linux-stable/drivers/extcon/extcon-usbc-tusb320.c
Yassine Oudjana 70c55d6be6 extcon: usbc-tusb320: Add support for mode setting and reset
Reset the chip and set its mode to default (maintain mode set by PORT pin)
during probe to make sure it comes up in the default state.

Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-10-27 14:13:38 +09:00

261 lines
6.4 KiB
C

// 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_REGA 0xa
#define TUSB320_REGA_I2C_SOFT_RESET BIT(3)
#define TUSB320_REGA_MODE_SELECT_SHIFT 4
#define TUSB320_REGA_MODE_SELECT_MASK 0x3
enum tusb320_attached_state {
TUSB320_ATTACHED_STATE_NONE,
TUSB320_ATTACHED_STATE_DFP,
TUSB320_ATTACHED_STATE_UFP,
TUSB320_ATTACHED_STATE_ACC,
};
enum tusb320_mode {
TUSB320_MODE_PORT,
TUSB320_MODE_UFP,
TUSB320_MODE_DFP,
TUSB320_MODE_DRP,
};
struct tusb320_priv {
struct device *dev;
struct regmap *regmap;
struct extcon_dev *edev;
enum tusb320_attached_state state;
};
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 int tusb320_set_mode(struct tusb320_priv *priv, enum tusb320_mode mode)
{
int ret;
/* Mode cannot be changed while cable is attached */
if (priv->state != TUSB320_ATTACHED_STATE_NONE)
return -EBUSY;
/* Write mode */
ret = regmap_write_bits(priv->regmap, TUSB320_REGA,
TUSB320_REGA_MODE_SELECT_MASK << TUSB320_REGA_MODE_SELECT_SHIFT,
mode << TUSB320_REGA_MODE_SELECT_SHIFT);
if (ret) {
dev_err(priv->dev, "failed to write mode: %d\n", ret);
return ret;
}
return 0;
}
static int tusb320_reset(struct tusb320_priv *priv)
{
int ret;
/* Set mode to default (follow PORT pin) */
ret = tusb320_set_mode(priv, TUSB320_MODE_PORT);
if (ret && ret != -EBUSY) {
dev_err(priv->dev,
"failed to set mode to PORT: %d\n", ret);
return ret;
}
/* Perform soft reset */
ret = regmap_write_bits(priv->regmap, TUSB320_REGA,
TUSB320_REGA_I2C_SOFT_RESET, 1);
if (ret) {
dev_err(priv->dev,
"failed to write soft reset bit: %d\n", ret);
return ret;
}
/* Wait for chip to go through reset */
msleep(95);
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, &reg)) {
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);
priv->state = state;
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);
/* Reset chip to its default state */
ret = tusb320_reset(priv);
if (ret)
dev_warn(priv->dev, "failed to reset chip: %d\n", ret);
else
/*
* State and polarity might change after a reset, so update
* them again and make sure the interrupt status bit is cleared.
*/
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");