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// SPDX-License-Identifier: GPL-2.0-only
/*
* Hisilicon's Hi6220 mailbox driver
*
* Copyright (c) 2015 HiSilicon Limited.
* Copyright (c) 2015 Linaro Limited.
*
* Author: Leo Yan <leo.yan@linaro.org>
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kfifo.h>
#include <linux/mailbox_controller.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#define MBOX_CHAN_MAX 32
#define MBOX_TX 0x1
/* Mailbox message length: 8 words */
#define MBOX_MSG_LEN 8
/* Mailbox Registers */
#define MBOX_OFF(m) (0x40 * (m))
#define MBOX_MODE_REG(m) (MBOX_OFF(m) + 0x0)
#define MBOX_DATA_REG(m) (MBOX_OFF(m) + 0x4)
#define MBOX_STATE_MASK (0xF << 4)
#define MBOX_STATE_IDLE (0x1 << 4)
#define MBOX_STATE_TX (0x2 << 4)
#define MBOX_STATE_RX (0x4 << 4)
#define MBOX_STATE_ACK (0x8 << 4)
#define MBOX_ACK_CONFIG_MASK (0x1 << 0)
#define MBOX_ACK_AUTOMATIC (0x1 << 0)
#define MBOX_ACK_IRQ (0x0 << 0)
/* IPC registers */
#define ACK_INT_RAW_REG(i) ((i) + 0x400)
#define ACK_INT_MSK_REG(i) ((i) + 0x404)
#define ACK_INT_STAT_REG(i) ((i) + 0x408)
#define ACK_INT_CLR_REG(i) ((i) + 0x40c)
#define ACK_INT_ENA_REG(i) ((i) + 0x500)
#define ACK_INT_DIS_REG(i) ((i) + 0x504)
#define DST_INT_RAW_REG(i) ((i) + 0x420)
struct hi6220_mbox_chan {
/*
* Description for channel's hardware info:
* - direction: tx or rx
* - dst irq: peer core's irq number
* - ack irq: local irq number
* - slot number
*/
unsigned int dir, dst_irq, ack_irq;
unsigned int slot;
struct hi6220_mbox *parent;
};
struct hi6220_mbox {
struct device *dev;
int irq;
/* flag of enabling tx's irq mode */
bool tx_irq_mode;
/* region for ipc event */
void __iomem *ipc;
/* region for mailbox */
void __iomem *base;
unsigned int chan_num;
struct hi6220_mbox_chan *mchan;
void *irq_map_chan[MBOX_CHAN_MAX];
struct mbox_chan *chan;
struct mbox_controller controller;
};
static void mbox_set_state(struct hi6220_mbox *mbox,
unsigned int slot, u32 val)
{
u32 status;
status = readl(mbox->base + MBOX_MODE_REG(slot));
status = (status & ~MBOX_STATE_MASK) | val;
writel(status, mbox->base + MBOX_MODE_REG(slot));
}
static void mbox_set_mode(struct hi6220_mbox *mbox,
unsigned int slot, u32 val)
{
u32 mode;
mode = readl(mbox->base + MBOX_MODE_REG(slot));
mode = (mode & ~MBOX_ACK_CONFIG_MASK) | val;
writel(mode, mbox->base + MBOX_MODE_REG(slot));
}
static bool hi6220_mbox_last_tx_done(struct mbox_chan *chan)
{
struct hi6220_mbox_chan *mchan = chan->con_priv;
struct hi6220_mbox *mbox = mchan->parent;
u32 state;
/* Only set idle state for polling mode */
BUG_ON(mbox->tx_irq_mode);
state = readl(mbox->base + MBOX_MODE_REG(mchan->slot));
return ((state & MBOX_STATE_MASK) == MBOX_STATE_IDLE);
}
static int hi6220_mbox_send_data(struct mbox_chan *chan, void *msg)
{
struct hi6220_mbox_chan *mchan = chan->con_priv;
