Some devices using the MVTWSI driver have the option to run at speeds
faster than Standard Mode (100kHZ). On the Armada 38x controllers, this
is actually necessary, since due to erratum FE-8471889, a timing
violation concerning repeated starts prevents the controller from
working correctly in Standard Mode. One of the workarounds recommended
in the erratum is to set the bus to Fast Mode (400kHZ) operation and
ensure all connected devices are set to Fast Mode.
In the current version of the driver, however, the delay times are
hard-coded to 10ms, corresponding to Standard Mode operation. To take
full advantage of the faster modes, we would need to either keep the
currently configured I2C speed in a globally accessible variable, or
pass it to the necessary functions as a parameter. For DM, the first
option is not a problem, and we can simply keep the speed in the private
data of the driver. For the legacy interface, however, we would need to
introduce a static variable, which would cause problems with boots from
NOR flashes; see commit d6b7757 "i2c: mvtwsi: Eliminate
twsi_control_flags."
As to not clutter the interface with yet another parameter, we therefore
keep the default 10ms delays for the legacy functions.
In DM mode, we make the delay time dependant on the frequency to allow
taking full advantage of faster modes of operation (tested with up to
1MHZ frequency on Armada MV88F6820).
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
Zero-length offsets are not properly handled by the driver. When a read
operation with a zero-length offset is started, a START condition is
asserted, and since no offset bytes are transferred, a repeated START is
issued immediately after, which confuses the controller.
To fix this, we send the first START only if any address bytes need to
be sent, and keep track of the expected start status accordingly.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
This patch adds the necessary functions and Kconfig entry to make the
MVTWSI I2C driver compatible with the driver model.
A possible device tree entry might look like this:
i2c@11100 {
compatible = "marvell,mv64xxx-i2c";
reg = <0x11000 0x20>;
clock-frequency = <100000>;
u-boot,i2c-slave-addr = <0x0>;
};
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
The length of the address parameter of the __twsi_i2c_read and
__twsi_i2c_write functions is fixed to four bytes.
As a final step in the preparation of the DM conversion, we make the
length of this parameter variable by turning it into an array of bytes,
and convert the 32 bit value that's passed to the legacy functions into
a four-byte-array on the fly.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
To be able to use the compatibility layer from the DM functions, we
factor the adap parameter out of all functions, and pass the actual
register base instead.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
To prepare for the DM conversion, we add a layer of compatibility
functions to be used by both the legacy and the DM functions.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
Since some additional parameters will be added in the course of this
patch series (especially with the addition of DM support), we replace
the longer "unsigned int" declarations with "uint" declarations to keep
the parameter lists more readable.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
The twsi_stop function contains a parameter "status," which is used to
pass in the current exit status of the function calling twsi_stop, and
either return this status unchanged if it indicates an error, or return
twsi_stop's exit status if it does not indicate an error.
While not massively complicated, this adds another purpose to the
twsi_stop function, which should have the sole purpose of asserting a
STOP condition on the bus (and not manage the exit status of its
caller).
Therefore, we move the exit status management into the caller functions
by introducing a "stop_status" variable and returning either the status
before the twsi_stop call (kept in the "status" variable), or the status
from the twsi_stop call, depending on which indicates an error.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
Due to breaking boots from NOR flashes, commit d6b7757 ("i2c: mvtwsi:
Eliminate twsi_control_flags") removed the static global
twsi_control_flags variable, which kept a set of default flags that were
always or'd to the control register when writing. It was replaced with a
flags parameter, which was passed around between the functions that
needed it.
Since the twsi_control_flags variable was used just for the purposes of
a) setting the MVTWSI_CONTROL_TWSIEN on every control register write,
and
b) setting the MVTWSI_CONTROL_ACK from twsi_i2c_read if needed,
anyway, the added overhead of another variable being passed around is no
longer justified, and we are better off implementing this flag setting
logic locally in the functions that actually write to the control
register.
Therefore, this patch sets MVTWSI_CONTROL_TWSIEN on every control
register write, replaces the twsi_i2c_read's flags parameter with a
ack_flag parameter, which tells the function whether to acknowledge the
read or not, and removes every other instance of the flags variable.
This has the added benefit that now every notion of "global default
flags" is gone, and it's much easier to see which control flags are
actually set at which point in time.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
This patch fixes only comments/documentation: Streamline capitalization
and improve grammar/punctuation.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
Convert groups of logically connected preprocessor defines into proper
enums, one macro into an inline function, and add documentation
to/extend existing documentation of these items.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
This patch fixes seven style violations: Six superfluous spaces after
casts, and one logical continuation violation.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
In a system where the initial u-boot location is genuinely NOR flash (as
opposed to RAM or a cache-line setup by a pre-bootloader) writes to the
data section are problematic. At best these writes have no effect, at
worst they put the flash memory into a status mode which changes the
executable code underneath us.
Pass around a stack variable from the top of the twsi i2c driver to
avoid writing to global data.
