Commit Graph

105 Commits

Author SHA1 Message Date
Joel Stanley fbdb5eac5c fsi: master-hub: Fix sparse warnings
fsi-master-hub.c:128:13: warning: incorrect type in assignment (different base types)
fsi-master-hub.c:128:13:    expected unsigned int [unsigned] [usertype] cmd
fsi-master-hub.c:128:13:    got restricted __be32 [usertype] <noident>
fsi-master-hub.c:208:13: warning: incorrect type in assignment (different base types)
fsi-master-hub.c:208:13:    expected restricted __be32 [addressable] [assigned] [usertype] reg
fsi-master-hub.c:208:13:    got int

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-06-18 14:33:56 +10:00
Joel Stanley 2992513877 fsi: sbefifo: Fix sparse warnings
fsi-sbefifo.c:547:58: warning: incorrect type in argument 2 (different base types)
fsi-sbefifo.c:547:58:    expected restricted __be32 [usertype] *word
fsi-sbefifo.c:547:58:    got unsigned int *<noident>
fsi-sbefifo.c:635:16: warning: incorrect type in assignment (different base types)
fsi-sbefifo.c:635:16:    expected unsigned int [unsigned] <noident>
fsi-sbefifo.c:635:16:    got restricted __be32 [usertype] <noident>
fsi-sbefifo.c:636:16: warning: incorrect type in assignment (different base types)
fsi-sbefifo.c:636:16:    expected unsigned int [unsigned] <noident>
fsi-sbefifo.c:636:16:    got restricted __be32 [usertype] <noident>

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-06-18 14:33:56 +10:00
Benjamin Herrenschmidt a9ef97d098 fsi: sbefifo: Remove unneeded semicolon
Spotted by kbuild-test-bot

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-06-14 14:02:27 +10:00
Benjamin Herrenschmidt 9f4a8a2d7f fsi/sbefifo: Add driver for the SBE FIFO
This driver provides an in-kernel and a user API for accessing
the command FIFO of the SBE (Self Boot Engine) of the POWER9
processor, via the FSI bus.

It provides an in-kernel interface to submit command and receive
responses, along with a helper to locate and analyse the response
status block. It's a simple synchronous submit() type API.

The user interface uses the write/read interface that an earlier
version of this driver already provided, however it has some
specific limitations in order to keep the driver simple and
avoid using up a lot of kernel memory:

 - The user should perform a single write() with the command and
   a single read() to get the response (with a buffer big enough
   to hold the entire response).

 - On a write() the command is simply "stored" into a kernel buffer,
   it is submitted as one operation on the subsequent read(). This
   allows to have the code write directly from the FIFO into the user
   buffer and avoid hogging the SBE between the write() and read()
   syscall as it's critical that the SBE be freed asap to respond
   to the host. An extra write() will simply replace the previously
   written command.

 - A write of a single 4 bytes containing the value 0x52534554
   in big endian will trigger a reset request. No read is necessary,
   the write() call will return when the reset has been acknowledged
   or times out.

 - The command is limited to 4K bytes.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
---
2018-06-12 14:05:39 +10:00
Eddie James 52b7116e88 fsi: scom: Remove PIB reset during probe
The PIB reset causes problems for the running P9 chip. The reset
shouldn't be performed by this driver.

Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:05:34 +10:00
Jeremy Kerr 26d79b272d fsi/master-gpio: Replace bit_bit lock with IRQ disable/enable
We currently use a spinlock (bit_lock) around operations that clock bits
out of the FSI bus, and a mutex to protect against simultaneous access
to the master.

This means that bit_lock isn't needed for mutual exlusion, only to
prevent timing issues when clocking bits out.

To reflect this, this change converts bit_lock to just the
local_irq_save/restore operation.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:05:28 +10:00
Benjamin Herrenschmidt c49e34401a fsi/fsi-master-gpio: More error handling cleanup
Remove calls to the empty and useless fsi_master_gpio_error()
function, and report CRC errors as "FSI_ERR_NO_SLAVE" when
reading an all 1's response.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:05:23 +10:00
Benjamin Herrenschmidt 4e56828a5d fsi/fsi-master-gpio: Implement CRC error recovery
The FSI protocol defines two modes of recovery from CRC errors,
this implements both:

 - If the device returns an ECRC (it detected a CRC error in the
   command), then we simply issue the command again.

