[PATCH v2 1/1] phy: qualcomm: m31-eusb2: Add register XCFGI_159_152 for SE0 recovery

[Abel Vesa]

On 26-10-26 18:55:45, Peter Chen wrote:
> From: Elson Serrao <elson.serrao at oss.qualcomm.com>
> 
> This patch introduces support for the XCFGI_159_152 register to enable a
> hardware-based SE0 recovery mechanism in the M31 PHY when operating in
> host mode.
> 
> During PHY initialization, spurious pulses from external devices can
> interfere with speed negotiation, potentially leading to abnormal
> behavior. To mitigate this, the M31 PHY provides a fail-safe mechanism
> controlled by bit 159 of the XCFGI register.
> 
> When XCFG_SE0_TIMEOUT_EN (bit 159) is set, a hardware counter is
> activated to monitor the SE0 state. If SE0 persists for more than 2.5 ms
> before entering L0 mode, the PHY interprets this as bus inactivity and
> resets the state machine to its default state. After transitioning to
> L0, the PHY resumes normal operation in accordance with the eUSB
> specification.
> 
> Fixes: 9c8504861cc4 ("phy: qcom: Add M31 based eUSB2 PHY driver")
> Reviewed-by: Konrad Dybcio <konrad.dybcio at oss.qualcomm.com>
> Signed-off-by: Elson Serrao <elson.serrao at oss.qualcomm.com>
> Signed-off-by: Peter Chen <peter.chen at oss.qualcomm.com>

Reviewed-by: Abel Vesa <abel.vesa at oss.qualcomm.com>