110 lines
2.9 KiB
C
110 lines
2.9 KiB
C
/*
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* Copyright (c) 2015 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/export.h>
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#include <linux/jiffies.h>
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#include <linux/regmap.h>
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#include <linux/soc/mediatek/infracfg.h>
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#include <asm/processor.h>
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#define INFRA_TOPAXI_PROTECTEN 0x0220
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#define INFRA_TOPAXI_PROTECTSTA1 0x0228
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#define INFRA_TOPAXI_PROTECTEN_SET 0x0260
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#define INFRA_TOPAXI_PROTECTEN_CLR 0x0264
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/**
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* mtk_infracfg_set_bus_protection - enable bus protection
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* @regmap: The infracfg regmap
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* @mask: The mask containing the protection bits to be enabled.
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* @reg_update: The boolean flag determines to set the protection bits
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* by regmap_update_bits with enable register(PROTECTEN) or
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* by regmap_write with set register(PROTECTEN_SET).
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*
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* This function enables the bus protection bits for disabled power
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* domains so that the system does not hang when some unit accesses the
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* bus while in power down.
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*/
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int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
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bool reg_update)
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{
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unsigned long expired;
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u32 val;
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int ret;
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if (reg_update)
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regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask,
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mask);
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else
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regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_SET, mask);
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expired = jiffies + HZ;
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while (1) {
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ret = regmap_read(infracfg, INFRA_TOPAXI_PROTECTSTA1, &val);
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if (ret)
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return ret;
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if ((val & mask) == mask)
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break;
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cpu_relax();
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if (time_after(jiffies, expired))
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return -EIO;
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}
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return 0;
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}
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/**
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* mtk_infracfg_clear_bus_protection - disable bus protection
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* @regmap: The infracfg regmap
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* @mask: The mask containing the protection bits to be disabled.
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* @reg_update: The boolean flag determines to clear the protection bits
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* by regmap_update_bits with enable register(PROTECTEN) or
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* by regmap_write with clear register(PROTECTEN_CLR).
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*
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* This function disables the bus protection bits previously enabled with
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* mtk_infracfg_set_bus_protection.
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*/
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int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
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bool reg_update)
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{
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unsigned long expired;
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int ret;
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if (reg_update)
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regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, 0);
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else
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regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_CLR, mask);
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expired = jiffies + HZ;
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while (1) {
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u32 val;
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ret = regmap_read(infracfg, INFRA_TOPAXI_PROTECTSTA1, &val);
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if (ret)
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return ret;
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if (!(val & mask))
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break;
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cpu_relax();
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if (time_after(jiffies, expired))
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return -EIO;
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}
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return 0;
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}
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