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* fsi: Add cfam char devicesBenjamin Herrenschmidt2018-07-271-51/+213
| | | | | | | | | | | | This aims to deprecate the "raw" sysfs file used for directly accessing the CFAM and instead use a char device like the other sub drivers. Since it reworks the slave creation code and adds a cfam device type, we also use the opportunity to convert the attributes to attribute groups and add a couple more. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: scom: Convert to use the new chardevBenjamin Herrenschmidt2018-07-271-50/+80
| | | | | | | This converts FSI scom to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: sbefifo: Convert to use the new chardevBenjamin Herrenschmidt2018-07-271-29/+55
| | | | | | | | | | | This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: Add new central chardev supportBenjamin Herrenschmidt2018-07-272-2/+108
| | | | | | | | | | | | | | | | | | | | | | | | | | | The various FSI devices (sbefifo, occ, scom, more to come) currently use misc devices. This is problematic as the minor device space for misc is limited and there can be a lot of them. Also it limits our ability to move them to a dedicated /dev/fsi directory or to be smart about device naming and numbering. It also means we have IDAs on every single of these drivers This creates a common fsi "device_type" for the optional /dev/fsi grouping and a dev_t allocator for all FSI devices. "Legacy" devices get to use a backward compatible numbering scheme (as long as chip id <16 and there's only one copy of a given unit type per chip). A single major number and a single IDA are shared for all FSI devices. This doesn't convert the FSI device drivers to use the new scheme yet, they will be converted individually. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: master-ast-cf: Rename dump_trace() to avoid name collisionBenjamin Herrenschmidt2018-07-261-5/+5
| | | | | | | s390 defines a global dump_trace() symbol. Rename ours to dump_ucode_trace() to avoid a collision in build tests. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: master-ast-cf: Fix memory leakGustavo A. R. Silva2018-07-261-2/+4
| | | | | | | | | | In case memory resources for *fw* were allocated, release them before return. Addresses-Coverity-ID: 1472044 ("Resource leak") Fixes: 6a794a27daca ("fsi: master-ast-cf: Add new FSI master using Aspeed ColdFire") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: master-ast-cf: Mask unused bits in RTAG/RCRCBenjamin Herrenschmidt2018-07-251-2/+2
| | | | | | | | | | Then reading the RTAG/RCRC "registers" from the coprocessor after a command is complete, mask out the top bits, only keep the relevant bits. Microcode v5 will leave garbage in those top bits as a result of a performance optimization. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> ---
* fsi: master-ast-cf: Fix build warnings on 64-bit platformsBenjamin Herrenschmidt2018-07-241-2/+2
| | | | | | | A couple of places forgot the 'z' qualifier for dev_dbg when printing a size_t Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: Add support for device-tree provided chip IDsBenjamin Herrenschmidt2018-07-231-0/+24
| | | | | | | They get retrieved from the device-tree and exposed as an attribute in sysfs Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: sbefifo: Fix inconsistent use of ffdc mutexBenjamin Herrenschmidt2018-07-231-4/+9
| | | | | | | Some of the exit path missed the unlock. Move the mutex to an outer function to avoid the problem completely Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: master-ast-cf: Add new FSI master using Aspeed ColdFireBenjamin Herrenschmidt2018-07-234-0/+1605
| | | | | | | | | | | | | | The Aspeed AST2x00 can contain a ColdFire v1 coprocessor which is currently unused on OpenPower systems. This adds an alternative to the fsi-master-gpio driver that uses that coprocessor instead of bit banging from the ARM core itself. The end result is about 4 times faster. The firmware for the coprocessor and its source code can be found at https://github.com/ozbenh/cf-fsi and is system specific. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: Move various master definitions to a common headerBenjamin Herrenschmidt2018-07-122-29/+33
| | | | | | | | | | This moves the definitions for various protocol details (message & response codes, delays etc...) out of fsi-master-gpio.c to fsi-master.h in order to share them with other master implementations. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Joel Stanley <joel@jms.id.au>
* fsi: master-gpio: Add missing release functionBenjamin Herrenschmidt2018-07-121-18/+35
| | | | | | | | | | | | | The embedded struct device needs a release function to be able to successfully remove the driver. We remove the devm_gpiod_put() as they are unnecessary (the resources will be released automatically) and because fsi_master_unregister() will cause the master structure to be freed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Joel Stanley <joel@jms.id.au>
