Thread (17 messages) 17 messages, 3 authors, 2020-07-07
STALE2198d LANDED: 7 (7M)
Revisions (4)
  1. v3 [diff vs current]
  2. v5 [diff vs current]
  3. v6 [diff vs current]
  4. v7 current

[PATCH v7 11/12] PCI: qcom: Support pci speed set for ipq806x

From: Ansuel Smith <ansuelsmth@gmail.com>
Date: 2020-06-15 21:06:59
Also in: linux-arm-msm, linux-pci, lkml
Subsystem: arm/qualcomm mailing list, pci native host bridge and endpoint drivers, pci subsystem, pcie driver for qualcomm msm, the rest · Maintainers: Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds

From: Sham Muthayyan <redacted>

Some SoC based on ipq8064/5 needs to be limited to pci GEN1 speed due to
some hardware limitations. Add support for speed setting defined by the
max-link-speed binding. If not defined the max speed is set to GEN2 by
default.

Signed-off-by: Sham Muthayyan <redacted>
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 259b627bf890..c40921589122 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -27,6 +27,7 @@
 #include <linux/slab.h>
 #include <linux/types.h>
 
+#include "../../pci.h"
 #include "pcie-designware.h"
 
 #define PCIE20_PARF_SYS_CTRL			0x00
@@ -99,6 +100,8 @@
 #define PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE	0x358
 #define SLV_ADDR_SPACE_SZ			0x10000000
 
+#define PCIE20_LNK_CONTROL2_LINK_STATUS2	0xa0
+
 #define DEVICE_TYPE_RC				0x4
 
 #define QCOM_PCIE_2_1_0_MAX_SUPPLY	3
@@ -195,6 +198,7 @@ struct qcom_pcie {
 	struct phy *phy;
 	struct gpio_desc *reset;
 	const struct qcom_pcie_ops *ops;
+	int gen;
 };
 
 #define to_qcom_pcie(x)		dev_get_drvdata((x)->dev)
@@ -395,6 +399,11 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie)
 	/* wait for clock acquisition */
 	usleep_range(1000, 1500);
 
+	if (pcie->gen == 1) {
+		val = readl(pci->dbi_base + PCIE20_LNK_CONTROL2_LINK_STATUS2);
+		val |= PCI_EXP_LNKSTA_CLS_2_5GB;
+		writel(val, pci->dbi_base + PCIE20_LNK_CONTROL2_LINK_STATUS2);
+	}
 
 	/* Set the Max TLP size to 2K, instead of using default of 4K */
 	writel(CFG_REMOTE_RD_REQ_BRIDGE_SIZE_2K,
@@ -1397,6 +1406,10 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 		goto err_pm_runtime_put;
 	}
 
+	pcie->gen = of_pci_get_max_link_speed(pdev->dev.of_node);
+	if (pcie->gen < 0)
+		pcie->gen = 2;
+
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "parf");
 	pcie->parf = devm_ioremap_resource(dev, res);
 	if (IS_ERR(pcie->parf)) {
-- 
2.27.0.rc0
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