mirror of https://gitee.com/openkylin/linux.git
100 lines
2.5 KiB
C
100 lines
2.5 KiB
C
/*
|
|
* Intel Low Power Subsystem clocks.
|
|
*
|
|
* Copyright (C) 2013, Intel Corporation
|
|
* Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
|
|
* Heikki Krogerus <heikki.krogerus@linux.intel.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.
|
|
*/
|
|
|
|
#include <linux/acpi.h>
|
|
#include <linux/clk.h>
|
|
#include <linux/clk-provider.h>
|
|
#include <linux/err.h>
|
|
#include <linux/io.h>
|
|
#include <linux/module.h>
|
|
|
|
static int clk_lpss_is_mmio_resource(struct acpi_resource *res, void *data)
|
|
{
|
|
struct resource r;
|
|
return !acpi_dev_resource_memory(res, &r);
|
|
}
|
|
|
|
static acpi_status clk_lpss_find_mmio(acpi_handle handle, u32 level,
|
|
void *data, void **retval)
|
|
{
|
|
struct resource_list_entry *rentry;
|
|
struct list_head resource_list;
|
|
struct acpi_device *adev;
|
|
const char *uid = data;
|
|
int ret;
|
|
|
|
if (acpi_bus_get_device(handle, &adev))
|
|
return AE_OK;
|
|
|
|
if (uid) {
|
|
if (!adev->pnp.unique_id)
|
|
return AE_OK;
|
|
if (strcmp(uid, adev->pnp.unique_id))
|
|
return AE_OK;
|
|
}
|
|
|
|
INIT_LIST_HEAD(&resource_list);
|
|
ret = acpi_dev_get_resources(adev, &resource_list,
|
|
clk_lpss_is_mmio_resource, NULL);
|
|
if (ret < 0)
|
|
return AE_NO_MEMORY;
|
|
|
|
list_for_each_entry(rentry, &resource_list, node)
|
|
if (resource_type(&rentry->res) == IORESOURCE_MEM) {
|
|
*(struct resource *)retval = rentry->res;
|
|
break;
|
|
}
|
|
|
|
acpi_dev_free_resource_list(&resource_list);
|
|
return AE_OK;
|
|
}
|
|
|
|
/**
|
|
* clk_register_lpss_gate - register LPSS clock gate
|
|
* @name: name of this clock gate
|
|
* @parent_name: parent clock name
|
|
* @hid: ACPI _HID of the device
|
|
* @uid: ACPI _UID of the device (optional)
|
|
* @offset: LPSS PRV_CLOCK_PARAMS offset
|
|
*
|
|
* Creates and registers LPSS clock gate.
|
|
*/
|
|
struct clk *clk_register_lpss_gate(const char *name, const char *parent_name,
|
|
const char *hid, const char *uid,
|
|
unsigned offset)
|
|
{
|
|
struct resource res = { };
|
|
void __iomem *mmio_base;
|
|
acpi_status status;
|
|
struct clk *clk;
|
|
|
|
/*
|
|
* First try to look the device and its mmio resource from the
|
|
* ACPI namespace.
|
|
*/
|
|
status = acpi_get_devices(hid, clk_lpss_find_mmio, (void *)uid,
|
|
(void **)&res);
|
|
if (ACPI_FAILURE(status) || !res.start)
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
mmio_base = ioremap(res.start, resource_size(&res));
|
|
if (!mmio_base)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
clk = clk_register_gate(NULL, name, parent_name, 0, mmio_base + offset,
|
|
0, 0, NULL);
|
|
if (IS_ERR(clk))
|
|
iounmap(mmio_base);
|
|
|
|
return clk;
|
|
}
|