1 // SPDX-License-Identifier: GPL-2.0-only
8  * Baikal-T1 Physically Mapped Internal ROM driver
21 #include "physmap-bt1-rom.h"
24  * Baikal-T1 SoC ROMs are only accessible by the dword-aligned instructions.
25  * We have to take this into account when implementing the data read-methods.
26  * Note there is no need in bothering with endianness, since both Baikal-T1
32 	void __iomem *src = map->virt + ofs;  in bt1_rom_map_read()
33 	unsigned int shift;  in bt1_rom_map_read()  local
35 	u32 data;  in bt1_rom_map_read()  local
37 	/* Read data within offset dword. */  in bt1_rom_map_read()
38 	shift = (uintptr_t)src & 0x3;  in bt1_rom_map_read()
39 	data = readl_relaxed(src - shift);  in bt1_rom_map_read()
40 	if (!shift) {  in bt1_rom_map_read()
41 		ret.x[0] = data;  in bt1_rom_map_read()
44 	ret.x[0] = data >> (shift * BITS_PER_BYTE);  in bt1_rom_map_read()
46 	/* Read data from the next dword. */  in bt1_rom_map_read()
47 	shift = 4 - shift;  in bt1_rom_map_read()
48 	if (ofs + shift >= map->size)  in bt1_rom_map_read()
51 	data = readl_relaxed(src + shift);  in bt1_rom_map_read()
52 	ret.x[0] |= data << (shift * BITS_PER_BYTE);  in bt1_rom_map_read()
61 	void __iomem *src = map->virt + from;  in bt1_rom_map_copy_from()
62 	unsigned int shift, chunk;  in bt1_rom_map_copy_from()  local
63 	u32 data;  in bt1_rom_map_copy_from()  local
65 	if (len <= 0 || from >= map->size)  in bt1_rom_map_copy_from()
69 	len = min_t(ssize_t, map->size - from, len);  in bt1_rom_map_copy_from()
72 	 * Since requested data size can be pretty big we have to implement  in bt1_rom_map_copy_from()
77 	shift = (uintptr_t)src & 0x3;  in bt1_rom_map_copy_from()
78 	if (shift) {  in bt1_rom_map_copy_from()
79 		chunk = min_t(ssize_t, 4 - shift, len);  in bt1_rom_map_copy_from()
80 		data = readl_relaxed(src - shift);  in bt1_rom_map_copy_from()
81 		memcpy(to, (char *)&data + shift, chunk);  in bt1_rom_map_copy_from()
84 		len -= chunk;  in bt1_rom_map_copy_from()
88 		data = readl_relaxed(src);  in bt1_rom_map_copy_from()
89 		memcpy(to, &data, 4);  in bt1_rom_map_copy_from()
92 		len -= 4;  in bt1_rom_map_copy_from()
96 		data = readl_relaxed(src);  in bt1_rom_map_copy_from()
97 		memcpy(to, &data, len);  in bt1_rom_map_copy_from()
105 	struct device *dev = &pdev->dev;  in of_flash_probe_bt1_rom()
107 	/* It's supposed to be read-only MTD. */  in of_flash_probe_bt1_rom()
108 	if (!of_device_is_compatible(np, "mtd-rom")) {  in of_flash_probe_bt1_rom()
109 		dev_info(dev, "No mtd-rom compatible string\n");  in of_flash_probe_bt1_rom()
114 	if (!of_device_is_compatible(np, "baikal,bt1-int-rom"))  in of_flash_probe_bt1_rom()
118 	if (map->bankwidth != 4)  in of_flash_probe_bt1_rom()
121 	map->read = bt1_rom_map_read;  in of_flash_probe_bt1_rom()
122 	map->copy_from = bt1_rom_map_copy_from;  in of_flash_probe_bt1_rom()