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// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2020 Maxime Ripard <maxime@cerno.tech> */
#include <linux/device.h>
#include <linux/dma-map-ops.h>
#include <linux/init.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/platform_device.h>
static const char * const sunxi_mbus_devices[] = {
/*
* The display engine virtual devices are not strictly speaking
* connected to the MBUS, but since DRM will perform all the
* memory allocations and DMA operations through that device, we
* need to have the quirk on those devices too.
*/
"allwinner,sun4i-a10-display-engine",
"allwinner,sun5i-a10s-display-engine",
"allwinner,sun5i-a13-display-engine",
"allwinner,sun6i-a31-display-engine",
"allwinner,sun6i-a31s-display-engine",
"allwinner,sun7i-a20-display-engine",
"allwinner,sun8i-a23-display-engine",
"allwinner,sun8i-a33-display-engine",
"allwinner,sun8i-a83t-display-engine",
"allwinner,sun8i-h3-display-engine",
"allwinner,sun8i-r40-display-engine",
"allwinner,sun8i-v3s-display-engine",
"allwinner,sun9i-a80-display-engine",
"allwinner,sun50i-a64-display-engine",
/*
* And now we have the regular devices connected to the MBUS
* (that we know of).
*/
"allwinner,sun4i-a10-csi1",
"allwinner,sun4i-a10-display-backend",
"allwinner,sun4i-a10-display-frontend",
"allwinner,sun4i-a10-video-engine",
"allwinner,sun5i-a13-display-backend",
"allwinner,sun5i-a13-video-engine",
"allwinner,sun6i-a31-csi",
"allwinner,sun6i-a31-display-backend",
"allwinner,sun7i-a20-csi0",
"allwinner,sun7i-a20-display-backend",
"allwinner,sun7i-a20-display-frontend",
"allwinner,sun7i-a20-video-engine",
"allwinner,sun8i-a23-display-backend",
"allwinner,sun8i-a23-display-frontend",
"allwinner,sun8i-a33-display-backend",
"allwinner,sun8i-a33-display-frontend",
"allwinner,sun8i-a33-video-engine",
"allwinner,sun8i-a83t-csi",
"allwinner,sun8i-h3-csi",
"allwinner,sun8i-h3-video-engine",
"allwinner,sun8i-v3s-csi",
"allwinner,sun9i-a80-display-backend",
"allwinner,sun50i-a64-csi",
"allwinner,sun50i-a64-video-engine",
"allwinner,sun50i-h5-video-engine",
NULL,
};
static int sunxi_mbus_notifier(struct notifier_block *nb,
unsigned long event, void *__dev)
{
struct device *dev = __dev;
int ret;
if (event != BUS_NOTIFY_ADD_DEVICE)
return NOTIFY_DONE;
/*
* Only the devices that need a large memory bandwidth do DMA
* directly over the memory bus (called MBUS), instead of going
* through the regular system bus.
*/
if (!of_device_compatible_match(dev->of_node, sunxi_mbus_devices))
return NOTIFY_DONE;
/*
* Devices with an interconnects property have the MBUS
* relationship described in their DT and dealt with by
* of_dma_configure, so we can just skip them.
*
* Older DTs or SoCs who are not clearly understood need to set
* that DMA offset though.
*/
if (of_find_property(dev->of_node, "interconnects", NULL))
return NOTIFY_DONE;
ret = dma_direct_set_offset(dev, PHYS_OFFSET, 0, SZ_4G);
if (ret)
dev_err(dev, "Couldn't setup our DMA offset: %d\n", ret);
return NOTIFY_DONE;
}
static struct notifier_block sunxi_mbus_nb = {
.notifier_call = sunxi_mbus_notifier,
};
static const char * const sunxi_mbus_platforms[] __initconst = {
"allwinner,sun4i-a10",
"allwinner,sun5i-a10s",
"allwinner,sun5i-a13",
"allwinner,sun6i-a31",
"allwinner,sun7i-a20",
"allwinner,sun8i-a23",
"allwinner,sun8i-a33",
"allwinner,sun8i-a83t",
"allwinner,sun8i-h3",
"allwinner,sun8i-r40",
"allwinner,sun8i-v3",
"allwinner,sun8i-v3s",
"allwinner,sun9i-a80",
"allwinner,sun50i-a64",
"allwinner,sun50i-h5",
"nextthing,gr8",
NULL,
};
static int __init sunxi_mbus_init(void)
{
if (!of_device_compatible_match(of_root, sunxi_mbus_platforms))
return 0;
bus_register_notifier(&platform_bus_type, &sunxi_mbus_nb);
return 0;
}
arch_initcall(sunxi_mbus_init);
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