Merge branch 'pci/controller/rcar-gen4'

- Add Synopsys DWC macros for lane skew configuration (Yoshihiro Shimoda)

- Add struct rcar_gen4_pcie_drvdata to provide for future SoCs with
  different initialization requirements (Yoshihiro Shimoda)

- Add .ltssm_control() method for SoC dependencies (Yoshihiro Shimoda)

- Add r8a779g0 (R-Car V4H) support (Yoshihiro Shimoda)

* pci/controller/rcar-gen4:
  PCI: rcar-gen4: Add support for R-Car V4H
  PCI: rcar-gen4: Add .ltssm_control() for other SoC support
  PCI: rcar-gen4: Add struct rcar_gen4_pcie_drvdata
  PCI: dwc: Add PCIE_PORT_{FORCE,LANE_SKEW} macros

2 files changed, 276 insertions, 34 deletions

diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index f49f493b0344..53c4c8f399c8 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -69,6 +69,9 @@
 #define LINK_WAIT_IATU			9
 
 /* Synopsys-specific PCIe configuration registers */
+#define PCIE_PORT_FORCE			0x708
+#define PORT_FORCE_DO_DESKEW_FOR_SRIS	BIT(23)
+
 #define PCIE_PORT_AFR			0x70C
 #define PORT_AFR_N_FTS_MASK		GENMASK(15, 8)
 #define PORT_AFR_N_FTS(n)		FIELD_PREP(PORT_AFR_N_FTS_MASK, n)
@@ -90,6 +93,9 @@
 #define PORT_LINK_MODE_4_LANES		PORT_LINK_MODE(0x7)
 #define PORT_LINK_MODE_8_LANES		PORT_LINK_MODE(0xf)
 
+#define PCIE_PORT_LANE_SKEW		0x714
+#define PORT_LANE_SKEW_INSERT_MASK	GENMASK(23, 0)
+
 #define PCIE_PORT_DEBUG0		0x728
 #define PORT_LOGIC_LTSSM_STATE_MASK	0x1f
 #define PORT_LOGIC_LTSSM_STATE_L0	0x11
diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index 74ccc927a9cb..f0f3ebd1a033 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -2,11 +2,17 @@
 /*
  * PCIe controller driver for Renesas R-Car Gen4 Series SoCs
  * Copyright (C) 2022-2023 Renesas Electronics Corporation
+ *
+ * The r8a779g0 (R-Car V4H) controller requires a specific firmware to be
+ * provided, to initialize the PHY. Otherwise, the PCIe controller will not
+ * work.
  */
 
 #include <linux/delay.h>
+#include <linux/firmware.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/pci.h>
@@ -20,9 +26,10 @@
 /* Renesas-specific */
 /* PCIe Mode Setting Register 0 */
 #define PCIEMSR0		0x0000
-#define BIFUR_MOD_SET_ON	BIT(0)
+#define APP_SRIS_MODE		BIT(6)
 #define DEVICE_TYPE_EP		0
 #define DEVICE_TYPE_RC		BIT(4)
+#define BIFUR_MOD_SET_ON	BIT(0)
 
 /* PCIe Interrupt Status 0 */
 #define PCIEINTSTS0		0x0084
@@ -37,47 +44,49 @@
 #define PCIEDMAINTSTSEN		0x0314
 #define PCIEDMAINTSTSEN_INIT	GENMASK(15, 0)
 
+/* Port Logic Registers 89 */
+#define PRTLGC89		0x0b70
+
+/* Port Logic Registers 90 */
+#define PRTLGC90		0x0b74
+
 /* PCIe Reset Control Register 1 */
 #define PCIERSTCTRL1		0x0014
 #define APP_HOLD_PHY_RST	BIT(16)
 #define APP_LTSSM_ENABLE	BIT(0)
 
+/* PCIe Power Management Control */
+#define PCIEPWRMNGCTRL		0x0070
+#define APP_CLK_REQ_N		BIT(11)
+#define APP_CLK_PM_EN		BIT(10)
+
 #define RCAR_NUM_SPEED_CHANGE_RETRIES	10
 #define RCAR_MAX_LINK_SPEED		4
 
