// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017-2018 HiSilicon Limited.
// Copyright (c) 2017-2018 Linaro Limited.
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/mailbox_controller.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include "mailbox.h"
#define MBOX_CHAN_MAX 32
#define MBOX_RX 0x0
#define MBOX_TX 0x1
#define MBOX_BASE(mbox, ch) ((mbox)->base + ((ch) * 0x40))
#define MBOX_SRC_REG 0x00
#define MBOX_DST_REG 0x04
#define MBOX_DCLR_REG 0x08
#define MBOX_DSTAT_REG 0x0c
#define MBOX_MODE_REG 0x10
#define MBOX_IMASK_REG 0x14
#define MBOX_ICLR_REG 0x18
#define MBOX_SEND_REG 0x1c
#define MBOX_DATA_REG 0x20
#define MBOX_IPC_LOCK_REG 0xa00
#define MBOX_IPC_UNLOCK 0x1acce551
#define MBOX_AUTOMATIC_ACK 1
#define MBOX_STATE_IDLE BIT(4)
#define MBOX_STATE_READY BIT(5)
#define MBOX_STATE_ACK BIT(7)
#define MBOX_MSG_LEN 8
/**
* struct hi3660_chan_info - Hi3660 mailbox channel information
* @dst_irq: Interrupt vector for remote processor
* @ack_irq: Interrupt vector for local processor
*
* A channel can be used for TX or RX, it can trigger remote
* processor interrupt to notify remote processor and can receive
* interrupt if it has an incoming message.
*/
struct hi3660_chan_info {
unsigned int dst_irq;
unsigned int ack_irq;
};
/**
* struct hi3660_mbox - Hi3660 mailbox controller data
* @dev: Device to which it is attached
* @base: Base address of the register mapping region
* @chan: Representation of channels in mailbox controller
* @mchan: Representation of channel info
* @controller: Representation of a communication channel controller
*
* Mailbox controller includes 32 channels and can allocate
* channel for message transferring.
*/
struct hi3660_mbox {
struct device *dev;
void __iomem *base;
struct mbox_chan chan[MBOX_CHAN_MAX];
struct hi3660_chan_info mchan[MBOX_CHAN_MAX];
struct mbox_controller controller;
};
static struct hi3660_mbox *to_hi3660_mbox(struct mbox_controller *mbox)
{
return container_of(mbox, struct hi3660_mbox, controller);
}
static int hi3660_mbox_check_state(struct mbox_chan *chan)
{
unsigned long ch = (unsigned long)chan->con_priv;
struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
struct hi3660_chan_info *mchan = &mbox->mchan[ch];
void __iomem *base = MBOX_BASE(mbox, ch);
unsigned long val;
unsigned int ret;
/* Mailbox is ready to use */
if (readl(base + MBOX_MODE_REG) & MBOX_STATE_READY)
return 0;
/* Wait for acknowledge from remote */
ret = readx_poll_timeout_atomic(readl, base + MBOX_MODE_REG,
val, (val & MBOX_STATE_ACK), 1000, 300000);
if (ret) {
dev_err(mbox->dev, "%s: timeout for receiving ack\n", __func__);
return ret;
}
/* clear ack state, mailbox will get back to ready state */
writel(BIT(mchan->ack_irq), base + MBOX_ICLR_REG);
return 0;
}
static int hi3660_mbox_unlock(struct mbox_chan *chan)
{
struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
unsigned int val, retry = 3;
do {
writel(MBOX_IPC_UNLOCK, mbox->base + MBOX_IPC_LOCK_REG);
val = readl(mbox->base + MBOX_IPC_LOCK_REG);
if (!val)
break;
udelay(10);
} while (retry--);
if (val)
dev_err(mbox->dev, "%s: failed to unlock mailbox\n", __func__);
return (!val) ? 0 : -ETIMEDOUT;
}
static int hi3660_mbox_acquire_channel(struct mbox_chan *chan)
{
unsigned long ch = (unsigned long)chan->con_priv;
struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
struct hi3660_chan_info *mchan = &mbox->mchan[ch];
void __iomem *base = MBOX_BASE(mbox, ch);
unsigned int val, retry;
for (retry = 10; retry; retry--) {
/* Check if channel is in idle state */
if (readl(base + MBOX_MODE_REG) & MBOX_STATE_IDLE) {
