[PATCH 2/8] phy: qcom: Introduce Super-Speed USB UNIPHY driver

[Praveenkumar I <quic_ipkumar@quicinc.com>]

Adds Qualcomm 22ull Super-Speed USB UNIPHY driver support which
is present in Qualcomm IPQ5332 SoC. This PHY is interfaced with
SNPS DWC3 USB and SNPS DWC PCIe. Either one of the interface
can use the it and selection is done via mux present in TCSR
register. This driver selects the PHY for DWC3 USB and handles
the reset, clocks and regulator.

Signed-off-by: Praveenkumar I <quic_ipkumar@quicinc.com>
---
 drivers/phy/qualcomm/Kconfig               |  11 +
 drivers/phy/qualcomm/Makefile              |   1 +
 drivers/phy/qualcomm/phy-qcom-uniphy-usb.c | 322 +++++++++++++++++++++
 3 files changed, 334 insertions(+)
 create mode 100644 drivers/phy/qualcomm/phy-qcom-uniphy-usb.c

diff --git a/drivers/phy/qualcomm/Kconfig b/drivers/phy/qualcomm/Kconfig
index d891058b7c39..7257c8455c53 100644
--- a/drivers/phy/qualcomm/Kconfig
+++ b/drivers/phy/qualcomm/Kconfig
@@ -154,6 +154,17 @@ config PHY_QCOM_M31_USB
 	  management. This driver is required even for peripheral only or
 	  host only mode configurations.
 
