mailbox: Add support for ST's Mailbox IP
ST's platforms currently support a maximum of 5 Mailboxes, one for each of the supported co-processors situated on the platform. Each Mailbox is divided up into 4 instances which consist of 32 channels. Messages are passed between the application and co-processors using shared memory areas. It is the Client's responsibility to manage these areas. Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
This commit is contained in:
Lee Jones
Jassi Brar
parent
b5f6737685
commit
9ef4546cbd
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@ -71,4 +71,11 @@ config BCM2835_MBOX
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the services of the Videocore. Say Y here if you want to use the
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BCM2835 Mailbox.
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config STI_MBOX
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tristate "STI Mailbox framework support"
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depends on ARCH_STI && OF
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help
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Mailbox implementation for STMicroelectonics family chips with
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hardware for interprocessor communication.
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endif
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@ -13,3 +13,5 @@ obj-$(CONFIG_PCC) += pcc.o
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obj-$(CONFIG_ALTERA_MBOX) += mailbox-altera.o
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obj-$(CONFIG_BCM2835_MBOX) += bcm2835-mailbox.o
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obj-$(CONFIG_STI_MBOX) += mailbox-sti.o
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@ -0,0 +1,513 @@
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/*
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* STi Mailbox
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*
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* Copyright (C) 2015 ST Microelectronics
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*
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* Author: Lee Jones <lee.jones@linaro.org> for ST Microelectronics
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*
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* Based on the original driver written by;
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* Alexandre Torgue, Olivier Lebreton and Loic Pallardy
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/err.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/mailbox_controller.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include "mailbox.h"
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#define STI_MBOX_INST_MAX 4 /* RAM saving: Max supported instances */
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#define STI_MBOX_CHAN_MAX 20 /* RAM saving: Max supported channels */
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#define STI_IRQ_VAL_OFFSET 0x04 /* Read interrupt status */
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#define STI_IRQ_SET_OFFSET 0x24 /* Generate a Tx channel interrupt */
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#define STI_IRQ_CLR_OFFSET 0x44 /* Clear pending Rx interrupts */
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#define STI_ENA_VAL_OFFSET 0x64 /* Read enable status */
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#define STI_ENA_SET_OFFSET 0x84 /* Enable a channel */
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#define STI_ENA_CLR_OFFSET 0xa4 /* Disable a channel */
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#define MBOX_BASE(mdev, inst) ((mdev)->base + ((inst) * 4))
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/**
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* STi Mailbox device data
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*
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* An IP Mailbox is currently composed of 4 instances
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* Each instance is currently composed of 32 channels
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* This means that we have 128 channels per Mailbox
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* A channel an be used for TX or RX
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*
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* @dev: Device to which it is attached
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* @mbox: Representation of a communication channel controller
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* @base: Base address of the register mapping region
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* @name: Name of the mailbox
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* @enabled: Local copy of enabled channels
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* @lock: Mutex protecting enabled status
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*/
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struct sti_mbox_device {
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struct device *dev;
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struct mbox_controller *mbox;
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void __iomem *base;
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const char *name;
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u32 enabled[STI_MBOX_INST_MAX];
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spinlock_t lock;
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};
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/**
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* STi Mailbox platform specfic configuration
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*
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* @num_inst: Maximum number of instances in one HW Mailbox
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* @num_chan: Maximum number of channel per instance
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*/
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struct sti_mbox_pdata {
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unsigned int num_inst;
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unsigned int num_chan;
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};
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/**
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* STi Mailbox allocated channel information
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*
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* @mdev: Pointer to parent Mailbox device
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* @instance: Instance number channel resides in
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* @channel: Channel number pertaining to this container
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*/
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struct sti_channel {
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struct sti_mbox_device *mdev;
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unsigned int instance;
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unsigned int channel;
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};
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static inline bool sti_mbox_channel_is_enabled(struct mbox_chan *chan)
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{
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struct sti_channel *chan_info = chan->con_priv;
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struct sti_mbox_device *mdev = chan_info->mdev;
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unsigned int instance = chan_info->instance;
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unsigned int channel = chan_info->channel;
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return mdev->enabled[instance] & BIT(channel);
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}
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static inline
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struct mbox_chan *sti_mbox_to_channel(struct mbox_controller *mbox,
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unsigned int instance,
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unsigned int channel)
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{
