kernel_optimize_test/drivers/leds/leds-ss4200.c
Johan Hovold 67bd8eb07e leds: ss4200: fix attribute-creation race
Use the attribute groups of the led-class to create the blink attribute
during probe in order to avoid racing with userspace.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-06-25 15:34:24 -07:00

561 lines
14 KiB
C

/*
* SS4200-E Hardware API
* Copyright (c) 2009, Intel Corporation.
* Copyright IBM Corporation, 2009
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
* Author: Dave Hansen <dave@sr71.net>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/dmi.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/types.h>
#include <linux/uaccess.h>
MODULE_AUTHOR("Rodney Girod <rgirod@confocus.com>, Dave Hansen <dave@sr71.net>");
MODULE_DESCRIPTION("Intel NAS/Home Server ICH7 GPIO Driver");
MODULE_LICENSE("GPL");
/*
* ICH7 LPC/GPIO PCI Config register offsets
*/
#define PMBASE 0x040
#define GPIO_BASE 0x048
#define GPIO_CTRL 0x04c
#define GPIO_EN 0x010
/*
* The ICH7 GPIO register block is 64 bytes in size.
*/
#define ICH7_GPIO_SIZE 64
/*
* Define register offsets within the ICH7 register block.
*/
#define GPIO_USE_SEL 0x000
#define GP_IO_SEL 0x004
#define GP_LVL 0x00c
#define GPO_BLINK 0x018
#define GPI_INV 0x030
#define GPIO_USE_SEL2 0x034
#define GP_IO_SEL2 0x038
#define GP_LVL2 0x03c
/*
* PCI ID of the Intel ICH7 LPC Device within which the GPIO block lives.
*/
static const struct pci_device_id ich7_lpc_pci_id[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_0) },
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_1) },
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_30) },
{ } /* NULL entry */
};
MODULE_DEVICE_TABLE(pci, ich7_lpc_pci_id);
static int __init ss4200_led_dmi_callback(const struct dmi_system_id *id)
{
pr_info("detected '%s'\n", id->ident);
return 1;
}
static bool nodetect;
module_param_named(nodetect, nodetect, bool, 0);
MODULE_PARM_DESC(nodetect, "Skip DMI-based hardware detection");
/*
* struct nas_led_whitelist - List of known good models
*
* Contains the known good models this driver is compatible with.
* When adding a new model try to be as strict as possible. This
* makes it possible to keep the false positives (the model is
* detected as working, but in reality it is not) as low as
* possible.
*/
static struct dmi_system_id nas_led_whitelist[] __initdata = {
{
.callback = ss4200_led_dmi_callback,
.ident = "Intel SS4200-E",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Intel"),
DMI_MATCH(DMI_PRODUCT_NAME, "SS4200-E"),
DMI_MATCH(DMI_PRODUCT_VERSION, "1.00.00")
}
},
{}
};
/*
* Base I/O address assigned to the Power Management register block
*/
static u32 g_pm_io_base;
/*
* Base I/O address assigned to the ICH7 GPIO register block
*/
static u32 nas_gpio_io_base;
/*
* When we successfully register a region, we are returned a resource.
* We use these to identify which regions we need to release on our way
* back out.
*/
static struct resource *gp_gpio_resource;
struct nasgpio_led {
char *name;
u32 gpio_bit;
struct led_classdev led_cdev;
};
/*
* gpio_bit(s) are the ICH7 GPIO bit assignments
*/
static struct nasgpio_led nasgpio_leds[] = {
{ .name = "hdd1:blue:sata", .gpio_bit = 0 },
{ .name = "hdd1:amber:sata", .gpio_bit = 1 },
{ .name = "hdd2:blue:sata", .gpio_bit = 2 },
{ .name = "hdd2:amber:sata", .gpio_bit = 3 },
{ .name = "hdd3:blue:sata", .gpio_bit = 4 },
{ .name = "hdd3:amber:sata", .gpio_bit = 5 },
{ .name = "hdd4:blue:sata", .gpio_bit = 6 },
{ .name = "hdd4:amber:sata", .gpio_bit = 7 },
{ .name = "power:blue:power", .gpio_bit = 27},
{ .name = "power:amber:power", .gpio_bit = 28},
};
#define NAS_RECOVERY 0x00000400 /* GPIO10 */
static struct nasgpio_led *
led_classdev_to_nasgpio_led(struct led_classdev *led_cdev)
{
return container_of(led_cdev, struct nasgpio_led, led_cdev);
}
static struct nasgpio_led *get_led_named(char *name)
{
int i;
for (i = 0; i < ARRAY_SIZE(nasgpio_leds); i++) {
if (strcmp(nasgpio_leds[i].name, name))
continue;
return &nasgpio_leds[i];
}
return NULL;
}
/*
* This protects access to the gpio ports.
