Re: [PATCH v4 2/2] PCI: qcom: Move all DBI register accesses after phy_power_on()

Bjorn Helgaas
2022-07-07T19:41:49Z

On Fri, Jun 24, 2022 at 12:44:20PM +0200, Robert Marko wrote:
> IPQ8074 requires the PHY to be powered on before accessing DBI registers.
> It's not clear whether other variants have the same dependency, but there
> seems to be no reason for them to be different, so move all the DBI
> accesses from .init() to .post_init() so they are all after phy_power_on().
>
> Signed-off-by: Robert Marko <robimarko@gmail.com>

Would any of the qcom driver folks care to review and ack this?
Stanimir, Andy, Bjorn A (from get_maintainer.pl)?

> ---
> Changes in v4:
> * Move 2.7.0 accesses as well
> * Correct title and description (Bjorn)
> ---
> drivers/pci/controller/dwc/pcie-qcom.c | 215 ++++++++++++++-----------
> 1 file changed, 119 insertions(+), 96 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 24708d5d817d..f1a156052fe7 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -348,8 +348,6 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie)
> struct qcom_pcie_resources_2_1_0 *res = &pcie->res.v2_1_0;
> struct dw_pcie *pci = pcie->pci;
> struct device *dev = pci->dev;
> - struct device_node *node = dev->of_node;
> - u32 val;
> int ret;
>
> /* reset the PCIe interface as uboot can leave it undefined state */
> @@ -360,8 +358,6 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie)
> reset_control_assert(res->ext_reset);
> reset_control_assert(res->phy_reset);
>
> - writel(1, pcie->parf + PCIE20_PARF_PHY_CTRL);
> -
> ret = regulator_bulk_enable(ARRAY_SIZE(res->supplies), res->supplies);
> if (ret < 0) {
> dev_err(dev, "cannot enable regulators\n");
> @@ -408,6 +404,35 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie)
> if (ret)
> goto err_clks;
>
> + return 0;
> +
> +err_clks:
> + reset_control_assert(res->axi_reset);
> +err_deassert_axi:
> + reset_control_assert(res->por_reset);
> +err_deassert_por:
> + reset_control_assert(res->pci_reset);
> +err_deassert_pci:
> + reset_control_assert(res->phy_reset);
> +err_deassert_phy:
> + reset_control_assert(res->ext_reset);
> +err_deassert_ext:
> + reset_control_assert(res->ahb_reset);
> +err_deassert_ahb:
> + regulator_bulk_disable(ARRAY_SIZE(res->supplies), res->supplies);
> +
> + return ret;
> +}
> +
> +static int qcom_pcie_post_init_2_1_0(struct qcom_pcie *pcie)
> +{
> + struct dw_pcie *pci = pcie->pci;
> + struct device *dev = pci->dev;
> + struct device_node *node = dev->of_node;
> + u32 val;
> +
> + writel(1, pcie->parf + PCIE20_PARF_PHY_CTRL);
> +
> /* enable PCIe clocks and resets */
> val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
> val &= ~BIT(0);
> @@ -451,23 +476,6 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie)
> pci->dbi_base + PCIE20_AXI_MSTR_RESP_COMP_CTRL1);
>
> return 0;
> -
> -err_clks:
> - reset_control_assert(res->axi_reset);
> -err_deassert_axi:
> - reset_control_assert(res->por_reset);
> -err_deassert_por:
> - reset_control_assert(res->pci_reset);
> -err_deassert_pci:
> - reset_control_assert(res->phy_reset);
> -err_deassert_phy:
> - reset_control_assert(res->ext_reset);
> -err_deassert_ext:
> - reset_control_assert(res->ahb_reset);
> -err_deassert_ahb:
> - regulator_bulk_disable(ARRAY_SIZE(res->supplies), res->supplies);
> -
> - return ret;
> }
>
> static int qcom_pcie_get_resources_1_0_0(struct qcom_pcie *pcie)
> @@ -555,16 +563,6 @@ static int qcom_pcie_init_1_0_0(struct qcom_pcie *pcie)
> goto err_slave;
> }
>
> - /* change DBI base address */
> - writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
> -
> - if (IS_ENABLED(CONFIG_PCI_MSI)) {
> - u32 val = readl(pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
> -
> - val |= BIT(31);
> - writel(val, pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
> - }
> -
> return 0;
> err_slave:
> clk_disable_unprepare(res->slave_bus);
> @@ -580,6 +578,22 @@ static int qcom_pcie_init_1_0_0(struct qcom_pcie *pcie)
> return ret;
> }
>
> +static int qcom_pcie_post_init_1_0_0(struct qcom_pcie *pcie)
