Commit Graph

40 Commits

Author SHA1 Message Date
Klaus Jensen
791cb95f23 hw/i2c: only schedule pending master when bus is idle
It is not given that the current master will release the bus after a
transfer ends. Only schedule a pending master if the bus is idle.

Fixes: 37fa5ca426 ("hw/i2c: support multiple masters")
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Message-Id: <20221116084312.35808-2-its@irrelevant.dk>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2023-03-02 13:57:50 +01:00
Peter Delevoryas
3648d31fa8 hw/i2c/aspeed: Fix old reg slave receive
I think when Klaus ported his slave mode changes from the original patch
series to the rewritten I2C module, he changed the behavior of the first
byte that is received by the slave device.

What's supposed to happen is that the AspeedI2CBus's slave device's
i2c_event callback should run, and if the event is "send_async", then it
should populate the byte buffer with the 8-bit I2C address that is being
sent to. Since we only support "send_async", the lowest bit should
always be 0 (indicating that the master is requesting to send data).

This is the code Klaus had previously, for reference. [1]

    switch (event) {
    case I2C_START_SEND:
        bus->buf = bus->dev_addr << 1;

        bus->buf &= I2CD_BYTE_BUF_RX_MASK;
        bus->buf <<= I2CD_BYTE_BUF_RX_SHIFT;

        bus->intr_status |= (I2CD_INTR_SLAVE_ADDR_RX_MATCH | I2CD_INTR_RX_DONE);
        aspeed_i2c_set_state(bus, I2CD_STXD);

        break;

[1]: https://lore.kernel.org/qemu-devel/20220331165737.1073520-4-its@irrelevant.dk/

Fixes: a8d48f59cd ("hw/i2c/aspeed: add slave device in old register mode")
Signed-off-by: Peter Delevoryas <peter@pjd.dev>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Message-Id: <20220820225712.713209-2-peter@pjd.dev>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-10-24 11:20:15 +02:00
Peter Delevoryas
1c5d909f88 hw/i2c/aspeed: Add new-registers DMA slave mode RX support
This commit adds support for DMA RX in slave mode while using the new
register set in the AST2600 and AST1030. This patch also pretty much
assumes packet mode is enabled, I'm not sure if this will work in DMA
step mode.

This is particularly useful for testing IPMB exchanges between Zephyr
and external devices, which requires multi-master I2C support and DMA in
the new register mode, because the Zephyr drivers from Aspeed use DMA in
the new mode by default. The Zephyr drivers are also using packet mode.

The typical sequence of events for receiving data in DMA slave + packet
mode is that the Zephyr firmware will configure the slave address
register with an address to receive on and configure the bus's function
control register to enable master mode and slave mode simultaneously at
startup, before any transfers are initiated.

RX DMA is enabled in the slave mode command register, and the slave RX
DMA buffer address and slave RX DMA buffer length are set. TX DMA is not
covered in this patch.

When the Aspeed I2C controller receives data from some other I2C master,
it will reset the I2CS_DMA_LEN RX_LEN value to zero, then buffer
incoming data in the RX DMA buffer while incrementing the I2CC_DMA_ADDR
address counter and decrementing the I2CC_DMA_LEN counter. It will also
update the I2CS_DMA_LEN RX_LEN value along the way.

Once all the data has been received, the bus controller will raise an
interrupt indicating a packet command was completed, the slave address
matched, a normal stop condition was seen, and the transfer was an RX
operation.

If the master sent a NACK instead of a normal stop condition, or the
transfer timed out, then a slightly different set of interrupt status
values would be set. Those conditions are not handled in this commit.

The Zephyr firmware then collects data from the RX DMA buffer and clears
the status register by writing the PKT_MODE_EN bit to the status
register. In packet mode, clearing the packet mode interrupt enable bit
also clears most of the other interrupt bits automatically (except for a
few bits above it).

Note: if the master transmit or receive functions were in use
simultaneously with the slave mode receive functionality, then the
master mode functions may have raised the interrupt line for the bus
before the DMA slave transfer is complete. It's important to have the
slave's interrupt status register clear throughout the receive
operation, and if the slave attempts to raise the interrupt before the
master interrupt status is cleared, then it needs to re-raise the
interrupt once the master interrupt status is cleared. (And vice-versa).
That's why in this commit, when the master interrupt status is cleared
and the interrupt line is lowered, we call the slave interrupt _raise_
function, to see if the interrupt was pending. (And again, vice-versa).

