[PATCH v2 2/2] pci: host: new driver for Marvell Armada 7K/8K PCIe controller

Thomas Petazzoni
2016-04-14T15:36:17Z

The Marvell Armada 7K/8K SoCs integrate a PCIe controller from
Synopsys. This commit adds a new driver that provides the small glue
needed to use the existing Designware driver to make it work on
Marvell Armada 7K/8K SoCs.

The MSI support will be enabled at a later point.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
drivers/pci/host/Kconfig | 11 ++
drivers/pci/host/Makefile | 1 +
drivers/pci/host/pcie-armada8k.c | 261 +++++++++++++++++++++++++++++++++++++++
3 files changed, 273 insertions(+)
create mode 100644 drivers/pci/host/pcie-armada8k.c

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 7a0780d..a3b6f24 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -231,4 +231,15 @@ config PCI_HOST_THUNDER_ECAM
help
Say Y here if you want ECAM support for CN88XX-Pass-1.x Cavium Thunder SoCs.

+config PCIE_ARMADA_8K
+ bool "Marvell Armada-8K PCIe controller"
+ depends on ARCH_MVEBU
+ select PCIE_DW
+ select PCIEPORTBUS
+ help
+ Say Y here if you want to enable PCIe controller support on
+ Armada-8K SoCs. The PCIe controller on Armada-8K is based on
+ Designware hardware and therefore the driver re-uses the
+ Designware core functions to implement the driver.
+
endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index d85b5fa..a6f85e3 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -28,3 +28,4 @@ obj-$(CONFIG_PCI_HISI) += pcie-hisi.o
obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
obj-$(CONFIG_PCI_HOST_THUNDER_ECAM) += pci-thunder-ecam.o
obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o
+obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
diff --git a/drivers/pci/host/pcie-armada8k.c b/drivers/pci/host/pcie-armada8k.c
new file mode 100644
index 0000000..7569302
--- /dev/null
+++ b/drivers/pci/host/pcie-armada8k.c
@@ -0,0 +1,261 @@
+/*
+ * PCIe host controller driver for Marvell Armada-8K SoCs
+ *
+ * Armada-8K PCIe Glue Layer Source Code
+ *
+ * Copyright (C) 2016 Marvell Technology Group Ltd.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#define pr_fmt(fmt) "armada-8k-pcie: " fmt
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pci.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/resource.h>
+#include <linux/of_pci.h>
+#include <linux/of_irq.h>
+
+#include "pcie-designware.h"
+
+struct armada8k_pcie {
+ void __iomem *base;
+ struct clk *clk;
+ struct pcie_port pp;
+};
+
+#define PCIE_VENDOR_REGS_OFFSET 0x8000
+
+#define PCIE_GLOBAL_CONTROL_REG 0x0
+#define PCIE_APP_LTSSM_EN BIT(2)
+#define PCIE_DEVICE_TYPE_SHIFT 4
+#define PCIE_DEVICE_TYPE_MASK 0xF
+#define PCIE_DEVICE_TYPE_EP 0x0 /* Endpoint */
+#define PCIE_DEVICE_TYPE_LEP 0x1 /* Legacy endpoint */
+#define PCIE_DEVICE_TYPE_RC 0x4 /* Root complex */
+
+#define PCIE_GLOBAL_STATUS_REG 0x8
+#define PCIE_GLB_STS_RDLH_LINK_UP BIT(1)
+#define PCIE_GLB_STS_PHY_LINK_UP BIT(9)
