Commit c94085f5 authored by Mark Brown's avatar Mark Brown

Merge branches 'topic/core', 'topic/slave' and 'fix/doc' of...

Merge branches 'topic/core', 'topic/slave' and 'fix/doc' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-master
SPI (Serial Peripheral Interface) busses
SPI busses can be described with a node for the SPI master device
and a set of child nodes for each SPI slave on the bus. For this
discussion, it is assumed that the system's SPI controller is in
SPI master mode. This binding does not describe SPI controllers
in slave mode.
SPI busses can be described with a node for the SPI controller device
and a set of child nodes for each SPI slave on the bus. The system's SPI
controller may be described for use in SPI master mode or in SPI slave mode,
but not for both at the same time.
The SPI master node requires the following properties:
The SPI controller node requires the following properties:
- compatible - Name of SPI bus controller following generic names
recommended practice.
In master mode, the SPI controller node requires the following additional
properties:
- #address-cells - number of cells required to define a chip select
address on the SPI bus.
- #size-cells - should be zero.
- compatible - name of SPI bus controller following generic names
recommended practice.
In slave mode, the SPI controller node requires one additional property:
- spi-slave - Empty property.
No other properties are required in the SPI bus node. It is assumed
that a driver for an SPI bus device will understand that it is an SPI bus.
However, the binding does not attempt to define the specific method for
......@@ -21,7 +27,7 @@ assumption that board specific platform code will be used to manage
chip selects. Individual drivers can define additional properties to
support describing the chip select layout.
Optional properties:
Optional properties (master mode only):
- cs-gpios - gpios chip select.
- num-cs - total number of chipselects.
......@@ -41,28 +47,36 @@ cs1 : native
cs2 : &gpio1 1 0
cs3 : &gpio1 2 0
SPI slave nodes must be children of the SPI master node and can
contain the following properties.
- reg - (required) chip select address of device.
- compatible - (required) name of SPI device following generic names
recommended practice.
- spi-max-frequency - (required) Maximum SPI clocking speed of device in Hz.
- spi-cpol - (optional) Empty property indicating device requires
inverse clock polarity (CPOL) mode.
- spi-cpha - (optional) Empty property indicating device requires
shifted clock phase (CPHA) mode.
- spi-cs-high - (optional) Empty property indicating device requires
chip select active high.
- spi-3wire - (optional) Empty property indicating device requires
3-wire mode.
- spi-lsb-first - (optional) Empty property indicating device requires
LSB first mode.
- spi-tx-bus-width - (optional) The bus width (number of data wires) that is
used for MOSI. Defaults to 1 if not present.
- spi-rx-bus-width - (optional) The bus width (number of data wires) that is
used for MISO. Defaults to 1 if not present.
- spi-rx-delay-us - (optional) Microsecond delay after a read transfer.
- spi-tx-delay-us - (optional) Microsecond delay after a write transfer.
SPI slave nodes must be children of the SPI controller node.
In master mode, one or more slave nodes (up to the number of chip selects) can
be present. Required properties are:
- compatible - Name of SPI device following generic names recommended
practice.
- reg - Chip select address of device.
- spi-max-frequency - Maximum SPI clocking speed of device in Hz.
In slave mode, the (single) slave node is optional.
If present, it must be called "slave". Required properties are:
- compatible - Name of SPI device following generic names recommended
practice.
All slave nodes can contain the following optional properties:
- spi-cpol - Empty property indicating device requires inverse clock
polarity (CPOL) mode.
- spi-cpha - Empty property indicating device requires shifted clock
phase (CPHA) mode.
- spi-cs-high - Empty property indicating device requires chip select
active high.
- spi-3wire - Empty property indicating device requires 3-wire mode.
- spi-lsb-first - Empty property indicating device requires LSB first mode.
- spi-tx-bus-width - The bus width (number of data wires) that is used for MOSI.
Defaults to 1 if not present.
- spi-rx-bus-width - The bus width (number of data wires) that is used for MISO.
Defaults to 1 if not present.
- spi-rx-delay-us - Microsecond delay after a read transfer.
- spi-tx-delay-us - Microsecond delay after a write transfer.
Some SPI controllers and devices support Dual and Quad SPI transfer mode.
It allows data in the SPI system to be transferred using 2 wires (DUAL) or 4
......
......@@ -62,8 +62,8 @@ chips described as using "three wire" signaling: SCK, data, nCSx.
(That data line is sometimes called MOMI or SISO.)
