[PATCH v3 2/2] hwmon: Allow to compile dell-smm-hwmon driver without /proc/i8k

From: Pali RohÃr
Date: Thu May 14 2015 - 07:17:26 EST

This patch splits CONFIG_I8K compile option to SENSORS_DELL_SMM and CONFIG_I8K.
Option SENSORS_DELL_SMM is now used to enable compilation of dell-smm-hwmon
driver and old CONFIG_I8K option to enable /proc/i8k interface in driver.

So this change allows to compile dell-smm-hwmon driver without legacy /proc/i8k
interface which is needed only for old Dell Inspirion models or for userspace
i8kutils package.

For backward compatibility when CONFIG_I8K is enabled then also SENSORS_DELL_SMM
is enabled and so driver dell-smm-hwmon (with /proc/i8k) is compiled.

Signed-off-by: Pali RohÃr <pali.rohar@xxxxxxxxx>
---
changes since v2:
- removed depends on DMI
---
arch/x86/Kconfig | 25 +++----
drivers/hwmon/Kconfig | 11 +++
drivers/hwmon/Makefile | 2 +-
drivers/hwmon/dell-smm-hwmon.c | 150 ++++++++++++++++++++++------------------
4 files changed, 106 insertions(+), 82 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 226d569..7b756b3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1055,24 +1055,19 @@ config TOSHIBA
Say N otherwise.

config I8K
- tristate "Dell laptop support"
+ tristate "Dell i8k legacy laptop support"
select HWMON
+ select SENSORS_DELL_SMM
---help---
- This adds a driver to safely access the System Management Mode
- of the CPU on the Dell Inspiron 8000. The System Management Mode
- is used to read cpu temperature and cooling fan status and to
- control the fans on the I8K portables.
+ This option enables legacy /proc/i8k userspace interface in hwmon
+ dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
+ temperature and allows controlling fan speeds of Dell laptops via
+ System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
+ it reports also power and hotkey status. For fan speed control is
+ needed userspace package i8kutils.

- This driver has been tested only on the Inspiron 8000 but it may
- also work with other Dell laptops. You can force loading on other
- models by passing the parameter `force=1' to the module. Use at
- your own risk.
-
- For information on utilities to make use of this driver see the
- I8K Linux utilities web site at:
- <http://people.debian.org/~dz/i8k/>
-
- Say Y if you intend to run this kernel on a Dell Inspiron 8000.
+ Say Y if you intend to run this kernel on old Dell laptops or want to
+ use userspace package i8kutils.
Say N otherwise.

config X86_REBOOTFIXUPS
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 25d9e72..bc9d90b1 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -371,6 +371,17 @@ config SENSORS_DS1621
This driver can also be built as a module. If so, the module
will be called ds1621.

+config SENSORS_DELL_SMM
+ tristate "Dell laptop SMM BIOS hwmon driver"
+ depends on X86
+ help
+ This hwmon driver adds support for reporting temperature of different
+ sensors and controls the fans on Dell laptops via System Management
+ Mode provided by Dell BIOS.
+
+ When option I8K is also enabled this driver provides legacy /proc/i8k
+ userspace interface for i8kutils package.
+
config SENSORS_DA9052_ADC
tristate "Dialog DA9052/DA9053 ADC"
depends on PMIC_DA9052
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 51533ac..6cacd0f 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_SENSORS_ATXP1) += atxp1.o
obj-$(CONFIG_SENSORS_CORETEMP) += coretemp.o
obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o
obj-$(CONFIG_SENSORS_DA9055)+= da9055-hwmon.o
+obj-$(CONFIG_SENSORS_DELL_SMM) += dell-smm-hwmon.o
obj-$(CONFIG_SENSORS_DME1737) += dme1737.o
obj-$(CONFIG_SENSORS_DS620) += ds620.o
obj-$(CONFIG_SENSORS_DS1621) += ds1621.o
@@ -156,7 +157,6 @@ obj-$(CONFIG_SENSORS_W83L785TS) += w83l785ts.o
obj-$(CONFIG_SENSORS_W83L786NG) += w83l786ng.o
obj-$(CONFIG_SENSORS_WM831X) += wm831x-hwmon.o
obj-$(CONFIG_SENSORS_WM8350) += wm8350-hwmon.o
-obj-$(CONFIG_I8K) += dell-smm-hwmon.o

obj-$(CONFIG_PMBUS) += pmbus/

diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
index 65d314b..2a80882 100644
--- a/drivers/hwmon/dell-smm-hwmon.c
+++ b/drivers/hwmon/dell-smm-hwmon.c
@@ -81,7 +81,7 @@ static uint i8k_fan_max = I8K_FAN_HIGH;

MODULE_AUTHOR("Massimo Dal Zotto (dz@xxxxxxxxxx)");
MODULE_AUTHOR("Pali RohÃr <pali.rohar@xxxxxxxxx>");
-MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
+MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("i8k");

