[PATCH v2 2/6] phy: qcom: Introduce PCIe UNIPHY 28LP driver

Varadarajan Narayanan
2024-12-04T11:34:30Z

From: Nitheesh Sekar <quic_nsekar@quicinc.com>

Add Qualcomm PCIe UNIPHY 28LP driver support present
in Qualcomm IPQ5332 SoC and the phy init sequence.

Signed-off-by: Nitheesh Sekar <quic_nsekar@quicinc.com>
Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
---
v2: Drop IPQ5018 related code and data
Use uniform prefix for struct names
Place "}, {", on the same line
In qcom_uniphy_pcie_init(), use for-loop instead of while
Swap reset and clock disable order in qcom_uniphy_pcie_power_off
Add reset assert to qcom_uniphy_pcie_power_on's error path
Use macros for usleep duration
Inlined qcom_uniphy_pcie_get_resources & use devm_platform_get_and_ioremap_resource
Drop 'clock-output-names' from phy_pipe_clk_register
---
drivers/phy/qualcomm/Kconfig | 12 +
drivers/phy/qualcomm/Makefile | 1 +
.../phy/qualcomm/phy-qcom-uniphy-pcie-28lp.c | 307 ++++++++++++++++++
3 files changed, 320 insertions(+)
create mode 100644 drivers/phy/qualcomm/phy-qcom-uniphy-pcie-28lp.c

diff --git a/drivers/phy/qualcomm/Kconfig b/drivers/phy/qualcomm/Kconfig
index 846f8c99547f..a6b71fda1b9c 100644
--- a/drivers/phy/qualcomm/Kconfig
+++ b/drivers/phy/qualcomm/Kconfig
@@ -154,6 +154,18 @@ config PHY_QCOM_M31_USB
management. This driver is required even for peripheral only or
host only mode configurations.