Microcontrollers often support both master and slave sides of the SPI
protocol. This document (and Linux) currently only supports the master
side of SPI interactions.
protocol. This document (and Linux) supports both the master and slave
sides of SPI interactions.
Who uses it? On what kinds of systems?
......@@ -154,9 +154,8 @@ control audio interfaces, present touchscreen sensors as input interfaces,
or monitor temperature and voltage levels during industrial processing.
And those might all be sharing the same controller driver.
A "struct spi_device" encapsulates the master-side interface between
those two types of driver. At this writing, Linux has no slave side
programming interface.
A "struct spi_device" encapsulates the controller-side interface between
those two types of drivers.
There is a minimal core of SPI programming interfaces, focussing on
using the driver model to connect controller and protocol drivers using
......@@ -177,10 +176,24 @@ shows up in sysfs in several locations:
/sys/bus/spi/drivers/D ... driver for one or more spi*.* devices
/sys/class/spi_master/spiB ... symlink (or actual device node) to
a logical node which could hold class related state for the
controller managing bus "B". All spiB.* devices share one
a logical node which could hold class related state for the SPI
master controller managing bus "B". All spiB.* devices share one
physical SPI bus segment, with SCLK, MOSI, and MISO.
/sys/devices/.../CTLR/slave ... virtual file for (un)registering the
slave device for an SPI slave controller.
Writing the driver name of an SPI slave handler to this file
registers the slave device; writing "(null)" unregisters the slave
device.
Reading from this file shows the name of the slave device ("(null)"
if not registered).
/sys/class/spi_slave/spiB ... symlink (or actual device node) to
a logical node which could hold class related state for the SPI
slave controller on bus "B". When registered, a single spiB.*
device is present here, possible sharing the physical SPI bus
segment with other SPI slave devices.
Note that the actual location of the controller's class state depends
on whether you enabled CONFIG_SYSFS_DEPRECATED or not. At this time,
the only class-specific state is the bus number ("B" in "spiB"), so
......
......@@ -784,6 +784,30 @@ config SPI_TLE62X0
endif # SPI_MASTER
# (slave support would go here)
#
# SLAVE side ... listening to other SPI masters
#
config SPI_SLAVE
bool "SPI slave protocol handlers"
help
If your system has a slave-capable SPI controller, you can enable
slave protocol handlers.
if SPI_SLAVE
config SPI_SLAVE_TIME
tristate "SPI slave handler reporting boot up time"
help
SPI slave handler responding with the time of reception of the last
SPI message.
config SPI_SLAVE_SYSTEM_CONTROL
tristate "SPI slave handler controlling system state"
help
SPI slave handler to allow remote control of system reboot, power
off, halt, and suspend.
endif # SPI_SLAVE
endif # SPI
......@@ -105,3 +105,7 @@ obj-$(CONFIG_SPI_XILINX) += spi-xilinx.o
obj-$(CONFIG_SPI_XLP) += spi-xlp.o
obj-$(CONFIG_SPI_XTENSA_XTFPGA) += spi-xtensa-xtfpga.o
obj-$(CONFIG_SPI_ZYNQMP_GQSPI) += spi-zynqmp-gqspi.o
# SPI slave protocol handlers
obj-$(CONFIG_SPI_SLAVE_TIME) += spi-slave-time.o
obj-$(CONFIG_SPI_SLAVE_SYSTEM_CONTROL) += spi-slave-system-control.o
/*
* SPI slave handler controlling system state
*
* This SPI slave handler allows remote control of system reboot, power off,
* halt, and suspend.
