phy: qualcomm: Add Synopsys 28nm Hi-Speed USB PHY driver

Adds Qualcomm 28nm Hi-Speed USB PHY driver support. This PHY is usually
paired with Synopsys DWC3 USB controllers on Qualcomm SoCs.

The PHY can come in two flavours femtoPHY or picoPHY. This commit adds
support for the femtoPHY with the possibility of extending to the picoPHY
with additional future commits. Both PHYs are on a 28 nanometer process
node.

[bod: Updated qcom_snps_hsphy_set_mode to match new method signature
      Added disjunct on mode > 0
      Removed regulator_set_voltage() in favour of setting floor in dts
      Removed 'snps' and from driver name
      Extended commit log to mention femtoPHY and picoPHY for future
      reference.]
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Jorge Ramirez-Ortiz <jorge.ramirez.ortiz@gmail.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Tested-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NBryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>

drivers/phy/qualcomm/Kconfig

@@ -91,3 +91,14 @@ config PHY_QCOM_USB_HSIC
 	select GENERIC_PHY
 	help
 	  Support for the USB HSIC ULPI compliant PHY on QCOM chipsets.
+
+config PHY_QCOM_USB_HS_28NM
+	tristate "Qualcomm 28nm High-Speed PHY"
+	depends on ARCH_QCOM || COMPILE_TEST
+	depends on EXTCON || !EXTCON # if EXTCON=m, this cannot be built-in
+	select GENERIC_PHY
+	help
+	  Enable this to support the Qualcomm Synopsys DesignWare Core 28nm
+	  High-Speed PHY driver. This driver supports the Hi-Speed PHY which
+	  is usually paired with either the ChipIdea or Synopsys DWC3 USB
+	  IPs on MSM SOCs.

drivers/phy/qualcomm/Makefile

@@ -10,3 +10,4 @@ obj-$(CONFIG_PHY_QCOM_UFS_14NM)		+= phy-qcom-ufs-qmp-14nm.o
 obj-$(CONFIG_PHY_QCOM_UFS_20NM)		+= phy-qcom-ufs-qmp-20nm.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

