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>
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>
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>
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>
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>
Back in 2016, we discussed[1] rules for headers, and these were
generally liked:
1. Have a carefully curated header that's included everywhere first. We
got that already thanks to Peter: osdep.h.
2. Headers should normally include everything they need beyond osdep.h.
If exceptions are needed for some reason, they must be documented in
the header. If all that's needed from a header is typedefs, put
those into qemu/typedefs.h instead of including the header.
3. Cyclic inclusion is forbidden.
This patch gets include/ closer to obeying 2.
It's actually extracted from my "[RFC] Baby steps towards saner
headers" series[2], which demonstrates a possible path towards
checking 2 automatically. It passes the RFC test there.
[1] Message-ID: <87h9g8j57d.fsf@blackfin.pond.sub.org>
https://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg03345.html
[2] Message-Id: <20190711122827.18970-1-armbru@redhat.com>
https://lists.nongnu.org/archive/html/qemu-devel/2019-07/msg02715.html
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-2-armbru@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
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>