PCI: dwc: artpec6: Add support for the ARTPEC-7 SoC

Add support for	the ARTPEC-7 SoC in the	artpec6	driver.
The ARTPEC-6 SoC and the ARTPEC-7 SoC are very similar.
Unfortunately, some fields in the PCIECFG and PCIESTAT
register have changed.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

drivers/pci/dwc/pcie-artpec6.c

@@ -27,14 +27,21 @@
 
 #define to_artpec6_pcie(x)	dev_get_drvdata((x)->dev)
 
+enum artpec_pcie_variants {
+	ARTPEC6,
+	ARTPEC7,
+};
+
 struct artpec6_pcie {
 	struct dw_pcie		*pci;
 	struct regmap		*regmap;	/* DT axis,syscon-pcie */
 	void __iomem		*phy_base;	/* DT phy */
+	enum artpec_pcie_variants variant;
 	enum dw_pcie_device_mode mode;
 };
 
 struct artpec_pcie_of_data {
+	enum artpec_pcie_variants variant;
 	enum dw_pcie_device_mode mode;
 };
 
@@ -43,6 +50,13 @@ static const struct of_device_id artpec6_pcie_of_match[];
 /* PCIe Port Logic registers (memory-mapped) */
 #define PL_OFFSET			0x700
 
+#define ACK_F_ASPM_CTRL_OFF		(PL_OFFSET + 0xc)
+#define ACK_N_FTS_MASK			GENMASK(15, 8)
+#define ACK_N_FTS(x)			(((x) << 8) & ACK_N_FTS_MASK)
+
+#define FAST_TRAINING_SEQ_MASK		GENMASK(7, 0)
+#define FAST_TRAINING_SEQ(x)		(((x) << 0) & FAST_TRAINING_SEQ_MASK)
+
 /* ARTPEC-6 specific registers */
 #define PCIECFG				0x18
 #define  PCIECFG_DBG_OEN		BIT(24)
@@ -57,6 +71,13 @@ static const struct of_device_id artpec6_pcie_of_match[];
 #define  PCIECFG_MODE_TX_DRV_EN		BIT(3)
 #define  PCIECFG_CISRREN		BIT(2)
 #define  PCIECFG_MACRO_ENABLE		BIT(0)
+/* ARTPEC-7 specific fields */
+#define  PCIECFG_REFCLKSEL		BIT(23)
+#define  PCIECFG_NOC_RESET		BIT(3)
+
+#define PCIESTAT			0x1c
+/* ARTPEC-7 specific fields */
+#define  PCIESTAT_EXTREFCLK		BIT(3)
 
 #define NOCCFG				0x40
 #define  NOCCFG_ENABLE_CLK_PCIE		BIT(4)
@@ -67,6 +88,12 @@ static const struct of_device_id artpec6_pcie_of_match[];
 #define PHY_STATUS			0x118
 #define  PHY_COSPLLLOCK			BIT(0)
 
+#define PHY_TX_ASIC_OUT			0x4040
+#define  PHY_TX_ASIC_OUT_TX_ACK		BIT(0)
+
+#define PHY_RX_ASIC_OUT			0x405c
+#define  PHY_RX_ASIC_OUT_ACK		BIT(0)
+
 static u32 artpec6_pcie_readl(struct artpec6_pcie *artpec6_pcie, u32 offset)
 {
 	u32 val;
@@ -125,7 +152,7 @@ static const struct dw_pcie_ops dw_pcie_ops = {
 	.stop_link = artpec6_pcie_stop_link,
 };
 
-static void artpec6_pcie_wait_for_phy(struct artpec6_pcie *artpec6_pcie)
+static void artpec6_pcie_wait_for_phy_a6(struct artpec6_pcie *artpec6_pcie)
 {
 	struct dw_pcie *pci = artpec6_pcie->pci;
 	struct device *dev = pci->dev;
@@ -152,7 +179,49 @@ static void artpec6_pcie_wait_for_phy(struct artpec6_pcie *artpec6_pcie)
 		dev_err(dev, "PHY PLL did not lock\n");
 }
 
