diff options
Diffstat (limited to 'drivers/acpi/gtdt.c')
| -rw-r--r-- | drivers/acpi/gtdt.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/acpi/gtdt.c b/drivers/acpi/gtdt.c new file mode 100644 index 000000000000..699c9fd7e4ce --- /dev/null +++ b/drivers/acpi/gtdt.c @@ -0,0 +1,180 @@ +/* + * ARM Specific GTDT table Support + * + * Copyright (C) 2015, Linaro Ltd. + * Author: Fu Wei <fu.wei@linaro.org> + * Hanjun Guo <hanjun.guo@linaro.org> + * + * 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/acpi.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#include <clocksource/arm_arch_timer.h> + +static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags) +{ + int trigger, polarity; + + if (!interrupt) + return 0; + + trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE + : ACPI_LEVEL_SENSITIVE; + + polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW + : ACPI_ACTIVE_HIGH; + + return acpi_register_gsi(NULL, interrupt, trigger, polarity); +} + +struct arch_timer_data __initdata *arch_timer_data_p; + +static int __init arch_timer_data_init(struct acpi_table_header *table) +{ + struct acpi_table_gtdt *gtdt; + + gtdt = container_of(table, struct acpi_table_gtdt, header); + + arch_timer_data_p->phys_secure_ppi = + map_generic_timer_interrupt(gtdt->secure_el1_interrupt, + gtdt->secure_el1_flags); + + arch_timer_data_p->phys_nonsecure_ppi = + map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt, + gtdt->non_secure_el1_flags); + + arch_timer_data_p->virt_ppi = + map_generic_timer_interrupt(gtdt->virtual_timer_interrupt, + gtdt->virtual_timer_flags); + + arch_timer_data_p->hyp_ppi = + map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt, + gtdt->non_secure_el2_flags); + + arch_timer_data_p->c3stop = !(gtdt->non_secure_el1_flags & + ACPI_GTDT_ALWAYS_ON); + + return 0; +} + +/* Initialize the arch_timer_data struct for arm_arch_timer by GTDT info */ +int __init gtdt_arch_timer_data_init(struct arch_timer_data *data) +{ + if (acpi_disabled || !data) + return -EINVAL; + + arch_timer_data_p = data; + + return acpi_table_parse(ACPI_SIG_GTDT, arch_timer_data_init); +} + +/* + * Initialize a SBSA generic Watchdog platform device info from GTDT + * According to SBSA specification the size of refresh and control + * frames of SBSA Generic Watchdog is SZ_4K(Offset 0x000 – 0xFFF). + */ +static int __init gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd, + int index) +{ + struct platform_device *pdev; + int irq = map_generic_timer_interrupt(wd->timer_interrupt, + wd->timer_flags); + struct resource res[] = { + DEFINE_RES_IRQ_NAMED(irq, "ws0"), + DEFINE_RES_MEM_NAMED(wd->refresh_frame_address, SZ_4K, + "refresh"), + DEFINE_RES_MEM_NAMED(wd->control_frame_address, SZ_4K, + "control"), + }; + + pr_debug("GTDT: a Watchdog GT(0x%llx/0x%llx gsi:%u flags:0x%x)\n", + wd->refresh_frame_address, wd->control_frame_address, + wd->timer_interrupt, wd->timer_flags); + + if (!(wd->refresh_frame_address && + wd->control_frame_address && + wd->timer_interrupt)) { + pr_err("GTDT: failed geting the device info.\n"); + return -EINVAL; + } + + if (irq < 0) { + pr_err("GTDT: failed to register GSI of the Watchdog GT.\n"); + return -EINVAL; + } + + /* + * Add a platform device named "sbsa-gwdt" to match the platform driver. + * "sbsa-gwdt": SBSA(Server Base System Architecture) Generic Watchdog + * The platform driver (like drivers/watchdog/sbsa_gwdt.c)can get device + * info below by matching this name. + */ + pdev = platform_device_register_simple("sbsa-gwdt", index, res, + ARRAY_SIZE(res)); + if (IS_ERR(pdev)) { + acpi_unregister_gsi(wd->timer_interrupt); + return PTR_ERR(pdev); + } + + return 0; +} + +static int __init gtdt_platform_timer_parse(struct acpi_table_header *table) +{ + struct acpi_gtdt_header *header; + struct acpi_table_gtdt *gtdt; + void *gtdt_subtable; + int i, gwdt_index; + int ret = 0; + + if (table->revision < 2) { + pr_warn("GTDT: Revision:%d doesn't support Platform Timers.\n", + table->revision); + return 0; + } + + gtdt = container_of(table, struct acpi_table_gtdt, header); + if (!gtdt->platform_timer_count) { + pr_info("GTDT: No Platform Timer structures.\n"); + return 0; + } + + gtdt_subtable = (void *)gtdt + gtdt->platform_timer_offset; + + for (i = 0, gwdt_index = 0; i < gtdt->platform_timer_count; i++) { + if (gtdt_subtable > (void *)table + table->length) { + pr_err("GTDT: subtable pointer overflows, bad table\n"); + return -EINVAL; + } + header = (struct acpi_gtdt_header *)gtdt_subtable; + if (header->type == ACPI_GTDT_TYPE_WATCHDOG) { + ret = gtdt_import_sbsa_gwdt(gtdt_subtable, gwdt_index); + if (ret) + pr_err("GTDT: failed to import subtable %d\n", + i); + else + gwdt_index++; + } + gtdt_subtable += header->length; + } + + return ret; +} + +static int __init gtdt_platform_timer_init(void) +{ + if (acpi_disabled) + return 0; + + return acpi_table_parse(ACPI_SIG_GTDT, gtdt_platform_timer_parse); +} + +device_initcall(gtdt_platform_timer_init); |