diff options
Diffstat (limited to 'drivers/pci/pcie_imx.c')
| -rw-r--r-- | drivers/pci/pcie_imx.c | 606 |
1 files changed, 606 insertions, 0 deletions
diff --git a/drivers/pci/pcie_imx.c b/drivers/pci/pcie_imx.c new file mode 100644 index 0000000..34377e9 --- /dev/null +++ b/drivers/pci/pcie_imx.c @@ -0,0 +1,606 @@ +/* + * 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 <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; +} + +__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; + + /* 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(50); + + 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 >= 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(); +} |