drivers/phy/qualcomm/phy-qcom-usb-hs-28nm.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2009-2018, Linux Foundation. All rights reserved.
+ * Copyright (c) 2018-2020, Linaro Limited
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+
+/* PHY register and bit definitions */
+#define PHY_CTRL_COMMON0		0x078
+#define SIDDQ				BIT(2)
+#define PHY_IRQ_CMD			0x0d0
+#define PHY_INTR_MASK0			0x0d4
+#define PHY_INTR_CLEAR0			0x0dc
+#define DPDM_MASK			0x1e
+#define DP_1_0				BIT(4)
+#define DP_0_1				BIT(3)
+#define DM_1_0				BIT(2)
+#define DM_0_1				BIT(1)
+
+enum hsphy_voltage {
+	VOL_NONE,
+	VOL_MIN,
+	VOL_MAX,
+	VOL_NUM,
+};
+
+enum hsphy_vreg {
+	VDD,
+	VDDA_1P8,
+	VDDA_3P3,
+	VREG_NUM,
+};
+
+struct hsphy_init_seq {
+	int offset;
+	int val;
+	int delay;
+};
+
+struct hsphy_data {
+	const struct hsphy_init_seq *init_seq;
+	unsigned int init_seq_num;
+};
+
+struct hsphy_priv {
+	void __iomem *base;
+	struct clk_bulk_data *clks;
+	int num_clks;
+	struct reset_control *phy_reset;
+	struct reset_control *por_reset;
+	struct regulator_bulk_data vregs[VREG_NUM];
+	const struct hsphy_data *data;
+	enum phy_mode mode;
+};
+
+static int qcom_snps_hsphy_set_mode(struct phy *phy, enum phy_mode mode,
+				    int submode)
+{
+	struct hsphy_priv *priv = phy_get_drvdata(phy);
+
+	priv->mode = PHY_MODE_INVALID;
+
+	if (mode > 0)
+		priv->mode = mode;
+
+	return 0;
+}
+
+static void qcom_snps_hsphy_enable_hv_interrupts(struct hsphy_priv *priv)
+{
+	u32 val;
+
+	/* Clear any existing interrupts before enabling the interrupts */
+	val = readb(priv->base + PHY_INTR_CLEAR0);
+	val |= DPDM_MASK;
+	writeb(val, priv->base + PHY_INTR_CLEAR0);
+
+	writeb(0x0, priv->base + PHY_IRQ_CMD);
+	usleep_range(200, 220);
+	writeb(0x1, priv->base + PHY_IRQ_CMD);
+
+	/* Make sure the interrupts are cleared */
+	usleep_range(200, 220);
+
+	val = readb(priv->base + PHY_INTR_MASK0);
+	switch (priv->mode) {
+	case PHY_MODE_USB_HOST_HS:
+	case PHY_MODE_USB_HOST_FS:
+	case PHY_MODE_USB_DEVICE_HS:
+	case PHY_MODE_USB_DEVICE_FS:
+		val |= DP_1_0 | DM_0_1;
+		break;
+	case PHY_MODE_USB_HOST_LS:
+	case PHY_MODE_USB_DEVICE_LS:
+		val |= DP_0_1 | DM_1_0;
+		break;
+	default:
+		/* No device connected */
+		val |= DP_0_1 | DM_0_1;
+		break;
+	}
+	writeb(val, priv->base + PHY_INTR_MASK0);
+}
+
+static void qcom_snps_hsphy_disable_hv_interrupts(struct hsphy_priv *priv)
+{
+	u32 val;
+
+	val = readb(priv->base + PHY_INTR_MASK0);
+	val &= ~DPDM_MASK;
+	writeb(val, priv->base + PHY_INTR_MASK0);
+
+	/* Clear any pending interrupts */
+	val = readb(priv->base + PHY_INTR_CLEAR0);
+	val |= DPDM_MASK;
+	writeb(val, priv->base + PHY_INTR_CLEAR0);
+
+	writeb(0x0, priv->base + PHY_IRQ_CMD);
+	usleep_range(200, 220);
+
+	writeb(0x1, priv->base + PHY_IRQ_CMD);
+	usleep_range(200, 220);
+}
+
+static void qcom_snps_hsphy_enter_retention(struct hsphy_priv *priv)
+{
+	u32 val;
+
+	val = readb(priv->base + PHY_CTRL_COMMON0);
+	val |= SIDDQ;
+	writeb(val, priv->base + PHY_CTRL_COMMON0);
+}
+
+static void qcom_snps_hsphy_exit_retention(struct hsphy_priv *priv)
+{
+	u32 val;
+
+	val = readb(priv->base + PHY_CTRL_COMMON0);
