linux/drivers/mailbox/mailbox-sti.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

500 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* STi Mailbox
*
* Copyright (C) 2015 ST Microelectronics
*
* Author: Lee Jones <lee.jones@linaro.org> for ST Microelectronics
*
* Based on the original driver written by;
* Alexandre Torgue, Olivier Lebreton and Loic Pallardy
*/
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mailbox_controller.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include "mailbox.h"
#define STI_MBOX_INST_MAX 4 /* RAM saving: Max supported instances */
#define STI_MBOX_CHAN_MAX 20 /* RAM saving: Max supported channels */
#define STI_IRQ_VAL_OFFSET 0x04 /* Read interrupt status */
#define STI_IRQ_SET_OFFSET 0x24 /* Generate a Tx channel interrupt */
#define STI_IRQ_CLR_OFFSET 0x44 /* Clear pending Rx interrupts */
#define STI_ENA_VAL_OFFSET 0x64 /* Read enable status */
#define STI_ENA_SET_OFFSET 0x84 /* Enable a channel */
#define STI_ENA_CLR_OFFSET 0xa4 /* Disable a channel */
#define MBOX_BASE(mdev, inst) ((mdev)->base + ((inst) * 4))
/**
* STi Mailbox device data
*
* An IP Mailbox is currently composed of 4 instances
* Each instance is currently composed of 32 channels
* This means that we have 128 channels per Mailbox
* A channel an be used for TX or RX
*
* @dev: Device to which it is attached
* @mbox: Representation of a communication channel controller
* @base: Base address of the register mapping region
* @name: Name of the mailbox
* @enabled: Local copy of enabled channels
* @lock: Mutex protecting enabled status
*/
struct sti_mbox_device {
struct device *dev;
struct mbox_controller *mbox;
void __iomem *base;
const char *name;
u32 enabled[STI_MBOX_INST_MAX];
spinlock_t lock;
};
/**
* STi Mailbox platform specific configuration
*
* @num_inst: Maximum number of instances in one HW Mailbox
* @num_chan: Maximum number of channel per instance
*/
struct sti_mbox_pdata {
unsigned int num_inst;
unsigned int num_chan;
};
/**
* STi Mailbox allocated channel information
*
* @mdev: Pointer to parent Mailbox device
* @instance: Instance number channel resides in
* @channel: Channel number pertaining to this container
*/
struct sti_channel {
struct sti_mbox_device *mdev;
unsigned int instance;
unsigned int channel;
};
static inline bool sti_mbox_channel_is_enabled(struct mbox_chan *chan)
{
struct sti_channel *chan_info = chan->con_priv;
struct sti_mbox_device *mdev = chan_info->mdev;
unsigned int instance = chan_info->instance;
unsigned int channel = chan_info->channel;
return mdev->enabled[instance] & BIT(channel);
}
static inline
struct mbox_chan *sti_mbox_to_channel(struct mbox_controller *mbox,
unsigned int instance,
unsigned int channel)
{
struct sti_channel *chan_info;
int i;
for (i = 0; i < mbox->num_chans; i++) {
chan_info = mbox->chans[i].con_priv;
if (chan_info &&
chan_info->instance == instance &&
chan_info->channel == channel)
return &mbox->chans[i];
}
dev_err(mbox->dev,
"Channel not registered: instance: %d channel: %d\n",
instance, channel);
return NULL;
}
static void sti_mbox_enable_channel(struct mbox_chan *chan)
{
struct sti_channel *chan_info = chan->con_priv;
struct sti_mbox_device *mdev = chan_info->mdev;
unsigned int instance = chan_info->instance;
unsigned int channel = chan_info->channel;
unsigned long flags;
void __iomem *base = MBOX_BASE(mdev, instance);
spin_lock_irqsave(&mdev->lock, flags);
mdev->enabled[instance] |= BIT(channel);
writel_relaxed(BIT(channel), base + STI_ENA_SET_OFFSET);
spin_unlock_irqrestore(&mdev->lock, flags);
}
static void sti_mbox_disable_channel(struct mbox_chan *chan)
{
struct sti_channel *chan_info = chan->con_priv;
struct sti_mbox_device *mdev = chan_info->mdev;
unsigned int instance = chan_info->instance;
unsigned int channel = chan_info->channel;
unsigned long flags;
void __iomem *base = MBOX_BASE(mdev, instance);
