linux/linux-5.4.31/drivers/mailbox/armada-37xx-rwtm-mailbox.c

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2024-01-30 10:43:28 +00:00
// SPDX-License-Identifier: GPL-2.0+
/*
* rWTM BIU Mailbox driver for Armada 37xx
*
* Author: Marek Behun <marek.behun@nic.cz>
*/
#include <linux/device.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/platform_device.h>
#include <linux/armada-37xx-rwtm-mailbox.h>
#define DRIVER_NAME "armada-37xx-rwtm-mailbox"
/* relative to rWTM BIU Mailbox Registers */
#define RWTM_MBOX_PARAM(i) (0x0 + ((i) << 2))
#define RWTM_MBOX_COMMAND 0x40
#define RWTM_MBOX_RETURN_STATUS 0x80
#define RWTM_MBOX_STATUS(i) (0x84 + ((i) << 2))
#define RWTM_MBOX_FIFO_STATUS 0xc4
#define FIFO_STS_RDY 0x100
#define FIFO_STS_CNTR_MASK 0x7
#define FIFO_STS_CNTR_MAX 4
#define RWTM_HOST_INT_RESET 0xc8
#define RWTM_HOST_INT_MASK 0xcc
#define SP_CMD_COMPLETE BIT(0)
#define SP_CMD_QUEUE_FULL_ACCESS BIT(17)
#define SP_CMD_QUEUE_FULL BIT(18)
struct a37xx_mbox {
struct device *dev;
struct mbox_controller controller;
void __iomem *base;
int irq;
};
static void a37xx_mbox_receive(struct mbox_chan *chan)
{
struct a37xx_mbox *mbox = chan->con_priv;
struct armada_37xx_rwtm_rx_msg rx_msg;
int i;
rx_msg.retval = readl(mbox->base + RWTM_MBOX_RETURN_STATUS);
for (i = 0; i < 16; ++i)
rx_msg.status[i] = readl(mbox->base + RWTM_MBOX_STATUS(i));
mbox_chan_received_data(chan, &rx_msg);
}
static irqreturn_t a37xx_mbox_irq_handler(int irq, void *data)
{
struct mbox_chan *chan = data;
struct a37xx_mbox *mbox = chan->con_priv;
u32 reg;
reg = readl(mbox->base + RWTM_HOST_INT_RESET);
if (reg & SP_CMD_COMPLETE)
a37xx_mbox_receive(chan);
if (reg & (SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL))
dev_err(mbox->dev, "Secure processor command queue full\n");
writel(reg, mbox->base + RWTM_HOST_INT_RESET);
if (reg)
mbox_chan_txdone(chan, 0);
return reg ? IRQ_HANDLED : IRQ_NONE;
}
static int a37xx_mbox_send_data(struct mbox_chan *chan, void *data)
{
struct a37xx_mbox *mbox = chan->con_priv;
struct armada_37xx_rwtm_tx_msg *msg = data;
int i;
u32 reg;
if (!data)
return -EINVAL;
reg = readl(mbox->base + RWTM_MBOX_FIFO_STATUS);
if (!(reg & FIFO_STS_RDY))
dev_warn(mbox->dev, "Secure processor not ready\n");
if ((reg & FIFO_STS_CNTR_MASK) >= FIFO_STS_CNTR_MAX) {
dev_err(mbox->dev, "Secure processor command queue full\n");
return -EBUSY;
}
for (i = 0; i < 16; ++i)
writel(msg->args[i], mbox->base + RWTM_MBOX_PARAM(i));
writel(msg->command, mbox->base + RWTM_MBOX_COMMAND);
return 0;
}
static int a37xx_mbox_startup(struct mbox_chan *chan)
{
struct a37xx_mbox *mbox = chan->con_priv;
u32 reg;
int ret;
ret = devm_request_irq(mbox->dev, mbox->irq, a37xx_mbox_irq_handler, 0,
DRIVER_NAME, chan);
if (ret < 0) {
dev_err(mbox->dev, "Cannot request irq\n");
return ret;
}
/* enable IRQ generation */
reg = readl(mbox->base + RWTM_HOST_INT_MASK);
reg &= ~(SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL);
writel(reg, mbox->base + RWTM_HOST_INT_MASK);
return 0;
}
static void a37xx_mbox_shutdown(struct mbox_chan *chan)
{
u32 reg;
struct a37xx_mbox *mbox = chan->con_priv;
/* disable interrupt generation */
reg = readl(mbox->base + RWTM_HOST_INT_MASK);
reg |= SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL;
writel(reg, mbox->base + RWTM_HOST_INT_MASK);
devm_free_irq(mbox->dev, mbox->irq, chan);
}
static const struct mbox_chan_ops a37xx_mbox_ops = {
.send_data = a37xx_mbox_send_data,
.startup = a37xx_mbox_startup,
.shutdown = a37xx_mbox_shutdown,
};
static int armada_37xx_mbox_probe(struct platform_device *pdev)
{
struct a37xx_mbox *mbox;
struct resource *regs;
struct mbox_chan *chans;
int ret;
mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
if (!mbox)
return -ENOMEM;
/* Allocated one channel */
chans = devm_kzalloc(&pdev->dev, sizeof(*chans), GFP_KERNEL);
if (!chans)
return -ENOMEM;
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mbox->base = devm_ioremap_resource(&pdev->dev, regs);
if (IS_ERR(mbox->base)) {
dev_err(&pdev->dev, "ioremap failed\n");
return PTR_ERR(mbox->base);
}
mbox->irq = platform_get_irq(pdev, 0);
if (mbox->irq < 0) {
dev_err(&pdev->dev, "Cannot get irq\n");
return mbox->irq;
}
mbox->dev = &pdev->dev;
/* Hardware supports only one channel. */
chans[0].con_priv = mbox;
mbox->controller.dev = mbox->dev;
mbox->controller.num_chans = 1;
mbox->controller.chans = chans;
mbox->controller.ops = &a37xx_mbox_ops;
mbox->controller.txdone_irq = true;
ret = devm_mbox_controller_register(mbox->dev, &mbox->controller);
if (ret) {
dev_err(&pdev->dev, "Could not register mailbox controller\n");
return ret;
}
platform_set_drvdata(pdev, mbox);
return ret;
}
static const struct of_device_id armada_37xx_mbox_match[] = {
{ .compatible = "marvell,armada-3700-rwtm-mailbox" },
{ },
};
MODULE_DEVICE_TABLE(of, armada_37xx_mbox_match);
static struct platform_driver armada_37xx_mbox_driver = {
.probe = armada_37xx_mbox_probe,
.driver = {
.name = DRIVER_NAME,
.of_match_table = armada_37xx_mbox_match,
},
};
module_platform_driver(armada_37xx_mbox_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("rWTM BIU Mailbox driver for Armada 37xx");
MODULE_AUTHOR("Marek Behun <marek.behun@nic.cz>");