The Kernel on the GTA01 is based on a vanilla 22.214.171.124 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
- We use the driver from the TomTom GO kernel
- 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)
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 untar 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.
The latest kernel configuration can be found at https://svn.openmoko.org/trunk/oe/packages/linux/linux-gta01/defconfig-fic-gta01. Just copy it to the linux-2.6.x/.config file.
The kernel build is executed as normal. We actually only need the "vmlinux" target, not the "zImage".
Bootable kernel image
A bootable kernel image called uImage is available from )
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. Pleaes 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.
In this section we will outline a couple of the GTA01 specific kernel drivers / features / subsystems
The gta01_pm_gsm driver implements GSM power management.
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
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
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
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.
root@fic-gta01:~$ echo "power_up" > /sys/bus/platform/devices/gta01-pm-gps.0/power_sequence
root@fic-gta01:~$ echo "power_down" > /sys/bus/platform/devices/gta01-pm-gps.0/power_sequence
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
We're using the stock bluez implementation of the linux kernel.
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/devices/platform/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/devices/platform/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/devices/platform/gta01-pm-bt.0/power_on usb 1-1: USB disconnect, address 3
Asserting reset (low-active)
root@fic-gta01:/$ echo "0" > /sys/devices/platform/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/devices/platform/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
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>
The 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
The real-time clock, including the alarm feature, is implemented as standard RTC (/dev/rtc).
The PMU-integrated watchdog is implemented using the standard watchdog character device.
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
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
The battery temperature (in centigrades) can be read via sysfs
root@fic-gta01:~$ cat /sys/bus/i2c/devices/0-0008/battemp 25
- speed up in-kernel boot process
- delay calibration
- framebuffer takes ages
- fix conversion problems when setting alarm time/date
- check conversion table for temperature
- implement 'persistent alarm setting' (see mail from mickey)
- later: implement smooth fade-in, fade-out
- implement it as LED driver
- test it
- later: implement PWM
USB device driver
- test switching between usb host and usb device
- test, debug and fix suspend on user request
- test, debug and fix wakeup on
- IRQ on serial UART (GSM)
- IRQ on serial UART (GPS)
- IRQ from PMU (charger insert/remove or the like)
- IRQ from ADC/touchscreen
- 911 button press (GPIO IRQ)
- headphone jack insert/remove