Re: [PATCH v5 6/7] phy: freescale: imx8m-pcie: Add iMX8MP PCIe PHY support

From: Lucas Stach
Date: Tue Aug 30 2022 - 09:07:47 EST

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In reply to: Richard Zhu: "[PATCH v5 6/7] phy: freescale: imx8m-pcie: Add iMX8MP PCIe PHY support"
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Am Dienstag, dem 30.08.2022 um 15:46 +0800 schrieb Richard Zhu:
> Add i.MX8MP PCIe PHY support.
>
> Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
> Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> Tested-by: Marek Vasut <marex@xxxxxxx>
> Tested-by: Richard Leitner <richard.leitner@xxxxxxxxxxx>
> Tested-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
> ---
> drivers/phy/freescale/phy-fsl-imx8m-pcie.c | 137 +++++++++++++--------
> 1 file changed, 89 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/phy/freescale/phy-fsl-imx8m-pcie.c b/drivers/phy/freescale/phy-fsl-imx8m-pcie.c
> index ad7d2edfc414..c76e3a1a5f51 100644
> --- a/drivers/phy/freescale/phy-fsl-imx8m-pcie.c
> +++ b/drivers/phy/freescale/phy-fsl-imx8m-pcie.c
> @@ -11,6 +11,9 @@
> #include <linux/mfd/syscon.h>
> #include <linux/mfd/syscon/imx7-iomuxc-gpr.h>
> #include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/of_device.h>
> #include <linux/phy/phy.h>
> #include <linux/platform_device.h>
> #include <linux/regmap.h>
> @@ -31,12 +34,10 @@
> #define IMX8MM_PCIE_PHY_CMN_REG065 0x194
> #define ANA_AUX_RX_TERM (BIT(7) | BIT(4))
> #define ANA_AUX_TX_LVL GENMASK(3, 0)
> -#define IMX8MM_PCIE_PHY_CMN_REG75 0x1D4
> -#define PCIE_PHY_CMN_REG75_PLL_DONE 0x3
> +#define IMX8MM_PCIE_PHY_CMN_REG075 0x1D4
> +#define ANA_PLL_DONE 0x3
> #define PCIE_PHY_TRSV_REG5 0x414
> -#define PCIE_PHY_TRSV_REG5_GEN1_DEEMP 0x2D
> #define PCIE_PHY_TRSV_REG6 0x418
> -#define PCIE_PHY_TRSV_REG6_GEN2_DEEMP 0xF
>
> #define IMX8MM_GPR_PCIE_REF_CLK_SEL GENMASK(25, 24)
> #define IMX8MM_GPR_PCIE_REF_CLK_PLL FIELD_PREP(IMX8MM_GPR_PCIE_REF_CLK_SEL, 0x3)
> @@ -47,16 +48,23 @@
> #define IMX8MM_GPR_PCIE_SSC_EN BIT(16)
> #define IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE BIT(9)
>
> +enum imx8_pcie_phy_type {
> + IMX8MM,
> + IMX8MP,
> +};
> +
> struct imx8_pcie_phy {
> void __iomem *base;
> struct clk *clk;
> struct phy *phy;
> struct regmap *iomuxc_gpr;
> struct reset_control *reset;
> + struct reset_control *perst;
> u32 refclk_pad_mode;
> u32 tx_deemph_gen1;
> u32 tx_deemph_gen2;
> bool clkreq_unused;
> + enum imx8_pcie_phy_type variant;
> };
>
> static int imx8_pcie_phy_init(struct phy *phy)
> @@ -68,31 +76,20 @@ static int imx8_pcie_phy_init(struct phy *phy)
> reset_control_assert(imx8_phy->reset);
>
> pad_mode = imx8_phy->refclk_pad_mode;
> - /* Set AUX_EN_OVERRIDE 1'b0, when the CLKREQ# isn't hooked */
> - regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> - IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE,
> - imx8_phy->clkreq_unused ?
> - 0 : IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE);
> - regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> - IMX8MM_GPR_PCIE_AUX_EN,
> - IMX8MM_GPR_PCIE_AUX_EN);
> - regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> - IMX8MM_GPR_PCIE_POWER_OFF, 0);
> - regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> - IMX8MM_GPR_PCIE_SSC_EN, 0);
> -
> - regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> - IMX8MM_GPR_PCIE_REF_CLK_SEL,
> - pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT ?
> - IMX8MM_GPR_PCIE_REF_CLK_EXT :
> - IMX8MM_GPR_PCIE_REF_CLK_PLL);
> - usleep_range(100, 200);
> -
> - /* Do the PHY common block reset */
> - regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> - IMX8MM_GPR_PCIE_CMN_RST,
> - IMX8MM_GPR_PCIE_CMN_RST);
> - usleep_range(200, 500);
> + switch (imx8_phy->variant) {
> + case IMX8MM:
> + /* Tune PHY de-emphasis setting to pass PCIe compliance. */
