Re: [RESEND PATCH] net: ethernet: ti: davinci_mdio: Add workaround for errata i2329
From: Andrew Lunn
Date: Mon Aug 08 2022 - 16:13:49 EST
> +static int davinci_mdio_sw_read(struct mii_bus *bus, int phy_id, int phy_reg)
> +{
> + struct davinci_mdio_data *data = bus->priv;
> + u32 reg, i;
> + int ret;
> + u8 ack;
> +
> + if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
> + return -EINVAL;
> +
> + ret = pm_runtime_get_sync(data->dev);
> + if (ret < 0) {
> + pm_runtime_put_noidle(data->dev);
> + return ret;
> + }
> +
> + davinci_mdio_disable(data);
> + davinci_mdio_enable_manual_mode(data);
> + davinci_mdio_sw_preamble(data);
> +
> + davinci_mdio_sw_clr_bit(data, MDIO_MDCLK);
> + davinci_mdio_sw_set_bit(data, MDIO_OE);
> +
> + /* Issue clause 22 MII read function {0,1,1,0} */
> + davinci_mdio_man_send_pattern(data, C22_BITRANGE, C22_READ_PATTERN);
> +
> + /* Send the device number MSB first */
> + davinci_mdio_man_send_pattern(data, PHY_BITRANGE, phy_id);
> +
> + /* Send the register number MSB first */
> + davinci_mdio_man_send_pattern(data, PHY_BITRANGE, phy_reg);
> +
> + /* Send turn around cycles */
> + davinci_mdio_sw_clr_bit(data, MDIO_OE);
> +
> + davinci_mdio_toggle_man_bit(data, MDIO_MDCLK);
> +
> + ack = davinci_mdio_test_man_bit(data, MDIO_PIN);
> + davinci_mdio_toggle_man_bit(data, MDIO_MDCLK);
> +
> + reg = 0;
> + if (ack == 0) {
> + for (i = MDIO_BITRANGE; i; i = i >> 1) {
> + if (davinci_mdio_test_man_bit(data, MDIO_PIN))
> + reg |= i;
> +
> + davinci_mdio_toggle_man_bit(data, MDIO_MDCLK);
> + }
> + } else {
> + for (i = MDIO_BITRANGE; i; i = i >> 1)
> + davinci_mdio_toggle_man_bit(data, MDIO_MDCLK);
> +
> + reg = 0xFFFF;
> + }
> +
> + davinci_mdio_sw_clr_bit(data, MDIO_MDCLK);
> + davinci_mdio_sw_set_bit(data, MDIO_MDCLK);
> + davinci_mdio_sw_set_bit(data, MDIO_MDCLK);
> + davinci_mdio_toggle_man_bit(data, MDIO_MDCLK);
You appear to of re-invented drivers/net/mdio/mdio-bitbang.c
If there is a reason this cannot be used, please at least state it in
the commit message.
Andrew