u-boot/drivers/pci/pcie_imx.c
Stefano Babic a32b4a03c7 pcie_imx: increment timeout for link up
On some boards, the current 20ms timeout
is hit. Increase it to 40mS.

Signed-off-by: Stefano Babic <sbabic@denx.de>
2016-07-12 17:58:48 +02:00

660 lines
17 KiB
C

/*
* Freescale i.MX6 PCI Express Root-Complex driver
*
* Copyright (C) 2013 Marek Vasut <marex@denx.de>
*
* Based on upstream Linux kernel driver:
* pci-imx6.c: Sean Cross <xobs@kosagi.com>
* pcie-designware.c: Jingoo Han <jg1.han@samsung.com>
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <common.h>
#include <pci.h>
#include <asm/arch/clock.h>
#include <asm/arch/iomux.h>
#include <asm/arch/crm_regs.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <linux/sizes.h>
#include <errno.h>
#include <asm/arch/sys_proto.h>
#define PCI_ACCESS_READ 0
#define PCI_ACCESS_WRITE 1
#ifdef CONFIG_MX6SX
#define MX6_DBI_ADDR 0x08ffc000
#define MX6_IO_ADDR 0x08000000
#define MX6_MEM_ADDR 0x08100000
#define MX6_ROOT_ADDR 0x08f00000
#else
#define MX6_DBI_ADDR 0x01ffc000
#define MX6_IO_ADDR 0x01000000
#define MX6_MEM_ADDR 0x01100000
#define MX6_ROOT_ADDR 0x01f00000
#endif
#define MX6_DBI_SIZE 0x4000
#define MX6_IO_SIZE 0x100000
#define MX6_MEM_SIZE 0xe00000
#define MX6_ROOT_SIZE 0xfc000
/* PCIe Port Logic registers (memory-mapped) */
#define PL_OFFSET 0x700
#define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
#define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
#define PCIE_PHY_DEBUG_R1_LINK_UP (1 << 4)
#define PCIE_PHY_DEBUG_R1_LINK_IN_TRAINING (1 << 29)
#define PCIE_PHY_CTRL (PL_OFFSET + 0x114)
#define PCIE_PHY_CTRL_DATA_LOC 0
#define PCIE_PHY_CTRL_CAP_ADR_LOC 16
#define PCIE_PHY_CTRL_CAP_DAT_LOC 17
#define PCIE_PHY_CTRL_WR_LOC 18
#define PCIE_PHY_CTRL_RD_LOC 19
#define PCIE_PHY_STAT (PL_OFFSET + 0x110)
#define PCIE_PHY_STAT_DATA_LOC 0
#define PCIE_PHY_STAT_ACK_LOC 16
/* PHY registers (not memory-mapped) */
#define PCIE_PHY_RX_ASIC_OUT 0x100D
#define PHY_RX_OVRD_IN_LO 0x1005
#define PHY_RX_OVRD_IN_LO_RX_DATA_EN (1 << 5)
#define PHY_RX_OVRD_IN_LO_RX_PLL_EN (1 << 3)
#define PCIE_PHY_PUP_REQ (1 << 7)
/* iATU registers */
#define PCIE_ATU_VIEWPORT 0x900
#define PCIE_ATU_REGION_INBOUND (0x1 << 31)
#define PCIE_ATU_REGION_OUTBOUND (0x0 << 31)
#define PCIE_ATU_REGION_INDEX1 (0x1 << 0)
#define PCIE_ATU_REGION_INDEX0 (0x0 << 0)
#define PCIE_ATU_CR1 0x904
#define PCIE_ATU_TYPE_MEM (0x0 << 0)
#define PCIE_ATU_TYPE_IO (0x2 << 0)
#define PCIE_ATU_TYPE_CFG0 (0x4 << 0)
#define PCIE_ATU_TYPE_CFG1 (0x5 << 0)
#define PCIE_ATU_CR2 0x908
#define PCIE_ATU_ENABLE (0x1 << 31)
#define PCIE_ATU_BAR_MODE_ENABLE (0x1 << 30)
#define PCIE_ATU_LOWER_BASE 0x90C
#define PCIE_ATU_UPPER_BASE 0x910
#define PCIE_ATU_LIMIT 0x914
#define PCIE_ATU_LOWER_TARGET 0x918
#define PCIE_ATU_BUS(x) (((x) & 0xff) << 24)
#define PCIE_ATU_DEV(x) (((x) & 0x1f) << 19)
#define PCIE_ATU_FUNC(x) (((x) & 0x7) << 16)
