ACPI: thinkpad-acpi: use a separate platform device for hwmon and name it (v2)

Use a separate platform device and driver ("thinkpad_hwmon") to attach
hwmon attributes and class, and add a name attribute of "thinkpad" to
it, which defines the hwmon device name for libsensors4.

This makes thinkpad-acpi compatible with libsensors4 from lm-sensors, and
the platform driver and device split will make it much easier to separate
hwmon functionality into its own module later on.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Len Brown <len.brown@intel.com>

3 files changed, 91 insertions, 19 deletions

diff --git a/Documentation/thinkpad-acpi.txt b/Documentation/thinkpad-acpi.txt
index 60953d6c919d..3b95bbacc775 100644
--- a/Documentation/thinkpad-acpi.txt
+++ b/Documentation/thinkpad-acpi.txt
@@ -105,10 +105,15 @@ The version of thinkpad-acpi's sysfs interface is exported by the driver
 as a driver attribute (see below).
 
 Sysfs driver attributes are on the driver's sysfs attribute space,
-for 2.6.20 this is /sys/bus/platform/drivers/thinkpad_acpi/.
+for 2.6.23 this is /sys/bus/platform/drivers/thinkpad_acpi/ and
+/sys/bus/platform/drivers/thinkpad_hwmon/
 
-Sysfs device attributes are on the driver's sysfs attribute space,
-for 2.6.20 this is /sys/devices/platform/thinkpad_acpi/.
+Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
+space, for 2.6.23 this is /sys/devices/platform/thinkpad_acpi/.
+
+Sysfs device attributes for the sensors and fan are on the
+thinkpad_hwmon device's sysfs attribute space, but you should locate it
+looking for a hwmon device with the name attribute of "thinkpad".
 
 Driver version
 --------------
@@ -766,7 +771,7 @@ Temperature sensors
 -------------------
 
 procfs: /proc/acpi/ibm/thermal
-sysfs device attributes: (hwmon) temp*_input
+sysfs device attributes: (hwmon "thinkpad") temp*_input
 
 Most ThinkPads include six or more separate temperature sensors but only
 expose the CPU temperature through the standard ACPI methods.  This
@@ -989,7 +994,9 @@ Fan control and monitoring: fan speed, fan enable/disable
 ---------------------------------------------------------
 
 procfs: /proc/acpi/ibm/fan
-sysfs device attributes: (hwmon) fan_input, pwm1, pwm1_enable
+sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
+                          pwm1_enable
+sysfs hwmon driver attributes: fan_watchdog
 
 NOTE NOTE NOTE: fan control operations are disabled by default for
 safety reasons.  To enable them, the module parameter "fan_control=1"
@@ -1131,7 +1138,7 @@ hwmon device attribute fan1_input:
         which can take up to two minutes.  May return rubbish on older
         ThinkPads.
 
-driver attribute fan_watchdog:
+hwmon driver attribute fan_watchdog:
         Fan safety watchdog timer interval, in seconds.  Minimum is
         1 second, maximum is 120 seconds.  0 disables the watchdog.
 
@@ -1233,3 +1240,9 @@ Sysfs interface changelog:
                 layer, the radio switch generates input event EV_RADIO,
                 and the driver enables hot key handling by default in
                 the firmware.
+
+0x020000:       ABI fix: added a separate hwmon platform device and
+                driver, which must be located by name (thinkpad)
+                and the hwmon class for libsensors4 (lm-sensors 3)
+                compatibility.  Moved all hwmon attributes to this
+                new platform device.
diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
index 0a33c6ee4508..d5fb93ed04f0 100644
--- a/drivers/misc/thinkpad_acpi.c
+++ b/drivers/misc/thinkpad_acpi.c
@@ -22,7 +22,7 @@
  */
 
 #define IBM_VERSION "0.16"
-#define TPACPI_SYSFS_VERSION 0x010000
+#define TPACPI_SYSFS_VERSION 0x020000
 
 /*
  *  Changelog:
@@ -526,6 +526,7 @@ static char *next_cmd(char **cmds)
  ****************************************************************************/
 
 static struct platform_device *tpacpi_pdev;
+static struct platform_device *tpacpi_sensors_pdev;
 static struct class_device *tpacpi_hwmon;
 static struct input_dev *tpacpi_inputdev;
 static struct mutex tpacpi_inputdev_send_mutex;
@@ -553,6 +554,12 @@ static struct platform_driver tpacpi_pdriver = {
         .resume = tpacpi_resume_handler,
 };
 
+static struct platform_driver tpacpi_hwmon_pdriver = {
+        .driver = {
+                .name = IBM_HWMON_DRVR_NAME,
+                .owner = THIS_MODULE,
+        },
+};
 
