rmi_bus.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2011-2016 Synaptics Incorporated
* Copyright (c) 2011 Unixphere
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/list.h>
#include <linux/pm.h>
#include <linux/rmi.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/of.h>
#include "rmi_bus.h"
#include "rmi_driver.h"
static int debug_flags;
module_param(debug_flags, int, 0644);
MODULE_PARM_DESC(debug_flags, "control debugging information");
void rmi_dbg(int flags, struct device *dev, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
if (flags & debug_flags) {
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
dev_printk(KERN_DEBUG, dev, "%pV", &vaf);
va_end(args);
}
}
EXPORT_SYMBOL_GPL(rmi_dbg);
/*
* RMI Physical devices
*
* Physical RMI device consists of several functions serving particular
* purpose. For example F11 is a 2D touch sensor while F01 is a generic
* function present in every RMI device.
*/
static void rmi_release_device(struct device *dev)
{
struct rmi_device *rmi_dev = to_rmi_device(dev);
kfree(rmi_dev);
}
static const struct device_type rmi_device_type = {
.name = "rmi4_sensor",
.release = rmi_release_device,
};
bool rmi_is_physical_device(struct device *dev)
{
return dev->type == &rmi_device_type;
}
/**
* rmi_register_transport_device - register a transport device connection
* on the RMI bus. Transport drivers provide communication from the devices
* on a bus (such as SPI, I2C, and so on) to the RMI4 sensor.
*
* @xport: the transport device to register
*/
int rmi_register_transport_device(struct rmi_transport_dev *xport)
{
static atomic_t transport_device_count = ATOMIC_INIT(0);
struct rmi_device *rmi_dev;
int error;
rmi_dev = kzalloc(sizeof(struct rmi_device), GFP_KERNEL);
if (!rmi_dev)
return -ENOMEM;
device_initialize(&rmi_dev->dev);
rmi_dev->xport = xport;
rmi_dev->number = atomic_inc_return(&transport_device_count) - 1;
dev_set_name(&rmi_dev->dev, "rmi4-%02d", rmi_dev->number);
rmi_dev->dev.bus = &rmi_bus_type;
rmi_dev->dev.type = &rmi_device_type;
xport->rmi_dev = rmi_dev;
error = device_add(&rmi_dev->dev);
if (error)
goto err_put_device;
rmi_dbg(RMI_DEBUG_CORE, xport->dev,
"%s: Registered %s as %s.\n", __func__,
dev_name(rmi_dev->xport->dev), dev_name(&rmi_dev->dev));
return 0;
err_put_device:
put_device(&rmi_dev->dev);
return error;
}
EXPORT_SYMBOL_GPL(rmi_register_transport_device);
/**
* rmi_unregister_transport_device - unregister a transport device connection
* @xport: the transport driver to unregister
*
*/
void rmi_unregister_transport_device(struct rmi_transport_dev *xport)
{
struct rmi_device *rmi_dev = xport->rmi_dev;
device_del(&rmi_dev->dev);
put_device(&rmi_dev->dev);
}
EXPORT_SYMBOL(rmi_unregister_transport_device);
/* Function specific stuff */
static void rmi_release_function(struct device *dev)
{
struct rmi_function *fn = to_rmi_function(dev);
kfree(fn);
}
static const struct device_type rmi_function_type = {
.name = "rmi4_function",
.release = rmi_release_function,
};
bool rmi_is_function_device(struct device *dev)
{
return dev->type == &rmi_function_type;
}
static int rmi_function_match(struct device *dev, struct device_driver *drv)
{
struct rmi_function_handler *handler = to_rmi_function_handler(drv);
struct rmi_function *fn = to_rmi_function(dev);
return fn->fd.function_number == handler->func;
}
#ifdef CONFIG_OF
static void rmi_function_of_probe(struct rmi_function *fn)
{
char of_name[9];
struct device_node *node = fn->rmi_dev->xport->dev->of_node;
snprintf(of_name, sizeof(of_name), "rmi4-f%02x",
fn->fd.function_number);
