Kernel

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(add vibrator and backlight docs)
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root@fic-gta01:~$ cat /sys/bus/i2c/devices/0-0008/battemp
 
root@fic-gta01:~$ cat /sys/bus/i2c/devices/0-0008/battemp
 
25
 
25
 +
</pre>
 +
 +
=== Backlight ===
 +
 +
We provide a driver that supports the linux kernel standard backlight API. You can find the respective sysfs files in /sys/class/backlight/
 +
 +
=== Vibrator ===
 +
 +
The vibrator driver is implemented as a LED driver.  You can find the respective sysfs files in /sys/class/led/.
 +
The vibrator classdev name is '''gta01:vibrator'''.
 +
 +
Please note, depending on the kernel version, the driver only supports on/off or PWM of the vibrator device.  If you want to run the vibrator at full power, use
 +
<pre>
 +
root@fic-gta01:~$ echo "255" > /sys/class/leds/gta01\:vibrator/brightness
 
</pre>
 
</pre>
  

Revision as of 06:17, 18 October 2007

Contents

General

The Kernel on the GTA01 is based on a vanilla 2.6.21.3 Linux kernel from kernel.org.

Some additional patches are required for

  • S3C2410 Usb Device Controller
    • We use the driver from iPaq H1940 linux project
  • S3C2410 SD Card Controller
  • QT2410 machine support
    • This is just some glue that puts all pieces together
  • S3C2410 touch screen driver
    • Again from iPaq H1940 linux project
  • GTA01 machine support
    • Some glue/configuration to pull all pieces together
  • GSM Communication Infrastructure
    • The kernel-level part (TS07.10 line discipline, GPRS line discipline)

Kernel Patchset

The latest patchset against the abovementioned vanilla kernel can be found at https://svn.openmoko.org/trunk/src/target/kernel/patches/. This is a so-called "quilt patchset". In order to apply it, you have to download it into a "patches" directory below the "linux-2.6.x" directory, and then call "quilt push -a", which pushes all patches onto the kernel.

For example, after unpacking the 2.6.21.1 kernel tarball, you might type the following commands:

   cd linux-2.6.21.1
   svn co https://svn.openmoko.org/trunk/src/target/kernel/patches
   quilt push -a

to apply the latest patchset to that kernel. Note that 2.6.21.1 may not be the correct kernel to build against - see previous section to determine just which kernel version to download and patch.

Kernel Configuration

The latest kernel configuration file can be found at https://svn.openmoko.org/trunk/oe/packages/linux/linux-gta01/. Just copy the config file corresponding to the correct kernel version to the linux-2.6.x/.config file.

Kernel building

The kernel build is executed as normal. We actually only need the "vmlinux" target, not the "zImage".

Prebuilt kernel images

Prebuilt bootable kernel images called uImage* are available from:

For full operation on the currently supported platforms you need some modules inside the rootfs. You can either get a modules* archive from the above mentioned location (with the same version number) which contains many more modules then you might need.

Alternatively you can check the following location for prepackaged modules for the kernel version and install them using ipkg:

Modules for the Neo1973 GTA01

On the Neo1973 the following modules should be added to support most of the hardware:

  • snd-soc-neo1973-wm8753 snd-soc-s3c24xx-i2s snd-soc-s3c24xx snd-soc-wm8753
  • ohci-hcd
  • bluetooth hci-usb
  • fat vfat msdos nsl-base nls_iso8859_1 nls_cp437

These really should be in the unmodified root image to start with. See bug 580.

You'll probably have to put these in a file in /etc/modutils/ and run update-modules to get them to work automatically.

  • hci_usb
  • s3cmci
  • snd-soc-neo1973-wm8753

Creating a bootable kernel image

u-boot needs all images (such as kernel, initrd, ...) in the form of an uImage. This is basically just a special header adding CRC protection, version information, etc. Please see u-boot for details.