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struct sti_channel *chan_info;
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int i;
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for (i = 0; i < mbox->num_chans; i++) {
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chan_info = mbox->chans[i].con_priv;
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if (chan_info &&
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chan_info->instance == instance &&
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chan_info->channel == channel)
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return &mbox->chans[i];
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}
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dev_err(mbox->dev,
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"Channel not registered: instance: %d channel: %d\n",
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instance, channel);
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return NULL;
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}
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static void sti_mbox_enable_channel(struct mbox_chan *chan)
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{
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struct sti_channel *chan_info = chan->con_priv;
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struct sti_mbox_device *mdev = chan_info->mdev;
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unsigned int instance = chan_info->instance;
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unsigned int channel = chan_info->channel;
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unsigned long flags;
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void __iomem *base = MBOX_BASE(mdev, instance);
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spin_lock_irqsave(&mdev->lock, flags);
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mdev->enabled[instance] |= BIT(channel);
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writel_relaxed(BIT(channel), base + STI_ENA_SET_OFFSET);
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spin_unlock_irqrestore(&mdev->lock, flags);
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}
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static void sti_mbox_disable_channel(struct mbox_chan *chan)
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{
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struct sti_channel *chan_info = chan->con_priv;
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struct sti_mbox_device *mdev = chan_info->mdev;
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unsigned int instance = chan_info->instance;
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unsigned int channel = chan_info->channel;
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unsigned long flags;
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void __iomem *base = MBOX_BASE(mdev, instance);
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spin_lock_irqsave(&mdev->lock, flags);
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mdev->enabled[instance] &= ~BIT(channel);
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writel_relaxed(BIT(channel), base + STI_ENA_CLR_OFFSET);
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spin_unlock_irqrestore(&mdev->lock, flags);
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}
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static void sti_mbox_clear_irq(struct mbox_chan *chan)
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{
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struct sti_channel *chan_info = chan->con_priv;
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struct sti_mbox_device *mdev = chan_info->mdev;
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unsigned int instance = chan_info->instance;
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unsigned int channel = chan_info->channel;
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void __iomem *base = MBOX_BASE(mdev, instance);
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writel_relaxed(BIT(channel), base + STI_IRQ_CLR_OFFSET);
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}
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static struct mbox_chan *sti_mbox_irq_to_channel(struct sti_mbox_device *mdev,
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unsigned int instance)
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{
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struct mbox_controller *mbox = mdev->mbox;
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struct mbox_chan *chan = NULL;
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unsigned int channel;
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unsigned long bits;
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void __iomem *base = MBOX_BASE(mdev, instance);
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bits = readl_relaxed(base + STI_IRQ_VAL_OFFSET);
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if (!bits)
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/* No IRQs fired in specified instance */
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return NULL;
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/* An IRQ has fired, find the associated channel */
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for (channel = 0; bits; channel++) {
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if (!test_and_clear_bit(channel, &bits))
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continue;
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chan = sti_mbox_to_channel(mbox, instance, channel);
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if (chan) {
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dev_dbg(mbox->dev,
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"IRQ fired on instance: %d channel: %d\n",
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instance, channel);
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break;
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}
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}
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return chan;
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}
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static irqreturn_t sti_mbox_thread_handler(int irq, void *data)
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{
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struct sti_mbox_device *mdev = data;
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struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
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struct mbox_chan *chan;
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unsigned int instance;
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for (instance = 0; instance < pdata->num_inst; instance++) {
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keep_looking:
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chan = sti_mbox_irq_to_channel(mdev, instance);
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if (!chan)
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continue;
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mbox_chan_received_data(chan, NULL);
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sti_mbox_clear_irq(chan);
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sti_mbox_enable_channel(chan);
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goto keep_looking;
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}
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return IRQ_HANDLED;
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}
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static irqreturn_t sti_mbox_irq_handler(int irq, void *data)
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{
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struct sti_mbox_device *mdev = data;
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struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
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struct sti_channel *chan_info;
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struct mbox_chan *chan;
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unsigned int instance;
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int ret = IRQ_NONE;
