Commit ae524eb7 authored by Jammy Huang's avatar Jammy Huang Committed by Jassi Brar
Browse files

mailbox: aspeed: add mailbox driver for AST27XX series SoC 



Add mailbox controller driver for AST27XX SoCs, which provides
independent tx/rx mailbox between different processors. There are 4
channels for each tx/rx mailbox and each channel has an 32-byte FIFO.

Signed-off-by: default avatarJammy Huang <jammy_huang@aspeedtech.com>
Reviewed-by: default avatarAndrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: default avatarJassi Brar <jassisinghbrar@gmail.com>
parent 7d33dd2d

drivers/mailbox/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -36,6 +36,15 @@ config ARM_MHU_V3 
	  that provides different means of transports: supported extensions

	  will be discovered and possibly managed at probe-time.



config AST2700_MBOX

	tristate "ASPEED AST2700 IPC driver"

	depends on ARCH_ASPEED || COMPILE_TEST

	help

	  Mailbox driver implementation for ASPEED AST27XX SoCs. This driver

	  can be used to send message between different processors in SoC.

	  The driver provides mailbox support for sending interrupts to the

	  clients. Say Y here if you want to build this driver.



config CV1800_MBOX

	tristate "cv1800 mailbox"

	depends on ARCH_SOPHGO || COMPILE_TEST

drivers/mailbox/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -11,6 +11,8 @@ obj-$(CONFIG_ARM_MHU_V2) += arm_mhuv2.o 


obj-$(CONFIG_ARM_MHU_V3)	+= arm_mhuv3.o



obj-$(CONFIG_AST2700_MBOX)	+= ast2700-mailbox.o



obj-$(CONFIG_CV1800_MBOX)	+= cv1800-mailbox.o



obj-$(CONFIG_EXYNOS_MBOX)	+= exynos-mailbox.o

drivers/mailbox/ast2700-mailbox.c

0 → 100644
+235 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright Aspeed Technology Inc. (C) 2025. All rights reserved

 */



#include <linux/interrupt.h>

#include <linux/io.h>

#include <linux/iopoll.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/slab.h>



/* Each bit in the register represents an IPC ID */

#define IPCR_TX_TRIG		0x00

#define IPCR_ENABLE		0x04

#define IPCR_STATUS		0x08

#define  RX_IRQ(n)		BIT(n)

#define  RX_IRQ_MASK		0xf

#define IPCR_DATA		0x10



struct ast2700_mbox_data {

	u8 num_chans;

	u8 msg_size;

};



struct ast2700_mbox {

	struct mbox_controller mbox;

	u8 msg_size;

	void __iomem *tx_regs;

	void __iomem *rx_regs;

	spinlock_t lock;

};



static inline int ch_num(struct mbox_chan *chan)

{

	return chan - chan->mbox->chans;

}



static inline bool ast2700_mbox_tx_done(struct ast2700_mbox *mb, int idx)

{

	return !(readl(mb->tx_regs + IPCR_STATUS) & BIT(idx));

}



static irqreturn_t ast2700_mbox_irq(int irq, void *p)

{

	struct ast2700_mbox *mb = p;

	void __iomem *data_reg;

	int num_words = mb->msg_size / sizeof(u32);

	u32 *word_data;

	u32 status;

	int n, i;



	/* Only examine channels that are currently enabled. */

	status = readl(mb->rx_regs + IPCR_ENABLE) &

		 readl(mb->rx_regs + IPCR_STATUS);



	if (!(status & RX_IRQ_MASK))

		return IRQ_NONE;



	for (n = 0; n < mb->mbox.num_chans; ++n) {

		struct mbox_chan *chan = &mb->mbox.chans[n];



		if (!(status & RX_IRQ(n)))

			continue;



		data_reg = mb->rx_regs + IPCR_DATA + mb->msg_size * n;

		word_data = chan->con_priv;

		/* Read the message data */

		for (i = 0; i < num_words; i++)

			word_data[i] = readl(data_reg + i * sizeof(u32));



		mbox_chan_received_data(chan, chan->con_priv);



		/* The IRQ can be cleared only once the FIFO is empty. */

		writel(RX_IRQ(n), mb->rx_regs + IPCR_STATUS);

	}



	return IRQ_HANDLED;

}



static int ast2700_mbox_send_data(struct mbox_chan *chan, void *data)

{

	struct ast2700_mbox *mb = dev_get_drvdata(chan->mbox->dev);

	int idx = ch_num(chan);

	void __iomem *data_reg = mb->tx_regs + IPCR_DATA + mb->msg_size * idx;

	u32 *word_data = data;

	int num_words = mb->msg_size / sizeof(u32);

	int i;



	if (!(readl(mb->tx_regs + IPCR_ENABLE) & BIT(idx))) {

		dev_warn(mb->mbox.dev, "%s: Ch-%d not enabled yet\n", __func__, idx);

		return -ENODEV;

	}



	if (!(ast2700_mbox_tx_done(mb, idx))) {

		dev_warn(mb->mbox.dev, "%s: Ch-%d last data has not finished\n", __func__, idx);

		return -EBUSY;