> +{
> +
> + /* change DBI base address */
> + writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
> +
> + if (IS_ENABLED(CONFIG_PCI_MSI)) {
> + u32 val = readl(pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
> +
> + val |= BIT(31);
> + writel(val, pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
> + }
> +
> + return 0;
> +}
> +
> static void qcom_pcie_2_3_2_ltssm_enable(struct qcom_pcie *pcie)
> {
> u32 val;
> @@ -648,7 +662,6 @@ static int qcom_pcie_init_2_3_2(struct qcom_pcie *pcie)
> struct qcom_pcie_resources_2_3_2 *res = &pcie->res.v2_3_2;
> struct dw_pcie *pci = pcie->pci;
> struct device *dev = pci->dev;
> - u32 val;
> int ret;
>
> ret = regulator_bulk_enable(ARRAY_SIZE(res->supplies), res->supplies);
> @@ -681,27 +694,6 @@ static int qcom_pcie_init_2_3_2(struct qcom_pcie *pcie)
> goto err_slave_clk;
> }
>
> - /* enable PCIe clocks and resets */
> - val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
> - val &= ~BIT(0);
> - writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
> -
> - /* change DBI base address */
> - writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
> -
> - /* MAC PHY_POWERDOWN MUX DISABLE */
> - val = readl(pcie->parf + PCIE20_PARF_SYS_CTRL);
> - val &= ~BIT(29);
> - writel(val, pcie->parf + PCIE20_PARF_SYS_CTRL);
> -
> - val = readl(pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
> - val |= BIT(4);
> - writel(val, pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
> -
> - val = readl(pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2);
> - val |= BIT(31);
> - writel(val, pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2);
> -
> return 0;
>
> err_slave_clk:
> @@ -722,8 +714,30 @@ static int qcom_pcie_post_init_2_3_2(struct qcom_pcie *pcie)
> struct qcom_pcie_resources_2_3_2 *res = &pcie->res.v2_3_2;
> struct dw_pcie *pci = pcie->pci;
> struct device *dev = pci->dev;
> + u32 val;
> int ret;
>
> + /* enable PCIe clocks and resets */
> + val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
> + val &= ~BIT(0);
> + writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
> +
> + /* change DBI base address */
> + writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
> +
> + /* MAC PHY_POWERDOWN MUX DISABLE */
> + val = readl(pcie->parf + PCIE20_PARF_SYS_CTRL);
> + val &= ~BIT(29);
> + writel(val, pcie->parf + PCIE20_PARF_SYS_CTRL);
> +
> + val = readl(pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
> + val |= BIT(4);
> + writel(val, pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
> +
> + val = readl(pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2);
> + val |= BIT(31);
> + writel(val, pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2);
> +
> ret = clk_prepare_enable(res->pipe_clk);
> if (ret) {
> dev_err(dev, "cannot prepare/enable pipe clock\n");
> @@ -837,7 +851,6 @@ static int qcom_pcie_init_2_4_0(struct qcom_pcie *pcie)
> struct qcom_pcie_resources_2_4_0 *res = &pcie->res.v2_4_0;
> struct dw_pcie *pci = pcie->pci;
> struct device *dev = pci->dev;
> - u32 val;
> int ret;
>
> ret = reset_control_assert(res->axi_m_reset);
> @@ -962,6 +975,33 @@ static int qcom_pcie_init_2_4_0(struct qcom_pcie *pcie)
> if (ret)
> goto err_clks;
>
> + return 0;
> +
> +err_clks:
> + reset_control_assert(res->ahb_reset);
> +err_rst_ahb:
> + reset_control_assert(res->pwr_reset);
> +err_rst_pwr:
> + reset_control_assert(res->axi_s_reset);
> +err_rst_axi_s:
> + reset_control_assert(res->axi_m_sticky_reset);
> +err_rst_axi_m_sticky:
> + reset_control_assert(res->axi_m_reset);
> +err_rst_axi_m:
> + reset_control_assert(res->pipe_sticky_reset);
> +err_rst_pipe_sticky:
> + reset_control_assert(res->pipe_reset);
> +err_rst_pipe:
> + reset_control_assert(res->phy_reset);
> +err_rst_phy:
> + reset_control_assert(res->phy_ahb_reset);
> + return ret;
> +}
> +
> +static int qcom_pcie_post_init_2_4_0(struct qcom_pcie *pcie)
> +{
> + u32 val;
> +
> /* enable PCIe clocks and resets */
> val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
> val &= ~BIT(0);