+config PHY_QCOM_UNIPHY_PCIE_28LP
+ bool "PCIE UNIPHY 28LP PHY driver"
+ depends on ARCH_QCOM
+ depends on HAS_IOMEM
+ depends on OF
+ select GENERIC_PHY
+ help
+ Enable this to support the PCIe UNIPHY 28LP phy transceiver that
+ is used with PCIe controllers on Qualcomm IPQ5332 chips. It
+ handles PHY initialization, clock management required after
+ resetting the hardware and power management.
+
config PHY_QCOM_USB_HS
tristate "Qualcomm USB HS PHY module"
depends on USB_ULPI_BUS
diff --git a/drivers/phy/qualcomm/Makefile b/drivers/phy/qualcomm/Makefile
index eb60e950ad53..42038bc30974 100644
--- a/drivers/phy/qualcomm/Makefile
+++ b/drivers/phy/qualcomm/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_PHY_QCOM_QMP_USB_LEGACY) += phy-qcom-qmp-usb-legacy.o
obj-$(CONFIG_PHY_QCOM_QUSB2) += phy-qcom-qusb2.o
obj-$(CONFIG_PHY_QCOM_SNPS_EUSB2) += phy-qcom-snps-eusb2.o
obj-$(CONFIG_PHY_QCOM_EUSB2_REPEATER) += phy-qcom-eusb2-repeater.o
+obj-$(CONFIG_PHY_QCOM_UNIPHY_PCIE_28LP) += phy-qcom-uniphy-pcie-28lp.o
obj-$(CONFIG_PHY_QCOM_USB_HS) += phy-qcom-usb-hs.o
obj-$(CONFIG_PHY_QCOM_USB_HSIC) += phy-qcom-usb-hsic.o
obj-$(CONFIG_PHY_QCOM_USB_HS_28NM) += phy-qcom-usb-hs-28nm.o
diff --git a/drivers/phy/qualcomm/phy-qcom-uniphy-pcie-28lp.c b/drivers/phy/qualcomm/phy-qcom-uniphy-pcie-28lp.c
new file mode 100644
index 000000000000..3a8c88040c67
--- /dev/null
+++ b/drivers/phy/qualcomm/phy-qcom-uniphy-pcie-28lp.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2023, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/phy/phy.h>
+#include <linux/reset.h>
+#include <linux/of_device.h>
+#include <linux/delay.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#define RST_ASSERT_DELAY_MIN_US 100
+#define RST_ASSERT_DELAY_MAX_US 150
+#define PIPE_CLK_DELAY_MIN_US 5000
+#define PIPE_CLK_DELAY_MAX_US 5100
+#define CLK_EN_DELAY_MIN_US 30
+#define CLK_EN_DELAY_MAX_US 50
+#define CDR_CTRL_REG_1 0x80
+#define CDR_CTRL_REG_2 0x84
+#define CDR_CTRL_REG_3 0x88
+#define CDR_CTRL_REG_4 0x8C
+#define CDR_CTRL_REG_5 0x90
+#define CDR_CTRL_REG_6 0x94
+#define CDR_CTRL_REG_7 0x98
+#define SSCG_CTRL_REG_1 0x9c
+#define SSCG_CTRL_REG_2 0xa0
+#define SSCG_CTRL_REG_3 0xa4
+#define SSCG_CTRL_REG_4 0xa8
+#define SSCG_CTRL_REG_5 0xac
+#define SSCG_CTRL_REG_6 0xb0
+#define PCS_INTERNAL_CONTROL_2 0x2d8
+
+#define PHY_CFG_PLLCFG 0x220
+#define PHY_CFG_EIOS_DTCT_REG 0x3e4
+#define PHY_CFG_GEN3_ALIGN_HOLDOFF_TIME 0x3e8
+
+#define PHY_MODE_FIXED 0x1
+
+enum qcom_uniphy_pcie_type {
+ PHY_TYPE_PCIE = 1,
+ PHY_TYPE_PCIE_GEN2,
+ PHY_TYPE_PCIE_GEN3,
+};
+
+struct qcom_uniphy_pcie_regs {
+ unsigned int offset;
+ unsigned int val;
+};
+
+struct qcom_uniphy_pcie_data {
+ int lanes;
+ /* 2nd lane offset */
+ int lane_offset;
+ unsigned int phy_type;
+ const struct qcom_uniphy_pcie_regs *init_seq;
+ unsigned int init_seq_num;
+ unsigned int pipe_clk_rate;
+};
+
+struct qcom_uniphy_pcie {
+ struct phy phy;
+ struct device *dev;
+ const struct qcom_uniphy_pcie_data *data;
+ struct clk_bulk_data *clks;
+ int num_clks;
+ struct reset_control *resets;
+ void __iomem *base;
+};
+
+#define phy_to_dw_phy(x) container_of((x), struct qca_uni_pcie_phy, phy)
+
+static const struct qcom_uniphy_pcie_regs ipq5332_regs[] = {
+ {
+ .offset = PHY_CFG_PLLCFG,
+ .val = 0x30,
+ }, {
+ .offset = PHY_CFG_EIOS_DTCT_REG,
+ .val = 0x53ef,
+ }, {
+ .offset = PHY_CFG_GEN3_ALIGN_HOLDOFF_TIME,
+ .val = 0xCf,
+ },
+};
+
+static const struct qcom_uniphy_pcie_data ipq5332_x1_data = {
+ .lanes = 1,
+ .phy_type = PHY_TYPE_PCIE_GEN3,
+ .init_seq = ipq5332_regs,
+ .init_seq_num = ARRAY_SIZE(ipq5332_regs),
+ .pipe_clk_rate = 250000000,
+};
+
+static const struct qcom_uniphy_pcie_data ipq5332_x2_data = {
+ .lanes = 2,
+ .lane_offset = 0x800,
+ .phy_type = PHY_TYPE_PCIE_GEN3,
+ .init_seq = ipq5332_regs,
+ .init_seq_num = ARRAY_SIZE(ipq5332_regs),
+ .pipe_clk_rate = 250000000,
+};
+
+static void qcom_uniphy_pcie_init(struct qcom_uniphy_pcie *phy)
+{
+ const struct qcom_uniphy_pcie_data *data = phy->data;
+ const struct qcom_uniphy_pcie_regs *init_seq;
+ void __iomem *base = phy->base;
+ int lane, i;
+
+ for (lane = 0; lane != data->lanes; lane++) {
+ init_seq = data->init_seq;
+
+ for (i = 0; i < data->init_seq_num; i++, init_seq++)
+ writel(init_seq->val, base + init_seq->offset);
+
+ base += data->lane_offset;
+ }
+}
+
+static int qcom_uniphy_pcie_power_off(struct phy *x)
+{
+ struct qcom_uniphy_pcie *phy = phy_get_drvdata(x);
+
+ clk_bulk_disable_unprepare(phy->num_clks, phy->clks);
+
+ reset_control_assert(phy->resets);
