u-boot/drivers/pci/pcie_dw_sifive.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* SiFive FU740 DesignWare PCIe Controller
*
* Copyright (C) 2020-2021 SiFive, Inc.
*
* Based in early part on the i.MX6 PCIe host controller shim which is:
*
* Copyright (C) 2013 Kosagi
* http://www.kosagi.com
*
* Based on driver from author: Alan Mikhak <amikhak@wirelessfabric.com>
*/
#include <asm/io.h>
#include <asm-generic/gpio.h>
#include <clk.h>
#include <common.h>
#include <dm.h>
#include <dm/device_compat.h>
#include <generic-phy.h>
#include <linux/bitops.h>
#include <linux/log2.h>
#include <pci.h>
#include <pci_ep.h>
#include <pci_ids.h>
#include <regmap.h>
#include <reset.h>
#include <syscon.h>
#include "pcie_dw_common.h"
struct pcie_sifive {
/* Must be first member of the struct */
struct pcie_dw dw;
/* private control regs */
void __iomem *priv_base;
/* reset, power, clock resources */
int sys_int_pin;
struct gpio_desc pwren_gpio;
struct gpio_desc reset_gpio;
struct clk aux_ck;
struct reset_ctl reset;
};
enum pcie_sifive_devtype {
SV_PCIE_UNKNOWN_TYPE = 0,
SV_PCIE_ENDPOINT_TYPE = 1,
SV_PCIE_HOST_TYPE = 3
};
#define ASSERTION_DELAY 100
#define PCIE_PERST_ASSERT 0x0
#define PCIE_PERST_DEASSERT 0x1
#define PCIE_PHY_RESET 0x1
#define PCIE_PHY_RESET_DEASSERT 0x0
#define GPIO_LOW 0x0
#define GPIO_HIGH 0x1
#define PCIE_PHY_SEL 0x1
#define sv_info(sv, fmt, arg...) printf(fmt, ## arg)
#define sv_warn(sv, fmt, arg...) printf(fmt, ## arg)
#define sv_debug(sv, fmt, arg...) debug(fmt, ## arg)
#define sv_err(sv, fmt, arg...) printf(fmt, ## arg)
/* Doorbell Interface */
#define DBI_OFFSET 0x0
#define DBI_SIZE 0x1000
#define PL_OFFSET 0x700
#define PHY_DEBUG_R0 (PL_OFFSET + 0x28)
#define PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
#define PHY_DEBUG_R1_LINK_UP (0x1 << 4)
#define PHY_DEBUG_R1_LINK_IN_TRAINING (0x1 << 29)
#define PCIE_MISC_CONTROL_1 0x8bc
#define DBI_RO_WR_EN BIT(0)
/* pcie reset */
#define PCIEX8MGMT_PERST_N 0x0
/* LTSSM */
#define PCIEX8MGMT_APP_LTSSM_ENABLE 0x10
#define LTSSM_ENABLE_BIT BIT(0)
/* phy reset */
#define PCIEX8MGMT_APP_HOLD_PHY_RST 0x18
/* device type */
#define PCIEX8MGMT_DEVICE_TYPE 0x708
#define DEVICE_TYPE_EP 0x0
#define DEVICE_TYPE_RC 0x4
/* phy control registers*/
#define PCIEX8MGMT_PHY0_CR_PARA_ADDR 0x860
#define PCIEX8MGMT_PHY0_CR_PARA_RD_EN 0x870
#define PCIEX8MGMT_PHY0_CR_PARA_RD_DATA 0x878
#define PCIEX8MGMT_PHY0_CR_PARA_SEL 0x880
#define PCIEX8MGMT_PHY0_CR_PARA_WR_DATA 0x888
#define PCIEX8MGMT_PHY0_CR_PARA_WR_EN 0x890
#define PCIEX8MGMT_PHY0_CR_PARA_ACK 0x898
#define PCIEX8MGMT_PHY1_CR_PARA_ADDR 0x8a0
#define PCIEX8MGMT_PHY1_CR_PARA_RD_EN 0x8b0
#define PCIEX8MGMT_PHY1_CR_PARA_RD_DATA 0x8b8
#define PCIEX8MGMT_PHY1_CR_PARA_SEL 0x8c0
#define PCIEX8MGMT_PHY1_CR_PARA_WR_DATA 0x8c8
#define PCIEX8MGMT_PHY1_CR_PARA_WR_EN 0x8d0
#define PCIEX8MGMT_PHY1_CR_PARA_ACK 0x8d8
#define PCIEX8MGMT_LANE_NUM 8
#define PCIEX8MGMT_LANE 0x1008
#define PCIEX8MGMT_LANE_OFF 0x100
#define PCIEX8MGMT_TERM_MODE 0x0e21
#define PCIE_CAP_BASE 0x70
