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SubjectRe: [PATCH v2 1/2] extcon: add driver for TI TUSB320
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Hi,

Looks good to me. I add some comment. Please check them.

On 10/12/20 11:47 PM, Michael Auchter wrote:
> 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>
> ---
> Changes since v1:
> - Drop license text that's redundant with SPDX tag
> - Cleanup, sort list of includes
> - Add additional register defines
> - Switch to use regmap API
> - Fix Kconfig to depend on I2C, not GPIOLIB
>
> drivers/extcon/Kconfig | 8 ++
> drivers/extcon/Makefile | 1 +
> drivers/extcon/extcon-usbc-tusb320.c | 191 +++++++++++++++++++++++++++
> 3 files changed, 200 insertions(+)
> create mode 100644 drivers/extcon/extcon-usbc-tusb320.c
>
> diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
> index aac507bff135..af58ebca2bf6 100644
> --- a/drivers/extcon/Kconfig
> +++ b/drivers/extcon/Kconfig
> @@ -186,4 +186,12 @@ config EXTCON_USBC_CROS_EC
> Say Y here to enable USB Type C cable detection extcon support when
> using Chrome OS EC based USB Type-C ports.
>
> +config EXTCON_USBC_TUSB320
> + tristate "TI TUSB320 USB-C extcon support"
> + depends on I2C
> + select REGMAP_I2C
> + help
> + Say Y here to enable support for USB Type C cable detection extcon
> + support using a TUSB320.
> +
> endif
> diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
> index 52096fd8a216..fe10a1b7d18b 100644
> --- a/drivers/extcon/Makefile
> +++ b/drivers/extcon/Makefile
> @@ -25,3 +25,4 @@ obj-$(CONFIG_EXTCON_RT8973A) += extcon-rt8973a.o
> obj-$(CONFIG_EXTCON_SM5502) += extcon-sm5502.o
> obj-$(CONFIG_EXTCON_USB_GPIO) += extcon-usb-gpio.o
> obj-$(CONFIG_EXTCON_USBC_CROS_EC) += extcon-usbc-cros-ec.o
> +obj-$(CONFIG_EXTCON_USBC_TUSB320) += extcon-usbc-tusb320.o
> diff --git a/drivers/extcon/extcon-usbc-tusb320.c b/drivers/extcon/extcon-usbc-tusb320.c
> new file mode 100644
> index 000000000000..93f1843ca89b
> --- /dev/null
> +++ b/drivers/extcon/extcon-usbc-tusb320.c
> @@ -0,0 +1,191 @@
> +// 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/irq.h>

irq.h doesn't be needed. Better to remove irq.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

Above definition contain the 'space' for indentation.
Please edit it as following:


-#define TUSB320_ATTACHED_STATE_DFP 0x1
-#define TUSB320_ATTACHED_STATE_UFP 0x2
-#define TUSB320_ATTACHED_STATE_ACC 0x3
+#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, &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);
> +
> + 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 -ENOMEM;

Use 'return PTR_ERR(priv->edev)' instead of '-ENOMEM'.

> + }
> +
> + 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,
> + dev_name(priv->dev), 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 const struct i2c_device_id tusb320_i2c_id[] = {
> + { "tusb320", 0 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, tusb320_i2c_id);

tusb320_i2c_id is not used on this driver.

> +
> +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");
>

--
Best Regards,
Chanwoo Choi
Samsung Electronics

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