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linux/drivers/pci/controller/dwc/pci-imx6.c
Leonard Crestez 9e56f0df36 PCI: imx: Add imx6sx suspend/resume support 
Enable PCI suspend/resume support on imx6sx SOCs. This is similar to
imx7d with a few differences:

* The PM_Turn_Off bit is exposed through an IOMUX GPR, like all other
pcie control bits on 6sx.
* The pcie_inbound_axi clk needs to be turned off in suspend. On resume
it is restored via resume -> deassert_core_reset -> enable_ref_clk.

Most of the resume logic is shared with the initial reset after probe.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
2018-12-18 12:01:16 +00:00

1119 lines
29 KiB
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// SPDX-License-Identifier: GPL-2.0
/*
* PCIe host controller driver for Freescale i.MX6 SoCs
*
* Copyright (C) 2013 Kosagi
* http://www.kosagi.com
*
* Author: Sean Cross <xobs@kosagi.com>
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
#include <linux/mfd/syscon/imx7-iomuxc-gpr.h>
#include <linux/module.h>
#include <linux/of_gpio.h>
#include <linux/of_device.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/resource.h>
#include <linux/signal.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/reset.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include "pcie-designware.h"
#define to_imx6_pcie(x) dev_get_drvdata((x)->dev)
enum imx6_pcie_variants {
IMX6Q,
IMX6SX,
IMX6QP,
IMX7D,
};
struct imx6_pcie {
struct dw_pcie *pci;
int reset_gpio;
bool gpio_active_high;
struct clk *pcie_bus;
struct clk *pcie_phy;
struct clk *pcie_inbound_axi;
struct clk *pcie;
struct regmap *iomuxc_gpr;
struct reset_control *pciephy_reset;
struct reset_control *apps_reset;
struct reset_control *turnoff_reset;
enum imx6_pcie_variants variant;
u32 tx_deemph_gen1;
u32 tx_deemph_gen2_3p5db;
u32 tx_deemph_gen2_6db;
u32 tx_swing_full;
u32 tx_swing_low;
int link_gen;
struct regulator *vpcie;
/* power domain for pcie */
struct device *pd_pcie;
/* power domain for pcie phy */
struct device *pd_pcie_phy;
};
/* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
#define PHY_PLL_LOCK_WAIT_MAX_RETRIES 2000
#define PHY_PLL_LOCK_WAIT_USLEEP_MIN 50
#define PHY_PLL_LOCK_WAIT_USLEEP_MAX 200
/* PCIe Root Complex registers (memory-mapped) */
#define PCIE_RC_LCR 0x7c
#define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1 0x1
#define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2 0x2
#define PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK 0xf
#define PCIE_RC_LCSR 0x80
/* PCIe Port Logic registers (memory-mapped) */
#define PL_OFFSET 0x700
#define PCIE_PL_PFLR (PL_OFFSET + 0x08)
#define PCIE_PL_PFLR_LINK_STATE_MASK (0x3f << 16)
#define PCIE_PL_PFLR_FORCE_LINK (1 << 15)
#define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
#define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
#define PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING (1 << 29)
#define PCIE_PHY_DEBUG_R1_XMLH_LINK_UP (1 << 4)
#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_ACK_LOC 16
#define PCIE_LINK_WIDTH_SPEED_CONTROL 0x80C
#define PORT_LOGIC_SPEED_CHANGE (0x1 << 17)
/* PHY registers (not memory-mapped) */
#define PCIE_PHY_ATEOVRD 0x10
#define PCIE_PHY_ATEOVRD_EN (0x1 << 2)
#define PCIE_PHY_ATEOVRD_REF_CLKDIV_SHIFT 0
#define PCIE_PHY_ATEOVRD_REF_CLKDIV_MASK 0x1
#define PCIE_PHY_MPLL_OVRD_IN_LO 0x11
#define PCIE_PHY_MPLL_MULTIPLIER_SHIFT 2
#define PCIE_PHY_MPLL_MULTIPLIER_MASK 0x7f
#define PCIE_PHY_MPLL_MULTIPLIER_OVRD (0x1 << 9)