+	val &= ~SIDDQ;
+	writeb(val, priv->base + PHY_CTRL_COMMON0);
+}
+
+static int qcom_snps_hsphy_power_on(struct phy *phy)
+{
+	struct hsphy_priv *priv = phy_get_drvdata(phy);
+	int ret;
+
+	ret = regulator_bulk_enable(VREG_NUM, priv->vregs);
+	if (ret)
+		return ret;
+	ret = clk_bulk_prepare_enable(priv->num_clks, priv->clks);
+	if (ret)
+		goto err_disable_regulator;
+	qcom_snps_hsphy_disable_hv_interrupts(priv);
+	qcom_snps_hsphy_exit_retention(priv);
+
+	return 0;
+
+err_disable_regulator:
+	regulator_bulk_disable(VREG_NUM, priv->vregs);
+
+	return ret;
+}
+
+static int qcom_snps_hsphy_power_off(struct phy *phy)
+{
+	struct hsphy_priv *priv = phy_get_drvdata(phy);
+
+	qcom_snps_hsphy_enter_retention(priv);
+	qcom_snps_hsphy_enable_hv_interrupts(priv);
+	clk_bulk_disable_unprepare(priv->num_clks, priv->clks);
+	regulator_bulk_disable(VREG_NUM, priv->vregs);
+
+	return 0;
+}
+
+static int qcom_snps_hsphy_reset(struct hsphy_priv *priv)
+{
+	int ret;
+
+	ret = reset_control_assert(priv->phy_reset);
+	if (ret)
+		return ret;
+
+	usleep_range(10, 15);
+
+	ret = reset_control_deassert(priv->phy_reset);
+	if (ret)
+		return ret;
+
+	usleep_range(80, 100);
+
+	return 0;
+}
+
+static void qcom_snps_hsphy_init_sequence(struct hsphy_priv *priv)
+{
+	const struct hsphy_data *data = priv->data;
+	const struct hsphy_init_seq *seq;
+	int i;
+
+	/* Device match data is optional. */
+	if (!data)
+		return;
+
+	seq = data->init_seq;
+
+	for (i = 0; i < data->init_seq_num; i++, seq++) {
+		writeb(seq->val, priv->base + seq->offset);
+		if (seq->delay)
+			usleep_range(seq->delay, seq->delay + 10);
+	}
+}
+
+static int qcom_snps_hsphy_por_reset(struct hsphy_priv *priv)
+{
+	int ret;
+
+	ret = reset_control_assert(priv->por_reset);
+	if (ret)
+		return ret;
+
+	/*
+	 * The Femto PHY is POR reset in the following scenarios.
+	 *
+	 * 1. After overriding the parameter registers.
+	 * 2. Low power mode exit from PHY retention.
+	 *
+	 * Ensure that SIDDQ is cleared before bringing the PHY
+	 * out of reset.
+	 */
+	qcom_snps_hsphy_exit_retention(priv);
+
+	/*
+	 * As per databook, 10 usec delay is required between
+	 * PHY POR assert and de-assert.
+	 */
+	usleep_range(10, 20);
+	ret = reset_control_deassert(priv->por_reset);
+	if (ret)
+		return ret;
+
+	/*
+	 * As per databook, it takes 75 usec for PHY to stabilize
+	 * after the reset.
+	 */
+	usleep_range(80, 100);
+
+	return 0;
+}
+
+static int qcom_snps_hsphy_init(struct phy *phy)
+{
+	struct hsphy_priv *priv = phy_get_drvdata(phy);
+	int ret;
+
+	ret = qcom_snps_hsphy_reset(priv);
+	if (ret)
+		return ret;
+
+	qcom_snps_hsphy_init_sequence(priv);
+
+	ret = qcom_snps_hsphy_por_reset(priv);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct phy_ops qcom_snps_hsphy_ops = {
+	.init = qcom_snps_hsphy_init,
+	.power_on = qcom_snps_hsphy_power_on,
+	.power_off = qcom_snps_hsphy_power_off,
+	.set_mode = qcom_snps_hsphy_set_mode,
+	.owner = THIS_MODULE,
+};
+
+static const char * const qcom_snps_hsphy_clks[] = {
+	"ref",
+	"ahb",
+	"sleep",
+};
+
+static int qcom_snps_hsphy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct phy_provider *provider;
