linux/drivers/mailbox/mailbox-mpfs.c
Conor Dooley 83d7b15608 mbox: add polarfire soc system controller mailbox
This driver adds support for the single mailbox channel of the MSS
system controller on the Microchip PolarFire SoC.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2021-06-26 12:06:48 -05:00

252 lines
6.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Microchip PolarFire SoC (MPFS) system controller/mailbox controller driver
*
* Copyright (c) 2020 Microchip Corporation. All rights reserved.
*
* Author: Conor Dooley <conor.dooley@microchip.com>
*
*/
#include <linux/io.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/mailbox_controller.h>
#include <soc/microchip/mpfs.h>
#define SERVICES_CR_OFFSET 0x50u
#define SERVICES_SR_OFFSET 0x54u
#define MAILBOX_REG_OFFSET 0x800u
#define MSS_SYS_MAILBOX_DATA_OFFSET 0u
#define SCB_MASK_WIDTH 16u
/* SCBCTRL service control register */
#define SCB_CTRL_REQ (0)
#define SCB_CTRL_REQ_MASK BIT(SCB_CTRL_REQ)
#define SCB_CTRL_BUSY (1)
#define SCB_CTRL_BUSY_MASK BIT(SCB_CTRL_BUSY)
#define SCB_CTRL_ABORT (2)
#define SCB_CTRL_ABORT_MASK BIT(SCB_CTRL_ABORT)
#define SCB_CTRL_NOTIFY (3)
#define SCB_CTRL_NOTIFY_MASK BIT(SCB_CTRL_NOTIFY)
#define SCB_CTRL_POS (16)
#define SCB_CTRL_MASK GENMASK_ULL(SCB_CTRL_POS + SCB_MASK_WIDTH, SCB_CTRL_POS)
/* SCBCTRL service status register */
#define SCB_STATUS_REQ (0)
#define SCB_STATUS_REQ_MASK BIT(SCB_STATUS_REQ)
#define SCB_STATUS_BUSY (1)
#define SCB_STATUS_BUSY_MASK BIT(SCB_STATUS_BUSY)
#define SCB_STATUS_ABORT (2)
#define SCB_STATUS_ABORT_MASK BIT(SCB_STATUS_ABORT)
#define SCB_STATUS_NOTIFY (3)
#define SCB_STATUS_NOTIFY_MASK BIT(SCB_STATUS_NOTIFY)
#define SCB_STATUS_POS (16)
#define SCB_STATUS_MASK GENMASK_ULL(SCB_STATUS_POS + SCB_MASK_WIDTH, SCB_STATUS_POS)
struct mpfs_mbox {
struct mbox_controller controller;
struct device *dev;
int irq;
void __iomem *mbox_base;
void __iomem *int_reg;
struct mbox_chan chans[1];
struct mpfs_mss_response *response;
u16 resp_offset;
};
static bool mpfs_mbox_busy(struct mpfs_mbox *mbox)
{
u32 status;
status = readl_relaxed(mbox->mbox_base + SERVICES_SR_OFFSET);
return status & SCB_STATUS_BUSY_MASK;
}
static int mpfs_mbox_send_data(struct mbox_chan *chan, void *data)
{
struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
struct mpfs_mss_msg *msg = data;
u32 tx_trigger;
u16 opt_sel;
u32 val = 0u;
mbox->response = msg->response;
mbox->resp_offset = msg->resp_offset;
if (mpfs_mbox_busy(mbox))
return -EBUSY;
if (msg->cmd_data_size) {
u32 index;
u8 extra_bits = msg->cmd_data_size & 3;
u32 *word_buf = (u32 *)msg->cmd_data;
for (index = 0; index < (msg->cmd_data_size / 4); index++)
writel_relaxed(word_buf[index],
mbox->mbox_base + MAILBOX_REG_OFFSET + index * 0x4);
if (extra_bits) {
u8 i;
u8 byte_off = ALIGN_DOWN(msg->cmd_data_size, 4);
u8 *byte_buf = msg->cmd_data + byte_off;
val = readl_relaxed(mbox->mbox_base +
MAILBOX_REG_OFFSET + index * 0x4);
for (i = 0u; i < extra_bits; i++) {
val &= ~(0xffu << (i * 8u));
val |= (byte_buf[i] << (i * 8u));
}
writel_relaxed(val,
mbox->mbox_base + MAILBOX_REG_OFFSET + index * 0x4);
}
}
opt_sel = ((msg->mbox_offset << 7u) | (msg->cmd_opcode & 0x7fu));
