Before calling __dw_i2c_set_bus_speed(),
the I2C could already be set as ether enable or disable,
we should restore the original setting instead of enable i2c anyway.
This patch fix a bug happened in init function:
__dw_i2c_init(){
/* Disable i2c */
...
__dw_i2c_set_bus_speed(i2c_base, NULL, speed);
writel(slaveaddr, &i2c_base->ic_sar);
/* Enable i2c */
}
In this case, enable i2c inside __dw_i2c_set_bus_speed() function
will cause ic_sar write fail.
Signed-off-by: Jun Chen <ptchentw@gmail.com>
This avoids useless loops inside the I2C timing algorithm.
Actually, we support only one possible solution per prescaler value.
So after finding a solution with a prescaler, the algorithm can
switch directly to the next prescaler value.
Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
Reviewed-by: Patrick DELAUNAY <patrick.delaunay@st.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
It conforms with Reference Manual I2C timing section.
Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
Reviewed-by: Patrick DELAUNAY <patrick.delaunay@st.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Since the IHS I2C driver want upstream, the surrounding infrastructure
has changed quite a bit (notably, the fpgamap driver was replaced with a
regmap driver).
Update the driver to work with these changes.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Heiko Schocher <hs@denx.de>
These options only apply when not using DM_I2C. When using device
trees, the dt will enable and control the speeds of the I2C
controller(s) and these configuration options have no effect.
So disable them in DM_I2C mode. Otherwise they show up as decoys, and
make it look like one is enabling I2C controllers and setting the speed
when really it's doing nothing.
However, a system using a SPL build will not use DM_I2C in the SPL, even
if DM_I2C is enabled for the main u-boot. And so the SPL might use the
kconfig based I2C speed controls while the main u-boot does not.
Cc: Sriram Dash <sriram.dash@nxp.com>
Cc: Priyanka Jain <priyanka.jain@nxp.com>
Cc: Heiko Schocher <hs@denx.de>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
This is an old driver that supports both device mapped and non-mapped
mode, and covers a wide range of hardware. It's hard to change without
risking breaking something. I have to tried to be exceedingly detailed
in this patch, so please excuse the length of the commit essay that
follows.
In device mapped mode the I2C xfer function does not handle plain read,
and some other, transfers correctly.
What it can't handle are transactions that:
Start with a read, or,
Have a write followed by a read, or,
Have more than one read in a row.
The common I2C/SMBUS read register and write register transactions
always start with a write, followed by a write or a read, and then end.
These work, so the bug is not apparent for most I2C slaves that only use
these common xfer forms.
The existing xfer loop initializes by sending the chip address in write
mode after it deals with bus arbitration and master setup. When
processing each message, if the next message will be a read, it sends a
repeated start followed by the chip address in read mode after the
current message.
Obviously, this does not work if the first message is a read, as the
chip is always addressed in write mode initially by i2c_init_transfer().
A write following a read does not work because the repeated start is
only sent when the next message is a read. There is no logic to send it
when the current message is a read and next is write. It should be sent
every time the bus changes direction.
The ability to use a plain read was added to this driver in
commit 2feec4eafd ("imx: mxc_i2c: tweak the i2c transfer method"),
but this applied only the non-DM code path.
This patch fixes the DM code path. The xfer function will call
i2c_init_transfer() with an alen of -1 to avoid sending the chip
address. The same way the non-DM code achieves this. The xfer
function's message loop will send the address and mode before each
message if the bus changes direction, and on the first message.
When reading data, the master hardware is one byte ahead of what we
receive. I.e., reading a byte from the data register returns a byte
*already received* by the master, and causes the master to start the RX
of the *next* byte. Therefor, before we read the final byte of a
message, we must tell the master what to do next. I add a "last" flag
to i2c_read_data() to tell it if the message is to be followed by a stop
or a repeated start. When last == true it acts exactly as before.
The non-DM code can only create an xfer where the read, if any, is the
final message of the xfer. And so the only callsite of i2c_read_data()
in the non-DM code has the "last" parameter as true. Therefore, this
change has no effect on the non-DM code. As all other changes are in
the DM xfer function, which is not even compiled in non-DM code, I am
confident that this patch has no effect on boards not using I2C_DM.