*
* Copyright (C) 2016-2017 Glider bvba
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Usage (assuming /dev/spidev2.0 corresponds to the SPI master on the remote
* system):
*
* # reboot='\x7c\x50'
* # poweroff='\x71\x3f'
* # halt='\x38\x76'
* # suspend='\x1b\x1b'
* # spidev_test -D /dev/spidev2.0 -p $suspend # or $reboot, $poweroff, $halt
*/
#include <linux/completion.h>
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/suspend.h>
#include <linux/spi/spi.h>
/*
* The numbers are chosen to display something human-readable on two 7-segment
* displays connected to two 74HC595 shift registers
*/
#define CMD_REBOOT 0x7c50 /* rb */
#define CMD_POWEROFF 0x713f /* OF */
#define CMD_HALT 0x3876 /* HL */
#define CMD_SUSPEND 0x1b1b /* ZZ */
struct spi_slave_system_control_priv {
struct spi_device *spi;
struct completion finished;
struct spi_transfer xfer;
struct spi_message msg;
__be16 cmd;
};
static
int spi_slave_system_control_submit(struct spi_slave_system_control_priv *priv);
static void spi_slave_system_control_complete(void *arg)
{
struct spi_slave_system_control_priv *priv = arg;
u16 cmd;
int ret;
if (priv->msg.status)
goto terminate;
cmd = be16_to_cpu(priv->cmd);
switch (cmd) {
case CMD_REBOOT:
dev_info(&priv->spi->dev, "Rebooting system...\n");
kernel_restart(NULL);
case CMD_POWEROFF:
dev_info(&priv->spi->dev, "Powering off system...\n");
kernel_power_off();
break;
case CMD_HALT:
dev_info(&priv->spi->dev, "Halting system...\n");
kernel_halt();
break;
case CMD_SUSPEND:
dev_info(&priv->spi->dev, "Suspending system...\n");
pm_suspend(PM_SUSPEND_MEM);
break;
default:
dev_warn(&priv->spi->dev, "Unknown command 0x%x\n", cmd);
break;
}
ret = spi_slave_system_control_submit(priv);
if (ret)
goto terminate;
return;
terminate:
dev_info(&priv->spi->dev, "Terminating\n");
complete(&priv->finished);
}
static
int spi_slave_system_control_submit(struct spi_slave_system_control_priv *priv)
{
int ret;
spi_message_init_with_transfers(&priv->msg, &priv->xfer, 1);
priv->msg.complete = spi_slave_system_control_complete;
priv->msg.context = priv;
ret = spi_async(priv->spi, &priv->msg);
if (ret)
dev_err(&priv->spi->dev, "spi_async() failed %d\n", ret);
return ret;
}
static int spi_slave_system_control_probe(struct spi_device *spi)
{
struct spi_slave_system_control_priv *priv;
int ret;
priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->spi = spi;
init_completion(&priv->finished);
priv->xfer.rx_buf = &priv->cmd;
priv->xfer.len = sizeof(priv->cmd);
ret = spi_slave_system_control_submit(priv);
if (ret)
return ret;
spi_set_drvdata(spi, priv);
return 0;
}
static int spi_slave_system_control_remove(struct spi_device *spi)
{
struct spi_slave_system_control_priv *priv = spi_get_drvdata(spi);
spi_slave_abort(spi);
wait_for_completion(&priv->finished);
return 0;
}
static struct spi_driver spi_slave_system_control_driver = {
.driver = {
.name = "spi-slave-system-control",
},
.probe = spi_slave_system_control_probe,
.remove = spi_slave_system_control_remove,
};
module_spi_driver(spi_slave_system_control_driver);
MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
MODULE_DESCRIPTION("SPI slave handler controlling system state");
MODULE_LICENSE("GPL v2");
/*
* SPI slave handler reporting uptime at reception of previous SPI message
*
* This SPI slave handler sends the time of reception of the last SPI message
* as two 32-bit unsigned integers in binary format and in network byte order,
* representing the number of seconds and fractional seconds (in microseconds)
* since boot up.
*
* Copyright (C) 2016-2017 Glider bvba
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Usage (assuming /dev/spidev2.0 corresponds to the SPI master on the remote
* system):
*
* # spidev_test -D /dev/spidev2.0 -p dummy-8B
* spi mode: 0x0
* bits per word: 8
* max speed: 500000 Hz (500 KHz)
* RX | 00 00 04 6D 00 09 5B BB ...