tx_trigger = (opt_sel << SCB_CTRL_POS) & SCB_CTRL_MASK;
tx_trigger |= SCB_CTRL_REQ_MASK | SCB_STATUS_NOTIFY_MASK;
writel_relaxed(tx_trigger, mbox->mbox_base + SERVICES_CR_OFFSET);
return 0;
}
static void mpfs_mbox_rx_data(struct mbox_chan *chan)
{
struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
struct mpfs_mss_response *response = mbox->response;
u16 num_words = ALIGN((response->resp_size), (4)) / 4U;
u32 i;
if (!response->resp_msg) {
dev_err(mbox->dev, "failed to assign memory for response %d\n", -ENOMEM);
return;
}
if (!mpfs_mbox_busy(mbox)) {
for (i = 0; i < num_words; i++) {
response->resp_msg[i] =
readl_relaxed(mbox->mbox_base + MAILBOX_REG_OFFSET
+ mbox->resp_offset + i * 0x4);
}
}
mbox_chan_received_data(chan, response);
}
static irqreturn_t mpfs_mbox_inbox_isr(int irq, void *data)
{
struct mbox_chan *chan = data;
struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
writel_relaxed(0, mbox->int_reg);
mpfs_mbox_rx_data(chan);
mbox_chan_txdone(chan, 0);
return IRQ_HANDLED;
}
static int mpfs_mbox_startup(struct mbox_chan *chan)
{
struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
int ret = 0;
if (!mbox)
return -EINVAL;
ret = devm_request_irq(mbox->dev, mbox->irq, mpfs_mbox_inbox_isr, 0, "mpfs-mailbox", chan);
if (ret)
dev_err(mbox->dev, "failed to register mailbox interrupt:%d\n", ret);
return ret;
}
static void mpfs_mbox_shutdown(struct mbox_chan *chan)
{
struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
devm_free_irq(mbox->dev, mbox->irq, chan);
}
static const struct mbox_chan_ops mpfs_mbox_ops = {
.send_data = mpfs_mbox_send_data,
.startup = mpfs_mbox_startup,
.shutdown = mpfs_mbox_shutdown,
};
static int mpfs_mbox_probe(struct platform_device *pdev)
{
struct mpfs_mbox *mbox;
struct resource *regs;
int ret;
mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
if (!mbox)
return -ENOMEM;
mbox->mbox_base = devm_platform_get_and_ioremap_resource(pdev, 0, &regs);
if (IS_ERR(mbox->mbox_base))
return PTR_ERR(mbox->mbox_base);
mbox->int_reg = devm_platform_get_and_ioremap_resource(pdev, 1, &regs);
if (IS_ERR(mbox->int_reg))
return PTR_ERR(mbox->int_reg);
mbox->irq = platform_get_irq(pdev, 0);
if (mbox->irq < 0)
return mbox->irq;
mbox->dev = &pdev->dev;
mbox->chans[0].con_priv = mbox;
mbox->controller.dev = mbox->dev;
mbox->controller.num_chans = 1;
mbox->controller.chans = mbox->chans;
mbox->controller.ops = &mpfs_mbox_ops;
mbox->controller.txdone_irq = true;
ret = devm_mbox_controller_register(&pdev->dev, &mbox->controller);
if (ret) {
dev_err(&pdev->dev, "Registering MPFS mailbox controller failed\n");
return ret;
}
dev_info(&pdev->dev, "Registered MPFS mailbox controller driver\n");
return 0;
}
static const struct of_device_id mpfs_mbox_of_match[] = {
{.compatible = "microchip,polarfire-soc-mailbox", },
{},
};
MODULE_DEVICE_TABLE(of, mpfs_mbox_of_match);
static struct platform_driver mpfs_mbox_driver = {
.driver = {
.name = "mpfs-mailbox",
.of_match_table = mpfs_mbox_of_match,
},
.probe = mpfs_mbox_probe,
};
module_platform_driver(mpfs_mbox_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
MODULE_DESCRIPTION("MPFS mailbox controller driver");