[PATCH v2 4/7] usb: onboard-hub: Add i2c initialization for usb5744 hub

[Marek Vasut]

On 9/27/24 9:01 AM, Venkatesh Yadav Abbarapu wrote:

[...]

>   struct onboard_hub {
>   	struct udevice *vdd;
>   	struct gpio_desc *reset_gpio;
> @@ -21,8 +27,86 @@ struct onboard_hub {
>   struct onboard_hub_data {
>   	unsigned long reset_us;
>   	unsigned long power_on_delay_us;
> +	int (*i2c_init)(struct udevice *dev);

Why not call it simply "init" ?

>   };
>   
> +static int usb5744_i2c_init(struct udevice *dev)
> +{
> +	/*
> +	 *  Prevent the MCU from the putting the HUB in suspend mode through register write.
> +	 *  The BYPASS_UDC_SUSPEND bit (Bit 3) of the RuntimeFlags2 register at address
> +	 *  0x411D controls this aspect of the hub.
> +	 *  Format to write to hub registers via SMBus- 2D 00 00 05 00 01 41 1D 08
> +	 *  Byte 0: Address of slave 2D
> +	 *  Byte 1: Memory address 00
> +	 *  Byte 2: Memory address 00
> +	 *  Byte 3: Number of bytes to write to memory
> +	 *  Byte 4: Write configuration register (00)
> +	 *  Byte 5: Write the number of data bytes (01- 1 data byte)
> +	 *  Byte 6: LSB of register address 0x41
> +	 *  Byte 7: MSB of register address 0x1D
> +	 *  Byte 8: value to be written to the register
> +	 */
> +	u8 data_buf[8] = {0x0, 0x5, 0x0, 0x1, 0x41, 0x1D, 0x08};
> +	int ret, slave_addr;
> +	u8 buf = USB5744_COMMAND_ATTACH;
> +	u8 config_reg_access_buf = USB5744_CONFIG_REG_ACCESS;
> +	struct dm_i2c_chip *i2c_chip;
> +	struct ofnode_phandle_args phandle;
> +	struct udevice *i2c_bus = NULL, *i2c_dev;

Make sure this list of variables is ordered as reverse xmas tree if 
possible.

> +	if (dev_read_phandle_with_args(dev, "i2c-bus", NULL, 0, 0, &phandle)) {

Return the error code:

ret = dev_read_phandle_with_args()
if (ret) {
...
return ret;
}

> +		dev_err(dev, "i2c-bus not specified\n");
> +		return -ENOENT;
> +	}
> +
> +	ret = device_get_global_by_ofnode(ofnode_get_parent(phandle.node), &i2c_bus);
> +	if (ret) {
> +		dev_err(dev, "Failed to get i2c node, err: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = ofnode_read_u32(phandle.node, "reg", &slave_addr);
> +	if (ret)
> +		return ret;
> +
> +	ret = i2c_get_chip(i2c_bus, slave_addr, 1, &i2c_dev);
> +	if (ret) {
> +		dev_dbg(dev, "%s: can't find i2c chip device for addr %x\n", __func__,
> +			slave_addr);
> +		return ret;
> +	}
> +
> +	i2c_chip = dev_get_parent_plat(i2c_dev);

Can this fail ? If so, is return 0 really the correct thing to do ?

> +	if (!i2c_chip)
> +		return 0;
> +
> +	i2c_chip->flags &= ~DM_I2C_CHIP_WR_ADDRESS;
> +	/* SMBus write command */
> +	ret = dm_i2c_write(i2c_dev, 0, (uint8_t *)&data_buf, 8);

Is the uint8_t * cast necessary ?

> +	if (ret) {
> +		dev_err(dev, "data_buf i2c_write failed, err:%d\n", ret);
> +		return ret;
> +	}
> +
> +	/* Configuration register access command */
> +	ret = dm_i2c_write(i2c_dev, USB5744_CONFIG_REG_ACCESS_LSB,
> +			   (uint8_t *)&config_reg_access_buf, 2);

Is the uint8_t * cast necessary ?

> +	if (ret) {
> +		dev_err(dev, "config_reg_access i2c_write failed, err: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* USB Attach with SMBus */
> +	ret = dm_i2c_write(i2c_dev, USB5744_COMMAND_ATTACH_LSB, (uint8_t *)&buf, 2);

Is the uint8_t * cast necessary ?

> +	if (ret) {
> +		dev_err(dev, "usb_attach i2c_write failed, err: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>   static int usb_onboard_hub_probe(struct udevice *dev)
>   {
>   	struct onboard_hub_data *data =
> @@ -61,7 +145,21 @@ static int usb_onboard_hub_probe(struct udevice *dev)
>   		udelay(data->power_on_delay_us);
>   	}
[...]