lis3: update documentation and comments

Most of the documentation and comments were written when the driver was
only supporting one type of chip, only via ACPI/HP. Update the info to
the much clearer understanding that we have now.

Signed-off-by: Éric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 38 insertions, 32 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 9e640c62ebd9..95ccbe377f9c 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1046,25 +1046,27 @@ config SENSORS_ATK0110
           will be called asus_atk0110.
 
 config SENSORS_LIS3LV02D
-        tristate "STMicroeletronics LIS3LV02Dx three-axis digital accelerometer"
+        tristate "STMicroeletronics LIS3* three-axis digital accelerometer"
         depends on INPUT
         select INPUT_POLLDEV
         select NEW_LEDS
         select LEDS_CLASS
         default n
         help
-          This driver provides support for the LIS3LV02Dx accelerometer. In
-          particular, it can be found in a number of HP laptops, which have the
-          "Mobile Data Protection System 3D" or "3D DriveGuard" feature. On such
-          systems the driver should load automatically (via ACPI). The
-          accelerometer might also be found in other systems, connected via SPI
-          or I2C.  The accelerometer data is readable via
-          /sys/devices/platform/lis3lv02d.
+          This driver provides support for the LIS3* accelerometers, such as the
+          LIS3LV02DL or the LIS331DL. In particular, it can be found in a number
+          of HP laptops, which have the "Mobile Data Protection System 3D" or
+          "3D DriveGuard" feature. On such systems the driver should load
+          automatically (via ACPI alias). The accelerometer might also be found
+          in other systems, connected via SPI or I2C. The accelerometer data is
+          readable via /sys/devices/platform/lis3lv02d.
 
           This driver also provides an absolute input class device, allowing
-          the laptop to act as a pinball machine-esque joystick. On HP laptops,
+          a laptop to act as a pinball machine-esque joystick. It provides also
+          a misc device which can be used to detect free-fall. On HP laptops,
           if the led infrastructure is activated, support for a led indicating
-          disk protection will be provided as hp:red:hddprotection.
+          disk protection will be provided as hp::hddprotect. For more
+          information on the feature, refer to Documentation/hwmon/lis3lv02d.
 
           This driver can also be built as modules.  If so, the core module
           will be called lis3lv02d and a specific module for HP laptops will be
diff --git a/drivers/hwmon/lis3lv02d.c b/drivers/hwmon/lis3lv02d.c
index dbd0b055d4b9..1c8f10817e69 100644
--- a/drivers/hwmon/lis3lv02d.c
+++ b/drivers/hwmon/lis3lv02d.c
@@ -43,7 +43,7 @@
 #define MDPS_POLL_INTERVAL 50
 /*
  * The sensor can also generate interrupts (DRDY) but it's pretty pointless
- * because their are generated even if the data do not change. So it's better
+ * because they are generated even if the data do not change. So it's better
  * to keep the interrupt for the free-fall event. The values are updated at
  * 40Hz (at the lowest frequency), but as it can be pretty time consuming on
  * some low processor, we poll the sensor only at 20Hz... enough for the
@@ -65,7 +65,7 @@ static s16 lis3lv02d_read_8(struct lis3lv02d *lis3, int reg)
         return lo;
 }
 
-static s16 lis3lv02d_read_16(struct lis3lv02d *lis3, int reg)
+static s16 lis3lv02d_read_12(struct lis3lv02d *lis3, int reg)
 {
         u8 lo, hi;
 
@@ -411,20 +411,20 @@ EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
 
 /*
  * Initialise the accelerometer and the various subsystems.
- * Should be rather independant of the bus system.
+ * Should be rather independent of the bus system.
  */
 int lis3lv02d_init_device(struct lis3lv02d *dev)
 {
         dev->whoami = lis3lv02d_read_8(dev, WHO_AM_I);
 
         switch (dev->whoami) {
-        case LIS_DOUBLE_ID:
-                printk(KERN_INFO DRIVER_NAME ": 2-byte sensor found\n");
-                dev->read_data = lis3lv02d_read_16;
+        case WAI_12B:
+                printk(KERN_INFO DRIVER_NAME ": 12 bits sensor found\n");
+                dev->read_data = lis3lv02d_read_12;
                 dev->mdps_max_val = 2048;
                 break;
-        case LIS_SINGLE_ID:
-                printk(KERN_INFO DRIVER_NAME ": 1-byte sensor found\n");
+        case WAI_8B:
+                printk(KERN_INFO DRIVER_NAME ": 8 bits sensor found\n");
                 dev->read_data = lis3lv02d_read_8;
                 dev->mdps_max_val = 128;
                 break;
@@ -445,7 +445,7 @@ int lis3lv02d_init_device(struct lis3lv02d *dev)
         if (dev->pdata) {
                 struct lis3lv02d_platform_data *p = dev->pdata;
 