	}



	/* Write the message data */

	for (i = 0 ; i < num_words; i++)

		writel(word_data[i], data_reg + i * sizeof(u32));



	writel(BIT(idx), mb->tx_regs + IPCR_TX_TRIG);

	dev_dbg(mb->mbox.dev, "%s: Ch-%d sent\n", __func__, idx);



	return 0;

}



static int ast2700_mbox_startup(struct mbox_chan *chan)

{

	struct ast2700_mbox *mb = dev_get_drvdata(chan->mbox->dev);

	int idx = ch_num(chan);

	void __iomem *reg = mb->rx_regs + IPCR_ENABLE;

	unsigned long flags;



	spin_lock_irqsave(&mb->lock, flags);

	writel(readl(reg) | BIT(idx), reg);

	spin_unlock_irqrestore(&mb->lock, flags);



	return 0;

}



static void ast2700_mbox_shutdown(struct mbox_chan *chan)

{

	struct ast2700_mbox *mb = dev_get_drvdata(chan->mbox->dev);

	int idx = ch_num(chan);

	void __iomem *reg = mb->rx_regs + IPCR_ENABLE;

	unsigned long flags;



	spin_lock_irqsave(&mb->lock, flags);

	writel(readl(reg) & ~BIT(idx), reg);

	spin_unlock_irqrestore(&mb->lock, flags);

}



static bool ast2700_mbox_last_tx_done(struct mbox_chan *chan)

{

	struct ast2700_mbox *mb = dev_get_drvdata(chan->mbox->dev);

	int idx = ch_num(chan);



	return ast2700_mbox_tx_done(mb, idx);

}



static const struct mbox_chan_ops ast2700_mbox_chan_ops = {

	.send_data	= ast2700_mbox_send_data,

	.startup	= ast2700_mbox_startup,

	.shutdown	= ast2700_mbox_shutdown,

	.last_tx_done	= ast2700_mbox_last_tx_done,

};



static int ast2700_mbox_probe(struct platform_device *pdev)

{

	struct ast2700_mbox *mb;

	const struct ast2700_mbox_data *dev_data;

	struct device *dev = &pdev->dev;

	int irq, ret;



	if (!pdev->dev.of_node)

		return -ENODEV;



	dev_data = device_get_match_data(&pdev->dev);



	mb = devm_kzalloc(dev, sizeof(*mb), GFP_KERNEL);

	if (!mb)

		return -ENOMEM;



	mb->mbox.chans = devm_kcalloc(&pdev->dev, dev_data->num_chans,

				      sizeof(*mb->mbox.chans), GFP_KERNEL);

	if (!mb->mbox.chans)

		return -ENOMEM;



	/* con_priv of each channel is used to store the message received */

	for (int i = 0; i < dev_data->num_chans; i++) {

		mb->mbox.chans[i].con_priv = devm_kcalloc(dev, dev_data->msg_size,

							  sizeof(u8), GFP_KERNEL);

		if (!mb->mbox.chans[i].con_priv)

			return -ENOMEM;

	}



	platform_set_drvdata(pdev, mb);



	mb->tx_regs = devm_platform_ioremap_resource_byname(pdev, "tx");

	if (IS_ERR(mb->tx_regs))

		return PTR_ERR(mb->tx_regs);



	mb->rx_regs = devm_platform_ioremap_resource_byname(pdev, "rx");

	if (IS_ERR(mb->rx_regs))

		return PTR_ERR(mb->rx_regs);



	mb->msg_size = dev_data->msg_size;

	mb->mbox.dev = dev;

	mb->mbox.num_chans = dev_data->num_chans;

	mb->mbox.ops = &ast2700_mbox_chan_ops;

	mb->mbox.txdone_irq = false;

	mb->mbox.txdone_poll = true;

	mb->mbox.txpoll_period = 5;

	spin_lock_init(&mb->lock);



	irq = platform_get_irq(pdev, 0);

	if (irq < 0)

		return irq;



	ret = devm_request_irq(dev, irq, ast2700_mbox_irq, 0, dev_name(dev), mb);

	if (ret)

		return ret;



	return devm_mbox_controller_register(dev, &mb->mbox);

}



static const struct ast2700_mbox_data ast2700_dev_data = {

	.num_chans = 4,

	.msg_size = 0x20,

};



static const struct of_device_id ast2700_mbox_of_match[] = {

	{ .compatible = "aspeed,ast2700-mailbox", .data = &ast2700_dev_data },

	{}

};

MODULE_DEVICE_TABLE(of, ast2700_mbox_of_match);



static struct platform_driver ast2700_mbox_driver = {

	.driver = {

		.name = "ast2700-mailbox",

		.of_match_table = ast2700_mbox_of_match,

	},

	.probe = ast2700_mbox_probe,

};

module_platform_driver(ast2700_mbox_driver);



MODULE_AUTHOR("Jammy Huang <jammy_huang@aspeedtech.com>");

MODULE_DESCRIPTION("ASPEED AST2700 IPC driver");

MODULE_LICENSE("GPL");