[PATCH v9 2/2] phy: mediatek: Add PCIe PHY driver

Jianjun Wang
2022-05-20T06:49:56Z

Add PCIe GEN3 PHY driver support on MediaTek chipsets.

Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
---
drivers/phy/mediatek/Kconfig | 11 ++
drivers/phy/mediatek/Makefile | 1 +
drivers/phy/mediatek/phy-mtk-pcie.c | 267 ++++++++++++++++++++++++++++
3 files changed, 279 insertions(+)
create mode 100644 drivers/phy/mediatek/phy-mtk-pcie.c

diff --git a/drivers/phy/mediatek/Kconfig b/drivers/phy/mediatek/Kconfig
index 55f8e6c048ab..387ed1b3f2cc 100644
--- a/drivers/phy/mediatek/Kconfig
+++ b/drivers/phy/mediatek/Kconfig
@@ -55,3 +55,14 @@ config PHY_MTK_MIPI_DSI
select GENERIC_PHY
help
Support MIPI DSI for Mediatek SoCs.
+
+config PHY_MTK_PCIE
+ tristate "MediaTek PCIe-PHY Driver"
+ depends on ARCH_MEDIATEK || COMPILE_TEST
+ depends on OF
+ select GENERIC_PHY
+ help
+ Say 'Y' here to add support for MediaTek PCIe PHY driver.
+ This driver create the basic PHY instance and provides initialize
+ callback for PCIe GEN3 port, it supports software efuse
+ initialization.
diff --git a/drivers/phy/mediatek/Makefile b/drivers/phy/mediatek/Makefile
index ace660fbed3a..788c13147f63 100644
--- a/drivers/phy/mediatek/Makefile
+++ b/drivers/phy/mediatek/Makefile
@@ -6,6 +6,7 @@
obj-$(CONFIG_PHY_MTK_TPHY) += phy-mtk-tphy.o
obj-$(CONFIG_PHY_MTK_UFS) += phy-mtk-ufs.o
obj-$(CONFIG_PHY_MTK_XSPHY) += phy-mtk-xsphy.o
+obj-$(CONFIG_PHY_MTK_PCIE) += phy-mtk-pcie.o

