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path: root/drivers/fsi/fsi-master-aspeed.c
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2023-09-13fsi: aspeed: Reset master errors after CFAM resetEddie James
[ Upstream commit 52300909f4670ac552bfeb33c1355b896eac8c06 ] It has been observed that sometimes the FSI master will return all 0xffs after a CFAM has been taken out of reset, without presenting any error. Resetting the FSI master errors resolves the issue. Fixes: 4a851d714ead ("fsi: aspeed: Support CFAM reset GPIO") Signed-off-by: Eddie James <eajames@linux.ibm.com> Link: https://lore.kernel.org/r/20230612195657.245125-8-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-21Merge tag 'fsi-for-v5.18' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/joel/fsi into char-misc-next Joel writes: FSI changes for v5.18 * Improvements in SCOM and OCC drivers for error handling and retries * Addition of tracepoints for initialisation path * API for setting long running SBE FIFO operations * tag 'fsi-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/joel/fsi: fsi: Add trace events in initialization path fsi: sbefifo: Implement FSI_SBEFIFO_READ_TIMEOUT_SECONDS ioctl fsi: sbefifo: Use specified value of start of response timeout fsi: occ: Improve response status checking fsi: scom: Remove retries in indirect scoms fsi: scom: Fix error handling
2022-02-21fsi: Add trace events in initialization pathEddie James
Add definitions for trace events to show the scanning flow. Signed-off-by: Eddie James <eajames@linux.ibm.com> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20220207161640.35605-1-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2022-02-04fsi: Aspeed: Fix a potential double freeChristophe JAILLET
A struct device can never be devm_alloc()'ed. Here, it is embedded in "struct fsi_master", and "struct fsi_master" is embedded in "struct fsi_master_aspeed". Since "struct device" is embedded, the data structure embedding it must be released with the release function, as is already done here. So use kzalloc() instead of devm_kzalloc() when allocating "aspeed" and update all error handling branches accordingly. This prevent a potential double free(). This also fix another issue if opb_readl() fails. Instead of a direct return, it now jumps in the error handling path. Fixes: 606397d67f41 ("fsi: Add ast2600 master driver") Suggested-by: Greg KH <gregkh@linuxfoundation.org> Suggested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: https://lore.kernel.org/r/2c123f8b0a40dc1a061fae982169fe030b4f47e6.1641765339.git.christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-04fsi: Aspeed: Reduce poll timeoutEddie James
The lengthy timeout previously used sometimes resulted in scheduling problems, detailed below. Therefore reduce the timeout to 500us. This timeout selection is supported by the benchmarks collected below with various clock dividers. This is purely the time spent polling (reported by ktime_get()). div 1: max:150us avg: 2us div 2: max:155us avg: 3us div 4: max:149us avg: 7us div 8: max:153us avg: 13us div 16: max:197us avg: 21us div 32: max:181us avg: 50us div 64: max:262us avg:100us Jan 22 01:27:21 rain27bmc kernel: rcu: INFO: rcu_sched self-detected stall on CPU Jan 22 01:27:21 rain27bmc kernel: rcu: 0-....: (2099 ticks this GP) idle=0ca/1/0x40000002 softirq=349573/349573 fqs=1048 Jan 22 01:27:21 rain27bmc kernel: (t=2100 jiffies g=841149 q=7163) Jan 22 01:27:21 rain27bmc kernel: NMI backtrace for cpu 0 Jan 22 01:27:21 rain27bmc kernel: CPU: 0 PID: 5959 Comm: ibm-read-vpd Not tainted 5.8.17-a9b4ea8 #1 Jan 22 01:27:21 rain27bmc kernel: Hardware name: Generic DT based system Jan 22 01:27:21 rain27bmc kernel: Backtrace: Jan 22 01:27:25 rain27bmc kernel: [<8010d92c>] (dump_backtrace) from [<8010db80>] (show_stack+0x20/0x24) ... Jan 22 01:27:25 rain27bmc kernel: [<8010130c>] (gic_handle_irq) from [<80100b0c>] (__irq_svc+0x6c/0x90) Jan 22 01:27:25 rain27bmc kernel: Exception stack(0xb79159b0 to 0xb79159f8) Jan 22 01:27:25 rain27bmc kernel: 59a0: 9e88e5d5 00000559 00000559 00000018 Jan 22 01:27:25 rain27bmc kernel: 59c0: 00000000 9f217c55 00000003 00000559 a0201c00 bfa4d048 bfa4d000 b7915a44 Jan 22 01:27:25 rain27bmc kernel: 59e0: 40e88f8a b7915a00 3254e553 80734924 80030113 ffffffff Jan 22 01:27:25 rain27bmc kernel: r9:b7914000 r8:a0201c00 r7:b79159e4 r6:ffffffff r5:80030113 r4:80734924 Jan 22 01:27:25 rain27bmc kernel: [<807348b4>] (__opb_read) from [<80734d98>] (aspeed_master_read+0xbc/0xcc) Jan 22 01:27:25 rain27bmc kernel: r10:00000004 r9:00000002 r8:80734cdc r7:bd33fa40 r6:00000004 r5:bd33f840 Jan 22 01:27:25 rain27bmc kernel: r4:00201c00 Jan 22 01:27:25 rain27bmc kernel: [<80734cdc>] (aspeed_master_read) from [<807320f0>] (fsi_master_read+0x6c/0x1bc) ... Signed-off-by: Eddie James <eajames@linux.ibm.com> Link: https://lore.kernel.org/r/20210211194846.35475-1-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-06-04fsi: aspeed: convert to devm_platform_ioremap_resourceYangtao Li
