phy: phy-imx8m-pcie: Add support for i.MX8M{M/P} PCIe PHY
Add initial support for i.MX8M{M/P} PCIe PHY. On i.MX8M{M/P} SoCs PCIe
PHY initialization moved to this standalone PHY driver.
Inspired from counterpart Linux kernel v6.8-rc3 driver:
drivers/phy/freescale/phy-fsl-imx8m-pcie.c. Use last Linux kernel driver
reference commit 7559e7572c03 ("phy: Explicitly include correct DT
includes").
Tested-by: Tim Harvey <tharvey@gateworks.com> #imx8mp-venice*
Tested-by: Adam Ford <aford173@gmail.com> #imx8mp-beacon-kit
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 60138be..8f76787 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -284,6 +284,17 @@
help
Support the USB3.0 PHY in NXP i.MX8MQ or i.MX8MP SoC
+config PHY_IMX8M_PCIE
+ bool "NXP i.MX8MM/i.MX8MP PCIe PHY Driver"
+ depends on PHY
+ depends on IMX8MM || IMX8MP
+ select REGMAP
+ select SYSCON
+ help
+ Support the PCIe PHY in NXP i.MX8MM or i.MX8MP SoC
+
+ This PHY is found on i.MX8M devices supporting PCIe.
+
config PHY_XILINX_ZYNQMP
tristate "Xilinx ZynqMP PHY driver"
depends on PHY && ARCH_ZYNQMP
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 2e87231..7a2b764 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -38,6 +38,7 @@
obj-$(CONFIG_PHY_MTK_TPHY) += phy-mtk-tphy.o
obj-$(CONFIG_PHY_NPCM_USB) += phy-npcm-usb.o
obj-$(CONFIG_PHY_IMX8MQ_USB) += phy-imx8mq-usb.o
+obj-$(CONFIG_PHY_IMX8M_PCIE) += phy-imx8m-pcie.o
obj-$(CONFIG_PHY_XILINX_ZYNQMP) += phy-zynqmp.o
obj-y += cadence/
obj-y += ti/
diff --git a/drivers/phy/phy-imx8m-pcie.c b/drivers/phy/phy-imx8m-pcie.c
new file mode 100644
index 0000000..2418388
--- /dev/null
+++ b/drivers/phy/phy-imx8m-pcie.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2024 Linaro Ltd.
+ *
+ * Derived from Linux counterpart driver
+ */
+
+#include <asm/io.h>
+#include <clk.h>
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <generic-phy.h>
+#include <linux/bitfield.h>
+#include <linux/clk-provider.h>
+#include <linux/iopoll.h>
+#include <syscon.h>
+#include <regmap.h>
+#include <reset.h>
+
+#include <dt-bindings/phy/phy-imx8-pcie.h>
+
+#define IMX8MM_PCIE_PHY_CMN_REG061 0x184
+#define ANA_PLL_CLK_OUT_TO_EXT_IO_EN BIT(0)
+#define IMX8MM_PCIE_PHY_CMN_REG062 0x188
+#define ANA_PLL_CLK_OUT_TO_EXT_IO_SEL BIT(3)
+#define IMX8MM_PCIE_PHY_CMN_REG063 0x18C
+#define AUX_PLL_REFCLK_SEL_SYS_PLL GENMASK(7, 6)
+#define IMX8MM_PCIE_PHY_CMN_REG064 0x190
+#define ANA_AUX_RX_TX_SEL_TX BIT(7)
+#define ANA_AUX_RX_TERM_GND_EN BIT(3)
+#define ANA_AUX_TX_TERM BIT(2)
+#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_REG075 0x1D4
+#define ANA_PLL_DONE 0x3
+#define PCIE_PHY_TRSV_REG5 0x414
+#define PCIE_PHY_TRSV_REG6 0x418
+
+#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)
+#define IMX8MM_GPR_PCIE_REF_CLK_EXT FIELD_PREP(IMX8MM_GPR_PCIE_REF_CLK_SEL, 0x2)