-                if (p->click_flags && (dev->whoami == LIS_SINGLE_ID)) {
+                if (p->click_flags && (dev->whoami == WAI_8B)) {
                         dev->write(dev, CLICK_CFG, p->click_flags);
                         dev->write(dev, CLICK_TIMELIMIT, p->click_time_limit);
                         dev->write(dev, CLICK_LATENCY, p->click_latency);
@@ -456,7 +456,7 @@ int lis3lv02d_init_device(struct lis3lv02d *dev)
                                         (p->click_thresh_y << 4));
                 }
 
-                if (p->wakeup_flags && (dev->whoami == LIS_SINGLE_ID)) {
+                if (p->wakeup_flags && (dev->whoami == WAI_8B)) {
                         dev->write(dev, FF_WU_CFG_1, p->wakeup_flags);
                         dev->write(dev, FF_WU_THS_1, p->wakeup_thresh & 0x7f);
                         /* default to 2.5ms for now */
diff --git a/drivers/hwmon/lis3lv02d.h b/drivers/hwmon/lis3lv02d.h
index 3e1ff46f72d3..2431c5199534 100644
--- a/drivers/hwmon/lis3lv02d.h
+++ b/drivers/hwmon/lis3lv02d.h
@@ -2,7 +2,7 @@
  *  lis3lv02d.h - ST LIS3LV02DL accelerometer driver
  *
  *  Copyright (C) 2007-2008 Yan Burman
- *  Copyright (C) 2008 Eric Piel
+ *  Copyright (C) 2008-2009 Eric Piel
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -22,20 +22,18 @@
 #include <linux/input-polldev.h>
 
 /*
- * The actual chip is STMicroelectronics LIS3LV02DL or LIS3LV02DQ that seems to
- * be connected via SPI. There exists also several similar chips (such as LIS302DL or
- * LIS3L02DQ) and they have slightly different registers, but we can provide a
- * common interface for all of them.
- * They can also be connected via I²C.
+ * This driver tries to support the "digital" accelerometer chips from
+ * STMicroelectronics such as LIS3LV02DL, LIS302DL, LIS3L02DQ, LIS331DL,
+ * LIS35DE, or LIS202DL. They are very similar in terms of programming, with
+ * almost the same registers. In addition to differing on physical properties,
+ * they differ on the number of axes (2/3), precision (8/12 bits), and special
+ * features (freefall detection, click...). Unfortunately, not all the
+ * differences can be probed via a register.
+ * They can be connected either via I²C or SPI.
  */
 
 #include <linux/lis3lv02d.h>
 
-/* 2-byte registers */
-#define LIS_DOUBLE_ID   0x3A /* LIS3LV02D[LQ] */
-/* 1-byte registers */
-#define LIS_SINGLE_ID   0x3B /* LIS[32]02DL and others */
-
 enum lis3_reg {
         WHO_AM_I        = 0x0F,
         OFFSET_X        = 0x16,
@@ -94,6 +92,12 @@ enum lis3lv02d_reg {
         DD_THSE_H       = 0x3F,
 };
 
+enum lis3_who_am_i {
+        WAI_12B         = 0x3A, /* 12 bits: LIS3LV02D[LQ]... */
+        WAI_8B          = 0x3B, /* 8 bits: LIS[23]02D[LQ]... */
+        WAI_6B          = 0x52, /* 6 bits: LIS331DLF - not supported */
+};
+
 enum lis3lv02d_ctrl1 {
         CTRL1_Xen       = 0x01,
         CTRL1_Yen       = 0x02,
@@ -194,7 +198,7 @@ struct lis3lv02d {
         int (*write) (struct lis3lv02d *lis3, int reg, u8 val);
         int (*read) (struct lis3lv02d *lis3, int reg, u8 *ret);
 
-        u8                      whoami;    /* 3Ah: 2-byte registries, 3Bh: 1-byte registries */
+        u8                      whoami;    /* indicates measurement precision */
         s16 (*read_data) (struct lis3lv02d *lis3, int reg);
         int                     mdps_max_val;