+
+#define PCIE_GLOBAL_INT_CAUSE1_REG 0x1C
+#define PCIE_GLOBAL_INT_MASK1_REG 0x20
+#define PCIE_INT_A_ASSERT_MASK BIT(9)
+#define PCIE_INT_B_ASSERT_MASK BIT(10)
+#define PCIE_INT_C_ASSERT_MASK BIT(11)
+#define PCIE_INT_D_ASSERT_MASK BIT(12)
+
+#define PCIE_ARCACHE_TRC_REG 0x50
+#define PCIE_AWCACHE_TRC_REG 0x54
+#define PCIE_ARUSER_REG 0x5C
+#define PCIE_AWUSER_REG 0x60
+/*
+ * AR/AW Cache defauls: Normal memory, Write-Back, Read / Write
+ * allocate
+ */
+#define ARCACHE_DEFAULT_VALUE 0x3511
+#define AWCACHE_DEFAULT_VALUE 0x5311
+
+#define DOMAIN_OUTER_SHAREABLE 0x2
+#define AX_USER_DOMAIN_MASK 0x3
+#define AX_USER_DOMAIN_SHIFT 4
+
+
+
+#define to_armada8k_pcie(x) container_of(x, struct armada8k_pcie, pp)
+
+static int armada8k_pcie_link_up(struct pcie_port *pp)
+{
+ u32 reg;
+ struct armada8k_pcie *pcie = to_armada8k_pcie(pp);
+ u32 mask = PCIE_GLB_STS_RDLH_LINK_UP | PCIE_GLB_STS_PHY_LINK_UP;
+
+ reg = readl(pcie->base + PCIE_GLOBAL_STATUS_REG);
+
+ if ((reg & mask) == mask)
+ return 1;
+
+ pr_debug("No link detected (Global-Status: 0x%08x).\n", reg);
+ return 0;
+}
+
+static void armada8k_pcie_host_init(struct pcie_port *pp)
+{
+ struct armada8k_pcie *pcie = to_armada8k_pcie(pp);
+ void __iomem *base = pcie->base;
+ int timeout = 1000;
+ u32 reg;
+
+ if (!armada8k_pcie_link_up(pp)) {
+ /* Disable LTSSM state machine to enable configuration */
+ reg = readl(base + PCIE_GLOBAL_CONTROL_REG);
+ reg &= ~(PCIE_APP_LTSSM_EN);
+ writel(reg, base + PCIE_GLOBAL_CONTROL_REG);
+ }
+
+ /* Set the device to root complex mode */
+ reg = readl(base + PCIE_GLOBAL_CONTROL_REG);
+ reg &= ~(PCIE_DEVICE_TYPE_MASK << PCIE_DEVICE_TYPE_SHIFT);
+ reg |= PCIE_DEVICE_TYPE_RC << PCIE_DEVICE_TYPE_SHIFT;
+ writel(reg, base + PCIE_GLOBAL_CONTROL_REG);
+
+ /* Set the PCIe master AxCache attributes */
+ writel(ARCACHE_DEFAULT_VALUE, base + PCIE_ARCACHE_TRC_REG);
+ writel(AWCACHE_DEFAULT_VALUE, base + PCIE_AWCACHE_TRC_REG);
+
+ /* Set the PCIe master AxDomain attributes */
+ reg = readl(base + PCIE_ARUSER_REG);
+ reg &= ~(AX_USER_DOMAIN_MASK << AX_USER_DOMAIN_SHIFT);
+ reg |= DOMAIN_OUTER_SHAREABLE << AX_USER_DOMAIN_SHIFT;
+ writel(reg, base + PCIE_ARUSER_REG);
+
+ reg = readl(base + PCIE_AWUSER_REG);
+ reg &= ~(AX_USER_DOMAIN_MASK << AX_USER_DOMAIN_SHIFT);
+ reg |= DOMAIN_OUTER_SHAREABLE << AX_USER_DOMAIN_SHIFT;
+ writel(reg, base + PCIE_AWUSER_REG);
+
+ dw_pcie_setup_rc(pp);
+
+ /* Enable INT A-D interrupts */
+ reg = readl(base + PCIE_GLOBAL_INT_MASK1_REG);
+ reg |= PCIE_INT_A_ASSERT_MASK | PCIE_INT_B_ASSERT_MASK |
+ PCIE_INT_C_ASSERT_MASK | PCIE_INT_D_ASSERT_MASK;
+ writel(reg, base + PCIE_GLOBAL_INT_MASK1_REG);
+
+ if (!armada8k_pcie_link_up(pp)) {
+ /* Configuration done. Start LTSSM */
+ reg = readl(base + PCIE_GLOBAL_CONTROL_REG);
+ reg |= PCIE_APP_LTSSM_EN;
+ writel(reg, base + PCIE_GLOBAL_CONTROL_REG);
+ }
+
+ /* Wait until the link becomes active again */
+ while (timeout) {
+ if (armada8k_pcie_link_up(pp))