 /*************************************************************************
  * thinkpad-acpi driver attributes
@@ -2872,7 +2879,7 @@ static int __init thermal_init(struct ibm_init_struct *iibm)
 
         switch(thermal_read_mode) {
         case TPACPI_THERMAL_TPEC_16:
-                res = sysfs_create_group(&tpacpi_pdev->dev.kobj,
+                res = sysfs_create_group(&tpacpi_sensors_pdev->dev.kobj,
                                 &thermal_temp_input16_group);
                 if (res)
                         return res;
@@ -2880,7 +2887,7 @@ static int __init thermal_init(struct ibm_init_struct *iibm)
         case TPACPI_THERMAL_TPEC_8:
         case TPACPI_THERMAL_ACPI_TMP07:
         case TPACPI_THERMAL_ACPI_UPDT:
-                res = sysfs_create_group(&tpacpi_pdev->dev.kobj,
+                res = sysfs_create_group(&tpacpi_sensors_pdev->dev.kobj,
                                 &thermal_temp_input8_group);
                 if (res)
                         return res;
@@ -2897,13 +2904,13 @@ static void thermal_exit(void)
 {
         switch(thermal_read_mode) {
         case TPACPI_THERMAL_TPEC_16:
-                sysfs_remove_group(&tpacpi_pdev->dev.kobj,
+                sysfs_remove_group(&tpacpi_sensors_pdev->dev.kobj,
                                    &thermal_temp_input16_group);
                 break;
         case TPACPI_THERMAL_TPEC_8:
         case TPACPI_THERMAL_ACPI_TMP07:
         case TPACPI_THERMAL_ACPI_UPDT:
-                sysfs_remove_group(&tpacpi_pdev->dev.kobj,
+                sysfs_remove_group(&tpacpi_sensors_pdev->dev.kobj,
                                    &thermal_temp_input16_group);
                 break;
         case TPACPI_THERMAL_NONE:
@@ -3686,7 +3693,7 @@ static struct device_attribute dev_attr_fan_fan1_input =
         __ATTR(fan1_input, S_IRUGO,
                 fan_fan1_input_show, NULL);
 
-/* sysfs fan fan_watchdog (driver) ------------------------------------- */
+/* sysfs fan fan_watchdog (hwmon driver) ------------------------------- */
 static ssize_t fan_fan_watchdog_show(struct device_driver *drv,
                                      char *buf)
 {
@@ -3828,10 +3835,10 @@ static int __init fan_init(struct ibm_init_struct *iibm)
 
         if (fan_status_access_mode != TPACPI_FAN_NONE ||
             fan_control_access_mode != TPACPI_FAN_WR_NONE) {
-                rc = sysfs_create_group(&tpacpi_pdev->dev.kobj,
+                rc = sysfs_create_group(&tpacpi_sensors_pdev->dev.kobj,
                                          &fan_attr_group);
                 if (!(rc < 0))
-                        rc = driver_create_file(&tpacpi_pdriver.driver,
+                        rc = driver_create_file(&tpacpi_hwmon_pdriver.driver,
                                         &driver_attr_fan_watchdog);
                 if (rc < 0)
                         return rc;
@@ -3914,8 +3921,8 @@ static void fan_exit(void)
         vdbg_printk(TPACPI_DBG_EXIT, "cancelling any pending fan watchdog tasks\n");
 
         /* FIXME: can we really do this unconditionally? */
-        sysfs_remove_group(&tpacpi_pdev->dev.kobj, &fan_attr_group);
-        driver_remove_file(&tpacpi_pdriver.driver, &driver_attr_fan_watchdog);
+        sysfs_remove_group(&tpacpi_sensors_pdev->dev.kobj, &fan_attr_group);
+        driver_remove_file(&tpacpi_hwmon_pdriver.driver, &driver_attr_fan_watchdog);
 
         cancel_delayed_work(&fan_watchdog_task);
         flush_scheduled_work();
@@ -4366,6 +4373,19 @@ static struct ibm_struct fan_driver_data = {
  ****************************************************************************
  ****************************************************************************/
 
+/* sysfs name ---------------------------------------------------------- */
+static ssize_t thinkpad_acpi_pdev_name_show(struct device *dev,
+                           struct device_attribute *attr,
+                           char *buf)
+{
+        return snprintf(buf, PAGE_SIZE, "%s\n", IBM_NAME);
+}
+
+static struct device_attribute dev_attr_thinkpad_acpi_pdev_name =
+        __ATTR(name, S_IRUGO, thinkpad_acpi_pdev_name_show, NULL);
+
+/* --------------------------------------------------------------------- */
+
 /* /proc support */
 static struct proc_dir_entry *proc_dir;
 
@@ -4768,12 +4788,20 @@ static int __init thinkpad_acpi_module_init(void)
 
         ret = platform_driver_register(&tpacpi_pdriver);
         if (ret) {
-                printk(IBM_ERR "unable to register platform driver\n");
+                printk(IBM_ERR "unable to register main platform driver\n");
                 thinkpad_acpi_module_exit();
                 return ret;
         }
         tp_features.platform_drv_registered = 1;
 