 - If the master detects a CRC error in the response, we send
   an E_POLL command which requests a resend of the response
   without actually re-executing the command (which could otherwise
   have unwanted side effects such as dequeuing a FIFO twice).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
---

Note: This was actually tested by removing some of my fixes, thus
causing us to hit occasional CRC errors during high LPC activity.
2018-06-12 14:05:16 +10:00
Jeremy Kerr 0e82e5c1fa fsi/gpio: Use relative-addressing commands
FSI CFAMs support shorter commands that use a relative (or same) address
as the last. This change introduces a last_addr to the master state, and
uses it for subsequent reads/writes, and performs relative addressing
when a subsequent read/write is in range.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:05:10 +10:00
Jeremy Kerr 8193fb4451 fsi/gpio: Include command build in locked section
For implementing relative addressing mode, we'll need to build a command
that is coherent with CFAM state. To do that, include the
build_command_* functions in the locked section of read/write/term.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:05:04 +10:00
Benjamin Herrenschmidt f3ca4834ac fsi/fsi-master-gpio: Delay sampling of FSI data input
Most SoC GPIO implementations, including the Aspeed one, have
synchronizers on the GPIO inputs. This means that the value
read from a GPIO is a couple of clocks old, from whatever clock
source feeds those synchronizers.

In practice, this means that in no-delay mode, we are using a
value that can potentially be a bit too old and too close to
the clock edge establishing the data on the other side of the link.

The voltage converters we use on some systems make this worse
and sensitive to things like voltage fluctuations etc... This is,
we believe, the cause of occasional CRC errors encountered during
heavy activity on the LPC bus.

This is fixed by introducing a dummy GPIO read before the actual
data read. It slows down SBEFIFO by about 15% (less than any delay
primitive) and the end result is so far solid.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:04:59 +10:00
Benjamin Herrenschmidt b632642e4c fsi/fsi-master-gpio: Reduce dpoll clocks
FSI_GPIO_DPOLL_CLOCKS is the number of clocks before sending
a DPOLL command after receiving a BUSY status. It should be
at least tSendDelay (16 clocks).

According to comments in the code, it needs to also be at least
21 clocks due to HW issues.

It's currently 100 clocks which impacts performances negatively
in some cases. Reduces it in half to 50 clocks which seems to
still be solid.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:04:52 +10:00
Benjamin Herrenschmidt 97a4e5c95b fsi/fsi-master-gpio: Reduce turnaround clocks
FSI_GPIO_PRIME_SLAVE_CLOCKS is the number of clocks if the
"idle" phase between the end of a response and the beginning
of the next one. It corresponds to tSendDelay in the FSI
specification.

The default value in the slave is 16 clocks. 100 is way overkill
and significantly reduces the driver performance.

This changes it to 20 (which gives the HW a bit of margin still
just in case).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:04:46 +10:00
Benjamin Herrenschmidt bc1099d2b2 fsi/fsi-master-gpio: Add "no-gpio-delays" option
This adds support for an optional device-tree property that
makes the driver skip all the delays around clocking the
GPIOs and set it in the device-tree of common POWER9 based
OpenPower platforms.

This useful on chips like the AST2500 where the GPIO block is
running at a fairly low clock frequency (25Mhz typically). In
this case, the delays are unnecessary and due to the low
precision of the timers, actually quite harmful in terms of
performance.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:04:41 +10:00
Benjamin Herrenschmidt 5d0d16f135 fsi/fsi-master-gpio: Sample input data on different clock phase
We currently sample the input data right after we toggle the
clock low, then high. The slave establishes the data on the
rising edge, so this is not ideal. We should sample it on
the low phase instead.