Kernel Boot Parameters

Since the QT2410 can be used with different liquid crystal modules (LCMs), the kernel images for the QT2410 have a boot parameter "tft":

  • If you boot without any tft= parameter, the 'stock' qt2410 240x320 TFT panel is assumed.
  • If you boot with "tft=b" ('b' for big), the timings for the SHARP 8" 640x480 TFT panel are used.
  • If you boot with "tft=p" ('p' for production), the timings for the 2.8" 480x640 TFT panel are used.

Kernel Subsystems

In this section we will outline a couple of the GTA01 specific kernel drivers / features / subsystems

GSM

Power Management

The gta01_pm_gsm driver implements GSM power management (this means, if this is compiled as a module, you have to load the gta01_pm_gsm.ko module first)

It exports the following sysfs based interface

root@fic-gta01:/$ ls -l /sys/bus/platform/devices/gta01-pm-gsm.0/
-rw-r--r--    1 root     root         4096 Feb  1 09:58 download
-rw-r--r--    1 root     root         4096 Feb  1 09:58 power_on
-rw-r--r--    1 root     root         4096 Feb  1 09:58 reset
Powering up/down
root@fic-gta01:~$ echo "1" > /sys/bus/platform/devices/gta01-pm-gsm.0/power_on 
gta01-pm-gsm gta01-pm-gsm.0: powering up GSM, thus disconnecting serial console

root@fic-gta01:~$ echo "0" > /sys/bus/platform/devices/gta01-pm-gsm.0/power_on 
gta01-pm-gsm gta01-pm-gsm.0: powered down GSM, thus enabling serial console

Note that powering up GSM disables the console.

Resetting
root@fic-gta01:~$ echo "1" > /sys/bus/platform/devices/gta01-pm-gsm.0/reset 
root@fic-gta01:~$ echo "0" > /sys/bus/platform/devices/gta01-pm-gsm.0/reset 
Activating GSM baseband download mode
root@fic-gta01:~$ echo "1" > /sys/bus/platform/devices/gta01-pm-gsm.0/download
De-activating GSM baseband download mode
root@fic-gta01:~$ echo "0" > /sys/bus/platform/devices/gta01-pm-gsm.0/download

GPS

Power Management

The gta01_pm_gps kernel driver offers a sysfs based interface:

root@fic-gta01:~$ ls -l /sys/bus/platform/devices/gta01-pm-gps.0/     
-rw-r--r--    1 root     root         4096 Feb  1 09:14 power_avdd_3v
-rw-r--r--    1 root     root         4096 Feb  1 09:14 power_lp_io_3v3
-rw-r--r--    1 root     root         4096 Feb  1 09:14 power_pll_core_2v5
-rw-r--r--    1 root     root            0 Feb  1 09:14 power_sequence
-rw-r--r--    1 root     root         4096 Feb  1 09:14 power_vtxco_2v8
-rw-r--r--    1 root     root         4096 Feb  1 09:14 pwron
-rw-r--r--    1 root     root         4096 Feb  1 09:14 reset

The power_avdd_3v, power_lp_io_3v3, power_pll_core_2v5, power_vtxco_2v8, pwron and reset files represent the state of the respective signal.

The power_sequence file implements power-up/power-down sequence in accordance with the GlobalLocate data sheet.

Powering up
root@fic-gta01:~$ echo "power_up" > /sys/bus/platform/devices/gta01-pm-gps.0/power_sequence 
Powering down
root@fic-gta01:~$ echo "power_down" > /sys/bus/platform/devices/gta01-pm-gps.0/power_sequence

Asound driver

High-level requirements

The GTA01 audio subsystem is fairly complex, even though the high-level requirements for the sound driver are simple. The features we need to support

  • voice call support
    • passing through the microphone signal to the GSM Modem
    • passing through the GSM Modem audio output to the integrated speaker(s)
    • the microphone input mixer gain will be statically configured according to the dynamic requirements
    • the audio volume that is sent to the GSM modem can be adjusted via line out level
    • the audio volume incoming (from GSM modem -> codec) can be adjusted via speaker out level
  • voice call recording support
    • the user is able to record phone conversations on digital storage inside the phone. Format will be ogg (not important to driver)
    • ideally, the user can choose between recording only incoming or outgoing signal, or both.
    • for both, we'd need to mix both microphone and line-in signals before recording. is this possible?
  • voice call playback support
    • the user is able to playback recorded files during a conversation. this means that PCM playback needs to be mixed with mic input before being passed to line-out (and to the GSM modem)
  • media playback support
    • an audio player can play back mp3/ogg/flac/... files and output sound via integrated speakers or headphone
  • headphone jack switch
    • this is connected to a GPIO of the S3C2410. How to best integrate this with the sound driver? It should just be handled like any other headphone jack reporting of e.g. laptop computers.

