Re: [PATCH v2 3/7] phy: freescale: imx8m-pcie: Add iMX8MP PCIe PHY support

From: Lucas Stach
Date: Tue Mar 08 2022 - 05:05:10 EST

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Hi Richard,

Am Montag, dem 07.03.2022 um 17:07 +0800 schrieb Richard Zhu:
> Add the i.MX8MP PCIe PHY support
>
> Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
> ---
> drivers/phy/freescale/phy-fsl-imx8m-pcie.c | 205 ++++++++++++++++-----
> 1 file changed, 163 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/phy/freescale/phy-fsl-imx8m-pcie.c b/drivers/phy/freescale/phy-fsl-imx8m-pcie.c
> index 04b1aafb29f4..3d01da4323a6 100644
> --- a/drivers/phy/freescale/phy-fsl-imx8m-pcie.c
> +++ b/drivers/phy/freescale/phy-fsl-imx8m-pcie.c
> @@ -11,6 +11,8 @@
> #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/phy/phy.h>
> #include <linux/platform_device.h>
> #include <linux/regmap.h>
> @@ -30,12 +32,10 @@
> #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)
> @@ -46,16 +46,43 @@
> #define IMX8MM_GPR_PCIE_SSC_EN BIT(16)
> #define IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE BIT(9)
>
> +#define IMX8MP_GPR_REG0 0x0
> +#define IMX8MP_GPR_CLK_MOD_EN BIT(0)
> +#define IMX8MP_GPR_PHY_APB_RST BIT(4)
> +#define IMX8MP_GPR_PHY_INIT_RST BIT(5)
> +#define IMX8MP_GPR_REG1 0x4
> +#define IMX8MP_GPR_PM_EN_CORE_CLK BIT(0)
> +#define IMX8MP_GPR_PLL_LOCK BIT(13)
> +#define IMX8MP_GPR_REG2 0x8
> +#define IMX8MP_GPR_P_PLL_MASK GENMASK(5, 0)
> +#define IMX8MP_GPR_M_PLL_MASK GENMASK(15, 6)
> +#define IMX8MP_GPR_S_PLL_MASK GENMASK(18, 16)
> +#define IMX8MP_GPR_P_PLL (0xc << 0)
> +#define IMX8MP_GPR_M_PLL (0x320 << 6)
> +#define IMX8MP_GPR_S_PLL (0x4 << 16)
> +#define IMX8MP_GPR_REG3 0xc
> +#define IMX8MP_GPR_PLL_CKE BIT(17)
> +#define IMX8MP_GPR_PLL_RST BIT(31)
> +
> +enum imx8_pcie_phy_type {
> + IMX8MM,
> + IMX8MP,
> +};
> +
> struct imx8_pcie_phy {
> void __iomem *base;
> + struct device *dev;
> struct clk *clk;
> struct phy *phy;
> + struct regmap *hsio_blk_ctrl;
> 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)
> @@ -67,6 +94,87 @@ static int imx8_pcie_phy_init(struct phy *phy)
> reset_control_assert(imx8_phy->reset);
>
> pad_mode = imx8_phy->refclk_pad_mode;
> + 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);
> + /* Set P=12,M=800,S=4 and must set ICP=2'b01. */
> + regmap_update_bits(imx8_phy->hsio_blk_ctrl, IMX8MP_GPR_REG2,
> + IMX8MP_GPR_P_PLL_MASK |
> + IMX8MP_GPR_M_PLL_MASK |
> + IMX8MP_GPR_S_PLL_MASK,
> + IMX8MP_GPR_P_PLL |
> + IMX8MP_GPR_M_PLL |
> + IMX8MP_GPR_S_PLL);
> + /* wait greater than 1/F_FREF =1/2MHZ=0.5us */
> + udelay(1);
> +
> + regmap_update_bits(imx8_phy->hsio_blk_ctrl, IMX8MP_GPR_REG3,
> + IMX8MP_GPR_PLL_RST,
> + IMX8MP_GPR_PLL_RST);
> + udelay(10);
> +
> + /* Set 1 to pll_cke of GPR_REG3 */
> + regmap_update_bits(imx8_phy->hsio_blk_ctrl, IMX8MP_GPR_REG3,
> + IMX8MP_GPR_PLL_CKE,
> + IMX8MP_GPR_PLL_CKE);
> +
> + /* Lock time should be greater than 300cycle=300*0.5us=150us */
> + ret = regmap_read_poll_timeout(imx8_phy->hsio_blk_ctrl,
> + IMX8MP_GPR_REG1, val,
> + val & IMX8MP_GPR_PLL_LOCK,
> + 10, 1000);
> + if (ret) {
> + dev_err(imx8_phy->dev, "PCIe PLL lock timeout\n");
> + return ret;
> + }

As far as I understand the reference manual, this PLL is not exclusive
to the PCIe core, but can be used as a alternate reference clock for
the USB PHYs. I think we should not poke the PLL registers from the
PCIe PHY driver, but should make this PLL a real clock provided by the
HSIO blk-ctrl.

It's probably a good prove of concept for other clocks that need to be
provided by the blk-ctrls, as the audio blk-ctrl has much more of this
secondary clock controller functionality.

Do you want to give it a shot at integrating this into the blk-ctrl
driver, or should I take a look?