* fsi: Don't use device_unregister() in fsi_master_register()Benjamin Herrenschmidt2018-07-121-5/+2
| | | | | | | | | | | | | | In the error path of fsi_master_register(), we currently use device_unregister(). This will cause the last reference to the structure to be dropped, thus freeing the enclosing structure, which isn't what the callers want. Use device_del() instead so that we return to the caller with a refcount of 1. The caller can then assume that it must use put_device() after a call to fsi_master_register() regardless of whether the latter suceeded or failed. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: master-gpio: Remove "GPIO" prefix on some definitionsBenjamin Herrenschmidt2018-07-121-34/+36
| | | | | | | | | | | | | Some definitions are generic to the FSI protocol or any give master implementation. Rename them to remove the "GPIO" prefix in preparation for moving them to a common header. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Joel Stanley <joel@jms.id.au> # Conflicts: # drivers/fsi/fsi-master-gpio.c
* fsi: master-gpio: Remove unused definitionsBenjamin Herrenschmidt2018-07-121-6/+0
| | | | | Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Joel Stanley <joel@jms.id.au>
* fsi: master-gpio: Add more tracepointsBenjamin Herrenschmidt2018-07-121-6/+10
| | | | | | | | | | | This adds a few more tracepoints that have proven useful when debugging issues with the FSI bus. This also makes echo_delay() use clock_zeros() instead of open-code it in order to share the tracepoint. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Joel Stanley <joel@jms.id.au>
* fsi: master-gpio: Add support for link_configBenjamin Herrenschmidt2018-07-121-2/+25
| | | | | | | To configure the send and echo delays Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Joel Stanley <joel@jms.id.au>
* fsi: master-gpio: Rename and adjust send delayBenjamin Herrenschmidt2018-07-121-3/+6
| | | | | | | | | What the driver called "FSI_GPIO_PRIME_SLAVE_CLOCKS" is what the FSI spec calls tSendDelay and should be 16 clocks by default. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Joel Stanley <joel@jms.id.au>
* fsi: Add mechanism to set the tSendDelay and tEchoDelay valuesBenjamin Herrenschmidt2018-07-122-18/+93
| | | | | | | | | | | | | | | Those values control the amount of "dummy" clocks between commands and between a command and its response. This adds a way to configure them from sysfs (to be later extended to defaults in the device-tree). The default remains 16 (the HW default). This is only supported if the backend supports the new link_config() callback to configure the generation of those delays. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Joel Stanley <joel@jms.id.au> ---
* fsi: Move code around to avoid forward declarationBenjamin Herrenschmidt2018-07-121-48/+46
| | | | | | | | Move fsi_slave_set_smode() and its helpers to before it's first user and remove the corresponding forward declaration. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Joel Stanley <joel@jms.id.au>
* fsi: sbefifo: Fix checker warning about late NULL checkBenjamin Herrenschmidt2018-07-121-2/+5
| | | | | | | "dev" is dereferences before it's checked. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi/sbefifo: Add dependency on OF_ADDRESSGuenter Roeck2018-07-121-0/+1
| | | | | | | | | | | | | The driver calls of_platform_device_create() which is only available if OF_ADDRESS is enabled. When building sparc64 images, this results in ERROR: "of_platform_device_create" [drivers/fsi/fsi-sbefifo.ko] undefined! Fixes: 9f4a8a2d7f9d ("fsi/sbefifo: Add driver for the SBE FIFO") Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: sbefifo: Add missing mutex_unlockEddie James2018-07-121-0/+1
| | | | | | | | There was no unlock of the FFDC mutex. Fixes: 9f4a8a2d7f9d ("fsi/sbefifo: Add driver for the SBE FIFO") Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: scom: Major overhaulBenjamin Herrenschmidt2018-06-181-30/+394
| | | | | | | | | | | | | | | This was too hard to split ... this adds a number of features to the SCOM user interface: - Support for indirect SCOMs - read()/write() interface now handle errors and retries - New ioctl() "raw" interface for use by debuggers Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com> Reviewed-by: Alistair Popple <alistair@popple.id.au>
* fsi: scom: Add register definitionsBenjamin Herrenschmidt2018-06-181-1/+18
| | | | | | | | Add a few more register and bit definitions, also define and use SCOM_READ_CMD (which is 0 but it makes the code clearer) Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
* fsi: scom: Fixup endian annotationsBenjamin Herrenschmidt2018-06-181-5/+4
| | | | | | | | Use the proper annotated type __be32 and fixup the accessor used for get_scom() Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
