linux/drivers/mailbox/arm_mhu.c
Sudeep Holla ab99e237a4 mailbox: arm_mhu: Match only if compatible is "arm,mhu"
Since we will be soon adding a separate driver based on this ARM MHU
driver to support doorbell mode, let us add explicit check to match
the default compatible for this driver. This is needed as the probe
and match reuses the AMBA device ids currently and don't have any
explicit compatible check.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2020-10-12 21:10:34 -05:00

178 lines
3.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
* Copyright (C) 2015 Linaro Ltd.
* Author: Jassi Brar <jaswinder.singh@linaro.org>
*/
#include <linux/amba/bus.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mailbox_controller.h>
#include <linux/module.h>
#define INTR_STAT_OFS 0x0
#define INTR_SET_OFS 0x8
#define INTR_CLR_OFS 0x10
#define MHU_LP_OFFSET 0x0
#define MHU_HP_OFFSET 0x20
#define MHU_SEC_OFFSET 0x200
#define TX_REG_OFFSET 0x100
#define MHU_CHANS 3
struct mhu_link {
unsigned irq;
void __iomem *tx_reg;
void __iomem *rx_reg;
};
struct arm_mhu {
void __iomem *base;
struct mhu_link mlink[MHU_CHANS];
struct mbox_chan chan[MHU_CHANS];
struct mbox_controller mbox;
};
static irqreturn_t mhu_rx_interrupt(int irq, void *p)
{
struct mbox_chan *chan = p;
struct mhu_link *mlink = chan->con_priv;
u32 val;
val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS);
if (!val)
return IRQ_NONE;
mbox_chan_received_data(chan, (void *)&val);
writel_relaxed(val, mlink->rx_reg + INTR_CLR_OFS);
return IRQ_HANDLED;
}
static bool mhu_last_tx_done(struct mbox_chan *chan)
{
struct mhu_link *mlink = chan->con_priv;
u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
return (val == 0);
}
static int mhu_send_data(struct mbox_chan *chan, void *data)
{
struct mhu_link *mlink = chan->con_priv;
u32 *arg = data;
writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS);
return 0;
}
static int mhu_startup(struct mbox_chan *chan)
{
struct mhu_link *mlink = chan->con_priv;
u32 val;
int ret;
val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS);
ret = request_irq(mlink->irq, mhu_rx_interrupt,
IRQF_SHARED, "mhu_link", chan);
if (ret) {
dev_err(chan->mbox->dev,
"Unable to acquire IRQ %d\n", mlink->irq);
return ret;
}
return 0;
}
static void mhu_shutdown(struct mbox_chan *chan)
{
struct mhu_link *mlink = chan->con_priv;
free_irq(mlink->irq, chan);
}
static const struct mbox_chan_ops mhu_ops = {
.send_data = mhu_send_data,
.startup = mhu_startup,
.shutdown = mhu_shutdown,
.last_tx_done = mhu_last_tx_done,
};
static int mhu_probe(struct amba_device *adev, const struct amba_id *id)
{
int i, err;
struct arm_mhu *mhu;
struct device *dev = &adev->dev;
int mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET};
if (!of_device_is_compatible(dev->of_node, "arm,mhu"))
return -ENODEV;
/* Allocate memory for device */
mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
if (!mhu)
return -ENOMEM;
mhu->base = devm_ioremap_resource(dev, &adev->res);
if (IS_ERR(mhu->base)) {
dev_err(dev, "ioremap failed\n");
return PTR_ERR(mhu->base);
}
for (i = 0; i < MHU_CHANS; i++) {
mhu->chan[i].con_priv = &mhu->mlink[i];
mhu->mlink[i].irq = adev->irq[i];
mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i];
mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;
}
mhu->mbox.dev = dev;
mhu->mbox.chans = &mhu->chan[0];
mhu->mbox.num_chans = MHU_CHANS;
mhu->mbox.ops = &mhu_ops;
mhu->mbox.txdone_irq = false;
mhu->mbox.txdone_poll = true;
mhu->mbox.txpoll_period = 1;
amba_set_drvdata(adev, mhu);
err = devm_mbox_controller_register(dev, &mhu->mbox);
if (err) {
dev_err(dev, "Failed to register mailboxes %d\n", err);
return err;
}
dev_info(dev, "ARM MHU Mailbox registered\n");
return 0;
}
static struct amba_id mhu_ids[] = {
{
.id = 0x1bb098,
.mask = 0xffffff,
},
{ 0, 0 },
};
MODULE_DEVICE_TABLE(amba, mhu_ids);
static struct amba_driver arm_mhu_driver = {
.drv = {
.name = "mhu",
},
.id_table = mhu_ids,
.probe = mhu_probe,
};
module_amba_driver(arm_mhu_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("ARM MHU Driver");
MODULE_AUTHOR("Jassi Brar <jassisinghbrar@gmail.com>");