drivers/clk/x86/clk-st.c

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * clock framework for AMD Stoney based clocks
   4  *
   5  * Copyright 2018 Advanced Micro Devices, Inc.
   6  */
   7
   8 #include <linux/clk.h>
   9 #include <linux/clkdev.h>
  10 #include <linux/clk-provider.h>
  11 #include <linux/platform_data/clk-st.h>
  12 #include <linux/platform_device.h>
  13
  14 /* Clock Driving Strength 2 register */
  15 #define CLKDRVSTR2      0x28
  16 /* Clock Control 1 register */
  17 #define MISCCLKCNTL1    0x40
  18 /* Auxiliary clock1 enable bit */
  19 #define OSCCLKENB       2
  20 /* 25Mhz auxiliary output clock freq bit */
  21 #define OSCOUT1CLK25MHZ 16
  22
  23 #define ST_CLK_48M      0
  24 #define ST_CLK_25M      1
  25 #define ST_CLK_MUX      2
  26 #define ST_CLK_GATE     3
  27 #define ST_MAX_CLKS     4
  28
  29 static const char * const clk_oscout1_parents[] = { "clk48MHz", "clk25MHz" };
  30 static struct clk_hw *hws[ST_MAX_CLKS];
  31
  32 static int st_clk_probe(struct platform_device *pdev)
  33 {
  34         struct st_clk_data *st_data;
  35
  36         st_data = dev_get_platdata(&pdev->dev);
  37         if (!st_data || !st_data->base)
  38                 return -EINVAL;
  39
  40         hws[ST_CLK_48M] = clk_hw_register_fixed_rate(NULL, "clk48MHz", NULL, 0,
  41                                                      48000000);
  42         hws[ST_CLK_25M] = clk_hw_register_fixed_rate(NULL, "clk25MHz", NULL, 0,
  43                                                      25000000);
  44
  45         hws[ST_CLK_MUX] = clk_hw_register_mux(NULL, "oscout1_mux",
  46                 clk_oscout1_parents, ARRAY_SIZE(clk_oscout1_parents),
  47                 0, st_data->base + CLKDRVSTR2, OSCOUT1CLK25MHZ, 3, 0, NULL);
  48
  49         clk_set_parent(hws[ST_CLK_MUX]->clk, hws[ST_CLK_25M]->clk);
  50
  51         hws[ST_CLK_GATE] = clk_hw_register_gate(NULL, "oscout1", "oscout1_mux",
  52                 0, st_data->base + MISCCLKCNTL1, OSCCLKENB,
  53                 CLK_GATE_SET_TO_DISABLE, NULL);
  54
  55         clk_hw_register_clkdev(hws[ST_CLK_GATE], "oscout1", NULL);
  56
  57         return 0;
  58 }
  59
  60 static int st_clk_remove(struct platform_device *pdev)
  61 {
  62         int i;
  63
  64         for (i = 0; i < ST_MAX_CLKS; i++)
  65                 clk_hw_unregister(hws[i]);
  66         return 0;
  67 }
  68
  69 static struct platform_driver st_clk_driver = {
  70         .driver = {
  71                 .name = "clk-st",
  72                 .suppress_bind_attrs = true,
  73         },
  74         .probe = st_clk_probe,
  75         .remove = st_clk_remove,
  76 };
  77 builtin_platform_driver(st_clk_driver);