Commit 82e6923e authored by Russell King's avatar Russell King
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ARM: lh7a40x: remove unmaintained platform support



lh7a40x has only been receiving updates for updates to generic code.
The last involvement from the maintainer according to the git logs was
in 2006.  As such, it is a maintainence burden with no benefit.

This gets rid of two defconfigs.
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 1bae4ce2
README on the ADC/Touchscreen Controller
========================================
The LH79524 and LH7A404 include a built-in Analog to Digital
controller (ADC) that is used to process input from a touchscreen.
The driver only implements a four-wire touch panel protocol.
The touchscreen driver is maintenance free except for the pen-down or
touch threshold. Some resistive displays and board combinations may
require tuning of this threshold. The driver exposes some of its
internal state in the sys filesystem. If the kernel is configured
with it, CONFIG_SYSFS, and sysfs is mounted at /sys, there will be a
directory
/sys/devices/platform/adc-lh7.0
containing these files.
-r--r--r-- 1 root root 4096 Jan 1 00:00 samples
-rw-r--r-- 1 root root 4096 Jan 1 00:00 threshold
-r--r--r-- 1 root root 4096 Jan 1 00:00 threshold_range
The threshold is the current touch threshold. It defaults to 750 on
most targets.
# cat threshold
750
The threshold_range contains the range of valid values for the
threshold. Values outside of this range will be silently ignored.
# cat threshold_range
0 1023
To change the threshold, write a value to the threshold file.
# echo 500 > threshold
# cat threshold
500
The samples file contains the most recently sampled values from the
ADC. There are 12. Below are typical of the last sampled values when
the pen has been released. The first two and last two samples are for
detecting whether or not the pen is down. The third through sixth are
X coordinate samples. The seventh through tenth are Y coordinate
samples.
# cat samples
1023 1023 0 0 0 0 530 529 530 529 1023 1023
To determine a reasonable threshold, press on the touch panel with an
appropriate stylus and read the values from samples.
# cat samples
1023 676 92 103 101 102 855 919 922 922 1023 679
The first and eleventh samples are discarded. Thus, the important
values are the second and twelfth which are used to determine if the
pen is down. When both are below the threshold, the driver registers
that the pen is down. When either is above the threshold, it
registers then pen is up.
README on the Compact Flash for Card Engines
============================================
There are three challenges in supporting the CF interface of the Card
Engines. First, every IO operation must be followed with IO to
another memory region. Second, the slot is wired for one-to-one
address mapping *and* it is wired for 16 bit access only. Second, the
interrupt request line from the CF device isn't wired.
The IOBARRIER issue is covered in README.IOBARRIER. This isn't an
onerous problem. Enough said here.
The addressing issue is solved in the
arch/arm/mach-lh7a40x/ide-lpd7a40x.c file with some awkward
work-arounds. We implement a special SELECT_DRIVE routine that is
called before the IDE driver performs its own SELECT_DRIVE. Our code
recognizes that the SELECT register cannot be modified without also
writing a command. It send an IDLE_IMMEDIATE command on selecting a
drive. The function also prevents drive select to the slave drive
since there can be only one. The awkward part is that the IDE driver,
even though we have a select procedure, also attempts to change the
drive by writing directly the SELECT register. This attempt is
explicitly blocked by the OUTB function--not pretty, but effective.
The lack of interrupts is a more serious problem. Even though the CF
card is fast when compared to a normal IDE device, we don't know that
the CF is really flash. A user could use one of the very small hard
drives being shipped with a CF interface. The IDE code includes a
check for interfaces that lack an IRQ. In these cases, submitting a
command to the IDE controller is followed by a call to poll for
completion. If the device isn't immediately ready, it schedules a
timer to poll again later.
README on the IOBARRIER for CardEngine IO
=========================================
Due to an unfortunate oversight when the Card Engines were designed,
the signals that control access to some peripherals, most notably the
SMC91C9111 ethernet controller, are not properly handled.
The symptom is that some back to back IO with the peripheral returns
unreliable data. With the SMC chip, you'll see errors about the bank
register being 'screwed'.
The cause is that the AEN signal to the SMC chip does not transition
for every memory access. It is driven through the CPLD from the CS7
line of the CPU's static memory controller which is optimized to
eliminate unnecessary transitions. Yet, the SMC requires a transition
for every write access. The Sharp website has more information about
the effect this power-conserving feature has on peripheral
interfacing.
The solution is to follow every write access to the SMC chip with an
access to another memory region that will force the CPU to release the
chip select line. It is important to guarantee that this access
forces the CPU off-chip. We map a page of SDRAM as if it were an
uncacheable IO device and read from it after every SMC IO write
operation.
