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authorÉric Piel <eric.piel@tremplin-utc.net>2009-12-14 18:01:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-15 08:53:36 -0800
commitbc62c1471773fc32adcfc05100abd16fa2b6e126 (patch)
tree34894261672d0c73c01b46ed92ebad7eb75ea8c4 /drivers
parent66c8569bf990064b3f11e0f211a81a46e0b627ff (diff)
downloadlwn-bc62c1471773fc32adcfc05100abd16fa2b6e126.tar.gz
lwn-bc62c1471773fc32adcfc05100abd16fa2b6e126.zip
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/hwmon/Kconfig22
-rw-r--r--drivers/hwmon/lis3lv02d.c20
-rw-r--r--drivers/hwmon/lis3lv02d.h28
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;