writel(BIT(mchan->ack_irq), base + MBOX_SRC_REG);
/* Check ack bit has been set successfully */
val = readl(base + MBOX_SRC_REG);
if (val & BIT(mchan->ack_irq))
break;
}
}
if (!retry)
dev_err(mbox->dev, "%s: failed to acquire channel\n", __func__);
return retry ? 0 : -ETIMEDOUT;
}
static int hi3660_mbox_startup(struct mbox_chan *chan)
{
int ret;
ret = hi3660_mbox_unlock(chan);
if (ret)
return ret;
ret = hi3660_mbox_acquire_channel(chan);
if (ret)
return ret;
return 0;
}
static int hi3660_mbox_send_data(struct mbox_chan *chan, void *msg)
{
unsigned long ch = (unsigned long)chan->con_priv;
struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
struct hi3660_chan_info *mchan = &mbox->mchan[ch];
void __iomem *base = MBOX_BASE(mbox, ch);
u32 *buf = msg;
unsigned int i;
int ret;
ret = hi3660_mbox_check_state(chan);
if (ret)
return ret;
/* Clear mask for destination interrupt */
writel_relaxed(~BIT(mchan->dst_irq), base + MBOX_IMASK_REG);
/* Config destination for interrupt vector */
writel_relaxed(BIT(mchan->dst_irq), base + MBOX_DST_REG);
/* Automatic acknowledge mode */
writel_relaxed(MBOX_AUTOMATIC_ACK, base + MBOX_MODE_REG);
/* Fill message data */
for (i = 0; i < MBOX_MSG_LEN; i++)
writel_relaxed(buf[i], base + MBOX_DATA_REG + i * 4);
/* Trigger data transferring */
writel(BIT(mchan->ack_irq), base + MBOX_SEND_REG);
return 0;
}
static const struct mbox_chan_ops hi3660_mbox_ops = {
.startup = hi3660_mbox_startup,
.send_data = hi3660_mbox_send_data,
};
static struct mbox_chan *hi3660_mbox_xlate(struct mbox_controller *controller,
const struct of_phandle_args *spec)
{
struct hi3660_mbox *mbox = to_hi3660_mbox(controller);
struct hi3660_chan_info *mchan;
unsigned int ch = spec->args[0];
if (ch >= MBOX_CHAN_MAX) {
dev_err(mbox->dev, "Invalid channel idx %d\n", ch);
return ERR_PTR(-EINVAL);
}
mchan = &mbox->mchan[ch];
mchan->dst_irq = spec->args[1];
mchan->ack_irq = spec->args[2];
return &mbox->chan[ch];
}
static const struct of_device_id hi3660_mbox_of_match[] = {
{ .compatible = "hisilicon,hi3660-mbox", },
{},
};
MODULE_DEVICE_TABLE(of, hi3660_mbox_of_match);
static int hi3660_mbox_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct hi3660_mbox *mbox;
struct mbox_chan *chan;
unsigned long ch;
int err;
mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
if (!mbox)
return -ENOMEM;
mbox->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(mbox->base))
return PTR_ERR(mbox->base);
mbox->dev = dev;
mbox->controller.dev = dev;
mbox->controller.chans = mbox->chan;
mbox->controller.num_chans = MBOX_CHAN_MAX;
mbox->controller.ops = &hi3660_mbox_ops;
mbox->controller.of_xlate = hi3660_mbox_xlate;
/* Initialize mailbox channel data */
chan = mbox->chan;
for (ch = 0; ch < MBOX_CHAN_MAX; ch++)
chan[ch].con_priv = (void *)ch;
err = devm_mbox_controller_register(dev, &mbox->controller);
if (err) {
dev_err(dev, "Failed to register mailbox %d\n", err);
return err;
}
platform_set_drvdata(pdev, mbox);
dev_info(dev, "Mailbox enabled\n");
return 0;
}
static struct platform_driver hi3660_mbox_driver = {
.probe = hi3660_mbox_probe,
.driver = {
.name = "hi3660-mbox",
.of_match_table = hi3660_mbox_of_match,
},
};
static int __init hi3660_mbox_init(void)
{
return platform_driver_register(&hi3660_mbox_driver);
}
core_initcall(hi3660_mbox_init);
static void __exit hi3660_mbox_exit(void)
{
platform_driver_unregister(&hi3660_mbox_driver);
}
module_exit(hi3660_mbox_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Hisilicon Hi3660 Mailbox Controller");
MODULE_AUTHOR("Leo Yan <[email protected]>");
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