#define PCIE_ATU_UPPER_TARGET 0x91C
/*
* PHY access functions
*/
static int pcie_phy_poll_ack(void __iomem *dbi_base, int exp_val)
{
u32 val;
u32 max_iterations = 10;
u32 wait_counter = 0;
do {
val = readl(dbi_base + PCIE_PHY_STAT);
val = (val >> PCIE_PHY_STAT_ACK_LOC) & 0x1;
wait_counter++;
if (val == exp_val)
return 0;
udelay(1);
} while (wait_counter < max_iterations);
return -ETIMEDOUT;
}
static int pcie_phy_wait_ack(void __iomem *dbi_base, int addr)
{
u32 val;
int ret;
val = addr << PCIE_PHY_CTRL_DATA_LOC;
writel(val, dbi_base + PCIE_PHY_CTRL);
val |= (0x1 << PCIE_PHY_CTRL_CAP_ADR_LOC);
writel(val, dbi_base + PCIE_PHY_CTRL);
ret = pcie_phy_poll_ack(dbi_base, 1);
if (ret)
return ret;
val = addr << PCIE_PHY_CTRL_DATA_LOC;
writel(val, dbi_base + PCIE_PHY_CTRL);
ret = pcie_phy_poll_ack(dbi_base, 0);
if (ret)
return ret;
return 0;
}
/* Read from the 16-bit PCIe PHY control registers (not memory-mapped) */
static int pcie_phy_read(void __iomem *dbi_base, int addr , int *data)
{
u32 val, phy_ctl;
int ret;
ret = pcie_phy_wait_ack(dbi_base, addr);
if (ret)
return ret;
/* assert Read signal */
phy_ctl = 0x1 << PCIE_PHY_CTRL_RD_LOC;
writel(phy_ctl, dbi_base + PCIE_PHY_CTRL);
ret = pcie_phy_poll_ack(dbi_base, 1);
if (ret)
return ret;
val = readl(dbi_base + PCIE_PHY_STAT);
*data = val & 0xffff;
/* deassert Read signal */
writel(0x00, dbi_base + PCIE_PHY_CTRL);
ret = pcie_phy_poll_ack(dbi_base, 0);
if (ret)
return ret;
return 0;
}
static int pcie_phy_write(void __iomem *dbi_base, int addr, int data)
{
u32 var;
int ret;
/* write addr */
/* cap addr */
ret = pcie_phy_wait_ack(dbi_base, addr);
if (ret)
return ret;
var = data << PCIE_PHY_CTRL_DATA_LOC;
writel(var, dbi_base + PCIE_PHY_CTRL);
/* capture data */
var |= (0x1 << PCIE_PHY_CTRL_CAP_DAT_LOC);
writel(var, dbi_base + PCIE_PHY_CTRL);
ret = pcie_phy_poll_ack(dbi_base, 1);
if (ret)
return ret;
/* deassert cap data */
var = data << PCIE_PHY_CTRL_DATA_LOC;
writel(var, dbi_base + PCIE_PHY_CTRL);
/* wait for ack de-assertion */
ret = pcie_phy_poll_ack(dbi_base, 0);
if (ret)
return ret;
/* assert wr signal */
var = 0x1 << PCIE_PHY_CTRL_WR_LOC;
writel(var, dbi_base + PCIE_PHY_CTRL);
/* wait for ack */
ret = pcie_phy_poll_ack(dbi_base, 1);
if (ret)
return ret;
/* deassert wr signal */
var = data << PCIE_PHY_CTRL_DATA_LOC;
writel(var, dbi_base + PCIE_PHY_CTRL);
/* wait for ack de-assertion */
ret = pcie_phy_poll_ack(dbi_base, 0);
if (ret)
return ret;
writel(0x0, dbi_base + PCIE_PHY_CTRL);
return 0;
}
static int imx6_pcie_link_up(void)
{
u32 rc, ltssm;
int rx_valid, temp;
/* link is debug bit 36, debug register 1 starts at bit 32 */
rc = readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R1);
if ((rc & PCIE_PHY_DEBUG_R1_LINK_UP) &&
!(rc & PCIE_PHY_DEBUG_R1_LINK_IN_TRAINING))
return -EAGAIN;
/*
* From L0, initiate MAC entry to gen2 if EP/RC supports gen2.
