diff options
Diffstat (limited to 'drivers/mfd/ls2k-bmc-core.c')
| -rw-r--r-- | drivers/mfd/ls2k-bmc-core.c | 528 |
1 files changed, 528 insertions, 0 deletions
diff --git a/drivers/mfd/ls2k-bmc-core.c b/drivers/mfd/ls2k-bmc-core.c new file mode 100644 index 000000000000..e162b3c7c9f8 --- /dev/null +++ b/drivers/mfd/ls2k-bmc-core.c @@ -0,0 +1,528 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Loongson-2K Board Management Controller (BMC) Core Driver. + * + * Copyright (C) 2024-2025 Loongson Technology Corporation Limited. + * + * Authors: + * Chong Qiao <qiaochong@loongson.cn> + * Binbin Zhou <zhoubinbin@loongson.cn> + */ + +#include <linux/aperture.h> +#include <linux/bitfield.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/iopoll.h> +#include <linux/kbd_kern.h> +#include <linux/kernel.h> +#include <linux/mfd/core.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/pci_ids.h> +#include <linux/platform_data/simplefb.h> +#include <linux/platform_device.h> +#include <linux/stop_machine.h> +#include <linux/vt_kern.h> + +/* LS2K BMC resources */ +#define LS2K_DISPLAY_RES_START (SZ_16M + SZ_2M) +#define LS2K_IPMI_RES_SIZE 0x1C +#define LS2K_IPMI0_RES_START (SZ_16M + 0xF00000) +#define LS2K_IPMI1_RES_START (LS2K_IPMI0_RES_START + LS2K_IPMI_RES_SIZE) +#define LS2K_IPMI2_RES_START (LS2K_IPMI1_RES_START + LS2K_IPMI_RES_SIZE) +#define LS2K_IPMI3_RES_START (LS2K_IPMI2_RES_START + LS2K_IPMI_RES_SIZE) +#define LS2K_IPMI4_RES_START (LS2K_IPMI3_RES_START + LS2K_IPMI_RES_SIZE) + +#define LS7A_PCI_CFG_SIZE 0x100 + +/* LS7A bridge registers */ +#define LS7A_PCIE_PORT_CTL0 0x0 +#define LS7A_PCIE_PORT_STS1 0xC +#define LS7A_GEN2_CTL 0x80C +#define LS7A_SYMBOL_TIMER 0x71C + +/* Bits of LS7A_PCIE_PORT_CTL0 */ +#define LS2K_BMC_PCIE_LTSSM_ENABLE BIT(3) + +/* Bits of LS7A_PCIE_PORT_STS1 */ +#define LS2K_BMC_PCIE_LTSSM_STS GENMASK(5, 0) +#define LS2K_BMC_PCIE_CONNECTED 0x11 + +#define LS2K_BMC_PCIE_DELAY_US 1000 +#define LS2K_BMC_PCIE_TIMEOUT_US 1000000 + +/* Bits of LS7A_GEN2_CTL */ +#define LS7A_GEN2_SPEED_CHANG BIT(17) +#define LS7A_CONF_PHY_TX BIT(18) + +/* Bits of LS7A_SYMBOL_TIMER */ +#define LS7A_MASK_LEN_MATCH BIT(26) + +/* Interval between interruptions */ +#define LS2K_BMC_INT_INTERVAL (60 * HZ) + +/* Maximum time to wait for U-Boot and DDR to be ready with ms. */ +#define LS2K_BMC_RESET_WAIT_TIME 10000 + +/* It's an experience value */ +#define LS7A_BAR0_CHECK_MAX_TIMES 2000 + +#define PCI_REG_STRIDE 0x4 + +#define LS2K_BMC_RESET_GPIO 14 +#define LOONGSON_GPIO_REG_BASE 0x1FE00500 +#define LOONGSON_GPIO_REG_SIZE 0x18 +#define LOONGSON_GPIO_OEN 0x0 +#define LOONGSON_GPIO_FUNC 0x4 +#define LOONGSON_GPIO_INTPOL 0x10 +#define LOONGSON_GPIO_INTEN 0x14 + +#define LOONGSON_IO_INT_BASE 16 +#define LS2K_BMC_RESET_GPIO_INT_VEC (LS2K_BMC_RESET_GPIO % 8) +#define LS2K_BMC_RESET_GPIO_GSI (LOONGSON_IO_INT_BASE + LS2K_BMC_RESET_GPIO_INT_VEC) + +enum { + LS2K_BMC_DISPLAY, + LS2K_BMC_IPMI0, + LS2K_BMC_IPMI1, + LS2K_BMC_IPMI2, + LS2K_BMC_IPMI3, + LS2K_BMC_IPMI4, +}; + +static struct resource ls2k_display_resources[] = { + DEFINE_RES_MEM_NAMED(LS2K_DISPLAY_RES_START, SZ_4M, "simpledrm-res"), +}; + +static struct resource ls2k_ipmi0_resources[] = { + DEFINE_RES_MEM_NAMED(LS2K_IPMI0_RES_START, LS2K_IPMI_RES_SIZE, "ipmi0-res"), +}; + +static struct resource ls2k_ipmi1_resources[] = { + DEFINE_RES_MEM_NAMED(LS2K_IPMI1_RES_START, LS2K_IPMI_RES_SIZE, "ipmi1-res"), +}; + +static struct resource ls2k_ipmi2_resources[] = { + DEFINE_RES_MEM_NAMED(LS2K_IPMI2_RES_START, LS2K_IPMI_RES_SIZE, "ipmi2-res"), +}; + +static struct resource ls2k_ipmi3_resources[] = { + DEFINE_RES_MEM_NAMED(LS2K_IPMI3_RES_START, LS2K_IPMI_RES_SIZE, "ipmi3-res"), +}; + +static struct resource ls2k_ipmi4_resources[] = { + DEFINE_RES_MEM_NAMED(LS2K_IPMI4_RES_START, LS2K_IPMI_RES_SIZE, "ipmi4-res"), +}; + +static struct mfd_cell ls2k_bmc_cells[] = { + [LS2K_BMC_DISPLAY] = { + .name = "simple-framebuffer", + .num_resources = ARRAY_SIZE(ls2k_display_resources), + .resources = ls2k_display_resources + }, + [LS2K_BMC_IPMI0] = { + .name = "ls2k-ipmi-si", + .num_resources = ARRAY_SIZE(ls2k_ipmi0_resources), + .resources = ls2k_ipmi0_resources + }, + [LS2K_BMC_IPMI1] = { + .name = "ls2k-ipmi-si", + .num_resources = ARRAY_SIZE(ls2k_ipmi1_resources), + .resources = ls2k_ipmi1_resources + }, + [LS2K_BMC_IPMI2] = { + .name = "ls2k-ipmi-si", + .num_resources = ARRAY_SIZE(ls2k_ipmi2_resources), + .resources = ls2k_ipmi2_resources + }, + [LS2K_BMC_IPMI3] = { + .name = "ls2k-ipmi-si", + .num_resources = ARRAY_SIZE(ls2k_ipmi3_resources), + .resources = ls2k_ipmi3_resources + }, + [LS2K_BMC_IPMI4] = { + .name = "ls2k-ipmi-si", + .num_resources = ARRAY_SIZE(ls2k_ipmi4_resources), + .resources = ls2k_ipmi4_resources + }, +}; + +/* Index of the BMC PCI configuration space to be restored at BMC reset. */ +struct ls2k_bmc_pci_data { + u32 pci_command; + u32 base_address0; + u32 interrupt_line; +}; + +/* Index of the parent PCI configuration space to be restored at BMC reset. */ +struct ls2k_bmc_bridge_pci_data { + u32 pci_command; + u32 base_address[6]; + u32 rom_addreess; + u32 interrupt_line; + u32 msi_hi; + u32 msi_lo; + u32 devctl; + u32 linkcap; + u32 linkctl_sts; + u32 symbol_timer; + u32 gen2_ctrl; +}; + +struct ls2k_bmc_ddata { + struct device *dev; + struct work_struct bmc_reset_work; + struct ls2k_bmc_pci_data bmc_pci_data; + struct ls2k_bmc_bridge_pci_data bridge_pci_data; +}; + +static bool ls2k_bmc_bar0_addr_is_set(struct pci_dev *pdev) +{ + u32 addr; + + pci_read_config_dword(pdev, PCI_BASE_ADDRESS_0, &addr); + + return addr & PCI_BASE_ADDRESS_MEM_MASK ? true : false; +} + +static bool ls2k_bmc_pcie_is_connected(struct pci_dev *parent, struct ls2k_bmc_ddata *ddata) +{ + void __iomem *base; + int val, ret; + + base = pci_iomap(parent, 0, LS7A_PCI_CFG_SIZE); + if (!base) + return false; + + val = readl(base + LS7A_PCIE_PORT_CTL0); + writel(val | LS2K_BMC_PCIE_LTSSM_ENABLE, base + LS7A_PCIE_PORT_CTL0); + + ret = readl_poll_timeout_atomic(base + LS7A_PCIE_PORT_STS1, val, + (val & LS2K_BMC_PCIE_LTSSM_STS) == LS2K_BMC_PCIE_CONNECTED, + LS2K_BMC_PCIE_DELAY_US, LS2K_BMC_PCIE_TIMEOUT_US); + if (ret) { + pci_iounmap(parent, base); + dev_err(ddata->dev, "PCI-E training failed status=0x%x\n", val); + return false; + } + + pci_iounmap(parent, base); + return true; +} + +static void ls2k_bmc_restore_bridge_pci_data(struct pci_dev *parent, struct ls2k_bmc_ddata *ddata) +{ + int base, i = 0; + + pci_write_config_dword(parent, PCI_COMMAND, ddata->bridge_pci_data.pci_command); + + for (base = PCI_BASE_ADDRESS_0; base <= PCI_BASE_ADDRESS_5; base += PCI_REG_STRIDE, i++) + pci_write_config_dword(parent, base, ddata->bridge_pci_data.base_address[i]); + + pci_write_config_dword(parent, PCI_ROM_ADDRESS, ddata->bridge_pci_data.rom_addreess); + pci_write_config_dword(parent, PCI_INTERRUPT_LINE, ddata->bridge_pci_data.interrupt_line); + + pci_write_config_dword(parent, parent->msi_cap + PCI_MSI_ADDRESS_LO, + ddata->bridge_pci_data.msi_lo); + pci_write_config_dword(parent, parent->msi_cap + PCI_MSI_ADDRESS_HI, + ddata->bridge_pci_data.msi_hi); + pci_write_config_dword(parent, parent->pcie_cap + PCI_EXP_DEVCTL, + ddata->bridge_pci_data.devctl); + pci_write_config_dword(parent, parent->pcie_cap + PCI_EXP_LNKCAP, + ddata->bridge_pci_data.linkcap); + pci_write_config_dword(parent, parent->pcie_cap + PCI_EXP_LNKCTL, + ddata->bridge_pci_data.linkctl_sts); + + pci_write_config_dword(parent, LS7A_GEN2_CTL, ddata->bridge_pci_data.gen2_ctrl); + pci_write_config_dword(parent, LS7A_SYMBOL_TIMER, ddata->bridge_pci_data.symbol_timer); +} + +static int ls2k_bmc_recover_pci_data(void *data) +{ + struct ls2k_bmc_ddata *ddata = data; + struct pci_dev *pdev = to_pci_dev(ddata->dev); + struct pci_dev *parent = pdev->bus->self; + u32 i; + + /* + * Clear the bus, io and mem resources of the PCI-E bridge to zero, so that + * the processor can not access the LS2K PCI-E port, to avoid crashing due to + * the lack of return signal from accessing the LS2K PCI-E port. + */ + pci_write_config_dword(parent, PCI_BASE_ADDRESS_2, 0); + pci_write_config_dword(parent, PCI_BASE_ADDRESS_3, 0); + pci_write_config_dword(parent, PCI_BASE_ADDRESS_4, 0); + + /* + * When the LS2K BMC is reset, the LS7A PCI-E port is also reset, and its PCI + * BAR0 register is cleared. Due to the time gap between the GPIO interrupt + * generation and