On 25.12.2023 09:44, Luo Jie wrote:
> The ethernet LDO provides the clock for the ethernet PHY that
> is connected with PCS, each LDO enables the clock output to
> each PCS, after the clock output enablement, the PHY GPIO reset
> can take effect.
>
> For the PHY taking the MDIO bus level GPIO reset, the ethernet
> LDO should be enabled before the MDIO bus register.
>
> For example, the qca8084 PHY takes the MDIO bus level GPIO
> reset for quad PHYs, there is another reason for qca8084 PHY
> using MDIO bus level GPIO reset instead of PHY level GPIO
> reset as below.
>
> The work sequence of qca8084:
> 1. enable ethernet LDO.
> 2. GPIO reset on quad PHYs.
> 3. register clock provider based on MDIO device of qca8084.
> 4. PHY probe function called for initializing common clocks.
> 5. PHY capabilities acquirement.
>
> If qca8084 takes PHY level GPIO reset in the step 4, the clock
> provider of qca8084 can't be registered correctly, since the
> clock parent(reading the current qca8084 hardware registers in
> step 3) of the registered clocks is deserted after GPIO reset.
>
> There are two PCS(UNIPHY) supported in SOC side on ipq5332,
> and three PCS(UNIPHY) supported on ipq9574.
>
> Signed-off-by: Luo Jie <quic_luoj@xxxxxxxxxxx>
> ---
> drivers/net/mdio/mdio-ipq4019.c | 51 +++++++++++++++++++++------------
> 1 file changed, 32 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/net/mdio/mdio-ipq4019.c b/drivers/net/mdio/mdio-ipq4019.c
> index abd8b508ec16..5273864fabb3 100644
> --- a/drivers/net/mdio/mdio-ipq4019.c
> +++ b/drivers/net/mdio/mdio-ipq4019.c
> @@ -37,9 +37,12 @@
>
> #define IPQ_PHY_SET_DELAY_US 100000
>
> +/* Maximum SOC PCS(uniphy) number on IPQ platform */
> +#define ETH_LDO_RDY_CNT 3
> +
> struct ipq4019_mdio_data {
> - void __iomem *membase;
> - void __iomem *eth_ldo_rdy;
> + void __iomem *membase;
> + void __iomem *eth_ldo_rdy[ETH_LDO_RDY_CNT];
> struct clk *mdio_clk;
> };
>
> @@ -206,19 +209,8 @@ static int ipq4019_mdio_write_c22(struct mii_bus *bus, int mii_id, int regnum,
> static int ipq_mdio_reset(struct mii_bus *bus)
> {
> struct ipq4019_mdio_data *priv = bus->priv;
> - u32 val;
> int ret;
>
> - /* To indicate CMN_PLL that ethernet_ldo has been ready if platform resource 1
> - * is specified in the device tree.
> - */
> - if (priv->eth_ldo_rdy) {
> - val = readl(priv->eth_ldo_rdy);
> - val |= BIT(0);
> - writel(val, priv->eth_ldo_rdy);
> - fsleep(IPQ_PHY_SET_DELAY_US);
> - }
> -
> /* Configure MDIO clock source frequency if clock is specified in the device tree */
> ret = clk_set_rate(priv->mdio_clk, IPQ_MDIO_CLK_RATE);
> if (ret)
> @@ -236,7 +228,7 @@ static int ipq4019_mdio_probe(struct platform_device *pdev)
> struct ipq4019_mdio_data *priv;
> struct mii_bus *bus;
> struct resource *res;
> - int ret;
> + int ret, index;
>
> bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*priv));
> if (!bus)
> @@ -252,11 +244,32 @@ static int ipq4019_mdio_probe(struct platform_device *pdev)
> if (IS_ERR(priv->mdio_clk))
> return PTR_ERR(priv->mdio_clk);
>
> - /* The platform resource is provided on the chipset IPQ5018 */
> - /* This resource is optional */
> - res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> - if (res)
> - priv->eth_ldo_rdy = devm_ioremap_resource(&pdev->dev, res);
> + /* These platform resources are provided on the chipset IPQ5018 or
> + * IPQ5332.
> + */
> + /* This resource are optional */
> + for (index = 0; index < ETH_LDO_RDY_CNT; index++) {
> + res = platform_get_resource(pdev, IORESOURCE_MEM, index + 1);
> + if (res) {
if (!res)
break
> + priv->eth_ldo_rdy[index] = devm_ioremap(&pdev->dev,
> + res->start,
> + resource_size(res));
> +
> + /* The ethernet LDO enable is necessary to reset PHY
> + * by GPIO, some PHY(such as qca8084) GPIO reset uses
> + * the MDIO level reset, so this function should be
> + * called before the MDIO bus register.
> + */
> + if (priv->eth_ldo_rdy[index]) {
> + u32 val;
> +
> + val = readl(priv->eth_ldo_rdy[index]);
> + val |= BIT(0);
> + writel(val, priv->eth_ldo_rdy[index]);
> + fsleep(IPQ_PHY_SET_DELAY_US);
fsleep should only be used when the argument is variable
Konrad