This greatly reduces the range of hardware that could be affected.
For DM boards, I have verified every transaction the "i2c" command can
create on a scope and they are all exactly as they are supposed to be.
I also tested write->read->write, which isn't possible with the i2c
command, and it works as well. I didn't fix multiple reads in a row, as
it's a lot more invasive and obviously no one has every wanted them
since they've never worked. It didn't seem like the extra complexity
was justified to support something no one uses.
Cc: Nandor Han <nandor.han@ge.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Breno Matheus Lima <brenomatheus@gmail.com>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
It is not very clear how these work in relation to the exact I2C xfers
they produce. In paticular, the address length is somewhat overloaded
in the read method. Clearly document the existing behavior. Maybe this
will help the next person who needs to work on this driver and not break
non-DM boards.
Cc: Nandor Han <nandor.han@ge.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Breno Matheus Lima <brenomatheus@gmail.com>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
The twsi_wait function reads the control register for interrupt flag,
and if interrupt flag is present, it immediately reads status register.
On our device this sometimes causes bad value being read from status
register, as if the value was not yet updated.
My theory is that the controller does approximately this:
1. sets interrupt flag in control register,
2. sets the value of status register,
3. causes an interrupt
In U-Boot we do not use interrupts, so I think that it is possible that
sometimes the status register in the twsi_wait function is read between
points 1 and 2.
The bug does not appear if I add a small delay before reading status
register.
Wait 100ns (which in U-Boot currently means 1 us, because ndelay(i)
function calls udelay(DIV_ROUND_UP(i, 1000))) before reading the status
register.
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Stefan Roese <sr@denx.de>
Cc: Mario Six <mario.six@gdsys.cc>
Cc: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Stefan Roese <sr@denx.de>
Rockchip use 'arch-rockchip' instead of arch-$(SOC) as common
header file path, so that we can get the correct path directly.
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Using this driver on socfpga gen5 with DM_I2C enabled leads to a data abort
as the 'i2c' reset property cannot be found (the gen5 dtsi does not provide
reset-names).
The actual bug was to check 'if (&priv->reset_ctl)', which is never false.
While at it, convert the driver to use 'reset_get_bulk' instead of looking
at a specific named reset and also make it release the reset on driver
remove before starting the OS.
Fixes: 622597dee4 ("i2c: designware: add reset ctrl to driver")
Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
The chip_desc.enable field is used only for muxes, not for switches.
Document it and remove the unused values.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Heiko Schocher <hs@denx.de>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Heiko Schocher<hs@denx.de>
The Kconfig help has not been updated while adding PCA9547 and PCA9646.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Heiko Schocher<hs@denx.de>
The 'u-boot,i2c-transaction-bytes' device tree property provides
information regarding number of bytes transferred by a device in a
single transaction.
This change is necessary to avoid hanging devices after soft reset.
One notable example is communication with MC34708 device:
1. Reset when communicating with MC34708 via I2C.
2. The u-boot (after reboot -f) tries to setup the I2C and then calls
force_idle_bus. In the same time MC34708 still has some data to be sent
(as it transfers data in 24 bits chunks).
3. The force_idle_bus() is not able to make the bus idle as 8 SCL
clocks may be not enough to have the full transmission.
4. We end up with I2C inconsistency with MC34708.
This PMIC device requires 24+ SCL cycles to make finish any pending I2C
transmission.
Signed-off-by: Lukasz Majewski <lukma@denx.de>
This patch add support for I2C controller in Meson-AXG SoC,
Due to the IP changes between I2C controller, we need to introduce
a compatible data to make the divider factor configurable.
backport from linux:
931b18e92cd0 ("2c: meson: add configurable divider factors")
Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
This patch fixes below warnings found with checker tool.
The variable len in i2c_msg struct is of unsigned type
and it is received as recv_count which is unsigned type
but it is checked with < 0 which is always false, hence
removed it.
