drivers/soc/mediatek/mtk-infracfg.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
   4  */
   5
   6 #include <linux/export.h>
   7 #include <linux/jiffies.h>
   8 #include <linux/regmap.h>
   9 #include <linux/soc/mediatek/infracfg.h>
  10 #include <asm/processor.h>
  11
  12 #define MTK_POLL_DELAY_US   10
  13 #define MTK_POLL_TIMEOUT    (jiffies_to_usecs(HZ))
  14
  15 /**
  16  * mtk_infracfg_set_bus_protection - enable bus protection
  17  * @infracfg: The infracfg regmap
  18  * @mask: The mask containing the protection bits to be enabled.
  19  * @reg_update: The boolean flag determines to set the protection bits
  20  *              by regmap_update_bits with enable register(PROTECTEN) or
  21  *              by regmap_write with set register(PROTECTEN_SET).
  22  *
  23  * This function enables the bus protection bits for disabled power
  24  * domains so that the system does not hang when some unit accesses the
  25  * bus while in power down.
  26  */
  27 int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
  28                 bool reg_update)
  29 {
  30         u32 val;
  31         int ret;
  32
  33         if (reg_update)
  34                 regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask,
  35                                 mask);
  36         else
  37                 regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_SET, mask);
  38
  39         ret = regmap_read_poll_timeout(infracfg, INFRA_TOPAXI_PROTECTSTA1,
  40                                        val, (val & mask) == mask,
  41                                        MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
  42
  43         return ret;
  44 }
  45
  46 /**
  47  * mtk_infracfg_clear_bus_protection - disable bus protection
  48  * @infracfg: The infracfg regmap
  49  * @mask: The mask containing the protection bits to be disabled.
  50  * @reg_update: The boolean flag determines to clear the protection bits
  51  *              by regmap_update_bits with enable register(PROTECTEN) or
  52  *              by regmap_write with clear register(PROTECTEN_CLR).
  53  *
  54  * This function disables the bus protection bits previously enabled with
  55  * mtk_infracfg_set_bus_protection.
  56  */
  57
  58 int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
  59                 bool reg_update)
  60 {
  61         int ret;
  62         u32 val;
  63
  64         if (reg_update)
  65                 regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, 0);
  66         else
  67                 regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_CLR, mask);
  68
  69         ret = regmap_read_poll_timeout(infracfg, INFRA_TOPAXI_PROTECTSTA1,
  70                                        val, !(val & mask),
  71                                        MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
  72
  73         return ret;
  74 }