For more details see Neo1973 Audio Subsystem

Bluetooth

We're using the stock bluez implementation of the linux kernel.

Power Management

The bluetooth basically has the following preconditions

  • BT_EN being set
  • The Voltage regulator set up properly
  • The ohci-hcd driver being loaded

The gta01_pm_bt driver implements the following files:

root@fic-gta01:/$ ls -l /sys/bus/platform/devices/gta01-pm-bt.0
-rw-r--r--    1 root     root         4096 Feb  1 09:52 power_on
-rw-r--r--    1 root     root         4096 Feb  1 09:52 reset
Powering up the device
root@fic-gta01:/$ echo "1" > /sys/bus/platform/devices/gta01-pm-bt.0/power_on
usb 1-1: new full speed USB device using s3c2410-ohci and address 4
usb 1-1: configuration #1 chosen from 1 choice
Powering down the device
root@fic-gta01:/$ echo "0" > /sys/bus/platform/devices/gta01-pm-bt.0/power_on 
usb 1-1: USB disconnect, address 3
Asserting reset (low-active)
root@fic-gta01:/$ echo "0" >  /sys/bus/platform/devices/gta01-pm-bt.0/reset 
root@fic-gta01:/$ usb 1-1: USB disconnect, address 2
De-asserting reset (low-active)
root@fic-gta01:/$ echo "1" >  /sys/bus/platform/devices/gta01-pm-bt.0/reset 
s3c2410-ohci s3c2410-ohci: wakeup
usb 1-1: new full speed USB device using s3c2410-ohci and address 3
usb 1-1: configuration #1 chosen from 1 choice

Getting started

root@fic-gta01:~$ hciconfig hci0 up
root@fic-gta01:~$ hcitool  scan
Scanning ...
        00:14:9A:77:A2:02       A780
root@fic-gta01:~$ hcitool inq 00:14:9A:77:A2:02 
Inquiring ...
        00:14:9A:77:A2:02       clock offset: 0x55df    class: 0x502204
root@fic-gta01:~$ hcitool cc 00:14:9A:77:A2:02 
root@fic-gta01:~$ hcitool con                 
Connections:
        < ACL 00:14:9A:77:A2:02 handle 42 state 1 lm MASTER 
root@fic-gta01:~$ hcitool info 00:14:9A:77:A2:02
Requesting information ...
        BD Address:  00:14:9A:77:A2:02
        Device Name: A780
        LMP Version: 1.1 (0x1) LMP Subversion: 0x700
        Manufacturer: Broadcom Corporation (15)
        Features: 0xff 0xff 0x0d 0x00 0x00 0x00 0x00 0x00
                <3-slot packets> <5-slot packets> <encryption> <slot offset> 
                <timing accuracy> <role switch> <hold mode> <sniff mode> 
                <park state> <RSSI> <channel quality> <SCO link> <HV2 packets> 
                <HV3 packets> <u-law log> <A-law log> <CVSD> <power control> 
                <transparent SCO> 

AUX Button

The AUX button (formerly 911 button) is supported via the "gta01kbd" driver in the kernel (drivers/input/keyboard/gta01kbd.c).

It creates an input event device that only issues "KEY_PHONE" press/unpress events.

Power Management Unit (PMU)

The PMU is supported via the "pcf50606" driver in the kernel (drivers/i2c/chips/pcf50606.c).

