+// SPDX-License-Identifier: GPL-2.0
/*
* Freescale i.MX6 PCI Express Root-Complex driver
*
* 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 <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 <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_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
+#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_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_LINK_UP (1 << 4)
#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)
ret = imx_pcie_addr_valid(d);
if (ret) {
*val = 0xffffffff;
- return ret;
+ return 0;
}
va_address = get_bus_address(d, where);
/*
* Initial bus setup
*/
-static int imx6_pcie_assert_core_reset(void)
+static int imx6_pcie_assert_core_reset(bool prepare_for_boot)
{
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
+ /*
+ * 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.
+ */
+ if (is_mx6dq() && prepare_for_boot) {
+ u32 val, gpr1, gpr12;
+
+ gpr1 = readl(&iomuxc_regs->gpr[1]);
+ gpr12 = readl(&iomuxc_regs->gpr[12]);
+ if ((gpr1 & IOMUXC_GPR1_PCIE_REF_CLK_EN) &&
+ (gpr12 & IOMUXC_GPR12_PCIE_CTL_2)) {
+ val = readl(MX6_DBI_ADDR + PCIE_PL_PFLR);
+ val &= ~PCIE_PL_PFLR_LINK_STATE_MASK;
+ val |= PCIE_PL_PFLR_FORCE_LINK;
+
+ imx_pcie_fix_dabt_handler(true);
+ writel(val, MX6_DBI_ADDR + PCIE_PL_PFLR);
+ imx_pcie_fix_dabt_handler(false);
+
+ gpr12 &= ~IOMUXC_GPR12_PCIE_CTL_2;
+ writel(val, &iomuxc_regs->gpr[12]);
+ }
+ }
setbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_TEST_POWERDOWN);
clrbits_le32(&iomuxc_regs->gpr[1], IOMUXC_GPR1_REF_SSP_EN);
+#endif
return 0;
}
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) |
return 0;
}
+__weak int imx6_pcie_toggle_power(void)
+{
+#ifdef CONFIG_PCIE_IMX_POWER_GPIO
+ gpio_request(CONFIG_PCIE_IMX_POWER_GPIO, "pcie_power");
+ gpio_direction_output(CONFIG_PCIE_IMX_POWER_GPIO, 0);
+ mdelay(20);
+ gpio_set_value(CONFIG_PCIE_IMX_POWER_GPIO, 1);
+ mdelay(20);
+ gpio_free(CONFIG_PCIE_IMX_POWER_GPIO);
+#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_request(CONFIG_PCIE_IMX_PERST_GPIO, "pcie_reset");
+ gpio_direction_output(CONFIG_PCIE_IMX_PERST_GPIO, 0);
+ mdelay(20);
+ gpio_set_value(CONFIG_PCIE_IMX_PERST_GPIO, 1);
+ mdelay(20);
+ gpio_free(CONFIG_PCIE_IMX_PERST_GPIO);
+#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);
+ 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 30mS to settle.
+ * from the CPU, we need about 30 ms to settle.
*/
- mdelay(30);
+ 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
- /* FIXME: GPIO reset goes here */
- mdelay(100);
+ imx6_pcie_toggle_reset();
return 0;
}
uint32_t tmp;
int count = 0;
- imx6_pcie_assert_core_reset();
+ imx6_pcie_assert_core_reset(false);
imx6_pcie_init_phy();
imx6_pcie_deassert_core_reset();
imx_pcie_regions_setup();
+ /*
+ * By default, the subordinate is set equally to the secondary
+ * bus (0x01) when the RC boots.
+ * This means that theoretically, only bus 1 is reachable from the RC.
+ * Force the PCIe RC subordinate to 0xff, otherwise no downstream
+ * devices will be detected if the enumeration is applied strictly.
+ */
+ tmp = readl(MX6_DBI_ADDR + 0x18);
+ tmp |= (0xff << 16);
+ writel(tmp, MX6_DBI_ADDR + 0x18);
+
/*
* FIXME: Force the PCIe RC to Gen1 operation
* The RC must be forced into Gen1 mode before bringing the link
while (!imx6_pcie_link_up()) {
udelay(10);
count++;
- if (count >= 2000) {
- debug("phy link never came up\n");
+ 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));
}
}
+void imx_pcie_remove(void)
+{
+ imx6_pcie_assert_core_reset(true);
+}
+
/* Probe function. */
void pci_init_board(void)
{
projects / u-boot / blobdiff