Signed-off-by: Peter Delevoryas <pdel@fb.com>
Message-Id: <20220630045133.32251-8-me@pjd.dev>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-30 09:21:14 +02:00
Klaus Jensen
a8d48f59cd hw/i2c/aspeed: add slave device in old register mode
Add slave mode functionality for the Aspeed I2C controller in old
register mode. This is implemented by realizing an I2C slave device
owned by the I2C controller and attached to its own bus.

The I2C slave device only implements asynchronous sends on the bus, so
slaves not supporting that will not be able to communicate with it.

Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
[ clg: checkpatch fixes ]
Message-Id: <20220601210831.67259-6-its@irrelevant.dk>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20220630045133.32251-7-me@pjd.dev>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-30 09:21:14 +02:00
Peter Delevoryas
0c0f1bee6a hw/i2c/aspeed: Fix MASTER_EN missing error message
aspeed_i2c_bus_is_master is checking if master mode is enabled in the I2C
bus controller's function-control register, not that slave mode is enabled
or something.  The error here is that the guest is trying to trigger an I2C
master mode command while master mode is not enabled.

Fixes: ba2cccd64e ("aspeed: i2c: Add new mode support")
Signed-off-by: Peter Delevoryas <pdel@fb.com>
Message-Id: <20220630045133.32251-4-me@pjd.dev>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-30 09:21:14 +02:00
Peter Delevoryas
b582b7a191 hw/i2c/aspeed: Fix DMA len write-enable bit handling
I noticed i2c rx transfers were getting shortened to "1" on Zephyr. It
seems to be because the Zephyr i2c driver sets the RX DMA len with the
RX field write-enable bit set (bit 31) to avoid a read-modify-write. [1]

/* 0x1C : I2CM Master DMA Transfer Length Register   */

I think we should be checking the write-enable bits on the incoming
value, not checking the register array. I'm not sure we're even writing
the write-enable bits to the register array, actually.

[1] db3dbcc9c5/drivers/i2c/i2c_aspeed.c (L145-L148)

Fixes: ba2cccd64e ("aspeed: i2c: Add new mode support")
Signed-off-by: Peter Delevoryas <pdel@fb.com>
Message-Id: <20220630045133.32251-3-me@pjd.dev>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-30 09:21:13 +02:00
Peter Delevoryas
ceb3ff0e80 hw/i2c/aspeed: Fix R_I2CD_FUN_CTRL reference
Very minor, doesn't effect functionality, but this is supposed to be
R_I2CC_FUN_CTRL (new-mode, not old-mode).

Fixes: ba2cccd64e ("aspeed: i2c: Add new mode support")
Signed-off-by: Peter Delevoryas <pdel@fb.com>
Message-Id: <20220630045133.32251-2-me@pjd.dev>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-30 09:21:13 +02:00
Cédric Le Goater
6743af9b10 aspeed/i2c: Change trace event for NORMAL_STOP states
Using a 'stop' string seems more appropriate than 'normal'.

Reviewed-by: Peter Delevoryas <pdel@fb.com>
Message-Id: <20220628154740.1117349-3-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-30 09:21:13 +02:00
Cédric Le Goater
33e30f11c7 aspeed/i2c: Enable SLAVE_ADDR_RX_MATCH always
There is no 'slave match interrupt' enable bit in the Interrupt
Control Register. Consider it is always enabled and extend the mask
value 'bus->regs[intr_ctrl_reg]' with the SLAVE_ADDR_RX_MATCH bit when
the interrupt is raised.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-22 09:49:34 +02:00
Klaus Jensen
d72a712ce0 hw/i2c/aspeed: add DEV_ADDR in old register mode
Add support for writing and reading the device address register in old
register mode.

On the AST2400 (only 1 slave address)

  * no upper bits

On the AST2500 (2 possible slave addresses),

  * bit[31] : Slave Address match indicator
  * bit[30] : Slave Address Receiving pending

On the AST2600 (3 possible slave addresses),

  * bit[31-30] : Slave Address match indicator
  * bit[29] : Slave Address Receiving pending

The model could be more precise to take into account all fields but
since the Linux driver is masking the register value being set, it
should be fine. See commit 3fb2e2aeafb2 ("i2c: aspeed: disable
additional device addresses on ast2[56]xx") from Zeiv. This can be
addressed later.

Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
[ clg: add details to commit log ]
Message-Id: <20220601210831.67259-3-its@irrelevant.dk>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-22 09:49:34 +02:00
Klaus Jensen
b03ec4ff06 hw/i2c/aspeed: rework raise interrupt trace event
Build a single string instead of having several parameters on the trace
event.

