openwrt/target/linux/oxnas/files/drivers/pci/host/pcie-oxnas.c
Daniel Golle e7aa4c0db7 oxnas: pcie: model shared resource as external pcie-phy driver
Refactor pcie-oxnas to have shared resources in syscon and new pcie-phy
driver. Hopefully this revives PCIe...

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2019-03-04 23:40:43 +01:00

656 lines
17 KiB
C

/*
* PCIe driver for PLX NAS782X SoCs
*
* Author: Ma Haijun <mahaijuns@gmail.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/kernel.h>
#include <linux/pci.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/mbus.h>
#include <linux/mfd/syscon.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/phy.h>
#include <linux/phy/phy.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/io.h>
#include <linux/sizes.h>
#define SYS_CTRL_HCSL_CTRL_REGOFFSET 0x114
static inline void oxnas_register_clear_mask(void __iomem *p, unsigned mask)
{
u32 val = readl_relaxed(p);
val &= ~mask;
writel_relaxed(val, p);
}
static inline void oxnas_register_set_mask(void __iomem *p, unsigned mask)
{
u32 val = readl_relaxed(p);
val |= mask;
writel_relaxed(val, p);
}
static inline void oxnas_register_value_mask(void __iomem *p,
unsigned mask, unsigned new_value)
{
/* TODO sanity check mask & new_value = new_value */
u32 val = readl_relaxed(p);
val &= ~mask;
val |= new_value;
writel_relaxed(val, p);
}
#define VERSION_ID_MAGIC 0x082510b5
#define LINK_UP_TIMEOUT_SECONDS 1
#define NUM_CONTROLLERS 1
enum {
PCIE_DEVICE_TYPE_MASK = 0x0F,
PCIE_DEVICE_TYPE_ENDPOINT = 0,
PCIE_DEVICE_TYPE_LEGACY_ENDPOINT = 1,
PCIE_DEVICE_TYPE_ROOT = 4,
PCIE_LTSSM = BIT(4),
PCIE_READY_ENTR_L23 = BIT(9),
PCIE_LINK_UP = BIT(11),
PCIE_OBTRANS = BIT(12),
};
/* core config registers */
enum {
PCI_CONFIG_VERSION_DEVICEID = 0,
PCI_CONFIG_COMMAND_STATUS = 4,
};
/* inbound config registers */
enum {
IB_ADDR_XLATE_ENABLE = 0xFC,
/* bits */
ENABLE_IN_ADDR_TRANS = BIT(0),
};
/* outbound config registers, offset relative to PCIE_POM0_MEM_ADDR */
enum {
PCIE_POM0_MEM_ADDR = 0,
PCIE_POM1_MEM_ADDR = 4,
PCIE_IN0_MEM_ADDR = 8,
PCIE_IN1_MEM_ADDR = 12,
PCIE_IN_IO_ADDR = 16,
PCIE_IN_CFG0_ADDR = 20,
PCIE_IN_CFG1_ADDR = 24,
PCIE_IN_MSG_ADDR = 28,
PCIE_IN0_MEM_LIMIT = 32,
PCIE_IN1_MEM_LIMIT = 36,
PCIE_IN_IO_LIMIT = 40,
PCIE_IN_CFG0_LIMIT = 44,
PCIE_IN_CFG1_LIMIT = 48,
PCIE_IN_MSG_LIMIT = 52,
PCIE_AHB_SLAVE_CTRL = 56,
PCIE_SLAVE_BE_SHIFT = 22,
};
#define PCIE_SLAVE_BE(val) ((val) << PCIE_SLAVE_BE_SHIFT)
#define PCIE_SLAVE_BE_MASK PCIE_SLAVE_BE(0xF)
struct oxnas_pcie_shared {
/* seems all access are serialized, no lock required */
int refcount;
};
/* Structure representing one PCIe interfaces */
struct oxnas_pcie {
void __iomem *cfgbase;
void __iomem *base;
void __iomem *inbound;
struct regmap *sys_ctrl;
unsigned int outbound_offset;
unsigned int pcie_ctrl_offset;
struct phy *phy;
int haslink;
struct platform_device *pdev;
struct resource io;
struct resource cfg;
struct resource pre_mem; /* prefetchable */
struct resource non_mem; /* non-prefetchable */
struct resource busn; /* max available bus numbers */
int card_reset; /* gpio pin, optional */
unsigned hcsl_en; /* hcsl pci enable bit */
struct clk *clk;
struct clk *busclk; /* for pcie bus, actually the PLLB */
void *private_data[1];
spinlock_t lock;
};
static struct oxnas_pcie_shared pcie_shared = {
.refcount = 0,
};
static inline struct oxnas_pcie *sys_to_pcie(struct pci_sys_data *sys)
{
return sys->private_data;
}
static inline void set_out_lanes(struct oxnas_pcie *pcie, unsigned lanes)
{
regmap_update_bits(pcie->sys_ctrl, pcie->outbound_offset + PCIE_AHB_SLAVE_CTRL,
PCIE_SLAVE_BE_MASK, PCIE_SLAVE_BE(lanes));
wmb();
}
static int oxnas_pcie_link_up(struct oxnas_pcie *pcie)
{
