[PATCH v2 2/6] PCI: qcom: add support for IPQ60xx PCIe controller

[Baruch Siach <baruch@tkos.co.il>]

From: Selvam Sathappan Periakaruppan <speriaka@codeaurora.org>

IPQ60xx series of SoCs have one port of PCIe gen 3. Add support for that
platform.

The code is based on downstream Codeaurora kernel v5.4. Split out the
DBI registers access part from .init into .post_init. DBI registers are
only accessible after phy_power_on().

Signed-off-by: Selvam Sathappan Periakaruppan <speriaka@codeaurora.org>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
v2:
  * Drop ATU configuration; rely on common code instead

  * Use more common register macros

  * Use bulk clk and reset APIs
---
 drivers/pci/controller/dwc/pcie-designware.h |   1 +
 drivers/pci/controller/dwc/pcie-qcom.c       | 150 +++++++++++++++++++
 2 files changed, 151 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index ceb359b6e6a6..346462c74a3e 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -76,6 +76,7 @@
 
 #define GEN3_RELATED_OFF			0x890
 #define GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL	BIT(0)
+#define GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS	BIT(13)
 #define GEN3_RELATED_OFF_GEN3_EQ_DISABLE	BIT(16)
 #define GEN3_RELATED_OFF_RATE_SHADOW_SEL_SHIFT	24
 #define GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK	GENMASK(25, 24)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 8a7a300163e5..93766aee3e7c 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -52,6 +52,10 @@
 #define PCIE20_PARF_DBI_BASE_ADDR		0x168
 #define PCIE20_PARF_SLV_ADDR_SPACE_SIZE		0x16C
 #define PCIE20_PARF_MHI_CLOCK_RESET_CTRL	0x174
+#define AHB_CLK_EN				BIT(0)
+#define MSTR_AXI_CLK_EN				BIT(1)
+#define BYPASS					BIT(4)
+
 #define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT	0x178
 #define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2	0x1A8
 #define PCIE20_PARF_LTSSM			0x1B0
@@ -94,6 +98,12 @@
 #define SLV_ADDR_SPACE_SZ			0x10000000
 
 #define PCIE20_LNK_CONTROL2_LINK_STATUS2	0xa0
+#define PCIE_CAP_CURR_DEEMPHASIS		BIT(16)
+#define SPEED_GEN1				0x1
+#define SPEED_GEN2				0x2
+#define SPEED_GEN3				0x3
+#define AXI_CLK_RATE				200000000
+#define RCHNG_CLK_RATE				100000000
 
 #define DEVICE_TYPE_RC				0x4
 
@@ -168,6 +178,11 @@ struct qcom_pcie_resources_2_7_0 {
 	struct clk *pipe_clk;
 };
 
+struct qcom_pcie_resources_2_9_0 {
+	struct clk_bulk_data clks[5];
+	struct reset_control *rst;
+};
+
 union qcom_pcie_resources {
 	struct qcom_pcie_resources_1_0_0 v1_0_0;
 	struct qcom_pcie_resources_2_1_0 v2_1_0;
@@ -175,6 +190,7 @@ union qcom_pcie_resources {
 	struct qcom_pcie_resources_2_3_3 v2_3_3;
 	struct qcom_pcie_resources_2_4_0 v2_4_0;
 	struct qcom_pcie_resources_2_7_0 v2_7_0;
+	struct qcom_pcie_resources_2_9_0 v2_9_0;
 };
 
 struct qcom_pcie;
@@ -1266,6 +1282,130 @@ static void qcom_pcie_post_deinit_2_7_0(struct qcom_pcie *pcie)
 	clk_disable_unprepare(res->pipe_clk);
 }
 
