linux/drivers/extcon/extcon-usbc-tusb320.c
Yassine Oudjana ce0320bd38 extcon: usbc-tusb320: Add support for TUSB320L
TUSB320L is a newer chip with additional features, and it has additional steps
in its mode changing sequence:
 - Disable CC state machine,
 - Write to mode register,
 - Wait for 5 ms,
 - Re-enable CC state machine.
It also has an additional register that a revision number can be read from.

Add support for the mode changing sequence, and read the revision number during
probe and print it as info.

Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2021-10-27 14:13:39 +09:00

338 lines
8.3 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 TUSB320L_REGA_DISABLE_TERM BIT(0)
#define TUSB320_REGA_I2C_SOFT_RESET BIT(3)
#define TUSB320_REGA_MODE_SELECT_SHIFT 4
#define TUSB320_REGA_MODE_SELECT_MASK 0x3
#define TUSB320L_REGA0_REVISION 0xa0
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 tusb320_ops {
int (*set_mode)(struct tusb320_priv *priv, enum tusb320_mode mode);
int (*get_revision)(struct tusb320_priv *priv, unsigned int *revision);
};
struct tusb320_priv {
struct device *dev;
struct regmap *regmap;
struct extcon_dev *edev;
struct tusb320_ops *ops;
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 tusb320l_set_mode(struct tusb320_priv *priv, enum tusb320_mode mode)
{
int ret;
/* Disable CC state machine */
ret = regmap_write_bits(priv->regmap, TUSB320_REGA,
TUSB320L_REGA_DISABLE_TERM, 1);
if (ret) {
dev_err(priv->dev,
"failed to disable CC state machine: %d\n", ret);
return ret;
}
/* 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);
goto err;
}
msleep(5);
err:
/* Re-enable CC state machine */
ret = regmap_write_bits(priv->regmap, TUSB320_REGA,
TUSB320L_REGA_DISABLE_TERM, 0);
if (ret)
dev_err(priv->dev,
"failed to re-enable CC state machine: %d\n", ret);
return ret;
}
static int tusb320_reset(struct tusb320_priv *priv)
{
int ret;
/* Set mode to default (follow PORT pin) */
ret = priv->ops->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 int tusb320l_get_revision(struct tusb320_priv *priv, unsigned int *revision)
{
return regmap_read(priv->regmap, TUSB320L_REGA0_REVISION, revision);
}
static struct tusb320_ops tusb320_ops = {
.set_mode = tusb320_set_mode,
};
static struct tusb320_ops tusb320l_ops = {
.set_mode = tusb320l_set_mode,
.get_revision = tusb320l_get_revision,
};
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;
const void *match_data;
unsigned int revision;
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;
match_data = device_get_match_data(&client->dev);
if (!match_data)
return -EINVAL;
priv->ops = (struct tusb320_ops*)match_data;
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);
}
if (priv->ops->get_revision) {
ret = priv->ops->get_revision(priv, &revision);
if (ret)
dev_warn(priv->dev,
"failed to read revision register: %d\n", ret);
else
dev_info(priv->dev, "chip revision %d\n", revision);
}
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", .data = &tusb320_ops, },
{ .compatible = "ti,tusb320l", .data = &tusb320l_ops, },
{ }
};
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");