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// SPDX-License-Identifier: GPL-2.0
/*
* Message Handling Unit version 2 controller driver
* Copyright (C) 2019 ARM Ltd.
*
* Based on drivers/mailbox/arm_mhu.c
*
*/
#include <linux/interrupt.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/amba/bus.h>
#include <linux/mailbox_controller.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#define MHU_V2_REG_STAT_OFS 0x0
#define MHU_V2_REG_CLR_OFS 0x8
#define MHU_V2_REG_SET_OFS 0xC
#define MHU_V2_REG_MSG_NO_CAP_OFS 0xF80
#define MHU_V2_REG_ACC_REQ_OFS 0xF88
#define MHU_V2_REG_ACC_RDY_OFS 0xF8C
#define MHU_V2_CHANS 2
#define mbox_to_arm_mhuv2(c) container_of(c, struct arm_mhuv2, mbox)
struct mhuv2_link {
unsigned int irq;
void __iomem *tx_reg;
void __iomem *rx_reg;
};
struct arm_mhuv2 {
void __iomem *base;
struct mhuv2_link mlink[MHU_V2_CHANS];
struct mbox_chan chan[MHU_V2_CHANS];
struct mbox_controller mbox;
};
static irqreturn_t mhuv2_rx_interrupt(int irq, void *p)
{
struct mbox_chan *chan = p;
struct mhuv2_link *mlink = chan->con_priv;
u32 val;
val = readl_relaxed(mlink->rx_reg + MHU_V2_REG_STAT_OFS);
if (!val)
return IRQ_NONE;
mbox_chan_received_data(chan, (void *)&val);
writel_relaxed(val, mlink->rx_reg + MHU_V2_REG_CLR_OFS);
return IRQ_HANDLED;
}
static bool mhuv2_last_tx_done(struct mbox_chan *chan)
{
struct mhuv2_link *mlink = chan->con_priv;
u32 val = readl_relaxed(mlink->tx_reg + MHU_V2_REG_STAT_OFS);
return (val == 0);
}
static int mhuv2_send_data(struct mbox_chan *chan, void *data)
{
struct mhuv2_link *mlink = chan->con_priv;
u32 *arg = data;
writel_relaxed(*arg, mlink->tx_reg + MHU_V2_REG_SET_OFS);
return 0;
}
static int mhuv2_startup(struct mbox_chan *chan)
{
struct mhuv2_link *mlink = chan->con_priv;
u32 val;
int ret;
struct arm_mhuv2 *mhuv2 = mbox_to_arm_mhuv2(chan->mbox);
writel_relaxed(0x1, mhuv2->base + MHU_V2_REG_ACC_REQ_OFS);
val = readl_relaxed(mlink->tx_reg + MHU_V2_REG_STAT_OFS);
writel_relaxed(val, mlink->tx_reg + MHU_V2_REG_CLR_OFS);
ret = request_irq(mlink->irq, mhuv2_rx_interrupt,
IRQF_SHARED, "mhuv2_link", chan);
if (ret) {
dev_err(chan->mbox->dev,
"unable to acquire IRQ %d\n", mlink->irq);
return ret;
}
return 0;
}
static void mhuv2_shutdown(struct mbox_chan *chan)
{
struct mhuv2_link *mlink = chan->con_priv;
struct arm_mhuv2 *mhuv2 = mbox_to_arm_mhuv2(chan->mbox);
writel_relaxed(0x0, mhuv2->base + MHU_V2_REG_ACC_REQ_OFS);
free_irq(mlink->irq, chan);
}
static const struct mbox_chan_ops mhuv2_ops = {
.send_data = mhuv2_send_data,
.startup = mhuv2_startup,
.shutdown = mhuv2_shutdown,
.last_tx_done = mhuv2_last_tx_done,
};
static int mhuv2_probe(struct amba_device *adev, const struct amba_id *id)
{
int i, err;
struct arm_mhuv2 *mhuv2;
struct device *dev = &adev->dev;
void __iomem *rx_base, *tx_base;
const struct device_node *np = dev->of_node;
unsigned int pchans;
/* Allocate memory for device */
mhuv2 = devm_kzalloc(dev, sizeof(*mhuv2), GFP_KERNEL);
if (!mhuv2)
return -ENOMEM;
tx_base = of_iomap((struct device_node *)np, 0);
if (!tx_base) {
dev_err(dev, "failed to map tx registers\n");
iounmap(rx_base);
return -ENOMEM;
}
rx_base = of_iomap((struct device_node *)np, 1);
if (!rx_base) {
dev_err(dev, "failed to map rx registers\n");
return -ENOMEM;
}
pchans = readl_relaxed(tx_base + MHU_V2_REG_MSG_NO_CAP_OFS);
if (pchans == 0 || pchans > MHU_V2_CHANS || pchans % 2) {
dev_err(dev, "invalid number of channels %d\n", pchans);
iounmap(rx_base);
iounmap(tx_base);
return -EINVAL;
}
for (i = 0; i < pchans/2; i++) {
mhuv2->chan[i].con_priv = &mhuv2->mlink[i];
mhuv2->mlink[i].irq = adev->irq[i];
mhuv2->mlink[i].rx_reg = rx_base + i*0x4;
mhuv2->mlink[i].tx_reg = tx_base + i*0x4;
}
mhuv2->base = tx_base;
mhuv2->mbox.dev = dev;
mhuv2->mbox.chans = &mhuv2->chan[0];
mhuv2->mbox.num_chans = pchans;
mhuv2->mbox.ops = &mhuv2_ops;
mhuv2->mbox.txdone_irq = false;
mhuv2->mbox.txdone_poll = true;
mhuv2->mbox.txpoll_period = 1;
amba_set_drvdata(adev, mhuv2);
err = mbox_controller_register(&mhuv2->mbox);
if (err) {
dev_err(dev, "failed to register mailboxes %d\n", err);
iounmap(rx_base);
iounmap(tx_base);
return err;
}
dev_info(dev, "ARM MHUv2 Mailbox driver registered\n");
return 0;
}
static int mhuv2_remove(struct amba_device *adev)
{
struct arm_mhuv2 *mhuv2 = amba_get_drvdata(adev);
mbox_controller_unregister(&mhuv2->mbox);
return 0;
}
static struct amba_id mhuv2_ids[] = {
{
.id = 0x4b0d1,
.mask = 0xfffff,
},
{
.id = 0xbb0d1,
.mask = 0xfffff,
},
{ 0, 0 },
};
MODULE_DEVICE_TABLE(amba, mhuv2_ids);
static struct amba_driver arm_mhuv2_driver = {
.drv = {
.name = "mhuv2",
},
.id_table = mhuv2_ids,
.probe = mhuv2_probe,
.remove = mhuv2_remove,
};
module_amba_driver(arm_mhuv2_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("ARM MHUv2 Driver");
MODULE_AUTHOR("Samarth Parikh <samarthp@ymail.com>");
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