#define PCI_CONFIG(r) (DBI_OFFSET + (r))
#define PCIE_CAPABILITIES(r) PCI_CONFIG(PCIE_CAP_BASE + (r))
/* Link capability */
#define PF0_PCIE_CAP_LINK_CAP PCIE_CAPABILITIES(0xc)
#define PCIE_LINK_CAP_MAX_SPEED_MASK 0xf
#define PCIE_LINK_CAP_MAX_SPEED_GEN1 BIT(0)
#define PCIE_LINK_CAP_MAX_SPEED_GEN2 BIT(1)
#define PCIE_LINK_CAP_MAX_SPEED_GEN3 BIT(2)
#define PCIE_LINK_CAP_MAX_SPEED_GEN4 BIT(3)
static enum pcie_sifive_devtype pcie_sifive_get_devtype(struct pcie_sifive *sv)
{
u32 val;
val = readl(sv->priv_base + PCIEX8MGMT_DEVICE_TYPE);
switch (val) {
case DEVICE_TYPE_RC:
return SV_PCIE_HOST_TYPE;
case DEVICE_TYPE_EP:
return SV_PCIE_ENDPOINT_TYPE;
default:
return SV_PCIE_UNKNOWN_TYPE;
}
}
static void pcie_sifive_priv_set_state(struct pcie_sifive *sv, u32 reg,
u32 bits, int state)
{
u32 val;
val = readl(sv->priv_base + reg);
val = state ? (val | bits) : (val & !bits);
writel(val, sv->priv_base + reg);
}
static void pcie_sifive_assert_reset(struct pcie_sifive *sv)
{
dm_gpio_set_value(&sv->reset_gpio, GPIO_LOW);
writel(PCIE_PERST_ASSERT, sv->priv_base + PCIEX8MGMT_PERST_N);
mdelay(ASSERTION_DELAY);
}
static void pcie_sifive_power_on(struct pcie_sifive *sv)
{
dm_gpio_set_value(&sv->pwren_gpio, GPIO_HIGH);
mdelay(ASSERTION_DELAY);
}
static void pcie_sifive_deassert_reset(struct pcie_sifive *sv)
{
writel(PCIE_PERST_DEASSERT, sv->priv_base + PCIEX8MGMT_PERST_N);
dm_gpio_set_value(&sv->reset_gpio, GPIO_HIGH);
mdelay(ASSERTION_DELAY);
}
static int pcie_sifive_setphy(const u8 phy, const u8 write,
const u16 addr, const u16 wrdata,
u16 *rddata, struct pcie_sifive *sv)
{
unsigned char ack = 0;
if (!(phy == 0 || phy == 1))
return -2;
/* setup phy para */
writel(addr, sv->priv_base +
(phy ? PCIEX8MGMT_PHY1_CR_PARA_ADDR :
PCIEX8MGMT_PHY0_CR_PARA_ADDR));
if (write)
writel(wrdata, sv->priv_base +
(phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_DATA :
PCIEX8MGMT_PHY0_CR_PARA_WR_DATA));
/* enable access if write */
if (write)
writel(1, sv->priv_base +
(phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_EN :
PCIEX8MGMT_PHY0_CR_PARA_WR_EN));
else
writel(1, sv->priv_base +
(phy ? PCIEX8MGMT_PHY1_CR_PARA_RD_EN :
PCIEX8MGMT_PHY0_CR_PARA_RD_EN));
/* wait for wait_idle */
do {
u32 val;
val = readl(sv->priv_base +
(phy ? PCIEX8MGMT_PHY1_CR_PARA_ACK :
PCIEX8MGMT_PHY0_CR_PARA_ACK));
if (val) {
ack = 1;
if (!write)
readl(sv->priv_base +
(phy ? PCIEX8MGMT_PHY1_CR_PARA_RD_DATA :
PCIEX8MGMT_PHY0_CR_PARA_RD_DATA));
mdelay(1);
}
} while (!ack);
/* clear */
if (write)
writel(0, sv->priv_base +
(phy ? PCIEX8MGMT_PHY1_CR_PARA_WR_EN :
PCIEX8MGMT_PHY0_CR_PARA_WR_EN));
else
writel(0, sv->priv_base +
(phy ? PCIEX8MGMT_PHY1_CR_PARA_RD_EN :
PCIEX8MGMT_PHY0_CR_PARA_RD_EN));
while (readl(sv->priv_base +
(phy ? PCIEX8MGMT_PHY1_CR_PARA_ACK :
PCIEX8MGMT_PHY0_CR_PARA_ACK))) {
/* wait for ~wait_idle */
}
return 0;
}
static void pcie_sifive_init_phy(struct pcie_sifive *sv)
{
int lane;
/* enable phy cr_para_sel interfaces */
writel(PCIE_PHY_SEL, sv->priv_base + PCIEX8MGMT_PHY0_CR_PARA_SEL);