SMC IO
BARRIER IO
Only this sequence is important. It does not matter that there is no
BARRIER IO before the access to the SMC chip because the AEN latch
only needs occurs after the SMC IO write cycle. The routines that
implement this work-around make an additional concession which is to
disable interrupts during the IO sequence. Other hardware devices
(the LogicPD CPLD) have registers in the same physical memory
region as the SMC chip. An interrupt might allow an access to one of
those registers while SMC IO is being performed.
You might be tempted to think that we have to access another device
attached to the static memory controller, but the empirical evidence
indicates that this is not so. Mapping 0x00000000 (flash) and
0xc0000000 (SDRAM) appear to have the same effect. Using SDRAM seems
to be faster. Choosing to access an undecoded memory region is not
desirable as there is no way to know how that chip select will be used
in the future.
README on Implementing Linux for Sharp's KEV7a400
=================================================
This product has been discontinued by Sharp. For the time being, the
partially implemented code remains in the kernel. At some point in
the future, either the code will be finished or it will be removed
completely. This depends primarily on how many of the development
boards are in the field.
README on the LCD Panels
========================
Configuration options for several LCD panels, available from Logic PD,
are included in the kernel source. This README will help you
understand the configuration data and give you some guidance for
adding support for other panels if you wish.
lcd-panels.h
------------
There is no way, at present, to detect which panel is attached to the
system at runtime. Thus the kernel configuration is static. The file
arch/arm/mach-ld7a40x/lcd-panels.h (or similar) defines all of the
panel specific parameters.
It should be possible for this data to be shared among several device
families. The current layout may be insufficiently general, but it is
amenable to improvement.
PIXEL_CLOCK
-----------
The panel data sheets will give a range of acceptable pixel clocks.
The fundamental LCDCLK input frequency is divided down by a PCD
constant in field '.tim2'. It may happen that it is impossible to set
the pixel clock within this range. A clock which is too slow will
tend to flicker. For the highest quality image, set the clock as high
as possible.
MARGINS
-------
These values may be difficult to glean from the panel data sheet. In
the case of the Sharp panels, the upper margin is explicitly called
out as a specific number of lines from the top of the frame. The
other values may not matter as much as the panels tend to
automatically center the image.
Sync Sense
----------
The sense of the hsync and vsync pulses may be called out in the data
sheet. On one panel, the sense of these pulses determine the height
of the visible region on the panel. Most of the Sharp panels use
negative sense sync pulses set by the TIM2_IHS and TIM2_IVS bits in
'.tim2'.
Pel Layout
----------
The Sharp color TFT panels are all configured for 16 bit direct color
modes. The amba-lcd driver sets the pel mode to 565 for 5 bits of
each red and blue and 6 bits of green.
README on Implementing Linux for the Logic PD LPD7A400-10
=========================================================
- CPLD memory mapping
The board designers chose to use high address lines for controlling
access to the CPLD registers. It turns out to be a big waste
because we're using an MMU and must map IO space into virtual
memory. The result is that we have to make a mapping for every
register.
- Serial Console
It may be OK not to use the serial console option if the user passes
the console device name to the kernel. This deserves some exploration.
README on Implementing Linux for the Logic PD LPD7A40X-10
=========================================================
- CPLD memory mapping
The board designers chose to use high address lines for controlling
access to the CPLD registers. It turns out to be a big waste
because we're using an MMU and must map IO space into virtual
memory. The result is that we have to make a mapping for every
register.
- Serial Console
It may be OK not to use the serial console option if the user passes
the console device name to the kernel. This deserves some exploration.
README on the SDRAM Controller for the LH7a40X
==============================================
The standard configuration for the SDRAM controller generates a sparse
memory array. The precise layout is determined by the SDRAM chips. A
default kernel configuration assembles the discontiguous memory
regions into separate memory nodes via the NUMA (Non-Uniform Memory
Architecture) facilities. In this default configuration, the kernel
is forgiving about the precise layout. As long as it is given an
accurate picture of available memory by the bootloader the kernel will
execute correctly.
The SDRC supports a mode where some of the chip select lines are
swapped in order to make SDRAM look like a synchronous ROM. Setting
this bit means that the RAM will present as a contiguous array. Some
programmers prefer this to the discontiguous layout. Be aware that
may be a penalty for this feature where some some configurations of
memory are significantly reduced; i.e. 64MiB of RAM appears as only 32
MiB.
There are a couple of configuration options to override the default
behavior. When the SROMLL bit is set and memory appears as a
contiguous array, there is no reason to support NUMA.