+ break;
+ msleep(1);
+ timeout--;
+ }
+
+ if (timeout == 0)
+ dev_err(pp->dev, "Link not up after reconfiguration\n");
+}
+
+static irqreturn_t armada8k_pcie_irq_handler(int irq, void *arg)
+{
+ struct pcie_port *pp = arg;
+ struct armada8k_pcie *pcie = to_armada8k_pcie(pp);
+ void __iomem *base = pcie->base;
+ u32 val;
+
+ /*
+ * Interrupts are directly handled by the device driver of the
+ * PCI device. However, there are also latched into the PCIe
+ * controller, so we simply discard them.
+ */
+ val = readl(base + PCIE_GLOBAL_INT_CAUSE1_REG);
+ writel(val, base + PCIE_GLOBAL_INT_CAUSE1_REG);
+
+ return IRQ_HANDLED;
+}
+
+static struct pcie_host_ops armada8k_pcie_host_ops = {
+ .link_up = armada8k_pcie_link_up,
+ .host_init = armada8k_pcie_host_init,
+};
+
+static int armada8k_pcie_probe(struct platform_device *pdev)
+{
+ struct armada8k_pcie *pcie;
+ struct pcie_port *pp;
+ struct device *dev = &pdev->dev;
+ struct resource *base;
+ int ret;
+
+ pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+ if (!pcie)
+ return -ENOMEM;
+
+ pcie->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(pcie->clk))
+ return PTR_ERR(pcie->clk);
+
+ clk_prepare_enable(pcie->clk);
+
+ pp = &pcie->pp;
+
+ platform_set_drvdata(pdev, pcie);
+
+ /* Get the dw-pcie unit configuration/control registers base. */
+ base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctrl");
+ pp->dbi_base = devm_ioremap_resource(dev, base);
+ if (IS_ERR(pp->dbi_base)) {
+ dev_err(dev, "couldn't remap regs base %p\n", base);
+ ret = PTR_ERR(pp->dbi_base);
+ goto fail;
+ }
+
+ pcie->base = pp->dbi_base + PCIE_VENDOR_REGS_OFFSET;
+
+ pp->dev = dev;
+ pp->root_bus_nr = -1;
+ pp->ops = &armada8k_pcie_host_ops;
+
+ pp->irq = platform_get_irq(pdev, 0);
+ if (!pp->irq) {
+ dev_err(dev, "failed to get irq for port\n");
+ ret = -ENODEV;
+ goto fail;
+ }
+
+ ret = devm_request_irq(dev, pp->irq, armada8k_pcie_irq_handler,
+ IRQF_SHARED, "armada8k-pcie", pp);
+ if (ret) {
+ dev_err(dev, "failed to request irq %d\n", pp->irq);
+ goto fail;
+ }
+
+ ret = dw_pcie_host_init(pp);
+ if (ret) {
+ dev_err(dev, "failed to initialize host: %d\n", ret);
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ if (!IS_ERR(pcie->clk))
+ clk_disable_unprepare(pcie->clk);
+
+ return ret;
+}
+
+static const struct of_device_id armada8k_pcie_of_match[] = {
+ { .compatible = "marvell,armada8k-pcie", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, armada8k_pcie_of_match);
+
+static struct platform_driver armada8k_pcie_driver = {
+ .probe = armada8k_pcie_probe,
+ .driver = {
+ .name = "armada8k-pcie",
+ .of_match_table = of_match_ptr(armada8k_pcie_of_match),
+ },
+};
+
+module_platform_driver(armada8k_pcie_driver);
+
+MODULE_DESCRIPTION("Armada 8k PCIe host controller driver");
+MODULE_AUTHOR("Yehuda Yitshak <yehuday@marvell.com>");
+MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
+MODULE_LICENSE("GPL v2");
--
2.6.4