* Wait 2ms (LTSSM timeout is 24ms, PHY lock is ~5us in gen2).
* If (MAC/LTSSM.state == Recovery.RcvrLock)
* && (PHY/rx_valid==0) then pulse PHY/rx_reset. Transition
* to gen2 is stuck
*/
pcie_phy_read((void *)MX6_DBI_ADDR, PCIE_PHY_RX_ASIC_OUT, &rx_valid);
ltssm = readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R0) & 0x3F;
if (rx_valid & 0x01)
return 0;
if (ltssm != 0x0d)
return 0;
printf("transition to gen2 is stuck, reset PHY!\n");
pcie_phy_read((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, &temp);
temp |= (PHY_RX_OVRD_IN_LO_RX_DATA_EN | PHY_RX_OVRD_IN_LO_RX_PLL_EN);
pcie_phy_write((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, temp);
udelay(3000);
pcie_phy_read((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, &temp);
temp &= ~(PHY_RX_OVRD_IN_LO_RX_DATA_EN | PHY_RX_OVRD_IN_LO_RX_PLL_EN);
pcie_phy_write((void *)MX6_DBI_ADDR, PHY_RX_OVRD_IN_LO, temp);
return 0;
}
/*
* iATU region setup
*/
static int imx_pcie_regions_setup(void)
{
/*
* i.MX6 defines 16MB in the AXI address map for PCIe.
*
* That address space excepted the pcie registers is
* split and defined into different regions by iATU,
* with sizes and offsets as follows:
*
* 0x0100_0000 --- 0x010F_FFFF 1MB IORESOURCE_IO
* 0x0110_0000 --- 0x01EF_FFFF 14MB IORESOURCE_MEM
* 0x01F0_0000 --- 0x01FF_FFFF 1MB Cfg + Registers
*/
/* CMD reg:I/O space, MEM space, and Bus Master Enable */
setbits_le32(MX6_DBI_ADDR | PCI_COMMAND,
PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
/* Set the CLASS_REV of RC CFG header to PCI_CLASS_BRIDGE_PCI */
setbits_le32(MX6_DBI_ADDR + PCI_CLASS_REVISION,
PCI_CLASS_BRIDGE_PCI << 16);
/* Region #0 is used for Outbound CFG space access. */
writel(0, MX6_DBI_ADDR + PCIE_ATU_VIEWPORT);
writel(MX6_ROOT_ADDR, MX6_DBI_ADDR + PCIE_ATU_LOWER_BASE);
writel(0, MX6_DBI_ADDR + PCIE_ATU_UPPER_BASE);
writel(MX6_ROOT_ADDR + MX6_ROOT_SIZE, MX6_DBI_ADDR + PCIE_ATU_LIMIT);
writel(0, MX6_DBI_ADDR + PCIE_ATU_LOWER_TARGET);
writel(0, MX6_DBI_ADDR + PCIE_ATU_UPPER_TARGET);
writel(PCIE_ATU_TYPE_CFG0, MX6_DBI_ADDR + PCIE_ATU_CR1);
writel(PCIE_ATU_ENABLE, MX6_DBI_ADDR + PCIE_ATU_CR2);
return 0;
}
/*
* PCI Express accessors
*/
static uint32_t get_bus_address(pci_dev_t d, int where)
{
uint32_t va_address;
/* Reconfigure Region #0 */
writel(0, MX6_DBI_ADDR + PCIE_ATU_VIEWPORT);
if (PCI_BUS(d) < 2)
writel(PCIE_ATU_TYPE_CFG0, MX6_DBI_ADDR + PCIE_ATU_CR1);
else
writel(PCIE_ATU_TYPE_CFG1, MX6_DBI_ADDR + PCIE_ATU_CR1);