+static int qcom_pcie_get_resources_2_9_0(struct qcom_pcie *pcie)
+{
+	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
+	struct dw_pcie *pci = pcie->pci;
+	struct device *dev = pci->dev;
+	int ret;
+
+	res->clks[0].id = "iface";
+	res->clks[1].id = "axi_m";
+	res->clks[2].id = "axi_s";
+	res->clks[3].id = "axi_bridge";
+	res->clks[4].id = "rchng";
+
+	ret = devm_clk_bulk_get(dev, ARRAY_SIZE(res->clks), res->clks);
+	if (ret < 0)
+		return ret;
+
+	res->rst = devm_reset_control_array_get_exclusive(dev);
+	if (IS_ERR(res->rst))
+		return PTR_ERR(res->rst);
+
+	return 0;
+}
+
+static void qcom_pcie_deinit_2_9_0(struct qcom_pcie *pcie)
+{
+	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
+
+	clk_bulk_disable_unprepare(ARRAY_SIZE(res->clks), res->clks);
+}
+
+static int qcom_pcie_init_2_9_0(struct qcom_pcie *pcie)
+{
+	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
+	struct device *dev = pcie->pci->dev;
+	int ret;
+
+	ret = reset_control_assert(res->rst);
+	if (ret) {
+		dev_err(dev, "reset assert failed (%d)\n", ret);
+		return ret;
+	}
+
+	usleep_range(2000, 2500);
+
+	ret = reset_control_deassert(res->rst);
+	if (ret) {
+		dev_err(dev, "reset deassert failed (%d)\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Don't have a way to see if the reset has completed.
+	 * Wait for some time.
+	 */
+	usleep_range(2000, 2500);
+
+	ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks);
+	if (ret)
+		goto err_reset;
+
+	return 0;
+
+	/*
+	 * Not checking for failure, will anyway return
+	 * the original failure in 'ret'.
+	 */
+err_reset:
+	reset_control_assert(res->rst);
+
+	return ret;
+}
+
+static int qcom_pcie_post_init_2_9_0(struct qcom_pcie *pcie)
+{
+	struct dw_pcie *pci = pcie->pci;
+	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	u32 val;
+	int i;
+
+	writel(SLV_ADDR_SPACE_SZ,
+		pcie->parf + PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE);
+
+	val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
+	val &= ~BIT(0);
+	writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
+
+	writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
+
+	writel(DEVICE_TYPE_RC, pcie->parf + PCIE20_PARF_DEVICE_TYPE);
+	writel(BYPASS | MSTR_AXI_CLK_EN | AHB_CLK_EN,
+		pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
+	writel(GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS
+		| GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL,
+		pci->dbi_base + GEN3_RELATED_OFF);
+
+	writel(MST_WAKEUP_EN | SLV_WAKEUP_EN | MSTR_ACLK_CGC_DIS
+		| SLV_ACLK_CGC_DIS | CORE_CLK_CGC_DIS |
+		AUX_PWR_DET | L23_CLK_RMV_DIS | L1_CLK_RMV_DIS,
+		pcie->parf + PCIE20_PARF_SYS_CTRL);
+
+	writel(0, pcie->parf + PCIE20_PARF_Q2A_FLUSH);
+
+	dw_pcie_dbi_ro_wr_en(pci);
+	writel(PCIE_CAP_LINK1_VAL, pci->dbi_base + offset + PCI_EXP_SLTCAP);
+
+	/* Configure PCIe link capabilities for ASPM */
+	val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP);
+	val &= ~PCI_EXP_LNKCAP_ASPMS;
+	writel(val, pci->dbi_base + offset + PCI_EXP_LNKCAP);
+
+	writel(PCI_EXP_DEVCTL2_COMP_TMOUT_DIS, pci->dbi_base + offset +
+			PCI_EXP_DEVCTL2);
+
+	writel(PCIE_CAP_CURR_DEEMPHASIS | SPEED_GEN3,
+			pci->dbi_base + offset + PCI_EXP_DEVCTL2);
+
+	for (i = 0;i < 256;i++)
+		writel(0x0, pcie->parf + PCIE20_PARF_BDF_TO_SID_TABLE_N
+				+ (4 * i));
+
+	return 0;
+}
+
 static int qcom_pcie_link_up(struct dw_pcie *pci)
 {
 	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
@@ -1456,6 +1596,15 @@ static const struct qcom_pcie_ops ops_1_9_0 = {
 	.config_sid = qcom_pcie_config_sid_sm8250,
 };
 
+/* Qcom IP rev.: 2.9.0  Synopsys IP rev.: 5.00a */
+static const struct qcom_pcie_ops ops_2_9_0 = {
+	.get_resources = qcom_pcie_get_resources_2_9_0,
+	.init = qcom_pcie_init_2_9_0,
+	.post_init = qcom_pcie_post_init_2_9_0,
+	.deinit = qcom_pcie_deinit_2_9_0,
+	.ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
+};
+
 static const struct dw_pcie_ops dw_pcie_ops = {
 	.link_up = qcom_pcie_link_up,
 	.start_link = qcom_pcie_start_link,
@@ -1555,6 +1704,7 @@ static const struct of_device_id qcom_pcie_match[] = {
 	{ .compatible = "qcom,pcie-qcs404", .data = &ops_2_4_0 },
 	{ .compatible = "qcom,pcie-sdm845", .data = &ops_2_7_0 },
 	{ .compatible = "qcom,pcie-sm8250", .data = &ops_1_9_0 },
+	{ .compatible = "qcom,pcie-ipq6018", .data = &ops_2_9_0 },
 	{ }
 };
 
-- 
2.30.2