linux/drivers/i3c/device.c
Uwe Kleine-König 7456fea589 i3c: Handle drivers without probe or remove callback
A registered driver without a probe callback doesn't make sense, so
refuse to register such a driver. (Otherwise i3c_device_probe() yields a
NULL pointer exception.)

A driver without remove is possible, e.g. when all resources are freed
using devm callbacks. So guard the call to driver->remove by a check
for being non-NULL.

Note that the only in-tree i3c driver
(drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c) doesn't have a remove
callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210128091048.17006-1-u.kleine-koenig@pengutronix.de
2021-02-02 00:16:57 +01:00

286 lines
7.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2018 Cadence Design Systems Inc.
*
* Author: Boris Brezillon <boris.brezillon@bootlin.com>
*/
#include <linux/atomic.h>
#include <linux/bug.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include "internals.h"
/**
* i3c_device_do_priv_xfers() - do I3C SDR private transfers directed to a
* specific device
*
* @dev: device with which the transfers should be done
* @xfers: array of transfers
* @nxfers: number of transfers
*
* Initiate one or several private SDR transfers with @dev.
*
* This function can sleep and thus cannot be called in atomic context.
*
* Return: 0 in case of success, a negative error core otherwise.
*/
int i3c_device_do_priv_xfers(struct i3c_device *dev,
struct i3c_priv_xfer *xfers,
int nxfers)
{
int ret, i;
if (nxfers < 1)
return 0;
for (i = 0; i < nxfers; i++) {
if (!xfers[i].len || !xfers[i].data.in)
return -EINVAL;
}
i3c_bus_normaluse_lock(dev->bus);
ret = i3c_dev_do_priv_xfers_locked(dev->desc, xfers, nxfers);
i3c_bus_normaluse_unlock(dev->bus);
return ret;
}
EXPORT_SYMBOL_GPL(i3c_device_do_priv_xfers);
/**
* i3c_device_get_info() - get I3C device information
*
* @dev: device we want information on
* @info: the information object to fill in
*
* Retrieve I3C dev info.
*/
void i3c_device_get_info(struct i3c_device *dev,
struct i3c_device_info *info)
{
if (!info)
return;
i3c_bus_normaluse_lock(dev->bus);
if (dev->desc)
*info = dev->desc->info;
i3c_bus_normaluse_unlock(dev->bus);
}
EXPORT_SYMBOL_GPL(i3c_device_get_info);
/**
* i3c_device_disable_ibi() - Disable IBIs coming from a specific device
* @dev: device on which IBIs should be disabled
*
* This function disable IBIs coming from a specific device and wait for
* all pending IBIs to be processed.
*
* Return: 0 in case of success, a negative error core otherwise.
*/
int i3c_device_disable_ibi(struct i3c_device *dev)
{
int ret = -ENOENT;
i3c_bus_normaluse_lock(dev->bus);
if (dev->desc) {
mutex_lock(&dev->desc->ibi_lock);
ret = i3c_dev_disable_ibi_locked(dev->desc);
mutex_unlock(&dev->desc->ibi_lock);
}
i3c_bus_normaluse_unlock(dev->bus);
return ret;
}
EXPORT_SYMBOL_GPL(i3c_device_disable_ibi);
/**
* i3c_device_enable_ibi() - Enable IBIs coming from a specific device
* @dev: device on which IBIs should be enabled
*
* This function enable IBIs coming from a specific device and wait for
* all pending IBIs to be processed. This should be called on a device
* where i3c_device_request_ibi() has succeeded.
*
* Note that IBIs from this device might be received before this function
* returns to its caller.
*
* Return: 0 in case of success, a negative error core otherwise.
*/
int i3c_device_enable_ibi(struct i3c_device *dev)
{
int ret = -ENOENT;
i3c_bus_normaluse_lock(dev->bus);
if (dev->desc) {
mutex_lock(&dev->desc->ibi_lock);
ret = i3c_dev_enable_ibi_locked(dev->desc);
mutex_unlock(&dev->desc->ibi_lock);
}
i3c_bus_normaluse_unlock(dev->bus);
return ret;
}
EXPORT_SYMBOL_GPL(i3c_device_enable_ibi);
/**
* i3c_device_request_ibi() - Request an IBI
* @dev: device for which we should enable IBIs
