1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2017 Linaro Ltd. |
4 | * |
5 | * Author: Linus Walleij <linus.walleij@linaro.org> |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify |
8 | * it under the terms of the GNU General Public License version 2, as |
9 | * published by the Free Software Foundation. |
10 | * |
11 | */ |
12 | #include <linux/init.h> |
13 | #include <linux/kernel.h> |
14 | #include <linux/mfd/syscon.h> |
15 | #include <linux/regmap.h> |
16 | #include <linux/of.h> |
17 | |
18 | #define GLOBAL_WORD_ID 0x00 |
19 | #define GEMINI_GLOBAL_ARB1_CTRL 0x2c |
20 | #define GEMINI_ARB1_BURST_MASK GENMASK(21, 16) |
21 | #define GEMINI_ARB1_BURST_SHIFT 16 |
22 | /* These all define the priority on the BUS2 backplane */ |
23 | #define GEMINI_ARB1_PRIO_MASK GENMASK(9, 0) |
24 | #define GEMINI_ARB1_DMAC_HIGH_PRIO BIT(0) |
25 | #define GEMINI_ARB1_IDE_HIGH_PRIO BIT(1) |
26 | #define GEMINI_ARB1_RAID_HIGH_PRIO BIT(2) |
27 | #define GEMINI_ARB1_SECURITY_HIGH_PRIO BIT(3) |
28 | #define GEMINI_ARB1_GMAC0_HIGH_PRIO BIT(4) |
29 | #define GEMINI_ARB1_GMAC1_HIGH_PRIO BIT(5) |
30 | #define GEMINI_ARB1_USB0_HIGH_PRIO BIT(6) |
31 | #define GEMINI_ARB1_USB1_HIGH_PRIO BIT(7) |
32 | #define GEMINI_ARB1_PCI_HIGH_PRIO BIT(8) |
33 | #define GEMINI_ARB1_TVE_HIGH_PRIO BIT(9) |
34 | |
35 | #define GEMINI_DEFAULT_BURST_SIZE 0x20 |
36 | #define GEMINI_DEFAULT_PRIO (GEMINI_ARB1_GMAC0_HIGH_PRIO | \ |
37 | GEMINI_ARB1_GMAC1_HIGH_PRIO) |
38 | |
39 | static int __init gemini_soc_init(void) |
40 | { |
41 | struct regmap *map; |
42 | u32 rev; |
43 | u32 val; |
44 | int ret; |
45 | |
46 | /* Multiplatform guard, only proceed on Gemini */ |
47 | if (!of_machine_is_compatible(compat: "cortina,gemini" )) |
48 | return 0; |
49 | |
50 | map = syscon_regmap_lookup_by_compatible(s: "cortina,gemini-syscon" ); |
51 | if (IS_ERR(ptr: map)) |
52 | return PTR_ERR(ptr: map); |
53 | ret = regmap_read(map, GLOBAL_WORD_ID, val: &rev); |
54 | if (ret) |
55 | return ret; |
56 | |
57 | val = (GEMINI_DEFAULT_BURST_SIZE << GEMINI_ARB1_BURST_SHIFT) | |
58 | GEMINI_DEFAULT_PRIO; |
59 | |
60 | /* Set up system arbitration */ |
61 | regmap_update_bits(map, |
62 | GEMINI_GLOBAL_ARB1_CTRL, |
63 | GEMINI_ARB1_BURST_MASK | GEMINI_ARB1_PRIO_MASK, |
64 | val); |
65 | |
66 | pr_info("Gemini SoC %04x revision %02x, set arbitration %08x\n" , |
67 | rev >> 8, rev & 0xff, val); |
68 | |
69 | return 0; |
70 | } |
71 | subsys_initcall(gemini_soc_init); |
72 | |