the LS2K BMC reset, the LS7A PCI BAR0 register is read to + * determine whether the reset has begun. + */ + for (i = LS7A_BAR0_CHECK_MAX_TIMES; i > 0 ; i--) { + if (!ls2k_bmc_bar0_addr_is_set(parent)) + break; + mdelay(1); + }; + + if (i == 0) + return false; + + ls2k_bmc_restore_bridge_pci_data(parent, ddata); + + /* Check if PCI-E is connected */ + if (!ls2k_bmc_pcie_is_connected(parent, ddata)) + return false; + + /* Waiting for U-Boot and DDR ready */ + mdelay(LS2K_BMC_RESET_WAIT_TIME); + if (!ls2k_bmc_bar0_addr_is_set(parent)) + return false; + + /* Restore LS2K BMC PCI-E config data */ + pci_write_config_dword(pdev, PCI_COMMAND, ddata->bmc_pci_data.pci_command); + pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0, ddata->bmc_pci_data.base_address0); + pci_write_config_dword(pdev, PCI_INTERRUPT_LINE, ddata->bmc_pci_data.interrupt_line); + + return 0; +} + +static void ls2k_bmc_events_fn(struct work_struct *work) +{ + struct ls2k_bmc_ddata *ddata = container_of(work, struct ls2k_bmc_ddata, bmc_reset_work); + + /* + * The PCI-E is lost when the BMC resets, at which point access to the PCI-E + * from other CPUs is suspended to prevent a crash. + */ + stop_machine(ls2k_bmc_recover_pci_data, ddata, NULL); + + if (IS_ENABLED(CONFIG_VT)) { + /* Re-push the display due to previous PCI-E loss. */ + set_console(vt_move_to_console(MAX_NR_CONSOLES - 1, 1)); + } +} + +static irqreturn_t ls2k_bmc_interrupt(int irq, void *arg) +{ + struct ls2k_bmc_ddata *ddata = arg; + static unsigned long last_jiffies; + + if (system_state != SYSTEM_RUNNING) + return IRQ_HANDLED; + + /* Skip interrupt in LS2K_BMC_INT_INTERVAL */ + if (time_after(jiffies, last_jiffies + LS2K_BMC_INT_INTERVAL)) { + schedule_work(&ddata->bmc_reset_work); + last_jiffies = jiffies; + } + + return IRQ_HANDLED; +} + +/* + * Saves the BMC parent device (LS7A) and its own PCI configuration space registers + * that need to be restored after BMC reset. + */ +static void ls2k_bmc_save_pci_data(struct pci_dev *pdev, struct ls2k_bmc_ddata *ddata) +{ + struct pci_dev *parent = pdev->bus->self; + int base, i = 0; + + pci_read_config_dword(parent, PCI_COMMAND, &ddata->bridge_pci_data.pci_command); + + for (base = PCI_BASE_ADDRESS_0; base <= PCI_BASE_ADDRESS_5; base += PCI_REG_STRIDE, i++) + pci_read_config_dword(parent, base, &ddata->bridge_pci_data.base_address[i]); + + pci_read_config_dword(parent, PCI_ROM_ADDRESS, &ddata->bridge_pci_data.rom_addreess); + pci_read_config_dword(parent, PCI_INTERRUPT_LINE, &ddata->bridge_pci_data.interrupt_line); + + pci_read_config_dword(parent, parent->msi_cap + PCI_MSI_ADDRESS_LO, + &ddata->bridge_pci_data.msi_lo); + pci_read_config_dword(parent, parent->msi_cap + PCI_MSI_ADDRESS_HI, + &ddata->bridge_pci_data.msi_hi); + + pci_read_config_dword(parent, parent->pcie_cap + PCI_EXP_DEVCTL, + &ddata->bridge_pci_data.devctl); + pci_read_config_dword(parent, parent->pcie_cap + PCI_EXP_LNKCAP, + &ddata->bridge_pci_data.linkcap); + pci_read_config_dword(parent, parent->pcie_cap + PCI_EXP_LNKCTL, + &ddata->bridge_pci_data.linkctl_sts); + + pci_read_config_dword(parent, LS7A_GEN2_CTL, &ddata->bridge_pci_data.gen2_ctrl); + ddata->bridge_pci_data.gen2_ctrl |= FIELD_PREP(LS7A_GEN2_SPEED_CHANG, 0x1) | + FIELD_PREP(LS7A_CONF_PHY_TX, 0x0); + + pci_read_config_dword(parent, LS7A_SYMBOL_TIMER, &ddata->bridge_pci_data.symbol_timer); + ddata->bridge_pci_data.symbol_timer |= LS7A_MASK_LEN_MATCH; + + pci_read_config_dword(pdev, PCI_COMMAND, &ddata->bmc_pci_data.pci_command); + pci_read_config_dword(pdev, PCI_BASE_ADDRESS_0, &ddata->bmc_pci_data.base_address0); + pci_read_config_dword(pdev, PCI_INTERRUPT_LINE, &ddata->bmc_pci_data.interrupt_line); +} + +static int ls2k_bmc_init(struct ls2k_bmc_ddata *ddata) +{ + struct pci_dev *pdev = to_pci_dev(ddata->dev); + void __iomem *gpio_base; + int gpio_irq, ret, val; + + ls2k_bmc_save_pci_data(pdev, ddata); + + INIT_WORK(&ddata->bmc_reset_work, ls2k_bmc_events_fn); + + ret = devm_request_irq(&pdev->dev, pdev->irq, ls2k_bmc_interrupt, + IRQF_SHARED | IRQF_TRIGGER_FALLING, "ls2kbmc pcie", ddata); + if (ret) { + dev_err(ddata->dev, "Failed to request LS2KBMC PCI-E IRQ %d.\n", pdev->irq); + return ret; + } + + gpio_base = ioremap(LOONGSON_GPIO_REG_BASE, LOONGSON_GPIO_REG_SIZE); + if (!gpio_base) + return -ENOMEM; + + /* Disable GPIO output */ + val = readl(gpio_base + LOONGSON_GPIO_OEN); + writel(val | BIT(LS2K_BMC_RESET_GPIO), gpio_base + LOONGSON_GPIO_OEN); + + /* Enable GPIO functionality */ + val = readl(gpio_base + LOONGSON_GPIO_FUNC); + writel(val & ~BIT(LS2K_BMC_RESET_GPIO), gpio_base + LOONGSON_GPIO_FUNC); + + /* Set GPIO interrupts to low-level active */ + val = readl(gpio_base + LOONGSON_GPIO_INTPOL); + writel(val & ~BIT(LS2K_BMC_RESET_GPIO), gpio_base + LOONGSON_GPIO_INTPOL); + + /* Enable GPIO interrupts */ + val = readl(gpio_base + LOONGSON_GPIO_INTEN); + writel(val | BIT(LS2K_BMC_RESET_GPIO), gpio_base + LOONGSON_GPIO_INTEN); + + iounmap(gpio_base); + + /* + * Since gpio_chip->to_irq is not implemented in the Loongson-3 GPIO driver, + * acpi_register_gsi() is used to obtain the GPIO IRQ. The GPIO interrupt is a + * watchdog interrupt that is triggered when the BMC resets. + */ + gpio_irq = acpi_register_gsi(NULL, LS2K_BMC_RESET_GPIO_GSI, ACPI_EDGE_SENSITIVE, + ACPI_ACTIVE_LOW); + if (gpio_irq < 0) + return gpio_irq; + + ret = devm_request_irq(ddata->dev, gpio_irq, ls2k_bmc_interrupt, + IRQF_SHARED | IRQF_TRIGGER_FALLING, "ls2kbmc gpio", ddata); + if (ret) + dev_err(ddata->dev, "Failed to request LS2KBMC GPIO IRQ %d.