unsigned long end;
unsigned int val;
/* Poll for PCIE link up */
end = jiffies + (LINK_UP_TIMEOUT_SECONDS * HZ);
while (!time_after(jiffies, end)) {
regmap_read(pcie->sys_ctrl, pcie->pcie_ctrl_offset, &val);
if (val & PCIE_LINK_UP)
return 1;
}
return 0;
}
static void oxnas_pcie_setup_hw(struct oxnas_pcie *pcie)
{
/* We won't have any inbound address translation. This allows PCI
* devices to access anywhere in the AHB address map. Might be regarded
* as a bit dangerous, but let's get things working before we worry
* about that
*/
oxnas_register_clear_mask(pcie->inbound + IB_ADDR_XLATE_ENABLE,
ENABLE_IN_ADDR_TRANS);
wmb();
/*
* Program outbound translation windows
*
* Outbound window is what is referred to as "PCI client" region in HRM
*
* Could use the larger alternative address space to get >>64M regions
* for graphics cards etc., but will not bother at this point.
*
* IP bug means that AMBA window size must be a power of 2
*
* Set mem0 window for first 16MB of outbound window non-prefetchable
* Set mem1 window for second 16MB of outbound window prefetchable
* Set io window for next 16MB of outbound window
* Set cfg0 for final 1MB of outbound window
*
* Ignore mem1, cfg1 and msg windows for now as no obvious use cases for
* 820 that would need them
*
* Probably ideally want no offset between mem0 window start as seen by
* ARM and as seen on PCI bus and get Linux to assign memory regions to
* PCI devices using the same "PCI client" region start address as seen
* by ARM
*/
/* Set PCIeA mem0 region to be 1st 16MB of the 64MB PCIeA window */
regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN0_MEM_ADDR, pcie->non_mem.start);
regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN0_MEM_LIMIT, pcie->non_mem.end);
regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_POM0_MEM_ADDR, pcie->non_mem.start);
/* Set PCIeA mem1 region to be 2nd 16MB of the 64MB PCIeA window */
regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN1_MEM_ADDR, pcie->pre_mem.start);
regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN1_MEM_LIMIT, pcie->pre_mem.end);
regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_POM1_MEM_ADDR, pcie->pre_mem.start);
/* Set PCIeA io to be third 16M region of the 64MB PCIeA window*/
regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_IO_ADDR, pcie->io.start);
regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_IO_LIMIT, pcie->io.end);
/* Set PCIeA cgf0 to be last 16M region of the 64MB PCIeA window*/
regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_CFG0_ADDR, pcie->cfg.start);
regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_CFG0_LIMIT, pcie->cfg.end);
wmb();
/* Enable outbound address translation */
regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset, PCIE_OBTRANS, PCIE_OBTRANS);
wmb();
/*
* Program PCIe command register for core to:
* enable memory space
* enable bus master
* enable io
*/
writel_relaxed(7, pcie->base + PCI_CONFIG_COMMAND_STATUS);
/* which is which */
wmb();
}
static unsigned oxnas_pcie_cfg_to_offset(
struct pci_sys_data *sys,
unsigned char bus_number,
unsigned int devfn,
int where)
{
unsigned int function = PCI_FUNC(devfn);
unsigned int slot = PCI_SLOT(devfn);
unsigned char bus_number_offset;
bus_number_offset = bus_number - sys->busnr;
/*
* We'll assume for now that the offset, function, slot, bus encoding
* should map onto linear, contiguous addresses in PCIe config space,
* albeit that the majority will be unused as only slot 0 is valid for
* any PCIe bus and most devices have only function 0
*
* Could be that PCIe in fact works by not encoding the slot number into
* the config space address as it's known that only slot 0 is valid.