 #define RCAR_GEN4_PCIE_EP_FUNC_DBI_OFFSET	0x1000
 #define RCAR_GEN4_PCIE_EP_FUNC_DBI2_OFFSET	0x800
 
+#define RCAR_GEN4_PCIE_FIRMWARE_NAME		"rcar_gen4_pcie.bin"
+#define RCAR_GEN4_PCIE_FIRMWARE_BASE_ADDR	0xc000
+MODULE_FIRMWARE(RCAR_GEN4_PCIE_FIRMWARE_NAME);
+
+struct rcar_gen4_pcie;
+struct rcar_gen4_pcie_drvdata {
+	void (*additional_common_init)(struct rcar_gen4_pcie *rcar);
+	int (*ltssm_control)(struct rcar_gen4_pcie *rcar, bool enable);
+	enum dw_pcie_device_mode mode;
+};
+
 struct rcar_gen4_pcie {
 	struct dw_pcie dw;
 	void __iomem *base;
+	void __iomem *phy_base;
 	struct platform_device *pdev;
-	enum dw_pcie_device_mode mode;
+	const struct rcar_gen4_pcie_drvdata *drvdata;
 };
 #define to_rcar_gen4_pcie(_dw)	container_of(_dw, struct rcar_gen4_pcie, dw)
 
 /* Common */
-static void rcar_gen4_pcie_ltssm_enable(struct rcar_gen4_pcie *rcar,
-					bool enable)
-{
-	u32 val;
-
-	val = readl(rcar->base + PCIERSTCTRL1);
-	if (enable) {
-		val |= APP_LTSSM_ENABLE;
-		val &= ~APP_HOLD_PHY_RST;
-	} else {
-		/*
-		 * Since the datasheet of R-Car doesn't mention how to assert
-		 * the APP_HOLD_PHY_RST, don't assert it again. Otherwise,
-		 * hang-up issue happened in the dw_edma_core_off() when
-		 * the controller didn't detect a PCI device.
-		 */
-		val &= ~APP_LTSSM_ENABLE;
-	}
-	writel(val, rcar->base + PCIERSTCTRL1);
-}
-
 static int rcar_gen4_pcie_link_up(struct dw_pcie *dw)
 {
 	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
@@ -123,9 +132,13 @@ static int rcar_gen4_pcie_speed_change(struct dw_pcie *dw)
 static int rcar_gen4_pcie_start_link(struct dw_pcie *dw)
 {
 	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
-	int i, changes;
+	int i, changes, ret;
 
-	rcar_gen4_pcie_ltssm_enable(rcar, true);
+	if (rcar->drvdata->ltssm_control) {
+		ret = rcar->drvdata->ltssm_control(rcar, true);
+		if (ret)
+			return ret;
+	}
 
 	/*
 	 * Require direct speed change with retrying here if the link_gen is
@@ -137,7 +150,7 @@ static int rcar_gen4_pcie_start_link(struct dw_pcie *dw)
 	 * Since dw_pcie_setup_rc() sets it once, PCIe Gen2 will be trained.
 	 * So, this needs remaining times for up to PCIe Gen4 if RC mode.
 	 */
-	if (changes && rcar->mode == DW_PCIE_RC_TYPE)
+	if (changes && rcar->drvdata->mode == DW_PCIE_RC_TYPE)
 		changes--;
 
 	for (i = 0; i < changes; i++) {
@@ -153,7 +166,8 @@ static void rcar_gen4_pcie_stop_link(struct dw_pcie *dw)
 {
 	struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
 