CONFIG_LH7A40X_CONTIGMEM disables NUMA support. When physical memory
is discontiguous, the memory tables are organized such that there are
two banks per nodes with a small gap between them. This layout wastes
some kernel memory for page tables representing non-existent memory.
CONFIG_LH7A40X_ONE_BANK_PER_NODE optimizes the node tables such that
there are no gaps. These options control the low level organization
of the memory management tables in ways that may prevent the kernel
from booting or may cause the kernel to allocated excessively large
page tables. Be warned. Only change these options if you know what
you are doing. The default behavior is a reasonable compromise that
will suit all users.
--
A typical 32MiB system with the default configuration options will
find physical memory managed as follows.
node 0: 0xc0000000 4MiB
0xc1000000 4MiB
node 1: 0xc4000000 4MiB
0xc5000000 4MiB
node 2: 0xc8000000 4MiB
0xc9000000 4MiB
node 3: 0xcc000000 4MiB
0xcd000000 4MiB
Setting CONFIG_LH7A40X_ONE_BANK_PER_NODE will put each bank into a
separate node.
README on the Vectored Interrupt Controller of the LH7A404
==========================================================
The 404 revision of the LH7A40X series comes with two vectored
interrupts controllers. While the kernel does use some of the
features of these devices, it is far from the purpose for which they
were designed.
When this README was written, the implementation of the VICs was in
flux. It is possible that some details, especially with priorities,
will change.
The VIC support code is inspired by routines written by Sharp.
Priority Control
----------------
The significant reason for using the VIC's vectoring is to control
interrupt priorities. There are two tables in
arch/arm/mach-lh7a40x/irq-lh7a404.c that look something like this.
static unsigned char irq_pri_vic1[] = { IRQ_GPIO3INTR, };
static unsigned char irq_pri_vic2[] = {
IRQ_T3UI, IRQ_GPIO7INTR,
IRQ_UART1INTR, IRQ_UART2INTR, IRQ_UART3INTR, };
The initialization code reads these tables and inserts a vector
address and enable for each indicated IRQ. Vectored interrupts have
higher priority than non-vectored interrupts. So, on VIC1,
IRQ_GPIO3INTR will be served before any other non-FIQ interrupt. Due
to the way that the vectoring works, IRQ_T3UI is the next highest
priority followed by the other vectored interrupts on VIC2. After
that, the non-vectored interrupts are scanned in VIC1 then in VIC2.
ISR
---
The interrupt service routine macro get_irqnr() in
arch/arm/kernel/entry-armv.S scans the VICs for the next active
interrupt. The vectoring makes this code somewhat larger than it was
before using vectoring (refer to the LH7A400 implementation). In the
case where an interrupt is vectored, the implementation will tend to
be faster than the non-vectored version. However, the worst-case path
is longer.
It is worth noting that at present, there is no need to read
VIC2_VECTADDR because the register appears to be shared between the
controllers. The code is written such that if this changes, it ought
to still work properly.
Vector Addresses
----------------
The proper use of the vectoring hardware would jump to the ISR
specified by the vectoring address. Linux isn't structured to take
advantage of this feature, though it might be possible to change
things to support it.
In this implementation, the vectoring address is used to speed the
search for the active IRQ. The address is coded such that the lowest
6 bits store the IRQ number for vectored interrupts. These numbers
correspond to the bits in the interrupt status registers. IRQ zero is
the lowest interrupt bit in VIC1. IRQ 32 is the lowest interrupt bit
in VIC2. Because zero is a valid IRQ number and because we cannot
detect whether or not there is a valid vectoring address if that
address is zero, the eigth bit (0x100) is set for vectored interrupts.
The address for IRQ 0x18 (VIC2) is 0x118. Only the ninth bit is set
for the default handler on VIC1 and only the tenth bit is set for the
default handler on VIC2.
In other words.
0x000 - no active interrupt
0x1ii - vectored interrupt 0xii
0x2xx - unvectored interrupt on VIC1 (xx is don't care)
0x4xx - unvectored interrupt on VIC2 (xx is don't care)
......@@ -795,17 +795,6 @@ config ARCH_TCC_926
help
Support for Telechips TCC ARM926-based systems.
config ARCH_LH7A40X
bool "Sharp LH7A40X"
select CPU_ARM922T
select ARCH_SPARSEMEM_ENABLE if !LH7A40X_CONTIGMEM
select ARCH_USES_GETTIMEOFFSET
help
Say Y here for systems based on one of the Sharp LH7A40X
System on a Chip processors. These CPUs include an ARM922T
core with a wide array of integrated devices for
hand-held and low-power applications.
config ARCH_U300
bool "ST-Ericsson U300 Series"
depends on MMU
......@@ -922,8 +911,6 @@ source "arch/arm/mach-kirkwood/Kconfig"
source "arch/arm/mach-ks8695/Kconfig"
source "arch/arm/mach-lh7a40x/Kconfig"
source "arch/arm/mach-loki/Kconfig"
source "arch/arm/mach-lpc32xx/Kconfig"
......