phy-mtk-hdmi-drv-y := phy-mtk-hdmi.o
phy-mtk-hdmi-drv-y += phy-mtk-hdmi-mt2701.o
diff --git a/drivers/phy/mediatek/phy-mtk-pcie.c b/drivers/phy/mediatek/phy-mtk-pcie.c
new file mode 100644
index 000000000000..7f29d43442bf
--- /dev/null
+++ b/drivers/phy/mediatek/phy-mtk-pcie.c
@@ -0,0 +1,267 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2022 MediaTek Inc.
+ * Author: Jianjun Wang <jianjun.wang@mediatek.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/of_device.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "phy-mtk-io.h"
+
+#define PEXTP_ANA_GLB_00_REG 0x9000
+/* Internal Resistor Selection of TX Bias Current */
+#define EFUSE_GLB_INTR_SEL GENMASK(28, 24)
+
+#define PEXTP_ANA_LN0_TRX_REG 0xa000
+
+#define PEXTP_ANA_TX_REG 0x04
+/* TX PMOS impedance selection */
+#define EFUSE_LN_TX_PMOS_SEL GENMASK(5, 2)
+/* TX NMOS impedance selection */
+#define EFUSE_LN_TX_NMOS_SEL GENMASK(11, 8)
+
+#define PEXTP_ANA_RX_REG 0x3c
+/* RX impedance selection */
+#define EFUSE_LN_RX_SEL GENMASK(3, 0)
+
+#define PEXTP_ANA_LANE_OFFSET 0x100
+
+/**
+ * struct mtk_pcie_lane_efuse - eFuse data for each lane
+ * @tx_pmos: TX PMOS impedance selection data
+ * @tx_nmos: TX NMOS impedance selection data
+ * @rx_data: RX impedance selection data
+ * @lane_efuse_supported: software eFuse data is supported for this lane
+ */
+struct mtk_pcie_lane_efuse {
+ u32 tx_pmos;
+ u32 tx_nmos;
+ u32 rx_data;
+ bool lane_efuse_supported;
+};
+
+/**
+ * struct mtk_pcie_phy_data - phy data for each SoC
+ * @num_lanes: supported lane numbers
+ * @sw_efuse_supported: support software to load eFuse data
+ */
+struct mtk_pcie_phy_data {
+ int num_lanes;
+ bool sw_efuse_supported;
+};
+
+/**
+ * struct mtk_pcie_phy - PCIe phy driver main structure
+ * @dev: pointer to device
+ * @phy: pointer to generic phy
+ * @sif_base: IO mapped register base address of system interface
+ * @data: pointer to SoC dependent data
+ * @sw_efuse_en: software eFuse enable status
+ * @efuse_glb_intr: internal resistor selection of TX bias current data
+ * @efuse: pointer to eFuse data for each lane
+ */
+struct mtk_pcie_phy {
+ struct device *dev;
+ struct phy *phy;
+ void __iomem *sif_base;
+ const struct mtk_pcie_phy_data *data;
+
+ bool sw_efuse_en;
+ u32 efuse_glb_intr;
+ struct mtk_pcie_lane_efuse *efuse;
+};
+
+static void mtk_pcie_efuse_set_lane(struct mtk_pcie_phy *pcie_phy,
+ unsigned int lane)
+{
+ struct mtk_pcie_lane_efuse *data = &pcie_phy->efuse[lane];
+ void __iomem *addr;
+
+ if (!data->lane_efuse_supported)
+ return;
+
+ addr = pcie_phy->sif_base + PEXTP_ANA_LN0_TRX_REG +
+ lane * PEXTP_ANA_LANE_OFFSET;
+
+ mtk_phy_update_bits(addr + PEXTP_ANA_TX_REG, EFUSE_LN_TX_PMOS_SEL,
+ FIELD_PREP(EFUSE_LN_TX_PMOS_SEL, data->tx_pmos));
+
+ mtk_phy_update_bits(addr + PEXTP_ANA_TX_REG, EFUSE_LN_TX_NMOS_SEL,
+ FIELD_PREP(EFUSE_LN_TX_NMOS_SEL, data->tx_nmos));
+
+ mtk_phy_update_bits(addr + PEXTP_ANA_RX_REG, EFUSE_LN_RX_SEL,
+ FIELD_PREP(EFUSE_LN_RX_SEL, data->rx_data));
+}
+
+/**
+ * mtk_pcie_phy_init() - Initialize the phy
+ * @phy: the phy to be initialized
+ *
+ * Initialize the phy by setting the efuse data.
+ * The hardware settings will be reset during suspend, it should be
+ * reinitialized when the consumer calls phy_init() again on resume.
+ */
+static int mtk_pcie_phy_init(struct phy *phy)
+{
+ struct mtk_pcie_phy *pcie_phy = phy_get_drvdata(phy);
+ int i;
+
+ if (!pcie_phy->sw_efuse_en)
+ return 0;
+
+ /* Set global data */
+ mtk_phy_update_bits(pcie_phy->sif_base + PEXTP_ANA_GLB_00_REG,
+ EFUSE_GLB_INTR_SEL,
+ FIELD_PREP(EFUSE_GLB_INTR_SEL, pcie_phy->efuse_glb_intr));
+
+ for (i = 0; i < pcie_phy->data->num_lanes; i++)
+ mtk_pcie_efuse_set_lane(pcie_phy, i);
+
+ return 0;
+}
+
+static const struct phy_ops mtk_pcie_phy_ops = {
+ .init = mtk_pcie_phy_init,
+ .owner = THIS_MODULE,
+};
+