-	rcar_gen4_pcie_ltssm_enable(rcar, false);
+	if (rcar->drvdata->ltssm_control)
+		rcar->drvdata->ltssm_control(rcar, false);
 }
 
 static int rcar_gen4_pcie_common_init(struct rcar_gen4_pcie *rcar)
@@ -172,9 +186,9 @@ static int rcar_gen4_pcie_common_init(struct rcar_gen4_pcie *rcar)
 		reset_control_assert(dw->core_rsts[DW_PCIE_PWR_RST].rstc);
 
 	val = readl(rcar->base + PCIEMSR0);
-	if (rcar->mode == DW_PCIE_RC_TYPE) {
+	if (rcar->drvdata->mode == DW_PCIE_RC_TYPE) {
 		val |= DEVICE_TYPE_RC;
-	} else if (rcar->mode == DW_PCIE_EP_TYPE) {
+	} else if (rcar->drvdata->mode == DW_PCIE_EP_TYPE) {
 		val |= DEVICE_TYPE_EP;
 	} else {
 		ret = -EINVAL;
@@ -190,6 +204,9 @@ static int rcar_gen4_pcie_common_init(struct rcar_gen4_pcie *rcar)
 	if (ret)
 		goto err_unprepare;
 
+	if (rcar->drvdata->additional_common_init)
+		rcar->drvdata->additional_common_init(rcar);
+
 	return 0;
 
 err_unprepare:
@@ -231,6 +248,10 @@ static void rcar_gen4_pcie_unprepare(struct rcar_gen4_pcie *rcar)
 
 static int rcar_gen4_pcie_get_resources(struct rcar_gen4_pcie *rcar)
 {
+	rcar->phy_base = devm_platform_ioremap_resource_byname(rcar->pdev, "phy");
+	if (IS_ERR(rcar->phy_base))
+		return PTR_ERR(rcar->phy_base);
+
 	/* Renesas-specific registers */
 	rcar->base = devm_platform_ioremap_resource_byname(rcar->pdev, "app");
 
@@ -451,9 +472,11 @@ static void rcar_gen4_remove_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
 /* Common */
 static int rcar_gen4_add_dw_pcie(struct rcar_gen4_pcie *rcar)
 {
-	rcar->mode = (uintptr_t)of_device_get_match_data(&rcar->pdev->dev);
+	rcar->drvdata = of_device_get_match_data(&rcar->pdev->dev);
+	if (!rcar->drvdata)
+		return -EINVAL;
 
-	switch (rcar->mode) {
+	switch (rcar->drvdata->mode) {
 	case DW_PCIE_RC_TYPE:
 		return rcar_gen4_add_dw_pcie_rp(rcar);
 	case DW_PCIE_EP_TYPE:
@@ -494,7 +517,7 @@ err_unprepare:
 
 static void rcar_gen4_remove_dw_pcie(struct rcar_gen4_pcie *rcar)
 {
-	switch (rcar->mode) {
+	switch (rcar->drvdata->mode) {
 	case DW_PCIE_RC_TYPE:
 		rcar_gen4_remove_dw_pcie_rp(rcar);
 		break;
@@ -514,14 +537,227 @@ static void rcar_gen4_pcie_remove(struct platform_device *pdev)
 	rcar_gen4_pcie_unprepare(rcar);
 }
 