+        ret = platform_driver_register(&tpacpi_hwmon_pdriver);
+        if (ret) {
+                printk(IBM_ERR "unable to register hwmon platform driver\n");
+                thinkpad_acpi_module_exit();
+                return ret;
+        }
+        tp_features.sensors_pdrv_registered = 1;
+
         ret = tpacpi_create_driver_attributes(&tpacpi_pdriver.driver);
         if (ret) {
                 printk(IBM_ERR "unable to create sysfs driver attributes\n");
@@ -4793,7 +4821,26 @@ static int __init thinkpad_acpi_module_init(void)
                 thinkpad_acpi_module_exit();
                 return ret;
         }
-        tpacpi_hwmon = hwmon_device_register(&tpacpi_pdev->dev);
+        tpacpi_sensors_pdev = platform_device_register_simple(
+                                                        IBM_HWMON_DRVR_NAME,
+                                                        -1, NULL, 0);
+        if (IS_ERR(tpacpi_sensors_pdev)) {
+                ret = PTR_ERR(tpacpi_sensors_pdev);
+                tpacpi_sensors_pdev = NULL;
+                printk(IBM_ERR "unable to register hwmon platform device\n");
+                thinkpad_acpi_module_exit();
+                return ret;
+        }
+        ret = device_create_file(&tpacpi_sensors_pdev->dev,
+                                 &dev_attr_thinkpad_acpi_pdev_name);
+        if (ret) {
+                printk(IBM_ERR
+                        "unable to create sysfs hwmon device attributes\n");
+                thinkpad_acpi_module_exit();
+                return ret;
+        }
+        tp_features.sensors_pdev_attrs_registered = 1;
+        tpacpi_hwmon = hwmon_device_register(&tpacpi_sensors_pdev->dev);
         if (IS_ERR(tpacpi_hwmon)) {
                 ret = PTR_ERR(tpacpi_hwmon);
                 tpacpi_hwmon = NULL;
@@ -4864,12 +4911,20 @@ static void thinkpad_acpi_module_exit(void)
         if (tpacpi_hwmon)
                 hwmon_device_unregister(tpacpi_hwmon);
 
+        if (tp_features.sensors_pdev_attrs_registered)
+                device_remove_file(&tpacpi_sensors_pdev->dev,
+                                   &dev_attr_thinkpad_acpi_pdev_name);
+        if (tpacpi_sensors_pdev)
+                platform_device_unregister(tpacpi_sensors_pdev);
         if (tpacpi_pdev)
                 platform_device_unregister(tpacpi_pdev);
 
         if (tp_features.platform_drv_attrs_registered)
                 tpacpi_remove_driver_attributes(&tpacpi_pdriver.driver);
 
+        if (tp_features.sensors_pdrv_registered)
+                platform_driver_unregister(&tpacpi_hwmon_pdriver);
+
         if (tp_features.platform_drv_registered)
                 platform_driver_unregister(&tpacpi_pdriver);
 
diff --git a/drivers/misc/thinkpad_acpi.h b/drivers/misc/thinkpad_acpi.h
index fa64dedd26d9..791b8ca4bca5 100644
--- a/drivers/misc/thinkpad_acpi.h
+++ b/drivers/misc/thinkpad_acpi.h
@@ -58,13 +58,14 @@
 
 #define IBM_NAME "thinkpad"
 #define IBM_DESC "ThinkPad ACPI Extras"
-#define IBM_FILE "thinkpad_acpi"
+#define IBM_FILE IBM_NAME "_acpi"
 #define IBM_URL "http://ibm-acpi.sf.net/"
 #define IBM_MAIL "ibm-acpi-devel@lists.sourceforge.net"
 
 #define IBM_PROC_DIR "ibm"
 #define IBM_ACPI_EVENT_PREFIX "ibm"
 #define IBM_DRVR_NAME IBM_FILE
+#define IBM_HWMON_DRVR_NAME IBM_NAME "_hwmon"
 
 #define IBM_LOG IBM_FILE ": "
 #define IBM_ERR    KERN_ERR    IBM_LOG
@@ -171,6 +172,7 @@ static int parse_strtoul(const char *buf, unsigned long max,
 
 /* Device model */
 static struct platform_device *tpacpi_pdev;
+static struct platform_device *tpacpi_sensors_pdev;
 static struct class_device *tpacpi_hwmon;
 static struct platform_driver tpacpi_pdriver;
 static struct input_dev *tpacpi_inputdev;
@@ -249,6 +251,8 @@ static struct {
         u32 input_device_registered:1;
         u32 platform_drv_registered:1;
         u32 platform_drv_attrs_registered:1;
+        u32 sensors_pdrv_registered:1;
+        u32 sensors_pdev_attrs_registered:1;
 } tp_features;
 
 struct thinkpad_id_data {