fn->dev.of_node = of_get_child_by_name(node, of_name);
}
#else
static inline void rmi_function_of_probe(struct rmi_function *fn)
{}
#endif
static struct irq_chip rmi_irq_chip = {
.name = "rmi4",
};
static int rmi_create_function_irq(struct rmi_function *fn,
struct rmi_function_handler *handler)
{
struct rmi_driver_data *drvdata = dev_get_drvdata(&fn->rmi_dev->dev);
int i, error;
for (i = 0; i < fn->num_of_irqs; i++) {
set_bit(fn->irq_pos + i, fn->irq_mask);
fn->irq[i] = irq_create_mapping(drvdata->irqdomain,
fn->irq_pos + i);
irq_set_chip_data(fn->irq[i], fn);
irq_set_chip_and_handler(fn->irq[i], &rmi_irq_chip,
handle_simple_irq);
irq_set_nested_thread(fn->irq[i], 1);
error = devm_request_threaded_irq(&fn->dev, fn->irq[i], NULL,
handler->attention, IRQF_ONESHOT,
dev_name(&fn->dev), fn);
if (error) {
dev_err(&fn->dev, "Error %d registering IRQ\n", error);
return error;
}
}
return 0;
}
static int rmi_function_probe(struct device *dev)
{
struct rmi_function *fn = to_rmi_function(dev);
struct rmi_function_handler *handler =
to_rmi_function_handler(dev->driver);
int error;
rmi_function_of_probe(fn);
if (handler->probe) {
error = handler->probe(fn);
if (error)
return error;
}
if (fn->num_of_irqs && handler->attention) {
error = rmi_create_function_irq(fn, handler);
if (error)
return error;
}
return 0;
}
static int rmi_function_remove(struct device *dev)
{
struct rmi_function *fn = to_rmi_function(dev);
struct rmi_function_handler *handler =
to_rmi_function_handler(dev->driver);
if (handler->remove)
handler->remove(fn);
return 0;
}
int rmi_register_function(struct rmi_function *fn)
{
struct rmi_device *rmi_dev = fn->rmi_dev;
int error;
device_initialize(&fn->dev);
dev_set_name(&fn->dev, "%s.fn%02x",
dev_name(&rmi_dev->dev), fn->fd.function_number);
fn->dev.parent = &rmi_dev->dev;
fn->dev.type = &rmi_function_type;
fn->dev.bus = &rmi_bus_type;
error = device_add(&fn->dev);
if (error) {
dev_err(&rmi_dev->dev,
"Failed device_register function device %s\n",
dev_name(&fn->dev));
goto err_put_device;
}
rmi_dbg(RMI_DEBUG_CORE, &rmi_dev->dev, "Registered F%02X.\n",
fn->fd.function_number);
return 0;
err_put_device:
put_device(&fn->dev);
return error;
}
void rmi_unregister_function(struct rmi_function *fn)
{
int i;
rmi_dbg(RMI_DEBUG_CORE, &fn->dev, "Unregistering F%02X.\n",
fn->fd.function_number);
device_del(&fn->dev);
of_node_put(fn->dev.of_node);
put_device(&fn->dev);
for (i = 0; i < fn->num_of_irqs; i++)
irq_dispose_mapping(fn->irq[i]);
}
/**
* rmi_register_function_handler - register a handler for an RMI function
* @handler: RMI handler that should be registered.
* @module: pointer to module that implements the handler
* @mod_name: name of the module implementing the handler
*
* This function performs additional setup of RMI function handler and
* registers it with the RMI core so that it can be bound to
* RMI function devices.
*/
int __rmi_register_function_handler(struct rmi_function_handler *handler,
struct module *owner,
const char *mod_name)
{
struct device_driver *driver = &handler->driver;
int error;
driver->bus = &rmi_bus_type;
driver->owner = owner;
driver->mod_name = mod_name;
driver->probe = rmi_function_probe;
driver->remove = rmi_function_remove;
error = driver_register(driver);
if (error) {
pr_err("driver_register() failed for %s, error: %d\n",
driver->name, error);
return error;
}
return 0;
}
EXPORT_SYMBOL_GPL(__rmi_register_function_handler);
/**
* rmi_unregister_function_handler - unregister given RMI function handler
* @handler: RMI handler that should be unregistered.
