diff options
| author | Yuval Adam <_@yuv.al> | 2017-08-30 08:25:59 +0000 |
|---|---|---|
| committer | Yuval Adam <_@yuv.al> | 2017-08-30 08:25:59 +0000 |
| commit | 8e4bff4cab0ddac6060645b0715210484d02ff40 (patch) | |
| tree | 3a5c3024371a04692a3a6d9974d001cdff8ebf84 /drivers/mailbox | |
Diffstat (limited to 'drivers/mailbox')
| -rw-r--r-- | drivers/mailbox/Kconfig | 19 | ||||
| -rw-r--r-- | drivers/mailbox/Makefile | 5 | ||||
| -rw-r--r-- | drivers/mailbox/mailbox.c | 465 | ||||
| -rw-r--r-- | drivers/mailbox/pl320-ipc.c | 198 |
4 files changed, 687 insertions, 0 deletions
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig new file mode 100644 index 00000000..9545c9f0 --- /dev/null +++ b/drivers/mailbox/Kconfig @@ -0,0 +1,19 @@ +menuconfig MAILBOX + bool "Mailbox Hardware Support" + help + Mailbox is a framework to control hardware communication between + on-chip processors through queued messages and interrupt driven + signals. Say Y if your platform supports hardware mailboxes. + +if MAILBOX +config PL320_MBOX + bool "ARM PL320 Mailbox" + depends on ARM_AMBA + help + An implementation of the ARM PL320 Interprocessor Communication + Mailbox (IPCM), tailored for the Calxeda Highbank. It is used to + send short messages between Highbank's A9 cores and the EnergyCore + Management Engine, primarily for cpufreq. Say Y here if you want + to use the PL320 IPCM support. + +endif diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile new file mode 100644 index 00000000..fefef7eb --- /dev/null +++ b/drivers/mailbox/Makefile @@ -0,0 +1,5 @@ +# Generic MAILBOX API + +obj-$(CONFIG_MAILBOX) += mailbox.o + +obj-$(CONFIG_PL320_MBOX) += pl320-ipc.o diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c new file mode 100644 index 00000000..afcb4305 --- /dev/null +++ b/drivers/mailbox/mailbox.c @@ -0,0 +1,465 @@ +/* + * 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); diff --git a/drivers/mailbox/pl320-ipc.c b/drivers/mailbox/pl320-ipc.c new file mode 100644 index 00000000..f3755e0a --- /dev/null +++ b/drivers/mailbox/pl320-ipc.c @@ -0,0 +1,198 @@ +/* + * Copyright 2012 Calxeda, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ +#include <linux/types.h> +#include <linux/err.h> +#include <linux/delay.h> +#include <linux/export.h> +#include <linux/io.h> +#include <linux/interrupt.h> +#include <linux/completion.h> +#include <linux/mutex.h> +#include <linux/notifier.h> +#include <linux/spinlock.h> +#include <linux/device.h> +#include <linux/amba/bus.h> + +#include <linux/pl320-ipc.h> + +#define IPCMxSOURCE(m) ((m) * 0x40) +#define IPCMxDSET(m) (((m) * 0x40) + 0x004) +#define IPCMxDCLEAR(m) (((m) * 0x40) + 0x008) +#define IPCMxDSTATUS(m) (((m) * 0x40) + 0x00C) +#define IPCMxMODE(m) (((m) * 0x40) + 0x010) +#define IPCMxMSET(m) (((m) * 0x40) + 0x014) +#define IPCMxMCLEAR(m) (((m) * 0x40) + 0x018) +#define IPCMxMSTATUS(m) (((m) * 0x40) + 0x01C) +#define IPCMxSEND(m) (((m) * 0x40) + 0x020) +#define IPCMxDR(m, dr) (((m) * 0x40) + ((dr) * 4) + 0x024) + +#define IPCMMIS(irq) (((irq) * 8) + 0x800) +#define IPCMRIS(irq) (((irq) * 8) + 0x804) + +#define MBOX_MASK(n) (1 << (n)) +#define IPC_TX_MBOX 1 +#define IPC_RX_MBOX 2 + +#define CHAN_MASK(n) (1 << (n)) +#define A9_SOURCE 1 +#define M3_SOURCE 0 + +static void __iomem *ipc_base; +static int ipc_irq; +static DEFINE_MUTEX(ipc_m1_lock); +static DECLARE_COMPLETION(ipc_completion); +static ATOMIC_NOTIFIER_HEAD(ipc_notifier); + +static inline void