+#define IMX8MM_GPR_PCIE_AUX_EN BIT(19)
+#define IMX8MM_GPR_PCIE_CMN_RST BIT(18)
+#define IMX8MM_GPR_PCIE_POWER_OFF BIT(17)
+#define IMX8MM_GPR_PCIE_SSC_EN BIT(16)
+#define IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE BIT(9)
+
+#define IOMUXC_GPR14_OFFSET 0x38
+
+enum imx8_pcie_phy_type {
+ IMX8MM,
+ IMX8MP,
+};
+
+struct imx8_pcie_phy_drvdata {
+ const char *gpr;
+ enum imx8_pcie_phy_type variant;
+};
+
+struct imx8_pcie_phy {
+ ulong base;
+ struct clk hsio_clk;
+ struct regmap *iomuxc_gpr;
+ struct reset_ctl perst;
+ struct reset_ctl reset;
+ u32 refclk_pad_mode;
+ u32 tx_deemph_gen1;
+ u32 tx_deemph_gen2;
+ bool clkreq_unused;
+ const struct imx8_pcie_phy_drvdata *drvdata;
+};
+
+static int imx8_pcie_phy_power_on(struct phy *phy)
+{
+ int ret;
+ u32 val, pad_mode;
+ struct imx8_pcie_phy *imx8_phy = dev_get_priv(phy->dev);
+
+ pad_mode = imx8_phy->refclk_pad_mode;
+ switch (imx8_phy->drvdata->variant) {
+ case IMX8MM:
+ reset_assert(&imx8_phy->reset);
+
+ /* 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: /* Do nothing. */
+ break;
+ }
+
+ if (pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT ||
+ pad_mode == IMX8_PCIE_REFCLK_PAD_UNUSED) {
+ /* 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 {
+ /* 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);
+ }
+
+ if (pad_mode == IMX8_PCIE_REFCLK_PAD_OUTPUT ||
+ pad_mode == IMX8_PCIE_REFCLK_PAD_UNUSED) {
+ /* Source clock from SoC internal PLL */
+ 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_OFFSET,
+ 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_OFFSET,
+ IMX8MM_GPR_PCIE_AUX_EN,
+ IMX8MM_GPR_PCIE_AUX_EN);
+ regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14_OFFSET,
+ IMX8MM_GPR_PCIE_POWER_OFF, 0);
+ regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14_OFFSET,
+ IMX8MM_GPR_PCIE_SSC_EN, 0);
+
+ regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14_OFFSET,
+ 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);
+ udelay(200);
+
+ /* Do the PHY common block reset */
+ regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14_OFFSET,
+ IMX8MM_GPR_PCIE_CMN_RST,
+ IMX8MM_GPR_PCIE_CMN_RST);
+
+ switch (imx8_phy->drvdata->variant) {
+ case IMX8MP:
+ reset_deassert(&imx8_phy->perst);
+ fallthrough;
+ case IMX8MM:
+ reset_deassert(&imx8_phy->reset);
+ udelay(500);
+ break;
+ }
+
+ /* Polling to check the phy is ready or not. */
+ ret = readl_poll_timeout(imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG075,
+ val, val == ANA_PLL_DONE, 20000);
+ return ret;
+}
+
+static int imx8_pcie_phy_init(struct phy *phy)
+{
+ struct imx8_pcie_phy *imx8_phy = dev_get_priv(phy->dev);
+
+ return clk_enable(&imx8_phy->hsio_clk);
+}
+
+static int imx8_pcie_phy_exit(struct phy *phy)
+{
+ struct imx8_pcie_phy *imx8_phy = dev_get_priv(phy->dev);
+
