Re: [PATCH 4/4] RFC: net: dsa: realtek-smi: Add Realtek SMI driver

[Andrew Lunn <andrew@lunn.ch>]

Hi Linus

> +static int realtek_smi_read_reg(struct realtek_smi *smi, u32 addr, u32 *data)
> +{
> +	unsigned long flags;
> +	u8 lo = 0;
> +	u8 hi = 0;
> +	int ret;
> +
> +	spin_lock_irqsave(&smi->lock, flags);
> +
> +	realtek_smi_start(smi);
> +
> +	/* send READ command */
> +	ret = realtek_smi_write_byte(smi, smi->cmd_read);
> +	if (ret)
> +		goto out;
> +
> +	/* set ADDR[7:0] */
> +	ret = realtek_smi_write_byte(smi, addr & 0xff);
> +	if (ret)
> +		goto out;
> +
> +	/* set ADDR[15:8] */
> +	ret = realtek_smi_write_byte(smi, addr >> 8);
> +	if (ret)
> +		goto out;
> +
> +	/* read DATA[7:0] */
> +	realtek_smi_read_byte0(smi, &lo);
> +	/* read DATA[15:8] */
> +	realtek_smi_read_byte1(smi, &hi);
> +
> +	*data = ((u32) lo) | (((u32) hi) << 8);

If i'm reading this correct, addr is a u16 and data is also u16?  So
it is pretty similar to SMI.

I'm wondering if this should be modelled as a normal MDIO bus? Put the
driver as drivers/net/mdio-realtek.c?

I need to study the rest of the code to see if this is a good idea or
not.

	Andrew