writel(PCIE_PHY_SEL, sv->priv_base + PCIEX8MGMT_PHY1_CR_PARA_SEL);
mdelay(1);
/* set PHY AC termination mode */
for (lane = 0; lane < PCIEX8MGMT_LANE_NUM; lane++) {
pcie_sifive_setphy(0, 1,
PCIEX8MGMT_LANE +
(PCIEX8MGMT_LANE_OFF * lane),
PCIEX8MGMT_TERM_MODE, NULL, sv);
pcie_sifive_setphy(1, 1,
PCIEX8MGMT_LANE +
(PCIEX8MGMT_LANE_OFF * lane),
PCIEX8MGMT_TERM_MODE, NULL, sv);
}
}
static int pcie_sifive_check_link(struct pcie_sifive *sv)
{
u32 val;
val = readl(sv->dw.dbi_base + PHY_DEBUG_R1);
return (val & PHY_DEBUG_R1_LINK_UP) &&
!(val & PHY_DEBUG_R1_LINK_IN_TRAINING);
}
static void pcie_sifive_force_gen1(struct pcie_sifive *sv)
{
u32 val, linkcap;
/*
* Force Gen1 operation when starting the link. In case the link is
* started in Gen2 mode, there is a possibility the devices on the
* bus will not be detected at all. This happens with PCIe switches.
*/
/* ctrl_ro_wr_enable */
val = readl(sv->dw.dbi_base + PCIE_MISC_CONTROL_1);
val |= DBI_RO_WR_EN;
writel(val, sv->dw.dbi_base + PCIE_MISC_CONTROL_1);
/* configure link cap */
linkcap = readl(sv->dw.dbi_base + PF0_PCIE_CAP_LINK_CAP);
linkcap |= PCIE_LINK_CAP_MAX_SPEED_MASK;
writel(linkcap, sv->dw.dbi_base + PF0_PCIE_CAP_LINK_CAP);
/* ctrl_ro_wr_disable */
val &= ~DBI_RO_WR_EN;
writel(val, sv->dw.dbi_base + PCIE_MISC_CONTROL_1);
}
static void pcie_sifive_print_phy_debug(struct pcie_sifive *sv)
{
sv_err(sv, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n",
readl(sv->dw.dbi_base + PHY_DEBUG_R0),
readl(sv->dw.dbi_base + PHY_DEBUG_R1));
}
static int pcie_sifive_wait_for_link(struct pcie_sifive *sv)
{
u32 val;
int timeout;
/* Wait for the link to train */
mdelay(20);
timeout = 20;
do {
mdelay(1);
} while (--timeout && !pcie_sifive_check_link(sv));
val = readl(sv->dw.dbi_base + PHY_DEBUG_R1);
if (!(val & PHY_DEBUG_R1_LINK_UP) ||
(val & PHY_DEBUG_R1_LINK_IN_TRAINING)) {
sv_info(sv, "Failed to negotiate PCIe link!\n");
pcie_sifive_print_phy_debug(sv);
writel(PCIE_PHY_RESET,
sv->priv_base + PCIEX8MGMT_APP_HOLD_PHY_RST);
return -ETIMEDOUT;
}
return 0;
}
static int pcie_sifive_start_link(struct pcie_sifive *sv)
{
if (pcie_sifive_check_link(sv))
return -EALREADY;
pcie_sifive_force_gen1(sv);
/* set ltssm */
pcie_sifive_priv_set_state(sv, PCIEX8MGMT_APP_LTSSM_ENABLE,
LTSSM_ENABLE_BIT, 1);
return 0;
}
static int pcie_sifive_init_port(struct udevice *dev,
enum pcie_sifive_devtype mode)
{
struct pcie_sifive *sv = dev_get_priv(dev);
int ret;
/* Power on reset */
pcie_sifive_assert_reset(sv);
pcie_sifive_power_on(sv);
pcie_sifive_deassert_reset(sv);
/* Enable pcieauxclk */
ret = clk_enable(&sv->aux_ck);
if (ret)
dev_err(dev, "unable to enable pcie_aux clock\n");
/*
* assert hold_phy_rst (hold the controller LTSSM in reset
* after power_up_rst_n for register programming with cr_para)
*/
writel(PCIE_PHY_RESET, sv->priv_base + PCIEX8MGMT_APP_HOLD_PHY_RST);
/* deassert power_up_rst_n */
ret = reset_deassert(&sv->reset);
if (ret < 0) {
dev_err(dev, "failed to deassert reset");
return -EINVAL;
}
pcie_sifive_init_phy(sv);
/* disable pcieauxclk */