* ^^^^^ ^^^^^^^^
* seconds microseconds
*/
#include <linux/completion.h>
#include <linux/module.h>
#include <linux/sched/clock.h>
#include <linux/spi/spi.h>
struct spi_slave_time_priv {
struct spi_device *spi;
struct completion finished;
struct spi_transfer xfer;
struct spi_message msg;
__be32 buf[2];
};
static int spi_slave_time_submit(struct spi_slave_time_priv *priv);
static void spi_slave_time_complete(void *arg)
{
struct spi_slave_time_priv *priv = arg;
int ret;
ret = priv->msg.status;
if (ret)
goto terminate;
ret = spi_slave_time_submit(priv);
if (ret)
goto terminate;
return;
terminate:
dev_info(&priv->spi->dev, "Terminating\n");
complete(&priv->finished);
}
static int spi_slave_time_submit(struct spi_slave_time_priv *priv)
{
u32 rem_us;
int ret;
u64 ts;
ts = local_clock();
rem_us = do_div(ts, 1000000000) / 1000;
priv->buf[0] = cpu_to_be32(ts);
priv->buf[1] = cpu_to_be32(rem_us);
spi_message_init_with_transfers(&priv->msg, &priv->xfer, 1);
priv->msg.complete = spi_slave_time_complete;
priv->msg.context = priv;
ret = spi_async(priv->spi, &priv->msg);
if (ret)
dev_err(&priv->spi->dev, "spi_async() failed %d\n", ret);
return ret;
}
static int spi_slave_time_probe(struct spi_device *spi)
{
struct spi_slave_time_priv *priv;
int ret;
priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->spi = spi;
init_completion(&priv->finished);
priv->xfer.tx_buf = priv->buf;
priv->xfer.len = sizeof(priv->buf);
ret = spi_slave_time_submit(priv);
if (ret)
return ret;
spi_set_drvdata(spi, priv);
return 0;
}
static int spi_slave_time_remove(struct spi_device *spi)
{
struct spi_slave_time_priv *priv = spi_get_drvdata(spi);
spi_slave_abort(spi);
wait_for_completion(&priv->finished);
return 0;
}
static struct spi_driver spi_slave_time_driver = {
.driver = {
.name = "spi-slave-time",
},
.probe = spi_slave_time_probe,
.remove = spi_slave_time_remove,
};
module_spi_driver(spi_slave_time_driver);
MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
MODULE_DESCRIPTION("SPI slave reporting uptime at previous SPI message");
MODULE_LICENSE("GPL v2");
......@@ -1535,15 +1535,6 @@ static int of_spi_parse_dt(struct spi_master *master, struct spi_device *spi,
u32 value;
int rc;
/* Device address */
rc = of_property_read_u32(nc, "reg", &value);
if (rc) {
dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
nc->full_name, rc);
return rc;
}
spi->chip_select = value;
/* Mode (clock phase/polarity/etc.) */
if (of_find_property(nc, "spi-cpha", NULL))
spi->mode |= SPI_CPHA;
......@@ -1593,6 +1584,24 @@ static int of_spi_parse_dt(struct spi_master *master, struct spi_device *spi,
}
}
if (spi_controller_is_slave(master)) {
if (strcmp(nc->name, "slave")) {
dev_err(&master->dev, "%s is not called 'slave'\n",
nc->full_name);
return -EINVAL;
}
return 0;
}
/* Device address */
rc = of_property_read_u32(nc, "reg", &value);
if (rc) {
dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
nc->full_name, rc);
return rc;
}
spi->chip_select = value;
/* Device speed */
rc = of_property_read_u32(nc, "spi-max-frequency", &value);
if (rc) {
......@@ -1658,8 +1667,8 @@ of_register_spi_device(struct spi_master *master, struct device_node *nc)
* of_register_spi_devices() - Register child devices onto the SPI bus
* @master: Pointer to spi_master device
*
* Registers an spi_device for each child node of master node which has a 'reg'
* property.
* Registers an spi_device for each child node of controller node which
* represents a valid SPI slave.
*/
static void of_register_spi_devices(struct spi_master *master)
{
......@@ -1828,28 +1837,129 @@ static struct class spi_master_class = {
.dev_groups = spi_master_groups,
};
#ifdef CONFIG_SPI_SLAVE
/**
* spi_slave_abort - abort the ongoing transfer request on an SPI slave
* controller
* @spi: device used for the current transfer
*/
int spi_slave_abort(struct spi_device *spi)
{
struct spi_master *master = spi->master;
if (spi_controller_is_slave(master) && master->slave_abort)
return master->slave_abort(master);
return -ENOTSUPP;
}
EXPORT_SYMBOL_GPL(spi_slave_abort);
static int match_true(struct device *dev, void *data)
{
return 1;
}
static ssize_t spi_slave_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct spi_master *ctlr = container_of(dev, struct spi_master, dev);
struct device *child;
child = device_find_child(&ctlr->dev, NULL, match_true);
return sprintf(buf, "%s\n",
child ? to_spi_device(child)->modalias : NULL);
}
static ssize_t spi_slave_store(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
struct spi_master *ctlr = container_of(dev, struct spi_master, dev);
struct spi_device *spi;
struct device *child;
char name[32];
int rc;
rc = sscanf(buf, "%31s", name);
if (rc != 1 || !name[0])
return -EINVAL;
child = device_find_child(&ctlr->dev, NULL, match_true);
if (child) {
/* Remove registered slave */
device_unregister(child);
put_device(child);
}
if (strcmp(name, "(null)")) {
/* Register new slave */
spi = spi_alloc_device(ctlr);
if (!spi)
return -ENOMEM;
strlcpy(spi->modalias, name, sizeof(spi->modalias));
rc = spi_add_device(spi);
if (rc) {
spi_dev_put(spi);
return rc;
}
}
return count;
}
static DEVICE_ATTR(slave, 0644, spi_slave_show, spi_slave_store);
static struct attribute *spi_slave_attrs[] = {
&dev_attr_slave.attr,
NULL,
};
static const struct attribute_group spi_slave_group = {
.attrs = spi_slave_attrs,
};
static const struct attribute_group *spi_slave_groups[] = {
&spi_master_statistics_group,
&spi_slave_group,
NULL,
};
static struct class spi_slave_class = {
.name = "spi_slave",
.owner = THIS_MODULE,
.dev_release = spi_master_release,
.dev_groups = spi_slave_groups,
};
#else
extern struct class spi_slave_class; /* dummy */
#endif
/**
* spi_alloc_master - allocate SPI master controller
* __spi_alloc_controller - allocate an SPI master or slave controller
* @dev: the controller, possibly using the platform_bus
* @size: how much zeroed driver-private data to allocate; the pointer to this
* memory is in the driver_data field of the returned device,
* accessible with spi_master_get_devdata().
