phy: qcom: Add driver for QCOM IPQ806x SATA PHY

Add a PHY driver for uses with AHCI based SATA controller driver on the
IPQ806x family of SoCs.

Signed-off-by: Kumar Gala <[e-mail]>
Signed-off-by: Kishon Vijay Abraham I <[e-mail]>

drivers/phy/Kconfig

···
 	depends on OF
 	select GENERIC_PHY
 
+config PHY_QCOM_IPQ806X_SATA
+	tristate "Qualcomm IPQ806x SATA SerDes/PHY driver"
+	depends on ARCH_QCOM
+	depends on HAS_IOMEM
+	depends on OF
+	select GENERIC_PHY
+
 endmenu

drivers/phy/Makefile

···
 obj-$(CONFIG_PHY_EXYNOS5_USBDRD)	+= phy-exynos5-usbdrd.o
 obj-$(CONFIG_PHY_XGENE)			+= phy-xgene.o
 obj-$(CONFIG_PHY_QCOM_APQ8064_SATA)	+= phy-qcom-apq8064-sata.o
+obj-$(CONFIG_PHY_QCOM_IPQ806X_SATA)	+= phy-qcom-ipq806x-sata.o

drivers/phy/phy-qcom-ipq806x-sata.c

···
+/*
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/time.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/phy/phy.h>
+
+struct qcom_ipq806x_sata_phy {
+	void __iomem *mmio;
+	struct clk *cfg_clk;
+	struct device *dev;
+};
+
+#define __set(v, a, b)	(((v) << (b)) & GENMASK(a, b))
+
+#define SATA_PHY_P0_PARAM0		0x200
+#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3(x)	__set(x, 17, 12)
+#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3_MASK	GENMASK(17, 12)
+#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN2(x)	__set(x, 11, 6)
+#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN2_MASK	GENMASK(11, 6)
+#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN1(x)	__set(x, 5, 0)
+#define SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN1_MASK	GENMASK(5, 0)
+
+#define SATA_PHY_P0_PARAM1		0x204
+#define SATA_PHY_P0_PARAM1_RESERVED_BITS31_21(x)	__set(x, 31, 21)
+#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3(x)	__set(x, 20, 14)
+#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3_MASK	GENMASK(20, 14)
+#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2(x)	__set(x, 13, 7)
+#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2_MASK	GENMASK(13, 7)
+#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1(x)	__set(x, 6, 0)
+#define SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1_MASK	GENMASK(6, 0)
+
+#define SATA_PHY_P0_PARAM2		0x208
+#define SATA_PHY_P0_PARAM2_RX_EQ(x)	__set(x, 20, 18)
+#define SATA_PHY_P0_PARAM2_RX_EQ_MASK	GENMASK(20, 18)
+
+#define SATA_PHY_P0_PARAM3		0x20C
+#define SATA_PHY_SSC_EN			0x8
+#define SATA_PHY_P0_PARAM4		0x210
+#define SATA_PHY_REF_SSP_EN		0x2
+#define SATA_PHY_RESET			0x1
+
+static int qcom_ipq806x_sata_phy_init(struct phy *generic_phy)
+{
+	struct qcom_ipq806x_sata_phy *phy = phy_get_drvdata(generic_phy);
+	u32 reg;
+
+	/* Setting SSC_EN to 1 */
+	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM3);
+	reg = reg | SATA_PHY_SSC_EN;
+	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM3);
+
+	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM0) &
+			~(SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3_MASK |
+			  SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN2_MASK |
+			  SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN1_MASK);
+	reg |= SATA_PHY_P0_PARAM0_P0_TX_PREEMPH_GEN3(0xf);
+	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM0);
+
+	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM1) &
+			~(SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3_MASK |
+			  SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2_MASK |
+			  SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1_MASK);
+	reg |= SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN3(0x55) |
+		SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN2(0x55) |
