+++ /dev/null
-/*
- * Mailbox: Common code for Mailbox controllers and users
- *
- * Copyright (C) 2013-2014 Linaro Ltd.
- * Author: Jassi Brar <jassisinghbrar@gmail.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/interrupt.h>
-#include <linux/spinlock.h>
-#include <linux/mutex.h>
-#include <linux/delay.h>
-#include <linux/slab.h>
-#include <linux/err.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/bitops.h>
-#include <linux/mailbox_client.h>
-#include <linux/mailbox_controller.h>
-
-#define TXDONE_BY_IRQ BIT(0) /* controller has remote RTR irq */
-#define TXDONE_BY_POLL BIT(1) /* controller can read status of last TX */
-#define TXDONE_BY_ACK BIT(2) /* S/W ACK recevied by Client ticks the TX */
-
-static LIST_HEAD(mbox_cons);
-static DEFINE_MUTEX(con_mutex);
-
-static int add_to_rbuf(struct mbox_chan *chan, void *mssg)
-{
- int idx;
- unsigned long flags;
-
- spin_lock_irqsave(&chan->lock, flags);
-
- /* See if there is any space left */
- if (chan->msg_count == MBOX_TX_QUEUE_LEN) {
- spin_unlock_irqrestore(&chan->lock, flags);
- return -ENOBUFS;
- }
-
- idx = chan->msg_free;
- chan->msg_data[idx] = mssg;
- chan->msg_count++;
-
- if (idx == MBOX_TX_QUEUE_LEN - 1)
- chan->msg_free = 0;
- else
- chan->msg_free++;
-
- spin_unlock_irqrestore(&chan->lock, flags);
-
- return idx;
-}
-
-static void msg_submit(struct mbox_chan *chan)
-{
- unsigned count, idx;
- unsigned long flags;
- void *data;
- int err;
-
- spin_lock_irqsave(&chan->lock, flags);
-
- if (!chan->msg_count || chan->active_req)
- goto exit;
-
- count = chan->msg_count;
- idx = chan->msg_free;
- if (idx >= count)
- idx -= count;
- else
- idx += MBOX_TX_QUEUE_LEN - count;
-
- data = chan->msg_data[idx];
-
- /* Try to submit a message to the MBOX controller */
- err = chan->mbox->ops->send_data(chan, data);
- if (!err) {
- chan->active_req = data;
- chan->msg_count--;
- }
-exit:
- spin_unlock_irqrestore(&chan->lock, flags);
-}
-
-static void tx_tick(struct mbox_chan *chan, int r)
-{
- unsigned long flags;
- void *mssg;
-
- spin_lock_irqsave(&chan->lock, flags);
- mssg = chan->active_req;
- chan->active_req = NULL;
- spin_unlock_irqrestore(&chan->lock, flags);
-
- /* Submit next message */
- msg_submit(chan);
-
- /* Notify the client */
- if (mssg && chan->cl->tx_done)
- chan->cl->tx_done(chan->cl, mssg, r);
-
- if (chan->cl->tx_block)
- complete(&chan->tx_complete);
-}
-
-static void poll_txdone(unsigned long data)
-{
- struct mbox_controller *mbox = (struct mbox_controller *)data;
- bool txdone, resched = false;
- int i;
-
- for (i = 0; i < mbox->num_chans; i++) {
- struct mbox_chan *chan = &mbox->chans[i];
-
- if (chan->active_req && chan->cl) {
- resched = true;
- txdone = chan->mbox->ops->last_tx_done(chan);
- if (txdone)
- tx_tick(chan, 0);
- }
- }
-
- if (resched)
- mod_timer(&mbox->poll, jiffies +
- msecs_to_jiffies(mbox->txpoll_period));
-}
-
-/**
- * mbox_chan_received_data - A way for controller driver to push data
- * received from remote to the upper layer.
- * @chan: Pointer to the mailbox channel on which RX happened.
- * @mssg: Client specific message typecasted as void *
- *
- * After startup and before shutdown any data received on the chan
- * is passed on to the API via atomic mbox_chan_received_data().
- * The controller should ACK the RX only after this call returns.
- */
-void mbox_chan_received_data(struct mbox_chan *chan, void *mssg)
-{
- /* No buffering the received data */
- if (chan->cl->rx_callback)
- chan->cl->rx_callback(chan->cl, mssg);
-}
-EXPORT_SYMBOL_GPL(mbox_chan_received_data);
-
-/**
- * mbox_chan_txdone - A way for controller driver to notify the
- * framework that the last TX has completed.
- * @chan: Pointer to the mailbox chan on which TX happened.
- * @r: Status of last TX - OK or ERROR
- *
- * The controller that has IRQ for TX ACK calls this atomic API
- * to tick the TX state machine. It works only if txdone_irq
- * is set by the controller.
