diff options
author | Graeme Gregory <graeme.gregory@linaro.org> | 2016-01-20 14:29:27 (GMT) |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-02-16 18:58:25 (GMT) |
commit | 6ce2e188a6ae339340d9bbf5bb0b81db20454353 (patch) | |
tree | 52074e1abb79e6c9a5c5780404894e01bc129a33 /drivers/acpi | |
parent | 3b95bd160547f56a68aeb972c33ae9511e7a8380 (diff) | |
download | linux-6ce2e188a6ae339340d9bbf5bb0b81db20454353.tar.xz |
ACPI / scan: AMBA bus probing support
On ARM64 some devices use the AMBA device and not the platform bus for
probing so add support for this. Uses a dummy clock for apb_pclk as ACPI
does not have a suitable clock representation and to keep the core
AMBA bus code unchanged between probing methods.
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org>
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r-- | drivers/acpi/Makefile | 1 | ||||
-rw-r--r-- | drivers/acpi/acpi_amba.c | 122 | ||||
-rw-r--r-- | drivers/acpi/internal.h | 5 | ||||
-rw-r--r-- | drivers/acpi/scan.c | 1 |
4 files changed, 129 insertions, 0 deletions
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index cb648a4..edeb2d1 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -43,6 +43,7 @@ acpi-y += pci_root.o pci_link.o pci_irq.o acpi-y += acpi_lpss.o acpi_apd.o acpi-y += acpi_platform.o acpi-y += acpi_pnp.o +acpi-$(CONFIG_ARM_AMBA) += acpi_amba.o acpi-y += int340x_thermal.o acpi-y += power.o acpi-y += event.o diff --git a/drivers/acpi/acpi_amba.c b/drivers/acpi/acpi_amba.c new file mode 100644 index 0000000..2a61b54 --- /dev/null +++ b/drivers/acpi/acpi_amba.c @@ -0,0 +1,122 @@ + +/* + * ACPI support for platform bus type. + * + * Copyright (C) 2015, Linaro Ltd + * Author: Graeme Gregory <graeme.gregory@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/amba/bus.h> +#include <linux/clkdev.h> +#include <linux/clk-provider.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/ioport.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#include "internal.h" + +static const struct acpi_device_id amba_id_list[] = { + {"ARMH0061", 0}, /* PL061 GPIO Device */ + {"", 0}, +}; + +static void amba_register_dummy_clk(void) +{ + static struct clk *amba_dummy_clk; + + /* If clock already registered */ + if (amba_dummy_clk) + return; + + amba_dummy_clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, + CLK_IS_ROOT, 0); + clk_register_clkdev(amba_dummy_clk, "apb_pclk", NULL); +} + +static int amba_handler_attach(struct acpi_device *adev, + const struct acpi_device_id *id) +{ + struct amba_device *dev; + struct resource_entry *rentry; + struct list_head resource_list; + bool address_found = false; + int irq_no = 0; + int ret; + + /* If the ACPI node already has a physical device attached, skip it. */ + if (adev->physical_node_count) + return 0; + + dev = amba_device_alloc(dev_name(&adev->dev), 0, 0); + if (!dev) { + dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n", + __func__); + return -ENOMEM; + } + + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL); + if (ret < 0) + goto err_free; + + list_for_each_entry(rentry, &resource_list, node) { + switch (resource_type(rentry->res)) { + case IORESOURCE_MEM: + if (!address_found) { + dev->res = *rentry->res; + address_found = true; + } + break; + case IORESOURCE_IRQ: + if (irq_no < AMBA_NR_IRQS) + dev->irq[irq_no++] = rentry->res->start; + break; + default: + dev_warn(&adev->dev, "Invalid resource\n"); + break; + } + } + + acpi_dev_free_resource_list(&resource_list); + + /* + * If the ACPI node has a parent and that parent has a physical device + * attached to it, that physical device should be the parent of + * the amba device we are about to create. + */ + if (adev->parent) + dev->dev.parent = acpi_get_first_physical_node(adev->parent); + + ACPI_COMPANION_SET(&dev->dev, adev); + + ret = amba_device_add(dev, &iomem_resource); + if (ret) { + dev_err(&adev->dev, "%s(): amba_device_add() failed (%d)\n", + __func__, ret); + goto err_free; + } + + return 1; + +err_free: + amba_device_put(dev); + return ret; +} + +static struct acpi_scan_handler amba_handler = { + .ids = amba_id_list, + .attach = amba_handler_attach, +}; + +void __init acpi_amba_init(void) +{ + amba_register_dummy_clk(); + acpi_scan_add_handler(&amba_handler); +} diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 8668891..9860df0 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -29,6 +29,11 @@ void acpi_processor_init(void); void acpi_platform_init(void); void acpi_pnp_init(void); void acpi_int340x_thermal_init(void); +#ifdef CONFIG_ARM_AMBA +void acpi_amba_init(void); +#else +static inline void acpi_amba_init(void) {} +#endif int acpi_sysfs_init(void); void acpi_container_init(void); void acpi_memory_hotplug_init(void); diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 407a376..5f28cf7 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1930,6 +1930,7 @@ int __init acpi_scan_init(void) acpi_memory_hotplug_init(); acpi_pnp_init(); acpi_int340x_thermal_init(); + acpi_amba_init(); acpi_scan_add_handler(&generic_device_handler); |