phy: socionext: Add UniPhier AHCI PHY driver support

Add a driver for PHY interface built into ahci controller implemented
in UniPhier SoCs. This supports PXs2 and PXs3 SoCs.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1598352071-26675-3-git-send-email-hayashi.kunihiko@socionext.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

3 files changed, 332 insertions, 0 deletions

diff --git a/drivers/phy/socionext/Kconfig b/drivers/phy/socionext/Kconfig
index 8c9d7c37536a..a3970e0f89da 100644
--- a/drivers/phy/socionext/Kconfig
+++ b/drivers/phy/socionext/Kconfig
@@ -34,3 +34,13 @@ config PHY_UNIPHIER_PCIE
 	help
 	  Enable this to support PHY implemented in PCIe controller
 	  on UniPhier SoCs. This driver supports LD20 and PXs3 SoCs.
+
+config PHY_UNIPHIER_AHCI
+	tristate "UniPhier AHCI PHY driver"
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	default SATA_AHCI_PLATFORM
+	select GENERIC_PHY
+	help
+	  Enable this to support PHY implemented in AHCI controller
+	  on UniPhier SoCs. This driver supports PXs2 and PXs3 SoCs.
diff --git a/drivers/phy/socionext/Makefile b/drivers/phy/socionext/Makefile
index 7dc9095b5bb7..e67c2da6675c 100644
--- a/drivers/phy/socionext/Makefile
+++ b/drivers/phy/socionext/Makefile
@@ -6,3 +6,4 @@
 obj-$(CONFIG_PHY_UNIPHIER_USB2)	+= phy-uniphier-usb2.o
 obj-$(CONFIG_PHY_UNIPHIER_USB3)	+= phy-uniphier-usb3hs.o phy-uniphier-usb3ss.o
 obj-$(CONFIG_PHY_UNIPHIER_PCIE)	+= phy-uniphier-pcie.o
+obj-$(CONFIG_PHY_UNIPHIER_AHCI)	+= phy-uniphier-ahci.o
diff --git a/drivers/phy/socionext/phy-uniphier-ahci.c b/drivers/phy/socionext/phy-uniphier-ahci.c
new file mode 100644
index 000000000000..7427c40bf4ae
--- /dev/null
+++ b/drivers/phy/socionext/phy-uniphier-ahci.c
@@ -0,0 +1,321 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * phy-uniphier-ahci.c - PHY driver for UniPhier AHCI controller
+ * Copyright 2016-2020, Socionext Inc.
+ * Author: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+struct uniphier_ahciphy_priv {
+	struct device *dev;
+	void __iomem  *base;
+	struct clk *clk, *clk_parent;
+	struct reset_control *rst, *rst_parent;
+	const struct uniphier_ahciphy_soc_data *data;
+};
+
+struct uniphier_ahciphy_soc_data {
+	int (*init)(struct uniphier_ahciphy_priv *priv);
+	int (*power_on)(struct uniphier_ahciphy_priv *priv);
+	int (*power_off)(struct uniphier_ahciphy_priv *priv);
+	bool is_ready_high;
+	bool is_phy_clk;
+};
+
+/* for PXs2/PXs3 */
+#define CKCTRL				0x0
+#define CKCTRL_P0_READY			BIT(15)
+#define CKCTRL_P0_RESET			BIT(10)
+#define CKCTRL_REF_SSP_EN		BIT(9)
+#define TXCTRL0				0x4
+#define TXCTRL0_AMP_G3_MASK		GENMASK(22, 16)
+#define TXCTRL0_AMP_G2_MASK		GENMASK(14, 8)
+#define TXCTRL0_AMP_G1_MASK		GENMASK(6, 0)
+#define TXCTRL1				0x8
+#define TXCTRL1_DEEMPH_G3_MASK		GENMASK(21, 16)
+#define TXCTRL1_DEEMPH_G2_MASK		GENMASK(13, 8)
+#define TXCTRL1_DEEMPH_G1_MASK		GENMASK(5, 0)
+#define RXCTRL				0xc
+#define RXCTRL_LOS_LVL_MASK		GENMASK(20, 16)
+#define RXCTRL_LOS_BIAS_MASK		GENMASK(10, 8)
+#define RXCTRL_RX_EQ_MASK		GENMASK(2, 0)
+
+static void uniphier_ahciphy_pxs2_enable(struct uniphier_ahciphy_priv *priv,
+					 bool enable)
+{
+	u32 val;
+
+	val = readl(priv->base + CKCTRL);
+
