drivers/clk/x86/clk-fch.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-fch.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 #define RV_CLK_48M      0
  30 #define RV_CLK_GATE     1
  31 #define RV_MAX_CLKS     2
  32
  33 static const char * const clk_oscout1_parents[] = { "clk48MHz", "clk25MHz" };
  34 static struct clk_hw *hws[ST_MAX_CLKS];
  35
  36 static int fch_clk_probe(struct platform_device *pdev)
  37 {
  38         struct fch_clk_data *fch_data;
  39
  40         fch_data = dev_get_platdata(&pdev->dev);
  41         if (!fch_data || !fch_data->base)
  42                 return -EINVAL;
  43
  44         if (!fch_data->is_rv) {
  45                 hws[ST_CLK_48M] = clk_hw_register_fixed_rate(NULL, "clk48MHz",
  46                         NULL, 0, 48000000);
  47                 hws[ST_CLK_25M] = clk_hw_register_fixed_rate(NULL, "clk25MHz",
  48                         NULL, 0, 25000000);
  49
  50                 hws[ST_CLK_MUX] = clk_hw_register_mux(NULL, "oscout1_mux",
  51                         clk_oscout1_parents, ARRAY_SIZE(clk_oscout1_parents),
  52                         0, fch_data->base + CLKDRVSTR2, OSCOUT1CLK25MHZ, 3, 0,
  53                         NULL);
  54
  55                 clk_set_parent(hws[ST_CLK_MUX]->clk, hws[ST_CLK_48M]->clk);
  56
  57                 hws[ST_CLK_GATE] = clk_hw_register_gate(NULL, "oscout1",
  58                         "oscout1_mux", 0, fch_data->base + MISCCLKCNTL1,
  59                         OSCCLKENB, CLK_GATE_SET_TO_DISABLE, NULL);
  60
  61                 devm_clk_hw_register_clkdev(&pdev->dev, hws[ST_CLK_GATE],
  62                         "oscout1", NULL);
  63         } else {
  64                 hws[RV_CLK_48M] = clk_hw_register_fixed_rate(NULL, "clk48MHz",
  65                         NULL, 0, 48000000);
  66
  67                 hws[RV_CLK_GATE] = clk_hw_register_gate(NULL, "oscout1",
  68                         "clk48MHz", 0, fch_data->base + MISCCLKCNTL1,
  69                         OSCCLKENB, CLK_GATE_SET_TO_DISABLE, NULL);
  70
  71                 devm_clk_hw_register_clkdev(&pdev->dev, hws[RV_CLK_GATE],
  72                         "oscout1", NULL);
  73         }
  74
  75         return 0;
  76 }
  77
  78 static int fch_clk_remove(struct platform_device *pdev)
  79 {
  80         int i, clks;
  81         struct fch_clk_data *fch_data;
  82
  83         fch_data = dev_get_platdata(&pdev->dev);
  84
  85         clks = fch_data->is_rv ? RV_MAX_CLKS : ST_MAX_CLKS;
  86
  87         for (i = 0; i < clks; i++)
  88                 clk_hw_unregister(hws[i]);
  89
  90         return 0;
  91 }
  92
  93 static struct platform_driver fch_clk_driver = {
  94         .driver = {
  95                 .name = "clk-fch",
  96                 .suppress_bind_attrs = true,
  97         },
  98         .probe = fch_clk_probe,
  99         .remove = fch_clk_remove,
 100 };
 101 builtin_platform_driver(fch_clk_driver);