-static void artpec6_pcie_init_phy(struct artpec6_pcie *artpec6_pcie)
+static void artpec6_pcie_wait_for_phy_a7(struct artpec6_pcie *artpec6_pcie)
+{
+	struct dw_pcie *pci = artpec6_pcie->pci;
+	struct device *dev = pci->dev;
+	u32 val;
+	u16 phy_status_tx, phy_status_rx;
+	unsigned int retries;
+
+	retries = 50;
+	do {
+		usleep_range(1000, 2000);
+		val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
+		retries--;
+	} while (retries &&
+		(val & (NOCCFG_POWER_PCIE_IDLEACK | NOCCFG_POWER_PCIE_IDLE)));
+	if (!retries)
+		dev_err(dev, "PCIe clock manager did not leave idle state\n");
+
+	retries = 50;
+	do {
+		usleep_range(1000, 2000);
+		phy_status_tx = readw(artpec6_pcie->phy_base + PHY_TX_ASIC_OUT);
+		phy_status_rx = readw(artpec6_pcie->phy_base + PHY_RX_ASIC_OUT);
+		retries--;
+	} while (retries && ((phy_status_tx & PHY_TX_ASIC_OUT_TX_ACK) ||
+				(phy_status_rx & PHY_RX_ASIC_OUT_ACK)));
+	if (!retries)
+		dev_err(dev, "PHY did not enter Pn state\n");
+}
+
+static void artpec6_pcie_wait_for_phy(struct artpec6_pcie *artpec6_pcie)
+{
+	switch (artpec6_pcie->variant) {
+	case ARTPEC6:
+		artpec6_pcie_wait_for_phy_a6(artpec6_pcie);
+		break;
+	case ARTPEC7:
+		artpec6_pcie_wait_for_phy_a7(artpec6_pcie);
+		break;
+	}
+}
+
+static void artpec6_pcie_init_phy_a6(struct artpec6_pcie *artpec6_pcie)
 {
 	u32 val;
 
@@ -182,12 +251,90 @@ static void artpec6_pcie_init_phy(struct artpec6_pcie *artpec6_pcie)
 	artpec6_pcie_writel(artpec6_pcie, NOCCFG, val);
 }
 
+static void artpec6_pcie_init_phy_a7(struct artpec6_pcie *artpec6_pcie)
+{
+	struct dw_pcie *pci = artpec6_pcie->pci;
+	u32 val;
+	bool extrefclk;
+
+	/* Check if external reference clock is connected */
+	val = artpec6_pcie_readl(artpec6_pcie, PCIESTAT);
+	extrefclk = !!(val & PCIESTAT_EXTREFCLK);
+	dev_dbg(pci->dev, "Using reference clock: %s\n",
+		extrefclk ? "external" : "internal");
+
+	val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
+	val |=  PCIECFG_RISRCREN |	/* Receiver term. 50 Ohm */
+		PCIECFG_PCLK_ENABLE;
+	if (extrefclk)
+		val |= PCIECFG_REFCLKSEL;
+	else
+		val &= ~PCIECFG_REFCLKSEL;
+	artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
+	usleep_range(10, 20);
+
+	val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
+	val |= NOCCFG_ENABLE_CLK_PCIE;
+	artpec6_pcie_writel(artpec6_pcie, NOCCFG, val);
+	usleep_range(20, 30);
+
+	val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
+	val &= ~NOCCFG_POWER_PCIE_IDLEREQ;
+	artpec6_pcie_writel(artpec6_pcie, NOCCFG, val);
+}
+
+static void artpec6_pcie_init_phy(struct artpec6_pcie *artpec6_pcie)
+{
+	switch (artpec6_pcie->variant) {
+	case ARTPEC6:
+		artpec6_pcie_init_phy_a6(artpec6_pcie);
+		break;
+	case ARTPEC7:
+		artpec6_pcie_init_phy_a7(artpec6_pcie);
+		break;
+	}
+}
+
+static void artpec6_pcie_set_nfts(struct artpec6_pcie *artpec6_pcie)
+{
+	struct dw_pcie *pci = artpec6_pcie->pci;
+	u32 val;
+
+	if (artpec6_pcie->variant != ARTPEC7)
+		return;
+
+	/*
+	 * Increase the N_FTS (Number of Fast Training Sequences)
+	 * to be transmitted when transitioning from L0s to L0.
+	 */
+	val = dw_pcie_readl_dbi(pci, ACK_F_ASPM_CTRL_OFF);
+	val &= ~ACK_N_FTS_MASK;
+	val |= ACK_N_FTS(180);
+	dw_pcie_writel_dbi(pci, ACK_F_ASPM_CTRL_OFF, val);
+
+	/*
+	 * Set the Number of Fast Training Sequences that the core
+	 * advertises as its N_FTS during Gen2 or Gen3 link training.
+	 */
+	val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
+	val &= ~FAST_TRAINING_SEQ_MASK;
+	val |= FAST_TRAINING_SEQ(180);
+	dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, val);
+}
+
 static void artpec6_pcie_assert_core_reset(struct artpec6_pcie *artpec6_pcie)
 {
 	u32 val;
 
 	val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
-	val |= PCIECFG_CORE_RESET_REQ;
+	switch (artpec6_pcie->variant) {
+	case ARTPEC6:
+		val |= PCIECFG_CORE_RESET_REQ;
+		break;
+	case ARTPEC7:
+		val &= ~PCIECFG_NOC_RESET;
+		break;
+	}
 	artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
 }
 
