On Wed, Feb 26, 2025 at 06:36:00PM +0800, Wenbin Yao wrote:
> From: Qiang Yu <quic_qianyu@xxxxxxxxxxx>
>
> Some QCOM PCIe PHYs support no_csr reset. Unlike BCR reset which resets the
> whole PHY (hardware and register), no_csr reset only resets PHY hardware
> but retains register values, which means PHY setting can be skipped during
> PHY init if PCIe link is enabled in booltloader and only no_csr is toggled
> after that.
>
> Hence, determine whether the PHY has been enabled in bootloader by
> verifying QPHY_START_CTRL register. If it's programmed and no_csr reset is
> available, skip BCR reset and PHY register setting to establish the PCIe
> link with bootloader - programmed PHY settings.
>
> Signed-off-by: Qiang Yu <quic_qianyu@xxxxxxxxxxx>
> Signed-off-by: Wenbin Yao <quic_wenbyao@xxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
One nit below.
> ---
> drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 69 ++++++++++++++++++++----
> 1 file changed, 59 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> index 219266125cf2..c3642d1807e4 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> @@ -2805,6 +2805,7 @@ struct qmp_pcie {
>
> const struct qmp_phy_cfg *cfg;
> bool tcsr_4ln_config;
> + bool skip_init;
>
> void __iomem *serdes;
> void __iomem *pcs;
> @@ -3976,18 +3977,38 @@ static int qmp_pcie_init(struct phy *phy)
> {
> struct qmp_pcie *qmp = phy_get_drvdata(phy);
> const struct qmp_phy_cfg *cfg = qmp->cfg;
> + void __iomem *pcs = qmp->pcs;
> + bool phy_initialized = !!(readl(pcs + cfg->regs[QPHY_START_CTRL]));
> int ret;
>
> + qmp->skip_init = qmp->nocsr_reset && phy_initialized;
> + /*
> + * We need to check the existence of init sequences in two cases:
> + * 1. The PHY doesn't support no_csr reset.
> + * 2. The PHY supports no_csr reset but isn't initialized by bootloader.
> + * As we can't skip init in these two cases.
> + */
> + if (!qmp->skip_init && !cfg->tbls.serdes_num) {
> + dev_err(qmp->dev, "no init sequences are available\n");
"Init sequence not available\n"
> + return -EINVAL;
-ENODATA
- Mani
--
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