* @slave: flag indicating whether to allocate an SPI master (false) or SPI
* slave (true) controller
* Context: can sleep
*
* This call is used only by SPI master controller drivers, which are the
* This call is used only by SPI controller drivers, which are the
* only ones directly touching chip registers. It's how they allocate
* an spi_master structure, prior to calling spi_register_master().
*
* This must be called from context that can sleep.
*
* The caller is responsible for assigning the bus number and initializing
* the master's methods before calling spi_register_master(); and (after errors
* The caller is responsible for assigning the bus number and initializing the
* controller's methods before calling spi_register_master(); and (after errors
* adding the device) calling spi_master_put() to prevent a memory leak.
*
* Return: the SPI master structure on success, else NULL.
* Return: the SPI controller structure on success, else NULL.
*/
struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
struct spi_master *__spi_alloc_controller(struct device *dev,
unsigned int size, bool slave)
{
struct spi_master *master;
......@@ -1863,14 +1973,18 @@ struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
device_initialize(&master->dev);
master->bus_num = -1;
master->num_chipselect = 1;
master->dev.class = &spi_master_class;
master->slave = slave;
if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
master->dev.class = &spi_slave_class;
else
master->dev.class = &spi_master_class;
master->dev.parent = dev;
pm_suspend_ignore_children(&master->dev, true);
spi_master_set_devdata(master, &master[1]);
return master;
}
EXPORT_SYMBOL_GPL(spi_alloc_master);
EXPORT_SYMBOL_GPL(__spi_alloc_controller);
#ifdef CONFIG_OF
static int of_spi_register_master(struct spi_master *master)
......@@ -1946,9 +2060,11 @@ int spi_register_master(struct spi_master *master)
if (!dev)
return -ENODEV;
status = of_spi_register_master(master);
if (status)
return status;
if (!spi_controller_is_slave(master)) {
status = of_spi_register_master(master);
if (status)
return status;
}
/* even if it's just one always-selected device, there must
* be at least one chipselect
......@@ -1985,8 +2101,9 @@ int spi_register_master(struct spi_master *master)
status = device_add(&master->dev);
if (status < 0)
goto done;
dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
dynamic ? " (dynamic)" : "");
dev_dbg(dev, "registered %s %s%s\n",
spi_controller_is_slave(master) ? "slave" : "master",
dev_name(&master->dev), dynamic ? " (dynamic)" : "");
/* If we're using a queued driver, start the queue */
if (master->transfer)
......@@ -2021,7 +2138,7 @@ static void devm_spi_unregister(struct device *dev, void *res)
}
/**
* dev_spi_register_master - register managed SPI master controller
* devm_spi_register_master - register managed SPI master controller
* @dev: device managing SPI master
* @master: initialized master, originally from spi_alloc_master()
* Context: can sleep
......@@ -3159,6 +3276,9 @@ static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
dev = class_find_device(&spi_master_class, NULL, node,
__spi_of_master_match);
if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
dev = class_find_device(&spi_slave_class, NULL, node,
__spi_of_master_match);
if (!dev)
return NULL;
......@@ -3240,6 +3360,9 @@ static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev)
dev = class_find_device(&spi_master_class, NULL, adev,
spi_acpi_master_match);
if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
dev = class_find_device(&spi_slave_class, NULL, adev,
spi_acpi_master_match);
if (!dev)
return NULL;
......@@ -3312,6 +3435,12 @@ static int __init spi_init(void)
if (status < 0)
goto err2;
if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
status = class_register(&spi_slave_class);
if (status < 0)
goto err3;
}
if (IS_ENABLED(CONFIG_OF_DYNAMIC))
WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
if (IS_ENABLED(CONFIG_ACPI))
......@@ -3319,6 +3448,8 @@ static int __init spi_init(void)
return 0;
err3:
class_unregister(&spi_master_class);
err2:
bus_unregister(&spi_bus_type);
err1:
......