Use devm_platform_ioremap_resource() to simplify code. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Link: https://lore.kernel.org/r/20191228190631.26777-1-tiny.windzz@gmail.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-06-04fsi: aspeed: Emit fewer barriers in opb operationsJoel Stanley
When setting up a read or write to the OPB memory space, we must perform five or six AHB writes. The ordering of these up until the trigger write does not matter, so use writel_relaxed. The generated code goes from (Debian GCC 10.2.1-6): mov r8, r3 mcr 15, 0, sl, cr7, cr10, {4} str sl, [r6, #20] mcr 15, 0, sl, cr7, cr10, {4} str r3, [r6, #24] mcr 15, 0, sl, cr7, cr10, {4} str r1, [r6, #28] mcr 15, 0, sl, cr7, cr10, {4} str r2, [r6, #32] mcr 15, 0, sl, cr7, cr10, {4} mov r1, #1 str r1, [r6, #64] ; 0x40 mcr 15, 0, sl, cr7, cr10, {4} str r1, [r6, #4] to this: str r3, [r7, #20] str r2, [r7, #24] str r1, [r7, #28] str r3, [r7, #64] mov r8, #0 mcr 15, 0, r8, cr7, cr10, {4} str r3, [r7, #4] Signed-off-by: Joel Stanley <joel@jms.id.au> Acked-by: Jeremy Kerr <jk@ozlabs.org> Reviewed-by: Eddie James <eajames@linux.ibm.com> Tested-by: Eddie James <eajames@linux.ibm.com> Link: https://lore.kernel.org/r/20210223041737.171274-1-joel@jms.id.au Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-06-04fsi: Add missing MODULE_DEVICE_TABLEZou Wei
This patch adds missing MODULE_DEVICE_TABLE definition which generates correct modalias for automatic loading of this driver when it is built as an external module. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Link: https://lore.kernel.org/r/1620896249-52769-1-git-send-email-zou_wei@huawei.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-12-09fsi: Aspeed: Add mutex to protect HW accessEddie James
There is nothing to prevent multiple commands being executed simultaneously. Add a mutex to prevent this. Fixes: 606397d67f41 ("fsi: Add ast2600 master driver") Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Milton Miller <miltonm@us.ibm.com> Signed-off-by: Eddie James <eajames@linux.ibm.com> Signed-off-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20201120004929.185239-1-joel@jms.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-10fsi: aspeed: Support CFAM reset GPIOJoel Stanley
Systems have a line for restting the remote CFAM. This is not part of the FSI master, but is associated with it, so it makes sense to include it in the master driver. This exposes a sysfs interface to reset the cfam, abstracting away the direction and polarity of the GPIO, as well as the timing of the reset pulse. Userspace will be blocked until the reset pulse is finished. The reset is hard coded to be in the range of (900, 1000) us. It was observed with a scope to regularly be just over 1ms. If the device tree property is not preset the driver will silently continue. Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Link: https://lore.kernel.org/r/20200728025527.174503-6-joel@jms.id.au Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-09-10fsi: aspeed: Add module param for bus divisorJoel Stanley
For testing and hardware debugging a user may wish to override the divisor at runtime. By setting fsi_master_aspeed.bus_div=N, the divisor will be set to N, if 0 < N <= 0x3ff. This is a module parameter and not a device tree option as it will only need to be set when testing or debugging. Reviewed-by: Eddie James <eajames@linux.ibm.com> Link: https://lore.kernel.org/r/20200728025527.174503-5-joel@jms.id.au Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-09-10fsi: aspeed: Run the bus at maximum speedJoel Stanley
Testing of Tacoma has shown that the ASPEED master can be run at maximum speed. The exception is when wired externally with a cable, in which case we use a divisor of two to ensure reliable operation. Reviewed-by: Eddie James <eajames@linux.ibm.com> Link: https://lore.kernel.org/r/20200728025527.174503-4-joel@jms.id.au Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-09-10fsi: aspeed: Support cabled FSIJoel Stanley
Some FSI capable systems have internal FSI signals, and some have external cabled FSI. Software can detect which machine this is by reading a jumper GPIO, and also control which pins the signals are routed to through a mux GPIO. This attempts to find the GPIOs at probe time. If they are not present in the device tree the driver will not error and continue as before. The mux GPIO is owned by the FSI driver to ensure it is not modified at runtime. The routing jumper obtained as non-exclusive to allow other software to inspect it's state. Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Link: https://lore.kernel.org/r/20200728025527.174503-3-joel@jms.id.au Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-09-10fsi: master: Remove link enable read-backEddie James
