| // 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); |