* We'll have to experiment if/when we get a PCIe switch connected to
* the PCIe host
*/
return (bus_number_offset << 20) | (slot << 15) | (function << 12) |
(where & ~3);
}
/* PCI configuration space write function */
static int oxnas_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
int where, int size, u32 val)
{
unsigned long flags;
struct oxnas_pcie *pcie = sys_to_pcie(bus->sysdata);
unsigned offset;
u32 value;
u32 lanes;
/* Only a single device per bus for PCIe point-to-point links */
if (PCI_SLOT(devfn) > 0)
return PCIBIOS_DEVICE_NOT_FOUND;
if (!pcie->haslink)
return PCIBIOS_DEVICE_NOT_FOUND;
offset = oxnas_pcie_cfg_to_offset(bus->sysdata, bus->number, devfn,
where);
value = val << (8 * (where & 3));
lanes = (0xf >> (4-size)) << (where & 3);
/* it race with mem and io write, but the possibility is low, normally
* all config writes happens at driver initialize stage, wont interleave
* with others.
* and many pcie cards use dword (4bytes) access mem/io access only,
* so not bother to copy that ugly work-around now. */
spin_lock_irqsave(&pcie->lock, flags);
set_out_lanes(pcie, lanes);
writel_relaxed(value, pcie->cfgbase + offset);
set_out_lanes(pcie, 0xf);
spin_unlock_irqrestore(&pcie->lock, flags);
return PCIBIOS_SUCCESSFUL;
}
/* PCI configuration space read function */
static int oxnas_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
int size, u32 *val)
{
struct oxnas_pcie *pcie = sys_to_pcie(bus->sysdata);
unsigned offset;
u32 value;
u32 left_bytes, right_bytes;
/* Only a single device per bus for PCIe point-to-point links */
if (PCI_SLOT(devfn) > 0) {
*val = 0xffffffff;
return PCIBIOS_DEVICE_NOT_FOUND;
}
if (!pcie->haslink) {
*val = 0xffffffff;
return PCIBIOS_DEVICE_NOT_FOUND;
}
offset = oxnas_pcie_cfg_to_offset(bus->sysdata, bus->number, devfn,
where);
value = readl_relaxed(pcie->cfgbase + offset);
left_bytes = where & 3;
right_bytes = 4 - left_bytes - size;
value <<= right_bytes * 8;
value >>= (left_bytes + right_bytes) * 8;
*val = value;
return PCIBIOS_SUCCESSFUL;
}
static struct pci_ops oxnas_pcie_ops = {
.read = oxnas_pcie_rd_conf,
.write = oxnas_pcie_wr_conf,
};
static int oxnas_pcie_setup(int nr, struct pci_sys_data *sys)
{
struct oxnas_pcie *pcie = sys_to_pcie(sys);
pci_add_resource_offset(&sys->resources, &pcie->non_mem, sys->mem_offset);
pci_add_resource_offset(&sys->resources, &pcie->pre_mem, sys->mem_offset);
pci_add_resource_offset(&sys->resources, &pcie->io, sys->io_offset);
pci_add_resource(&sys->resources, &pcie->busn);
if (sys->busnr == 0) { /* default one */
sys->busnr = pcie->busn.start;
}
/* do not use devm_ioremap_resource, it does not like cfg resource */
pcie->cfgbase = devm_ioremap(&pcie->pdev->dev, pcie->cfg.start,
resource_size(&pcie->cfg));
if (!pcie->cfgbase)
return -ENOMEM;
oxnas_pcie_setup_hw(pcie);
return 1;
}
static void oxnas_pcie_enable(struct device *dev, struct oxnas_pcie *pcie)
{
struct hw_pci hw;
int i;
memset(&hw, 0, sizeof(hw));
for (i = 0; i < NUM_CONTROLLERS; i++)
pcie->private_data[i] = pcie;
hw.nr_controllers = NUM_CONTROLLERS;
/* I think use stack pointer is a bad idea though it is valid in this case */