+static int r8a779f0_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable)
+{
+	u32 val;
+
+	val = readl(rcar->base + PCIERSTCTRL1);
+	if (enable) {
+		val |= APP_LTSSM_ENABLE;
+		val &= ~APP_HOLD_PHY_RST;
+	} else {
+		/*
+		 * Since the datasheet of R-Car doesn't mention how to assert
+		 * the APP_HOLD_PHY_RST, don't assert it again. Otherwise,
+		 * hang-up issue happened in the dw_edma_core_off() when
+		 * the controller didn't detect a PCI device.
+		 */
+		val &= ~APP_LTSSM_ENABLE;
+	}
+	writel(val, rcar->base + PCIERSTCTRL1);
+
+	return 0;
+}
+
+static void rcar_gen4_pcie_additional_common_init(struct rcar_gen4_pcie *rcar)
+{
+	struct dw_pcie *dw = &rcar->dw;
+	u32 val;
+
+	val = dw_pcie_readl_dbi(dw, PCIE_PORT_LANE_SKEW);
+	val &= ~PORT_LANE_SKEW_INSERT_MASK;
+	if (dw->num_lanes < 4)
+		val |= BIT(6);
+	dw_pcie_writel_dbi(dw, PCIE_PORT_LANE_SKEW, val);
+
+	val = readl(rcar->base + PCIEPWRMNGCTRL);
+	val |= APP_CLK_REQ_N | APP_CLK_PM_EN;
+	writel(val, rcar->base + PCIEPWRMNGCTRL);
+}
+
+static void rcar_gen4_pcie_phy_reg_update_bits(struct rcar_gen4_pcie *rcar,
+					       u32 offset, u32 mask, u32 val)
+{
+	u32 tmp;
+
+	tmp = readl(rcar->phy_base + offset);
+	tmp &= ~mask;
+	tmp |= val;
+	writel(tmp, rcar->phy_base + offset);
+}
+
+/*
+ * SoC datasheet suggests checking port logic register bits during firmware
+ * write. If read returns non-zero value, then this function returns -EAGAIN
+ * indicating that the write needs to be done again. If read returns zero,
+ * then return 0 to indicate success.
+ */
+static int rcar_gen4_pcie_reg_test_bit(struct rcar_gen4_pcie *rcar,
+				       u32 offset, u32 mask)
+{
+	struct dw_pcie *dw = &rcar->dw;
+
+	if (dw_pcie_readl_dbi(dw, offset) & mask)
+		return -EAGAIN;
+
+	return 0;
+}
+
+static int rcar_gen4_pcie_download_phy_firmware(struct rcar_gen4_pcie *rcar)
+{
+	/* The check_addr values are magical numbers in the datasheet */
+	const u32 check_addr[] = { 0x00101018, 0x00101118, 0x00101021, 0x00101121};
+	struct dw_pcie *dw = &rcar->dw;
+	const struct firmware *fw;
+	unsigned int i, timeout;
+	u32 data;
+	int ret;
+
+	ret = request_firmware(&fw, RCAR_GEN4_PCIE_FIRMWARE_NAME, dw->dev);
+	if (ret) {
+		dev_err(dw->dev, "Failed to load firmware (%s): %d\n",
+			RCAR_GEN4_PCIE_FIRMWARE_NAME, ret);
+		return ret;
+	}
+
+	for (i = 0; i < (fw->size / 2); i++) {
+		data = fw->data[(i * 2) + 1] << 8 | fw->data[i * 2];
+		timeout = 100;
+		do {
+			dw_pcie_writel_dbi(dw, PRTLGC89, RCAR_GEN4_PCIE_FIRMWARE_BASE_ADDR + i);
+			dw_pcie_writel_dbi(dw, PRTLGC90, data);
+			if (!rcar_gen4_pcie_reg_test_bit(rcar, PRTLGC89, BIT(30)))
+				break;
+			if (!(--timeout)) {
+				ret = -ETIMEDOUT;
+				goto exit;
+			}
+			usleep_range(100, 200);
+		} while (1);
+	}
+
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x0f8, BIT(17), BIT(17));
+
+	for (i = 0; i < ARRAY_SIZE(check_addr); i++) {
+		timeout = 100;
+		do {
+			dw_pcie_writel_dbi(dw, PRTLGC89, check_addr[i]);
+			ret = rcar_gen4_pcie_reg_test_bit(rcar, PRTLGC89, BIT(30));
+			ret |= rcar_gen4_pcie_reg_test_bit(rcar, PRTLGC90, BIT(0));
+			if (!ret)
+				break;
+			if (!(--timeout)) {
+				ret = -ETIMEDOUT;
+				goto exit;
+			}
+			usleep_range(100, 200);
+		} while (1);
+	}
+
+exit:
+	release_firmware(fw);
+
+	return ret;
+}
+
+static int rcar_gen4_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable)