struct hi6220_mbox *mbox = mchan->parent;
unsigned int slot = mchan->slot;
u32 *buf = msg;
int i;
/* indicate as a TX channel */
mchan->dir = MBOX_TX;
mbox_set_state(mbox, slot, MBOX_STATE_TX);
if (mbox->tx_irq_mode)
mbox_set_mode(mbox, slot, MBOX_ACK_IRQ);
else
mbox_set_mode(mbox, slot, MBOX_ACK_AUTOMATIC);
for (i = 0; i < MBOX_MSG_LEN; i++)
writel(buf[i], mbox->base + MBOX_DATA_REG(slot) + i * 4);
/* trigger remote request */
writel(BIT(mchan->dst_irq), DST_INT_RAW_REG(mbox->ipc));
return 0;
}
static irqreturn_t hi6220_mbox_interrupt(int irq, void *p)
{
struct hi6220_mbox *mbox = p;
struct hi6220_mbox_chan *mchan;
struct mbox_chan *chan;
unsigned int state, intr_bit, i;
u32 msg[MBOX_MSG_LEN];
state = readl(ACK_INT_STAT_REG(mbox->ipc));
if (!state) {
dev_warn(mbox->dev, "%s: spurious interrupt\n",
__func__);
return IRQ_HANDLED;
}
while (state) {
intr_bit = __ffs(state);
state &= (state - 1);
chan = mbox->irq_map_chan[intr_bit];
if (!chan) {
dev_warn(mbox->dev, "%s: unexpected irq vector %d\n",
__func__, intr_bit);
continue;
}
mchan = chan->con_priv;
if (mchan->dir == MBOX_TX)
mbox_chan_txdone(chan, 0);
else {
for (i = 0; i < MBOX_MSG_LEN; i++)
msg[i] = readl(mbox->base +
MBOX_DATA_REG(mchan->slot) + i * 4);
mbox_chan_received_data(chan, (void *)msg);
}
/* clear IRQ source */
writel(BIT(mchan->ack_irq), ACK_INT_CLR_REG(mbox->ipc));
mbox_set_state(mbox, mchan->slot, MBOX_STATE_IDLE);
}
return IRQ_HANDLED;
}
static int hi6220_mbox_startup(struct mbox_chan *chan)
{
struct hi6220_mbox_chan *mchan = chan->con_priv;
struct hi6220_mbox *mbox = mchan->parent;
mchan->dir = 0;
/* enable interrupt */
writel(BIT(mchan->ack_irq), ACK_INT_ENA_REG(mbox->ipc));
return 0;
}
static void hi6220_mbox_shutdown(struct mbox_chan *chan)
{
struct hi6220_mbox_chan *mchan = chan->con_priv;
struct hi6220_mbox *mbox = mchan->parent;
/* disable interrupt */
writel(BIT(mchan->ack_irq), ACK_INT_DIS_REG(mbox->ipc));
mbox->irq_map_chan[mchan->ack_irq] = NULL;
}
static const struct mbox_chan_ops hi6220_mbox_ops = {
.send_data = hi6220_mbox_send_data,
.startup = hi6220_mbox_startup,
.shutdown = hi6220_mbox_shutdown,
.last_tx_done = hi6220_mbox_last_tx_done,
};
static struct mbox_chan *hi6220_mbox_xlate(struct mbox_controller *controller,
const struct of_phandle_args *spec)
{
struct hi6220_mbox *mbox = dev_get_drvdata(controller->dev);
struct hi6220_mbox_chan *mchan;
struct mbox_chan *chan;
unsigned int i = spec->args[0];
unsigned int dst_irq = spec->args[1];
unsigned int ack_irq = spec->args[2];
/* Bounds checking */
if (i >= mbox->chan_num || dst_irq >= mbox->chan_num ||
ack_irq >= mbox->chan_num) {
dev_err(mbox->dev,
"Invalid channel idx %d dst_irq %d ack_irq %d\n",
i, dst_irq, ack_irq);
return ERR_PTR(-EINVAL);
}
/* Is requested channel free? */
chan = &mbox->chan[i];
if (mbox->irq_map_chan[ack_irq] == (void *)chan) {