*/
static DEFINE_SPINLOCK(nasgpio_gpio_lock);
/*
* There are two gpio ports, one for blinking and the other
* for power. @port tells us if we're doing blinking or
* power control.
*
* Caller must hold nasgpio_gpio_lock
*/
static void __nasgpio_led_set_attr(struct led_classdev *led_cdev,
u32 port, u32 value)
{
struct nasgpio_led *led = led_classdev_to_nasgpio_led(led_cdev);
u32 gpio_out;
gpio_out = inl(nas_gpio_io_base + port);
if (value)
gpio_out |= (1<<led->gpio_bit);
else
gpio_out &= ~(1<<led->gpio_bit);
outl(gpio_out, nas_gpio_io_base + port);
}
static void nasgpio_led_set_attr(struct led_classdev *led_cdev,
u32 port, u32 value)
{
spin_lock(&nasgpio_gpio_lock);
__nasgpio_led_set_attr(led_cdev, port, value);
spin_unlock(&nasgpio_gpio_lock);
}
static u32 nasgpio_led_get_attr(struct led_classdev *led_cdev, u32 port)
{
struct nasgpio_led *led = led_classdev_to_nasgpio_led(led_cdev);
u32 gpio_in;
spin_lock(&nasgpio_gpio_lock);
gpio_in = inl(nas_gpio_io_base + port);
spin_unlock(&nasgpio_gpio_lock);
if (gpio_in & (1<<led->gpio_bit))
return 1;
return 0;
}
/*
* There is actual brightness control in the hardware,
* but it is via smbus commands and not implemented
* in this driver.
*/
static void nasgpio_led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
u32 setting = 0;
if (brightness >= LED_HALF)
setting = 1;
/*
* Hold the lock across both operations. This ensures
* consistency so that both the "turn off blinking"
* and "turn light off" operations complete as a set.
*/
spin_lock(&nasgpio_gpio_lock);
/*
* LED class documentation asks that past blink state
* be disabled when brightness is turned to zero.
*/
if (brightness == 0)
__nasgpio_led_set_attr(led_cdev, GPO_BLINK, 0);
__nasgpio_led_set_attr(led_cdev, GP_LVL, setting);
spin_unlock(&nasgpio_gpio_lock);
}
static int nasgpio_led_set_blink(struct led_classdev *led_cdev,
unsigned long *delay_on,
unsigned long *delay_off)
{
u32 setting = 1;
if (!(*delay_on == 0 && *delay_off == 0) &&
!(*delay_on == 500 && *delay_off == 500))
return -EINVAL;
/*
* These are very approximate.
*/
*delay_on = 500;
*delay_off = 500;
nasgpio_led_set_attr(led_cdev, GPO_BLINK, setting);
return 0;
}
/*
* Initialize the ICH7 GPIO registers for NAS usage. The BIOS should have
* already taken care of this, but we will do so in a non destructive manner
* so that we have what we need whether the BIOS did it or not.
*/
static int ich7_gpio_init(struct device *dev)
{
int i;
u32 config_data = 0;
u32 all_nas_led = 0;
for (i = 0; i < ARRAY_SIZE(nasgpio_leds); i++)
all_nas_led |= (1<<nasgpio_leds[i].gpio_bit);
spin_lock(&nasgpio_gpio_lock);
/*
* We need to enable all of the GPIO lines used by the NAS box,
* so we will read the current Use Selection and add our usage
* to it. This should be benign with regard to the original
* BIOS configuration.