Signed-off-by: Chris Packham <judge.packham@gmail.com>
"Fix mvtwsi not working on sun6i and newer sunxi SoCs" includes the following:
@@ -189,7 +200,8 @@ static int twsi_start(struct i2c_adapter *adap, int expected_status)
/* globally set TWSIEN in case it was not */
twsi_control_flags |= MVTWSI_CONTROL_TWSIEN;
/* assert START */
- writel(twsi_control_flags | MVTWSI_CONTROL_START, &twsi->control);
+ twsi_control_flags |= MVTWSI_CONTROL_START | MVTWSI_CONTROL_CLEAR_IFLG;
+ writel(twsi_control_flags, &twsi->control);
/* wait for controller to process START */
return twsi_wait(adap, expected_status);
}
The modification of twsi_control_flags done here was introduced while
merging to fix a line > 80 chars, but twsi_control_flags is a global variable
and should not be modified like this here, this commit fixes this, restoring
mvtwsi functionality.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jelle van der Waa <jelle@vdwaa.nl>
[hdegoede@redhat.com: Minor cleanups]
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
applied with fixing 2 checkpatch warnings:
WARNING: please, no space before tabs
Signed-off-by: Heiko Schocher <hs@denx.de>
On sun6i and newer IFLG is a write-clear bit which is cleared by writing 1,
rather then a normal r/w bit which is cleared by writing 0.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
applied with fixing 3 checkpatch warnings
in drivers/i2c/mvtwsi.c:
WARNING: line over 80 characters
ERROR: code indent should use tabs where possible
WARNING: please, no spaces at the start of a line
Signed-off-by: Heiko Schocher <hs@denx.de>
Until now, the SoC selection for the ARCH_MVEBU platforms has been done
in the config header. Using CONFIG_ARMADA_XP in a non-clear way. As
it needed to get selected for AXP and A38x based boards. This patch
now changes this to move the SoC selection to Kconfig. And also
uses CONFIG_ARCH_MVEBU as a common define for both AXP and A38x.
This makes things a bit clearer - especially for new board additions.
Additionally the defines CONFIG_SYS_MVEBU_DDR_AXP and
CONFIG_SYS_MVEBU_DDR_A38X are replaced with the already available
CONFIG_ARMADA_38X and CONFIG_ARMADA_XP.
And CONFIG_DDR3 is removed, as its not referenced anywhere.
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Luka Perkov <luka.perkov@sartura.hr>
Orion5x, Kirkwood and Armada XP platforms come with a single TWSI (I2C) MVTWSI
controller. However, other platforms using MVTWSI may come with more: this is
the case on Allwinner (sunxi) platforms, where up to 4 controllers can be found
on the same chip.
Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Acked-by: Heiko Schocher <hs@denx.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The current implementation for baudrate calculation is incorrect.
This part from the formula:
"2 ^ (n + 1)" is not equivalent to (1 << n) but to (2 << n)!
This patch fixes this and moves this calculation to a function instead of using a macro.
This new function is taken from the Linux kernel.
This was detected and tested on the Marvell Armada A38x DB-88F6820-GP eval board.
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Prafulla Wadaskar <prafulla@marvell.com>
Cc: Luka Perkov <luka.perkov@sartura.hr>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Heiko Schocher <hs@denx.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
To support the Armada XP SoC, we just need to include the correct header.
Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Heiko Schocher <hs@denx.de>
Tested-by: Luka Perkov <luka@openwrt.org>
This move makes is possible to use this header not only from kirkwood
platforms but from all Marvell mvebu platforms.
Signed-off-by: Stefan Roese <sr@denx.de>
Tested-by: Luka Perkov <luka@openwrt.org>
Acked-by: Prafulla Wadaskar <prafulla@marvell.com>
Add support for the i2c controller found on all Allwinner sunxi SoCs,
this is the same controller as found on the Marvell orion5x and kirkwood
SoC families, with a slightly different register layout, so this patch uses
the existing mvtwsi code.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
Acked-By: Prafulla Wadaskar <prafulla@marvell.com>
Acked-by: Heiko Schocher <hs@denx.de>
[ ijc -- updated u-boot-spl-fel.lds ]
Note this has only been tested on Allwinner sunxi devices (support for which
gets introduced by a later patch).
The kirkwood changes have been compile tested using the wireless_space board
config, the orion5x changes have been compile tested using the edminiv2 board
config.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Heiko Schocher <hs@denx.de>
These are used only once, so their is no need to have them global.
This also stops mvtwsi from using any bss vars making it easier to use
before dram init (to talk to the pmic to set the dram voltage).
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The TWSI_FREQUENCY macro was wrong in 2 ways:
1) It was casting the result of the calculations to an u8, while i2c clk
rates are often >= 100Khz which won't fit in a u8, drop the cast.
2) It had an extra factor of 2 in the divider which neither the datasheet nor
the Linux driver have.
The comment for the default value was wrongly saying that m lives in
bits 4-7, while in reality it is in bits 3-6, as can be seen from the correct
shift by 3 used in i2c_init().
While at it remove the unused twsi_actual_speed variable.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
This rewrite of the mvtwsi driver is 25% smaller and much
faster and simpler than the previous code.
Signed-off-by: Albert Aribaud <albert.aribaud@free.fr>
Acked-by: Prafulla Wadaskar<prafulla@marvell.com>
Acked-by: Heiko Schocher<hs@denx.de>
This driver is not kirkwood-specific and can also be used
e.g. by orion5x. Rename to a SoC-neutral name.
Signed-off-by: Albert Aribaud <albert.aribaud@free.fr>
Acked-by: Prafulla Wadaskar<prafulla@marvell.com>
Acked-by: Heiko Schocher<hs@denx.de>
2010-08-30 14:10:23 +02:00
Renamed from drivers/i2c/kirkwood_i2c.c (Browse further)
