u-boot-brain/drivers/mux/mux-uclass.c
Simon Glass 41575d8e4c dm: treewide: Rename auto_alloc_size members to be shorter
This construct is quite long-winded. In earlier days it made some sense
since auto-allocation was a strange concept. But with driver model now
used pretty universally, we can shorten this to 'auto'. This reduces
verbosity and makes it easier to read.

Coincidentally it also ensures that every declaration is on one line,
thus making dtoc's job easier.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-12-13 08:00:25 -07:00

336 lines
7.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Multiplexer subsystem
*
* Based on the linux multiplexer framework
*
* Copyright (C) 2017 Axentia Technologies AB
* Author: Peter Rosin <peda@axentia.se>
*
* Copyright (C) 2017-2018 Texas Instruments Incorporated - http://www.ti.com/
* Jean-Jacques Hiblot <jjhiblot@ti.com>
*/
#include <common.h>
#include <dm.h>
#include <mux-internal.h>
#include <dm/device-internal.h>
#include <dm/device_compat.h>
#include <dm/devres.h>
#include <dt-bindings/mux/mux.h>
#include <linux/bug.h>
/*
* The idle-as-is "state" is not an actual state that may be selected, it
* only implies that the state should not be changed. So, use that state
* as indication that the cached state of the multiplexer is unknown.
*/
#define MUX_CACHE_UNKNOWN MUX_IDLE_AS_IS
/**
* mux_control_ops() - Get the mux_control ops.
* @dev: The client device.
*
* Return: A pointer to the 'mux_control_ops' of the device.
*/
static inline const struct mux_control_ops *mux_dev_ops(struct udevice *dev)
{
return (const struct mux_control_ops *)dev->driver->ops;
}
/**
* mux_control_set() - Set the state of the given mux controller.
* @mux: A multiplexer control
* @state: The new requested state.
*
* Return: 0 if OK, or a negative error code.
*/
static int mux_control_set(struct mux_control *mux, int state)
{
int ret = mux_dev_ops(mux->dev)->set(mux, state);
mux->cached_state = ret < 0 ? MUX_CACHE_UNKNOWN : state;
return ret;
}
unsigned int mux_control_states(struct mux_control *mux)
{
return mux->states;
}
/**
* __mux_control_select() - Select the given multiplexer state.
* @mux: The mux-control to request a change of state from.
* @state: The new requested state.
*
* Try to set the mux to the requested state. If not, try to revert if
* appropriate.
*/
static int __mux_control_select(struct mux_control *mux, int state)
{
int ret;
if (WARN_ON(state < 0 || state >= mux->states))
return -EINVAL;
if (mux->cached_state == state)
return 0;
ret = mux_control_set(mux, state);
if (ret >= 0)
return 0;
/* The mux update failed, try to revert if appropriate... */
if (mux->idle_state != MUX_IDLE_AS_IS)
mux_control_set(mux, mux->idle_state);
return ret;
}
int mux_control_select(struct mux_control *mux, unsigned int state)
{
int ret;
if (mux->in_use)
return -EBUSY;
ret = __mux_control_select(mux, state);
if (ret < 0)
return ret;
mux->in_use = true;
return 0;
}
int mux_control_deselect(struct mux_control *mux)
{
int ret = 0;
if (mux->idle_state != MUX_IDLE_AS_IS &&
mux->idle_state != mux->cached_state)
ret = mux_control_set(mux, mux->idle_state);
mux->in_use = false;
return ret;
}
static int mux_of_xlate_default(struct mux_chip *mux_chip,
struct ofnode_phandle_args *args,
struct mux_control **muxp)
{
struct mux_control *mux;
int id;
log_debug("%s(muxp=%p)\n", __func__, muxp);
if (args->args_count > 1) {
debug("Invaild args_count: %d\n", args->args_count);
return -EINVAL;
}
if (args->args_count)
id = args->args[0];
else
id = 0;
if (id >= mux_chip->controllers) {
pr_err("bad mux controller %u specified in %s\n",
id, ofnode_get_name(args->node));
return -ERANGE;
}
mux = &mux_chip->mux[id];
mux->id = id;
*muxp = mux;
return 0;
}
/**
* mux_get_by_indexed_prop() - Get a mux control by integer index
* @dev: The client device.
* @prop_name: Name of the device tree property.
* @index: The index of the mux to get
* @mux: A pointer to the 'mux_control' struct to initialize.
*
* Return: 0 of OK, -errno otherwise.
