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path: root/drivers/fsi/fsi-master-gpio.c
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* fsi: Match fsi slaves and engines to available dt nodesJeremy Kerr2018-03-141-0/+4
| | | | | | | | | | | | | | | | | | | 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>
* fsi: master-gpio: Add external modeJeremy Kerr2018-03-141-2/+76
| | | | | | | | | | | | | | | | | | | 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>
* fsi: master-gpio: Add locking during break and link enableJeremy Kerr2018-03-141-0/+7
| | | | | | | | | | | | 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>
* drivers/fsi: Use asynchronous slave modeJeremy Kerr2017-06-091-0/+1
| | | | | | | | | | 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>
* drivers/fsi/gpio: Add tracepoints for GPIO masterJeremy Kerr2017-06-091-0/+9
| | | | | | | | 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>
* drivers/fsi: Add GPIO based FSI masterChristopher Bostic2017-06-091-0/+594
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>
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