\n", gpio_irq); + + acpi_unregister_gsi(LS2K_BMC_RESET_GPIO_GSI); + return ret; +} + +/* + * Currently the Loongson-2K BMC hardware does not have an I2C interface to adapt to the + * resolution. We set the resolution by presetting "video=1280x1024-16@2M" to the BMC memory. + */ +static int ls2k_bmc_parse_mode(struct pci_dev *pdev, struct simplefb_platform_data *pd) +{ + char *mode; + int depth, ret; + + /* The last 16M of PCI BAR0 is used to store the resolution string. */ + mode = devm_ioremap(&pdev->dev, pci_resource_start(pdev, 0) + SZ_16M, SZ_16M); + if (!mode) + return -ENOMEM; + + /* The resolution field starts with the flag "video=". */ + if (!strncmp(mode, "video=", 6)) + mode = mode + 6; + + ret = kstrtoint(strsep(&mode, "x"), 10, &pd->width); + if (ret) + return ret; + + ret = kstrtoint(strsep(&mode, "-"), 10, &pd->height); + if (ret) + return ret; + + ret = kstrtoint(strsep(&mode, "@"), 10, &depth); + if (ret) + return ret; + + pd->stride = pd->width * depth / 8; + pd->format = depth == 32 ? "a8r8g8b8" : "r5g6b5"; + + return 0; +} + +static int ls2k_bmc_probe(struct pci_dev *dev, const struct pci_device_id *id) +{ + struct simplefb_platform_data pd; + struct ls2k_bmc_ddata *ddata; + resource_size_t base; + int ret; + + ret = pci_enable_device(dev); + if (ret) + return ret; + + ddata = devm_kzalloc(&dev->dev, sizeof(*ddata), GFP_KERNEL); + if (IS_ERR(ddata)) { + ret = -ENOMEM; + goto disable_pci; + } + + ddata->dev = &dev->dev; + + ret = ls2k_bmc_init(ddata); + if (ret) + goto disable_pci; + + ret = ls2k_bmc_parse_mode(dev, &pd); + if (ret) + goto disable_pci; + + ls2k_bmc_cells[LS2K_BMC_DISPLAY].platform_data = &pd; + ls2k_bmc_cells[LS2K_BMC_DISPLAY].pdata_size = sizeof(pd); + base = dev->resource[0].start + LS2K_DISPLAY_RES_START; + + /* Remove conflicting efifb device */ + ret = aperture_remove_conflicting_devices(base, SZ_4M, "simple-framebuffer"); + if (ret) { + dev_err(&dev->dev, "Failed to removed firmware framebuffers: %d\n", ret); + goto disable_pci; + } + + return devm_mfd_add_devices(&dev->dev, PLATFORM_DEVID_AUTO, + ls2k_bmc_cells, ARRAY_SIZE(ls2k_bmc_cells), + &dev->resource[0], 0, NULL); + +disable_pci: + pci_disable_device(dev); + return ret; +} + +static void ls2k_bmc_remove(struct pci_dev *dev) +{ + pci_disable_device(dev); +} + +static struct pci_device_id ls2k_bmc_devices[] = { + { PCI_DEVICE(PCI_VENDOR_ID_LOONGSON, 0x1a05) }, + { } +}; +MODULE_DEVICE_TABLE(pci, ls2k_bmc_devices); + +static struct pci_driver ls2k_bmc_driver = { + .name = "ls2k-bmc", + .id_table = ls2k_bmc_devices, + .probe = ls2k_bmc_probe, + .remove = ls2k_bmc_remove, +}; +module_pci_driver(ls2k_bmc_driver); + +MODULE_DESCRIPTION("Loongson-2K Board Management Controller (BMC) Core driver"); +MODULE_AUTHOR("Loongson Technology Corporation Limited"); +MODULE_LICENSE("GPL"); |