if (PCI_BUS(d) == 0) {
va_address = MX6_DBI_ADDR;
} else {
writel(d << 8, MX6_DBI_ADDR + PCIE_ATU_LOWER_TARGET);
va_address = MX6_IO_ADDR + SZ_16M - SZ_1M;
}
va_address += (where & ~0x3);
return va_address;
}
static int imx_pcie_addr_valid(pci_dev_t d)
{
if ((PCI_BUS(d) == 0) && (PCI_DEV(d) > 1))
return -EINVAL;
if ((PCI_BUS(d) == 1) && (PCI_DEV(d) > 0))
return -EINVAL;
return 0;
}
/*
* Replace the original ARM DABT handler with a simple jump-back one.
*
* The problem here is that if we have a PCIe bridge attached to this PCIe
* controller, but no PCIe device is connected to the bridges' downstream
* port, the attempt to read/write from/to the config space will produce
* a DABT. This is a behavior of the controller and can not be disabled
* unfortuatelly.
*
* To work around the problem, we backup the current DABT handler address
* and replace it with our own DABT handler, which only bounces right back
* into the code.
*/
static void imx_pcie_fix_dabt_handler(bool set)
{
extern uint32_t *_data_abort;
uint32_t *data_abort_addr = (uint32_t *)&_data_abort;
static const uint32_t data_abort_bounce_handler = 0xe25ef004;
uint32_t data_abort_bounce_addr = (uint32_t)&data_abort_bounce_handler;
static uint32_t data_abort_backup;
if (set) {
data_abort_backup = *data_abort_addr;
*data_abort_addr = data_abort_bounce_addr;
} else {
*data_abort_addr = data_abort_backup;
}
}
static int imx_pcie_read_config(struct pci_controller *hose, pci_dev_t d,
int where, u32 *val)
{
uint32_t va_address;
int ret;
ret = imx_pcie_addr_valid(d);
if (ret) {
*val = 0xffffffff;
return 0;
}
va_address = get_bus_address(d, where);
/*
* Read the PCIe config space. We must replace the DABT handler
* here in case we got data abort from the PCIe controller, see
* imx_pcie_fix_dabt_handler() description. Note that writing the
* "val" with valid value is also imperative here as in case we
* did got DABT, the val would contain random value.
*/
imx_pcie_fix_dabt_handler(true);
writel(0xffffffff, val);
*val = readl(va_address);
imx_pcie_fix_dabt_handler(false);
return 0;
}
static int imx_pcie_write_config(struct pci_controller *hose, pci_dev_t d,
int where, u32 val)
{
uint32_t va_address = 0;
int ret;
ret = imx_pcie_addr_valid(d);
if (ret)
return ret;
va_address = get_bus_address(d, where);
/*
* Write the PCIe config space. We must replace the DABT handler
* here in case we got data abort from the PCIe controller, see
* imx_pcie_fix_dabt_handler() description.