spin_lock_irqsave(&mdev->lock, flags);
mdev->enabled[instance] &= ~BIT(channel);
writel_relaxed(BIT(channel), base + STI_ENA_CLR_OFFSET);
spin_unlock_irqrestore(&mdev->lock, flags);
}
static void sti_mbox_clear_irq(struct mbox_chan *chan)
{
struct sti_channel *chan_info = chan->con_priv;
struct sti_mbox_device *mdev = chan_info->mdev;
unsigned int instance = chan_info->instance;
unsigned int channel = chan_info->channel;
void __iomem *base = MBOX_BASE(mdev, instance);
writel_relaxed(BIT(channel), base + STI_IRQ_CLR_OFFSET);
}
static struct mbox_chan *sti_mbox_irq_to_channel(struct sti_mbox_device *mdev,
unsigned int instance)
{
struct mbox_controller *mbox = mdev->mbox;
struct mbox_chan *chan = NULL;
unsigned int channel;
unsigned long bits;
void __iomem *base = MBOX_BASE(mdev, instance);
bits = readl_relaxed(base + STI_IRQ_VAL_OFFSET);
if (!bits)
/* No IRQs fired in specified instance */
return NULL;
/* An IRQ has fired, find the associated channel */
for (channel = 0; bits; channel++) {
if (!test_and_clear_bit(channel, &bits))
continue;
chan = sti_mbox_to_channel(mbox, instance, channel);
if (chan) {
dev_dbg(mbox->dev,
"IRQ fired on instance: %d channel: %d\n",
instance, channel);
break;
}
}
return chan;
}
static irqreturn_t sti_mbox_thread_handler(int irq, void *data)
{
struct sti_mbox_device *mdev = data;
struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
struct mbox_chan *chan;
unsigned int instance;
for (instance = 0; instance < pdata->num_inst; instance++) {
keep_looking:
chan = sti_mbox_irq_to_channel(mdev, instance);
if (!chan)
continue;
mbox_chan_received_data(chan, NULL);
sti_mbox_clear_irq(chan);
sti_mbox_enable_channel(chan);
goto keep_looking;
}
return IRQ_HANDLED;
}
static irqreturn_t sti_mbox_irq_handler(int irq, void *data)
{
struct sti_mbox_device *mdev = data;
struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
struct sti_channel *chan_info;
struct mbox_chan *chan;
unsigned int instance;
int ret = IRQ_NONE;
for (instance = 0; instance < pdata->num_inst; instance++) {
chan = sti_mbox_irq_to_channel(mdev, instance);
if (!chan)
continue;
chan_info = chan->con_priv;
if (!sti_mbox_channel_is_enabled(chan)) {
dev_warn(mdev->dev,
"Unexpected IRQ: %s\n"
" instance: %d: channel: %d [enabled: %x]\n",
mdev->name, chan_info->instance,
chan_info->channel, mdev->enabled[instance]);
/* Only handle IRQ if no other valid IRQs were found */
if (ret == IRQ_NONE)
ret = IRQ_HANDLED;
continue;
}
sti_mbox_disable_channel(chan);
ret = IRQ_WAKE_THREAD;
}
if (ret == IRQ_NONE)
dev_err(mdev->dev, "Spurious IRQ - was a channel requested?\n");
return ret;
}
static bool sti_mbox_tx_is_ready(struct mbox_chan *chan)
{
struct sti_channel *chan_info = chan->con_priv;
struct sti_mbox_device *mdev = chan_info->mdev;
unsigned int instance = chan_info->instance;
unsigned int channel = chan_info->channel;
void __iomem *base = MBOX_BASE(mdev, instance);
if (!(readl_relaxed(base + STI_ENA_VAL_OFFSET) & BIT(channel))) {
dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d disabled\n",
mdev->name, instance, channel);
return false;
}
if (readl_relaxed(base + STI_IRQ_VAL_OFFSET) & BIT(channel)) {
dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d not ready\n",
mdev->name, instance, channel);
return false;
}
return true;
}
static int sti_mbox_send_data(struct mbox_chan *chan, void *data)
{
struct sti_channel *chan_info = chan->con_priv;
struct sti_mbox_device *mdev = chan_info->mdev;
unsigned int instance = chan_info->instance;
unsigned int channel = chan_info->channel;
void __iomem *base = MBOX_BASE(mdev, instance);
/* Send event to co-processor */
writel_relaxed(BIT(channel), base + STI_IRQ_SET_OFFSET);
dev_dbg(mdev->dev,
"Sent via Mailbox %s: instance: %d channel: %d\n",
mdev->name, instance, channel);
return 0;
}
static int sti_mbox_startup_chan(struct mbox_chan *chan)
{
sti_mbox_clear_irq(chan);
sti_mbox_enable_channel(chan);