* fsi: scom: Whitespace fixesBenjamin Herrenschmidt2018-06-181-4/+4
| | | | | | | No functional changes Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
* fsi: scom: Add mutex around FSI2PIB accessesBenjamin Herrenschmidt2018-06-181-7/+18
| | | | | | | | | Otherwise, multiple clients can open the driver and attempt to access the PIB at the same time, thus clobbering each other in the process. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
* fsi: core: Fix sparse warningsJoel Stanley2018-06-181-10/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:210:9: warning: cast to restricted __be32 fsi-core.c:606:15: warning: incorrect type in assignment (different base types) fsi-core.c:606:15: expected unsigned int [unsigned] [assigned] [usertype] smode fsi-core.c:606:15: got restricted __be32 [usertype] <noident> fsi-core.c:492:28: warning: expression using sizeof(void) fsi-core.c:520:29: warning: expression using sizeof(void) fsi-core.c:682:19: warning: cast to restricted __be32 fsi-core.c:682:19: warning: cast to restricted __be32 fsi-core.c:682:19: warning: cast to restricted __be32 fsi-core.c:682:19: warning: cast to restricted __be32 fsi-core.c:682:19: warning: cast to restricted __be32 fsi-core.c:682:19: warning: cast to restricted __be32 fsi-core.c:706:24: warning: incorrect type in assignment (different base types) fsi-core.c:706:24: expected unsigned int [unsigned] [usertype] llmode fsi-core.c:706:24: got restricted __be32 [usertype] <noident> Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi: master-hub: Fix sparse warningsJoel Stanley2018-06-181-2/+3
| | | | | | | | | | | | 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>
* fsi: sbefifo: Fix sparse warningsJoel Stanley2018-06-181-2/+3
| | | | | | | | | | | | | | | 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>
* fsi: sbefifo: Remove unneeded semicolonBenjamin Herrenschmidt2018-06-141-1/+1
| | | | | | Spotted by kbuild-test-bot Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* fsi/sbefifo: Add driver for the SBE FIFOBenjamin Herrenschmidt2018-06-123-0/+1013
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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> ---
* fsi: scom: Remove PIB reset during probeEddie James2018-06-121-8/+0
| | | | | | | | | | 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>
* fsi/master-gpio: Replace bit_bit lock with IRQ disable/enableJeremy Kerr2018-06-121-25/+23
| | | | | | | | | | | | | | | | 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>
* fsi/fsi-master-gpio: More error handling cleanupBenjamin Herrenschmidt2018-06-121-21/+5
| | | | | | | | | 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>
* fsi/fsi-master-gpio: Implement CRC error recoveryBenjamin Herrenschmidt2018-06-121-18/+72
| | | | | | | | | | | | | | | | | | | | | 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.
* fsi/gpio: Use relative-addressing commandsJeremy Kerr2018-06-121-11/+91
| | | | | | | | | | | | 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>
* fsi/gpio: Include command build in locked sectionJeremy Kerr2018-06-121-7/+18
| | | | | | | | | | 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>
* fsi/fsi-master-gpio: Delay sampling of FSI data inputBenjamin Herrenschmidt2018-06-121-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* fsi/fsi-master-gpio: Reduce dpoll clocksBenjamin Herrenschmidt2018-06-121-2/+3
| | | | | | | | | | | | | | | | | 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>
* fsi/fsi-master-gpio: Reduce turnaround clocksBenjamin Herrenschmidt2018-06-121-1/+1
| | | | | | | | | | | | | | | | | 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>
* fsi/fsi-master-gpio: Add "no-gpio-delays" optionBenjamin Herrenschmidt2018-06-121-4/+16
| | | | | | | | | | | | | | | | | 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>
* fsi/fsi-master-gpio: Sample input data on different clock phaseBenjamin Herrenschmidt2018-06-121-3/+5
| | | | | | | | | | | | | | 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>
* fsi: gpio: Use a mutex to protect transfersJeremy Kerr2018-06-121-22/+64
| | | | | | | | | | | 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>
* fsi: gpio: Remove unused 'id' variableAndrew Jeffery2018-06-121-2/+1
| | | | | | 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>
* fsi: gpio: Trace busy countAndrew Jeffery2018-06-121-0/+3
| | | | | | | | | | | | 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>
* fsi: core: Add check for master property no-scan-on-initChristopher Bostic2018-03-141-1/+4
| | | | | | | | | | | | 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>
* fsi: master: Clarify master lifetimes & fix use-after-free in hub masterJeremy Kerr2018-03-142-3/+33
| | | | | | | | | | | | | | 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>
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