This currently works because we have an extra delay, but subsequent
patches will remove it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:04:34 +10:00
Jeremy Kerr e5538139e0 fsi: gpio: Use a mutex to protect transfers
Reduce time spent with interrupts disabled by limiting the critical
sections to bitbanging FSI symbols. We only need to ensure exclusive use
of the bus for an entire transfer, not that the transfer be performed in
atomic context.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:04:26 +10:00
Andrew Jeffery e212ab47bd fsi: gpio: Remove unused 'id' variable
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:04:21 +10:00
Andrew Jeffery 918da95176 fsi: gpio: Trace busy count
An observation from trace output of the existing FSI tracepoints was
that the remote device was sometimes reporting as busy. Add a new
tracepoint reporting the busy count in order to get a better grip on how
often this is the case.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Eddie James <eajames@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
2018-06-12 14:04:13 +10:00
Christopher Bostic f3aa2c6f98 fsi: core: Add check for master property no-scan-on-init
Prior to scanning a master check if the optional property
no-scan-on-init is present.  If it is then avoid scanning.  This is
necessary in cases where a master scan could interfere with another
FSI master on the same bus.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:01 +01:00
Jeremy Kerr e0c24bddf0 fsi: master: Clarify master lifetimes & fix use-after-free in hub master
Once we call fsi_master_unregister, the core will put_device,
potentially freeing the hub master. This change adds a comment
explaining the lifetime of an allocated fsi_master.

We then add a reference from the driver to the hub master, so it stays
around until we've finished ->remove().

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Tested-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:01 +01:00
Christopher Bostic 638bd9ac84 fsi: core: Reduce console output during normal scan
To reduce amount of console output during boot / power up make
all normal path scan related messages debug type.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:01 +01:00
Jeremy Kerr f6a2f8eb73 fsi: Match fsi slaves and engines to available dt nodes
This change populates device tree nodes for scanned FSI slaves and
engines. If the master populates ->of_node of the FSI master device,
we'll look for matching slaves, and under those slaves we'll look for
matching engines.

This means that FSI drivers will have their ->of_node pointer populated
if there's a corresponding DT node, which they can use for further
device discover.

Presence of device tree nodes is optional, and only required for
fsi device drivers that need extra properties, or subordinate devices,
to be enumerated.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:00 +01:00
Eddie James 99f039e97b fsi: Fix one and two byte bus reads/writes
Address checker fixed to allow one and two byte reads/writes.
Address alignments for each size verified.

Signed-off-by: Edward James <eajames@us.ibm.com>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:00 +01:00
Jeremy Kerr b8bd146d38 fsi: master-gpio: Add external mode
This change introduces an 'external mode' for GPIO-based FSI masters,
allowing the clock and data lines to be driven by an external source.
For example, external mode is selected by a user when an external debug
device is attached to the FSI pins.

To do this, we need to set specific states for the trans, mux and enable
GPIOs, and prevent access to clk & data from the FSI core code (by
returning EBUSY).

External mode is controlled by a sysfs attribute, so add the relevant
information to Documentation/ABI/

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:00 +01:00
Jeremy Kerr 29d9b92711 fsi: master-gpio: Add locking during break and link enable
Currently, we perform GPIO accesses in fsi_master_gpio_break and
fsi_master_link_enable, without holding cmd_lock. This change adds the
appropriate locking.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Christopher Bostic <clbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:00 +01:00
Jeremy Kerr 15362d69c4 fsi: Add fsi_master_rescan()
We'll want non-core fsi code to trigger a rescan, so introduce a
non-static fsi_master_rescan() function. Use this for the existing
unscan/scan behaviour too.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Christopher Bostic <clbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:00 +01:00
Vincent Legoll baa8b941cb fsi: Make FSI a menuconfig to ease disabling it all
No need to get into the submenu to disable all FSI-related config entries

Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07 18:41:12 +01:00
Colin Ian King ed50a0890e drivers/fsi: make a couple of functions static
The functions fsi_slave_report_and_clear_errors and fsi_slave_handle_error
are local to the source and do not need to be in global scope, so make
them static.

Cleans up sparse warnings:
symbol 'fsi_slave_report_and_clear_errors' was not declared. Should it
be static?
symbol 'fsi_slave_handle_error' was not declared. Should it be static?