#define PCIE_PHY_RX_ASIC_OUT 0x100D
#define PCIE_PHY_RX_ASIC_OUT_VALID (1 << 0)
#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)
static int pcie_phy_poll_ack(struct imx6_pcie *imx6_pcie, int exp_val)
{
struct dw_pcie *pci = imx6_pcie->pci;
u32 val;
u32 max_iterations = 10;
u32 wait_counter = 0;
do {
val = dw_pcie_readl_dbi(pci, 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(struct imx6_pcie *imx6_pcie, int addr)
{
struct dw_pcie *pci = imx6_pcie->pci;
u32 val;
int ret;
val = addr << PCIE_PHY_CTRL_DATA_LOC;
dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
val |= (0x1 << PCIE_PHY_CTRL_CAP_ADR_LOC);
dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
ret = pcie_phy_poll_ack(imx6_pcie, 1);
if (ret)
return ret;
val = addr << PCIE_PHY_CTRL_DATA_LOC;
dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, val);
return pcie_phy_poll_ack(imx6_pcie, 0);
}
/* Read from the 16-bit PCIe PHY control registers (not memory-mapped) */
static int pcie_phy_read(struct imx6_pcie *imx6_pcie, int addr, int *data)
{
struct dw_pcie *pci = imx6_pcie->pci;
u32 val, phy_ctl;
int ret;
ret = pcie_phy_wait_ack(imx6_pcie, addr);
if (ret)
return ret;
/* assert Read signal */
phy_ctl = 0x1 << PCIE_PHY_CTRL_RD_LOC;
dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, phy_ctl);
ret = pcie_phy_poll_ack(imx6_pcie, 1);
if (ret)
return ret;
val = dw_pcie_readl_dbi(pci, PCIE_PHY_STAT);
*data = val & 0xffff;
/* deassert Read signal */
dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, 0x00);
return pcie_phy_poll_ack(imx6_pcie, 0);
}
static int pcie_phy_write(struct imx6_pcie *imx6_pcie, int addr, int data)
{
struct dw_pcie *pci = imx6_pcie->pci;
u32 var;
int ret;
/* write addr */
/* cap addr */
ret = pcie_phy_wait_ack(imx6_pcie, addr);
if (ret)
return ret;
var = data << PCIE_PHY_CTRL_DATA_LOC;
dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
/* capture data */
var |= (0x1 << PCIE_PHY_CTRL_CAP_DAT_LOC);
dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
ret = pcie_phy_poll_ack(imx6_pcie, 1);
if (ret)
return ret;
/* deassert cap data */
var = data << PCIE_PHY_CTRL_DATA_LOC;
dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
/* wait for ack de-assertion */
ret = pcie_phy_poll_ack(imx6_pcie, 0);
if (ret)
return ret;
/* assert wr signal */
var = 0x1 << PCIE_PHY_CTRL_WR_LOC;
dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
/* wait for ack */
ret = pcie_phy_poll_ack(imx6_pcie, 1);
if (ret)
return ret;
/* deassert wr signal */
var = data << PCIE_PHY_CTRL_DATA_LOC;
dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, var);
/* wait for ack de-assertion */
ret = pcie_phy_poll_ack(imx6_pcie, 0);
if (ret)
return ret;
dw_pcie_writel_dbi(pci, PCIE_PHY_CTRL, 0x0);
return 0;
}
static void imx6_pcie_reset_phy(struct imx6_pcie *imx6_pcie)
{
u32 tmp;
pcie_phy_read(imx6_pcie, PHY_RX_OVRD_IN_LO, &tmp);
tmp |= (PHY_RX_OVRD_IN_LO_RX_DATA_EN |
PHY_RX_OVRD_IN_LO_RX_PLL_EN);
pcie_phy_write(imx6_pcie, PHY_RX_OVRD_IN_LO, tmp);
usleep_range(2000, 3000);
pcie_phy_read(imx6_pcie, PHY_RX_OVRD_IN_LO, &tmp);
tmp &= ~(PHY_RX_OVRD_IN_LO_RX_DATA_EN |
PHY_RX_OVRD_IN_LO_RX_PLL_EN);
pcie_phy_write(imx6_pcie, PHY_RX_OVRD_IN_LO, tmp);
}
/* Added for PCI abort handling */
static int imx6q_pcie_abort_handler(unsigned long addr,
unsigned int fsr, struct pt_regs *regs)
{
unsigned long pc = instruction_pointer(regs);
unsigned long instr = *(unsigned long *)pc;
int reg = (instr >> 12) & 15;
/*
* If the instruction being executed was a read,
* make it look like it read all-ones.
