u-boot/drivers/misc/fsl_devdis.c
Zhuoyu Zhang 03c22449c5 arm/ls102xa:add hwconfig setting to support disable unused devices
DEVDISRn registers provides a mechanism for gating clocks of IP blocks
that are not used. Here we implement hwconfig option to allow users
to disable unused peripherals on the board.

For ex. If eSDHC/qDMA/eDMA are unused and with disabled status in dts,
User can enable CONFIG_FSL_DEVICE_DISABLE and set "devdis:esdhc,qdma,edma"
in hwconfig, thus ESDHC controller & eDMA/qDMA will be clock gated to
save more power.

Signed-off-by: Zhuoyu Zhang <Zhuoyu.Zhang@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
2015-09-01 21:49:20 -05:00

30 lines
704 B
C

/*
* Copyright 2015 Freescale Semiconductor, Inc.
* Author: Zhuoyu Zhang <Zhuoyu.Zhang@freescale.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch-ls102xa/immap_ls102xa.h>
#include <asm/arch-ls102xa/config.h>
#include <linux/compiler.h>
#include <hwconfig.h>
#include <fsl_devdis.h>
void device_disable(const struct devdis_table *tbl, uint32_t num)
{
int i;
struct ccsr_gur __iomem *gur = (void *)CONFIG_SYS_FSL_GUTS_ADDR;
/*
* Extract hwconfig from environment and disable unused device.
*/
for (i = 0; i < num; i++) {
if (hwconfig_sub("devdis", tbl[i].name))
setbits_be32(&gur->devdisr + tbl[i].offset,
tbl[i].mask);
}
}