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/*
* PCIe host controller driver for Freescale i.MX6 SoCs
*
* Copyright (C) 2013 Kosagi
* http://www.kosagi.com
*
* Author: Sean Cross <xobs@kosagi.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#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/module.h>
#include <linux/of_gpio.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/resource.h>
#include <linux/signal.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include "pcie-designware.h"
#define to_imx6_pcie(x) container_of(x, struct imx6_pcie, pp)
struct imx6_pcie {
int reset_gpio;
struct clk *pcie_bus;
struct clk *pcie_phy;
struct clk *pcie;
struct pcie_port pp;
struct regmap *iomuxc_gpr;
void __iomem *mem_base;
};
/* 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_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(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);
return pcie_phy_poll_ack(dbi_base, 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);
return pcie_phy_poll_ack(dbi_base, 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;
}
/* Added for PCI abort handling */
static int imx6q_pcie_abort_handler(unsigned long addr,
unsigned int fsr, struct pt_regs *regs)
{
return 0;
}
static int imx6_pcie_assert_core_reset(struct pcie_port *pp)
{
struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
u32 val, gpr1, gpr12;
/*
* If the bootloader already enabled the link we need some special
* handling to get the core back into a state where it is safe to
* touch it for configuration. As there is no dedicated reset signal
* wired up for MX6QDL, we need to manually force LTSSM into "detect"
* state before completely disabling LTSSM, which is a prerequisite
* for core configuration.
*
* If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong
* indication that the bootloader activated the link.
*/
regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1);
regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12);
if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) &&
(gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) {
val = readl(pp->dbi_base + PCIE_PL_PFLR);
val &= ~PCIE_PL_PFLR_LINK_STATE_MASK;
val |= PCIE_PL_PFLR_FORCE_LINK;
writel(val, pp->dbi_base + PCIE_PL_PFLR);
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
}
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);
return 0;
}
static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
{
struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
int ret;
ret = clk_prepare_enable(imx6_pcie->pcie_phy);
if (ret) {
dev_err(pp->dev, "unable to enable pcie_phy clock\n");
goto err_pcie_phy;
}
ret =
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