> @@ -984,26 +1024,6 @@ static int qcom_pcie_init_2_4_0(struct qcom_pcie *pcie)
> writel(val, pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2);
>
> return 0;
> -
> -err_clks:
> - reset_control_assert(res->ahb_reset);
> -err_rst_ahb:
> - reset_control_assert(res->pwr_reset);
> -err_rst_pwr:
> - reset_control_assert(res->axi_s_reset);
> -err_rst_axi_s:
> - reset_control_assert(res->axi_m_sticky_reset);
> -err_rst_axi_m_sticky:
> - reset_control_assert(res->axi_m_reset);
> -err_rst_axi_m:
> - reset_control_assert(res->pipe_sticky_reset);
> -err_rst_pipe_sticky:
> - reset_control_assert(res->pipe_reset);
> -err_rst_pipe:
> - reset_control_assert(res->phy_reset);
> -err_rst_phy:
> - reset_control_assert(res->phy_ahb_reset);
> - return ret;
> }
>
> static int qcom_pcie_get_resources_2_3_3(struct qcom_pcie *pcie)
> @@ -1237,7 +1257,6 @@ static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie)
> struct qcom_pcie_resources_2_7_0 *res = &pcie->res.v2_7_0;
> struct dw_pcie *pci = pcie->pci;
> struct device *dev = pci->dev;
> - u32 val;
> int ret;
>
> ret = regulator_bulk_enable(ARRAY_SIZE(res->supplies), res->supplies);
> @@ -1271,6 +1290,28 @@ static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie)
> /* Wait for reset to complete, required on SM8450 */
> usleep_range(1000, 1500);
>
> + return 0;
> +err_disable_clocks:
> + clk_bulk_disable_unprepare(res->num_clks, res->clks);
> +err_disable_regulators:
> + regulator_bulk_disable(ARRAY_SIZE(res->supplies), res->supplies);
> +
> + return ret;
> +}
> +
> +static void qcom_pcie_deinit_2_7_0(struct qcom_pcie *pcie)
> +{
> + struct qcom_pcie_resources_2_7_0 *res = &pcie->res.v2_7_0;
> +
> + clk_bulk_disable_unprepare(res->num_clks, res->clks);
> + regulator_bulk_disable(ARRAY_SIZE(res->supplies), res->supplies);
> +}
> +
> +static int qcom_pcie_post_init_2_7_0(struct qcom_pcie *pcie)
> +{
> + struct qcom_pcie_resources_2_7_0 *res = &pcie->res.v2_7_0;
> + u32 val;
> +
> /* configure PCIe to RC mode */
> writel(DEVICE_TYPE_RC, pcie->parf + PCIE20_PARF_DEVICE_TYPE);
>
> @@ -1297,27 +1338,6 @@ static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie)
> writel(val, pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
> }
>
> - return 0;
> -err_disable_clocks:
> - clk_bulk_disable_unprepare(res->num_clks, res->clks);
> -err_disable_regulators:
> - regulator_bulk_disable(ARRAY_SIZE(res->supplies), res->supplies);
> -
> - return ret;
> -}
> -
> -static void qcom_pcie_deinit_2_7_0(struct qcom_pcie *pcie)
> -{
> - struct qcom_pcie_resources_2_7_0 *res = &pcie->res.v2_7_0;
> -
> - clk_bulk_disable_unprepare(res->num_clks, res->clks);
> - regulator_bulk_disable(ARRAY_SIZE(res->supplies), res->supplies);
> -}
> -
> -static int qcom_pcie_post_init_2_7_0(struct qcom_pcie *pcie)
> -{
> - struct qcom_pcie_resources_2_7_0 *res = &pcie->res.v2_7_0;
> -
> /* Set pipe clock as clock source for pcie_pipe_clk_src */
> if (pcie->cfg->pipe_clk_need_muxing)
> clk_set_parent(res->pipe_clk_src, res->phy_pipe_clk);
> @@ -1569,6 +1589,7 @@ static const struct dw_pcie_host_ops qcom_pcie_dw_ops = {
> static const struct qcom_pcie_ops ops_2_1_0 = {
> .get_resources = qcom_pcie_get_resources_2_1_0,
> .init = qcom_pcie_init_2_1_0,
> + .post_init = qcom_pcie_post_init_2_1_0,
> .deinit = qcom_pcie_deinit_2_1_0,
> .ltssm_enable = qcom_pcie_2_1_0_ltssm_enable,
> };
> @@ -1577,6 +1598,7 @@ static const struct qcom_pcie_ops ops_2_1_0 = {
> static const struct qcom_pcie_ops ops_1_0_0 = {
> .get_resources = qcom_pcie_get_resources_1_0_0,
> .init = qcom_pcie_init_1_0_0,
> + .post_init = qcom_pcie_post_init_1_0_0,
> .deinit = qcom_pcie_deinit_1_0_0,
> .ltssm_enable = qcom_pcie_2_1_0_ltssm_enable,
> };
> @@ -1595,6 +1617,7 @@ static const struct qcom_pcie_ops ops_2_3_2 = {
> static const struct qcom_pcie_ops ops_2_4_0 = {
> .get_resources = qcom_pcie_get_resources_2_4_0,
> .init = qcom_pcie_init_2_4_0,
> + .post_init = qcom_pcie_post_init_2_4_0,
> .deinit = qcom_pcie_deinit_2_4_0,
> .ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
> };
> --
> 2.36.1
>