......@@ -29,8 +29,8 @@ struct spi_transfer;
struct spi_flash_read_message;
/*
* INTERFACES between SPI master-side drivers and SPI infrastructure.
* (There's no SPI slave support for Linux yet...)
* INTERFACES between SPI master-side drivers and SPI slave protocol handlers,
* and SPI infrastructure.
*/
extern struct bus_type spi_bus_type;
......@@ -311,6 +311,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
* @min_speed_hz: Lowest supported transfer speed
* @max_speed_hz: Highest supported transfer speed
* @flags: other constraints relevant to this driver
* @slave: indicates that this is an SPI slave controller
* @max_transfer_size: function that returns the max transfer size for
* a &spi_device; may be %NULL, so the default %SIZE_MAX will be used.
* @max_message_size: function that returns the max message size for
......@@ -374,6 +375,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
* @handle_err: the subsystem calls the driver to handle an error that occurs
* in the generic implementation of transfer_one_message().
* @unprepare_message: undo any work done by prepare_message().
* @slave_abort: abort the ongoing transfer request on an SPI slave controller
* @spi_flash_read: to support spi-controller hardwares that provide
* accelerated interface to read from flash devices.
* @spi_flash_can_dma: analogous to can_dma() interface, but for
......@@ -447,6 +449,9 @@ struct spi_master {
#define SPI_MASTER_MUST_TX BIT(4) /* requires tx */
#define SPI_MASTER_GPIO_SS BIT(5) /* GPIO CS must select slave */
/* flag indicating this is an SPI slave controller */
bool slave;
/*
* on some hardware transfer / message size may be constrained
* the limit may depend on device transfer settings
......@@ -539,6 +544,7 @@ struct spi_master {
struct spi_message *message);
int (*unprepare_message)(struct spi_master *master,
struct spi_message *message);
int (*slave_abort)(struct spi_master *spi);
int (*spi_flash_read)(struct spi_device *spi,
struct spi_flash_read_message *msg);
bool (*spi_flash_can_dma)(struct spi_device *spi,
......@@ -595,6 +601,11 @@ static inline void spi_master_put(struct spi_master *master)
put_device(&master->dev);
}
static inline bool spi_controller_is_slave(struct spi_master *ctlr)
{
return IS_ENABLED(CONFIG_SPI_SLAVE) && ctlr->slave;
}
/* PM calls that need to be issued by the driver */
extern int spi_master_suspend(struct spi_master *master);
extern int spi_master_resume(struct spi_master *master);
......@@ -605,8 +616,23 @@ extern void spi_finalize_current_message(struct spi_master *master);
extern void spi_finalize_current_transfer(struct spi_master *master);
/* the spi driver core manages memory for the spi_master classdev */
extern struct spi_master *
spi_alloc_master(struct device *host, unsigned size);
extern struct spi_master *__spi_alloc_controller(struct device *host,
unsigned int size, bool slave);
static inline struct spi_master *spi_alloc_master(struct device *host,
unsigned int size)
{
return __spi_alloc_controller(host, size, false);
}
static inline struct spi_master *spi_alloc_slave(struct device *host,
unsigned int size)
{
if (!IS_ENABLED(CONFIG_SPI_SLAVE))
return NULL;
return __spi_alloc_controller(host, size, true);
}
extern int spi_register_master(struct spi_master *master);
extern int devm_spi_register_master(struct device *dev,
......@@ -912,6 +938,7 @@ extern int spi_setup(struct spi_device *spi);
extern int spi_async(struct spi_device *spi, struct spi_message *message);
extern int spi_async_locked(struct spi_device *spi,
struct spi_message *message);
extern int spi_slave_abort(struct spi_device *spi);
static inline size_t
spi_max_message_size(struct spi_device *spi)
......
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