hw.private_data = pcie->private_data;
hw.setup = oxnas_pcie_setup;
hw.map_irq = of_irq_parse_and_map_pci;
hw.ops = &oxnas_pcie_ops;
/* pass dev to maintain of tree, interrupt mapping rely on this */
pci_common_init_dev(dev, &hw);
}
static int oxnas_pcie_shared_init(struct platform_device *pdev, struct oxnas_pcie *pcie)
{
if (++pcie_shared.refcount == 1) {
phy_init(pcie->phy);
phy_power_on(pcie->phy);
return 0;
} else {
return 0;
}
}
#if 0
/* maybe we will call it when enter low power state */
static void oxnas_pcie_shared_deinit(struct platform_device *pdev)
{
if (--pcie_shared.refcount == 0) {
/* no cleanup needed */;
}
}
#endif
static int
oxnas_pcie_map_registers(struct platform_device *pdev,
struct device_node *np,
struct oxnas_pcie *pcie)
{
struct resource regs;
int ret = 0;
u32 outbound_ctrl_offset;
u32 pcie_ctrl_offset;
ret = of_address_to_resource(np, 0, &regs);
if (ret)
return -EINVAL;
pcie->base = devm_ioremap_resource(&pdev->dev, &regs);
if (!pcie->base)
return -ENOMEM;
ret = of_address_to_resource(np, 1, &regs);
if (ret)
return -EINVAL;
pcie->inbound = devm_ioremap_resource(&pdev->dev, &regs);
if (!pcie->inbound)
return -ENOMEM;
pcie->phy = devm_of_phy_get(&pdev->dev, np, NULL);
if (IS_ERR(pcie->phy)) {
if (PTR_ERR(pcie->phy) == -EPROBE_DEFER)
return PTR_ERR(pcie->phy);
pcie->phy = NULL;
}
if (of_property_read_u32(np, "plxtech,pcie-outbound-offset",
&outbound_ctrl_offset))
return -EINVAL;
pcie->outbound_offset = outbound_ctrl_offset;
if (of_property_read_u32(np, "plxtech,pcie-ctrl-offset",
&pcie_ctrl_offset))
return -EINVAL;
pcie->pcie_ctrl_offset = pcie_ctrl_offset;
return 0;
}
static int oxnas_pcie_init_res(struct platform_device *pdev,
struct oxnas_pcie *pcie,
struct device_node *np)
{
struct of_pci_range range;
struct of_pci_range_parser parser;
int ret;
if (of_pci_range_parser_init(&parser, np))
return -EINVAL;
/* Get the I/O and memory ranges from DT */
for_each_of_pci_range(&parser, &range) {
unsigned long restype = range.flags & IORESOURCE_TYPE_BITS;
if (restype == IORESOURCE_IO) {
of_pci_range_to_resource(&range, np, &pcie->io);
pcie->io.name = "I/O";
}
if (restype == IORESOURCE_MEM) {
if (range.flags & IORESOURCE_PREFETCH) {
of_pci_range_to_resource(&range, np, &pcie->pre_mem);
pcie->pre_mem.name = "PRE MEM";
} else {
of_pci_range_to_resource(&range, np, &pcie->non_mem);
pcie->non_mem.name = "NON MEM";
}
}
if (restype == 0)
of_pci_range_to_resource(&range, np, &pcie->cfg);
}
/* Get the bus range */
ret = of_pci_parse_bus_range(np, &pcie->busn);
if (ret) {
dev_err(&pdev->dev, "failed to parse bus-range property: %d\n",
ret);
return ret;
}
pcie->card_reset = of_get_gpio(np, 0);
if (pcie->card_reset < 0)
dev_info(&pdev->dev, "card reset gpio pin not exists\n");
if (of_property_read_u32(np, "plxtech,pcie-hcsl-bit", &pcie->hcsl_en))
return -EINVAL;
pcie->clk = of_clk_get_by_name(np, "pcie");
if (IS_ERR(pcie->clk)) {
return PTR_ERR(pcie->clk);
}
pcie->busclk = of_clk_get_by_name(np, "busclk");
if (IS_ERR(pcie->busclk)) {
clk_put(pcie->clk);
return PTR_ERR(pcie->busclk);
}
return 0;
}
static void oxnas_pcie_init_hw(struct platform_device *pdev,