The local variable curr_recv_count is declared as signed
type and compared aginst unsigned recv_count which is
incorrect. This is fixed by declaring it as unsigned type.
drivers/i2c/i2c-cdns.c: In function ‘cdns_i2c_read_data’:
drivers/i2c/i2c-cdns.c:317:18: warning: comparison of
unsigned expression < 0 is always false [-Wtype-limits]
if ((recv_count < 0))
^
drivers/i2c/i2c-cdns.c:340:24: warning: comparison of
integer expressions of different signedness:
‘u32’ {aka ‘unsigned int’} and ‘int’ [-Wsign-compare]
updatetx = recv_count > curr_recv_count;
^
drivers/i2c/i2c-cdns.c:361:39: warning: comparison of
integer expressions of different signedness:
‘u32’ {aka ‘unsigned int’} and ‘int’ [-Wsign-compare]
while (readl(®s->transfer_size) !=
Signed-off-by: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Cosmetic change. Any call to the recover function would need to do the
same check afterwards, so it's sensible to make it part of the function.
Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
It needs to be done for both reads and writes, so do it at rcar_i2c_xfer
to avoid duplication.
Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Fix rcar_i2c_xfer return value, previously it was always returning
-EREMOTEIO when dealing with errors from calls to the read/write
functions.
Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Do the reset before clearing the MSR, otherwise it may result in a read
or write operation instead if the start condition is repeated.
Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Document the meaning of macros related to registers and values to be
written to them.
Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Setting up the delay only needs to be done once; move it to
rcar_i2c_set_speed so it's done at initialization time.
Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
This patch adds support for handling arbitration lost
in case of multi master mode. When an arbitration lost
is detected, it retries for 10 times before failing.
Signed-off-by: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
The arbitration lost interrupt was not getting cleared
while clearing interrupts. This patch fixes this by adding
arbitration lost interrupt as well during clear. This patch
also removes hardcoded value and defined a macro for it.
Signed-off-by: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Add support for R-Car Gen3 SoCs into the driver, which encompases
the Gen3 SoC extra timing register handling and 64bit build fixes.
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Heiko Schocher <hs@denx.de>
Reviewed-by: Heiko Schocher <hs@denx.de>
Read ICSR only once to avoid missing interrupts. This happens on R8A7791
Porter during reset, when reading the PMIC register 0x13, which may fail
sometimes because of the missed DTE interrupt.
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
Migrate SYS_I2C_TEGRA from headers to Kconfig
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Cc: Tom Warren <twarren@nvidia.com>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Cc: Peter.Chubb@data61.csiro.au
Cc: Lucas Stach <dev@lynxeye.de>
Cc: Stefan Agner <stefan.agner@toradex.com>
Cc: Alban Bedel <alban.bedel@avionic-design.de>
Cc: Allen Martin <amartin@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
At present this driver does not check whether it is able to actually
communicate with the I2C controller. It prints a timeout message but still
considers the probe to be successful.
To fix this, add some checking that the init succeeds.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
This driver is replaced by drivers/i2c/i2c-cdns.c DM based driver.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Heiko Schocher <hs@denx.de>
For !DM case busses are listed as
ZynqMP> i2c bus
Bus 0: zynq_0
Bus 1: zynq_0->PCA9544A@0x75:0
Bus 2: zynq_0->PCA9544A@0x75:1
Bus 3: zynq_0->PCA9544A@0x75:2
Bus 4: zynq_1
Bus 5: zynq_1->PCA9548@0x74:0
Bus 6: zynq_1->PCA9548@0x74:1
Bus 7: zynq_1->PCA9548@0x74:2
Bus 8: zynq_1->PCA9548@0x74:3
Bus 9: zynq_1->PCA9548@0x74:4
Bus 10: zynq_1->PCA9548@0x75:0
Bus 11: zynq_1->PCA9548@0x75:1
Bus 12: zynq_1->PCA9548@0x75:2
Bus 13: zynq_1->PCA9548@0x75:3
Bus 14: zynq_1->PCA9548@0x75:4
Bus 15: zynq_1->PCA9548@0x75:5
Bus 16: zynq_1->PCA9548@0x75:6
Bus 17: zynq_1->PCA9548@0x75:7
where is exactly describing i2c bus topology.
By moving to DM case i2c mux buses are using names from DT and because
i2c-muxes describing sub busses with the same names like i2c@0, etc it
is hard to identify which bus is where.