*/
config_data = inl(nas_gpio_io_base + GPIO_USE_SEL);
dev_dbg(dev, ": Data read from GPIO_USE_SEL = 0x%08x\n", config_data);
config_data |= all_nas_led + NAS_RECOVERY;
outl(config_data, nas_gpio_io_base + GPIO_USE_SEL);
config_data = inl(nas_gpio_io_base + GPIO_USE_SEL);
dev_dbg(dev, ": GPIO_USE_SEL = 0x%08x\n\n", config_data);
/*
* The LED GPIO outputs need to be configured for output, so we
* will ensure that all LED lines are cleared for output and the
* RECOVERY line ready for input. This too should be benign with
* regard to BIOS configuration.
*/
config_data = inl(nas_gpio_io_base + GP_IO_SEL);
dev_dbg(dev, ": Data read from GP_IO_SEL = 0x%08x\n",
config_data);
config_data &= ~all_nas_led;
config_data |= NAS_RECOVERY;
outl(config_data, nas_gpio_io_base + GP_IO_SEL);
config_data = inl(nas_gpio_io_base + GP_IO_SEL);
dev_dbg(dev, ": GP_IO_SEL = 0x%08x\n", config_data);
/*
* In our final system, the BIOS will initialize the state of all
* of the LEDs. For now, we turn them all off (or Low).
*/
config_data = inl(nas_gpio_io_base + GP_LVL);
dev_dbg(dev, ": Data read from GP_LVL = 0x%08x\n", config_data);
/*
* In our final system, the BIOS will initialize the blink state of all
* of the LEDs. For now, we turn blink off for all of them.
*/
config_data = inl(nas_gpio_io_base + GPO_BLINK);
dev_dbg(dev, ": Data read from GPO_BLINK = 0x%08x\n", config_data);
/*
* At this moment, I am unsure if anything needs to happen with GPI_INV
*/
config_data = inl(nas_gpio_io_base + GPI_INV);
dev_dbg(dev, ": Data read from GPI_INV = 0x%08x\n", config_data);
spin_unlock(&nasgpio_gpio_lock);
return 0;
}
static void ich7_lpc_cleanup(struct device *dev)
{
/*
* If we were given exclusive use of the GPIO
* I/O Address range, we must return it.
*/
if (gp_gpio_resource) {
dev_dbg(dev, ": Releasing GPIO I/O addresses\n");
release_region(nas_gpio_io_base, ICH7_GPIO_SIZE);
gp_gpio_resource = NULL;
}
}
/*
* The OS has determined that the LPC of the Intel ICH7 Southbridge is present
* so we can retrive the required operational information and prepare the GPIO.
*/
static struct pci_dev *nas_gpio_pci_dev;
static int ich7_lpc_probe(struct pci_dev *dev,
const struct pci_device_id *id)
{
int status;
u32 gc = 0;
status = pci_enable_device(dev);
if (status) {
dev_err(&dev->dev, "pci_enable_device failed\n");
return -EIO;
}
nas_gpio_pci_dev = dev;
status = pci_read_config_dword(dev, PMBASE, &g_pm_io_base);
if (status)
goto out;
g_pm_io_base &= 0x00000ff80;
status = pci_read_config_dword(dev, GPIO_CTRL, &gc);
if (!(GPIO_EN & gc)) {
status = -EEXIST;
dev_info(&dev->dev,
"ERROR: The LPC GPIO Block has not been enabled.\n");
goto out;
}
status = pci_read_config_dword(dev, GPIO_BASE, &nas_gpio_io_base);
if (0 > status) {
dev_info(&dev->dev, "Unable to read GPIOBASE.\n");
goto out;
}
dev_dbg(&dev->dev, ": GPIOBASE = 0x%08x\n", nas_gpio_io_base);
nas_gpio_io_base &= 0x00000ffc0;
/*
* Insure that we have exclusive access to the GPIO I/O address range.
