On Sat, Nov 01, 2025 at 09:29:36AM +0530, Krishna Chaitanya Chundru wrote:
> Add support for assert_perst() for switches like TC9563, which require
> configuration before the PCIe link is established. Such devices use
> this function op to assert the PERST# before configuring the device
> and once the configuration is done they de-assert the PERST#.
>
> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>
- Mani
> ---
> drivers/pci/controller/dwc/pcie-qcom.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 805edbbfe7eba496bc99ca82051dee43d240f359..cdc605b44e19e17319c39933f22d0b7710c5e9ef 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -696,6 +696,18 @@ static int qcom_pcie_post_init_1_0_0(struct qcom_pcie *pcie)
> return 0;
> }
>
> +static int qcom_pcie_assert_perst(struct dw_pcie *pci, bool assert)
> +{
> + struct qcom_pcie *pcie = to_qcom_pcie(pci);
> +
> + if (assert)
> + qcom_ep_reset_assert(pcie);
> + else
> + qcom_ep_reset_deassert(pcie);
> +
> + return 0;
> +}
> +
> static void qcom_pcie_2_3_2_ltssm_enable(struct qcom_pcie *pcie)
> {
> u32 val;
> @@ -1516,6 +1528,7 @@ static const struct qcom_pcie_cfg cfg_fw_managed = {
> static const struct dw_pcie_ops dw_pcie_ops = {
> .link_up = qcom_pcie_link_up,
> .start_link = qcom_pcie_start_link,
> + .assert_perst = qcom_pcie_assert_perst,
> };
>
> static int qcom_pcie_icc_init(struct qcom_pcie *pcie)
>
> --
> 2.34.1
>
--
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