+ return clk_disable(&imx8_phy->hsio_clk);
+}
+
+static const struct phy_ops imx8_pcie_phy_ops = {
+ .init = imx8_pcie_phy_init,
+ .exit = imx8_pcie_phy_exit,
+ .power_on = imx8_pcie_phy_power_on,
+};
+
+static const struct imx8_pcie_phy_drvdata imx8mm_drvdata = {
+ .gpr = "fsl,imx8mm-iomuxc-gpr",
+ .variant = IMX8MM,
+};
+
+static const struct imx8_pcie_phy_drvdata imx8mp_drvdata = {
+ .gpr = "fsl,imx8mp-iomuxc-gpr",
+ .variant = IMX8MP,
+};
+
+static const struct udevice_id imx8_pcie_phy_of_match[] = {
+ {.compatible = "fsl,imx8mm-pcie-phy", .data = (ulong)&imx8mm_drvdata, },
+ {.compatible = "fsl,imx8mp-pcie-phy", .data = (ulong)&imx8mp_drvdata, },
+ { },
+};
+
+static int imx8_pcie_phy_probe(struct udevice *dev)
+{
+ struct imx8_pcie_phy *imx8_phy = dev_get_priv(dev);
+ ofnode gpr;
+ int ret = 0;
+
+ imx8_phy->drvdata = (void *)dev_get_driver_data(dev);
+ imx8_phy->base = dev_read_addr(dev);
+ if (!imx8_phy->base)
+ return -EINVAL;
+
+ /* get PHY refclk pad mode */
+ dev_read_u32(dev, "fsl,refclk-pad-mode", &imx8_phy->refclk_pad_mode);
+
+ imx8_phy->tx_deemph_gen1 = dev_read_u32_default(dev,
+ "fsl,tx-deemph-gen1",
+ 0);
+ imx8_phy->tx_deemph_gen2 = dev_read_u32_default(dev,
+ "fsl,tx-deemph-gen2",
+ 0);
+ imx8_phy->clkreq_unused = dev_read_bool(dev, "fsl,clkreq-unsupported");
+
+ /* Grab GPR config register range */
+ gpr = ofnode_by_compatible(ofnode_null(), imx8_phy->drvdata->gpr);
+ if (ofnode_equal(gpr, ofnode_null())) {
+ dev_err(dev, "unable to find GPR node\n");
+ return -ENODEV;
+ }
+
+ imx8_phy->iomuxc_gpr = syscon_node_to_regmap(gpr);
+ if (IS_ERR(imx8_phy->iomuxc_gpr)) {
+ dev_err(dev, "unable to find iomuxc registers\n");
+ return PTR_ERR(imx8_phy->iomuxc_gpr);
+ }
+
+ ret = clk_get_by_name(dev, "ref", &imx8_phy->hsio_clk);
+ if (ret) {
+ dev_err(dev, "Failed to get PCIEPHY ref clock\n");
+ return ret;
+ }
+
+ ret = reset_get_by_name(dev, "pciephy", &imx8_phy->reset);
+ if (ret) {
+ dev_err(dev, "Failed to get PCIEPHY reset control\n");
+ return ret;
+ }
+
+ if (imx8_phy->drvdata->variant == IMX8MP) {
+ ret = reset_get_by_name(dev, "perst", &imx8_phy->perst);
+ if (ret) {
+ dev_err(dev,
+ "Failed to get PCIEPHY PHY PERST control\n");
+ goto err_perst;
+ }
+ }
+
+ return 0;
+
+err_perst:
+ reset_free(&imx8_phy->reset);
+ return ret;
+}
+
+static int imx8_pcie_phy_remove(struct udevice *dev)
+{
+ struct imx8_pcie_phy *imx8_phy = dev_get_priv(dev);
+
+ if (imx8_phy->drvdata->variant == IMX8MP)
+ reset_free(&imx8_phy->perst);
+
+ reset_free(&imx8_phy->reset);
+
+ return 0;
+}
+
+U_BOOT_DRIVER(nxp_imx8_pcie_phy) = {
+ .name = "nxp_imx8_pcie_phy",
+ .id = UCLASS_PHY,
+ .of_match = imx8_pcie_phy_of_match,
+ .probe = imx8_pcie_phy_probe,
+ .remove = imx8_pcie_phy_remove,
+ .ops = &imx8_pcie_phy_ops,
+ .priv_auto = sizeof(struct imx8_pcie_phy),
+};