[PATCH v6 5/8] phy: freescale: pcie: Initialize the imx8 pcie standalone phy driver

Richard Zhu
2021-11-18T02:21:56Z

Add the standalone i.MX8 PCIe PHY driver.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Tim Harvey <tharvey@gateworks.com>
Tested-by: Tim Harvey <tharvey@gateworks.com>
---
drivers/phy/freescale/Kconfig | 9 +
drivers/phy/freescale/Makefile | 1 +
drivers/phy/freescale/phy-fsl-imx8m-pcie.c | 237 +++++++++++++++++++++
3 files changed, 247 insertions(+)
create mode 100644 drivers/phy/freescale/phy-fsl-imx8m-pcie.c

diff --git a/drivers/phy/freescale/Kconfig b/drivers/phy/freescale/Kconfig
index 320630ffe3cd..e821498b1f7f 100644
--- a/drivers/phy/freescale/Kconfig
+++ b/drivers/phy/freescale/Kconfig
@@ -14,3 +14,12 @@ config PHY_MIXEL_MIPI_DPHY
help
Enable this to add support for the Mixel DSI PHY as found
on NXP's i.MX8 family of SOCs.
+
+config PHY_FSL_IMX8M_PCIE
+ tristate "Freescale i.MX8M PCIE PHY"
+ depends on OF && HAS_IOMEM
+ select GENERIC_PHY
+ default ARCH_MXC && ARM64
+ help
+ Enable this to add support for the PCIE PHY as found on
+ i.MX8M family of SOCs.
diff --git a/drivers/phy/freescale/Makefile b/drivers/phy/freescale/Makefile
index 1d02e3869b45..55d07c742ab0 100644
--- a/drivers/phy/freescale/Makefile
+++ b/drivers/phy/freescale/Makefile
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_PHY_FSL_IMX8MQ_USB) += phy-fsl-imx8mq-usb.o
obj-$(CONFIG_PHY_MIXEL_MIPI_DPHY) += phy-fsl-imx8-mipi-dphy.o
+obj-$(CONFIG_PHY_FSL_IMX8M_PCIE) += phy-fsl-imx8m-pcie.o
diff --git a/drivers/phy/freescale/phy-fsl-imx8m-pcie.c b/drivers/phy/freescale/phy-fsl-imx8m-pcie.c
new file mode 100644
index 000000000000..357483a7efeb
--- /dev/null
+++ b/drivers/phy/freescale/phy-fsl-imx8m-pcie.c
@@ -0,0 +1,237 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2021 NXP
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/delay.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/imx7-iomuxc-gpr.h>
+#include <linux/module.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/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_REG75 0x1D4
+#define PCIE_PHY_CMN_REG75_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)
+#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)
+
+struct imx8_pcie_phy {
+ void __iomem *base;
+ struct clk *clk;
+ struct phy *phy;
+ struct regmap *iomuxc_gpr;
+ struct reset_control *reset;
+ u32 refclk_pad_mode;
+ u32 tx_deemph_gen1;
+ u32 tx_deemph_gen2;
+ bool clkreq_unused;
+};
+
+static int imx8_pcie_phy_init(struct phy *phy)
+{
+ int ret;
+ u32 val, pad_mode;
+ struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(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);
+
+
+ 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);
+ }
+
+ /* 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);
+ return ret;
+}
+
+static int imx8_pcie_phy_power_on(struct phy *phy)
+{
+ struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy);
+
+ return clk_prepare_enable(imx8_phy->clk);
+}
+
+static int imx8_pcie_phy_power_off(struct phy *phy)
+{
+ struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy);
+
+ clk_disable_unprepare(imx8_phy->clk);
+
+ return 0;
+}
+
+static const struct phy_ops imx8_pcie_phy_ops = {
+ .init = imx8_pcie_phy_init,
+ .power_on = imx8_pcie_phy_power_on,
+ .power_off = imx8_pcie_phy_power_off,
+ .owner = THIS_MODULE,
+};
+
+static int imx8_pcie_phy_probe(struct platform_device *pdev)
+{
+ struct phy_provider *phy_provider;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct imx8_pcie_phy *imx8_phy;
+ struct resource *res;
+
+ imx8_phy = devm_kzalloc(dev, sizeof(*imx8_phy), GFP_KERNEL);
+ if (!imx8_phy)
+ return -ENOMEM;
+
+ /* get PHY refclk pad mode */
+ of_property_read_u32(np, "fsl,refclk-pad-mode",
+ &imx8_phy->refclk_pad_mode);
+
+ if (of_property_read_u32(np, "fsl,tx-deemph-gen1",
+ &imx8_phy->tx_deemph_gen1))
+ imx8_phy->tx_deemph_gen1 = 0;
+
+ if (of_property_read_u32(np, "fsl,tx-deemph-gen2",
+ &imx8_phy->tx_deemph_gen2))
+ imx8_phy->tx_deemph_gen2 = 0;
+
+ if (of_property_read_bool(np, "fsl,clkreq-unsupported"))
+ imx8_phy->clkreq_unused = true;
+ else
+ imx8_phy->clkreq_unused = false;
+
+ imx8_phy->clk = devm_clk_get(dev, "ref");
+ if (IS_ERR(imx8_phy->clk)) {
+ dev_err(dev, "failed to get imx pcie phy clock\n");
+ return PTR_ERR(imx8_phy->clk);
+ }
+
+ /* Grab GPR config register range */
+ imx8_phy->iomuxc_gpr =
+ syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
+ if (IS_ERR(imx8_phy->iomuxc_gpr)) {
+ dev_err(dev, "unable to find iomuxc registers\n");
+ return PTR_ERR(imx8_phy->iomuxc_gpr);
+ }
+
+ imx8_phy->reset = devm_reset_control_get_exclusive(dev, "pciephy");
+ if (IS_ERR(imx8_phy->reset)) {
+ dev_err(dev, "Failed to get PCIEPHY reset control\n");
+ return PTR_ERR(imx8_phy->reset);
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ imx8_phy->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(imx8_phy->base))
+ return PTR_ERR(imx8_phy->base);
+
+ imx8_phy->phy = devm_phy_create(dev, NULL, &imx8_pcie_phy_ops);
+ if (IS_ERR(imx8_phy->phy))
+ return PTR_ERR(imx8_phy->phy);
+
+ phy_set_drvdata(imx8_phy->phy, imx8_phy);
+
+ phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+ 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 = {
+ .name = "imx8-pcie-phy",
+ .of_match_table = imx8_pcie_phy_of_match,
+ }
+};
+module_platform_driver(imx8_pcie_phy_driver);
+
+MODULE_DESCRIPTION("FSL IMX8 PCIE PHY driver");
+MODULE_LICENSE("GPL");
--
2.25.1