Suggested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
[ clg: simplified trace buffer creation ]
Message-Id: <20220601210831.67259-2-its@irrelevant.dk>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-22 09:49:34 +02:00
Cédric Le Goater
b35802ce31 aspeed/i2c: Add ast1030 controller models
Based on :

  https://lore.kernel.org/qemu-devel/20220324100439.478317-2-troy_lee@aspeedtech.com/

Cc: Troy Lee <troy_lee@aspeedtech.com>
Cc: Jamin Lin <jamin_lin@aspeedtech.com>
Cc: Steven Lee <steven_lee@aspeedtech.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-22 09:49:34 +02:00
Joe Komlodi
e532cd0485 aspeed: i2c: Move regs and helpers to header file
Moves register definitions and short commonly used inlined functiosn to
the header file to help tidy up the implementation file.

Signed-off-by: Joe Komlodi <komlodi@google.com>
Change-Id: I34dff7485b6bbe3c9482715ccd94dbd65dc5f324
Message-Id: <20220331043248.2237838-8-komlodi@google.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-22 09:49:34 +02:00
Joe Komlodi
0efec47b5f aspeed: i2c: Add PKT_DONE IRQ to trace
Signed-off-by: Joe Komlodi <komlodi@google.com>
Change-Id: I566eb09f4b9016e24570572f367627f6594039f5
Message-Id: <20220331043248.2237838-7-komlodi@google.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-22 09:49:34 +02:00
Joe Komlodi
ba2cccd64e aspeed: i2c: Add new mode support
On AST2600, I2C has a secondary mode, called "new mode", which changes
the layout of registers, adds some minor behavior changes, and
introduces a new way to transfer data called "packet mode".

Most of the bit positions of the fields are the same between old and new
mode, so we use SHARED_FIELD_XX macros to reuse most of the code between
the different modes.

For packet mode, most of the command behavior is the same compared to
other modes, but there are some minor changes to how interrupts are
handled compared to other modes.

Signed-off-by: Joe Komlodi <komlodi@google.com>
Change-Id: I072f8301964f623afc74af1fe50c12e5caef199e
Message-Id: <20220331043248.2237838-6-komlodi@google.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-22 09:49:34 +02:00
Joe Komlodi
2260fc6ff3 aspeed: i2c: Use reg array instead of individual vars
Using a register array will allow us to represent old-mode and new-mode
I2C registers by using the same underlying register array, instead of
adding an entire new set of variables to represent new mode.

As part of this, we also do additional cleanup to use ARRAY_FIELD_
macros instead of FIELD_ macros on registers.

Signed-off-by: Joe Komlodi <komlodi@google.com>
Change-Id: Ib94996b17c361b8490c042b43c99d8abc69332e3
[ clg: use of memset in aspeed_i2c_bus_reset() ]
Message-Id: <20220331043248.2237838-5-komlodi@google.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-22 09:49:34 +02:00
Joe Komlodi
3be3d6ccf2 aspeed: i2c: Migrate to registerfields API
This cleans up some of the field accessing, setting, and clearing
bitwise operations, and wraps them in macros instead.

Signed-off-by: Joe Komlodi <komlodi@google.com>
Change-Id: I33018d6325fa04376e7c29dc4a49ab389a8e333a
Message-Id: <20220331043248.2237838-4-komlodi@google.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2022-06-22 09:49:34 +02:00
Cédric Le Goater
602610383f aspeed/i2c: QOMify AspeedI2CBus
Introduce an AspeedI2CBus SysBusDevice model and attach the associated
memory region and IRQ to the newly instantiated objects.

Before this change, the I2C bus IRQs were all attached to the
SysBusDevice model of the I2C controller. Adapt the AST2600 SoC
realize routine to take into account this change.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-10-12 08:20:08 +02:00
Cédric Le Goater
3f7a53b224 aspeed/i2c: Rename DMA address space
It improves 'info mtree' output.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210407171637.777743-5-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-05-01 10:03:51 +02:00
Cédric Le Goater
7492515909 aspeed/i2c: Fix DMA address mask
The RAM memory region is now used for DMAs accesses instead of the
memory address space region. Mask off the top bits of the DMA address
to reflect this change.

Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20210407171637.777743-4-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-05-01 10:03:51 +02:00
Philippe Mathieu-Daudé
7a204cbdc2 hw/i2c/aspeed_i2c: Simplify aspeed_i2c_get_bus()
All the callers of aspeed_i2c_get_bus() have a AspeedI2CState and
cast it to a DeviceState with DEVICE(), then aspeed_i2c_get_bus()
cast the DeviceState to an AspeedI2CState with ASPEED_I2C()...

Simplify aspeed_i2c_get_bus() callers by using AspeedI2CState
argument.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200705224154.16917-2-f4bug@amsat.org>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
2020-07-16 12:30:54 -05:00
Miroslav Rezanina
f821bac4af aspeed/i2c: Prevent uninitialized warning
Compiler reports uninitialized warning for cmd_flags variable.

Adding NULL initialization to prevent this warning.

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <07957dcab31f65de3dd30efa91e6b9152ac79879.1579598240.git.mrezanin@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-02-06 11:13:24 +01:00
Marc-André Lureau
4f67d30b5e qdev: set properties with device_class_set_props()
The following patch will need to handle properties registration during
class_init time. Let's use a device_class_set_props() setter.

spatch --macro-file scripts/cocci-macro-file.h  --sp-file
./scripts/coccinelle/qdev-set-props.cocci --keep-comments --in-place
--dir .

@@
typedef DeviceClass;
DeviceClass *d;
expression val;
@@
- d->props = val
+ device_class_set_props(d, val)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-20-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:15 +01:00
Cédric Le Goater
66cc84a1a3 aspeed/i2c: Add trace events
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20191119141211.25716-6-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-12-16 10:46:34 +00:00
Cédric Le Goater
545d6bef70 aspeed/i2c: Add support for DMA transfers
The I2C controller of the Aspeed AST2500 and AST2600 SoCs supports DMA
transfers to and from DRAM.

A pair of registers defines the buffer address and the length of the
DMA transfer. The address should be aligned on 4 bytes and the maximum
length should not exceed 4K. The receive or transmit DMA transfer can
then be initiated with specific bits in the Command/Status register of
the controller.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20191119141211.25716-5-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-12-16 10:46:34 +00:00
Cédric Le Goater
aab90b1cac aspeed/i2c: Check SRAM enablement on AST2500
The SRAM must be enabled before using the Buffer Pool mode or the DMA
mode. This is not required on other SoCs.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20191119141211.25716-3-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-12-16 10:46:34 +00:00
Cédric Le Goater
6054fc73e8 aspeed/i2c: Add support for pool buffer transfers
The Aspeed I2C controller can operate in different transfer modes :

  - Byte Buffer mode, using a dedicated register to transfer a
    byte. This is what the model supports today.

  - Pool Buffer mode, using an internal SRAM to transfer multiple
    bytes in the same command sequence.

Each SoC has different SRAM characteristics. On the AST2400, 2048
bytes of SRAM are available at offset 0x800 of the controller AHB
window. The pool buffer can be configured from 1 to 256 bytes per bus.

On the AST2500, the SRAM is at offset 0x200 and the pool buffer is of
16 bytes per bus.

On the AST2600, the SRAM is at offset 0xC00 and the pool buffer is of
32 bytes per bus. It can be splitted in two for TX and RX but the
current model does not add support for it as it it unused by known
drivers.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20191119141211.25716-2-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-12-16 10:46:34 +00:00
Cédric Le Goater
51dd49236b aspeed/i2c: Add AST2600 support
The I2C controller of the AST2400 and AST2500 SoCs have one IRQ shared
by all I2C busses. The AST2600 SoC I2C controller has one IRQ per bus
and 16 busses.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-17-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-15 18:09:04 +01:00
Cédric Le Goater
f7da1aa8fe aspeed/i2c: Introduce an object class per SoC
It prepares ground for register differences between SoCs.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-16-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-15 18:09:04 +01:00
Markus Armbruster
d645427057 Include migration/vmstate.h less
In my "build everything" tree, changing migration/vmstate.h triggers a
recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).

hw/hw.h supposedly includes it for convenience.  Several other headers
include it just to get VMStateDescription.  The previous commit made
that unnecessary.

Include migration/vmstate.h only where it's still needed.  Touching it
now recompiles only some 1600 objects.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-16-armbru@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:52 +02:00
Markus Armbruster
64552b6be4 Include hw/irq.h a lot less
In my "build everything" tree, changing hw/irq.h triggers a recompile
of some 5400 out of 6600 objects (not counting tests and objects that
don't depend on qemu/osdep.h).

hw/hw.h supposedly includes it for convenience.  Several other headers
include it just to get qemu_irq and.or qemu_irq_handler.

