linux/drivers/soc/sunxi/sunxi_mbus.c
Rob Herring a9c6a1fcc3 soc: sunxi: Use of_property_present() for testing DT property presence
It is preferred to use typed property access functions (i.e.
of_property_read_<type> functions) rather than low-level
of_get_property/of_find_property functions for reading properties. As
part of this, convert of_get_property/of_find_property calls to the
recently added of_property_present() helper when we just want to test
for presence of a property and nothing more.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20230310144724.1545223-1-robh@kernel.org
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
2023-03-14 21:32:13 +01:00

128 lines
3.6 KiB
C

// 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,sun9i-a80-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_property_present(dev->of_node, "interconnects"))
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);