*/
if ((instr & 0x0c100000) == 0x04100000) {
unsigned long val;
if (instr & 0x00400000)
val = 255;
else
val = -1;
regs->uregs[reg] = val;
regs->ARM_pc += 4;
return 0;
}
if ((instr & 0x0e100090) == 0x00100090) {
regs->uregs[reg] = -1;
regs->ARM_pc += 4;
return 0;
}
return 1;
}
static int imx6_pcie_attach_pd(struct device *dev)
{
struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
struct device_link *link;
/* Do nothing when in a single power domain */
if (dev->pm_domain)
return 0;
imx6_pcie->pd_pcie = dev_pm_domain_attach_by_name(dev, "pcie");
if (IS_ERR(imx6_pcie->pd_pcie))
return PTR_ERR(imx6_pcie->pd_pcie);
link = device_link_add(dev, imx6_pcie->pd_pcie,
DL_FLAG_STATELESS |
DL_FLAG_PM_RUNTIME |
DL_FLAG_RPM_ACTIVE);
if (!link) {
dev_err(dev, "Failed to add device_link to pcie pd.\n");
return -EINVAL;
}
imx6_pcie->pd_pcie_phy = dev_pm_domain_attach_by_name(dev, "pcie_phy");
if (IS_ERR(imx6_pcie->pd_pcie_phy))
return PTR_ERR(imx6_pcie->pd_pcie_phy);
device_link_add(dev, imx6_pcie->pd_pcie_phy,
DL_FLAG_STATELESS |
DL_FLAG_PM_RUNTIME |
DL_FLAG_RPM_ACTIVE);
if (IS_ERR(link)) {
dev_err(dev, "Failed to add device_link to pcie_phy pd: %ld\n", PTR_ERR(link));
return PTR_ERR(link);
}
return 0;
}
static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
{
struct device *dev = imx6_pcie->pci->dev;
switch (imx6_pcie->variant) {
case IMX7D:
reset_control_assert(imx6_pcie->pciephy_reset);
reset_control_assert(imx6_pcie->apps_reset);
break;
case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
/* Force PCIe PHY reset */
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
IMX6SX_GPR5_PCIE_BTNRST_RESET,
IMX6SX_GPR5_PCIE_BTNRST_RESET);
break;
case IMX6QP:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_SW_RST,
IMX6Q_GPR1_PCIE_SW_RST);
break;
case IMX6Q:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
break;
}
if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
int ret = regulator_disable(imx6_pcie->vpcie);
if (ret)
dev_err(dev, "failed to disable vpcie regulator: %d\n",
ret);
}
}
static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
{
struct dw_pcie *pci = imx6_pcie->pci;
struct device *dev = pci->dev;
int ret = 0;
switch (imx6_pcie->variant) {
case IMX6SX:
ret = clk_prepare_enable(imx6_pcie->pcie_inbound_axi);
if (ret) {
dev_err(dev, "unable to enable pcie_axi clock\n");
break;
}
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0);
break;
case IMX6QP: /* FALLTHROUGH */
case IMX6Q:
/* power up core phy and enable ref clock */
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
/*
* the async reset input need ref clock to sync internally,
* when the ref clock comes after reset, internal synced
* reset time is too short, cannot meet the requirement.
* add one ~10us delay here.