struct oxnas_pcie *pcie)
{
u32 version_id;
int ret;
clk_prepare_enable(pcie->busclk);
/* reset PCIe cards use hard-wired gpio pin */
if (pcie->card_reset >= 0 &&
!gpio_direction_output(pcie->card_reset, 0)) {
wmb();
mdelay(10);
/* must tri-state the pin to pull it up */
gpio_direction_input(pcie->card_reset);
wmb();
mdelay(100);
}
/* ToDo: use phy power-on port... */
regmap_update_bits(pcie->sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET,
BIT(pcie->hcsl_en), BIT(pcie->hcsl_en));
/* core */
ret = device_reset(&pdev->dev);
if (ret) {
dev_err(&pdev->dev, "core reset failed %d\n", ret);
return;
}
/* Start PCIe core clocks */
clk_prepare_enable(pcie->clk);
version_id = readl_relaxed(pcie->base + PCI_CONFIG_VERSION_DEVICEID);
dev_info(&pdev->dev, "PCIe version/deviceID 0x%x\n", version_id);
if (version_id != VERSION_ID_MAGIC) {
dev_info(&pdev->dev, "PCIe controller not found\n");
pcie->haslink = 0;
return;
}
/* allow entry to L23 state */
regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset,
PCIE_READY_ENTR_L23, PCIE_READY_ENTR_L23);
/* Set PCIe core into RootCore mode */
regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset,
PCIE_DEVICE_TYPE_MASK, PCIE_DEVICE_TYPE_ROOT);
wmb();
/* Bring up the PCI core */
regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset,
PCIE_LTSSM, PCIE_LTSSM);
wmb();
}
static int oxnas_pcie_probe(struct platform_device *pdev)
{
struct oxnas_pcie *pcie;
struct device_node *np = pdev->dev.of_node;
int ret;
pcie = devm_kzalloc(&pdev->dev, sizeof(struct oxnas_pcie),
GFP_KERNEL);
if (!pcie)
return -ENOMEM;
pcie->pdev = pdev;
pcie->haslink = 1;
spin_lock_init(&pcie->lock);
pcie->sys_ctrl = syscon_regmap_lookup_by_compatible("oxsemi,ox820-sys-ctrl");
if (IS_ERR(pcie->sys_ctrl))
return PTR_ERR(pcie->sys_ctrl);
ret = oxnas_pcie_init_res(pdev, pcie, np);
if (ret)
return ret;
if (pcie->card_reset >= 0) {
ret = gpio_request_one(pcie->card_reset, GPIOF_DIR_IN,
dev_name(&pdev->dev));
if (ret) {
dev_err(&pdev->dev, "cannot request gpio pin %d\n",
pcie->card_reset);
return ret;
}
}
ret = oxnas_pcie_map_registers(pdev, np, pcie);
if (ret) {
dev_err(&pdev->dev, "cannot map registers\n");
goto err_free_gpio;
}
ret = oxnas_pcie_shared_init(pdev, pcie);
if (ret)
goto err_free_gpio;
/* if hw not found, haslink cleared */
oxnas_pcie_init_hw(pdev, pcie);
if (pcie->haslink && oxnas_pcie_link_up(pcie)) {
pcie->haslink = 1;
dev_info(&pdev->dev, "link up\n");
} else {
pcie->haslink = 0;
dev_info(&pdev->dev, "link down\n");
}
/* should we register our controller even when pcie->haslink is 0 ? */
/* register the controller with framework */
oxnas_pcie_enable(&pdev->dev, pcie);
return 0;
err_free_gpio:
if (pcie->card_reset)
gpio_free(pcie->card_reset);
return ret;
}
static const struct of_device_id oxnas_pcie_of_match_table[] = {
{ .compatible = "plxtech,nas782x-pcie", },
{},
};
static struct platform_driver oxnas_pcie_driver = {
.driver = {
.name = "oxnas-pcie",
.suppress_bind_attrs = true,
.of_match_table = oxnas_pcie_of_match_table,
},
.probe = oxnas_pcie_probe,
};
builtin_platform_driver(oxnas_pcie_driver);