* @req: setup requested for this IBI
*
* This function is responsible for pre-allocating all resources needed to
* process IBIs coming from @dev. When this function returns, the IBI is not
* enabled until i3c_device_enable_ibi() is called.
*
* Return: 0 in case of success, a negative error core otherwise.
*/
int i3c_device_request_ibi(struct i3c_device *dev,
const struct i3c_ibi_setup *req)
{
int ret = -ENOENT;
if (!req->handler || !req->num_slots)
return -EINVAL;
i3c_bus_normaluse_lock(dev->bus);
if (dev->desc) {
mutex_lock(&dev->desc->ibi_lock);
ret = i3c_dev_request_ibi_locked(dev->desc, req);
mutex_unlock(&dev->desc->ibi_lock);
}
i3c_bus_normaluse_unlock(dev->bus);
return ret;
}
EXPORT_SYMBOL_GPL(i3c_device_request_ibi);
/**
* i3c_device_free_ibi() - Free all resources needed for IBI handling
* @dev: device on which you want to release IBI resources
*
* This function is responsible for de-allocating resources previously
* allocated by i3c_device_request_ibi(). It should be called after disabling
* IBIs with i3c_device_disable_ibi().
*/
void i3c_device_free_ibi(struct i3c_device *dev)
{
i3c_bus_normaluse_lock(dev->bus);
if (dev->desc) {
mutex_lock(&dev->desc->ibi_lock);
i3c_dev_free_ibi_locked(dev->desc);
mutex_unlock(&dev->desc->ibi_lock);
}
i3c_bus_normaluse_unlock(dev->bus);
}
EXPORT_SYMBOL_GPL(i3c_device_free_ibi);
/**
* i3cdev_to_dev() - Returns the device embedded in @i3cdev
* @i3cdev: I3C device
*
* Return: a pointer to a device object.
*/
struct device *i3cdev_to_dev(struct i3c_device *i3cdev)
{
return &i3cdev->dev;
}
EXPORT_SYMBOL_GPL(i3cdev_to_dev);
/**
* dev_to_i3cdev() - Returns the I3C device containing @dev
* @dev: device object
*
* Return: a pointer to an I3C device object.
*/
struct i3c_device *dev_to_i3cdev(struct device *dev)
{
return container_of(dev, struct i3c_device, dev);
}
EXPORT_SYMBOL_GPL(dev_to_i3cdev);
/**
* i3c_device_match_id() - Returns the i3c_device_id entry matching @i3cdev
* @i3cdev: I3C device
* @id_table: I3C device match table
*
* Return: a pointer to an i3c_device_id object or NULL if there's no match.
*/
const struct i3c_device_id *
i3c_device_match_id(struct i3c_device *i3cdev,
const struct i3c_device_id *id_table)
{
struct i3c_device_info devinfo;
const struct i3c_device_id *id;
u16 manuf, part, ext_info;
bool rndpid;
i3c_device_get_info(i3cdev, &devinfo);
manuf = I3C_PID_MANUF_ID(devinfo.pid);
part = I3C_PID_PART_ID(devinfo.pid);
ext_info = I3C_PID_EXTRA_INFO(devinfo.pid);
rndpid = I3C_PID_RND_LOWER_32BITS(devinfo.pid);
for (id = id_table; id->match_flags != 0; id++) {
if ((id->match_flags & I3C_MATCH_DCR) &&
id->dcr != devinfo.dcr)
continue;
if ((id->match_flags & I3C_MATCH_MANUF) &&
id->manuf_id != manuf)
continue;
if ((id->match_flags & I3C_MATCH_PART) &&
(rndpid || id->part_id != part))
continue;
if ((id->match_flags & I3C_MATCH_EXTRA_INFO) &&
(rndpid || id->extra_info != ext_info))
continue;
return id;
}
return NULL;
}
EXPORT_SYMBOL_GPL(i3c_device_match_id);
/**
* i3c_driver_register_with_owner() - register an I3C device driver
*
* @drv: driver to register
* @owner: module that owns this driver
*
* Register @drv to the core.
*
* Return: 0 in case of success, a negative error core otherwise.
*/
int i3c_driver_register_with_owner(struct i3c_driver *drv, struct module *owner)
{
drv->driver.owner = owner;
drv->driver.bus = &i3c_bus_type;
if (!drv->probe) {
pr_err("Trying to register an i3c driver without probe callback\n");
return -EINVAL;
}
return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(i3c_driver_register_with_owner);
/**
* i3c_driver_unregister() - unregister an I3C device driver
*
* @drv: driver to unregister
*
* Unregister @drv.
*/
void i3c_driver_unregister(struct i3c_driver *drv)
{
driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(i3c_driver_unregister);