linux/arch/arm/mach-imx/mach-imx7ulp.c
Fabio Estevam 7544bfc086 ARM: imx: imx7ulp: Add a comment explaining the B2 silicon version
To help the users to understand the meaning of bits 31-28 of the
JTAG_ID_REG register, add a comment explaining the value that is
expected from a i.MX7ULP rev B2.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2020-11-10 09:56:01 +08:00

85 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2016 Freescale Semiconductor, Inc.
* Copyright 2017-2018 NXP
* Author: Dong Aisheng <aisheng.dong@nxp.com>
*/
#include <linux/irqchip.h>
#include <linux/mfd/syscon.h>
#include <linux/of_platform.h>
#include <linux/regmap.h>
#include <asm/mach/arch.h>
#include "common.h"
#include "cpuidle.h"
#include "hardware.h"
#define SIM_JTAG_ID_REG 0x8c
static void __init imx7ulp_set_revision(void)
{
struct regmap *sim;
u32 revision;
sim = syscon_regmap_lookup_by_compatible("fsl,imx7ulp-sim");
if (IS_ERR(sim)) {
pr_warn("failed to find fsl,imx7ulp-sim regmap!\n");
return;
}
if (regmap_read(sim, SIM_JTAG_ID_REG, &revision)) {
pr_warn("failed to read sim regmap!\n");
return;
}
/*
* bit[31:28] of JTAG_ID register defines revision as below from B0:
* 0001 B0
* 0010 B1
* 0011 B2
*/
switch (revision >> 28) {
case 1:
imx_set_soc_revision(IMX_CHIP_REVISION_2_0);
break;
case 2:
imx_set_soc_revision(IMX_CHIP_REVISION_2_1);
break;
case 3:
imx_set_soc_revision(IMX_CHIP_REVISION_2_2);
break;
default:
imx_set_soc_revision(IMX_CHIP_REVISION_1_0);
break;
}
}
static void __init imx7ulp_init_machine(void)
{
imx7ulp_pm_init();
mxc_set_cpu_type(MXC_CPU_IMX7ULP);
imx7ulp_set_revision();
of_platform_default_populate(NULL, NULL, NULL);
}
static const char *const imx7ulp_dt_compat[] __initconst = {
"fsl,imx7ulp",
NULL,
};
static void __init imx7ulp_init_late(void)
{
if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
imx7ulp_cpuidle_init();
}
DT_MACHINE_START(IMX7ulp, "Freescale i.MX7ULP (Device Tree)")
.init_machine = imx7ulp_init_machine,
.dt_compat = imx7ulp_dt_compat,
.init_late = imx7ulp_init_late,
MACHINE_END