--- /dev/null
+/*
+ * 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/io.h>
+#include <asm/sizes.h>
+#include <errno.h>
+
+#define PCI_ACCESS_READ 0
+#define PCI_ACCESS_WRITE 1
+
+#define MX6_DBI_ADDR 0x01ffc000
+#define MX6_DBI_SIZE 0x4000
+#define MX6_IO_ADDR 0x01000000
+#define MX6_IO_SIZE 0x100000
+#define MX6_MEM_ADDR 0x01100000
+#define MX6_MEM_SIZE 0xe00000
+#define MX6_ROOT_ADDR 0x01f00000
+#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)
+
+/* 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 ret;
+ }
+
+ 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;
+
+ setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_TEST_POWERDOWN);
+ clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_REF_SSP_EN);
+
+ 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);
+
+ 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;
+}
+
+static int imx6_pcie_deassert_core_reset(void)
+{
+ struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR;
+
+ /* FIXME: Power-up GPIO goes here. */
+
+ /* Enable PCIe */
+ clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_TEST_POWERDOWN);
+ setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_REF_SSP_EN);
+
+ enable_pcie_clock();
+
+ /*
+ * Wait for the clock to settle a bit, when the clock are sourced
+ * from the CPU, we need about 30mS to settle.
+ */
+ mdelay(30);
+
+ /* FIXME: GPIO reset goes here */
+ mdelay(100);
+
+ 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 >= 2000) {
+ debug("phy link never came up\n");
+ 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();
+}
projects / u-boot.git / commitdiff