1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2017 Linaro Ltd.
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Author: Linus Walleij <linus.walleij@linaro.org>
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * This program is free software; you can redistribute it and/or modify
8*4882a593Smuzhiyun * it under the terms of the GNU General Public License version 2, as
9*4882a593Smuzhiyun * published by the Free Software Foundation.
10*4882a593Smuzhiyun *
11*4882a593Smuzhiyun */
12*4882a593Smuzhiyun #include <linux/init.h>
13*4882a593Smuzhiyun #include <linux/kernel.h>
14*4882a593Smuzhiyun #include <linux/mfd/syscon.h>
15*4882a593Smuzhiyun #include <linux/regmap.h>
16*4882a593Smuzhiyun #include <linux/of.h>
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun #define GLOBAL_WORD_ID 0x00
19*4882a593Smuzhiyun #define GEMINI_GLOBAL_ARB1_CTRL 0x2c
20*4882a593Smuzhiyun #define GEMINI_ARB1_BURST_MASK GENMASK(21, 16)
21*4882a593Smuzhiyun #define GEMINI_ARB1_BURST_SHIFT 16
22*4882a593Smuzhiyun /* These all define the priority on the BUS2 backplane */
23*4882a593Smuzhiyun #define GEMINI_ARB1_PRIO_MASK GENMASK(9, 0)
24*4882a593Smuzhiyun #define GEMINI_ARB1_DMAC_HIGH_PRIO BIT(0)
25*4882a593Smuzhiyun #define GEMINI_ARB1_IDE_HIGH_PRIO BIT(1)
26*4882a593Smuzhiyun #define GEMINI_ARB1_RAID_HIGH_PRIO BIT(2)
27*4882a593Smuzhiyun #define GEMINI_ARB1_SECURITY_HIGH_PRIO BIT(3)
28*4882a593Smuzhiyun #define GEMINI_ARB1_GMAC0_HIGH_PRIO BIT(4)
29*4882a593Smuzhiyun #define GEMINI_ARB1_GMAC1_HIGH_PRIO BIT(5)
30*4882a593Smuzhiyun #define GEMINI_ARB1_USB0_HIGH_PRIO BIT(6)
31*4882a593Smuzhiyun #define GEMINI_ARB1_USB1_HIGH_PRIO BIT(7)
32*4882a593Smuzhiyun #define GEMINI_ARB1_PCI_HIGH_PRIO BIT(8)
33*4882a593Smuzhiyun #define GEMINI_ARB1_TVE_HIGH_PRIO BIT(9)
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun #define GEMINI_DEFAULT_BURST_SIZE 0x20
36*4882a593Smuzhiyun #define GEMINI_DEFAULT_PRIO (GEMINI_ARB1_GMAC0_HIGH_PRIO | \
37*4882a593Smuzhiyun GEMINI_ARB1_GMAC1_HIGH_PRIO)
38*4882a593Smuzhiyun
gemini_soc_init(void)39*4882a593Smuzhiyun static int __init gemini_soc_init(void)
40*4882a593Smuzhiyun {
41*4882a593Smuzhiyun struct regmap *map;
42*4882a593Smuzhiyun u32 rev;
43*4882a593Smuzhiyun u32 val;
44*4882a593Smuzhiyun int ret;
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun /* Multiplatform guard, only proceed on Gemini */
47*4882a593Smuzhiyun if (!of_machine_is_compatible("cortina,gemini"))
48*4882a593Smuzhiyun return 0;
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun map = syscon_regmap_lookup_by_compatible("cortina,gemini-syscon");
51*4882a593Smuzhiyun if (IS_ERR(map))
52*4882a593Smuzhiyun return PTR_ERR(map);
53*4882a593Smuzhiyun ret = regmap_read(map, GLOBAL_WORD_ID, &rev);
54*4882a593Smuzhiyun if (ret)
55*4882a593Smuzhiyun return ret;
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun val = (GEMINI_DEFAULT_BURST_SIZE << GEMINI_ARB1_BURST_SHIFT) |
58*4882a593Smuzhiyun GEMINI_DEFAULT_PRIO;
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun /* Set up system arbitration */
61*4882a593Smuzhiyun regmap_update_bits(map,
62*4882a593Smuzhiyun GEMINI_GLOBAL_ARB1_CTRL,
63*4882a593Smuzhiyun GEMINI_ARB1_BURST_MASK | GEMINI_ARB1_PRIO_MASK,
64*4882a593Smuzhiyun val);
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun pr_info("Gemini SoC %04x revision %02x, set arbitration %08x\n",
67*4882a593Smuzhiyun rev >> 8, rev & 0xff, val);
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun return 0;
70*4882a593Smuzhiyun }
71*4882a593Smuzhiyun subsys_initcall(gemini_soc_init);
72