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#define TUSB320_REG9_CABLE_DIRECTION BIT(5)
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#define TUSB320_REG9_INTERRUPT_STATUS BIT(4)
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#define TUSB320_ATTACHED_STATE_NONE 0x0
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#define TUSB320_ATTACHED_STATE_DFP 0x1
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#define TUSB320_ATTACHED_STATE_UFP 0x2
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#define TUSB320_ATTACHED_STATE_ACC 0x3
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struct tusb320_priv {
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struct device *dev;
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struct regmap *regmap;
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struct extcon_dev *edev;
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};
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static const char * const tusb_attached_states[] = {
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[TUSB320_ATTACHED_STATE_NONE] = "not attached",
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[TUSB320_ATTACHED_STATE_DFP] = "downstream facing port",
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[TUSB320_ATTACHED_STATE_UFP] = "upstream facing port",
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[TUSB320_ATTACHED_STATE_ACC] = "accessory",
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};
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static const unsigned int tusb320_extcon_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 int tusb320_check_signature(struct tusb320_priv *priv)
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{
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static const char sig[] = { '\0', 'T', 'U', 'S', 'B', '3', '2', '0' };
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unsigned val;
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int i, ret;
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for (i = 0; i < sizeof(sig); i++) {
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ret = regmap_read(priv->regmap, sizeof(sig) - 1 - i, &val);
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if (ret < 0)
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return ret;
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if (val != sig[i]) {
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dev_err(priv->dev, "signature mismatch!\n");
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return -ENODEV;
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}
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}
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return 0;
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}
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static irqreturn_t tusb320_irq_handler(int irq, void *dev_id)
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{
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struct tusb320_priv *priv = dev_id;
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int state, polarity;
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unsigned reg;
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if (regmap_read(priv->regmap, TUSB320_REG9, ®)) {
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dev_err(priv->dev, "error during i2c read!\n");
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return IRQ_NONE;
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}
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if (!(reg & TUSB320_REG9_INTERRUPT_STATUS))
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return IRQ_NONE;
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state = (reg >> TUSB320_REG9_ATTACHED_STATE_SHIFT) &
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TUSB320_REG9_ATTACHED_STATE_MASK;
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polarity = !!(reg & TUSB320_REG9_CABLE_DIRECTION);
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dev_dbg(priv->dev, "attached state: %s, polarity: %d\n",
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tusb_attached_states[state], polarity);
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extcon_set_state(priv->edev, EXTCON_USB,
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state == TUSB320_ATTACHED_STATE_UFP);
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extcon_set_state(priv->edev, EXTCON_USB_HOST,
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state == TUSB320_ATTACHED_STATE_DFP);
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extcon_set_property(priv->edev, EXTCON_USB,
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EXTCON_PROP_USB_TYPEC_POLARITY,
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(union extcon_property_value)polarity);
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extcon_set_property(priv->edev, EXTCON_USB_HOST,
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EXTCON_PROP_USB_TYPEC_POLARITY,
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(union extcon_property_value)polarity);
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extcon_sync(priv->edev, EXTCON_USB);
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extcon_sync(priv->edev, EXTCON_USB_HOST);
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regmap_write(priv->regmap, TUSB320_REG9, reg);
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return IRQ_HANDLED;
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}
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static const struct regmap_config tusb320_regmap_config = {
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.reg_bits = 8,
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.val_bits = 8,
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};
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static int tusb320_extcon_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct tusb320_priv *priv;
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int ret;
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priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->dev = &client->dev;
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priv->regmap = devm_regmap_init_i2c(client, &tusb320_regmap_config);
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if (IS_ERR(priv->regmap))
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return PTR_ERR(priv->regmap);
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ret = tusb320_check_signature(priv);
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if (ret)
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return ret;
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priv->edev = devm_extcon_dev_allocate(priv->dev, tusb320_extcon_cable);
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if (IS_ERR(priv->edev)) {
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dev_err(priv->dev, "failed to allocate extcon device\n");
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return PTR_ERR(priv->edev);
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}
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ret = devm_extcon_dev_register(priv->dev, priv->edev);
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if (ret < 0) {
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dev_err(priv->dev, "failed to register extcon device\n");
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return ret;
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}
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extcon_set_property_capability(priv->edev, EXTCON_USB,
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EXTCON_PROP_USB_TYPEC_POLARITY);
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extcon_set_property_capability(priv->edev, EXTCON_USB_HOST,
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EXTCON_PROP_USB_TYPEC_POLARITY);
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/* update initial state */
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tusb320_irq_handler(client->irq, priv);
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ret = devm_request_threaded_irq(priv->dev, client->irq, NULL,
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tusb320_irq_handler,
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IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
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client->name, priv);
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return ret;
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}
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static const struct of_device_id tusb320_extcon_dt_match[] = {
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{ .compatible = "ti,tusb320", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, tusb320_extcon_dt_match);
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static struct i2c_driver tusb320_extcon_driver = {
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.probe = tusb320_extcon_probe,
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.driver = {
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.name = "extcon-tusb320",
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.of_match_table = tusb320_extcon_dt_match,
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},
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};
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static int __init tusb320_init(void)
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{
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return i2c_add_driver(&tusb320_extcon_driver);
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}
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subsys_initcall(tusb320_init);
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static void __exit tusb320_exit(void)
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{
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i2c_del_driver(&tusb320_extcon_driver);
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}
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module_exit(tusb320_exit);
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MODULE_AUTHOR("Michael Auchter <michael.auchter@ni.com>");
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MODULE_DESCRIPTION("TI TUSB320 extcon driver");
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MODULE_LICENSE("GPL v2");
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