+config PHY_QCOM_UNIPHY_USB
+	tristate "Qualcomm USB Super-Speed UNIPHY driver"
+	depends on USB && (ARCH_QCOM || COMPILE_TEST)
+	select GENERIC_PHY
+	help
+	  Enable this to support the Qualcomm USB Super-Speed UNIPHY transceiver
+	  with DWC3 USB core. It handles PHY initialization, clock
+	  management required after resetting the hardware and power
+	  management. This driver is required even for peripheral only or
+	  host only mode configurations.
+
 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 ffd609ac6233..c3e0112a7a70 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-$(CONFIG_PHY_QCOM_UNIPHY_USB)	+= phy-qcom-uniphy-usb.o
 obj-$(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-usb.c b/drivers/phy/qualcomm/phy-qcom-uniphy-usb.c
new file mode 100644
index 000000000000..fdfc9c225995
--- /dev/null
+++ b/drivers/phy/qualcomm/phy-qcom-uniphy-usb.c
@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+
+#define PCIE_USB_COMBO_PHY_CFG_MISC1		0x214
+#define PCIE_USB_COMBO_PHY_CFG_RX_AFE_2		0x7C4
+#define PCIE_USB_COMBO_PHY_CFG_RX_DLF_DEMUX_2	0x7E8
+
+/* TCSR_USB_MUX_SEL regiter bits */
+#define TCSR_USB_MUX_SEL				BIT(0)
+
+struct phy_init_tbl {
+	unsigned int offset;
+	unsigned int val;
+};
+
+#define PHY_INIT_CFG(o, v)		\
+	{				\
+		.offset = o,		\
+		.val = v,		\
+	}
+
+static const struct phy_init_tbl ipq5332_usb_uniphy_init_tbl[] = {
+	PHY_INIT_CFG(PCIE_USB_COMBO_PHY_CFG_RX_AFE_2, 0x1076),
+	PHY_INIT_CFG(PCIE_USB_COMBO_PHY_CFG_RX_DLF_DEMUX_2, 0x3142),
+	PHY_INIT_CFG(PCIE_USB_COMBO_PHY_CFG_MISC1, 0x3),
+};
+
+struct uniphy_cfg {
+	const struct phy_init_tbl *init_seq;
+	int num_init_seq;
+};
+
+struct uniphy_usb {
+	struct device		*dev;
+	const struct uniphy_cfg	*cfg;
+	struct phy		*phy;
+	void __iomem		*base;
+	struct clk_bulk_data	*clks;
+	unsigned int		num_clks;
+	struct reset_control	*reset;
+	struct regulator	*vreg;
+	struct clk_fixed_rate	pipe_clk_fixed;
+	struct regmap		*tcsr;
+	unsigned int		usb_mux_offset;
+};
+
+static const struct uniphy_cfg ipq5332_usb_uniphy_cfg = {
+	.init_seq	= ipq5332_usb_uniphy_init_tbl,
+	.num_init_seq	= ARRAY_SIZE(ipq5332_usb_uniphy_init_tbl),
+};
+
+static int uniphy_usb_mux_enable(struct uniphy_usb *uniphy, bool enable)
+{
+	struct device *dev = uniphy->dev;
+	unsigned int val;
+	int ret;
+
+	if (!uniphy->tcsr)
+		return -EINVAL;
+
+	ret = regmap_read(uniphy->tcsr, uniphy->usb_mux_offset, &val);
+	if (ret) {
+		dev_err(dev, "Mux read failed: %d\n", ret);
+		return ret;
+	}
+
+	val = enable ? (val | TCSR_USB_MUX_SEL) : (val & ~TCSR_USB_MUX_SEL);
+	ret = regmap_write(uniphy->tcsr, uniphy->usb_mux_offset, val);
+	if (ret) {
+		dev_err(dev, "Mux write failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int uniphy_usb_init(struct phy *phy)
+{
+	struct uniphy_usb *uniphy = phy_get_drvdata(phy);
+	const struct uniphy_cfg *cfg = uniphy->cfg;
+	const struct phy_init_tbl *tbl = cfg->init_seq;
+	void __iomem *base = uniphy->base;
+	struct device *dev = uniphy->dev;
+	int i, ret;
+
+	ret = regulator_enable(uniphy->vreg);
+	if (ret) {
+		dev_err(dev, "failed to enable regulator, %d\n", ret);
+		return ret;
+	}
+
+	/* Perform phy reset */
+	reset_control_assert(uniphy->reset);
+	usleep_range(1, 5);
+	reset_control_deassert(uniphy->reset);
+
+	ret = uniphy_usb_mux_enable(uniphy, true);
+	if (ret < 0)
+		goto err_assert_reset;
+
+	ret = clk_bulk_prepare_enable(uniphy->num_clks, uniphy->clks);
+	if (ret) {
+		dev_err(dev, "failed to enable clocks: %d\n", ret);
+		goto err_assert_reset;
+	}
+
+	/* phy autoload delay */
+	usleep_range(35, 40);
+
+	for (i = 0; i < cfg->num_init_seq; i++)
+		writel(tbl[i].val, base + tbl[i].offset);
+
+	return 0;
+
+err_assert_reset:
+	/* Assert phy reset */
+	reset_control_assert(uniphy->reset);
+
+	return ret;
+}
+
+static int uniphy_usb_shutdown(struct phy *phy)
+{
+	struct uniphy_usb *uniphy = phy_get_drvdata(phy);
+
+	clk_bulk_disable_unprepare(uniphy->num_clks, uniphy->clks);
+
+	uniphy_usb_mux_enable(uniphy, false);
+
+	/* Assert phy reset */
+	reset_control_assert(uniphy->reset);
+
+	regulator_disable(uniphy->vreg);
+
+	return 0;
+}
+
+static const struct phy_ops uniphy_usb_ops = {
+	.power_on	= uniphy_usb_init,
+	.power_off	= uniphy_usb_shutdown,
+	.owner		= THIS_MODULE,
+};
+
+static int qcom_uniphy_usb_mux_init(struct uniphy_usb *uniphy)
+{
+	struct device *dev = uniphy->dev;