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for (instance = 0; instance < pdata->num_inst; instance++) {
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chan = sti_mbox_irq_to_channel(mdev, instance);
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if (!chan)
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continue;
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chan_info = chan->con_priv;
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if (!sti_mbox_channel_is_enabled(chan)) {
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dev_warn(mdev->dev,
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"Unexpected IRQ: %s\n"
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" instance: %d: channel: %d [enabled: %x]\n",
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mdev->name, chan_info->instance,
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chan_info->channel, mdev->enabled[instance]);
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/* Only handle IRQ if no other valid IRQs were found */
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if (ret == IRQ_NONE)
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ret = IRQ_HANDLED;
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continue;
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}
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sti_mbox_disable_channel(chan);
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ret = IRQ_WAKE_THREAD;
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}
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if (ret == IRQ_NONE)
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dev_err(mdev->dev, "Spurious IRQ - was a channel requested?\n");
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return ret;
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}
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static bool sti_mbox_tx_is_ready(struct mbox_chan *chan)
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{
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struct sti_channel *chan_info = chan->con_priv;
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struct sti_mbox_device *mdev = chan_info->mdev;
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unsigned int instance = chan_info->instance;
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unsigned int channel = chan_info->channel;
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void __iomem *base = MBOX_BASE(mdev, instance);
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if (!(readl_relaxed(base + STI_ENA_VAL_OFFSET) & BIT(channel))) {
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dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d disabled\n",
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mdev->name, instance, channel);
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return false;
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}
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if (readl_relaxed(base + STI_IRQ_VAL_OFFSET) & BIT(channel)) {
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dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d not ready\n",
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mdev->name, instance, channel);
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return false;
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}
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return true;
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}
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static int sti_mbox_send_data(struct mbox_chan *chan, void *data)
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{
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struct sti_channel *chan_info = chan->con_priv;
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struct sti_mbox_device *mdev = chan_info->mdev;
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unsigned int instance = chan_info->instance;
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unsigned int channel = chan_info->channel;
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void __iomem *base = MBOX_BASE(mdev, instance);
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/* Send event to co-processor */
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writel_relaxed(BIT(channel), base + STI_IRQ_SET_OFFSET);
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dev_dbg(mdev->dev,
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"Sent via Mailbox %s: instance: %d channel: %d\n",
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mdev->name, instance, channel);
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return 0;
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}
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static int sti_mbox_startup_chan(struct mbox_chan *chan)
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{
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sti_mbox_clear_irq(chan);
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sti_mbox_enable_channel(chan);
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return 0;
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}
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static void sti_mbox_shutdown_chan(struct mbox_chan *chan)
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{
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struct sti_channel *chan_info = chan->con_priv;
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struct mbox_controller *mbox = chan_info->mdev->mbox;
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int i;
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for (i = 0; i < mbox->num_chans; i++)
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if (chan == &mbox->chans[i])
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break;
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if (mbox->num_chans == i) {
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dev_warn(mbox->dev, "Request to free non-existent channel\n");
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return;
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}
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/* Reset channel */
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sti_mbox_disable_channel(chan);
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sti_mbox_clear_irq(chan);
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chan->con_priv = NULL;
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}
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static struct mbox_chan *sti_mbox_xlate(struct mbox_controller *mbox,
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const struct of_phandle_args *spec)
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{
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struct sti_mbox_device *mdev = dev_get_drvdata(mbox->dev);
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struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
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struct sti_channel *chan_info;
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struct mbox_chan *chan = NULL;
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unsigned int instance = spec->args[0];
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unsigned int channel = spec->args[1];
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int i;
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/* Bounds checking */
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if (instance >= pdata->num_inst || channel >= pdata->num_chan) {
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dev_err(mbox->dev,
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"Invalid channel requested instance: %d channel: %d\n",
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instance, channel);
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return ERR_PTR(-EINVAL);
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}
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for (i = 0; i < mbox->num_chans; i++) {
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chan_info = mbox->chans[i].con_priv;
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/* Is requested channel free? */
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if (chan_info &&
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mbox->dev == chan_info->mdev->dev &&
