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 #include <linux/clk-provider.h>
  15
  16 static int scmi_clk_get_num_clock(struct udevice *dev, size_t *num_clocks)
  17 {
  18         struct scmi_clk_protocol_attr_out out;
  19         struct scmi_msg msg = {
  20                 .protocol_id = SCMI_PROTOCOL_ID_CLOCK,
  21                 .message_id = SCMI_PROTOCOL_ATTRIBUTES,
  22                 .out_msg = (u8 *)&out,
  23                 .out_msg_sz = sizeof(out),
  24         };
  25         int ret;
  26
  27         ret = devm_scmi_process_msg(dev, &msg);
  28         if (ret)
  29                 return ret;
  30
  31         *num_clocks = out.attributes & SCMI_CLK_PROTO_ATTR_COUNT_MASK;
  32
  33         return 0;
  34 }
  35
  36 static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name)
  37 {
  38         struct scmi_clk_attribute_in in = {
  39                 .clock_id = clkid,
  40         };
  41         struct scmi_clk_attribute_out out;
  42         struct scmi_msg msg = {
  43                 .protocol_id = SCMI_PROTOCOL_ID_CLOCK,
  44                 .message_id = SCMI_CLOCK_ATTRIBUTES,
  45                 .in_msg = (u8 *)&in,
  46                 .in_msg_sz = sizeof(in),
  47                 .out_msg = (u8 *)&out,
  48                 .out_msg_sz = sizeof(out),
  49         };
  50         int ret;
  51
  52         ret = devm_scmi_process_msg(dev, &msg);
  53         if (ret)
  54                 return ret;
  55
  56         *name = out.clock_name;
  57
  58         return 0;
  59 }
  60
  61 static int scmi_clk_gate(struct clk *clk, int enable)
  62 {
  63         struct scmi_clk_state_in in = {
  64                 .clock_id = clk->id,
  65                 .attributes = enable,
  66         };
  67         struct scmi_clk_state_out out;
  68         struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
  69                                           SCMI_CLOCK_CONFIG_SET,
  70                                           in, out);
  71         int ret;
  72
  73         ret = devm_scmi_process_msg(clk->dev, &msg);
  74         if (ret)
  75                 return ret;
  76
  77         return scmi_to_linux_errno(out.status);
  78 }
  79
  80 static int scmi_clk_enable(struct clk *clk)
  81 {
  82         return scmi_clk_gate(clk, 1);
  83 }
  84
  85 static int scmi_clk_disable(struct clk *clk)
  86 {
  87         return scmi_clk_gate(clk, 0);
  88 }
  89
  90 static ulong scmi_clk_get_rate(struct clk *clk)
  91 {
  92         struct scmi_clk_rate_get_in in = {
  93                 .clock_id = clk->id,
  94         };
  95         struct scmi_clk_rate_get_out out;
  96         struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
  97                                           SCMI_CLOCK_RATE_GET,
  98                                           in, out);
  99         int ret;
 100
 101         ret = devm_scmi_process_msg(clk->dev, &msg);
 102         if (ret < 0)
 103                 return ret;
 104
 105         ret = scmi_to_linux_errno(out.status);
 106         if (ret < 0)
 107                 return ret;
 108
 109         return (ulong)(((u64)out.rate_msb << 32) | out.rate_lsb);
 110 }
 111
 112 static ulong scmi_clk_set_rate(struct clk *clk, ulong rate)
 113 {
 114         struct scmi_clk_rate_set_in in = {
 115                 .clock_id = clk->id,
 116                 .flags = SCMI_CLK_RATE_ROUND_CLOSEST,
 117                 .rate_lsb = (u32)rate,
 118                 .rate_msb = (u32)((u64)rate >> 32),
 119         };
 120         struct scmi_clk_rate_set_out out;
 121         struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
 122                                           SCMI_CLOCK_RATE_SET,
 123                                           in, out);
 124         int ret;
 125
 126         ret = devm_scmi_process_msg(clk->dev, &msg);
 127         if (ret < 0)
 128                 return ret;
 129
 130         ret = scmi_to_linux_errno(out.status);
 131         if (ret < 0)
 132                 return ret;
 133
 134         return scmi_clk_get_rate(clk);
 135 }
 136
 137 static int scmi_clk_probe(struct udevice *dev)
 138 {
 139         struct clk *clk;
 140         size_t num_clocks, i;
 141         int ret;
 142
 143         if (!CONFIG_IS_ENABLED(CLK_CCF))
 144                 return 0;
 145
 146         /* register CCF children: CLK UCLASS, no probed again */
 147         if (device_get_uclass_id(dev->parent) == UCLASS_CLK)
 148                 return 0;
 149
 150         ret = scmi_clk_get_num_clock(dev, &num_clocks);
 151         if (ret)
 152                 return ret;
 153
 154         for (i = 0; i < num_clocks; i++) {
 155                 char *name;
 156
 157                 if (!scmi_clk_get_attibute(dev, i, &name)) {
 158                         char *clock_name = strdup(name);
 159
 160                         clk = kzalloc(sizeof(*clk), GFP_KERNEL);
 161                         if (!clk || !clock_name)
 162                                 ret = -ENOMEM;
 163                         else
 164                                 ret = clk_register(clk, dev->driver->name,
 165                                                    clock_name, dev->name);
 166
 167                         if (ret) {
 168                                 free(clk);
 169                                 free(clock_name);
 170                                 return ret;
 171                         }
 172
 173                         clk_dm(i, clk);
 174                 }
 175         }
 176
 177         return 0;
 178 }
 179
 180 static const struct clk_ops scmi_clk_ops = {
 181         .enable = scmi_clk_enable,
 182         .disable = scmi_clk_disable,
 183         .get_rate = scmi_clk_get_rate,
 184         .set_rate = scmi_clk_set_rate,
 185 };
 186
 187 U_BOOT_DRIVER(scmi_clock) = {
 188         .name = "scmi_clk",
 189         .id = UCLASS_CLK,
 190         .ops = &scmi_clk_ops,
 191         .probe = &scmi_clk_probe,
 192 };