linux_dsm_epyc7002/drivers/pci/host/pci-layerscape.c
Bjorn Helgaas e3dc17a53f PCI: layerscape: Simplify platform_get_resource_byname() failure checking
devm_ioremap_resource() validates the resource it receives, so if we check
for devm_ioremap_resource() failure, we need not check for failure of the
preceding platform_get_resource().

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-04-09 14:36:52 -05:00

176 lines
3.9 KiB
C

/*
* PCIe host controller driver for Freescale Layerscape SoCs
*
* Copyright (C) 2014 Freescale Semiconductor.
*
* Author: Minghuan Lian <Minghuan.Lian@freescale.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/resource.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include "pcie-designware.h"
/* PEX1/2 Misc Ports Status Register */
#define SCFG_PEXMSCPORTSR(pex_idx) (0x94 + (pex_idx) * 4)
#define LTSSM_STATE_SHIFT 20
#define LTSSM_STATE_MASK 0x3f
#define LTSSM_PCIE_L0 0x11 /* L0 state */
/* Symbol Timer Register and Filter Mask Register 1 */
#define PCIE_STRFMR1 0x71c
struct ls_pcie {
struct list_head node;
struct device *dev;
struct pci_bus *bus;
void __iomem *dbi;
struct regmap *scfg;
struct pcie_port pp;
int index;
int msi_irq;
};
#define to_ls_pcie(x) container_of(x, struct ls_pcie, pp)
static int ls_pcie_link_up(struct pcie_port *pp)
{
u32 state;
struct ls_pcie *pcie = to_ls_pcie(pp);
regmap_read(pcie->scfg, SCFG_PEXMSCPORTSR(pcie->index), &state);
state = (state >> LTSSM_STATE_SHIFT) & LTSSM_STATE_MASK;
if (state < LTSSM_PCIE_L0)
return 0;
return 1;
}
static void ls_pcie_host_init(struct pcie_port *pp)
{
struct ls_pcie *pcie = to_ls_pcie(pp);
int count = 0;
u32 val;
dw_pcie_setup_rc(pp);
while (!ls_pcie_link_up(pp)) {
usleep_range(100, 1000);
count++;
if (count >= 200) {
dev_err(pp->dev, "phy link never came up\n");
return;
}
}
/*
* LS1021A Workaround for internal TKT228622
* to fix the INTx hang issue
*/
val = ioread32(pcie->dbi + PCIE_STRFMR1);
val &= 0xffff;
iowrite32(val, pcie->dbi + PCIE_STRFMR1);
}
static struct pcie_host_ops ls_pcie_host_ops = {
.link_up = ls_pcie_link_up,
.host_init = ls_pcie_host_init,
};
static int ls_add_pcie_port(struct ls_pcie *pcie)
{
struct pcie_port *pp;
int ret;
pp = &pcie->pp;
pp->dev = pcie->dev;
pp->dbi_base = pcie->dbi;
pp->root_bus_nr = -1;
pp->ops = &ls_pcie_host_ops;
ret = dw_pcie_host_init(pp);
if (ret) {
dev_err(pp->dev, "failed to initialize host\n");
return ret;
}
return 0;
}
static int __init ls_pcie_probe(struct platform_device *pdev)
{
struct ls_pcie *pcie;
struct resource *dbi_base;
u32 index[2];
int ret;
pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
if (!pcie)
return -ENOMEM;
pcie->dev = &pdev->dev;
dbi_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
pcie->dbi = devm_ioremap_resource(&pdev->dev, dbi_base);
if (IS_ERR(pcie->dbi)) {
dev_err(&pdev->dev, "missing *regs* space\n");
return PTR_ERR(pcie->dbi);
}
pcie->scfg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
"fsl,pcie-scfg");
if (IS_ERR(pcie->scfg)) {
dev_err(&pdev->dev, "No syscfg phandle specified\n");
return PTR_ERR(pcie->scfg);
}
ret = of_property_read_u32_array(pdev->dev.of_node,
"fsl,pcie-scfg", index, 2);
if (ret)
return ret;
pcie->index = index[1];
ret = ls_add_pcie_port(pcie);
if (ret < 0)
return ret;
platform_set_drvdata(pdev, pcie);
return 0;
}
static const struct of_device_id ls_pcie_of_match[] = {
{ .compatible = "fsl,ls1021a-pcie" },
{ },
};
MODULE_DEVICE_TABLE(of, ls_pcie_of_match);
static struct platform_driver ls_pcie_driver = {
.driver = {
.name = "layerscape-pcie",
.of_match_table = ls_pcie_of_match,
},
};
module_platform_driver_probe(ls_pcie_driver, ls_pcie_probe);
MODULE_AUTHOR("Minghuan Lian <Minghuan.Lian@freescale.com>");
MODULE_DESCRIPTION("Freescale Layerscape PCIe host controller driver");
MODULE_LICENSE("GPL v2");