> + if (imx8_phy->tx_deemph_gen1)
> + writel(imx8_phy->tx_deemph_gen1,
> + imx8_phy->base + PCIE_PHY_TRSV_REG5);
> + if (imx8_phy->tx_deemph_gen2)
> + writel(imx8_phy->tx_deemph_gen2,
> + imx8_phy->base + PCIE_PHY_TRSV_REG6);
> + break;
> + case IMX8MP:
> + reset_control_assert(imx8_phy->perst);
> + break;
> + }
>
> if (pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT ||
> pad_mode == IMX8_PCIE_REFCLK_PAD_UNUSED) {
> @@ -120,20 +117,44 @@ static int imx8_pcie_phy_init(struct phy *phy)
> imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG065);
> }
>
> - /* Tune PHY de-emphasis setting to pass PCIe compliance. */
> - if (imx8_phy->tx_deemph_gen1)
> - writel(imx8_phy->tx_deemph_gen1,
> - imx8_phy->base + PCIE_PHY_TRSV_REG5);
> - if (imx8_phy->tx_deemph_gen2)
> - writel(imx8_phy->tx_deemph_gen2,
> - imx8_phy->base + PCIE_PHY_TRSV_REG6);
> + /* Set AUX_EN_OVERRIDE 1'b0, when the CLKREQ# isn't hooked */
> + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> + IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE,
> + imx8_phy->clkreq_unused ?
> + 0 : IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE);
> + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> + IMX8MM_GPR_PCIE_AUX_EN,
> + IMX8MM_GPR_PCIE_AUX_EN);
> + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> + IMX8MM_GPR_PCIE_POWER_OFF, 0);
> + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> + IMX8MM_GPR_PCIE_SSC_EN, 0);
> +
> + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> + IMX8MM_GPR_PCIE_REF_CLK_SEL,
> + pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT ?
> + IMX8MM_GPR_PCIE_REF_CLK_EXT :
> + IMX8MM_GPR_PCIE_REF_CLK_PLL);
> + usleep_range(100, 200);
> +
> + /* Do the PHY common block reset */
> + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> + IMX8MM_GPR_PCIE_CMN_RST,
> + IMX8MM_GPR_PCIE_CMN_RST);
>
> - reset_control_deassert(imx8_phy->reset);
> + switch (imx8_phy->variant) {
> + case IMX8MP:
> + reset_control_deassert(imx8_phy->perst);
> + fallthrough;
> + case IMX8MM:
> + reset_control_deassert(imx8_phy->reset);
> + usleep_range(200, 500);
> + break;
> + }
>
> /* Polling to check the phy is ready or not. */
> - ret = readl_poll_timeout(imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG75,
> - val, val == PCIE_PHY_CMN_REG75_PLL_DONE,
> - 10, 20000);
> + ret = readl_poll_timeout(imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG075,
> + val, val == ANA_PLL_DONE, 10, 20000);
> return ret;
> }
>
> @@ -160,6 +181,13 @@ static const struct phy_ops imx8_pcie_phy_ops = {
> .owner = THIS_MODULE,
> };
>
> +static const struct of_device_id imx8_pcie_phy_of_match[] = {
> + {.compatible = "fsl,imx8mm-pcie-phy", .data = (void *)IMX8MM},
> + {.compatible = "fsl,imx8mp-pcie-phy", .data = (void *)IMX8MP},
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, imx8_pcie_phy_of_match);
> +
> static int imx8_pcie_phy_probe(struct platform_device *pdev)
> {
> struct phy_provider *phy_provider;
> @@ -172,6 +200,9 @@ static int imx8_pcie_phy_probe(struct platform_device *pdev)
> if (!imx8_phy)
> return -ENOMEM;
>
> + imx8_phy->variant =
> + (enum imx8_pcie_phy_type)of_device_get_match_data(dev);
> +
> /* get PHY refclk pad mode */
> of_property_read_u32(np, "fsl,refclk-pad-mode",
> &imx8_phy->refclk_pad_mode);
> @@ -196,8 +227,16 @@ static int imx8_pcie_phy_probe(struct platform_device *pdev)
> }
>
> /* Grab GPR config register range */
> - imx8_phy->iomuxc_gpr =
> - syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
> + switch (imx8_phy->variant) {
> + case IMX8MM:
> + imx8_phy->iomuxc_gpr =
> + syscon_regmap_lookup_by_compatible("fsl,imx8mm-iomuxc-gpr");
> + break;
> + case IMX8MP:
> + imx8_phy->iomuxc_gpr =
> + syscon_regmap_lookup_by_compatible("fsl,imx8mp-iomuxc-gpr");
> + break;
> + }