*/
gp_gpio_resource = request_region(nas_gpio_io_base, ICH7_GPIO_SIZE,
KBUILD_MODNAME);
if (NULL == gp_gpio_resource) {
dev_info(&dev->dev,
"ERROR Unable to register GPIO I/O addresses.\n");
status = -1;
goto out;
}
/*
* Initialize the GPIO for NAS/Home Server Use
*/
ich7_gpio_init(&dev->dev);
out:
if (status) {
ich7_lpc_cleanup(&dev->dev);
pci_disable_device(dev);
}
return status;
}
static void ich7_lpc_remove(struct pci_dev *dev)
{
ich7_lpc_cleanup(&dev->dev);
pci_disable_device(dev);
}
/*
* pci_driver structure passed to the PCI modules
*/
static struct pci_driver nas_gpio_pci_driver = {
.name = KBUILD_MODNAME,
.id_table = ich7_lpc_pci_id,
.probe = ich7_lpc_probe,
.remove = ich7_lpc_remove,
};
static struct led_classdev *get_classdev_for_led_nr(int nr)
{
struct nasgpio_led *nas_led = &nasgpio_leds[nr];
struct led_classdev *led = &nas_led->led_cdev;
return led;
}
static void set_power_light_amber_noblink(void)
{
struct nasgpio_led *amber = get_led_named("power:amber:power");
struct nasgpio_led *blue = get_led_named("power:blue:power");
if (!amber || !blue)
return;
/*
* LED_OFF implies disabling future blinking
*/
pr_debug("setting blue off and amber on\n");
nasgpio_led_set_brightness(&blue->led_cdev, LED_OFF);
nasgpio_led_set_brightness(&amber->led_cdev, LED_FULL);
}
static ssize_t nas_led_blink_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led = dev_get_drvdata(dev);
int blinking = 0;
if (nasgpio_led_get_attr(led, GPO_BLINK))
blinking = 1;
return sprintf(buf, "%u\n", blinking);
}
static ssize_t nas_led_blink_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
int ret;
struct led_classdev *led = dev_get_drvdata(dev);
unsigned long blink_state;
ret = kstrtoul(buf, 10, &blink_state);
if (ret)
return ret;
nasgpio_led_set_attr(led, GPO_BLINK, blink_state);
return size;
}
static DEVICE_ATTR(blink, 0644, nas_led_blink_show, nas_led_blink_store);
static struct attribute *nasgpio_led_attrs[] = {
&dev_attr_blink.attr,
NULL
};
ATTRIBUTE_GROUPS(nasgpio_led);
static int register_nasgpio_led(int led_nr)
{
int ret;
struct nasgpio_led *nas_led = &nasgpio_leds[led_nr];
struct led_classdev *led = get_classdev_for_led_nr(led_nr);
led->name = nas_led->name;
led->brightness = LED_OFF;
if (nasgpio_led_get_attr(led, GP_LVL))
led->brightness = LED_FULL;
led->brightness_set = nasgpio_led_set_brightness;
led->blink_set = nasgpio_led_set_blink;
led->groups = nasgpio_led_groups;
ret = led_classdev_register(&nas_gpio_pci_dev->dev, led);
if (ret)
return ret;
return 0;
}
static void unregister_nasgpio_led(int led_nr)
{
struct led_classdev *led = get_classdev_for_led_nr(led_nr);
led_classdev_unregister(led);
}
/*
* module load/initialization
*/
static int __init nas_gpio_init(void)
{
int i;
int ret = 0;
int nr_devices = 0;
nr_devices = dmi_check_system(nas_led_whitelist);
if (nodetect) {
pr_info("skipping hardware autodetection\n");
pr_info("Please send 'dmidecode' output to dave@sr71.net\n");
nr_devices++;
}
if (nr_devices <= 0) {
pr_info("no LED devices found\n");
return -ENODEV;
}
pr_info("registering PCI driver\n");
ret = pci_register_driver(&nas_gpio_pci_driver);
if (ret)
return ret;
for (i = 0; i < ARRAY_SIZE(nasgpio_leds); i++) {
ret = register_nasgpio_led(i);
if (ret)
goto out_err;
}
/*
* When the system powers on, the BIOS leaves the power
* light blue and blinking. This will turn it solid
* amber once the driver is loaded.
*/
set_power_light_amber_noblink();
return 0;
out_err:
for (i--; i >= 0; i--)
unregister_nasgpio_led(i);
pci_unregister_driver(&nas_gpio_pci_driver);
return ret;
}
/*
* module unload
*/
static void __exit nas_gpio_exit(void)
{
int i;
pr_info("Unregistering driver\n");
for (i = 0; i < ARRAY_SIZE(nasgpio_leds); i++)
unregister_nasgpio_led(i);
pci_unregister_driver(&nas_gpio_pci_driver);
}
module_init(nas_gpio_init);
module_exit(nas_gpio_exit);