*/
static int mux_get_by_indexed_prop(struct udevice *dev, const char *prop_name,
int index, struct mux_control **mux)
{
int ret;
struct ofnode_phandle_args args;
struct udevice *dev_mux;
const struct mux_control_ops *ops;
struct mux_chip *mux_chip;
log_debug("%s(dev=%p, index=%d, mux=%p)\n", __func__, dev, index, mux);
ret = dev_read_phandle_with_args(dev, prop_name, "#mux-control-cells",
0, index, &args);
if (ret) {
debug("%s: fdtdec_parse_phandle_with_args failed: err=%d\n",
__func__, ret);
return ret;
}
ret = uclass_get_device_by_ofnode(UCLASS_MUX, args.node, &dev_mux);
if (ret) {
debug("%s: uclass_get_device_by_ofnode failed: err=%d\n",
__func__, ret);
return ret;
}
mux_chip = dev_get_uclass_priv(dev_mux);
ops = mux_dev_ops(dev_mux);
if (ops->of_xlate)
ret = ops->of_xlate(mux_chip, &args, mux);
else
ret = mux_of_xlate_default(mux_chip, &args, mux);
if (ret) {
debug("of_xlate() failed: %d\n", ret);
return ret;
}
(*mux)->dev = dev_mux;
return 0;
}
int mux_get_by_index(struct udevice *dev, int index, struct mux_control **mux)
{
return mux_get_by_indexed_prop(dev, "mux-controls", index, mux);
}
int mux_control_get(struct udevice *dev, const char *name,
struct mux_control **mux)
{
int index;
debug("%s(dev=%p, name=%s, mux=%p)\n", __func__, dev, name, mux);
index = dev_read_stringlist_search(dev, "mux-control-names", name);
if (index < 0) {
debug("fdt_stringlist_search() failed: %d\n", index);
return index;
}
return mux_get_by_index(dev, index, mux);
}
void mux_control_put(struct mux_control *mux)
{
mux_control_deselect(mux);
}
/**
* devm_mux_control_release() - Release the given managed mux.
* @dev: The client device.
* @res: Pointer to the mux to be released.
*
* This function is called by devres to release the mux. It reverses the
* effects of mux_control_get().
*/
static void devm_mux_control_release(struct udevice *dev, void *res)
{
mux_control_put(*(struct mux_control **)res);
}
struct mux_control *devm_mux_control_get(struct udevice *dev, const char *id)
{
int rc;
struct mux_control **mux;
mux = devres_alloc(devm_mux_control_release,
sizeof(struct mux_control *), __GFP_ZERO);
if (unlikely(!mux))
return ERR_PTR(-ENOMEM);
rc = mux_control_get(dev, id, mux);
if (rc)
return ERR_PTR(rc);
devres_add(dev, mux);
return *mux;
}
int mux_alloc_controllers(struct udevice *dev, unsigned int controllers)
{
int i;
struct mux_chip *mux_chip = dev_get_uclass_priv(dev);
mux_chip->mux = devm_kmalloc(dev,
sizeof(struct mux_control) * controllers,
__GFP_ZERO);
if (!mux_chip->mux)
return -ENOMEM;
mux_chip->controllers = controllers;
for (i = 0; i < mux_chip->controllers; ++i) {
struct mux_control *mux = &mux_chip->mux[i];
mux->dev = dev;
mux->cached_state = MUX_CACHE_UNKNOWN;
mux->idle_state = MUX_IDLE_AS_IS;
mux->in_use = false;
mux->id = i;
}
return 0;
}
static int mux_uclass_post_probe(struct udevice *dev)
{
int i, ret;
struct mux_chip *mux_chip = dev_get_uclass_priv(dev);
/* Set all mux controllers to their idle state. */
for (i = 0; i < mux_chip->controllers; ++i) {
struct mux_control *mux = &mux_chip->mux[i];
if (mux->idle_state == mux->cached_state)
continue;
ret = mux_control_set(mux, mux->idle_state);
if (ret < 0) {
dev_err(dev, "unable to set idle state\n");
return ret;
}
}
return 0;
}
int dm_mux_init(void)
{
struct uclass *uc;
struct udevice *dev;
int ret;
ret = uclass_get(UCLASS_MUX, &uc);
if (ret < 0) {
log_debug("unable to get MUX uclass\n");
return ret;
}
uclass_foreach_dev(dev, uc) {
if (dev_read_bool(dev, "u-boot,mux-autoprobe")) {
ret = device_probe(dev);
if (ret)
log_debug("unable to probe device %s\n",
dev->name);
}
}
return 0;
}
UCLASS_DRIVER(mux) = {
.id = UCLASS_MUX,
.name = "mux",
.post_probe = mux_uclass_post_probe,
.per_device_auto = sizeof(struct mux_chip),
};