This driver provides a number of userspace interfaces for the various bits and pieces of the PMU

Power Button, Charger insertion

The PMU creates an input device that supports the following keys:

  • KEY_POWER: power button of GTA01
  • KEY_POWER2: USB power supply insert/remove
  • KEY_BATTERY: Charger insert/remove

RTC

The real-time clock, including the alarm feature, is implemented as standard RTC (/dev/rtc).

Watchdog

The PMU-integrated watchdog is implemented using the standard watchdog character device.

Voltage Regulators

The voltage regulators are exported to userspace using sysfs, much like lm_sensors.

Every regulator can be read (and written!). The format is ASCII in millivolts.

root@fic-gta01:/sys/devices/platform/s3c2410-i2c/i2c-0/0-0008$ ls -l /sys/bus/i2c/devices/0-0008/voltage_*
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_d1reg
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_d2reg
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_d3reg
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_dcd
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_dcde
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_dcud
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_lpreg
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_ioreg
root@fic-gta01:/sys/devices/platform/s3c2410-i2c/i2c-0/0-0008$ cat voltage_dcd
1300

Battery Voltage

The battery voltage (in millivolts) can be read via sysfs

root@fic-gta01:~$ cat /sys/bus/i2c/devices/0-0008/battvolt 
3767

Battery charging current

The battery charging current (in milliamperes) can be read via sysfs

root@fic-gta01:~$ cat /sys/bus/i2c/devices/0-0008/chgcur 
0

Battery temperature

The battery temperature (in centigrades) can be read via sysfs

root@fic-gta01:~$ cat /sys/bus/i2c/devices/0-0008/battemp
25

Backlight

We provide a driver that supports the linux kernel standard backlight API. You can find the respective sysfs files in /sys/class/backlight/

Vibrator

The vibrator driver is implemented as a LED driver. You can find the respective sysfs files in /sys/class/led/. The vibrator classdev name is gta01:vibrator.

Please note, depending on the kernel version, the driver only supports on/off or PWM of the vibrator device. If you want to run the vibrator at full power, use

root@fic-gta01:~$ echo "255" > /sys/class/leds/gta01\:vibrator/brightness

Kernel TODO

Various

  • speed up in-kernel boot process
    • delay calibration
    • framebuffer takes ages

TS07.10 multiplex

PCF50606

  • check conversion table for temperature
  • implement 'persistent alarm setting' (see mail from mickey)

USB device driver

  • test switching between usb host and usb device

Mailing list

OpenMoko related kernel development discussions happen on the openmoko-kernel@lists.openmoko.org mailing list.

Personal tools

General

The Kernel on the GTA01 is based on a vanilla 2.6.21.3 Linux kernel from kernel.org.

Some additional patches are required for

  • S3C2410 Usb Device Controller
    • We use the driver from iPaq H1940 linux project
  • S3C2410 SD Card Controller
  • QT2410 machine support
    • This is just some glue that puts all pieces together
  • S3C2410 touch screen driver
    • Again from iPaq H1940 linux project
  • GTA01 machine support
    • Some glue/configuration to pull all pieces together
  • GSM Communication Infrastructure
    • The kernel-level part (TS07.10 line discipline, GPRS line discipline)

Kernel Patchset

The latest patchset against the abovementioned vanilla kernel can be found at https://svn.openmoko.org/trunk/src/target/kernel/patches/. This is a so-called "quilt patchset". In order to apply it, you have to download it into a "patches" directory below the "linux-2.6.x" directory, and then call "quilt push -a", which pushes all patches onto the kernel.

For example, after unpacking the 2.6.21.1 kernel tarball, you might type the following commands:

   cd linux-2.6.21.1
   svn co https://svn.openmoko.org/trunk/src/target/kernel/patches
   quilt push -a

to apply the latest patchset to that kernel. Note that 2.6.21.1 may not be the correct kernel to build against - see previous section to determine just which kernel version to download and patch.

Kernel Configuration

The latest kernel configuration file can be found at https://svn.openmoko.org/trunk/oe/packages/linux/linux-gta01/. Just copy the config file corresponding to the correct kernel version to the linux-2.6.x/.config file.