clk_disable(&sv->aux_ck);
/* deassert hold_phy_rst */
writel(PCIE_PHY_RESET_DEASSERT,
sv->priv_base + PCIEX8MGMT_APP_HOLD_PHY_RST);
/* enable pcieauxclk */
clk_enable(&sv->aux_ck);
/* Set desired mode while core is not operational */
if (mode == SV_PCIE_HOST_TYPE)
writel(DEVICE_TYPE_RC,
sv->priv_base + PCIEX8MGMT_DEVICE_TYPE);
else
writel(DEVICE_TYPE_EP,
sv->priv_base + PCIEX8MGMT_DEVICE_TYPE);
/* Confirm desired mode from operational core */
if (pcie_sifive_get_devtype(sv) != mode)
return -EINVAL;
pcie_dw_setup_host(&sv->dw);
if (pcie_sifive_start_link(sv) == -EALREADY)
sv_info(sv, "PCIe link is already up\n");
else if (pcie_sifive_wait_for_link(sv) == -ETIMEDOUT)
return -ETIMEDOUT;
return 0;
}
static int pcie_sifive_probe(struct udevice *dev)
{
struct pcie_sifive *sv = dev_get_priv(dev);
struct udevice *parent = pci_get_controller(dev);
struct pci_controller *hose = dev_get_uclass_priv(parent);
int err;
sv->dw.first_busno = dev_seq(dev);
sv->dw.dev = dev;
err = pcie_sifive_init_port(dev, SV_PCIE_HOST_TYPE);
if (err) {
sv_info(sv, "Failed to init port.\n");
return err;
}
printf("PCIE-%d: Link up (Gen%d-x%d, Bus%d)\n",
dev_seq(dev), pcie_dw_get_link_speed(&sv->dw),
pcie_dw_get_link_width(&sv->dw),
hose->first_busno);
return pcie_dw_prog_outbound_atu_unroll(&sv->dw,
PCIE_ATU_REGION_INDEX0,
PCIE_ATU_TYPE_MEM,
sv->dw.mem.phys_start,
sv->dw.mem.bus_start,
sv->dw.mem.size);
}
static void __iomem *get_fdt_addr(struct udevice *dev, const char *name)
{
fdt_addr_t addr;
addr = dev_read_addr_name(dev, name);
return (addr == FDT_ADDR_T_NONE) ? NULL : (void __iomem *)addr;
}
static int pcie_sifive_of_to_plat(struct udevice *dev)
{
struct pcie_sifive *sv = dev_get_priv(dev);
int err;
/* get designware DBI base addr */
sv->dw.dbi_base = get_fdt_addr(dev, "dbi");
if (!sv->dw.dbi_base)
return -EINVAL;
/* get private control base addr */
sv->priv_base = get_fdt_addr(dev, "mgmt");
if (!sv->priv_base)
return -EINVAL;
gpio_request_by_name(dev, "pwren-gpios", 0, &sv->pwren_gpio,
GPIOD_IS_OUT);
if (!dm_gpio_is_valid(&sv->pwren_gpio)) {
sv_info(sv, "pwren_gpio is invalid\n");
return -EINVAL;
}
gpio_request_by_name(dev, "reset-gpios", 0, &sv->reset_gpio,
GPIOD_IS_OUT);
if (!dm_gpio_is_valid(&sv->reset_gpio)) {
sv_info(sv, "reset_gpio is invalid\n");
return -EINVAL;
}
err = clk_get_by_index(dev, 0, &sv->aux_ck);
if (err) {
sv_info(sv, "clk_get_by_index(aux_ck) failed: %d\n", err);
return err;
}
err = reset_get_by_index(dev, 0, &sv->reset);
if (err) {
sv_info(sv, "reset_get_by_index(reset) failed: %d\n", err);
return err;
}
return 0;
}
static const struct dm_pci_ops pcie_sifive_ops = {
.read_config = pcie_dw_read_config,
.write_config = pcie_dw_write_config,
};
static const struct udevice_id pcie_sifive_ids[] = {
{ .compatible = "sifive,fu740-pcie" },
{}
};
U_BOOT_DRIVER(pcie_sifive) = {
.name = "pcie_sifive",
.id = UCLASS_PCI,
.of_match = pcie_sifive_ids,
.ops = &pcie_sifive_ops,
.of_to_plat = pcie_sifive_of_to_plat,
.probe = pcie_sifive_probe,
.priv_auto = sizeof(struct pcie_sifive),
};