*/
imx_pcie_fix_dabt_handler(true);
writel(val, va_address);
imx_pcie_fix_dabt_handler(false);
return 0;
}
/*
* Initial bus setup
*/
static int imx6_pcie_assert_core_reset(void)
{
struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR;
if (is_mx6dqp())
setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_PCIE_SW_RST);
#if defined(CONFIG_MX6SX)
struct gpc *gpc_regs = (struct gpc *)GPC_BASE_ADDR;
/* SSP_EN is not used on MX6SX anymore */
setbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_TEST_POWERDOWN);
/* Force PCIe PHY reset */
setbits_le32(&iomuxc_regs->gpr[5], IOMUXC_GPR5_PCIE_BTNRST);
/* Power up PCIe PHY */
setbits_le32(&gpc_regs->cntr, PCIE_PHY_PUP_REQ);
#else
setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_TEST_POWERDOWN);
clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_REF_SSP_EN);
#endif
return 0;
}
static int imx6_pcie_init_phy(void)
{
struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR;
clrbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_APPS_LTSSM_ENABLE);
clrsetbits_le32(&iomuxc_regs->gpr[12],
IOMUXC_GPR12_DEVICE_TYPE_MASK,
IOMUXC_GPR12_DEVICE_TYPE_RC);
clrsetbits_le32(&iomuxc_regs->gpr[12],
IOMUXC_GPR12_LOS_LEVEL_MASK,
IOMUXC_GPR12_LOS_LEVEL_9);
#ifdef CONFIG_MX6SX
clrsetbits_le32(&iomuxc_regs->gpr[12],
IOMUXC_GPR12_RX_EQ_MASK,
IOMUXC_GPR12_RX_EQ_2);
#endif
writel((0x0 << IOMUXC_GPR8_PCS_TX_DEEMPH_GEN1_OFFSET) |
(0x0 << IOMUXC_GPR8_PCS_TX_DEEMPH_GEN2_3P5DB_OFFSET) |
(20 << IOMUXC_GPR8_PCS_TX_DEEMPH_GEN2_6DB_OFFSET) |
(127 << IOMUXC_GPR8_PCS_TX_SWING_FULL_OFFSET) |
(127 << IOMUXC_GPR8_PCS_TX_SWING_LOW_OFFSET),
&iomuxc_regs->gpr[8]);
return 0;
}
__weak int imx6_pcie_toggle_power(void)
{
#ifdef CONFIG_PCIE_IMX_POWER_GPIO
gpio_direction_output(CONFIG_PCIE_IMX_POWER_GPIO, 0);
mdelay(20);
gpio_set_value(CONFIG_PCIE_IMX_POWER_GPIO, 1);
mdelay(20);
#endif
return 0;
}
__weak int imx6_pcie_toggle_reset(void)
{
/*
* See 'PCI EXPRESS BASE SPECIFICATION, REV 3.0, SECTION 6.6.1'
* for detailed understanding of the PCIe CR reset logic.
*
* The PCIe #PERST reset line _MUST_ be connected, otherwise your
* design does not conform to the specification. You must wait at
* least 20 ms after de-asserting the #PERST so the EP device can
* do self-initialisation.
*
* In case your #PERST pin is connected to a plain GPIO pin of the
* CPU, you can define CONFIG_PCIE_IMX_PERST_GPIO in your board's
* configuration file and the condition below will handle the rest
* of the reset toggling.
*
* In case your #PERST toggling logic is more complex, for example
* connected via CPLD or somesuch, you can override this function
* in your board file and implement reset logic as needed. You must
* not forget to wait at least 20 ms after de-asserting #PERST in
* this case either though.
*
* In case your #PERST line of the PCIe EP device is not connected
* at all, your design is broken and you should fix your design,
* otherwise you will observe problems like for example the link
* not coming up after rebooting the system back from running Linux
* that uses the PCIe as well OR the PCIe link might not come up in
* Linux at all in the first place since it's in some non-reset
* state due to being previously used in U-Boot.