Linux is adding topology information to i2c-mux busses to identify them
better.
This patch is doing the same and composing bus name with topology
information.
When patch is applied with topology information on zcu102-revA.
ZynqMP> i2c bus
Bus 0: i2c@ff020000
20: gpio@20, offset len 1, flags 0
21: gpio@21, offset len 1, flags 0
75: i2c-mux@75, offset len 1, flags 0
Bus 2: i2c@ff020000->i2c-mux@75->i2c@0
Bus 3: i2c@ff020000->i2c-mux@75->i2c@1
Bus 4: i2c@ff020000->i2c-mux@75->i2c@2
Bus 1: i2c@ff030000 (active 1)
74: i2c-mux@74, offset len 1, flags 0
75: i2c-mux@75, offset len 1, flags 0
Bus 5: i2c@ff030000->i2c-mux@74->i2c@0 (active 5)
54: eeprom@54, offset len 1, flags 0
Bus 6: i2c@ff030000->i2c-mux@74->i2c@1
Bus 7: i2c@ff030000->i2c-mux@74->i2c@2
Bus 8: i2c@ff030000->i2c-mux@74->i2c@3
Bus 9: i2c@ff030000->i2c-mux@74->i2c@4
Bus 10: i2c@ff030000->i2c-mux@75->i2c@0
Bus 11: i2c@ff030000->i2c-mux@75->i2c@1
Bus 12: i2c@ff030000->i2c-mux@75->i2c@2
Bus 13: i2c@ff030000->i2c-mux@75->i2c@3
Bus 14: i2c@ff030000->i2c-mux@75->i2c@4
Bus 15: i2c@ff030000->i2c-mux@75->i2c@5
Bus 16: i2c@ff030000->i2c-mux@75->i2c@6
Bus 17: i2c@ff030000->i2c-mux@75->i2c@7
Behavior before the patch is applied.
ZynqMP> i2c bus
Bus 0: i2c@ff020000
20: gpio@20, offset len 1, flags 0
21: gpio@21, offset len 1, flags 0
75: i2c-mux@75, offset len 1, flags 0
Bus 2: i2c@0
Bus 3: i2c@1
Bus 4: i2c@2
Bus 1: i2c@ff030000 (active 1)
74: i2c-mux@74, offset len 1, flags 0
75: i2c-mux@75, offset len 1, flags 0
Bus 5: i2c@0 (active 5)
54: eeprom@54, offset len 1, flags 0
Bus 6: i2c@1
Bus 7: i2c@2
Bus 8: i2c@3
Bus 9: i2c@4
Bus 10: i2c@0
Bus 11: i2c@1
Bus 12: i2c@2
Bus 13: i2c@3
Bus 14: i2c@4
Bus 15: i2c@5
Bus 16: i2c@6
Bus 17: i2c@7
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
For i2c controllers which are missing alias in DT there is no req_seq
setup. This function is setting up proper ID based on highest found
alias ID.
On zcu102 this is the behavior when patch is applied.
ZynqMP> i2c bus
Bus 0: i2c@ff020000
20: gpio@20, offset len 1, flags 0
21: gpio@21, offset len 1, flags 0
75: i2c-mux@75, offset len 1, flags 0
Bus 2: i2c@0
Bus 3: i2c@1
Bus 4: i2c@2
Bus 1: i2c@ff030000 (active 1)
74: i2c-mux@74, offset len 1, flags 0
75: i2c-mux@75, offset len 1, flags 0
Bus 5: i2c@0 (active 5)
54: eeprom@54, offset len 1, flags 0
Bus 6: i2c@1
Bus 7: i2c@2
Bus 8: i2c@3
Bus 9: i2c@4
Bus 10: i2c@0
Bus 11: i2c@1
Bus 12: i2c@2
Bus 13: i2c@3
Bus 14: i2c@4
Bus 15: i2c@5
Bus 16: i2c@6
Bus 17: i2c@7
Before this patch applied (controllers have -1 ID)
ZynqMP> i2c bus
Bus 0: i2c@ff020000
20: gpio@20, offset len 1, flags 0
21: gpio@21, offset len 1, flags 0
75: i2c-mux@75, offset len 1, flags 0
Bus -1: i2c@0
Bus -1: i2c@1
Bus -1: i2c@2
Bus 1: i2c@ff030000 (active 1)
74: i2c-mux@74, offset len 1, flags 0
75: i2c-mux@75, offset len 1, flags 0
Bus -1: i2c@0 (active 0)
54: eeprom@54, offset len 1, flags 0
Bus -1: i2c@1
Bus -1: i2c@2
Bus -1: i2c@3
Bus -1: i2c@4
Bus -1: i2c@0
Bus -1: i2c@1
Bus -1: i2c@2
Bus -1: i2c@3
Bus -1: i2c@4
Bus -1: i2c@5
Bus -1: i2c@6
Bus -1: i2c@7
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
There is a need to find out the first free i2c ID which can be used for
i2s buses (including i2c buses connected to i2c mux). Do it early in
init and share this variable with other i2c classes for uniq bus
identification.