+	int ret;
+
+	uniphy->tcsr = syscon_regmap_lookup_by_phandle_args(dev->of_node, "qcom,phy-usb-mux-sel",
+							    1, &uniphy->usb_mux_offset);
+	if (IS_ERR(uniphy->tcsr)) {
+		ret = PTR_ERR(uniphy->tcsr);
+		uniphy->tcsr = NULL;
+		return ret;
+	}
+
+	return 0;
+}
+
+static int qcom_uniphy_usb_clk_init(struct uniphy_usb *uniphy)
+{
+	struct device *dev = uniphy->dev;
+	int ret;
+
+	ret = devm_clk_bulk_get_all(dev, &uniphy->clks);
+	if (ret < 0)
+		return ret;
+
+	uniphy->num_clks = ret;
+
+	return 0;
+}
+
+static void phy_clk_release_provider(void *res)
+{
+	of_clk_del_provider(res);
+}
+
+/*
+ * Register a fixed rate pipe clock.
+ *
+ * The <s>_pipe_clksrc generated by PHY goes to the GCC that gate
+ * controls it. The <s>_pipe_clk coming out of the GCC is requested
+ * by the PHY driver for its operations.
+ * We register the <s>_pipe_clksrc here. The gcc driver takes care
+ * of assigning this <s>_pipe_clksrc as parent to <s>_pipe_clk.
+ * Below picture shows this relationship.
+ *
+ *         +---------------+
+ *         |   PHY block   |<<---------------------------------------+
+ *         |               |                                         |
+ *         |   +-------+   |                   +-----+               |
+ *   I/P---^-->|  PLL  |---^--->pipe_clksrc--->| GCC |--->pipe_clk---+
+ *    clk  |   +-------+   |                   +-----+
+ *         +---------------+
+ */
+static int phy_pipe_clk_register(struct uniphy_usb *uniphy, struct device_node *np)
+{
+	struct clk_fixed_rate *fixed = &uniphy->pipe_clk_fixed;
+	struct device *dev = uniphy->dev;
+	struct clk_init_data init = { };
+	int ret;
+
+	ret = of_property_read_string(np, "clock-output-names", &init.name);
+	if (ret) {
+		dev_err(dev, "%pOFn: No clock-output-names\n", np);
+		return ret;
+	}
+
+	init.ops = &clk_fixed_rate_ops;
+
+	fixed->fixed_rate = 250000000;
+	fixed->hw.init = &init;
+
+	ret = devm_clk_hw_register(dev, &fixed->hw);
+	if (ret)
+		return ret;
+
+	ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &fixed->hw);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, phy_clk_release_provider, np);
+}
+
+static int qcom_uniphy_usb_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct phy_provider *phy_provider;
+	struct uniphy_usb *uniphy;
+	struct device_node *np;
+	int ret;
+
+	uniphy = devm_kzalloc(dev, sizeof(*uniphy), GFP_KERNEL);
+	if (!uniphy)
+		return -ENOMEM;
+
+	uniphy->dev = dev;
+
+	uniphy->cfg = of_device_get_match_data(dev);
+	if (!uniphy->cfg)
+		return -EINVAL;
+
+	uniphy->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(uniphy->base))
+		return PTR_ERR(uniphy->base);
+
+	ret = qcom_uniphy_usb_clk_init(uniphy);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to get clock\n");
+
+	ret = qcom_uniphy_usb_mux_init(uniphy);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to get USB mux\n");
+
+	uniphy->reset = devm_reset_control_get_exclusive_by_index(dev, 0);
+	if (IS_ERR(uniphy->reset))
+		return dev_err_probe(dev, PTR_ERR(uniphy->reset), "failed to get reset\n");
+
+	uniphy->vreg = devm_regulator_get_exclusive(dev, "vdd");
+	if (IS_ERR(uniphy->vreg))
+		return dev_err_probe(dev, PTR_ERR(uniphy->phy), "failed to get vreg\n");
+
+	np = of_node_get(dev->of_node);
+	ret = phy_pipe_clk_register(uniphy, np);
+	if (ret) {
+		dev_err_probe(dev, ret, "failed to register pipe clk\n");
+		goto err;
+	}
+
+	uniphy->phy = devm_phy_create(dev, NULL, &uniphy_usb_ops);
+	if (IS_ERR(uniphy->phy)) {
+		ret = PTR_ERR(uniphy->phy);
+		dev_err_probe(dev, ret, "failed to create PHY\n");
+		goto err;
+	}
+
+	phy_set_drvdata(uniphy->phy, uniphy);
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	ret = PTR_ERR_OR_ZERO(phy_provider);
+
+err:
+	of_node_put(np);
+	return ret;
+}
+
+static const struct of_device_id qcom_uniphy_usb_of_match[] = {
+	{ .compatible = "qcom,ipq5332-usb-uniphy", .data = &ipq5332_usb_uniphy_cfg},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, qcom_uniphy_usb_of_match);
+
+static struct platform_driver qcom_uniphy_usb_driver = {
+	.probe	= qcom_uniphy_usb_probe,
+	.driver = {
+		.of_match_table	= qcom_uniphy_usb_of_match,
+		.name  = "qcom,uniphy-usb",
+	}
+};
+module_platform_driver(qcom_uniphy_usb_driver);
+
+MODULE_DESCRIPTION("Qualcomm Super-Speed USB UNIPHY driver");
+MODULE_LICENSE("GPL");
-- 
2.34.1