+static int mtk_pcie_efuse_read_for_lane(struct mtk_pcie_phy *pcie_phy,
+ unsigned int lane)
+{
+ struct mtk_pcie_lane_efuse *efuse = &pcie_phy->efuse[lane];
+ struct device *dev = pcie_phy->dev;
+ char efuse_id[16];
+ int ret;
+
+ snprintf(efuse_id, sizeof(efuse_id), "tx_ln%d_pmos", lane);
+ ret = nvmem_cell_read_variable_le_u32(dev, efuse_id, &efuse->tx_pmos);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to read %s\n", efuse_id);
+
+ snprintf(efuse_id, sizeof(efuse_id), "tx_ln%d_nmos", lane);
+ ret = nvmem_cell_read_variable_le_u32(dev, efuse_id, &efuse->tx_nmos);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to read %s\n", efuse_id);
+
+ snprintf(efuse_id, sizeof(efuse_id), "rx_ln%d", lane);
+ ret = nvmem_cell_read_variable_le_u32(dev, efuse_id, &efuse->rx_data);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to read %s\n", efuse_id);
+
+ if (!(efuse->tx_pmos || efuse->tx_nmos || efuse->rx_data))
+ return dev_err_probe(dev, -EINVAL,
+ "No eFuse data found for lane%d, but dts enable it\n",
+ lane);
+
+ efuse->lane_efuse_supported = true;
+
+ return 0;
+}
+
+static int mtk_pcie_read_efuse(struct mtk_pcie_phy *pcie_phy)
+{
+ struct device *dev = pcie_phy->dev;
+ bool nvmem_enabled;
+ int ret, i;
+
+ /* nvmem data is optional */
+ nvmem_enabled = device_property_present(dev, "nvmem-cells");
+ if (!nvmem_enabled)
+ return 0;
+
+ ret = nvmem_cell_read_variable_le_u32(dev, "glb_intr",
+ &pcie_phy->efuse_glb_intr);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to read glb_intr\n");
+
+ pcie_phy->sw_efuse_en = true;
+
+ pcie_phy->efuse = devm_kzalloc(dev, pcie_phy->data->num_lanes *
+ sizeof(*pcie_phy->efuse), GFP_KERNEL);
+ if (!pcie_phy->efuse)
+ return -ENOMEM;
+
+ for (i = 0; i < pcie_phy->data->num_lanes; i++) {
+ ret = mtk_pcie_efuse_read_for_lane(pcie_phy, i);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int mtk_pcie_phy_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct phy_provider *provider;
+ struct mtk_pcie_phy *pcie_phy;
+ int ret;
+
+ pcie_phy = devm_kzalloc(dev, sizeof(*pcie_phy), GFP_KERNEL);
+ if (!pcie_phy)
+ return -ENOMEM;
+
+ pcie_phy->sif_base = devm_platform_ioremap_resource_byname(pdev, "sif");
+ if (IS_ERR(pcie_phy->sif_base))
+ return dev_err_probe(dev, PTR_ERR(pcie_phy->sif_base),
+ "Failed to map phy-sif base\n");
+
+ pcie_phy->phy = devm_phy_create(dev, dev->of_node, &mtk_pcie_phy_ops);
+ if (IS_ERR(pcie_phy->phy))
+ return dev_err_probe(dev, PTR_ERR(pcie_phy->phy),
+ "Failed to create PCIe phy\n");
+
+ pcie_phy->dev = dev;
+ pcie_phy->data = of_device_get_match_data(dev);
+ if (!pcie_phy->data)
+ return dev_err_probe(dev, -EINVAL, "Failed to get phy data\n");
+
+ if (pcie_phy->data->sw_efuse_supported) {
+ /*
+ * Failed to read the efuse data is not a fatal problem,
+ * ignore the failure and keep going.
+ */
+ ret = mtk_pcie_read_efuse(pcie_phy);
+ if (ret == -EPROBE_DEFER || ret == -ENOMEM)
+ return ret;
+ }
+
+ phy_set_drvdata(pcie_phy->phy, pcie_phy);
+
+ provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+ if (IS_ERR(provider))
+ return dev_err_probe(dev, PTR_ERR(provider),
+ "PCIe phy probe failed\n");
+
+ return 0;
+}
+
+static const struct mtk_pcie_phy_data mt8195_data = {
+ .num_lanes = 2,
+ .sw_efuse_supported = true,
+};
+
+static const struct of_device_id mtk_pcie_phy_of_match[] = {
+ { .compatible = "mediatek,mt8195-pcie-phy", .data = &mt8195_data },
+ { },
+};
+MODULE_DEVICE_TABLE(of, mtk_pcie_phy_of_match);
+
+static struct platform_driver mtk_pcie_phy_driver = {
+ .probe = mtk_pcie_phy_probe,
+ .driver = {
+ .name = "mtk-pcie-phy",
+ .of_match_table = mtk_pcie_phy_of_match,
+ },
+};
+module_platform_driver(mtk_pcie_phy_driver);
+
+MODULE_DESCRIPTION("MediaTek PCIe PHY driver");
+MODULE_AUTHOR("Jianjun Wang <jianjun.wang@mediatek.com>");
+MODULE_LICENSE("GPL");
--
2.18.0