drivers/clk/clk_scmi.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2019-2020 Linaro Limited
   4  */
   5
   6 #define LOG_CATEGORY UCLASS_CLK
   7
   8 #include <common.h>
   9 #include <clk-uclass.h>
  10 #include <dm.h>
  11 #include <scmi_agent.h>
  12 #include <scmi_protocols.h>
  13 #include <asm/types.h>
  14
  15 static int scmi_clk_gate(struct clk *clk, int enable)
  16 {
  17         struct scmi_clk_state_in in = {
  18                 .clock_id = clk->id,
  19                 .attributes = enable,
  20         };
  21         struct scmi_clk_state_out out;
  22         struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
  23                                           SCMI_CLOCK_CONFIG_SET,
  24                                           in, out);
  25         int ret;
  26
  27         ret = devm_scmi_process_msg(clk->dev->parent, &msg);
  28         if (ret)
  29                 return ret;
  30
  31         return scmi_to_linux_errno(out.status);
  32 }
  33
  34 static int scmi_clk_enable(struct clk *clk)
  35 {
  36         return scmi_clk_gate(clk, 1);
  37 }
  38
  39 static int scmi_clk_disable(struct clk *clk)
  40 {
  41         return scmi_clk_gate(clk, 0);
  42 }
  43
  44 static ulong scmi_clk_get_rate(struct clk *clk)
  45 {
  46         struct scmi_clk_rate_get_in in = {
  47                 .clock_id = clk->id,
  48         };
  49         struct scmi_clk_rate_get_out out;
  50         struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
  51                                           SCMI_CLOCK_RATE_GET,
  52                                           in, out);
  53         int ret;
  54
  55         ret = devm_scmi_process_msg(clk->dev->parent, &msg);
  56         if (ret < 0)
  57                 return ret;
  58
  59         ret = scmi_to_linux_errno(out.status);
  60         if (ret < 0)
  61                 return ret;
  62
  63         return (ulong)(((u64)out.rate_msb << 32) | out.rate_lsb);
  64 }
  65
  66 static ulong scmi_clk_set_rate(struct clk *clk, ulong rate)
  67 {
  68         struct scmi_clk_rate_set_in in = {
  69                 .clock_id = clk->id,
  70                 .flags = SCMI_CLK_RATE_ROUND_CLOSEST,
  71                 .rate_lsb = (u32)rate,
  72                 .rate_msb = (u32)((u64)rate >> 32),
  73         };
  74         struct scmi_clk_rate_set_out out;
  75         struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
  76                                           SCMI_CLOCK_RATE_SET,
  77                                           in, out);
  78         int ret;
  79
  80         ret = devm_scmi_process_msg(clk->dev->parent, &msg);
  81         if (ret < 0)
  82                 return ret;
  83
  84         ret = scmi_to_linux_errno(out.status);
  85         if (ret < 0)
  86                 return ret;
  87
  88         return scmi_clk_get_rate(clk);
  89 }
  90
  91 static const struct clk_ops scmi_clk_ops = {
  92         .enable = scmi_clk_enable,
  93         .disable = scmi_clk_disable,
  94         .get_rate = scmi_clk_get_rate,
  95         .set_rate = scmi_clk_set_rate,
  96 };
  97
  98 U_BOOT_DRIVER(scmi_clock) = {
  99         .name = "scmi_clk",
 100         .id = UCLASS_CLK,
 101         .ops = &scmi_clk_ops,
 102 };