- */
-void mbox_chan_txdone(struct mbox_chan *chan, int r)
-{
- if (unlikely(!(chan->txdone_method & TXDONE_BY_IRQ))) {
- dev_err(chan->mbox->dev,
- "Controller can't run the TX ticker\n");
- return;
- }
-
- tx_tick(chan, r);
-}
-EXPORT_SYMBOL_GPL(mbox_chan_txdone);
-
-/**
- * mbox_client_txdone - The way for a client to run the TX state machine.
- * @chan: Mailbox channel assigned to this client.
- * @r: Success status of last transmission.
- *
- * The client/protocol had received some 'ACK' packet and it notifies
- * the API that the last packet was sent successfully. This only works
- * if the controller can't sense TX-Done.
- */
-void mbox_client_txdone(struct mbox_chan *chan, int r)
-{
- if (unlikely(!(chan->txdone_method & TXDONE_BY_ACK))) {
- dev_err(chan->mbox->dev, "Client can't run the TX ticker\n");
- return;
- }
-
- tx_tick(chan, r);
-}
-EXPORT_SYMBOL_GPL(mbox_client_txdone);
-
-/**
- * mbox_client_peek_data - A way for client driver to pull data
- * received from remote by the controller.
- * @chan: Mailbox channel assigned to this client.
- *
- * A poke to controller driver for any received data.
- * The data is actually passed onto client via the
- * mbox_chan_received_data()
- * The call can be made from atomic context, so the controller's
- * implementation of peek_data() must not sleep.
- *
- * Return: True, if controller has, and is going to push after this,
- * some data.
- * False, if controller doesn't have any data to be read.
- */
-bool mbox_client_peek_data(struct mbox_chan *chan)
-{
- if (chan->mbox->ops->peek_data)
- return chan->mbox->ops->peek_data(chan);
-
- return false;
-}
-EXPORT_SYMBOL_GPL(mbox_client_peek_data);
-
-/**
- * mbox_send_message - For client to submit a message to be
- * sent to the remote.
- * @chan: Mailbox channel assigned to this client.
- * @mssg: Client specific message typecasted.
- *
- * For client to submit data to the controller destined for a remote
- * processor. If the client had set 'tx_block', the call will return
- * either when the remote receives the data or when 'tx_tout' millisecs
- * run out.
- * In non-blocking mode, the requests are buffered by the API and a
- * non-negative token is returned for each queued request. If the request
- * is not queued, a negative token is returned. Upon failure or successful
- * TX, the API calls 'tx_done' from atomic context, from which the client
- * could submit yet another request.
- * The pointer to message should be preserved until it is sent
- * over the chan, i.e, tx_done() is made.
- * This function could be called from atomic context as it simply
- * queues the data and returns a token against the request.
- *
- * Return: Non-negative integer for successful submission (non-blocking mode)
- * or transmission over chan (blocking mode).
- * Negative value denotes failure.
- */
-int mbox_send_message(struct mbox_chan *chan, void *mssg)
-{
- int t;
-
- if (!chan || !chan->cl)
- return -EINVAL;
-
- t = add_to_rbuf(chan, mssg);
- if (t < 0) {
- dev_err(chan->mbox->dev, "Try increasing MBOX_TX_QUEUE_LEN\n");
- return t;
- }
-
- msg_submit(chan);
-
- if (chan->txdone_method == TXDONE_BY_POLL)
- poll_txdone((unsigned long)chan->mbox);
-
- if (chan->cl->tx_block && chan->active_req) {
- unsigned long wait;
- int ret;
-
- if (!chan->cl->tx_tout) /* wait forever */
- wait = msecs_to_jiffies(3600000);
- else
- wait = msecs_to_jiffies(chan->cl->tx_tout);
-
- ret = wait_for_completion_timeout(&chan->tx_complete, wait);
- if (ret == 0) {
- t = -EIO;
- tx_tick(chan, -EIO);
- }
- }
-
- return t;
-}
-EXPORT_SYMBOL_GPL(mbox_send_message);
-
-/**
- * mbox_request_channel - Request a mailbox channel.
- * @cl: Identity of the client requesting the channel.
- * @index: Index of mailbox specifier in 'mboxes' property.
- *
- * The Client specifies its requirements and capabilities while asking for
- * a mailbox channel. It can't be called from atomic context.
- * The channel is exclusively allocated and can't be used by another
- * client before the owner calls mbox_free_channel.
- * After assignment, any packet received on this channel will be
- * handed over to the client via the 'rx_callback'.
- * The framework holds reference to the client, so the mbox_client
- * structure shouldn't be modified until the mbox_free_channel returns.
- *
- * Return: Pointer to the channel assigned to the client if successful.
- * ERR_PTR for request failure.