*/
udelay(10);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
break;
case IMX7D:
break;
}
return ret;
}
static void imx7d_pcie_wait_for_phy_pll_lock(struct imx6_pcie *imx6_pcie)
{
u32 val;
unsigned int retries;
struct device *dev = imx6_pcie->pci->dev;
for (retries = 0; retries < PHY_PLL_LOCK_WAIT_MAX_RETRIES; retries++) {
regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR22, &val);
if (val & IMX7D_GPR22_PCIE_PHY_PLL_LOCKED)
return;
usleep_range(PHY_PLL_LOCK_WAIT_USLEEP_MIN,
PHY_PLL_LOCK_WAIT_USLEEP_MAX);
}
dev_err(dev, "PCIe PLL lock timeout\n");
}
static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
{
struct dw_pcie *pci = imx6_pcie->pci;
struct device *dev = pci->dev;
int ret;
if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) {
ret = regulator_enable(imx6_pcie->vpcie);
if (ret) {
dev_err(dev, "failed to enable vpcie regulator: %d\n",
ret);
return;
}
}
ret = clk_prepare_enable(imx6_pcie->pcie_phy);
if (ret) {
dev_err(dev, "unable to enable pcie_phy clock\n");
goto err_pcie_phy;
}
ret = clk_prepare_enable(imx6_pcie->pcie_bus);
if (ret) {
dev_err(dev, "unable to enable pcie_bus clock\n");
goto err_pcie_bus;
}
ret = clk_prepare_enable(imx6_pcie->pcie);
if (ret) {
dev_err(dev, "unable to enable pcie clock\n");
goto err_pcie;
}
ret = imx6_pcie_enable_ref_clk(imx6_pcie);
if (ret) {
dev_err(dev, "unable to enable pcie ref clock\n");
goto err_ref_clk;
}
/* allow the clocks to stabilize */
usleep_range(200, 500);
/* Some boards don't have PCIe reset GPIO. */
if (gpio_is_valid(imx6_pcie->reset_gpio)) {
gpio_set_value_cansleep(imx6_pcie->reset_gpio,
imx6_pcie->gpio_active_high);
msleep(100);
gpio_set_value_cansleep(imx6_pcie->reset_gpio,
!imx6_pcie->gpio_active_high);
}
switch (imx6_pcie->variant) {
case IMX7D:
reset_control_deassert(imx6_pcie->pciephy_reset);
imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie);
break;
case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
break;
case IMX6QP:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_SW_RST, 0);
usleep_range(200, 500);
break;
case IMX6Q: /* Nothing to do */
break;
}
return;
err_ref_clk:
clk_disable_unprepare(imx6_pcie->pcie);
err_pcie:
clk_disable_unprepare(imx6_pcie->pcie_bus);
err_pcie_bus:
clk_disable_unprepare(imx6_pcie->pcie_phy);
err_pcie_phy:
if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
ret = regulator_disable(imx6_pcie->vpcie);
if (ret)
dev_err(dev, "failed to disable vpcie regulator: %d\n",
ret);
}
}
static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
{
switch (imx6_pcie->variant) {
case IMX7D:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
break;
case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_RX_EQ_MASK,
IMX6SX_GPR12_PCIE_RX_EQ_2);
/* FALLTHROUGH */
default:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
/* configure constant input signal to the pcie ctrl and phy */
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
IMX6Q_GPR8_TX_DEEMPH_GEN1,
imx6_pcie->tx_deemph_gen1 << 0);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
imx6_pcie->tx_deemph_gen2_3p5db << 6);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
imx6_pcie->tx_deemph_gen2_6db << 12);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
IMX6Q_GPR8_TX_SWING_FULL,
imx6_pcie->tx_swing_full << 18);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
IMX6Q_GPR8_TX_SWING_LOW,
imx6_pcie->tx_swing_low << 25);
break;
}
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6Q_GPR12_DEVICE_TYPE, PCI_EXP_TYPE_ROOT_PORT << 12);
}
static int imx6_setup_phy_mpll(struct imx6_pcie *imx6_pcie)
{
unsigned long phy_rate = clk_get_rate(imx6_pcie->pcie_phy);
int mult, div;
u32 val;
switch (phy_rate) {
case 125000000:
/*
* The default settings of the MPLL are for a 125MHz input
* clock, so no need to reconfigure anything in that case.