......@@ -146,7 +146,6 @@ machine-$(CONFIG_ARCH_IXP23XX) := ixp23xx
machine-$(CONFIG_ARCH_IXP4XX) := ixp4xx
machine-$(CONFIG_ARCH_KIRKWOOD) := kirkwood
machine-$(CONFIG_ARCH_KS8695) := ks8695
machine-$(CONFIG_ARCH_LH7A40X) := lh7a40x
machine-$(CONFIG_ARCH_LOKI) := loki
machine-$(CONFIG_ARCH_LPC32XX) := lpc32xx
machine-$(CONFIG_ARCH_MMP) := mmp
......
CONFIG_EXPERIMENTAL=y
# CONFIG_SWAP is not set
CONFIG_SYSVIPC=y
CONFIG_IKCONFIG=y
CONFIG_LOG_BUF_SHIFT=14
CONFIG_EXPERT=y
# CONFIG_HOTPLUG is not set
# CONFIG_EPOLL is not set
# CONFIG_IOSCHED_DEADLINE is not set
CONFIG_ARCH_LH7A40X=y
CONFIG_MACH_LPD7A400=y
CONFIG_PREEMPT=y
CONFIG_ZBOOT_ROM_TEXT=0x0
CONFIG_ZBOOT_ROM_BSS=0x0
CONFIG_FPE_NWFPE=y
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
CONFIG_INET=y
CONFIG_IP_PNP=y
CONFIG_IP_PNP_DHCP=y
CONFIG_IP_PNP_BOOTP=y
CONFIG_IP_PNP_RARP=y
# CONFIG_IPV6 is not set
CONFIG_MTD=y
CONFIG_MTD_PARTITIONS=y
CONFIG_MTD_CMDLINE_PARTS=y
CONFIG_MTD_CHAR=y
CONFIG_MTD_BLOCK=y
CONFIG_MTD_CFI=y
CONFIG_MTD_CFI_INTELEXT=y
CONFIG_MTD_PHYSMAP=y
CONFIG_BLK_DEV_LOOP=y
CONFIG_IDE=y
CONFIG_SCSI=y
# CONFIG_SCSI_PROC_FS is not set
CONFIG_NETDEVICES=y
CONFIG_NET_ETHERNET=y
CONFIG_SMC91X=y
# CONFIG_INPUT_MOUSEDEV is not set
CONFIG_INPUT_EVDEV=y
# CONFIG_INPUT_KEYBOARD is not set
# CONFIG_INPUT_MOUSE is not set
CONFIG_INPUT_TOUCHSCREEN=y
# CONFIG_SERIO is not set
CONFIG_SERIAL_LH7A40X=y
CONFIG_SERIAL_LH7A40X_CONSOLE=y
CONFIG_FB=y
# CONFIG_VGA_CONSOLE is not set
CONFIG_SOUND=y
CONFIG_SND=y
CONFIG_SND_MIXER_OSS=y
CONFIG_SND_PCM_OSS=y
CONFIG_EXT2_FS=y
CONFIG_EXT3_FS=y
CONFIG_VFAT_FS=y
CONFIG_TMPFS=y
CONFIG_JFFS2_FS=y
CONFIG_CRAMFS=y
CONFIG_NFS_FS=y
CONFIG_NFS_V3=y
CONFIG_ROOT_NFS=y
CONFIG_PARTITION_ADVANCED=y
CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_INFO=y
CONFIG_DEBUG_USER=y
CONFIG_DEBUG_ERRORS=y
CONFIG_EXPERIMENTAL=y
# CONFIG_SWAP is not set
CONFIG_SYSVIPC=y
CONFIG_IKCONFIG=y
CONFIG_LOG_BUF_SHIFT=16
CONFIG_EXPERT=y
# CONFIG_HOTPLUG is not set
# CONFIG_EPOLL is not set
CONFIG_SLAB=y
# CONFIG_IOSCHED_DEADLINE is not set
CONFIG_ARCH_LH7A40X=y
CONFIG_MACH_LPD7A404=y
CONFIG_PREEMPT=y
CONFIG_DISCONTIGMEM_MANUAL=y
CONFIG_ZBOOT_ROM_TEXT=0x0
CONFIG_ZBOOT_ROM_BSS=0x0
CONFIG_FPE_NWFPE=y
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
CONFIG_INET=y
CONFIG_IP_PNP=y
CONFIG_IP_PNP_DHCP=y
CONFIG_IP_PNP_BOOTP=y
CONFIG_IP_PNP_RARP=y
# CONFIG_IPV6 is not set
CONFIG_MTD=y
CONFIG_MTD_PARTITIONS=y
CONFIG_MTD_CMDLINE_PARTS=y
CONFIG_MTD_CHAR=y
CONFIG_MTD_BLOCK=y
CONFIG_MTD_CFI=y
CONFIG_MTD_CFI_INTELEXT=y
