1 // SPDX-License-Identifier: GPL-2.0
4  *  Copyright (C) 2013-2014 Lubomir Rintel
8  *  - arch/arm/mach-bcm2708/vcio.c file written by Gray Girling that was
9  *    obtained from branch "rpi-3.6.y" of git://github.com/raspberrypi/
11  *  - drivers/mailbox/bcm2835-ipc.c by Lubomir Rintel at
12  *    https://github.com/hackerspace/rpi-linux/blob/lr-raspberry-pi/drivers/
13  *    mailbox/bcm2835-ipc.c
14  *  - documentation available on the following web site:
15  *    https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface
19 #include <linux/dma-mapping.h>
38  * BCM2835-ARM-Peripherals.pdf section 1.3 for an explanation about
63 	return container_of(link->mbox, struct bcm2835_mbox, controller);  in bcm2835_link_mbox()
68 	struct bcm2835_mbox *mbox = dev_id;  in bcm2835_mbox_irq()  local
69 	struct device *dev = mbox->controller.dev;  in bcm2835_mbox_irq()
70 	struct mbox_chan *link = &mbox->controller.chans[0];  in bcm2835_mbox_irq()
72 	while (!(readl(mbox->regs + MAIL0_STA) & ARM_MS_EMPTY)) {  in bcm2835_mbox_irq()
73 		u32 msg = readl(mbox->regs + MAIL0_RD);  in bcm2835_mbox_irq()
82 	struct bcm2835_mbox *mbox = bcm2835_link_mbox(link);  in bcm2835_send_data()  local
85 	spin_lock(&mbox->lock);  in bcm2835_send_data()
86 	writel(msg, mbox->regs + MAIL1_WRT);  in bcm2835_send_data()
87 	dev_dbg(mbox->controller.dev, "Request 0x%08X\n", msg);  in bcm2835_send_data()
88 	spin_unlock(&mbox->lock);  in bcm2835_send_data()
94 	struct bcm2835_mbox *mbox = bcm2835_link_mbox(link);  in bcm2835_startup()  local
97 	writel(ARM_MC_IHAVEDATAIRQEN, mbox->regs + MAIL0_CNF);  in bcm2835_startup()
104 	struct bcm2835_mbox *mbox = bcm2835_link_mbox(link);  in bcm2835_shutdown()  local
106 	writel(0, mbox->regs + MAIL0_CNF);  in bcm2835_shutdown()
111 	struct bcm2835_mbox *mbox = bcm2835_link_mbox(link);  in bcm2835_last_tx_done()  local
114 	spin_lock(&mbox->lock);  in bcm2835_last_tx_done()
115 	ret = !(readl(mbox->regs + MAIL1_STA) & ARM_MS_FULL);  in bcm2835_last_tx_done()
116 	spin_unlock(&mbox->lock);  in bcm2835_last_tx_done()
127 static struct mbox_chan *bcm2835_mbox_index_xlate(struct mbox_controller *mbox,  in bcm2835_mbox_index_xlate()  argument
130 	if (sp->args_count != 0)  in bcm2835_mbox_index_xlate()
131 		return ERR_PTR(-EINVAL);  in bcm2835_mbox_index_xlate()
133 	return &mbox->chans[0];  in bcm2835_mbox_index_xlate()
138 	struct device *dev = &pdev->dev;  in bcm2835_mbox_probe()
140 	struct bcm2835_mbox *mbox;  in bcm2835_mbox_probe()  local
142 	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);  in bcm2835_mbox_probe()
143 	if (mbox == NULL)  in bcm2835_mbox_probe()
144 		return -ENOMEM;  in bcm2835_mbox_probe()
145 	spin_lock_init(&mbox->lock);  in bcm2835_mbox_probe()
147 	ret = devm_request_irq(dev, irq_of_parse_and_map(dev->of_node, 0),  in bcm2835_mbox_probe()
149 			       mbox);  in bcm2835_mbox_probe()
153 		return -ENODEV;  in bcm2835_mbox_probe()
156 	mbox->regs = devm_platform_ioremap_resource(pdev, 0);  in bcm2835_mbox_probe()
157 	if (IS_ERR(mbox->regs)) {  in bcm2835_mbox_probe()
158 		ret = PTR_ERR(mbox->regs);  in bcm2835_mbox_probe()
162 	mbox->controller.txdone_poll = true;  in bcm2835_mbox_probe()
163 	mbox->controller.txpoll_period = 5;  in bcm2835_mbox_probe()
164 	mbox->controller.ops = &bcm2835_mbox_chan_ops;  in bcm2835_mbox_probe()
165 	mbox->controller.of_xlate = &bcm2835_mbox_index_xlate;  in bcm2835_mbox_probe()
166 	mbox->controller.dev = dev;  in bcm2835_mbox_probe()
167 	mbox->controller.num_chans = 1;  in bcm2835_mbox_probe()
168 	mbox->controller.chans = devm_kzalloc(dev,  in bcm2835_mbox_probe()
169 		sizeof(*mbox->controller.chans), GFP_KERNEL);  in bcm2835_mbox_probe()
170 	if (!mbox->controller.chans)  in bcm2835_mbox_probe()
171 		return -ENOMEM;  in bcm2835_mbox_probe()
173 	ret = devm_mbox_controller_register(dev, &mbox->controller);  in bcm2835_mbox_probe()
177 	platform_set_drvdata(pdev, mbox);  in bcm2835_mbox_probe()
184 	{ .compatible = "brcm,bcm2835-mbox", },
191 		.name = "bcm2835-mbox",
199 MODULE_DESCRIPTION("BCM2835 mailbox IPC driver");