*/
return 0;
case 100000000:
mult = 25;
div = 0;
break;
case 200000000:
mult = 25;
div = 1;
break;
default:
dev_err(imx6_pcie->pci->dev,
"Unsupported PHY reference clock rate %lu\n", phy_rate);
return -EINVAL;
}
pcie_phy_read(imx6_pcie, PCIE_PHY_MPLL_OVRD_IN_LO, &val);
val &= ~(PCIE_PHY_MPLL_MULTIPLIER_MASK <<
PCIE_PHY_MPLL_MULTIPLIER_SHIFT);
val |= mult << PCIE_PHY_MPLL_MULTIPLIER_SHIFT;
val |= PCIE_PHY_MPLL_MULTIPLIER_OVRD;
pcie_phy_write(imx6_pcie, PCIE_PHY_MPLL_OVRD_IN_LO, val);
pcie_phy_read(imx6_pcie, PCIE_PHY_ATEOVRD, &val);
val &= ~(PCIE_PHY_ATEOVRD_REF_CLKDIV_MASK <<
PCIE_PHY_ATEOVRD_REF_CLKDIV_SHIFT);
val |= div << PCIE_PHY_ATEOVRD_REF_CLKDIV_SHIFT;
val |= PCIE_PHY_ATEOVRD_EN;
pcie_phy_write(imx6_pcie, PCIE_PHY_ATEOVRD, val);
return 0;
}
static int imx6_pcie_wait_for_link(struct imx6_pcie *imx6_pcie)
{
struct dw_pcie *pci = imx6_pcie->pci;
struct device *dev = pci->dev;
/* check if the link is up or not */
if (!dw_pcie_wait_for_link(pci))
return 0;
dev_dbg(dev, "DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n",
dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R0),
dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1));
return -ETIMEDOUT;
}
static int imx6_pcie_wait_for_speed_change(struct imx6_pcie *imx6_pcie)
{
struct dw_pcie *pci = imx6_pcie->pci;
struct device *dev = pci->dev;
u32 tmp;
unsigned int retries;
for (retries = 0; retries < 200; retries++) {
tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
/* Test if the speed change finished. */
if (!(tmp & PORT_LOGIC_SPEED_CHANGE))
return 0;
usleep_range(100, 1000);
}
dev_err(dev, "Speed change timeout\n");
return -EINVAL;
}
static void imx6_pcie_ltssm_enable(struct device *dev)
{
struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
switch (imx6_pcie->variant) {
case IMX6Q:
case IMX6SX:
case IMX6QP:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6Q_GPR12_PCIE_CTL_2,
IMX6Q_GPR12_PCIE_CTL_2);
break;
case IMX7D:
reset_control_deassert(imx6_pcie->apps_reset);
break;
}
}
static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
{
struct dw_pcie *pci = imx6_pcie->pci;
struct device *dev = pci->dev;
u32 tmp;
int ret;
/*
* 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.
*/
tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCR);
tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1;
dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
/* Start LTSSM. */
imx6_pcie_ltssm_enable(dev);
ret = imx6_pcie_wait_for_link(imx6_pcie);
if (ret)
goto err_reset_phy;
if (imx6_pcie->link_gen == 2) {
/* Allow Gen2 mode after the link is up. */
tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCR);
tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2;
dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
/*
* Start Directed Speed Change so the best possible
* speed both link partners support can be negotiated.
*/
tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
tmp |= PORT_LOGIC_SPEED_CHANGE;
dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp);
if (imx6_pcie->variant != IMX7D) {
/*
* On i.MX7, DIRECT_SPEED_CHANGE behaves differently
* from i.MX6 family when no link speed transition
* occurs and we go Gen1 -> yep, Gen1. The difference
* is that, in such case, it will not be cleared by HW
* which will cause the following code to report false
* failure.
