[PATCH 2/2] phy: socionext: add PCIe PHY driver support

From: Kunihiko Hayashi
Date: Wed Sep 05 2018 - 05:49:57 EST


Add a driver for PHY interface built into PCIe controller implemented
in UniPhier SoCs.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
---
drivers/phy/Kconfig | 1 +
drivers/phy/Makefile | 1 +
drivers/phy/socionext/Kconfig | 12 ++
drivers/phy/socionext/Makefile | 6 +
drivers/phy/socionext/phy-uniphier-pcie.c | 240 ++++++++++++++++++++++++++++++
5 files changed, 260 insertions(+)
create mode 100644 drivers/phy/socionext/Kconfig
create mode 100644 drivers/phy/socionext/Makefile
create mode 100644 drivers/phy/socionext/phy-uniphier-pcie.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 5c8d452..b752589 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -53,6 +53,7 @@ source "drivers/phy/ralink/Kconfig"
source "drivers/phy/renesas/Kconfig"
source "drivers/phy/rockchip/Kconfig"
source "drivers/phy/samsung/Kconfig"
+source "drivers/phy/socionext/Kconfig"
source "drivers/phy/st/Kconfig"
source "drivers/phy/tegra/Kconfig"
source "drivers/phy/ti/Kconfig"
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 84e3bd9..5539cde 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -21,5 +21,6 @@ obj-y += broadcom/ \
qualcomm/ \
ralink/ \
samsung/ \
+ socionext/ \
st/ \
ti/
diff --git a/drivers/phy/socionext/Kconfig b/drivers/phy/socionext/Kconfig
new file mode 100644
index 0000000..20a1195
--- /dev/null
+++ b/drivers/phy/socionext/Kconfig
@@ -0,0 +1,12 @@
+#
+# PHY drivers for Socionext platforms.
+#
+
+config PHY_UNIPHIER_PCIE
+ tristate "Uniphier PHY driver for PCIe controller"
+ depends on (ARCH_UNIPHIER || COMPILE_TEST) && OF
+ default PCIE_UNIPHIER
+ select GENERIC_PHY
+ help
+ Enable this to support PHY implemented in PCIe controller
+ on UniPhier SoCs. This driver supports LD20 and PXs3 SoCs.
diff --git a/drivers/phy/socionext/Makefile b/drivers/phy/socionext/Makefile
new file mode 100644
index 0000000..5484360
--- /dev/null
+++ b/drivers/phy/socionext/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the phy drivers.
+#
+
+obj-$(CONFIG_PHY_UNIPHIER_PCIE) += phy-uniphier-pcie.o
diff --git a/drivers/phy/socionext/phy-uniphier-pcie.c b/drivers/phy/socionext/phy-uniphier-pcie.c
new file mode 100644
index 0000000..93ffbd2
--- /dev/null
+++ b/drivers/phy/socionext/phy-uniphier-pcie.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * phy-uniphier-pcie.c - PHY driver for UniPhier PCIe controller
+ * Copyright 2018, Socionext Inc.
+ * Author: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
+ */
+
+#include <linux/bitops.h>
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/iopoll.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/resource.h>
+
+/* PHY */
+#define PCL_PHY_TEST_I 0x2000
+#define PCL_PHY_TEST_O 0x2004
+#define TESTI_DAT_MASK GENMASK(13, 6)
+#define TESTI_ADR_MASK GENMASK(5, 1)
+#define TESTI_WR_EN BIT(0)
+
+#define PCL_PHY_RESET 0x200c
+#define PCL_PHY_RESET_N_MNMODE BIT(8) /* =1:manual */
+#define PCL_PHY_RESET_N BIT(0) /* =1:deasssert */
+
+/* SG */
+#define SG_USBPCIESEL 0x590
+#define SG_USBPCIESEL_PCIE BIT(0)
+
+#define PCL_PHY_R00 0
+#define RX_EQ_ADJ_EN BIT(3) /* enable for EQ adjustment */
+#define PCL_PHY_R06 6
+#define RX_EQ_ADJ GENMASK(5, 0) /* EQ adjustment value */
+#define RX_EQ_ADJ_VAL 0
+#define PCL_PHY_R26 26
+#define VCO_CTRL GENMASK(7, 4) /* Tx VCO adjustment value */
+#define VCO_CTRL_INIT_VAL 5
+
+struct uniphier_pciephy_priv {
+ void __iomem *base;
+ struct device *dev;
+ struct clk *clk;
+ struct reset_control *rst;
+ const struct uniphier_pciephy_soc_data *data;
+};
+
+struct uniphier_pciephy_soc_data {
+ bool has_syscon;
+};
+
+static void uniphier_pciephy_testio_write(struct uniphier_pciephy_priv *priv,
+ u32 data)
+{
+ /* need to read TESTO twice after accessing TESTI */
+ writel(data, priv->base + PCL_PHY_TEST_I);
+ readl(priv->base + PCL_PHY_TEST_O);
+ readl(priv->base + PCL_PHY_TEST_O);
+}
+
+static void uniphier_pciephy_set_param(struct uniphier_pciephy_priv *priv,
+ u32 reg, u32 mask, u32 param)
+{
+ u32 val;
+
+ /* read previous data */
+ val = FIELD_PREP(TESTI_DAT_MASK, 1);
+ val |= FIELD_PREP(TESTI_ADR_MASK, reg);
+ uniphier_pciephy_testio_write(priv, val);