+	if (enable) {
+		val |= CKCTRL_REF_SSP_EN;
+		writel(val, priv->base + CKCTRL);
+		val &= ~CKCTRL_P0_RESET;
+		writel(val, priv->base + CKCTRL);
+	} else {
+		val |= CKCTRL_P0_RESET;
+		writel(val, priv->base + CKCTRL);
+		val &= ~CKCTRL_REF_SSP_EN;
+		writel(val, priv->base + CKCTRL);
+	}
+}
+
+static int uniphier_ahciphy_pxs2_power_on(struct uniphier_ahciphy_priv *priv)
+{
+	int ret;
+	u32 val;
+
+	uniphier_ahciphy_pxs2_enable(priv, true);
+
+	/* wait until PLL is ready */
+	if (priv->data->is_ready_high)
+		ret = readl_poll_timeout(priv->base + CKCTRL, val,
+					 (val & CKCTRL_P0_READY), 200, 400);
+	else
+		ret = readl_poll_timeout(priv->base + CKCTRL, val,
+					 !(val & CKCTRL_P0_READY), 200, 400);
+	if (ret) {
+		dev_err(priv->dev, "Failed to check whether PHY PLL is ready\n");
+		uniphier_ahciphy_pxs2_enable(priv, false);
+	}
+
+	return ret;
+}
+
+static int uniphier_ahciphy_pxs2_power_off(struct uniphier_ahciphy_priv *priv)
+{
+	uniphier_ahciphy_pxs2_enable(priv, false);
+
+	return 0;
+}
+
+static int uniphier_ahciphy_pxs3_init(struct uniphier_ahciphy_priv *priv)
+{
+	int i;
+	u32 val;
+
+	/* setup port parameter */
+	val = readl(priv->base + TXCTRL0);
+	val &= ~TXCTRL0_AMP_G3_MASK;
+	val |= FIELD_PREP(TXCTRL0_AMP_G3_MASK, 0x73);
+	val &= ~TXCTRL0_AMP_G2_MASK;
+	val |= FIELD_PREP(TXCTRL0_AMP_G2_MASK, 0x46);
+	val &= ~TXCTRL0_AMP_G1_MASK;
+	val |= FIELD_PREP(TXCTRL0_AMP_G1_MASK, 0x42);
+	writel(val, priv->base + TXCTRL0);
+
+	val = readl(priv->base + TXCTRL1);
+	val &= ~TXCTRL1_DEEMPH_G3_MASK;
+	val |= FIELD_PREP(TXCTRL1_DEEMPH_G3_MASK, 0x23);
+	val &= ~TXCTRL1_DEEMPH_G2_MASK;
+	val |= FIELD_PREP(TXCTRL1_DEEMPH_G2_MASK, 0x05);
+	val &= ~TXCTRL1_DEEMPH_G1_MASK;
+	val |= FIELD_PREP(TXCTRL1_DEEMPH_G1_MASK, 0x05);
+
+	val = readl(priv->base + RXCTRL);
+	val &= ~RXCTRL_LOS_LVL_MASK;
+	val |= FIELD_PREP(RXCTRL_LOS_LVL_MASK, 0x9);
+	val &= ~RXCTRL_LOS_BIAS_MASK;
+	val |= FIELD_PREP(RXCTRL_LOS_BIAS_MASK, 0x2);
+	val &= ~RXCTRL_RX_EQ_MASK;
+	val |= FIELD_PREP(RXCTRL_RX_EQ_MASK, 0x1);
+
+	/* dummy read 25 times to make a wait time for the phy to stabilize */
+	for (i = 0; i < 25; i++)
+		readl(priv->base + CKCTRL);
+
+	return 0;
+}
+
+static int uniphier_ahciphy_init(struct phy *phy)
+{
+	struct uniphier_ahciphy_priv *priv = phy_get_drvdata(phy);
+	int ret;
+
+	ret = clk_prepare_enable(priv->clk_parent);
+	if (ret)
+		return ret;
+
+	ret = reset_control_deassert(priv->rst_parent);
+	if (ret)
+		goto out_clk_disable;
+
+	if (priv->data->init) {
+		ret = priv->data->init(priv);
+		if (ret)
+			goto out_rst_assert;
+	}
+
+	return 0;
+
+out_rst_assert:
+	reset_control_assert(priv->rst_parent);
+out_clk_disable:
+	clk_disable_unprepare(priv->clk_parent);
+
+	return ret;
+}
+
+static int uniphier_ahciphy_exit(struct phy *phy)
+{
+	struct uniphier_ahciphy_priv *priv = phy_get_drvdata(phy);
+
+	reset_control_assert(priv->rst_parent);
+	clk_disable_unprepare(priv->clk_parent);
+
+	return 0;
+}
+
+static int uniphier_ahciphy_power_on(struct phy *phy)
+{
+	struct uniphier_ahciphy_priv *priv = phy_get_drvdata(phy);
+	int ret = 0;
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	ret = reset_control_deassert(priv->rst);
+	if (ret)
+		goto out_clk_disable;