*/
ret = imx6_pcie_wait_for_speed_change(imx6_pcie);
if (ret) {
dev_err(dev, "Failed to bring link up!\n");
goto err_reset_phy;
}
}
/* Make sure link training is finished as well! */
ret = imx6_pcie_wait_for_link(imx6_pcie);
if (ret) {
dev_err(dev, "Failed to bring link up!\n");
goto err_reset_phy;
}
} else {
dev_info(dev, "Link: Gen2 disabled\n");
}
tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCSR);
dev_info(dev, "Link up, Gen%i\n", (tmp >> 16) & 0xf);
return 0;
err_reset_phy:
dev_dbg(dev, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n",
dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R0),
dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1));
imx6_pcie_reset_phy(imx6_pcie);
return ret;
}
static int imx6_pcie_host_init(struct pcie_port *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct imx6_pcie *imx6_pcie = to_imx6_pcie(pci);
imx6_pcie_assert_core_reset(imx6_pcie);
imx6_pcie_init_phy(imx6_pcie);
imx6_pcie_deassert_core_reset(imx6_pcie);
imx6_setup_phy_mpll(imx6_pcie);
dw_pcie_setup_rc(pp);
imx6_pcie_establish_link(imx6_pcie);
if (IS_ENABLED(CONFIG_PCI_MSI))
dw_pcie_msi_init(pp);
return 0;
}
static int imx6_pcie_link_up(struct dw_pcie *pci)
{
return dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1) &
PCIE_PHY_DEBUG_R1_XMLH_LINK_UP;
}
static const struct dw_pcie_host_ops imx6_pcie_host_ops = {
.host_init = imx6_pcie_host_init,
};
static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
struct platform_device *pdev)
{
struct dw_pcie *pci = imx6_pcie->pci;
struct pcie_port *pp = &pci->pp;
struct device *dev = &pdev->dev;
int ret;
if (IS_ENABLED(CONFIG_PCI_MSI)) {
pp->msi_irq = platform_get_irq_byname(pdev, "msi");
if (pp->msi_irq <= 0) {
dev_err(dev, "failed to get MSI irq\n");
return -ENODEV;
}
}
pp->ops = &imx6_pcie_host_ops;
ret = dw_pcie_host_init(pp);
if (ret) {
dev_err(dev, "failed to initialize host\n");
return ret;
}
return 0;
}
static const struct dw_pcie_ops dw_pcie_ops = {
.link_up = imx6_pcie_link_up,
};
#ifdef CONFIG_PM_SLEEP
static void imx6_pcie_ltssm_disable(struct device *dev)
{
struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
switch (imx6_pcie->variant) {
case IMX6SX:
case IMX6QP:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6Q_GPR12_PCIE_CTL_2, 0);
break;
case IMX7D:
reset_control_assert(imx6_pcie->apps_reset);
break;
default:
dev_err(dev, "ltssm_disable not supported\n");
}
}
static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
{
struct device *dev = imx6_pcie->pci->dev;
/* Some variants have a turnoff reset in DT */
if (imx6_pcie->turnoff_reset) {
reset_control_assert(imx6_pcie->turnoff_reset);
reset_control_deassert(imx6_pcie->turnoff_reset);
goto pm_turnoff_sleep;
}
/* Others poke directly at IOMUXC registers */
switch (imx6_pcie->variant) {
case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_PM_TURN_OFF,
IMX6SX_GPR12_PCIE_PM_TURN_OFF);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);
break;
default:
dev_err(dev, "PME_Turn_Off not implemented\n");
return;
}
/*
* Components with an upstream port must respond to
* PME_Turn_Off with PME_TO_Ack but we can't check.
*
* The standard recommends a 1-10ms timeout after which to
* proceed anyway as if acks were received.