Kernel building

The kernel build is executed as normal. We actually only need the "vmlinux" target, not the "zImage".

Prebuilt kernel images

Prebuilt bootable kernel images called uImage* are available from:

For full operation on the currently supported platforms you need some modules inside the rootfs. You can either get a modules* archive from the above mentioned location (with the same version number) which contains many more modules then you might need.

Alternatively you can check the following location for prepackaged modules for the kernel version and install them using ipkg:

Modules for the Neo1973 GTA01

On the Neo1973 the following modules should be added to support most of the hardware:

  • snd-soc-neo1973-wm8753 snd-soc-s3c24xx-i2s snd-soc-s3c24xx snd-soc-wm8753
  • ohci-hcd
  • bluetooth hci-usb
  • fat vfat msdos nsl-base nls_iso8859_1 nls_cp437

These really should be in the unmodified root image to start with. See bug 580.

You'll probably have to put these in a file in /etc/modutils/ and run update-modules to get them to work automatically.

  • hci_usb
  • s3cmci
  • snd-soc-neo1973-wm8753

Creating a bootable kernel image

u-boot needs all images (such as kernel, initrd, ...) in the form of an uImage. This is basically just a special header adding CRC protection, version information, etc. Please see u-boot for details.

Kernel Boot Parameters

Since the QT2410 can be used with different liquid crystal modules (LCMs), the kernel images for the QT2410 have a boot parameter "tft":

  • If you boot without any tft= parameter, the 'stock' qt2410 240x320 TFT panel is assumed.
  • If you boot with "tft=b" ('b' for big), the timings for the SHARP 8" 640x480 TFT panel are used.
  • If you boot with "tft=p" ('p' for production), the timings for the 2.8" 480x640 TFT panel are used.

Kernel Subsystems

In this section we will outline a couple of the GTA01 specific kernel drivers / features / subsystems

GSM

Power Management

The gta01_pm_gsm driver implements GSM power management (this means, if this is compiled as a module, you have to load the gta01_pm_gsm.ko module first)

It exports the following sysfs based interface

root@fic-gta01:/$ ls -l /sys/bus/platform/devices/gta01-pm-gsm.0/
-rw-r--r--    1 root     root         4096 Feb  1 09:58 download
-rw-r--r--    1 root     root         4096 Feb  1 09:58 power_on
-rw-r--r--    1 root     root         4096 Feb  1 09:58 reset
Powering up/down
root@fic-gta01:~$ echo "1" > /sys/bus/platform/devices/gta01-pm-gsm.0/power_on 
gta01-pm-gsm gta01-pm-gsm.0: powering up GSM, thus disconnecting serial console

root@fic-gta01:~$ echo "0" > /sys/bus/platform/devices/gta01-pm-gsm.0/power_on 
gta01-pm-gsm gta01-pm-gsm.0: powered down GSM, thus enabling serial console

Note that powering up GSM disables the console.

Resetting
root@fic-gta01:~$ echo "1" > /sys/bus/platform/devices/gta01-pm-gsm.0/reset 
root@fic-gta01:~$ echo "0" > /sys/bus/platform/devices/gta01-pm-gsm.0/reset 
Activating GSM baseband download mode
root@fic-gta01:~$ echo "1" > /sys/bus/platform/devices/gta01-pm-gsm.0/download
De-activating GSM baseband download mode
root@fic-gta01:~$ echo "0" > /sys/bus/platform/devices/gta01-pm-gsm.0/download

GPS

Power Management

The gta01_pm_gps kernel driver offers a sysfs based interface:

root@fic-gta01:~$ ls -l /sys/bus/platform/devices/gta01-pm-gps.0/     
-rw-r--r--    1 root     root         4096 Feb  1 09:14 power_avdd_3v
-rw-r--r--    1 root     root         4096 Feb  1 09:14 power_lp_io_3v3
-rw-r--r--    1 root     root         4096 Feb  1 09:14 power_pll_core_2v5
-rw-r--r--    1 root     root            0 Feb  1 09:14 power_sequence
-rw-r--r--    1 root     root         4096 Feb  1 09:14 power_vtxco_2v8
-rw-r--r--    1 root     root         4096 Feb  1 09:14 pwron
-rw-r--r--    1 root     root         4096 Feb  1 09:14 reset

The power_avdd_3v, power_lp_io_3v3, power_pll_core_2v5, power_vtxco_2v8, pwron and reset files represent the state of the respective signal.

