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/*
* AMBA Connector Resource for ACPI
*
* Copyright (C) 2013 Advanced Micro Devices, Inc.
*
* Author: Brandon Anderson <brandon.anderson@amd.com>
*
* 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.
*/
#ifdef CONFIG_ACPI
#include <linux/module.h>
#include <linux/amba/bus.h>
#include <linux/platform_device.h>
#include <linux/acpi.h>
#include <linux/clkdev.h>
#include <linux/amba/acpi.h>
struct acpi_amba_bus_info {
struct platform_device *pdev;
struct clk *clk;
char *clk_name;
};
static int acpi_amba_add_resource(struct acpi_resource *ares, void *data)
{
struct amba_device *dev = data;
struct resource r;
int irq_idx;
switch (ares->type) {
case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
if (!acpi_dev_resource_memory(ares, &dev->res))
pr_err("failed to map memory resource\n");
break;
case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
for (irq_idx = 0; irq_idx < AMBA_NR_IRQS; irq_idx++) {
if (acpi_dev_resource_interrupt(ares, irq_idx, &r))
dev->irq[irq_idx] = r.start;
else
break;
}
break;
case ACPI_RESOURCE_TYPE_END_TAG:
/* ignore the end tag */
break;
default:
/* log an error, but proceed with driver probe */
pr_err("unhandled acpi resource type= %d\n",
ares->type);
break;
}
return 1; /* Tell ACPI core that this resource has been handled */
}
static struct clk *acpi_amba_get_clk(acpi_handle handle, int index,
char **clk_name)
{
acpi_handle clk_handle;
struct acpi_device *adev, *clk_adev;
const char **clk_paths;
struct clk *clk = NULL;
int ret;
if (acpi_bus_get_device(handle, &adev)) {
pr_err("cannot get device from handle\n");
return NULL;
}
/* Get number of entries */
ret = acpi_dev_get_property_array_string(adev, "clocks", NULL, 0);
if ((ret < 0) || (index >= ret))
return NULL;
clk_paths = kzalloc(sizeof(*clk_paths) * ret, GFP_KERNEL);
/* look under the clock device for the clock that matches the entry */
ret = acpi_dev_get_property_array_string(adev, "clocks", clk_paths,
ret);
/* Locate the acpi_device from the device name */
acpi_get_handle(NULL, (acpi_string)clk_paths[index], &clk_handle);
if (!clk_handle)
goto error;
acpi_bus_get_device(clk_handle, &clk_adev);
if (!clk_adev)
goto error;
clk = clk_get_sys(dev_name(&clk_adev->dev), NULL);
error:
kfree(clk_paths);
return clk;
}
static void acpi_amba_register_clocks(struct acpi_device *adev,
struct clk *default_clk, const char *default_clk_name)
{
struct clk *clk;
int i;
char *clk_name;
for (i = 0;; i++) {
clk_name = NULL;
clk = acpi_amba_get_clk(ACPI_HANDLE(&adev->dev), i, &clk_name);
if (!clk)
break;
clk_register_clkdev(clk, clk_name, dev_name(&adev->dev));
kfree(clk_name);
}
if (default_clk) {
/* for amba_get_enable_pclk() ... */
clk_register_clkdev(default_clk, default_clk_name,
dev_name(&adev->dev));
/* for devm_clk_get() ... */
clk_register_clkdev(default_clk, NULL, dev_name(&adev->dev));
}
}
/* acpi_amba_add_device()
*
* ACPI equivalent to of_amba_device_create()
*/
static acpi_status acpi_amba_add_device(acpi_handle handle,
u32 lvl_not_used, void *data, void **not_used)
{
struct list_head resource_list;
struct acpi_device *adev;
struct amba_device *dev;
int ret;
struct acpi_amba_bus_info *bus_info = data;
struct platform_device *bus_pdev = bus_info->pdev;
if (acpi_bus_get_device(handle, &adev)) {
pr_err("%s: acpi_bus_get_device failed\n", __func__);
return AE_OK;
}
pr_debug("Creating amba device %s\n", dev_name(&adev->dev));
dev = amba_device_alloc(NULL, 0, 0);
if (!dev) {
pr_err("%s(): amba_device_alloc() failed for %s\n",
__func__, dev_name(&adev->dev));
return AE_CTRL_TERMINATE;
}
/* setup generic device info */
dev->dev.coherent_dma_mask = ~0;
dev->dev.parent = &bus_pdev->dev;
dev_set_name(&dev->dev, "%s", dev_name(&adev->dev));
/* setup amba-specific device info */
ACPI_COMPANION_SET(&dev->dev, adev);
ACPI_COMPANION_SET(&adev->dev, adev);
INIT_LIST_HEAD(&resource_list);
acpi_dev_get_resources(adev, &resource_list,
acpi_amba_add_resource, dev);
acpi_dev_free_resource_list(&resource_list);
/* Add clocks */
acpi_amba_register_clocks(adev, bus_info->clk, bus_info->clk_name);
/* Read AMBA hardware ID and add device to system. If a driver matching
* hardware ID has already been registered, bind this device to it.
* Otherwise, the platform subsystem will match up the hardware ID
* when the matching driver is registered.
*/
ret = amba_device_add(dev, &iomem_resource);
if (ret) {
pr_err("%s(): amba_device_add() failed (%d) for %s\n",
__func__, ret, dev_name(&adev->dev));
goto err_free;
}
return AE_OK;
err_free:
amba_device_put(dev);
return AE_OK; /* don't prevent other devices from being probed */
}
static int acpi_amba_bus_probe(struct platform_device *pdev)
{
struct acpi_amba_bus_info bus_info;
bus_info.clk_name = NULL;
/* see if there's a top-level clock to use as default for sub-devices */
bus_info.clk = acpi_amba_get_clk(ACPI_HANDLE(&pdev->dev), 0,
&bus_info.clk_name);
/* probe each device */
bus_info.pdev = pdev;
acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_HANDLE(&pdev->dev), 1,
acpi_amba_add_device, NULL, &bus_info, NULL);
kfree(bus_info.clk_name);
return 0;
}
static const struct acpi_device_id amba_bus_acpi_match[] = {
{ "LNRO001A", 0 },
{ },
};
static struct platform_driver amba_bus_acpi_driver = {
.driver = {
.name = "amba-acpi",
.owner = THIS_MODULE,
.acpi_match_table = ACPI_PTR(amba_bus_acpi_match),
},
.probe = acpi_amba_bus_probe,
};
static int __init acpi_amba_bus_init(void)
{
return platform_driver_register(&amba_bus_acpi_driver);
}
postcore_initcall(acpi_amba_bus_init);
MODULE_AUTHOR("Brandon Anderson <brandon.anderson@amd.com>");
MODULE_DESCRIPTION("ACPI Connector Resource for AMBA bus");
MODULE_LICENSE("GPLv2");
MODULE_ALIAS("platform:amba-acpi");
#endif /* CONFIG_ACPI */
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