- */
-struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
-{
- struct device *dev = cl->dev;
- struct mbox_controller *mbox;
- struct of_phandle_args spec;
- struct mbox_chan *chan;
- unsigned long flags;
- int ret;
-
- if (!dev || !dev->of_node) {
- pr_debug("%s: No owner device node\n", __func__);
- return ERR_PTR(-ENODEV);
- }
-
- mutex_lock(&con_mutex);
-
- if (of_parse_phandle_with_args(dev->of_node, "mboxes",
- "#mbox-cells", index, &spec)) {
- dev_dbg(dev, "%s: can't parse \"mboxes\" property\n", __func__);
- mutex_unlock(&con_mutex);
- return ERR_PTR(-ENODEV);
- }
-
- chan = NULL;
- list_for_each_entry(mbox, &mbox_cons, node)
- if (mbox->dev->of_node == spec.np) {
- chan = mbox->of_xlate(mbox, &spec);
- break;
- }
-
- of_node_put(spec.np);
-
- if (!chan || chan->cl || !try_module_get(mbox->dev->driver->owner)) {
- dev_dbg(dev, "%s: mailbox not free\n", __func__);
- mutex_unlock(&con_mutex);
- return ERR_PTR(-EBUSY);
- }
-
- spin_lock_irqsave(&chan->lock, flags);
- chan->msg_free = 0;
- chan->msg_count = 0;
- chan->active_req = NULL;
- chan->cl = cl;
- init_completion(&chan->tx_complete);
-
- if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
- chan->txdone_method |= TXDONE_BY_ACK;
-
- spin_unlock_irqrestore(&chan->lock, flags);
-
- ret = chan->mbox->ops->startup(chan);
- if (ret) {
- dev_err(dev, "Unable to startup the chan (%d)\n", ret);
- mbox_free_channel(chan);
- chan = ERR_PTR(ret);
- }
-
- mutex_unlock(&con_mutex);
- return chan;
-}
-EXPORT_SYMBOL_GPL(mbox_request_channel);
-
-/**
- * mbox_free_channel - The client relinquishes control of a mailbox
- * channel by this call.
- * @chan: The mailbox channel to be freed.
- */
-void mbox_free_channel(struct mbox_chan *chan)
-{
- unsigned long flags;
-
- if (!chan || !chan->cl)
- return;
-
- chan->mbox->ops->shutdown(chan);
-
- /* The queued TX requests are simply aborted, no callbacks are made */
- spin_lock_irqsave(&chan->lock, flags);
- chan->cl = NULL;
- chan->active_req = NULL;
- if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK))
- chan->txdone_method = TXDONE_BY_POLL;
-
- module_put(chan->mbox->dev->driver->owner);
- spin_unlock_irqrestore(&chan->lock, flags);
-}
-EXPORT_SYMBOL_GPL(mbox_free_channel);
-
-static struct mbox_chan *
-of_mbox_index_xlate(struct mbox_controller *mbox,
- const struct of_phandle_args *sp)
-{
- int ind = sp->args[0];
-
- if (ind >= mbox->num_chans)
- return NULL;
-
- return &mbox->chans[ind];
-}
-
-/**
- * mbox_controller_register - Register the mailbox controller
- * @mbox: Pointer to the mailbox controller.
- *
- * The controller driver registers its communication channels
- */
-int mbox_controller_register(struct mbox_controller *mbox)
-{
- int i, txdone;
-
- /* Sanity check */
- if (!mbox || !mbox->dev || !mbox->ops || !mbox->num_chans)
- return -EINVAL;
-
- if (mbox->txdone_irq)
- txdone = TXDONE_BY_IRQ;
- else if (mbox->txdone_poll)
- txdone = TXDONE_BY_POLL;
- else /* It has to be ACK then */
- txdone = TXDONE_BY_ACK;
-
- if (txdone == TXDONE_BY_POLL) {
- mbox->poll.function = &poll_txdone;
- mbox->poll.data = (unsigned long)mbox;
- init_timer(&mbox->poll);
- }
-
- for (i = 0; i < mbox->num_chans; i++) {
- struct mbox_chan *chan = &mbox->chans[i];
-
- chan->cl = NULL;
- chan->mbox = mbox;
- chan->txdone_method = txdone;
- spin_lock_init(&chan->lock);
- }
-
- if (!mbox->of_xlate)
- mbox->of_xlate = of_mbox_index_xlate;
-
- mutex_lock(&con_mutex);
- list_add_tail(&mbox->node, &mbox_cons);
- mutex_unlock(&con_mutex);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(mbox_controller_register);
-
-/**
- * mbox_controller_unregister - Unregister the mailbox controller
- * @mbox: Pointer to the mailbox controller.
- */
-void mbox_controller_unregister(struct mbox_controller *mbox)
-{
- int i;
-
- if (!mbox)
- return;
-
- mutex_lock(&con_mutex);
-
- list_del(&mbox->node);
-
- for (i = 0; i < mbox->num_chans; i++)
- mbox_free_channel(&mbox->chans[i]);
-
- if (mbox->txdone_poll)
- del_timer_sync(&mbox->poll);
-
- mutex_unlock(&con_mutex);
-}
-EXPORT_SYMBOL_GPL(mbox_controller_unregister);
projects / firefly-linux-kernel-4.4.55.git / blobdiff