linux/drivers/pci/host/pcie-iproc.c
Ray Jui 1fb37a8178 PCI: iproc: Add Broadcom iProc PCIe support
Add support for the Broadcom iProc PCIe controller.

pcie-iproc.c is the common core driver, and a front-end bus interface needs
to be added to support different bus interfaces.

pcie-iproc-platform.c contains the support for the platform bus interface.

Signed-off-by: Ray Jui <rjui@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2015-04-08 14:19:36 -05:00

269 lines
6.9 KiB
C

/*
* Copyright (C) 2014 Hauke Mehrtens <hauke@hauke-m.de>
* Copyright (C) 2015 Broadcom Corporatcommon ion
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/mbus.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/phy/phy.h>
#include "pcie-iproc.h"
#define CLK_CONTROL_OFFSET 0x000
#define EP_MODE_SURVIVE_PERST_SHIFT 1
#define EP_MODE_SURVIVE_PERST BIT(EP_MODE_SURVIVE_PERST_SHIFT)
#define RC_PCIE_RST_OUTPUT_SHIFT 0
#define RC_PCIE_RST_OUTPUT BIT(RC_PCIE_RST_OUTPUT_SHIFT)
#define CFG_IND_ADDR_OFFSET 0x120
#define CFG_IND_ADDR_MASK 0x00001ffc
#define CFG_IND_DATA_OFFSET 0x124
#define CFG_ADDR_OFFSET 0x1f8
#define CFG_ADDR_BUS_NUM_SHIFT 20
#define CFG_ADDR_BUS_NUM_MASK 0x0ff00000
#define CFG_ADDR_DEV_NUM_SHIFT 15
#define CFG_ADDR_DEV_NUM_MASK 0x000f8000
#define CFG_ADDR_FUNC_NUM_SHIFT 12
#define CFG_ADDR_FUNC_NUM_MASK 0x00007000
#define CFG_ADDR_REG_NUM_SHIFT 2
#define CFG_ADDR_REG_NUM_MASK 0x00000ffc
#define CFG_ADDR_CFG_TYPE_SHIFT 0
#define CFG_ADDR_CFG_TYPE_MASK 0x00000003
#define CFG_DATA_OFFSET 0x1fc
#define SYS_RC_INTX_EN 0x330
#define SYS_RC_INTX_MASK 0xf
static inline struct iproc_pcie *sys_to_pcie(struct pci_sys_data *sys)
{
return sys->private_data;
}
/**
* Note access to the configuration registers are protected at the higher layer
* by 'pci_lock' in drivers/pci/access.c
*/
static void __iomem *iproc_pcie_map_cfg_bus(struct pci_bus *bus,
unsigned int devfn,
int where)
{
struct pci_sys_data *sys = bus->sysdata;
struct iproc_pcie *pcie = sys_to_pcie(sys);
unsigned slot = PCI_SLOT(devfn);
unsigned fn = PCI_FUNC(devfn);
unsigned busno = bus->number;
u32 val;
/* root complex access */
if (busno == 0) {
if (slot >= 1)
return NULL;
writel(where & CFG_IND_ADDR_MASK,
pcie->base + CFG_IND_ADDR_OFFSET);
return (pcie->base + CFG_IND_DATA_OFFSET);
}
if (fn > 1)
return NULL;
/* EP device access */
val = (busno << CFG_ADDR_BUS_NUM_SHIFT) |
(slot << CFG_ADDR_DEV_NUM_SHIFT) |
(fn << CFG_ADDR_FUNC_NUM_SHIFT) |
(where & CFG_ADDR_REG_NUM_MASK) |
(1 & CFG_ADDR_CFG_TYPE_MASK);
writel(val, pcie->base + CFG_ADDR_OFFSET);
return (pcie->base + CFG_DATA_OFFSET);
}
static struct pci_ops iproc_pcie_ops = {
.map_bus = iproc_pcie_map_cfg_bus,
.read = pci_generic_config_read32,
.write = pci_generic_config_write32,
};
static void iproc_pcie_reset(struct iproc_pcie *pcie)
{
u32 val;
/*
* Configure the PCIe controller as root complex and send a downstream
* reset
*/
val = EP_MODE_SURVIVE_PERST | RC_PCIE_RST_OUTPUT;
writel(val, pcie->base + CLK_CONTROL_OFFSET);
udelay(250);
val &= ~EP_MODE_SURVIVE_PERST;
writel(val, pcie->base + CLK_CONTROL_OFFSET);
msleep(250);
}
static int iproc_pcie_check_link(struct iproc_pcie *pcie, struct pci_bus *bus)
{