set_destination(int source, int mbox) +{ + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxDSET(mbox)); + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxMSET(mbox)); +} + +static inline void clear_destination(int source, int mbox) +{ + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxDCLEAR(mbox)); + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxMCLEAR(mbox)); +} + +static void __ipc_send(int mbox, u32 *data) +{ + int i; + for (i = 0; i < 7; i++) + __raw_writel(data[i], ipc_base + IPCMxDR(mbox, i)); + __raw_writel(0x1, ipc_base + IPCMxSEND(mbox)); +} + +static u32 __ipc_rcv(int mbox, u32 *data) +{ + int i; + for (i = 0; i < 7; i++) + data[i] = __raw_readl(ipc_base + IPCMxDR(mbox, i)); + return data[1]; +} + +/* blocking implmentation from the A9 side, not usuable in interrupts! */ +int pl320_ipc_transmit(u32 *data) +{ + int ret; + + mutex_lock(&ipc_m1_lock); + + init_completion(&ipc_completion); + __ipc_send(IPC_TX_MBOX, data); + ret = wait_for_completion_timeout(&ipc_completion, + msecs_to_jiffies(1000)); + if (ret == 0) { + ret = -ETIMEDOUT; + goto out; + } + + ret = __ipc_rcv(IPC_TX_MBOX, data); +out: + mutex_unlock(&ipc_m1_lock); + return ret; +} +EXPORT_SYMBOL_GPL(pl320_ipc_transmit); + +static irqreturn_t ipc_handler(int irq, void *dev) +{ + u32 irq_stat; + u32 data[7]; + + irq_stat = __raw_readl(ipc_base + IPCMMIS(1)); + if (irq_stat & MBOX_MASK(IPC_TX_MBOX)) { + __raw_writel(0, ipc_base + IPCMxSEND(IPC_TX_MBOX)); + complete(&ipc_completion); + } + if (irq_stat & MBOX_MASK(IPC_RX_MBOX)) { + __ipc_rcv(IPC_RX_MBOX, data); + atomic_notifier_call_chain(&ipc_notifier, data[0], data + 1); + __raw_writel(2, ipc_base + IPCMxSEND(IPC_RX_MBOX)); + } + + return IRQ_HANDLED; +} + +int pl320_ipc_register_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_register(&ipc_notifier, nb); +} +EXPORT_SYMBOL_GPL(pl320_ipc_register_notifier); + +int pl320_ipc_unregister_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_unregister(&ipc_notifier, nb); +} +EXPORT_SYMBOL_GPL(pl320_ipc_unregister_notifier); + +static int pl320_probe(struct amba_device *adev, const struct amba_id *id) +{ + int ret; + + ipc_base = ioremap(adev->res.start, resource_size(&adev->res)); + if (ipc_base == NULL) + return -ENOMEM; + + __raw_writel(0, ipc_base + IPCMxSEND(IPC_TX_MBOX)); + + ipc_irq = adev->irq[0]; + ret = request_irq(ipc_irq, ipc_handler, 0, dev_name(&adev->dev), NULL); + if (ret < 0) + goto err; + + /* Init slow mailbox */ + __raw_writel(CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxSOURCE(IPC_TX_MBOX)); + __raw_writel(CHAN_MASK(M3_SOURCE), + ipc_base + IPCMxDSET(IPC_TX_MBOX)); + __raw_writel(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxMSET(IPC_TX_MBOX)); + + /* Init receive mailbox */ + __raw_writel(CHAN_MASK(M3_SOURCE), + ipc_base + IPCMxSOURCE(IPC_RX_MBOX)); + __raw_writel(CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxDSET(IPC_RX_MBOX)); + __raw_writel(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE), + ipc_base + IPCMxMSET(IPC_RX_MBOX)); + + return 0; +err: + iounmap(ipc_base); + return ret; +} + +static struct amba_id pl320_ids[] = { + { + .id = 0x00041320, + .mask = 0x000fffff, + }, + { 0, 0 }, +}; + +static struct amba_driver pl320_driver = { + .drv = { + .name = "pl320", + }, + .id_table = pl320_ids, + .probe = pl320_probe, +}; + +static int __init ipc_init(void) +{ + return amba_driver_register(&pl320_driver); +} +module_init(ipc_init); |
