drivers/soc/mediatek/mtk-infracfg.c

   1 /*
   2  * Copyright (c) 2015 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/export.h>
  15 #include <linux/jiffies.h>
  16 #include <linux/regmap.h>
  17 #include <linux/soc/mediatek/infracfg.h>
  18 #include <asm/processor.h>
  19
  20 #define MTK_POLL_DELAY_US   10
  21 #define MTK_POLL_TIMEOUT    (jiffies_to_usecs(HZ))
  22
  23 #define INFRA_TOPAXI_PROTECTEN          0x0220
  24 #define INFRA_TOPAXI_PROTECTSTA1        0x0228
  25 #define INFRA_TOPAXI_PROTECTEN_SET      0x0260
  26 #define INFRA_TOPAXI_PROTECTEN_CLR      0x0264
  27
  28 /**
  29  * mtk_infracfg_set_bus_protection - enable bus protection
  30  * @regmap: The infracfg regmap
  31  * @mask: The mask containing the protection bits to be enabled.
  32  * @reg_update: The boolean flag determines to set the protection bits
  33  *              by regmap_update_bits with enable register(PROTECTEN) or
  34  *              by regmap_write with set register(PROTECTEN_SET).
  35  *
  36  * This function enables the bus protection bits for disabled power
  37  * domains so that the system does not hang when some unit accesses the
  38  * bus while in power down.
  39  */
  40 int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
  41                 bool reg_update)
  42 {
  43         u32 val;
  44         int ret;
  45
  46         if (reg_update)
  47                 regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask,
  48                                 mask);
  49         else
  50                 regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_SET, mask);
  51
  52         ret = regmap_read_poll_timeout(infracfg, INFRA_TOPAXI_PROTECTSTA1,
  53                                        val, (val & mask) == mask,
  54                                        MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
  55
  56         return ret;
  57 }
  58
  59 /**
  60  * mtk_infracfg_clear_bus_protection - disable bus protection
  61  * @regmap: The infracfg regmap
  62  * @mask: The mask containing the protection bits to be disabled.
  63  * @reg_update: The boolean flag determines to clear the protection bits
  64  *              by regmap_update_bits with enable register(PROTECTEN) or
  65  *              by regmap_write with clear register(PROTECTEN_CLR).
  66  *
  67  * This function disables the bus protection bits previously enabled with
  68  * mtk_infracfg_set_bus_protection.
  69  */
  70
  71 int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
  72                 bool reg_update)
  73 {
  74         int ret;
  75         u32 val;
  76
  77         if (reg_update)
  78                 regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, 0);
  79         else
  80                 regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_CLR, mask);
  81
  82         ret = regmap_read_poll_timeout(infracfg, INFRA_TOPAXI_PROTECTSTA1,
  83                                        val, !(val & mask),
  84                                        MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
  85
  86         return ret;
  87 }