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-04 10:32:42 +02:00
Edward A. James 47a6623b2d drivers/fsi/scom: Remove reset before every putscom
Reset causes problems for operations requiring multiple scoms (e.g. i2c
over scom). Instead, reset scom engine during probe.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28 17:15:16 +02:00
Bhumika Goyal 061c0958de drivers/fsi: add const to bin_attribute structures
Declare bin_attribute structures as const as they are only passed as an
argument to the function device_create_bin_file. This argument is of
type const, so declare the structure as const.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28 17:15:16 +02:00
Arnd Bergmann ceb8a12ff2 drivers/fsi: fix fsi_slave_mode prototype
gcc warns about the return type of this function:

drivers/fsi/fsi-core.c:535:8: error: type qualifiers ignored on function return type [-Werror=ignored-qualifiers]

This removes the 'const' attribute, as suggested by the warning.

Fixes: 2b37c3e285 ("drivers/fsi: Set slave SMODE to init communication")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-17 16:13:54 +02:00
Joel Stanley 496f8931b6 fsi: core: register with postcore_initcall
When testing an i2c driver that is a fsi bus driver, I saw the following
oops:

 kernel BUG at drivers/base/driver.c:153!
 Internal error: Oops - BUG: 0 [#1] ARM

 [<8027cb1c>] (driver_register) from [<80344e88>] (fsi_driver_register+0x2c/0x38)
 [<80344e88>] (fsi_driver_register) from [<805f5ebc>] (fsi_i2c_driver_init+0x1c/0x24)
 [<805f5ebc>] (fsi_i2c_driver_init) from [<805d1f14>] (do_one_initcall+0xb4/0x170)
 [<805d1f14>] (do_one_initcall) from [<805d20f0>] (kernel_init_freeable+0x120/0x1dc)
 [<805d20f0>] (kernel_init_freeable) from [<8043f4a8>] (kernel_init+0x18/0x104)
 [<8043f4a8>] (kernel_init) from [<8000a5e8>] (ret_from_fork+0x14/0x2c)

This is because the fsi bus had not been registered. This fix registers the bus
with postcore_initcall instead, to ensure it is registered earlier on.

When the fsi core is used as a module this should not be a problem as the fsi
driver will depend on the fsi bus type symbol, and will therefore load the core
before the driver.

Fixes: 0508ad1fff ("drivers/fsi: Add empty fsi bus definitions")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-17 16:13:54 +02:00
Christopher Bostic acb7e8f744 drivers/fsi: Add module license to core driver
Add missing MODULE_LICENSE("GPL") to the core FSI driver.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:09 +02:00
Jeremy Kerr 4af889b0ff drivers/fsi: Use asynchronous slave mode
For slaves that are behind a software-clocked master, we want FSI CFAMs
to run asynchronously to the FSI clock, so set up our slaves to be in
async mode.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:09 +02:00
Christopher Bostic 7f9e8f7670 drivers/fsi: Add hub master support
Add an engine driver to expose a "hub" FSI master - which has a set of
control registers in the engine address space, and uses a chunk of the
slave address space for actual FSI communication.

Additional changes from Jeremy Kerr <jk@ozlabs.org>.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:09 +02:00
Christopher Bostic 680ca6dcf5 drivers/fsi: Add SCOM FSI client device driver
Create a simple SCOM engine device driver that reads and writes
its control registers via an FSI bus.

Includes changes from Edward A. James <eajames@us.ibm.com>.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:09 +02:00
Jeremy Kerr 1247cf7ab8 drivers/fsi/gpio: Add tracepoints for GPIO master
Trace low level input/output GPIO operations.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:09 +02:00
Christopher Bostic ac0385d9f6 drivers/fsi: Add GPIO based FSI master
Implement a FSI master using GPIO.  Will generate FSI protocol for
read and write commands to particular addresses.  Sends master command
and waits for and decodes a slave response.

