linux/drivers/soc/gemini/soc-gemini.c

72 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2017 Linaro Ltd.
*
* Author: Linus Walleij <linus.walleij@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2, as
* published by the Free Software Foundation.
*
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/of.h>
#define GLOBAL_WORD_ID 0x00
#define GEMINI_GLOBAL_ARB1_CTRL 0x2c
#define GEMINI_ARB1_BURST_MASK GENMASK(21, 16)
#define GEMINI_ARB1_BURST_SHIFT 16
/* These all define the priority on the BUS2 backplane */
#define GEMINI_ARB1_PRIO_MASK GENMASK(9, 0)
#define GEMINI_ARB1_DMAC_HIGH_PRIO BIT(0)
#define GEMINI_ARB1_IDE_HIGH_PRIO BIT(1)
#define GEMINI_ARB1_RAID_HIGH_PRIO BIT(2)
#define GEMINI_ARB1_SECURITY_HIGH_PRIO BIT(3)
#define GEMINI_ARB1_GMAC0_HIGH_PRIO BIT(4)
#define GEMINI_ARB1_GMAC1_HIGH_PRIO BIT(5)
#define GEMINI_ARB1_USB0_HIGH_PRIO BIT(6)
#define GEMINI_ARB1_USB1_HIGH_PRIO BIT(7)
#define GEMINI_ARB1_PCI_HIGH_PRIO BIT(8)
#define GEMINI_ARB1_TVE_HIGH_PRIO BIT(9)
#define GEMINI_DEFAULT_BURST_SIZE 0x20
#define GEMINI_DEFAULT_PRIO (GEMINI_ARB1_GMAC0_HIGH_PRIO | \
GEMINI_ARB1_GMAC1_HIGH_PRIO)
static int __init gemini_soc_init(void)
{
struct regmap *map;
u32 rev;
u32 val;
int ret;
/* Multiplatform guard, only proceed on Gemini */
if (!of_machine_is_compatible("cortina,gemini"))
return 0;
map = syscon_regmap_lookup_by_compatible("cortina,gemini-syscon");
if (IS_ERR(map))
return PTR_ERR(map);
ret = regmap_read(map, GLOBAL_WORD_ID, &rev);
if (ret)
return ret;
val = (GEMINI_DEFAULT_BURST_SIZE << GEMINI_ARB1_BURST_SHIFT) |
GEMINI_DEFAULT_PRIO;
/* Set up system arbitration */
regmap_update_bits(map,
GEMINI_GLOBAL_ARB1_CTRL,
GEMINI_ARB1_BURST_MASK | GEMINI_ARB1_PRIO_MASK,
val);
pr_info("Gemini SoC %04x revision %02x, set arbitration %08x\n",
rev >> 8, rev & 0xff, val);
return 0;
}
subsys_initcall(gemini_soc_init);