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1// SPDX-License-Identifier: GPL-2.02/*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 modify8 * it under the terms of the GNU General Public License version 2, as9 * 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 0x0019#define GEMINI_GLOBAL_ARB1_CTRL 0x2c20#define GEMINI_ARB1_BURST_MASK GENMASK(21, 16)21#define GEMINI_ARB1_BURST_SHIFT 1622/* 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 0x2036#define GEMINI_DEFAULT_PRIO (GEMINI_ARB1_GMAC0_HIGH_PRIO | \37 GEMINI_ARB1_GMAC1_HIGH_PRIO)38 39static 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}71subsys_initcall(gemini_soc_init);72