add from hs:
fix build problem in i2c-uclass.c for omap devices
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Update cadence i2c driver to support livetree
Similar changes were done by:
"net: zynq_gem: convert to use livetree"
(sha1: 26026e695a)
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Updates i2c muxes drivers to support livetree.
Similar changes were done by:
"net: zynq_gem: convert to use livetree"
(sha1: 26026e695a)
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
This is needed to properly calculate i2c bus speed divisors.
Signed-off-by: Tomasz Gorochowik <tgorochowik@antmicro.com>
Signed-off-by: Wojciech Tatarski <wtatarski@antmicro.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Add Xilinx AXI I2C controller driver based on the Linux i2c-xiic driver.
This driver is stripped of all the IRQ handling and uses pure polling,
yet tries to retain most of the structure of the Linux driver to make
backporting of fixes easy.
Note that the IP has a known limitation on 255 bytes read and write,
according to xilinx this is still being worked on [1].
[1] https://forums.xilinx.com/t5/Embedded-Processor-System-Design/AXI-IIC-V2-0-I2C-Master-Reading-multiple-bytes-from-I2C-slave/m-p/854419/highlight/true#M39387
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Heiko Schocher <hs@denx.de>
Reviewed-by: Heiko Schocher <hs@denx.de>
Commit f32a8007ef ("dm: i2c: Make i2c_get_chip_for_busnum() fail if the
chip is not detected") introduced a regression for the NVIDIA Jetson TX2.
For some reason the xfer callback of the tegra i2c driver doesn't support
probing the I2C devices with a 0-length message.
Fixing the regression by providing a dummy implementation of probe_chip()
that does nothing.
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
This allows the driver to be used without OF_CONTROL.
AM335x support DM_SPL but does not use SPL_OF_CONTROL. Enabling DM_I2C in
SPL thus requires that the omap I2C can be passed platdata.
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Move away from SoC specific headers to handle different register layout.
Instead use driver data to get appropriate register layouts like in the
kernel. While at it, perform some mostly cosmetic alignment/cleanup in
the functions being updated.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
i2c_get_chip_for_busnum() really should check the presence of the chip on
the bus. Most of the users of this function assume that this is done.
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Sandbox i2c works using emulation drivers which are currently children of
the i2c device:
rtc_0: rtc@43 {
reg = <0x43>;
compatible = "sandbox-rtc";
emul {
compatible = "sandbox,i2c-rtc";
};
};
In this case the emulation device is attached to i2c bus on address 0x43
and provides the Real-Time-Clock (RTC) functionality.
However this is not ideal, since every device on an I2C bus has a child
device. This is only really the case for sandbox, but we want to avoid
special-case code for sandbox.
A better approach seems to be to add a separate node on the bus, an
'emulation parent'. This can be given a bogus address (such as 0xff) and
hides all the emulators away. Then we can use a phandle to point from the
device to the correct emualtor, and only on sandbox. The code to find an
emulator does not interfere with normal i2c operation.
Add a new UCLASS_I2C_EMUL_PARENT uclass which allows finding an emulator
given a bus, and finding a bus given an emulator. This will be used in a
follow-on patch.
Signed-off-by: Simon Glass <sjg@chromium.org>