+{
+	struct dw_pcie *dw = &rcar->dw;
+	u32 val;
+	int ret;
+
+	if (!enable) {
+		val = readl(rcar->base + PCIERSTCTRL1);
+		val &= ~APP_LTSSM_ENABLE;
+		writel(val, rcar->base + PCIERSTCTRL1);
+
+		return 0;
+	}
+
+	val = dw_pcie_readl_dbi(dw, PCIE_PORT_FORCE);
+	val |= PORT_FORCE_DO_DESKEW_FOR_SRIS;
+	dw_pcie_writel_dbi(dw, PCIE_PORT_FORCE, val);
+
+	val = readl(rcar->base + PCIEMSR0);
+	val |= APP_SRIS_MODE;
+	writel(val, rcar->base + PCIEMSR0);
+
+	/*
+	 * The R-Car Gen4 datasheet doesn't describe the PHY registers' name.
+	 * But, the initialization procedure describes these offsets. So,
+	 * this driver has magical offset numbers.
+	 */
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x700, BIT(28), 0);
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x700, BIT(20), 0);
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x700, BIT(12), 0);
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x700, BIT(4), 0);
+
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x148, GENMASK(23, 22), BIT(22));
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x148, GENMASK(18, 16), GENMASK(17, 16));
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x148, GENMASK(7, 6), BIT(6));
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x148, GENMASK(2, 0), GENMASK(11, 0));
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x1d4, GENMASK(16, 15), GENMASK(16, 15));
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x514, BIT(26), BIT(26));
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x0f8, BIT(16), 0);
+	rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x0f8, BIT(19), BIT(19));
+
+	val = readl(rcar->base + PCIERSTCTRL1);
+	val &= ~APP_HOLD_PHY_RST;
+	writel(val, rcar->base + PCIERSTCTRL1);
+
+	ret = readl_poll_timeout(rcar->phy_base + 0x0f8, val, !(val & BIT(18)), 100, 10000);
+	if (ret < 0)
+		return ret;
+
+	ret = rcar_gen4_pcie_download_phy_firmware(rcar);
+	if (ret)
+		return ret;
+
+	val = readl(rcar->base + PCIERSTCTRL1);
+	val |= APP_LTSSM_ENABLE;
+	writel(val, rcar->base + PCIERSTCTRL1);
+
+	return 0;
+}
+
+static struct rcar_gen4_pcie_drvdata drvdata_r8a779f0_pcie = {
+	.ltssm_control = r8a779f0_pcie_ltssm_control,
+	.mode = DW_PCIE_RC_TYPE,
+};
+
+static struct rcar_gen4_pcie_drvdata drvdata_r8a779f0_pcie_ep = {
+	.ltssm_control = r8a779f0_pcie_ltssm_control,
+	.mode = DW_PCIE_EP_TYPE,
+};
+
+static struct rcar_gen4_pcie_drvdata drvdata_rcar_gen4_pcie = {
+	.additional_common_init = rcar_gen4_pcie_additional_common_init,
+	.ltssm_control = rcar_gen4_pcie_ltssm_control,
+	.mode = DW_PCIE_RC_TYPE,
+};
+
+static struct rcar_gen4_pcie_drvdata drvdata_rcar_gen4_pcie_ep = {
+	.additional_common_init = rcar_gen4_pcie_additional_common_init,
+	.ltssm_control = rcar_gen4_pcie_ltssm_control,
+	.mode = DW_PCIE_EP_TYPE,
+};
+
 static const struct of_device_id rcar_gen4_pcie_of_match[] = {
 	{
+		.compatible = "renesas,r8a779f0-pcie",
+		.data = &drvdata_r8a779f0_pcie,
+	},
+	{
+		.compatible = "renesas,r8a779f0-pcie-ep",
+		.data = &drvdata_r8a779f0_pcie_ep,
+	},
+	{
 		.compatible = "renesas,rcar-gen4-pcie",
-		.data = (void *)DW_PCIE_RC_TYPE,
+		.data = &drvdata_rcar_gen4_pcie,
 	},
 	{
 		.compatible = "renesas,rcar-gen4-pcie-ep",
-		.data = (void *)DW_PCIE_EP_TYPE,
+		.data = &drvdata_rcar_gen4_pcie_ep,
 	},
 	{},
 };