[PATCH v2 03/10] lis3: Update documentation and comments

From: Samu Onkalo
Date: Tue Nov 10 2009 - 07:42:39 EST

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From: Ãric Piel <eric.piel@xxxxxxxxxxxxxxxx>

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: Ãric Piel <eric.piel@xxxxxxxxxxxxxxxx>
---
Documentation/hwmon/lis3lv02d | 24 ++++++++++++++----------
drivers/hwmon/Kconfig | 22 ++++++++++++----------
drivers/hwmon/lis3lv02d.c | 20 ++++++++++----------
drivers/hwmon/lis3lv02d.h | 28 ++++++++++++++++------------
4 files changed, 52 insertions(+), 42 deletions(-)

diff --git a/Documentation/hwmon/lis3lv02d b/Documentation/hwmon/lis3lv02d
index effe949..21f0902 100644
--- a/Documentation/hwmon/lis3lv02d
+++ b/Documentation/hwmon/lis3lv02d
@@ -3,7 +3,8 @@ Kernel driver lis3lv02d

Supported chips:

- * STMicroelectronics LIS3LV02DL and LIS3LV02DQ
+ * STMicroelectronics LIS3LV02DL, LIS3LV02DQ (12 bits precision)
+ * STMicroelectronics LIS302DL, LIS3L02DQ, LIS331DL (8 bits)

Authors:
Yan Burman <burman.yan@xxxxxxxxx>
@@ -13,13 +14,12 @@ Authors:
Description
-----------

-This driver provides support for the accelerometer found in various HP
-laptops sporting the feature officially called "HP Mobile Data
-Protection System 3D" or "HP 3D DriveGuard". It detects automatically
-laptops with this sensor. Known models (for now the HP 2133, nc6420,
-nc2510, nc8510, nc84x0, nw9440 and nx9420) will have their axis
-automatically oriented on standard way (eg: you can directly play
-neverball). The accelerometer data is readable via
+This driver provides support for the accelerometer found in various HP laptops
+sporting the feature officially called "HP Mobile Data Protection System 3D" or
+"HP 3D DriveGuard". It detects automatically laptops with this sensor. Known
+models (full list can be found in drivers/hwmon/hp_accel.c) will have their
+axis automatically oriented on standard way (eg: you can directly play
+neverball). The accelerometer data is readable via
/sys/devices/platform/lis3lv02d.

Sysfs attributes under /sys/devices/platform/lis3lv02d/:
@@ -33,12 +33,16 @@ rate - reports the sampling rate of the accelerometer device in HZ
This driver also provides an absolute input class device, allowing
the laptop to act as a pinball machine-esque joystick.

+On HP laptops, if the led infrastructure is activated, support for a led
+indicating disk protection will be provided as /sys/class/leds/hp::hddprotect.
+
Another feature of the driver is misc device called "freefall" that
acts similar to /dev/rtc and reacts on free-fall interrupts received
from the device. It supports blocking operations, poll/select and
fasync operation modes. You must read 1 bytes from the device. The
result is number of free-fall interrupts since the last successful
-read (or 255 if number of interrupts would not fit).
+read (or 255 if number of interrupts would not fit). See the hpfall.c
+file for an example on using the device.

Axes orientation
@@ -55,7 +59,7 @@ the accelerometer are converted into a "standard" organisation of the axes
* If the laptop is put upside-down, Z becomes negative

If your laptop model is not recognized (cf "dmesg"), you can send an
-email to the authors to add it to the database. When reporting a new
+email to the maintainer to add it to the database. When reporting a new
laptop, please include the output of "dmidecode" plus the value of
/sys/devices/platform/lis3lv02d/position in these four cases.

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 700e93a..a9afb1b 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1025,25 +1025,27 @@ 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 dbd0b05..1c8f108 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 3e1ff46..2431c51 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 IÂC.
+ * 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 IÂC 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;

--
1.5.6.3

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Next message: Samu Onkalo: "[PATCH v2 10/10] LIS3: Update documentation to match latest changes"
Previous message: Samu Onkalo: "[PATCH v2 02/10] LIS3LV02D: Correct memory leak in module unload"
In reply to: Samu Onkalo: "[PATCH v2 02/10] LIS3LV02D: Correct memory leak in module unload"
Next in thread: Samu Onkalo: "[PATCH v2 04/10] lis3: fix show rate for 8 bits chips"
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