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("cortina,gemini")) 48 return 0; 49 50 map = syscon_regmap_lookup_by_compatible("cortina,gemini-syscon"); 51 if (IS_ERR(map)) 52 return PTR_ERR(map); 53 ret = regmap_read(map, GLOBAL_WORD_ID, &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