Regards,
Lucas

> +
> + /* pcie_clock_module_en */
> + regmap_update_bits(imx8_phy->hsio_blk_ctrl, IMX8MP_GPR_REG0,
> + IMX8MP_GPR_CLK_MOD_EN,
> + IMX8MP_GPR_CLK_MOD_EN);
> + udelay(10);
> +
> + reset_control_deassert(imx8_phy->reset);
> + reset_control_deassert(imx8_phy->perst);
> +
> + /* release pcie_phy_apb_reset and pcie_phy_init_resetn */
> + regmap_update_bits(imx8_phy->hsio_blk_ctrl, IMX8MP_GPR_REG0,
> + IMX8MP_GPR_PHY_APB_RST |
> + IMX8MP_GPR_PHY_INIT_RST,
> + IMX8MP_GPR_PHY_APB_RST |
> + IMX8MP_GPR_PHY_INIT_RST);
> + break;
> + }
> +
> + if (pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT) {
> + /* Configure the pad as input */
> + val = readl(imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061);
> + writel(val & ~ANA_PLL_CLK_OUT_TO_EXT_IO_EN,
> + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061);
> + } else if (pad_mode == IMX8_PCIE_REFCLK_PAD_OUTPUT) {
> + /* Configure the PHY to output the refclock via pad */
> + writel(ANA_PLL_CLK_OUT_TO_EXT_IO_EN,
> + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061);
> + writel(ANA_PLL_CLK_OUT_TO_EXT_IO_SEL,
> + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG062);
> + writel(AUX_PLL_REFCLK_SEL_SYS_PLL,
> + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG063);
> + val = ANA_AUX_RX_TX_SEL_TX | ANA_AUX_TX_TERM;
> + writel(val | ANA_AUX_RX_TERM_GND_EN,
> + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG064);
> + writel(ANA_AUX_RX_TERM | ANA_AUX_TX_LVL,
> + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG065);
> + }
> +
> /* 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,
> @@ -91,42 +199,30 @@ static int imx8_pcie_phy_init(struct phy *phy)
> regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
> IMX8MM_GPR_PCIE_CMN_RST,
> IMX8MM_GPR_PCIE_CMN_RST);
> - usleep_range(200, 500);
>
> - if (pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT) {
> - /* Configure the pad as input */
> - val = readl(imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061);
> - writel(val & ~ANA_PLL_CLK_OUT_TO_EXT_IO_EN,
> - imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061);
> - } else if (pad_mode == IMX8_PCIE_REFCLK_PAD_OUTPUT) {
> - /* Configure the PHY to output the refclock via pad */
> - writel(ANA_PLL_CLK_OUT_TO_EXT_IO_EN,
> - imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061);
> - writel(ANA_PLL_CLK_OUT_TO_EXT_IO_SEL,
> - imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG062);
> - writel(AUX_PLL_REFCLK_SEL_SYS_PLL,
> - imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG063);
> - val = ANA_AUX_RX_TX_SEL_TX | ANA_AUX_TX_TERM;
> - writel(val | ANA_AUX_RX_TERM_GND_EN,
> - imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG064);
> - writel(ANA_AUX_RX_TERM | ANA_AUX_TX_LVL,
> - imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG065);
> + switch (imx8_phy->variant) {
> + case IMX8MM:
> + reset_control_deassert(imx8_phy->reset);
> + usleep_range(200, 500);
> + break;
> +
> + case IMX8MP:
> + /* wait for core_clk enabled */
> + ret = regmap_read_poll_timeout(imx8_phy->hsio_blk_ctrl,
> + IMX8MP_GPR_REG1, val,
> + val & IMX8MP_GPR_PM_EN_CORE_CLK,
> + 10, 20000);
> + if (ret) {
> + dev_err(imx8_phy->dev, "PCIe CORE CLK enable failed\n");
> + return ret;
> + }
> +
> + break;
> }
>
> - /* 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);
> -
> - reset_control_deassert(imx8_phy->reset);
> -
> /* 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;
> }
>
> @@ -153,18 +249,33 @@ 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;
> struct device *dev = &pdev->dev;
> + const struct of_device_id *of_id;
> struct device_node *np = dev->of_node;
> struct imx8_pcie_phy *imx8_phy;
> struct resource *res;
>
> + of_id = of_match_device(imx8_pcie_phy_of_match, dev);
> + if (!of_id)
> + return -EINVAL;
> +
> imx8_phy = devm_kzalloc(dev, sizeof(*imx8_phy), GFP_KERNEL);
> if (!imx8_phy)
> return -ENOMEM;
>
> + imx8_phy->dev = dev;
> + imx8_phy->variant = (enum imx8_pcie_phy_type)of_id->data;
> +
> /* get PHY refclk pad mode */
> of_property_read_u32(np, "fsl,refclk-pad-mode",
> &imx8_phy->refclk_pad_mode);
> @@ -201,6 +312,22 @@ 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) {
> + /* Grab HSIO MIX config register range */
> + imx8_phy->hsio_blk_ctrl =
> + syscon_regmap_lookup_by_compatible("fsl,imx8mp-hsio-blk-ctrl");
> + if (IS_ERR(imx8_phy->hsio_blk_ctrl)) {
> + dev_err(dev, "unable to find hsio mix registers\n");
> + return PTR_ERR(imx8_phy->hsio_blk_ctrl);
> + }
> +
> + imx8_phy->perst =
> + devm_reset_control_get_exclusive(dev, "perst");
> + if (IS_ERR(imx8_phy->perst)) {
> + dev_err(dev, "Failed to get PCIEPHY 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);
> @@ -218,12 +345,6 @@ 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 = {

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Previous message: Andy Shevchenko: "Re: [PATCH] gpio: sim: fix a typo"
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