linux/drivers/acpi/acpi_lpss.c
Rafael J. Wysocki b9e95fc65e ACPI / LPSS: Power up LPSS devices during enumeration
Commit 7cd8407 (ACPI / PM: Do not execute _PS0 for devices without
_PSC during initialization) introduced a regression on some systems
with Intel Lynxpoint Low-Power Subsystem (LPSS) where some devices
need to be powered up during initialization, but their device objects
in the ACPI namespace have _PS0 and _PS3 only (without _PSC or power
resources).

To work around this problem, make the ACPI LPSS driver power up
devices it knows about by using a new helper function
acpi_device_fix_up_power() that does all of the necessary
sanity checks and calls acpi_dev_pm_explicit_set() to put the
device into D0.

Reported-and-tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-20 00:49:06 +02:00

320 lines
7.7 KiB
C

/*
* ACPI support for Intel Lynxpoint LPSS.
*
* Copyright (C) 2013, Intel Corporation
* Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
* Rafael J. Wysocki <rafael.j.wysocki@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/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/platform_data/clk-lpss.h>
#include <linux/pm_runtime.h>
#include "internal.h"
ACPI_MODULE_NAME("acpi_lpss");
#define LPSS_CLK_SIZE 0x04
#define LPSS_LTR_SIZE 0x18
/* Offsets relative to LPSS_PRIVATE_OFFSET */
#define LPSS_GENERAL 0x08
#define LPSS_GENERAL_LTR_MODE_SW BIT(2)
#define LPSS_SW_LTR 0x10
#define LPSS_AUTO_LTR 0x14
struct lpss_device_desc {
bool clk_required;
const char *clkdev_name;
bool ltr_required;
unsigned int prv_offset;
};
static struct lpss_device_desc lpss_dma_desc = {
.clk_required = true,
.clkdev_name = "hclk",
};
struct lpss_private_data {
void __iomem *mmio_base;
resource_size_t mmio_size;
struct clk *clk;
const struct lpss_device_desc *dev_desc;
};
static struct lpss_device_desc lpt_dev_desc = {
.clk_required = true,
.prv_offset = 0x800,
.ltr_required = true,
};
static struct lpss_device_desc lpt_sdio_dev_desc = {
.prv_offset = 0x1000,
.ltr_required = true,
};
static const struct acpi_device_id acpi_lpss_device_ids[] = {
/* Generic LPSS devices */
{ "INTL9C60", (unsigned long)&lpss_dma_desc },
/* Lynxpoint LPSS devices */
{ "INT33C0", (unsigned long)&lpt_dev_desc },
{ "INT33C1", (unsigned long)&lpt_dev_desc },
{ "INT33C2", (unsigned long)&lpt_dev_desc },
{ "INT33C3", (unsigned long)&lpt_dev_desc },
{ "INT33C4", (unsigned long)&lpt_dev_desc },
{ "INT33C5", (unsigned long)&lpt_dev_desc },
{ "INT33C6", (unsigned long)&lpt_sdio_dev_desc },
{ "INT33C7", },
{ }
};
static int is_memory(struct acpi_resource *res, void *not_used)
{
struct resource r;
return !acpi_dev_resource_memory(res, &r);
}
/* LPSS main clock device. */
static struct platform_device *lpss_clk_dev;
static inline void lpt_register_clock_device(void)
{
lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
}
static int register_device_clock(struct acpi_device *adev,
struct lpss_private_data *pdata)
{
const struct lpss_device_desc *dev_desc = pdata->dev_desc;
struct lpss_clk_data *clk_data;
if (!lpss_clk_dev)
lpt_register_clock_device();
clk_data = platform_get_drvdata(lpss_clk_dev);
if (!clk_data)
return -ENODEV;
if (dev_desc->clkdev_name) {
clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
dev_name(&adev->dev));
return 0;
}
if (!pdata->mmio_base
|| pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
return -ENODATA;
pdata->clk = clk_register_gate(NULL, dev_name(&adev->dev),
clk_data->name, 0,
pdata->mmio_base + dev_desc->prv_offset,
0, 0, NULL);
if (IS_ERR(pdata->clk))
return PTR_ERR(pdata->clk);
clk_register_clkdev(pdata->clk, NULL, dev_name(&adev->dev));
return 0;
}
static int acpi_lpss_create_device(struct acpi_device *adev,
const struct acpi_device_id *id)
{
struct lpss_device_desc *dev_desc;
struct lpss_private_data *pdata;
struct resource_list_entry *rentry;
struct list_head resource_list;