dev_err(mbox->dev, "Channel in use\n");
return ERR_PTR(-EBUSY);
}
mchan = chan->con_priv;
mchan->dst_irq = dst_irq;
mchan->ack_irq = ack_irq;
mbox->irq_map_chan[ack_irq] = (void *)chan;
return chan;
}
static const struct of_device_id hi6220_mbox_of_match[] = {
{ .compatible = "hisilicon,hi6220-mbox", },
{},
};
MODULE_DEVICE_TABLE(of, hi6220_mbox_of_match);
static int hi6220_mbox_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
struct device *dev = &pdev->dev;
struct hi6220_mbox *mbox;
int i, err;
mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
if (!mbox)
return -ENOMEM;
mbox->dev = dev;
mbox->chan_num = MBOX_CHAN_MAX;
mbox->mchan = devm_kcalloc(dev,
mbox->chan_num, sizeof(*mbox->mchan), GFP_KERNEL);
if (!mbox->mchan)
return -ENOMEM;
mbox->chan = devm_kcalloc(dev,
mbox->chan_num, sizeof(*mbox->chan), GFP_KERNEL);
if (!mbox->chan)
return -ENOMEM;
mbox->irq = platform_get_irq(pdev, 0);
if (mbox->irq < 0)
return mbox->irq;
mbox->ipc = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(mbox->ipc)) {
dev_err(dev, "ioremap ipc failed\n");
return PTR_ERR(mbox->ipc);
}
mbox->base = devm_platform_ioremap_resource(pdev, 1);
if (IS_ERR(mbox->base)) {
dev_err(dev, "ioremap buffer failed\n");
return PTR_ERR(mbox->base);
}
err = devm_request_irq(dev, mbox->irq, hi6220_mbox_interrupt, 0,
dev_name(dev), mbox);
if (err) {
dev_err(dev, "Failed to register a mailbox IRQ handler: %d\n",
err);
return -ENODEV;
}
mbox->controller.dev = dev;
mbox->controller.chans = &mbox->chan[0];
mbox->controller.num_chans = mbox->chan_num;
mbox->controller.ops = &hi6220_mbox_ops;
mbox->controller.of_xlate = hi6220_mbox_xlate;
for (i = 0; i < mbox->chan_num; i++) {
mbox->chan[i].con_priv = &mbox->mchan[i];
mbox->irq_map_chan[i] = NULL;
mbox->mchan[i].parent = mbox;
mbox->mchan[i].slot = i;
}
/* mask and clear all interrupt vectors */
writel(0x0, ACK_INT_MSK_REG(mbox->ipc));
writel(~0x0, ACK_INT_CLR_REG(mbox->ipc));
/* use interrupt for tx's ack */
mbox->tx_irq_mode = !of_property_read_bool(node, "hi6220,mbox-tx-noirq");
if (mbox->tx_irq_mode)
mbox->controller.txdone_irq = true;
else {
mbox->controller.txdone_poll = true;
mbox->controller.txpoll_period = 5;
}
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 hi6220_mbox_driver = {
.driver = {
.name = "hi6220-mbox",
.of_match_table = hi6220_mbox_of_match,
},
.probe = hi6220_mbox_probe,
};
static int __init hi6220_mbox_init(void)
{
return platform_driver_register(&hi6220_mbox_driver);
}
core_initcall(hi6220_mbox_init);
static void __exit hi6220_mbox_exit(void)
{
platform_driver_unregister(&hi6220_mbox_driver);
}
module_exit(hi6220_mbox_exit);
MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
MODULE_DESCRIPTION("Hi6220 mailbox driver");
MODULE_LICENSE("GPL v2");
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