Both the Aspeed and hub masters read back the link enable register after enabling the link, but this is unnecessary, so remove it. Signed-off-by: Eddie James <eajames@linux.ibm.com> Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-09-10fsi: master: Add boolean parameter to link_enable functionEddie James
Add the ability to disable a link with a boolean parameter to the link_enable function. This is necessary so that the master can disable links that it isn't using; for example, links to slaves that fail initialization. Signed-off-by: Eddie James <eajames@linux.ibm.com> Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-09-10fsi: aspeed: Enable 23-bit addressingEddie James
In order to access more than the second hub link, 23-bit addressing is required. The core provides the highest two bits of address as the slave ID to the master. Signed-off-by: Eddie James <eajames@linux.ibm.com> Acked-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-11-08fsi: aspeed: Fix OPB0 byte order register valuesAndrew Jeffery
The data byte order selection registers in the APB2OPB primarily expose some internal plumbing necessary to get correct write accesses onto the OPB. OPB write cycles require "data mirroring" across the 32-bit data bus to support variable data width slaves that don't implement "byte enables". For slaves that do implement byte enables the master can signal which bytes on the data bus the slave should consider valid. The data mirroring behaviour is specified by the following table: +-----------------+----------+-----------------------------------+ | | | 32-bit Data Bus | +---------+-------+----------+---------+---------+-------+-------+ | | | | | | | | | ABus | Mn_BE | Request | Dbus | Dbus | Dbus | Dbus | | (30:31) | (0:3) | Transfer | 0:7 | 8:15 | 16:23 | 24:31 | | | | Size | byte0 | byte1 | byte2 | byte3 | +---------+-------+----------+---------+---------+-------+-------+ | 00 | 1111 | fullword | byte0 | byte1 | byte2 | byte3 | +---------+-------+----------+---------+---------+-------+-------+ | 00 | 1110 | halfword | byte0 | byte1 | byte2 | | +---------+-------+----------+---------+---------+-------+-------+ | 01 | 0111 | byte | _byte1_ | byte1 | byte2 | byte3 | +---------+-------+----------+---------+---------+-------+-------+ | 00 | 1100 | halfword | byte0 | byte1 | | | +---------+-------+----------+---------+---------+-------+-------+ | 01 | 0110 | byte | _byte1_ | byte1 | byte2 | | +---------+-------+----------+---------+---------+-------+-------+ | 10 | 0011 | halfword | _byte2_ | _byte3_ | byte2 | byte3 | +---------+-------+----------+---------+---------+-------+-------+ | 00 | 1000 | byte | byte0 | | | | +---------+-------+----------+---------+---------+-------+-------+ | 01 | 0100 | byte | _byte1_ | byte1 | | | +---------+-------+----------+---------+---------+-------+-------+ | 10 | 0010 | byte | _byte2_ | | byte2 | | +---------+-------+----------+---------+---------+-------+-------+ | 11 | 0001 | byte | _byte3_ | _byte3_ | | byte3 | +---------+-------+----------+---------+---------+-------+-------+ Mirrored data values are highlighted by underscores in the Dbus columns. The values in the ABus and Request Transfer Size columns correspond to values in the field names listed in the write data order select register descriptions. Similar configuration registers are exposed for reads which enables the secondary purpose of configuring hardware endian conversions. It appears the data bus byte order is switched around in hardware so set the registers such that we can access the correct values for all widths. The values were determined by experimentation on hardware against fixed CFAM register values to configure the read data order, then in combination with the table above and the register layout documentation in the AST2600 datasheet performing write/read cycles to configure the write data order registers. Signed-off-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au> Acked-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20191108051945.7109-12-joel@jms.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-08fsi: aspeed: Add trace pointsJoel Stanley
These trace points help with debugging the FSI master. They show the low level reads, writes and error states of the master. Signed-off-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20191108051945.7109-11-joel@jms.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-08fsi: Add ast2600 master driverJoel Stanley
The ast2600 BMC has a pair of FSI masters in it, behind an AHB to OPB bridge. The master driver supports reads and writes of full words, half word and byte accesses to remote CFAMs. It can perform very basic error recovery through resetting of the FSI port when an error is detected, and the issuing of breaks and terms. Signed-off-by: Joel Stanley <joel@jms.id.au> Acked-by: Alistair Popple <alistair@popple.id.au> -- v2: - remove debugging - squash in fixes Link: https://lore.kernel.org/r/20191108051945.7109-10-joel@jms.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>