*
* This function unregisters given function handler from RMI core which
* causes it to be unbound from the function devices.
*/
void rmi_unregister_function_handler(struct rmi_function_handler *handler)
{
driver_unregister(&handler->driver);
}
EXPORT_SYMBOL_GPL(rmi_unregister_function_handler);
/* Bus specific stuff */
static int rmi_bus_match(struct device *dev, struct device_driver *drv)
{
bool physical = rmi_is_physical_device(dev);
/* First see if types are not compatible */
if (physical != rmi_is_physical_driver(drv))
return 0;
return physical || rmi_function_match(dev, drv);
}
struct bus_type rmi_bus_type = {
.match = rmi_bus_match,
.name = "rmi4",
};
static struct rmi_function_handler *fn_handlers[] = {
&rmi_f01_handler,
#ifdef CONFIG_RMI4_F03
&rmi_f03_handler,
#endif
#ifdef CONFIG_RMI4_F11
&rmi_f11_handler,
#endif
#ifdef CONFIG_RMI4_F12
&rmi_f12_handler,
#endif
#ifdef CONFIG_RMI4_F30
&rmi_f30_handler,
#endif
#ifdef CONFIG_RMI4_F34
&rmi_f34_handler,
#endif
#ifdef CONFIG_RMI4_F3A
&rmi_f3a_handler,
#endif
#ifdef CONFIG_RMI4_F54
&rmi_f54_handler,
#endif
#ifdef CONFIG_RMI4_F55
&rmi_f55_handler,
#endif
};
static void __rmi_unregister_function_handlers(int start_idx)
{
int i;
for (i = start_idx; i >= 0; i--)
rmi_unregister_function_handler(fn_handlers[i]);
}
static void rmi_unregister_function_handlers(void)
{
__rmi_unregister_function_handlers(ARRAY_SIZE(fn_handlers) - 1);
}
static int rmi_register_function_handlers(void)
{
int ret;
int i;
for (i = 0; i < ARRAY_SIZE(fn_handlers); i++) {
ret = rmi_register_function_handler(fn_handlers[i]);
if (ret) {
pr_err("%s: error registering the RMI F%02x handler: %d\n",
__func__, fn_handlers[i]->func, ret);
goto err_unregister_function_handlers;
}
}
return 0;
err_unregister_function_handlers:
__rmi_unregister_function_handlers(i - 1);
return ret;
}
int rmi_of_property_read_u32(struct device *dev, u32 *result,
const char *prop, bool optional)
{
int retval;
u32 val = 0;
retval = of_property_read_u32(dev->of_node, prop, &val);
if (retval && (!optional && retval == -EINVAL)) {
dev_err(dev, "Failed to get %s value: %d\n",
prop, retval);
return retval;
}
*result = val;
return 0;
}
EXPORT_SYMBOL_GPL(rmi_of_property_read_u32);
static int __init rmi_bus_init(void)
{
int error;
error = bus_register(&rmi_bus_type);
if (error) {
pr_err("%s: error registering the RMI bus: %d\n",
__func__, error);
return error;
}
error = rmi_register_function_handlers();
if (error)
goto err_unregister_bus;
error = rmi_register_physical_driver();
if (error) {
pr_err("%s: error registering the RMI physical driver: %d\n",
__func__, error);
goto err_unregister_bus;
}
return 0;
err_unregister_bus:
bus_unregister(&rmi_bus_type);
return error;
}
module_init(rmi_bus_init);
static void __exit rmi_bus_exit(void)
{
/*
* We should only ever get here if all drivers are unloaded, so
* all we have to do at this point is unregister ourselves.
*/
rmi_unregister_physical_driver();
rmi_unregister_function_handlers();
bus_unregister(&rmi_bus_type);
}
module_exit(rmi_bus_exit);
MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com");
MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com");
MODULE_DESCRIPTION("RMI bus");
MODULE_LICENSE("GPL");