*/
#ifdef CONFIG_PCIE_IMX_PERST_GPIO
gpio_direction_output(CONFIG_PCIE_IMX_PERST_GPIO, 0);
mdelay(20);
gpio_set_value(CONFIG_PCIE_IMX_PERST_GPIO, 1);
mdelay(20);
#else
puts("WARNING: Make sure the PCIe #PERST line is connected!\n");
#endif
return 0;
}
static int imx6_pcie_deassert_core_reset(void)
{
struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR;
imx6_pcie_toggle_power();
enable_pcie_clock();
if (is_mx6dqp())
clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_PCIE_SW_RST);
/*
* Wait for the clock to settle a bit, when the clock are sourced
* from the CPU, we need about 30 ms to settle.
*/
mdelay(50);
#if defined(CONFIG_MX6SX)
/* SSP_EN is not used on MX6SX anymore */
clrbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_TEST_POWERDOWN);
/* Clear PCIe PHY reset bit */
clrbits_le32(&iomuxc_regs->gpr[5], IOMUXC_GPR5_PCIE_BTNRST);
#else
/* Enable PCIe */
clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_TEST_POWERDOWN);
setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_REF_SSP_EN);
#endif
imx6_pcie_toggle_reset();
return 0;
}
static int imx_pcie_link_up(void)
{
struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR;
uint32_t tmp;
int count = 0;
imx6_pcie_assert_core_reset();
imx6_pcie_init_phy();
imx6_pcie_deassert_core_reset();
imx_pcie_regions_setup();
/*
* FIXME: Force the PCIe RC to Gen1 operation
* The RC must be forced into Gen1 mode before bringing the link
* up, otherwise no downstream devices are detected. After the
* link is up, a managed Gen1->Gen2 transition can be initiated.
*/
tmp = readl(MX6_DBI_ADDR + 0x7c);
tmp &= ~0xf;
tmp |= 0x1;
writel(tmp, MX6_DBI_ADDR + 0x7c);
/* LTSSM enable, starting link. */
setbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_APPS_LTSSM_ENABLE);
while (!imx6_pcie_link_up()) {
udelay(10);
count++;
if (count >= 4000) {
#ifdef CONFIG_PCI_SCAN_SHOW
puts("PCI: pcie phy link never came up\n");
#endif
debug("DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n",
readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R0),
readl(MX6_DBI_ADDR + PCIE_PHY_DEBUG_R1));
return -EINVAL;
}
}
return 0;
}
void imx_pcie_init(void)
{
/* Static instance of the controller. */
static struct pci_controller pcc;
struct pci_controller *hose = &pcc;
int ret;
memset(&pcc, 0, sizeof(pcc));
/* PCI I/O space */
pci_set_region(&hose->regions[0],
MX6_IO_ADDR, MX6_IO_ADDR,
MX6_IO_SIZE, PCI_REGION_IO);
/* PCI memory space */
pci_set_region(&hose->regions[1],
MX6_MEM_ADDR, MX6_MEM_ADDR,
MX6_MEM_SIZE, PCI_REGION_MEM);
/* System memory space */
pci_set_region(&hose->regions[2],
MMDC0_ARB_BASE_ADDR, MMDC0_ARB_BASE_ADDR,
0xefffffff, PCI_REGION_MEM | PCI_REGION_SYS_MEMORY);
hose->region_count = 3;
pci_set_ops(hose,
pci_hose_read_config_byte_via_dword,
pci_hose_read_config_word_via_dword,
imx_pcie_read_config,
pci_hose_write_config_byte_via_dword,
pci_hose_write_config_word_via_dword,
imx_pcie_write_config);
/* Start the controller. */
ret = imx_pcie_link_up();
if (!ret) {
pci_register_hose(hose);
hose->last_busno = pci_hose_scan(hose);
}
}
/* Probe function. */
void pci_init_board(void)
{
imx_pcie_init();
}