linux/drivers/pci/host/pcie-armada8k.c

259 lines
6.7 KiB
C

/*
* PCIe host controller driver for Marvell Armada-8K SoCs
*
* Armada-8K PCIe Glue Layer Source Code
*
* Copyright (C) 2016 Marvell Technology Group Ltd.
*
* Author: Yehuda Yitshak <yehuday@marvell.com>
* Author: Shadi Ammouri <shadi@marvell.com>
*
* 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.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/init.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_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)
{
struct armada8k_pcie *pcie = to_armada8k_pcie(pp);
u32 reg;
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;
dev_dbg(pp->dev, "No link detected (Global-Status: 0x%08x).\n", reg);
return 0;
}
static void armada8k_pcie_establish_link(struct pcie_port *pp)
{
struct armada8k_pcie *pcie = to_armada8k_pcie(pp);
void __iomem *base = pcie->base;
u32 reg;
if (!dw_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);
/* 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 (!dw_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 */
if (dw_pcie_wait_for_link(pp))
dev_err(pp->dev, "Link not up after reconfiguration\n");
}
static void armada8k_pcie_host_init(struct pcie_port *pp)
{
dw_pcie_setup_rc(pp);
armada8k_pcie_establish_link(pp);
}
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, they 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_add_pcie_port(struct pcie_port *pp,
struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
int ret;
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");
return -ENODEV;
}
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);
return ret;
}
ret = dw_pcie_host_init(pp);
if (ret) {
dev_err(dev, "failed to initialize host: %d\n", ret);
return ret;
}
return 0;
}
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;
pp->dev = dev;
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;
ret = armada8k_add_pcie_port(pp, pdev);
if (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", },
{},
};
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),
},
};
builtin_platform_driver(armada8k_pcie_driver);