The ASPEED KCS devices don't provide a BMC-side interrupt for the host
reading the output data register (ODR). The act of the host reading ODR
clears the output buffer full (OBF) flag in the status register (STR),
informing the BMC it can transmit a subsequent byte.
On the BMC side the KCS client must enable the OBE event *and* perform a
subsequent read of STR anyway to avoid races - the polling provides a
window for the host to read ODR if data was freshly written while
minimising BMC-side latency.
Fixes: 28651e6c42 ("ipmi: kcs_bmc: Allow clients to control KCS IRQ state")
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-Id: <20220812144741.240315-1-andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Remove AST_usrGuide_KCS.pdf as it is no longer maintained.
Add more descriptions as the driver now supports the I/O
address configurations for both the KCS Data and Cmd/Status
interface registers.
Signed-off-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>
Message-Id: <20220920020333.601-1-chiawei_wang@aspeedtech.com>
[I don't like removing documentation, but the document in question
was a personal note by an employee and nothing official and not
necessarily guaranteed to be accurate in the future. So go
ahead and remove it.]
Signed-off-by: Corey Minyard <cminyard@mvista.com>
It's been a few releases since we depreciated the "v1" bindings. Remove
support from the driver as all known device trees have been updated to
use the new bindings.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Message-Id: <20220228062840.449215-1-joel@jms.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
The AST2600 is already described in the bindings, but the driver never
gained a compatible string.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Message-Id: <20220221070351.121905-1-joel@jms.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
The comparisons of the unsigned int hw_type to less than zero always
false because it is unsigned. Fix this by using an int for the
assignment and less than zero check.
Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 9d2df9a0ad80 ("ipmi: kcs_bmc_aspeed: Implement KCS SerIRQ configuration")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Message-Id: <20210616162913.15259-1-colin.king@canonical.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Some Aspeed KCS devices can derive the status register address from the
address of the data register. As such, the address of the status
register can be implicit in the configuration if desired. On the other
hand, sometimes address schemes might be requested that are incompatible
with the default addressing scheme. Allow these requests where possible
if the devicetree specifies the status register address.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>
Message-Id: <20210608104757.582199-17-andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Input Buffer Full Interrupt Enable (IBFIE) is typoed as IBFIF for some
registers in the datasheet. Fix the driver to use the sensible acronym.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
Message-Id: <20210608104757.582199-16-andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Apply the SerIRQ ID and level/sense behaviours from the devicetree if
provided.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Message-Id: <20210608104757.582199-15-andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
This way devices don't get delivered IRQs when no-one is interested.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Message-Id: <20210608104757.582199-11-andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Add a mechanism for controlling whether the client associated with a
KCS device will receive Input Buffer Full (IBF) and Output Buffer Empty
(OBE) events. This enables an abstract implementation of poll() for KCS
devices.
A wart in the implementation is that the ASPEED KCS devices don't
support an OBE interrupt for the BMC. Instead we pretend it has one by
polling the status register waiting for the Output Buffer Full (OBF) bit
to clear, and generating an event when OBE is observed.
Cc: CS20 KWLiu <KWLIU@nuvoton.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
Message-Id: <20210608104757.582199-10-andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Move all client-private data out of `struct kcs_bmc` into the KCS client
implementation.
With this change the KCS BMC core code now only concerns itself with
abstract `struct kcs_bmc` and `struct kcs_bmc_client` types, achieving
expected separation of concerns. Further, the change clears the path for
implementation of alternative userspace interfaces.
The chardev data-structures are rearranged in the same manner applied to
the KCS device driver data-structures in an earlier patch - `struct
kcs_bmc_client` is embedded in the client's private data and we exploit
container_of() to translate as required.
Finally, now that it is free of client data, `struct kcs_bmc` is renamed
to `struct kcs_bmc_device` to contrast `struct kcs_bmc_client`.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
Message-Id: <20210608104757.582199-8-andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Strengthen the distinction between code that abstracts the
implementation of the KCS behaviours (device drivers) and code that
exploits KCS behaviours (clients). Neither needs to know about the APIs
required by the other, so provide separate headers.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Message-Id: <20210608104757.582199-7-andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Make the KCS device drivers responsible for allocating their own memory.
Until now the private data for the device driver was allocated internal
to the private data for the chardev interface. This coupling required
the slightly awkward API of passing through the struct size for the
driver private data to the chardev constructor, and then retrieving a
pointer to the driver private data from the allocated chardev memory.
In addition to being awkward, the arrangement prevents the
implementation of alternative userspace interfaces as the device driver
private data is not independent.
Peel a layer off the onion and turn the data-structures inside out by
exploiting container_of() and embedding `struct kcs_device` in the
driver private data.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
Message-Id: <20210608104757.582199-6-andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Enable more efficient implementation of read-modify-write sequences.
Both device drivers for the KCS BMC stack use regmaps. The new callback
allows us to exploit regmap_update_bits().
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
Message-Id: <20210608104757.582199-3-andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Unpack and remove the aspeed_kcs_probe_of_v[12]() functions to aid
rearranging how the private device-driver memory is allocated.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Message-Id: <20210608104757.582199-2-andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Add check against LPC device v2 compatible string to
ensure that the fixed device tree layout is adopted.
The LPC register offsets are also fixed accordingly.
Signed-off-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Haiyue Wang <haiyue.wang@linux.intel.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210319062752.145730-3-andrew@aj.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>
This needs to return the newly allocated struct but instead it returns
zero which leads to an immediate Oops in the caller.
Fixes: 09f5f68070 ("ipmi: kcs: aspeed: Implement v2 bindings")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Message-Id: <20200407122149.GA100026@mwanda>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
The v2 bindings allow us to extract the resources from the devicetree.
The table in the driver is retained to derive the channel index, which
removes the need for kcs_chan property from the v1 bindings. The v2
bindings allow us to reduce the number of warnings generated by the
existing devicetree nodes.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Haiyue Wang <haiyue.wang@linux.intel.com>
Message-Id: <01ef3787e9ddaa9d87cfd55a2ac793053b5a69de.1576462051.git-series.andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
The interrupts were configured after the channel was enabled. Configure
them beforehand so they will work.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Haiyue Wang <haiyue.wang@linux.intel.com>
Message-Id: <c0aba2c9dfe2d0525e9cefd37995983ead0ec242.1576462051.git-series.andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Many for coding-style fixes, and update the poll API with the new
type '__poll_t', this is new commit from linux-4.16-rc1.
Signed-off-by: Haiyue Wang <haiyue.wang@linux.intel.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
The KCS (Keyboard Controller Style) interface is used to perform in-band
IPMI communication between a server host and its BMC (BaseBoard Management
Controllers).
This driver exposes the KCS interface on ASpeed SOCs (AST2400 and AST2500)
as a character device. Such SOCs are commonly used as BMCs and this driver
implements the BMC side of the KCS interface.
Signed-off-by: Haiyue Wang <haiyue.wang@linux.intel.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Andrew Jeffery