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instance == chan_info->instance &&
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channel == chan_info->channel) {
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dev_err(mbox->dev, "Channel in use\n");
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return ERR_PTR(-EBUSY);
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}
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/*
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* Find the first free slot, then continue checking
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* to see if requested channel is in use
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*/
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if (!chan && !chan_info)
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chan = &mbox->chans[i];
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}
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if (!chan) {
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dev_err(mbox->dev, "No free channels left\n");
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return ERR_PTR(-EBUSY);
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}
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chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL);
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if (!chan_info)
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return ERR_PTR(-ENOMEM);
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chan_info->mdev = mdev;
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chan_info->instance = instance;
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chan_info->channel = channel;
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chan->con_priv = chan_info;
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dev_info(mbox->dev,
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"Mbox: %s: Created channel: instance: %d channel: %d\n",
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mdev->name, instance, channel);
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return chan;
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}
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static struct mbox_chan_ops sti_mbox_ops = {
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.startup = sti_mbox_startup_chan,
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.shutdown = sti_mbox_shutdown_chan,
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.send_data = sti_mbox_send_data,
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.last_tx_done = sti_mbox_tx_is_ready,
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};
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static const struct sti_mbox_pdata mbox_stih407_pdata = {
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.num_inst = 4,
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.num_chan = 32,
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};
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static const struct of_device_id sti_mailbox_match[] = {
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{
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.compatible = "st,stih407-mailbox",
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.data = (void *)&mbox_stih407_pdata
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},
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{ }
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};
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static int sti_mbox_probe(struct platform_device *pdev)
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{
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const struct of_device_id *match;
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struct mbox_controller *mbox;
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struct sti_mbox_device *mdev;
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struct device_node *np = pdev->dev.of_node;
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struct mbox_chan *chans;
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struct resource *res;
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int irq;
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int ret;
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match = of_match_device(sti_mailbox_match, &pdev->dev);
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if (!match) {
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dev_err(&pdev->dev, "No configuration found\n");
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return -ENODEV;
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}
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pdev->dev.platform_data = (struct sti_mbox_pdata *) match->data;
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mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
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if (!mdev)
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return -ENOMEM;
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platform_set_drvdata(pdev, mdev);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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mdev->base = devm_ioremap_resource(&pdev->dev, res);
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if (!mdev->base)
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return -ENOMEM;
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ret = of_property_read_string(np, "mbox-name", &mdev->name);
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if (ret)
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mdev->name = np->full_name;
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mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
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if (!mbox)
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return -ENOMEM;
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chans = devm_kzalloc(&pdev->dev,
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sizeof(*chans) * STI_MBOX_CHAN_MAX, GFP_KERNEL);
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if (!chans)
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return -ENOMEM;
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mdev->dev = &pdev->dev;
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mdev->mbox = mbox;
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spin_lock_init(&mdev->lock);
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|
||||
/* STi Mailbox does not have a Tx-Done or Tx-Ready IRQ */
|
||||
mbox->txdone_irq = false;
|
||||
mbox->txdone_poll = true;
|
||||
mbox->txpoll_period = 100;
|
||||
mbox->ops = &sti_mbox_ops;
|
||||
mbox->dev = mdev->dev;
|
||||
mbox->of_xlate = sti_mbox_xlate;
|
||||
mbox->chans = chans;
|
||||
mbox->num_chans = STI_MBOX_CHAN_MAX;
|
||||
|
||||
ret = mbox_controller_register(mbox);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
/* It's okay for Tx Mailboxes to not supply IRQs */
|
||||
irq = platform_get_irq(pdev, 0);
|
||||
if (irq < 0) {
|
||||
dev_info(&pdev->dev,
|
||||
"%s: Registered Tx only Mailbox\n", mdev->name);
|
||||
return 0;
|
||||
}
|
||||
|
||||
ret = devm_request_threaded_irq(&pdev->dev, irq,
|
||||
sti_mbox_irq_handler,
|
||||
sti_mbox_thread_handler,
|
||||
IRQF_ONESHOT, mdev->name, mdev);
|
||||
if (ret) {
|
||||
dev_err(&pdev->dev, "Can't claim IRQ %d\n", irq);
|
||||
mbox_controller_unregister(mbox);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
dev_info(&pdev->dev, "%s: Registered Tx/Rx Mailbox\n", mdev->name);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int sti_mbox_remove(struct platform_device *pdev)
|
||||
{
|
||||
struct sti_mbox_device *mdev = platform_get_drvdata(pdev);
|
||||
|
||||
mbox_controller_unregister(mdev->mbox);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct platform_driver sti_mbox_driver = {
|
||||
.probe = sti_mbox_probe,
|
||||
.remove = sti_mbox_remove,
|
||||
.driver = {
|
||||
.name = "sti-mailbox",
|
||||
.of_match_table = sti_mailbox_match,
|
||||
},
|
||||
};
|
||||
module_platform_driver(sti_mbox_driver);
|
||||
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_DESCRIPTION("STMicroelectronics Mailbox Controller");
|
||||
MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
|
||||
MODULE_ALIAS("platform:mailbox-sti");
|
||||
Loading…
Reference in New Issue