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