Move the qemu_irq and qemu_irq_handler typedefs from hw/irq.h to
qemu/typedefs.h, and then include hw/irq.h only where it's still
needed.  Touching it now recompiles only some 500 objects.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-13-armbru@redhat.com>
2019-08-16 13:31:52 +02:00
Markus Armbruster
0b8fa32f55 Include qemu/module.h where needed, drop it from qemu-common.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-4-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
hw/usb/dev-hub.c hw/misc/exynos4210_rng.c hw/misc/bcm2835_rng.c
hw/misc/aspeed_scu.c hw/display/virtio-vga.c hw/arm/stm32f205_soc.c;
ui/cocoa.m fixed up]
2019-06-12 13:18:33 +02:00
Corey Minyard
bc15cde0c4 i2c: Don't check return value from i2c_recv()
i2c_recv() cannot fail, so there is no need to check the return
value.  It also returns unt8_t, so comparing with < 0 is not
meaningful.

Fix up various I2C controllers to remove the unneeded code.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
2019-02-27 21:06:08 -06:00
Guenter Roeck
bb626e5b43 aspeed/i2c: Fix receive done interrupt handling
The AST2500 datasheet says:

I2CD10 Interrupt Status Register
       bit 2 Receive Done Interrupt status
             S/W needs to clear this status bit to allow next data receiving

The Rx interrupt done interrupt status bit needs to be cleared
explicitly before the next byte can be received, and must therefore
not be auto-cleared. Also, receiving the next byte must be delayed
until the bit has been cleared.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20180914063506.20815-4-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-09-25 14:14:07 +01:00
Guenter Roeck
7bd9c60d4e aspeed/i2c: Handle receive command in separate function
Receive command handling may have to be deferred if a previous receive
done interrupt was not yet acknowledged. Move receive command handling
into a separate function to prepare for the necessary changes.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20180914063506.20815-3-clg@kaod.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-09-25 14:14:07 +01:00
Cédric Le Goater
5540cb97f7 aspeed/i2c: interrupts should be cleared by software only
aspeed i2c interrupts should be cleared by software only, and the bus
interrupt should be lowered when all interrupts have been cleared.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20180914063506.20815-2-clg@kaod.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: drop TODO comment describing an issue which is
 fixed later in the patch series, and clean up commit message]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-09-25 14:14:07 +01:00
Cédric Le Goater
4960f084cf aspeed/i2c: introduce a state machine
The Aspeed I2C controller maintains a state machine in the command
register, which is mostly used for debug.

Let's start adding a few states to handle abnormal STOP
commands. Today, the model uses the busy status of the bus as a
condition to do so but it is not precise enough.

Also remove the ABNORMAL bit for failing TX commands. This is
incorrect with respect to the specs.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 1494827476-1487-4-git-send-email-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-06-02 11:51:49 +01:00
Cédric Le Goater
d0efdc1686 aspeed/i2c: handle LAST command under the RX command
Today, the LAST command is handled with the STOP command but this is
incorrect. Also nack the I2C bus when a LAST is issued.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 1494827476-1487-3-git-send-email-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-06-02 11:51:49 +01:00
Cédric Le Goater
ddabca757a aspeed/i2c: improve command handling
Multiple I2C commands can be fired simultaneously and the controller
execute the commands following these priorities:

  (1) Master Start Command
  (2) Master Transmit Command
  (3) Slave Transmit Command or Master Receive Command
  (4) Master Stop Command

The current code is incorrect with respect to the above sequence and
needs to be reworked to handle each individual command.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 1494827476-1487-2-git-send-email-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-06-02 11:51:49 +01:00
Cédric Le Goater
1602001195 i2c: add aspeed i2c controller
The Aspeed AST2400 integrates a set of 14 I2C/SMBus bus controllers
directly connected to the APB bus. They can be programmed as master or
slave but the propopsed model only supports the master mode.

On the TODO list, we also have :

 - improve and harden the state machine.
 - bus recovery support (used by the Linux driver).
 - transfer mode state machine bits. this is not strictly necessary as
   it is mostly used for debug. The bus busy bit is deducted from the
   I2C core engine of qemu.
 - support of the pool buffer: 2048 bytes of internal SRAM (not used
   by the Linux driver).

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Message-id: 1464704307-25178-1-git-send-email-clg@kaod.org
[PMM: removed unused functions aspeed_i2c_bus_get_state() and
 aspeed_i2c_bus_set_state()]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-06-06 16:59:29 +01:00