@@ -93,6 +93,7 @@ static bool ignore_dmi;
module_param(ignore_dmi, bool, 0);
MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");

+#if IS_ENABLED(CONFIG_I8K)
static bool restricted;
module_param(restricted, bool, 0);
MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
@@ -100,6 +101,7 @@ MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
static bool power_status;
module_param(power_status, bool, 0600);
MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
+#endif

static uint fan_mult;
module_param(fan_mult, uint, 0);
@@ -109,18 +111,6 @@ static uint fan_max;
module_param(fan_max, uint, 0);
MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");

-static int i8k_open_fs(struct inode *inode, struct file *file);
-static long i8k_ioctl(struct file *, unsigned int, unsigned long);
-
-static const struct file_operations i8k_fops = {
- .owner = THIS_MODULE,
- .open = i8k_open_fs,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
- .unlocked_ioctl = i8k_ioctl,
-};
-
struct smm_regs {
unsigned int eax;
unsigned int ebx __packed;
@@ -221,45 +211,6 @@ out:
}

/*
- * Read the Fn key status.
- */
-static int i8k_get_fn_status(void)
-{
- struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
- int rc;
-
- rc = i8k_smm(&regs);
- if (rc < 0)
- return rc;
-
- switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
- case I8K_FN_UP:
- return I8K_VOL_UP;
- case I8K_FN_DOWN:
- return I8K_VOL_DOWN;
- case I8K_FN_MUTE:
- return I8K_VOL_MUTE;
- default:
- return 0;
- }
-}
-
-/*
- * Read the power status.
- */
-static int i8k_get_power_status(void)
-{
- struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
- int rc;
-
- rc = i8k_smm(&regs);
- if (rc < 0)
- return rc;
-
- return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
-}
-
-/*
* Read the fan status.
*/
static int i8k_get_fan_status(int fan)
@@ -378,6 +329,51 @@ static int i8k_get_dell_signature(int req_fn)
return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
}

+#if IS_ENABLED(CONFIG_I8K)
+
+/*
+ * Read the Fn key status.
+ */
+static int i8k_get_fn_status(void)
+{
+ struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
+ int rc;
+
+ rc = i8k_smm(&regs);
+ if (rc < 0)
+ return rc;
+
+ switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
+ case I8K_FN_UP:
+ return I8K_VOL_UP;
+ case I8K_FN_DOWN:
+ return I8K_VOL_DOWN;
+ case I8K_FN_MUTE:
+ return I8K_VOL_MUTE;
+ default:
+ return 0;
+ }
+}
+
+/*
+ * Read the power status.
+ */
+static int i8k_get_power_status(void)
+{
+ struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
+ int rc;
+
+ rc = i8k_smm(&regs);
+ if (rc < 0)
+ return rc;
+
+ return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
+}
+
+/*
+ * Procfs interface
+ */
+
static int
i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
{
@@ -528,6 +524,37 @@ static int i8k_open_fs(struct inode *inode, struct file *file)
return single_open(file, i8k_proc_show, NULL);
}

+static const struct file_operations i8k_fops = {
+ .owner = THIS_MODULE,
+ .open = i8k_open_fs,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+ .unlocked_ioctl = i8k_ioctl,
+};
+
+static void __init i8k_init_procfs(void)
+{
+ /* Register the proc entry */
+ proc_create("i8k", 0, NULL, &i8k_fops);
+}
+
+static void __exit i8k_exit_procfs(void)
+{
+ remove_proc_entry("i8k", NULL);
+}
+
+#else
+
+static inline void __init i8k_init_procfs(void)
+{
+}
+
+static inline void __exit i8k_exit_procfs(void)
+{
+}
+
+#endif

/*
* Hwmon interface
@@ -750,8 +777,8 @@ static int __init i8k_init_hwmon(void)
if (err >= 0)
i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;

- i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "i8k", NULL,
- i8k_groups);
+ i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "dell-smm",
+ NULL, i8k_groups);
if (IS_ERR(i8k_hwmon_dev)) {
err = PTR_ERR(i8k_hwmon_dev);
i8k_hwmon_dev = NULL;
@@ -976,33 +1003,24 @@ static int __init i8k_probe(void)

static int __init i8k_init(void)
{
- struct proc_dir_entry *proc_i8k;
int err;

/* Are we running on an supported laptop? */
if (i8k_probe())
return -ENODEV;

- /* Register the proc entry */
- proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
- if (!proc_i8k)
- return -ENOENT;
-
err = i8k_init_hwmon();
if (err)
- goto exit_remove_proc;
+ return err;

+ i8k_init_procfs();
return 0;
-
- exit_remove_proc:
- remove_proc_entry("i8k", NULL);
- return err;
}

static void __exit i8k_exit(void)
{
hwmon_device_unregister(i8k_hwmon_dev);
- remove_proc_entry("i8k", NULL);
+ i8k_exit_procfs();
}

module_init(i8k_init);
--
1.7.10.4

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