PCI: uniphier-ep: Add NX1 support

Add basic support for UniPhier NX1 SoC as non-legacy SoC. This includes
a compatible string, SoC-dependent data containing init() and wait()
functions for the controller.

Link: https://lore.kernel.org/r/1644480596-20037-4-git-send-email-hayashi.kunihiko@socionext.com
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>

Author: khayash1

drivers/pci/controller/dwc/pcie-uniphier-ep.c

@@ -10,6 +10,7 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/init.h>
+#include <linux/iopoll.h>
 #include <linux/of_device.h>
 #include <linux/pci.h>
 #include <linux/phy/phy.h>
@@ -31,6 +32,17 @@
 #define PCL_RSTCTRL2			0x0024
 #define PCL_RSTCTRL_PHY_RESET		BIT(0)
 
+#define PCL_PINCTRL0			0x002c
+#define PCL_PERST_PLDN_REGEN		BIT(12)
+#define PCL_PERST_NOE_REGEN		BIT(11)
+#define PCL_PERST_OUT_REGEN		BIT(8)
+#define PCL_PERST_PLDN_REGVAL		BIT(4)
+#define PCL_PERST_NOE_REGVAL		BIT(3)
+#define PCL_PERST_OUT_REGVAL		BIT(0)
+
+#define PCL_PIPEMON			0x0044
+#define PCL_PCLK_ALIVE			BIT(15)
+
 #define PCL_MODE			0x8000
 #define PCL_MODE_REGEN			BIT(8)
 #define PCL_MODE_REGVAL			BIT(0)
@@ -51,6 +63,9 @@
 #define PCL_APP_INTX			0x8074
 #define PCL_APP_INTX_SYS_INT		BIT(0)
 
+#define PCL_APP_PM0			0x8078
+#define PCL_SYS_AUX_PWR_DET		BIT(8)
+
 /* assertion time of INTx in usec */
 #define PCL_INTX_WIDTH_USEC		30
 
@@ -123,6 +138,55 @@ static void uniphier_pcie_pro5_init_ep(struct uniphier_pcie_ep_priv *priv)
 	msleep(100);
 }
 
+static void uniphier_pcie_nx1_init_ep(struct uniphier_pcie_ep_priv *priv)
+{
+	u32 val;
+
+	/* set EP mode */
+	val = readl(priv->base + PCL_MODE);
+	val |= PCL_MODE_REGEN | PCL_MODE_REGVAL;
+	writel(val, priv->base + PCL_MODE);
+
+	/* use auxiliary power detection */
+	val = readl(priv->base + PCL_APP_PM0);
+	val |= PCL_SYS_AUX_PWR_DET;
+	writel(val, priv->base + PCL_APP_PM0);
+
+	/* assert PERST# */
+	val = readl(priv->base + PCL_PINCTRL0);
+	val &= ~(PCL_PERST_NOE_REGVAL | PCL_PERST_OUT_REGVAL
+		 | PCL_PERST_PLDN_REGVAL);
+	val |= PCL_PERST_NOE_REGEN | PCL_PERST_OUT_REGEN
+		| PCL_PERST_PLDN_REGEN;
+	writel(val, priv->base + PCL_PINCTRL0);
+
+	uniphier_pcie_ltssm_enable(priv, false);
+
+	usleep_range(100000, 200000);
+
+	/* deassert PERST# */
+	val = readl(priv->base + PCL_PINCTRL0);
+	val |= PCL_PERST_OUT_REGVAL | PCL_PERST_OUT_REGEN;
+	writel(val, priv->base + PCL_PINCTRL0);
+}
+
+static int uniphier_pcie_nx1_wait_ep(struct uniphier_pcie_ep_priv *priv)
+{
+	u32 status;
+	int ret;
+
+	/* wait PIPE clock */
+	ret = readl_poll_timeout(priv->base + PCL_PIPEMON, status,
+				 status & PCL_PCLK_ALIVE, 100000, 1000000);
+	if (ret) {
+		dev_err(priv->pci.dev,
+			"Failed to initialize controller in EP mode\n");
+		return ret;
+	}
+
+	return 0;
+}
+
 static int uniphier_pcie_start_link(struct dw_pcie *pci)
 {
 	struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);
@@ -353,11 +417,28 @@ static const struct uniphier_pcie_ep_soc_data uniphier_pro5_data = {
 	},
 };
 
+static const struct uniphier_pcie_ep_soc_data uniphier_nx1_data = {
+	.has_gio = false,
+	.init = uniphier_pcie_nx1_init_ep,
+	.wait = uniphier_pcie_nx1_wait_ep,
+	.features = {
+		.linkup_notifier = false,
+		.msi_capable = true,
+		.msix_capable = false,
+		.align = 1 << 12,
+		.bar_fixed_64bit = BIT(BAR_0) | BIT(BAR_2) | BIT(BAR_4),
+	},
+};
+
 static const struct of_device_id uniphier_pcie_ep_match[] = {
 	{
 		.compatible = "socionext,uniphier-pro5-pcie-ep",
 		.data = &uniphier_pro5_data,
 	},
+	{
+		.compatible = "socionext,uniphier-nx1-pcie-ep",
+		.data = &uniphier_nx1_data,
+	},
 	{ /* sentinel */ },
 };