Re: [PATCH v6 05/10] PCI: imx6: Simplify switch-case logic by involve core_reset callback

Manivannan Sadhasivam
2024-06-30T16:10:35Z

On Mon, Jun 17, 2024 at 04:16:41PM -0400, Frank Li wrote:
> Instead of using the switch case statement to assert/dassert the core reset
> handled by this driver itself, let's introduce a new callback core_reset()
> and define it for platforms that require it. This simplifies the code.
>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

- Mani

> ---
> drivers/pci/controller/dwc/pci-imx6.c | 134 ++++++++++++++++++----------------
> 1 file changed, 71 insertions(+), 63 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index ff9d0098294fa..6f68bee111029 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -104,6 +104,7 @@ struct imx_pcie_drvdata {
> const struct pci_epc_features *epc_features;
> int (*init_phy)(struct imx_pcie *pcie);
> int (*set_ref_clk)(struct imx_pcie *pcie, bool enable);
> + int (*core_reset)(struct imx_pcie *pcie, bool assert);
> };
>
> struct imx_pcie {
> @@ -672,35 +673,75 @@ static void imx_pcie_clk_disable(struct imx_pcie *imx_pcie)
> clk_bulk_disable_unprepare(imx_pcie->drvdata->clks_cnt, imx_pcie->clks);
> }
>
> +static int imx6sx_pcie_core_reset(struct imx_pcie *imx_pcie, bool assert)
> +{
> + if (assert)
> + regmap_set_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,
> + IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
> +
> + /* Force PCIe PHY reset */
> + regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR5, IMX6SX_GPR5_PCIE_BTNRST_RESET,
> + assert ? IMX6SX_GPR5_PCIE_BTNRST_RESET : 0);
> + return 0;
> +}
> +
> +static int imx6qp_pcie_core_reset(struct imx_pcie *imx_pcie, bool assert)
> +{
> + regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_SW_RST,
> + assert ? IMX6Q_GPR1_PCIE_SW_RST : 0);
> + if (!assert)
> + usleep_range(200, 500);
> +
> + return 0;
> +}
> +
> +static int imx6q_pcie_core_reset(struct imx_pcie *imx_pcie, bool assert)
> +{
> + if (!assert)
> + return 0;
> +
> + regmap_set_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_TEST_PD);
> + regmap_set_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR1, IMX6Q_GPR1_PCIE_REF_CLK_EN);
> +
> + return 0;
> +}
> +
> +static int imx7d_pcie_core_reset(struct imx_pcie *imx_pcie, bool assert)
> +{
> + struct dw_pcie *pci = imx_pcie->pci;
> + struct device *dev = pci->dev;
> +
> + if (assert)
> + return 0;
> +
> + /*
> + * Workaround for ERR010728, failure of PCI-e PLL VCO to
> + * oscillate, especially when cold. This turns off "Duty-cycle
> + * Corrector" and other mysterious undocumented things.
> + */
> +
> + if (likely(imx_pcie->phy_base)) {
> + /* De-assert DCC_FB_EN */
> + writel(PCIE_PHY_CMN_REG4_DCC_FB_EN, imx_pcie->phy_base + PCIE_PHY_CMN_REG4);
> + /* Assert RX_EQS and RX_EQS_SEL */
> + writel(PCIE_PHY_CMN_REG24_RX_EQ_SEL | PCIE_PHY_CMN_REG24_RX_EQ,
> + imx_pcie->phy_base + PCIE_PHY_CMN_REG24);
> + /* Assert ATT_MODE */
> + writel(PCIE_PHY_CMN_REG26_ATT_MODE, imx_pcie->phy_base + PCIE_PHY_CMN_REG26);
> + } else {
> + dev_warn(dev, "Unable to apply ERR010728 workaround. DT missing fsl,imx7d-pcie-phy phandle ?\n");
> + }
> + imx7d_pcie_wait_for_phy_pll_lock(imx_pcie);
> + return 0;
> +}
> +
> static void imx_pcie_assert_core_reset(struct imx_pcie *imx_pcie)
> {
> reset_control_assert(imx_pcie->pciephy_reset);
> reset_control_assert(imx_pcie->apps_reset);
>
> - switch (imx_pcie->drvdata->variant) {
> - case IMX6SX:
> - regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,
> - IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
> - IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
> - /* Force PCIe PHY reset */
> - regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR5,
> - IMX6SX_GPR5_PCIE_BTNRST_RESET,
> - IMX6SX_GPR5_PCIE_BTNRST_RESET);
> - break;
> - case IMX6QP:
> - regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR1,
> - IMX6Q_GPR1_PCIE_SW_RST,
> - IMX6Q_GPR1_PCIE_SW_RST);
> - break;
> - case IMX6Q:
> - regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR1,
> - IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
> - regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR1,
> - IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
> - break;
> - default:
> - break;
> - }
> + if (imx_pcie->drvdata->core_reset)
> + imx_pcie->drvdata->core_reset(imx_pcie, true);
>
> /* Some boards don't have PCIe reset GPIO. */
> if (gpio_is_valid(imx_pcie->reset_gpio))
> @@ -710,47 +751,10 @@ static void imx_pcie_assert_core_reset(struct imx_pcie *imx_pcie)
>
> static int imx_pcie_deassert_core_reset(struct imx_pcie *imx_pcie)
> {
> - struct dw_pcie *pci = imx_pcie->pci;
> - struct device *dev = pci->dev;
> -
> reset_control_deassert(imx_pcie->pciephy_reset);
>
> - switch (imx_pcie->drvdata->variant) {
> - case IMX7D:
> - /* Workaround for ERR010728, failure of PCI-e PLL VCO to
> - * oscillate, especially when cold. This turns off "Duty-cycle
> - * Corrector" and other mysterious undocumented things.
> - */
> - if (likely(imx_pcie->phy_base)) {
> - /* De-assert DCC_FB_EN */
> - writel(PCIE_PHY_CMN_REG4_DCC_FB_EN,
> - imx_pcie->phy_base + PCIE_PHY_CMN_REG4);
> - /* Assert RX_EQS and RX_EQS_SEL */
> - writel(PCIE_PHY_CMN_REG24_RX_EQ_SEL
> - | PCIE_PHY_CMN_REG24_RX_EQ,
> - imx_pcie->phy_base + PCIE_PHY_CMN_REG24);
> - /* Assert ATT_MODE */
> - writel(PCIE_PHY_CMN_REG26_ATT_MODE,
> - imx_pcie->phy_base + PCIE_PHY_CMN_REG26);
> - } else {
> - dev_warn(dev, "Unable to apply ERR010728 workaround. DT missing fsl,imx7d-pcie-phy phandle ?\n");
> - }
> -
> - imx7d_pcie_wait_for_phy_pll_lock(imx_pcie);
> - break;
> - case IMX6SX:
> - regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR5,
> - IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
> - break;
> - case IMX6QP:
> - regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR1,
> - IMX6Q_GPR1_PCIE_SW_RST, 0);
> -
> - usleep_range(200, 500);
> - break;
> - default:
> - break;
> - }
> + if (imx_pcie->drvdata->core_reset)
> + imx_pcie->drvdata->core_reset(imx_pcie, false);
>
> /* Some boards don't have PCIe reset GPIO. */
> if (gpio_is_valid(imx_pcie->reset_gpio)) {
> @@ -1458,6 +1462,7 @@ static const struct imx_pcie_drvdata drvdata[] = {
> .mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
> .init_phy = imx_pcie_init_phy,
> .set_ref_clk = imx6q_pcie_set_ref_clk,
> + .core_reset = imx6q_pcie_core_reset,
> },
> [IMX6SX] = {
> .variant = IMX6SX,
> @@ -1473,6 +1478,7 @@ static const struct imx_pcie_drvdata drvdata[] = {
> .mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
> .init_phy = imx6sx_pcie_init_phy,
> .set_ref_clk = imx6sx_pcie_set_ref_clk,
> + .core_reset = imx6sx_pcie_core_reset,
> },
> [IMX6QP] = {
> .variant = IMX6QP,
> @@ -1489,6 +1495,7 @@ static const struct imx_pcie_drvdata drvdata[] = {
> .mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
> .init_phy = imx_pcie_init_phy,
> .set_ref_clk = imx6q_pcie_set_ref_clk,
> + .core_reset = imx6qp_pcie_core_reset,
> },
> [IMX7D] = {
> .variant = IMX7D,
> @@ -1502,6 +1509,7 @@ static const struct imx_pcie_drvdata drvdata[] = {
> .mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
> .init_phy = imx7d_pcie_init_phy,
> .set_ref_clk = imx7d_pcie_set_ref_clk,
> + .core_reset = imx7d_pcie_core_reset,
> },
> [IMX8MQ] = {
> .variant = IMX8MQ,
>
> --
> 2.34.1
>

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