The power_sequence file implements power-up/power-down sequence in accordance with the GlobalLocate data sheet.

Powering up
root@fic-gta01:~$ echo "power_up" > /sys/bus/platform/devices/gta01-pm-gps.0/power_sequence 
Powering down
root@fic-gta01:~$ echo "power_down" > /sys/bus/platform/devices/gta01-pm-gps.0/power_sequence

Asound driver

High-level requirements

The GTA01 audio subsystem is fairly complex, even though the high-level requirements for the sound driver are simple. The features we need to support

  • voice call support
    • passing through the microphone signal to the GSM Modem
    • passing through the GSM Modem audio output to the integrated speaker(s)
    • the microphone input mixer gain will be statically configured according to the dynamic requirements
    • the audio volume that is sent to the GSM modem can be adjusted via line out level
    • the audio volume incoming (from GSM modem -> codec) can be adjusted via speaker out level
  • voice call recording support
    • the user is able to record phone conversations on digital storage inside the phone. Format will be ogg (not important to driver)
    • ideally, the user can choose between recording only incoming or outgoing signal, or both.
    • for both, we'd need to mix both microphone and line-in signals before recording. is this possible?
  • voice call playback support
    • the user is able to playback recorded files during a conversation. this means that PCM playback needs to be mixed with mic input before being passed to line-out (and to the GSM modem)
  • media playback support
    • an audio player can play back mp3/ogg/flac/... files and output sound via integrated speakers or headphone
  • headphone jack switch
    • this is connected to a GPIO of the S3C2410. How to best integrate this with the sound driver? It should just be handled like any other headphone jack reporting of e.g. laptop computers.

For more details see Neo1973 Audio Subsystem

Bluetooth

We're using the stock bluez implementation of the linux kernel.

Power Management

The bluetooth basically has the following preconditions

  • BT_EN being set
  • The Voltage regulator set up properly
  • The ohci-hcd driver being loaded

The gta01_pm_bt driver implements the following files:

root@fic-gta01:/$ ls -l /sys/bus/platform/devices/gta01-pm-bt.0
-rw-r--r--    1 root     root         4096 Feb  1 09:52 power_on
-rw-r--r--    1 root     root         4096 Feb  1 09:52 reset
Powering up the device
root@fic-gta01:/$ echo "1" > /sys/bus/platform/devices/gta01-pm-bt.0/power_on
usb 1-1: new full speed USB device using s3c2410-ohci and address 4
usb 1-1: configuration #1 chosen from 1 choice
Powering down the device
root@fic-gta01:/$ echo "0" > /sys/bus/platform/devices/gta01-pm-bt.0/power_on 
usb 1-1: USB disconnect, address 3
Asserting reset (low-active)
root@fic-gta01:/$ echo "0" >  /sys/bus/platform/devices/gta01-pm-bt.0/reset 
root@fic-gta01:/$ usb 1-1: USB disconnect, address 2
De-asserting reset (low-active)
root@fic-gta01:/$ echo "1" >  /sys/bus/platform/devices/gta01-pm-bt.0/reset 
s3c2410-ohci s3c2410-ohci: wakeup
usb 1-1: new full speed USB device using s3c2410-ohci and address 3
usb 1-1: configuration #1 chosen from 1 choice