*/
pm_turnoff_sleep:
usleep_range(1000, 10000);
}
static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
{
clk_disable_unprepare(imx6_pcie->pcie);
clk_disable_unprepare(imx6_pcie->pcie_phy);
clk_disable_unprepare(imx6_pcie->pcie_bus);
switch (imx6_pcie->variant) {
case IMX6SX:
clk_disable_unprepare(imx6_pcie->pcie_inbound_axi);
break;
case IMX7D:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
break;
default:
break;
}
}
static inline bool imx6_pcie_supports_suspend(struct imx6_pcie *imx6_pcie)
{
return (imx6_pcie->variant == IMX7D ||
imx6_pcie->variant == IMX6SX);
}
static int imx6_pcie_suspend_noirq(struct device *dev)
{
struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
if (!imx6_pcie_supports_suspend(imx6_pcie))
return 0;
imx6_pcie_pm_turnoff(imx6_pcie);
imx6_pcie_clk_disable(imx6_pcie);
imx6_pcie_ltssm_disable(dev);
return 0;
}
static int imx6_pcie_resume_noirq(struct device *dev)
{
int ret;
struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
struct pcie_port *pp = &imx6_pcie->pci->pp;
if (!imx6_pcie_supports_suspend(imx6_pcie))
return 0;
imx6_pcie_assert_core_reset(imx6_pcie);
imx6_pcie_init_phy(imx6_pcie);
imx6_pcie_deassert_core_reset(imx6_pcie);
dw_pcie_setup_rc(pp);
ret = imx6_pcie_establish_link(imx6_pcie);
if (ret < 0)
dev_info(dev, "pcie link is down after resume.\n");
return 0;
}
#endif
static const struct dev_pm_ops imx6_pcie_pm_ops = {
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx6_pcie_suspend_noirq,
imx6_pcie_resume_noirq)
};
static int imx6_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct dw_pcie *pci;
struct imx6_pcie *imx6_pcie;
struct resource *dbi_base;
struct device_node *node = dev->of_node;
int ret;
imx6_pcie = devm_kzalloc(dev, sizeof(*imx6_pcie), GFP_KERNEL);
if (!imx6_pcie)
return -ENOMEM;
pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
if (!pci)
return -ENOMEM;
pci->dev = dev;
pci->ops = &dw_pcie_ops;
imx6_pcie->pci = pci;
imx6_pcie->variant =
(enum imx6_pcie_variants)of_device_get_match_data(dev);
dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
pci->dbi_base = devm_ioremap_resource(dev, dbi_base);
if (IS_ERR(pci->dbi_base))
return PTR_ERR(pci->dbi_base);
/* Fetch GPIOs */
imx6_pcie->reset_gpio = of_get_named_gpio(node, "reset-gpio", 0);
imx6_pcie->gpio_active_high = of_property_read_bool(node,
"reset-gpio-active-high");
if (gpio_is_valid(imx6_pcie->reset_gpio)) {
ret = devm_gpio_request_one(dev, imx6_pcie->reset_gpio,
imx6_pcie->gpio_active_high ?
GPIOF_OUT_INIT_HIGH :
GPIOF_OUT_INIT_LOW,
"PCIe reset");
if (ret) {
dev_err(dev, "unable to get reset gpio\n");
return ret;
}
} else if (imx6_pcie->reset_gpio == -EPROBE_DEFER) {
return imx6_pcie->reset_gpio;
}
/* Fetch clocks */
imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
if (IS_ERR(imx6_pcie->pcie_phy)) {
dev_err(dev, "pcie_phy clock source missing or invalid\n");
return PTR_ERR(imx6_pcie->pcie_phy);
}
imx6_pcie->pcie_bus = devm_clk_get(dev, "pcie_bus");
if (IS_ERR(imx6_pcie->pcie_bus)) {
dev_err(dev, "pcie_bus clock source missing or invalid\n");
return PTR_ERR(imx6_pcie->pcie_bus);
}
imx6_pcie->pcie = devm_clk_get(dev, "pcie");
if (IS_ERR(imx6_pcie->pcie)) {
dev_err(dev, "pcie clock source missing or invalid\n");
return PTR_ERR(imx6_pcie->pcie);
}
switch (imx6_pcie->variant) {
case IMX6SX:
imx6_pcie->pcie_inbound_axi = devm_clk_get(dev,
"pcie_inbound_axi");
if (IS_ERR(imx6_pcie->pcie_inbound_axi)) {
dev_err(dev, "pcie_inbound_axi clock missing or invalid\n");