+
+ return 0;
+}
+
+static int qcom_uniphy_pcie_power_on(struct phy *x)
+{
+ struct qcom_uniphy_pcie *phy = phy_get_drvdata(x);
+ int ret;
+
+ ret = reset_control_assert(phy->resets);
+ if (ret) {
+ dev_err(phy->dev, "reset assert failed (%d)\n", ret);
+ return ret;
+ }
+
+ usleep_range(RST_ASSERT_DELAY_MIN_US, RST_ASSERT_DELAY_MAX_US);
+
+ ret = reset_control_deassert(phy->resets);
+ if (ret) {
+ dev_err(phy->dev, "reset deassert failed (%d)\n", ret);
+ return ret;
+ }
+
+ usleep_range(PIPE_CLK_DELAY_MIN_US, PIPE_CLK_DELAY_MAX_US);
+
+ ret = clk_bulk_prepare_enable(phy->num_clks, phy->clks);
+ if (ret) {
+ reset_control_assert(phy->resets);
+ dev_err(phy->dev, "clk prepare and enable failed %d\n", ret);
+ return ret;
+ }
+
+ usleep_range(CLK_EN_DELAY_MIN_US, CLK_EN_DELAY_MAX_US);
+
+ qcom_uniphy_pcie_init(phy);
+ return 0;
+}
+
+static inline int qcom_uniphy_pcie_get_resources(struct platform_device *pdev,
+ struct qcom_uniphy_pcie *phy)
+{
+ struct resource *res;
+
+ phy->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(phy->base))
+ return PTR_ERR(phy->base);
+
+ phy->num_clks = devm_clk_bulk_get_all(phy->dev, &phy->clks);
+ if (phy->num_clks < 0)
+ return phy->num_clks;
+
+ phy->resets = devm_reset_control_array_get_exclusive(phy->dev);
+ if (IS_ERR(phy->resets))
+ return PTR_ERR(phy->resets);
+
+ return 0;
+}
+
+/*
+ * Register a fixed rate pipe clock.
+ *
+ * The _pipe_clksrc generated by PHY goes to the GCC that gate
+ * controls it. The _pipe_clk coming out of the GCC is requested
+ * by the PHY driver for its operations.
+ * We register the _pipe_clksrc here. The gcc driver takes care
+ * of assigning this _pipe_clksrc as parent to _pipe_clk.
+ * Below picture shows this relationship.
+ *
+ * +---------------+
+ * | PHY block |<<---------------------------------------+
+ * | | |
+ * | +-------+ | +-----+ |
+ * I/P---^-->| PLL |---^--->pipe_clksrc--->| GCC |--->pipe_clk---+
+ * clk | +-------+ | +-----+
+ * +---------------+
+ */
+static inline int phy_pipe_clk_register(struct qcom_uniphy_pcie *phy,
+ struct device_node *np)
+{
+ const struct qcom_uniphy_pcie_data *data = phy->data;
+ struct clk_hw *hw;
+ char name[64];
+ int ret;
+
+ snprintf(name, sizeof(name), "%s_pipe_clk_src", np->name);
+ hw = devm_clk_hw_register_fixed_rate(phy->dev, name, NULL, 0,
+ data->pipe_clk_rate);
+ if (IS_ERR(hw))
+ return dev_err_probe(phy->dev, PTR_ERR(hw),
+ "Unable to register %s\n", name);
+
+ ret = devm_of_clk_add_hw_provider(phy->dev, of_clk_hw_simple_get, hw);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static const struct of_device_id qcom_uniphy_pcie_id_table[] = {
+ {
+ .compatible = "qcom,ipq5332-uniphy-pcie-gen3x1",
+ .data = &ipq5332_x1_data,
+ }, {
+ .compatible = "qcom,ipq5332-uniphy-pcie-gen3x2",
+ .data = &ipq5332_x2_data,
+ }, {
+ /* Sentinel */
+ },
+};
+MODULE_DEVICE_TABLE(of, qcom_uniphy_pcie_id_table);
+
+static const struct phy_ops pcie_ops = {
+ .power_on = qcom_uniphy_pcie_power_on,
+ .power_off = qcom_uniphy_pcie_power_off,
+ .owner = THIS_MODULE,
+};
+
+static int qcom_uniphy_pcie_probe(struct platform_device *pdev)
+{
+ struct phy_provider *phy_provider;
+ struct device *dev = &pdev->dev;
+ struct qcom_uniphy_pcie *phy;
+ struct device_node *np;
+ struct phy *generic_phy;
+ int ret;
+
+ np = of_node_get(dev->of_node);
+
+ phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
+ if (!phy)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, phy);
+ phy->dev = &pdev->dev;
+
+ phy->data = of_device_get_match_data(dev);
+ if (!phy->data)
+ return -EINVAL;
+
+ ret = qcom_uniphy_pcie_get_resources(pdev, phy);
+ if (ret < 0)
+ return dev_err_probe(&pdev->dev, ret,
+ "failed to get resources: %d\n", ret);
+
+ ret = phy_pipe_clk_register(phy, np);
+ if (ret)
+ dev_err(&pdev->dev, "failed to register phy pipe clk\n");
+
+ generic_phy = devm_phy_create(phy->dev, NULL, &pcie_ops);
+ if (IS_ERR(generic_phy))
+ return PTR_ERR(generic_phy);
+
+ phy_set_drvdata(generic_phy, phy);
+ phy_provider = devm_of_phy_provider_register(phy->dev,
+ of_phy_simple_xlate);
+ if (IS_ERR(phy_provider))
+ return PTR_ERR(phy_provider);
+
+ return 0;
+}
+
+static struct platform_driver qcom_uniphy_pcie_driver = {
+ .probe = qcom_uniphy_pcie_probe,
+ .driver = {
+ .name = "qcom-uniphy-pcie",
+ .owner = THIS_MODULE,
+ .of_match_table = qcom_uniphy_pcie_id_table,
+ },
+};
+
+module_platform_driver(qcom_uniphy_pcie_driver);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("PCIE QCOM UNIPHY driver");
--
2.34.1