return 0;
}
static void sti_mbox_shutdown_chan(struct mbox_chan *chan)
{
struct sti_channel *chan_info = chan->con_priv;
struct mbox_controller *mbox = chan_info->mdev->mbox;
int i;
for (i = 0; i < mbox->num_chans; i++)
if (chan == &mbox->chans[i])
break;
if (mbox->num_chans == i) {
dev_warn(mbox->dev, "Request to free non-existent channel\n");
return;
}
/* Reset channel */
sti_mbox_disable_channel(chan);
sti_mbox_clear_irq(chan);
chan->con_priv = NULL;
}
static struct mbox_chan *sti_mbox_xlate(struct mbox_controller *mbox,
const struct of_phandle_args *spec)
{
struct sti_mbox_device *mdev = dev_get_drvdata(mbox->dev);
struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
struct sti_channel *chan_info;
struct mbox_chan *chan = NULL;
unsigned int instance = spec->args[0];
unsigned int channel = spec->args[1];
int i;
/* Bounds checking */
if (instance >= pdata->num_inst || channel >= pdata->num_chan) {
dev_err(mbox->dev,
"Invalid channel requested instance: %d channel: %d\n",
instance, channel);
return ERR_PTR(-EINVAL);
}
for (i = 0; i < mbox->num_chans; i++) {
chan_info = mbox->chans[i].con_priv;
/* Is requested channel free? */
if (chan_info &&
mbox->dev == chan_info->mdev->dev &&
instance == chan_info->instance &&
channel == chan_info->channel) {
dev_err(mbox->dev, "Channel in use\n");
return ERR_PTR(-EBUSY);
}
/*
* Find the first free slot, then continue checking
* to see if requested channel is in use
*/
if (!chan && !chan_info)
chan = &mbox->chans[i];
}
if (!chan) {
dev_err(mbox->dev, "No free channels left\n");
return ERR_PTR(-EBUSY);
}
chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL);
if (!chan_info)
return ERR_PTR(-ENOMEM);
chan_info->mdev = mdev;
chan_info->instance = instance;
chan_info->channel = channel;
chan->con_priv = chan_info;
dev_info(mbox->dev,
"Mbox: %s: Created channel: instance: %d channel: %d\n",
mdev->name, instance, channel);
return chan;
}
static const struct mbox_chan_ops sti_mbox_ops = {
.startup = sti_mbox_startup_chan,
.shutdown = sti_mbox_shutdown_chan,
.send_data = sti_mbox_send_data,
.last_tx_done = sti_mbox_tx_is_ready,
};
static const struct sti_mbox_pdata mbox_stih407_pdata = {
.num_inst = 4,
.num_chan = 32,
};
static const struct of_device_id sti_mailbox_match[] = {
{
.compatible = "st,stih407-mailbox",
.data = (void *)&mbox_stih407_pdata
},
{ }
};
MODULE_DEVICE_TABLE(of, sti_mailbox_match);
static int sti_mbox_probe(struct platform_device *pdev)
{
const struct of_device_id *match;
struct mbox_controller *mbox;
struct sti_mbox_device *mdev;
struct device_node *np = pdev->dev.of_node;
struct mbox_chan *chans;
struct resource *res;
int irq;
int ret;
match = of_match_device(sti_mailbox_match, &pdev->dev);
if (!match) {
dev_err(&pdev->dev, "No configuration found\n");
return -ENODEV;
}
pdev->dev.platform_data = (struct sti_mbox_pdata *) match->data;
mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
if (!mdev)
return -ENOMEM;
platform_set_drvdata(pdev, mdev);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mdev->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(mdev->base))
return PTR_ERR(mdev->base);
ret = of_property_read_string(np, "mbox-name", &mdev->name);
if (ret)
mdev->name = np->full_name;
mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
if (!mbox)
return -ENOMEM;
chans = devm_kcalloc(&pdev->dev,
STI_MBOX_CHAN_MAX, sizeof(*chans), GFP_KERNEL);
if (!chans)
return -ENOMEM;
mdev->dev = &pdev->dev;
mdev->mbox = mbox;
spin_lock_init(&mdev->lock);
/* 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 = devm_mbox_controller_register(&pdev->dev, 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);
return -EINVAL;
}
dev_info(&pdev->dev, "%s: Registered Tx/Rx Mailbox\n", mdev->name);
return 0;
}
static struct platform_driver sti_mbox_driver = {
.probe = sti_mbox_probe,
.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");