+
+	if (priv->data->power_on) {
+		ret = priv->data->power_on(priv);
+		if (ret)
+			goto out_reset_assert;
+	}
+
+	return 0;
+
+out_reset_assert:
+	reset_control_assert(priv->rst);
+out_clk_disable:
+	clk_disable_unprepare(priv->clk);
+
+	return ret;
+}
+
+static int uniphier_ahciphy_power_off(struct phy *phy)
+{
+	struct uniphier_ahciphy_priv *priv = phy_get_drvdata(phy);
+	int ret = 0;
+
+	if (priv->data->power_off)
+		ret = priv->data->power_off(priv);
+
+	reset_control_assert(priv->rst);
+	clk_disable_unprepare(priv->clk);
+
+	return ret;
+}
+
+static const struct phy_ops uniphier_ahciphy_ops = {
+	.init  = uniphier_ahciphy_init,
+	.exit  = uniphier_ahciphy_exit,
+	.power_on  = uniphier_ahciphy_power_on,
+	.power_off = uniphier_ahciphy_power_off,
+	.owner = THIS_MODULE,
+};
+
+static int uniphier_ahciphy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct uniphier_ahciphy_priv *priv;
+	struct phy *phy;
+	struct phy_provider *phy_provider;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	priv->data = of_device_get_match_data(dev);
+	if (WARN_ON(!priv->data))
+		return -EINVAL;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	priv->clk_parent = devm_clk_get(dev, "link");
+	if (IS_ERR(priv->clk_parent))
+		return PTR_ERR(priv->clk_parent);
+
+	if (priv->data->is_phy_clk) {
+		priv->clk = devm_clk_get(dev, "phy");
+		if (IS_ERR(priv->clk))
+			return PTR_ERR(priv->clk);
+	}
+
+	priv->rst_parent = devm_reset_control_get_shared(dev, "link");
+	if (IS_ERR(priv->rst_parent))
+		return PTR_ERR(priv->rst_parent);
+
+	priv->rst = devm_reset_control_get_shared(dev, "phy");
+	if (IS_ERR(priv->rst))
+		return PTR_ERR(priv->rst);
+
+	phy = devm_phy_create(dev, dev->of_node, &uniphier_ahciphy_ops);
+	if (IS_ERR(phy)) {
+		dev_err(dev, "failed to create phy\n");
+		return PTR_ERR(phy);
+	}
+
+	phy_set_drvdata(phy, priv);
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+	if (IS_ERR(phy_provider))
+		return PTR_ERR(phy_provider);
+
+	return 0;
+}
+
+static const struct uniphier_ahciphy_soc_data uniphier_pxs2_data = {
+	.power_on  = uniphier_ahciphy_pxs2_power_on,
+	.power_off = uniphier_ahciphy_pxs2_power_off,
+	.is_ready_high = false,
+	.is_phy_clk = false,
+};
+
+static const struct uniphier_ahciphy_soc_data uniphier_pxs3_data = {
+	.init      = uniphier_ahciphy_pxs3_init,
+	.power_on  = uniphier_ahciphy_pxs2_power_on,
+	.power_off = uniphier_ahciphy_pxs2_power_off,
+	.is_ready_high = true,
+	.is_phy_clk = true,
+};
+
+static const struct of_device_id uniphier_ahciphy_match[] = {
+	{
+		.compatible = "socionext,uniphier-pxs2-ahci-phy",
+		.data = &uniphier_pxs2_data,
+	},
+	{
+		.compatible = "socionext,uniphier-pxs3-ahci-phy",
+		.data = &uniphier_pxs3_data,
+	},
+	{ /* Sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, uniphier_ahciphy_match);
+
+static struct platform_driver uniphier_ahciphy_driver = {
+	.probe = uniphier_ahciphy_probe,
+	.driver = {
+		.name = "uniphier-ahci-phy",
+		.of_match_table = uniphier_ahciphy_match,
+	},
+};
+module_platform_driver(uniphier_ahciphy_driver);
+
+MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
+MODULE_DESCRIPTION("UniPhier PHY driver for AHCI controller");
+MODULE_LICENSE("GPL v2");