+		SATA_PHY_P0_PARAM1_P0_TX_AMPLITUDE_GEN1(0x55);
+	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM1);
+
+	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM2) &
+		~SATA_PHY_P0_PARAM2_RX_EQ_MASK;
+	reg |= SATA_PHY_P0_PARAM2_RX_EQ(0x3);
+	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM2);
+
+	/* Setting PHY_RESET to 1 */
+	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
+	reg = reg | SATA_PHY_RESET;
+	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
+
+	/* Setting REF_SSP_EN to 1 */
+	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
+	reg = reg | SATA_PHY_REF_SSP_EN | SATA_PHY_RESET;
+	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
+
+	/* make sure all changes complete before we let the PHY out of reset */
+	mb();
+
+	/* sleep for max. 50us more to combine processor wakeups */
+	usleep_range(20, 20 + 50);
+
+	/* Clearing PHY_RESET to 0 */
+	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
+	reg = reg & ~SATA_PHY_RESET;
+	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
+
+	return 0;
+}
+
+static int qcom_ipq806x_sata_phy_exit(struct phy *generic_phy)
+{
+	struct qcom_ipq806x_sata_phy *phy = phy_get_drvdata(generic_phy);
+	u32 reg;
+
+	/* Setting PHY_RESET to 1 */
+	reg = readl_relaxed(phy->mmio + SATA_PHY_P0_PARAM4);
+	reg = reg | SATA_PHY_RESET;
+	writel_relaxed(reg, phy->mmio + SATA_PHY_P0_PARAM4);
+
+	return 0;
+}
+
+static struct phy_ops qcom_ipq806x_sata_phy_ops = {
+	.init		= qcom_ipq806x_sata_phy_init,
+	.exit		= qcom_ipq806x_sata_phy_exit,
+	.owner		= THIS_MODULE,
+};
+
+static int qcom_ipq806x_sata_phy_probe(struct platform_device *pdev)
+{
+	struct qcom_ipq806x_sata_phy *phy;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct phy_provider *phy_provider;
+	struct phy *generic_phy;
+	int ret;
+
+	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	phy->mmio = devm_ioremap_resource(dev, res);
+	if (IS_ERR(phy->mmio))
+		return PTR_ERR(phy->mmio);
+
+	generic_phy = devm_phy_create(dev, NULL, &qcom_ipq806x_sata_phy_ops,
+				      NULL);
+	if (IS_ERR(generic_phy)) {
+		dev_err(dev, "%s: failed to create phy\n", __func__);
+		return PTR_ERR(generic_phy);
+	}
+
+	phy->dev = dev;
+	phy_set_drvdata(generic_phy, phy);
+	platform_set_drvdata(pdev, phy);
+
+	phy->cfg_clk = devm_clk_get(dev, "cfg");
+	if (IS_ERR(phy->cfg_clk)) {
+		dev_err(dev, "Failed to get sata cfg clock\n");
+		return PTR_ERR(phy->cfg_clk);
+	}
+
+	ret = clk_prepare_enable(phy->cfg_clk);
+	if (ret)
+		return ret;
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+	if (IS_ERR(phy_provider)) {
+		clk_disable_unprepare(phy->cfg_clk);
+		dev_err(dev, "%s: failed to register phy\n", __func__);
+		return PTR_ERR(phy_provider);
+	}
+
+	return 0;
+}
+
+static int qcom_ipq806x_sata_phy_remove(struct platform_device *pdev)
+{
+	struct qcom_ipq806x_sata_phy *phy = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(phy->cfg_clk);
+
+	return 0;
+}
+
+static const struct of_device_id qcom_ipq806x_sata_phy_of_match[] = {
+	{ .compatible = "qcom,ipq806x-sata-phy" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, qcom_ipq806x_sata_phy_of_match);
+
+static struct platform_driver qcom_ipq806x_sata_phy_driver = {
+	.probe	= qcom_ipq806x_sata_phy_probe,
+	.remove	= qcom_ipq806x_sata_phy_remove,
+	.driver = {
+		.name	= "qcom-ipq806x-sata-phy",
+		.owner	= THIS_MODULE,
+		.of_match_table	= qcom_ipq806x_sata_phy_of_match,
+	}
+};
+module_platform_driver(qcom_ipq806x_sata_phy_driver);
+
+MODULE_DESCRIPTION("QCOM IPQ806x SATA PHY driver");
+MODULE_LICENSE("GPL v2");