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path: root/drivers/fsi
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2018-03-14fsi: core: Add check for master property no-scan-on-initChristopher Bostic
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>
2018-03-14fsi: master: Clarify master lifetimes & fix use-after-free in hub masterJeremy Kerr
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>
2018-03-14fsi: core: Reduce console output during normal scanChristopher Bostic
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>
2018-03-14fsi: Match fsi slaves and engines to available dt nodesJeremy Kerr
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>
2018-03-14fsi: Fix one and two byte bus reads/writesEddie James
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>
2018-03-14fsi: master-gpio: Add external modeJeremy Kerr
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>
2018-03-14fsi: master-gpio: Add locking during break and link enableJeremy Kerr
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>
2018-03-14fsi: Add fsi_master_rescan()Jeremy Kerr
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>
2017-12-07fsi: Make FSI a menuconfig to ease disabling it allVincent Legoll
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>
2017-10-04drivers/fsi: make a couple of functions staticColin Ian King
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>
2017-08-28drivers/fsi/scom: Remove reset before every putscomEdward A. James
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>
2017-08-28drivers/fsi: add const to bin_attribute structuresBhumika Goyal
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>
2017-07-17drivers/fsi: fix fsi_slave_mode prototypeArnd Bergmann
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: 2b37c3e285f9 ("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>
2017-07-17fsi: core: register with postcore_initcallJoel Stanley
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: 0508ad1fff11 ("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>
2017-06-09drivers/fsi: Add module license to core driverChristopher Bostic
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>
2017-06-09drivers/fsi: Use asynchronous slave modeJeremy Kerr
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>
2017-06-09drivers/fsi: Add hub master supportChristopher Bostic
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>
2017-06-09drivers/fsi: Add SCOM FSI client device driverChristopher Bostic
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>
2017-06-09drivers/fsi/gpio: Add tracepoints for GPIO masterJeremy Kerr
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>
2017-06-09drivers/fsi: Add GPIO based FSI masterChristopher Bostic
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>
2017-06-09drivers/fsi: Add error handling for slaveJeremy Kerr
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>
2017-06-09drivers/fsi: Add tracepoints for low-level operationsJeremy Kerr
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>
2017-06-09drivers/fsi: expose direct-access slave APIJeremy Kerr
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>
2017-06-09drivers/fsi: Add sysfs files for FSI master & slave accessesJeremy Kerr
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>
2017-06-09drivers/fsi: Add client driver register utilitiesChristopher Bostic
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>
2017-06-09drivers/fsi: Add master unscanChristopher Bostic
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>
2017-06-09drivers/fsi: Add device read/write/peek APIJeremy Kerr
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>
2017-06-09drivers/fsi: scan slaves & register devicesJeremy Kerr
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>
2017-06-09drivers/fsi: Set slave SMODE to init communicationChristopher Bostic
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>
2017-06-09drivers/fsi: Implement slave initialisationJeremy Kerr
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>
2017-06-09drivers/fsi: Set up links for slave communicationChristopher Bostic
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>
2017-06-09drivers/fsi: Add slave & master read/write APIsJeremy Kerr
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>
2017-06-09drivers/fsi: Add empty master scanJeremy Kerr
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>
2017-06-09drivers/fsi: Add slave definitionJeremy Kerr
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>
2017-06-09drivers/fsi: Add fsi master definitionJeremy Kerr
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>
2017-02-10drivers/fsi: add driver to device matchesJeremy Kerr
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>
2017-02-10drivers/fsi: Add empty fsi bus definitionsJeremy Kerr
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>