+ val = readl(priv->base + PCL_PHY_TEST_O);
+
+ /* update value */
+ val &= ~FIELD_PREP(TESTI_DAT_MASK, mask);
+ val = FIELD_PREP(TESTI_DAT_MASK, mask & param);
+ val |= FIELD_PREP(TESTI_ADR_MASK, reg);
+ uniphier_pciephy_testio_write(priv, val);
+ uniphier_pciephy_testio_write(priv, val | TESTI_WR_EN);
+ uniphier_pciephy_testio_write(priv, val);
+
+ /* read current data as dummy */
+ val = FIELD_PREP(TESTI_DAT_MASK, 1);
+ val |= FIELD_PREP(TESTI_ADR_MASK, reg);
+ uniphier_pciephy_testio_write(priv, val);
+ readl(priv->base + PCL_PHY_TEST_O);
+}
+
+static void uniphier_pciephy_assert(struct uniphier_pciephy_priv *priv)
+{
+ u32 val;
+
+ val = readl(priv->base + PCL_PHY_RESET);
+ val &= ~PCL_PHY_RESET_N;
+ val |= PCL_PHY_RESET_N_MNMODE;
+ writel(val, priv->base + PCL_PHY_RESET);
+}
+
+static void uniphier_pciephy_deassert(struct uniphier_pciephy_priv *priv)
+{
+ u32 val;
+
+ val = readl(priv->base + PCL_PHY_RESET);
+ val |= PCL_PHY_RESET_N_MNMODE | PCL_PHY_RESET_N;
+ writel(val, priv->base + PCL_PHY_RESET);
+}
+
+static int uniphier_pciephy_init(struct phy *phy)
+{
+ struct uniphier_pciephy_priv *priv = phy_get_drvdata(phy);
+ int ret;
+
+ ret = clk_prepare_enable(priv->clk);
+ if (ret)
+ return ret;
+
+ ret = reset_control_deassert(priv->rst);
+ if (ret)
+ goto out_clk_disable;
+
+ uniphier_pciephy_set_param(priv, PCL_PHY_R00,
+ RX_EQ_ADJ_EN, RX_EQ_ADJ_EN);
+ uniphier_pciephy_set_param(priv, PCL_PHY_R06, RX_EQ_ADJ,
+ FIELD_PREP(RX_EQ_ADJ, RX_EQ_ADJ_VAL));
+ uniphier_pciephy_set_param(priv, PCL_PHY_R26, VCO_CTRL,
+ FIELD_PREP(VCO_CTRL, VCO_CTRL_INIT_VAL));
+ usleep_range(1, 10);
+
+ uniphier_pciephy_deassert(priv);
+ usleep_range(1, 10);
+
+ return 0;
+
+out_clk_disable:
+ clk_disable_unprepare(priv->clk);
+
+ return ret;
+}
+
+static int uniphier_pciephy_exit(struct phy *phy)
+{
+ struct uniphier_pciephy_priv *priv = phy_get_drvdata(phy);
+
+ uniphier_pciephy_assert(priv);
+ reset_control_assert(priv->rst);
+ clk_disable_unprepare(priv->clk);
+
+ return 0;
+}
+
+static const struct phy_ops uniphier_pciephy_ops = {
+ .init = uniphier_pciephy_init,
+ .exit = uniphier_pciephy_exit,
+ .owner = THIS_MODULE,
+};
+
+static int uniphier_pciephy_probe(struct platform_device *pdev)
+{
+ struct uniphier_pciephy_priv *priv;
+ struct phy_provider *phy_provider;
+ struct device *dev = &pdev->dev;
+ struct regmap *regmap;
+ struct resource *res;
+ struct phy *phy;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->data = of_device_get_match_data(dev);
+ if (WARN_ON(!priv->data))
+ return -EINVAL;
+
+ priv->dev = dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ priv->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ priv->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(priv->clk))
+ return PTR_ERR(priv->clk);
+
+ priv->rst = devm_reset_control_get_shared(dev, NULL);
+ if (IS_ERR(priv->rst))
+ return PTR_ERR(priv->rst);
+
+ phy = devm_phy_create(dev, dev->of_node, &uniphier_pciephy_ops);
+ if (IS_ERR(phy))
+ return PTR_ERR(phy);
+
+ regmap = syscon_regmap_lookup_by_phandle(dev->of_node,
+ "socionext,syscon");
+ if (!IS_ERR(regmap) && priv->data->has_syscon)
+ regmap_update_bits(regmap, SG_USBPCIESEL,
+ SG_USBPCIESEL_PCIE, SG_USBPCIESEL_PCIE);
+
+ phy_set_drvdata(phy, priv);
+ phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+ return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct uniphier_pciephy_soc_data uniphier_ld20_data = {
+ .has_syscon = true,
+};
+
+static const struct uniphier_pciephy_soc_data uniphier_pxs3_data = {
+ .has_syscon = false,
+};
+
+static const struct of_device_id uniphier_pciephy_match[] = {
+ {
+ .compatible = "socionext,uniphier-ld20-pcie-phy",
+ .data = &uniphier_ld20_data,
+ },
+ {
+ .compatible = "socionext,uniphier-pxs3-pcie-phy",
+ .data = &uniphier_pxs3_data,
+ },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, uniphier_pciephy_match);
+
+static struct platform_driver uniphier_pciephy_driver = {
+ .probe = uniphier_pciephy_probe,
+ .driver = {
+ .name = "uniphier-pcie-phy",
+ .of_match_table = uniphier_pciephy_match,
+ },
+};
+module_platform_driver(uniphier_pciephy_driver);
+
+MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("UniPhier PHY driver for PCIe controller");
+MODULE_LICENSE("GPL v2");
--
2.7.4