CONFIG_MTD_PHYSMAP=y
CONFIG_BLK_DEV_LOOP=y
CONFIG_IDE=y
CONFIG_SCSI=y
# CONFIG_SCSI_PROC_FS is not set
CONFIG_NETDEVICES=y
CONFIG_NET_ETHERNET=y
CONFIG_SMC91X=y
# CONFIG_INPUT_MOUSEDEV_PSAUX is not set
CONFIG_INPUT_EVDEV=y
# CONFIG_INPUT_KEYBOARD is not set
# CONFIG_INPUT_MOUSE is not set
CONFIG_INPUT_TOUCHSCREEN=y
# CONFIG_SERIO is not set
CONFIG_SERIAL_LH7A40X=y
CONFIG_SERIAL_LH7A40X_CONSOLE=y
CONFIG_FB=y
# CONFIG_VGA_CONSOLE is not set
CONFIG_SOUND=y
CONFIG_SND=y
CONFIG_SND_MIXER_OSS=y
CONFIG_SND_PCM_OSS=y
CONFIG_USB=y
CONFIG_USB_DEVICEFS=y
CONFIG_USB_MON=y
CONFIG_USB_OHCI_HCD=y
CONFIG_USB_STORAGE=y
CONFIG_USB_STORAGE_DEBUG=y
CONFIG_USB_STORAGE_DATAFAB=y
CONFIG_USB_GADGET=y
CONFIG_USB_ZERO=y
CONFIG_EXT2_FS=y
CONFIG_EXT3_FS=y
CONFIG_INOTIFY=y
CONFIG_VFAT_FS=y
CONFIG_TMPFS=y
CONFIG_JFFS2_FS=y
CONFIG_CRAMFS=y
CONFIG_NFS_FS=y
CONFIG_NFS_V3=y
CONFIG_ROOT_NFS=y
CONFIG_PARTITION_ADVANCED=y
CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_INFO=y
CONFIG_DEBUG_USER=y
CONFIG_DEBUG_ERRORS=y
......@@ -192,11 +192,7 @@ static struct tagtable __tagtable_##fn __tag = { tag, fn }
/*
* Memory map description
*/
#ifdef CONFIG_ARCH_LH7A40X
# define NR_BANKS 16
#else
# define NR_BANKS 8
#endif
#define NR_BANKS 8
struct membank {
unsigned long start;
......
if ARCH_LH7A40X
menu "LH7A40X Implementations"
config MACH_KEV7A400
bool "KEV7A400"
select ARCH_LH7A400
help
Say Y here if you are using the Sharp KEV7A400 development
board. This hardware is discontinued, so I'd be very
surprised if you wanted this option.
config MACH_LPD7A400
bool "LPD7A400 Card Engine"
select ARCH_LH7A400
# select IDE_POLL
# select HAS_TOUCHSCREEN_ADS7843_LH7
help
Say Y here if you are using Logic Product Development's
LPD7A400 CardEngine. For the time being, the LPD7A400 and
LPD7A404 options are mutually exclusive.
config MACH_LPD7A404
bool "LPD7A404 Card Engine"
select ARCH_LH7A404
# select IDE_POLL
# select HAS_TOUCHSCREEN_ADC_LH7
help
Say Y here if you are using Logic Product Development's
LPD7A404 CardEngine. For the time being, the LPD7A400 and
LPD7A404 options are mutually exclusive.
config ARCH_LH7A400
bool
config ARCH_LH7A404
bool
config LPD7A40X_CPLD_SSP
bool
config LH7A40X_CONTIGMEM
bool "Disable NUMA/SparseMEM Support"
help
Say Y here if your bootloader sets the SROMLL bit(s) in
the SDRAM controller, organizing memory as a contiguous
array. This option will disable sparse memory support
and force the kernel to manage all memory in one node.
Setting this option incorrectly may prevent the kernel