drivers/reset/reset-scmi.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2019-2022 Linaro Limited
   4  */
   5
   6 #define LOG_CATEGORY UCLASS_RESET
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <errno.h>
  11 #include <reset-uclass.h>
  12 #include <scmi_agent.h>
  13 #include <scmi_protocols.h>
  14 #include <asm/types.h>
  15
  16 /**
  17  * struct scmi_reset_priv - Private data for SCMI reset controller
  18  * @channel: Reference to the SCMI channel to use
  19  */
  20 struct scmi_reset_priv {
  21         struct scmi_channel *channel;
  22 };
  23
  24 static int scmi_reset_set_level(struct reset_ctl *rst, bool assert_not_deassert)
  25 {
  26         struct scmi_reset_priv *priv = dev_get_priv(rst->dev);
  27         struct scmi_rd_reset_in in = {
  28                 .domain_id = rst->id,
  29                 .flags = assert_not_deassert ? SCMI_RD_RESET_FLAG_ASSERT : 0,
  30                 .reset_state = 0,
  31         };
  32         struct scmi_rd_reset_out out;
  33         struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_RESET_DOMAIN,
  34                                           SCMI_RESET_DOMAIN_RESET,
  35                                           in, out);
  36         int ret;
  37
  38         ret = devm_scmi_process_msg(rst->dev, priv->channel, &msg);
  39         if (ret)
  40                 return ret;
  41
  42         return scmi_to_linux_errno(out.status);
  43 }
  44
  45 static int scmi_reset_assert(struct reset_ctl *rst)
  46 {
  47         return scmi_reset_set_level(rst, true);
  48 }
  49
  50 static int scmi_reset_deassert(struct reset_ctl *rst)
  51 {
  52         return scmi_reset_set_level(rst, false);
  53 }
  54
  55 static int scmi_reset_request(struct reset_ctl *rst)
  56 {
  57         struct scmi_reset_priv *priv = dev_get_priv(rst->dev);
  58         struct scmi_rd_attr_in in = {
  59                 .domain_id = rst->id,
  60         };
  61         struct scmi_rd_attr_out out;
  62         struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_RESET_DOMAIN,
  63                                           SCMI_RESET_DOMAIN_ATTRIBUTES,
  64                                           in, out);
  65         int ret;
  66
  67         /*
  68          * We don't really care about the attribute, just check
  69          * the reset domain exists.
  70          */
  71         ret = devm_scmi_process_msg(rst->dev, priv->channel, &msg);
  72         if (ret)
  73                 return ret;
  74
  75         return scmi_to_linux_errno(out.status);
  76 }
  77
  78 static const struct reset_ops scmi_reset_domain_ops = {
  79         .request        = scmi_reset_request,
  80         .rst_assert     = scmi_reset_assert,
  81         .rst_deassert   = scmi_reset_deassert,
  82 };
  83
  84 static int scmi_reset_probe(struct udevice *dev)
  85 {
  86         struct scmi_reset_priv *priv = dev_get_priv(dev);
  87
  88         return devm_scmi_of_get_channel(dev, &priv->channel);
  89 }
  90
  91 U_BOOT_DRIVER(scmi_reset_domain) = {
  92         .name = "scmi_reset_domain",
  93         .id = UCLASS_RESET,
  94         .ops = &scmi_reset_domain_ops,
  95         .probe = scmi_reset_probe,
  96         .priv_auto = sizeof(struct scmi_reset_priv *),
  97 };