u8 hdr_type;
u32 link_ctrl;
u16 pos, link_status;
int link_is_active = 0;
/* make sure we are not in EP mode */
pci_bus_read_config_byte(bus, 0, PCI_HEADER_TYPE, &hdr_type);
if ((hdr_type & 0x7f) != PCI_HEADER_TYPE_BRIDGE) {
dev_err(pcie->dev, "in EP mode, hdr=%#02x\n", hdr_type);
return -EFAULT;
}
/* force class to PCI_CLASS_BRIDGE_PCI (0x0604) */
pci_bus_write_config_word(bus, 0, PCI_CLASS_DEVICE,
PCI_CLASS_BRIDGE_PCI);
/* check link status to see if link is active */
pos = pci_bus_find_capability(bus, 0, PCI_CAP_ID_EXP);
pci_bus_read_config_word(bus, 0, pos + PCI_EXP_LNKSTA, &link_status);
if (link_status & PCI_EXP_LNKSTA_NLW)
link_is_active = 1;
if (!link_is_active) {
/* try GEN 1 link speed */
#define PCI_LINK_STATUS_CTRL_2_OFFSET 0x0dc
#define PCI_TARGET_LINK_SPEED_MASK 0xf
#define PCI_TARGET_LINK_SPEED_GEN2 0x2
#define PCI_TARGET_LINK_SPEED_GEN1 0x1
pci_bus_read_config_dword(bus, 0,
PCI_LINK_STATUS_CTRL_2_OFFSET,
&link_ctrl);
if ((link_ctrl & PCI_TARGET_LINK_SPEED_MASK) ==
PCI_TARGET_LINK_SPEED_GEN2) {
link_ctrl &= ~PCI_TARGET_LINK_SPEED_MASK;
link_ctrl |= PCI_TARGET_LINK_SPEED_GEN1;
pci_bus_write_config_dword(bus, 0,
PCI_LINK_STATUS_CTRL_2_OFFSET,
link_ctrl);
msleep(100);
pos = pci_bus_find_capability(bus, 0, PCI_CAP_ID_EXP);
pci_bus_read_config_word(bus, 0, pos + PCI_EXP_LNKSTA,
&link_status);
if (link_status & PCI_EXP_LNKSTA_NLW)
link_is_active = 1;
}
}
dev_info(pcie->dev, "link: %s\n", link_is_active ? "UP" : "DOWN");
return link_is_active ? 0 : -ENODEV;
}
static void iproc_pcie_enable(struct iproc_pcie *pcie)
{
writel(SYS_RC_INTX_MASK, pcie->base + SYS_RC_INTX_EN);
}
int iproc_pcie_setup(struct iproc_pcie *pcie)
{
int ret;
struct pci_bus *bus;
if (!pcie || !pcie->dev || !pcie->base)
return -EINVAL;
if (pcie->phy) {
ret = phy_init(pcie->phy);
if (ret) {
dev_err(pcie->dev, "unable to initialize PCIe PHY\n");
return ret;
}
ret = phy_power_on(pcie->phy);
if (ret) {
dev_err(pcie->dev, "unable to power on PCIe PHY\n");
goto err_exit_phy;
}
}
iproc_pcie_reset(pcie);
pcie->sysdata.private_data = pcie;
bus = pci_create_root_bus(pcie->dev, 0, &iproc_pcie_ops,
&pcie->sysdata, pcie->resources);
if (!bus) {
dev_err(pcie->dev, "unable to create PCI root bus\n");
ret = -ENOMEM;
goto err_power_off_phy;
}
pcie->root_bus = bus;
ret = iproc_pcie_check_link(pcie, bus);
if (ret) {
dev_err(pcie->dev, "no PCIe EP device detected\n");
goto err_rm_root_bus;
}
iproc_pcie_enable(pcie);
pci_scan_child_bus(bus);
pci_assign_unassigned_bus_resources(bus);
pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
pci_bus_add_devices(bus);
return 0;
err_rm_root_bus:
pci_stop_root_bus(bus);
pci_remove_root_bus(bus);
err_power_off_phy:
if (pcie->phy)
phy_power_off(pcie->phy);
err_exit_phy:
if (pcie->phy)
phy_exit(pcie->phy);
return ret;
}
EXPORT_SYMBOL(iproc_pcie_setup);
int iproc_pcie_remove(struct iproc_pcie *pcie)
{
pci_stop_root_bus(pcie->root_bus);
pci_remove_root_bus(pcie->root_bus);
if (pcie->phy) {
phy_power_off(pcie->phy);
phy_exit(pcie->phy);
}
return 0;
}
EXPORT_SYMBOL(iproc_pcie_remove);
MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
MODULE_DESCRIPTION("Broadcom iPROC PCIe common driver");
MODULE_LICENSE("GPL v2");