+	struct hsphy_priv *priv;
+	struct phy *phy;
+	int ret;
+	int i;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	priv->num_clks = ARRAY_SIZE(qcom_snps_hsphy_clks);
+	priv->clks = devm_kcalloc(dev, priv->num_clks, sizeof(*priv->clks),
+				  GFP_KERNEL);
+	if (!priv->clks)
+		return -ENOMEM;
+
+	for (i = 0; i < priv->num_clks; i++)
+		priv->clks[i].id = qcom_snps_hsphy_clks[i];
+
+	ret = devm_clk_bulk_get(dev, priv->num_clks, priv->clks);
+	if (ret)
+		return ret;
+
+	priv->phy_reset = devm_reset_control_get_exclusive(dev, "phy");
+	if (IS_ERR(priv->phy_reset))
+		return PTR_ERR(priv->phy_reset);
+
+	priv->por_reset = devm_reset_control_get_exclusive(dev, "por");
+	if (IS_ERR(priv->por_reset))
+		return PTR_ERR(priv->por_reset);
+
+	priv->vregs[VDD].supply = "vdd";
+	priv->vregs[VDDA_1P8].supply = "vdda1p8";
+	priv->vregs[VDDA_3P3].supply = "vdda3p3";
+
+	ret = devm_regulator_bulk_get(dev, VREG_NUM, priv->vregs);
+	if (ret)
+		return ret;
+
+	/* Get device match data */
+	priv->data = device_get_match_data(dev);
+
+	phy = devm_phy_create(dev, dev->of_node, &qcom_snps_hsphy_ops);
+	if (IS_ERR(phy))
+		return PTR_ERR(phy);
+
+	phy_set_drvdata(phy, priv);
+
+	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+	if (IS_ERR(provider))
+		return PTR_ERR(provider);
+
+	ret = regulator_set_load(priv->vregs[VDDA_1P8].consumer, 19000);
+	if (ret < 0)
+		return ret;
+
+	ret = regulator_set_load(priv->vregs[VDDA_3P3].consumer, 16000);
+	if (ret < 0)
+		goto unset_1p8_load;
+
+	return 0;
+
+unset_1p8_load:
+	regulator_set_load(priv->vregs[VDDA_1P8].consumer, 0);
+
+	return ret;
+}
+
+/*
+ * The macro is used to define an initialization sequence.  Each tuple
+ * is meant to program 'value' into phy register at 'offset' with 'delay'
+ * in us followed.
+ */
+#define HSPHY_INIT_CFG(o, v, d)	{ .offset = o, .val = v, .delay = d, }
+
+static const struct hsphy_init_seq init_seq_femtophy[] = {
+	HSPHY_INIT_CFG(0xc0, 0x01, 0),
+	HSPHY_INIT_CFG(0xe8, 0x0d, 0),
+	HSPHY_INIT_CFG(0x74, 0x12, 0),
+	HSPHY_INIT_CFG(0x98, 0x63, 0),
+	HSPHY_INIT_CFG(0x9c, 0x03, 0),
+	HSPHY_INIT_CFG(0xa0, 0x1d, 0),
+	HSPHY_INIT_CFG(0xa4, 0x03, 0),
+	HSPHY_INIT_CFG(0x8c, 0x23, 0),
+	HSPHY_INIT_CFG(0x78, 0x08, 0),
+	HSPHY_INIT_CFG(0x7c, 0xdc, 0),
+	HSPHY_INIT_CFG(0x90, 0xe0, 20),
+	HSPHY_INIT_CFG(0x74, 0x10, 0),
+	HSPHY_INIT_CFG(0x90, 0x60, 0),
+};
+
+static const struct hsphy_data hsphy_data_femtophy = {
+	.init_seq = init_seq_femtophy,
+	.init_seq_num = ARRAY_SIZE(init_seq_femtophy),
+};
+
+static const struct of_device_id qcom_snps_hsphy_match[] = {
+	{ .compatible = "qcom,usb-hs-28nm-femtophy", .data = &hsphy_data_femtophy, },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, qcom_snps_hsphy_match);
+
+static struct platform_driver qcom_snps_hsphy_driver = {
+	.probe = qcom_snps_hsphy_probe,
+	.driver	= {
+		.name = "qcom,usb-hs-28nm-phy",
+		.of_match_table = qcom_snps_hsphy_match,
+	},
+};
+module_platform_driver(qcom_snps_hsphy_driver);
+
+MODULE_DESCRIPTION("Qualcomm 28nm Hi-Speed USB PHY driver");
+MODULE_LICENSE("GPL v2");