int ret;
dev_desc = (struct lpss_device_desc *)id->driver_data;
if (!dev_desc)
return acpi_create_platform_device(adev, id);
pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
INIT_LIST_HEAD(&resource_list);
ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
if (ret < 0)
goto err_out;
list_for_each_entry(rentry, &resource_list, node)
if (resource_type(&rentry->res) == IORESOURCE_MEM) {
pdata->mmio_size = resource_size(&rentry->res);
pdata->mmio_base = ioremap(rentry->res.start,
pdata->mmio_size);
pdata->dev_desc = dev_desc;
break;
}
acpi_dev_free_resource_list(&resource_list);
if (dev_desc->clk_required) {
ret = register_device_clock(adev, pdata);
if (ret) {
/* Skip the device, but continue the namespace scan. */
ret = 0;
goto err_out;
}
}
/*
* This works around a known issue in ACPI tables where LPSS devices
* have _PS0 and _PS3 without _PSC (and no power resources), so
* acpi_bus_init_power() will assume that the BIOS has put them into D0.
*/
ret = acpi_device_fix_up_power(adev);
if (ret) {
/* Skip the device, but continue the namespace scan. */
ret = 0;
goto err_out;
}
adev->driver_data = pdata;
ret = acpi_create_platform_device(adev, id);
if (ret > 0)
return ret;
adev->driver_data = NULL;
err_out:
kfree(pdata);
return ret;
}
static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
{
struct acpi_device *adev;
struct lpss_private_data *pdata;
unsigned long flags;
int ret;
ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
if (WARN_ON(ret))
return ret;
spin_lock_irqsave(&dev->power.lock, flags);
if (pm_runtime_suspended(dev)) {
ret = -EAGAIN;
goto out;
}
pdata = acpi_driver_data(adev);
if (WARN_ON(!pdata || !pdata->mmio_base)) {
ret = -ENODEV;
goto out;
}
*val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
out:
spin_unlock_irqrestore(&dev->power.lock, flags);
return ret;
}
static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
u32 ltr_value = 0;
unsigned int reg;
int ret;
reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
ret = lpss_reg_read(dev, reg, &ltr_value);
if (ret)
return ret;
return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
}
static ssize_t lpss_ltr_mode_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
u32 ltr_mode = 0;
char *outstr;
int ret;
ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
if (ret)
return ret;
outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
return sprintf(buf, "%s\n", outstr);
}
static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
static struct attribute *lpss_attrs[] = {
&dev_attr_auto_ltr.attr,
&dev_attr_sw_ltr.attr,
&dev_attr_ltr_mode.attr,
NULL,
};
static struct attribute_group lpss_attr_group = {
.attrs = lpss_attrs,
.name = "lpss_ltr",
};
static int acpi_lpss_platform_notify(struct notifier_block *nb,
unsigned long action, void *data)
{
struct platform_device *pdev = to_platform_device(data);
struct lpss_private_data *pdata;
struct acpi_device *adev;
const struct acpi_device_id *id;
int ret = 0;
id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
if (!id || !id->driver_data)
return 0;
if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
return 0;
pdata = acpi_driver_data(adev);
if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
return 0;
if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
return 0;
}
if (action == BUS_NOTIFY_ADD_DEVICE)
ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
else if (action == BUS_NOTIFY_DEL_DEVICE)
sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
return ret;
}
static struct notifier_block acpi_lpss_nb = {
.notifier_call = acpi_lpss_platform_notify,
};
static struct acpi_scan_handler lpss_handler = {
.ids = acpi_lpss_device_ids,
.attach = acpi_lpss_create_device,
};
void __init acpi_lpss_init(void)
{
if (!lpt_clk_init()) {
bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
acpi_scan_add_handler(&lpss_handler);
}
}