Includes changes from Edward A. James <eajames@us.ibm.com> and Jeremy
Kerr <jk@ozlabs.org>.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:09 +02:00
Jeremy Kerr 1fa847d74a drivers/fsi: Add error handling for slave
This change implements error handling in the FSI core, by cleaining up
and retrying failed operations, using the SISC, TERM and BREAK
facilities.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:09 +02:00
Jeremy Kerr 66433b05a3 drivers/fsi: Add tracepoints for low-level operations
Trace low level read and write FSI bus operations.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Jeremy Kerr da36cadf89 drivers/fsi: expose direct-access slave API
Allow drivers to access the slave address ranges.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Jeremy Kerr 125739cbc1 drivers/fsi: Add sysfs files for FSI master & slave accesses
This change adds a 'raw' file for reads & writes, and a 'term' file for
the TERM command, and a 'break' file for issuing a BREAK.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Christopher Bostic 356d8009a5 drivers/fsi: Add client driver register utilities
Add driver_register and driver_unregister wrappers for FSI.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Christopher Bostic cd0fdb5c07 drivers/fsi: Add master unscan
Allow a master to undo a previous scan.  Should a master scan a bus
twice it will need to ensure it doesn't double register any
previously detected device.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
----
v7 - Unscan when unregistering master
   - Remove leading '__'s from function names
   - Return fail state for sysfs rescan file
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Jeremy Kerr 4efe37f4c4 drivers/fsi: Add device read/write/peek API
This change introduces the fsi device API: simple read, write and peek
accessors for the devices' address spaces.

Includes contributions from Christopher Bostic
<cbostic@linux.vnet.ibm.com> and Edward A. James <eajames@us.ibm.com>.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Jeremy Kerr f7ade2a603 drivers/fsi: scan slaves & register devices
Now that we have fsi_slave devices, scan each for endpoints, and
register them on the fsi bus.

Includes contributions from Christopher Bostic
<cbostic@linux.vnet.ibm.com>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Christopher Bostic 2b37c3e285 drivers/fsi: Set slave SMODE to init communication
Set CFAM to appropriate ID so that the controlling master can manage
link memory ranges.  Add slave engine register definitions.

Includes changes from Jeremy Kerr <jk@ozlabs.org>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Jeremy Kerr 2b545cd8e1 drivers/fsi: Implement slave initialisation
Implement fsi_slave_init: if we can read a chip ID, create fsi_slave
devices and register with the driver core.

Includes changes from Christopher Bostic <cbostic@linux.vnet.ibm.com>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Christopher Bostic 2609528211 drivers/fsi: Set up links for slave communication
Enable each link and send a break command, and try to detect a slave by
reading from the SMODE register.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Jeremy Kerr 014c2abc53 drivers/fsi: Add slave & master read/write APIs
Introduce functions to perform reads/writes on the slave address space;
these simply pass the request on the slave's master with the correct
link and slave ID.

We implement these on top of similar helpers for the master.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:07 +02:00
Jeremy Kerr 414c102631 drivers/fsi: Add empty master scan
When a new fsi master is added, we will need to scan its links, and
slaves attached to those links. This change introduces a little shell to
iterate the links, which we will populate with the actual slave scan in
a later change.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:07 +02:00
Jeremy Kerr faf0b116de drivers/fsi: Add slave definition
Add the initial fsi slave device, which is private to the core code.
This will be a child of the master, and parent to endpoint devices.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:07 +02:00
Jeremy Kerr 09aecfab93 drivers/fsi: Add fsi master definition
Add a `struct fsi_master` to represent a FSI master controller.

FSI master drivers register one of these structs to provide
device-specific of the standard operations: read/write/term/break and
link control.

Includes changes from Edward A. James <eajames@us.ibm.com> & Jeremy Kerr
<jk@ozlabs.org>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:07 +02:00
Jeremy Kerr dd37eed7db drivers/fsi: add driver to device matches
Driver bind to devices based on the engine types & (optional) versions.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:19:48 +01:00
Jeremy Kerr 0508ad1fff drivers/fsi: Add empty fsi bus definitions
This change adds the initial (empty) fsi bus definition, and introduces
drivers/fsi/.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:19:48 +01:00