@@ -196,7 +343,14 @@ static void artpec6_pcie_deassert_core_reset(struct artpec6_pcie *artpec6_pcie)
 	u32 val;
 
 	val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
-	val &= ~PCIECFG_CORE_RESET_REQ;
+	switch (artpec6_pcie->variant) {
+	case ARTPEC6:
+		val &= ~PCIECFG_CORE_RESET_REQ;
+		break;
+	case ARTPEC7:
+		val |= PCIECFG_NOC_RESET;
+		break;
+	}
 	artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
 	usleep_range(100, 200);
 }
@@ -219,6 +373,7 @@ static int artpec6_pcie_host_init(struct pcie_port *pp)
 	artpec6_pcie_init_phy(artpec6_pcie);
 	artpec6_pcie_deassert_core_reset(artpec6_pcie);
 	artpec6_pcie_wait_for_phy(artpec6_pcie);
+	artpec6_pcie_set_nfts(artpec6_pcie);
 	dw_pcie_setup_rc(pp);
 	artpec6_pcie_establish_link(pci);
 	dw_pcie_wait_for_link(pci);
@@ -287,6 +442,7 @@ static void artpec6_pcie_ep_init(struct dw_pcie_ep *ep)
 	artpec6_pcie_init_phy(artpec6_pcie);
 	artpec6_pcie_deassert_core_reset(artpec6_pcie);
 	artpec6_pcie_wait_for_phy(artpec6_pcie);
+	artpec6_pcie_set_nfts(artpec6_pcie);
 
 	for (bar = BAR_0; bar <= BAR_5; bar++)
 		dw_pcie_ep_reset_bar(pci, bar);
@@ -358,6 +514,7 @@ static int artpec6_pcie_probe(struct platform_device *pdev)
 	int ret;
 	const struct of_device_id *match;
 	const struct artpec_pcie_of_data *data;
+	enum artpec_pcie_variants variant;
 	enum dw_pcie_device_mode mode;
 
 	match = of_match_device(artpec6_pcie_of_match, dev);
@@ -365,6 +522,7 @@ static int artpec6_pcie_probe(struct platform_device *pdev)
 		return -EINVAL;
 
 	data = (struct artpec_pcie_of_data *)match->data;
+	variant = (enum artpec_pcie_variants)data->variant;
 	mode = (enum dw_pcie_device_mode)data->mode;
 
 	artpec6_pcie = devm_kzalloc(dev, sizeof(*artpec6_pcie), GFP_KERNEL);
@@ -379,6 +537,7 @@ static int artpec6_pcie_probe(struct platform_device *pdev)
 	pci->ops = &dw_pcie_ops;
 
 	artpec6_pcie->pci = pci;
+	artpec6_pcie->variant = variant;
 	artpec6_pcie->mode = mode;
 
 	dbi_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
@@ -430,10 +589,22 @@ static int artpec6_pcie_probe(struct platform_device *pdev)
 }
 
 static const struct artpec_pcie_of_data artpec6_pcie_rc_of_data = {
+	.variant = ARTPEC6,
 	.mode = DW_PCIE_RC_TYPE,
 };
 
 static const struct artpec_pcie_of_data artpec6_pcie_ep_of_data = {
+	.variant = ARTPEC6,
+	.mode = DW_PCIE_EP_TYPE,
+};
+
+static const struct artpec_pcie_of_data artpec7_pcie_rc_of_data = {
+	.variant = ARTPEC7,
+	.mode = DW_PCIE_RC_TYPE,
+};
+
+static const struct artpec_pcie_of_data artpec7_pcie_ep_of_data = {
+	.variant = ARTPEC7,
 	.mode = DW_PCIE_EP_TYPE,
 };
 
@@ -446,6 +617,14 @@ static const struct of_device_id artpec6_pcie_of_match[] = {
 		.compatible = "axis,artpec6-pcie-ep",
 		.data = &artpec6_pcie_ep_of_data,
 	},
+	{
+		.compatible = "axis,artpec7-pcie",
+		.data = &artpec7_pcie_rc_of_data,
+	},
+	{
+		.compatible = "axis,artpec7-pcie-ep",
+		.data = &artpec7_pcie_ep_of_data,
+	},
 	{},
 };