Getting started

root@fic-gta01:~$ hciconfig hci0 up
root@fic-gta01:~$ hcitool  scan
Scanning ...
        00:14:9A:77:A2:02       A780
root@fic-gta01:~$ hcitool inq 00:14:9A:77:A2:02 
Inquiring ...
        00:14:9A:77:A2:02       clock offset: 0x55df    class: 0x502204
root@fic-gta01:~$ hcitool cc 00:14:9A:77:A2:02 
root@fic-gta01:~$ hcitool con                 
Connections:
        < ACL 00:14:9A:77:A2:02 handle 42 state 1 lm MASTER 
root@fic-gta01:~$ hcitool info 00:14:9A:77:A2:02
Requesting information ...
        BD Address:  00:14:9A:77:A2:02
        Device Name: A780
        LMP Version: 1.1 (0x1) LMP Subversion: 0x700
        Manufacturer: Broadcom Corporation (15)
        Features: 0xff 0xff 0x0d 0x00 0x00 0x00 0x00 0x00
                <3-slot packets> <5-slot packets> <encryption> <slot offset> 
                <timing accuracy> <role switch> <hold mode> <sniff mode> 
                <park state> <RSSI> <channel quality> <SCO link> <HV2 packets> 
                <HV3 packets> <u-law log> <A-law log> <CVSD> <power control> 
                <transparent SCO> 

AUX Button

The AUX button (formerly 911 button) is supported via the "gta01kbd" driver in the kernel (drivers/input/keyboard/gta01kbd.c).

It creates an input event device that only issues "KEY_PHONE" press/unpress events.

Power Management Unit (PMU)

The PMU is supported via the "pcf50606" driver in the kernel (drivers/i2c/chips/pcf50606.c).

This driver provides a number of userspace interfaces for the various bits and pieces of the PMU

Power Button, Charger insertion

The PMU creates an input device that supports the following keys:

  • KEY_POWER: power button of GTA01
  • KEY_POWER2: USB power supply insert/remove
  • KEY_BATTERY: Charger insert/remove

RTC

The real-time clock, including the alarm feature, is implemented as standard RTC (/dev/rtc).

Watchdog

The PMU-integrated watchdog is implemented using the standard watchdog character device.

Voltage Regulators

The voltage regulators are exported to userspace using sysfs, much like lm_sensors.

Every regulator can be read (and written!). The format is ASCII in millivolts.

root@fic-gta01:/sys/devices/platform/s3c2410-i2c/i2c-0/0-0008$ ls -l /sys/bus/i2c/devices/0-0008/voltage_*
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_d1reg
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_d2reg
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_d3reg
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_dcd
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_dcde
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_dcud
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_lpreg
-rw-r--r--    1 root     root         4096 Sep  3 11:55 /sys/bus/i2c/devices/0-0008/voltage_ioreg
root@fic-gta01:/sys/devices/platform/s3c2410-i2c/i2c-0/0-0008$ cat voltage_dcd
1300

Battery Voltage

The battery voltage (in millivolts) can be read via sysfs

root@fic-gta01:~$ cat /sys/bus/i2c/devices/0-0008/battvolt 
3767

Battery charging current

The battery charging current (in milliamperes) can be read via sysfs

root@fic-gta01:~$ cat /sys/bus/i2c/devices/0-0008/chgcur 
0

Battery temperature

The battery temperature (in centigrades) can be read via sysfs

root@fic-gta01:~$ cat /sys/bus/i2c/devices/0-0008/battemp
25

Backlight

We provide a driver that supports the linux kernel standard backlight API. You can find the respective sysfs files in /sys/class/backlight/

Vibrator

The vibrator driver is implemented as a LED driver. You can find the respective sysfs files in /sys/class/led/. The vibrator classdev name is gta01:vibrator.

Please note, depending on the kernel version, the driver only supports on/off or PWM of the vibrator device. If you want to run the vibrator at full power, use

root@fic-gta01:~$ echo "255" > /sys/class/leds/gta01\:vibrator/brightness

Kernel TODO

Various

  • speed up in-kernel boot process
    • delay calibration
    • framebuffer takes ages

TS07.10 multiplex

PCF50606

  • check conversion table for temperature
  • implement 'persistent alarm setting' (see mail from mickey)

USB device driver

  • test switching between usb host and usb device

Mailing list

OpenMoko related kernel development discussions happen on the openmoko-kernel@lists.openmoko.org mailing list.