Oh, I had a real phandle in DT in mind for this, but I see how this
would be hard to introduce in a backward compatible manner for the 8MM.
At least this way it is fully contained in the driver and doesn't leak
into DT compatibles.

Maybe we could make this a little nicer by just having an const array
of iomux syscon compatibles indexed by imx8_phy->variant, to avoid the
switch and the resulting code (almost-)duplication.

Regards,
Lucas

> if (IS_ERR(imx8_phy->iomuxc_gpr)) {
> dev_err(dev, "unable to find iomuxc registers\n");
> return PTR_ERR(imx8_phy->iomuxc_gpr);
> @@ -208,6 +247,14 @@ static int imx8_pcie_phy_probe(struct platform_device *pdev)
> dev_err(dev, "Failed to get PCIEPHY reset control\n");
> return PTR_ERR(imx8_phy->reset);
> }
> + if (imx8_phy->variant == IMX8MP) {
> + imx8_phy->perst =
> + devm_reset_control_get_exclusive(dev, "perst");
> + if (IS_ERR(imx8_phy->perst)) {
> + dev_err(dev, "Failed to get PCIE PHY PERST control\n");
> + return PTR_ERR(imx8_phy->perst);
> + }
> + }
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> imx8_phy->base = devm_ioremap_resource(dev, res);
> @@ -225,12 +272,6 @@ static int imx8_pcie_phy_probe(struct platform_device *pdev)
> return PTR_ERR_OR_ZERO(phy_provider);
> }
>
> -static const struct of_device_id imx8_pcie_phy_of_match[] = {
> - {.compatible = "fsl,imx8mm-pcie-phy",},
> - { },
> -};
> -MODULE_DEVICE_TABLE(of, imx8_pcie_phy_of_match);
> -
> static struct platform_driver imx8_pcie_phy_driver = {
> .probe = imx8_pcie_phy_probe,
> .driver = {

Next message: Samuel Holland: "Re: [PATCH 1/3] dt-bindings: i2c: mv64xxx: Document DMA properties"
Previous message: Christian Dietrich: "Unexpected behavior: Sending signalfd over AF_UNIX"
In reply to: Richard Zhu: "[PATCH v5 6/7] phy: freescale: imx8m-pcie: Add iMX8MP PCIe PHY support"
Next in thread: Hongxing Zhu: "RE: [PATCH v5 6/7] phy: freescale: imx8m-pcie: Add iMX8MP PCIe PHY support"
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