return PTR_ERR(imx6_pcie->pcie_inbound_axi);
}
break;
case IMX7D:
imx6_pcie->pciephy_reset = devm_reset_control_get_exclusive(dev,
"pciephy");
if (IS_ERR(imx6_pcie->pciephy_reset)) {
dev_err(dev, "Failed to get PCIEPHY reset control\n");
return PTR_ERR(imx6_pcie->pciephy_reset);
}
imx6_pcie->apps_reset = devm_reset_control_get_exclusive(dev,
"apps");
if (IS_ERR(imx6_pcie->apps_reset)) {
dev_err(dev, "Failed to get PCIE APPS reset control\n");
return PTR_ERR(imx6_pcie->apps_reset);
}
break;
default:
break;
}
/* Grab turnoff reset */
imx6_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff");
if (IS_ERR(imx6_pcie->turnoff_reset)) {
dev_err(dev, "Failed to get TURNOFF reset control\n");
return PTR_ERR(imx6_pcie->turnoff_reset);
}
/* Grab GPR config register range */
imx6_pcie->iomuxc_gpr =
syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
if (IS_ERR(imx6_pcie->iomuxc_gpr)) {
dev_err(dev, "unable to find iomuxc registers\n");
return PTR_ERR(imx6_pcie->iomuxc_gpr);
}
/* Grab PCIe PHY Tx Settings */
if (of_property_read_u32(node, "fsl,tx-deemph-gen1",
&imx6_pcie->tx_deemph_gen1))
imx6_pcie->tx_deemph_gen1 = 0;
if (of_property_read_u32(node, "fsl,tx-deemph-gen2-3p5db",
&imx6_pcie->tx_deemph_gen2_3p5db))
imx6_pcie->tx_deemph_gen2_3p5db = 0;
if (of_property_read_u32(node, "fsl,tx-deemph-gen2-6db",
&imx6_pcie->tx_deemph_gen2_6db))
imx6_pcie->tx_deemph_gen2_6db = 20;
if (of_property_read_u32(node, "fsl,tx-swing-full",
&imx6_pcie->tx_swing_full))
imx6_pcie->tx_swing_full = 127;
if (of_property_read_u32(node, "fsl,tx-swing-low",
&imx6_pcie->tx_swing_low))
imx6_pcie->tx_swing_low = 127;
/* Limit link speed */
ret = of_property_read_u32(node, "fsl,max-link-speed",
&imx6_pcie->link_gen);
if (ret)
imx6_pcie->link_gen = 1;
imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie");
if (IS_ERR(imx6_pcie->vpcie)) {
if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER)
return -EPROBE_DEFER;
imx6_pcie->vpcie = NULL;
}
platform_set_drvdata(pdev, imx6_pcie);
ret = imx6_pcie_attach_pd(dev);
if (ret)
return ret;
ret = imx6_add_pcie_port(imx6_pcie, pdev);
if (ret < 0)
return ret;
return 0;
}
static void imx6_pcie_shutdown(struct platform_device *pdev)
{
struct imx6_pcie *imx6_pcie = platform_get_drvdata(pdev);
/* bring down link, so bootloader gets clean state in case of reboot */
imx6_pcie_assert_core_reset(imx6_pcie);
}
static const struct of_device_id imx6_pcie_of_match[] = {
{ .compatible = "fsl,imx6q-pcie", .data = (void *)IMX6Q, },
{ .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, },
{ .compatible = "fsl,imx6qp-pcie", .data = (void *)IMX6QP, },
{ .compatible = "fsl,imx7d-pcie", .data = (void *)IMX7D, },
{},
};
static struct platform_driver imx6_pcie_driver = {
.driver = {
.name = "imx6q-pcie",
.of_match_table = imx6_pcie_of_match,
.suppress_bind_attrs = true,
.pm = &imx6_pcie_pm_ops,
},
.probe = imx6_pcie_probe,
.shutdown = imx6_pcie_shutdown,
};
static int __init imx6_pcie_init(void)
{
/*
* Since probe() can be deferred we need to make sure that
* hook_fault_code is not called after __init memory is freed
* by kernel and since imx6q_pcie_abort_handler() is a no-op,
* we can install the handler here without risking it
* accessing some uninitialized driver state.
*/
hook_fault_code(8, imx6q_pcie_abort_handler, SIGBUS, 0,
"external abort on non-linefetch");
return platform_driver_register(&imx6_pcie_driver);
}
device_initcall(imx6_pcie_init);
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