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>
This commit is contained in:
Graeme Gregory 2016-01-20 20:29:27 +06:00 committed by Rafael J. Wysocki
parent 3b95bd1605
commit 6ce2e188a6
4 changed files with 129 additions and 0 deletions

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@ -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

122
drivers/acpi/acpi_amba.c Normal file
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@ -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);
}

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@ -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);

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@ -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);