linux_dsm_epyc7002/drivers/soc/mediatek/mtk-infracfg.c
weiyi.lu@mediatek.com fa7e843a90 soc: mediatek: extend bus protection API
MT2712 add "set/clear" bus control register to each control register set
instead of providing only one "enable" control register, we could avoid
the read-modify-write racing by declaring "bus_prot_reg_update" as "false"
in scp_soc_data or declaring as "true" to use the legacy update method.
By improving the mtk-infracfg bus protection implementation to
support set/clear bus protection control method by IC configuration.

Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
2017-12-21 11:49:22 +01:00

110 lines
2.9 KiB
C

/*
* Copyright (c) 2015 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/export.h>
#include <linux/jiffies.h>
#include <linux/regmap.h>
#include <linux/soc/mediatek/infracfg.h>
#include <asm/processor.h>
#define INFRA_TOPAXI_PROTECTEN 0x0220
#define INFRA_TOPAXI_PROTECTSTA1 0x0228
#define INFRA_TOPAXI_PROTECTEN_SET 0x0260
#define INFRA_TOPAXI_PROTECTEN_CLR 0x0264
/**
* mtk_infracfg_set_bus_protection - enable bus protection
* @regmap: The infracfg regmap
* @mask: The mask containing the protection bits to be enabled.
* @reg_update: The boolean flag determines to set the protection bits
* by regmap_update_bits with enable register(PROTECTEN) or
* by regmap_write with set register(PROTECTEN_SET).
*
* This function enables the bus protection bits for disabled power
* domains so that the system does not hang when some unit accesses the
* bus while in power down.
*/
int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
bool reg_update)
{
unsigned long expired;
u32 val;
int ret;
if (reg_update)
regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask,
mask);
else
regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_SET, mask);
expired = jiffies + HZ;
while (1) {
ret = regmap_read(infracfg, INFRA_TOPAXI_PROTECTSTA1, &val);
if (ret)
return ret;
if ((val & mask) == mask)
break;
cpu_relax();
if (time_after(jiffies, expired))
return -EIO;
}
return 0;
}
/**
* mtk_infracfg_clear_bus_protection - disable bus protection
* @regmap: The infracfg regmap
* @mask: The mask containing the protection bits to be disabled.
* @reg_update: The boolean flag determines to clear the protection bits
* by regmap_update_bits with enable register(PROTECTEN) or
* by regmap_write with clear register(PROTECTEN_CLR).
*
* This function disables the bus protection bits previously enabled with
* mtk_infracfg_set_bus_protection.
*/
int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
bool reg_update)
{
unsigned long expired;
int ret;
if (reg_update)
regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, 0);
else
regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_CLR, mask);
expired = jiffies + HZ;
while (1) {
u32 val;
ret = regmap_read(infracfg, INFRA_TOPAXI_PROTECTSTA1, &val);
if (ret)
return ret;
if (!(val & mask))
break;
cpu_relax();
if (time_after(jiffies, expired))
return -EIO;
}
return 0;
}