On 3/4/25 10:56 PM, Melody Olvera wrote:
> From: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
>
> SM8750 utilizes an eUSB2 PHY from M31. Add the initialization
> sequences to bring it out of reset and into an operational state. This
> differs to the M31 USB driver, in that the M31 eUSB2 driver will
> require a connection to an eUSB2 repeater. This PHY driver will handle
> the initialization of the associated eUSB2 repeater when required.
>
> Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> Signed-off-by: Melody Olvera <quic_molvera@xxxxxxxxxxx>
> ---
[...]
> +static int msm_m31_eusb2_write_readback(void __iomem *base, u32 offset,
> + const u32 mask, u32 val)
> +{
> + u32 write_val;
> + u32 tmp;
> +
> + tmp = readl_relaxed(base + offset);
> + tmp &= ~mask;
> + write_val = tmp | val;
> +
> + writel_relaxed(write_val, base + offset);
> +
> + tmp = readl_relaxed(base + offset);
> + tmp &= mask;
> +
> + if (tmp != val) {
> + pr_err("write: %x to offset: %x FAILED\n", val, offset);
> + return -EINVAL;
> + }
> +
> + return 0;
Is there a reason we need to read back every write?
Does this have to do with some funny write buffering?
Konrad
