drivers/clk/mvebu/armada-37xx-tbg.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Marvell Armada 37xx SoC Time Base Generator clocks
   4  *
   5  * Marek Behun <marek.behun@nic.cz>
   6  *
   7  * Based on Linux driver by:
   8  *   Gregory CLEMENT <gregory.clement@free-electrons.com>
   9  */
  10
  11 #include <common.h>
  12 #include <clk-uclass.h>
  13 #include <clk.h>
  14 #include <dm.h>
  15 #include <asm/io.h>
  16 #include <asm/arch/cpu.h>
  17
  18 #define NUM_TBG     4
  19
  20 #define TBG_CTRL0               0x4
  21 #define TBG_CTRL1               0x8
  22 #define TBG_CTRL7               0x20
  23 #define TBG_CTRL8               0x30
  24
  25 #define TBG_DIV_MASK            0x1FF
  26
  27 #define TBG_A_REFDIV            0
  28 #define TBG_B_REFDIV            16
  29
  30 #define TBG_A_FBDIV             2
  31 #define TBG_B_FBDIV             18
  32
  33 #define TBG_A_VCODIV_SE         0
  34 #define TBG_B_VCODIV_SE         16
  35
  36 #define TBG_A_VCODIV_DIFF       1
  37 #define TBG_B_VCODIV_DIFF       17
  38
  39 struct tbg_def {
  40         const char *name;
  41         u32 refdiv_offset;
  42         u32 fbdiv_offset;
  43         u32 vcodiv_reg;
  44         u32 vcodiv_offset;
  45 };
  46
  47 static const struct tbg_def tbg[NUM_TBG] = {
  48         {"TBG-A-P", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL8, TBG_A_VCODIV_DIFF},
  49         {"TBG-B-P", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL8, TBG_B_VCODIV_DIFF},
  50         {"TBG-A-S", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL1, TBG_A_VCODIV_SE},
  51         {"TBG-B-S", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL1, TBG_B_VCODIV_SE},
  52 };
  53
  54 struct a37xx_tbgclk {
  55         ulong rates[NUM_TBG];
  56         unsigned int mult[NUM_TBG];
  57         unsigned int div[NUM_TBG];
  58 };
  59
  60 static unsigned int tbg_get_mult(void __iomem *reg, const struct tbg_def *ptbg)
  61 {
  62         u32 val;
  63
  64         val = readl(reg + TBG_CTRL0);
  65
  66         return ((val >> ptbg->fbdiv_offset) & TBG_DIV_MASK) << 2;
  67 }
  68
  69 static unsigned int tbg_get_div(void __iomem *reg, const struct tbg_def *ptbg)
  70 {
  71         u32 val;
  72         unsigned int div;
  73
  74         val = readl(reg + TBG_CTRL7);
  75
  76         div = (val >> ptbg->refdiv_offset) & TBG_DIV_MASK;
  77         if (div == 0)
  78                 div = 1;
  79         val = readl(reg + ptbg->vcodiv_reg);
  80
  81         div *= 1 << ((val >>  ptbg->vcodiv_offset) & TBG_DIV_MASK);
  82
  83         return div;
  84 }
  85
  86 static ulong armada_37xx_tbg_clk_get_rate(struct clk *clk)
  87 {
  88         struct a37xx_tbgclk *priv = dev_get_priv(clk->dev);
  89
  90         if (clk->id >= NUM_TBG)
  91                 return -ENODEV;
  92
  93         return priv->rates[clk->id];
  94 }
  95
  96 #if defined(CONFIG_CMD_CLK) && defined(CONFIG_CLK_ARMADA_3720)
  97 int armada_37xx_tbg_clk_dump(struct udevice *dev)
  98 {
  99         struct a37xx_tbgclk *priv = dev_get_priv(dev);
 100         int i;
 101
 102         for (i = 0; i < NUM_TBG; ++i)
 103                 printf("  %s at %lu Hz\n", tbg[i].name,
 104                        priv->rates[i]);
 105         printf("\n");
 106
 107         return 0;
 108 }
 109 #endif
 110
 111 static int armada_37xx_tbg_clk_probe(struct udevice *dev)
 112 {
 113         struct a37xx_tbgclk *priv = dev_get_priv(dev);
 114         void __iomem *reg;
 115         ulong xtal;
 116         int i;
 117
 118         reg = dev_read_addr_ptr(dev);
 119         if (!reg) {
 120                 dev_err(dev, "no io address\n");
 121                 return -ENODEV;
 122         }
 123
 124         xtal = (ulong)get_ref_clk() * 1000000;
 125
 126         for (i = 0; i < NUM_TBG; ++i) {
 127                 unsigned int mult, div;
 128
 129                 mult = tbg_get_mult(reg, &tbg[i]);
 130                 div = tbg_get_div(reg, &tbg[i]);
 131
 132                 priv->rates[i] = (xtal * mult) / div;
 133         }
 134
 135         return 0;
 136 }
 137
 138 static const struct clk_ops armada_37xx_tbg_clk_ops = {
 139         .get_rate = armada_37xx_tbg_clk_get_rate,
 140 };
 141
 142 static const struct udevice_id armada_37xx_tbg_clk_ids[] = {
 143         { .compatible = "marvell,armada-3700-tbg-clock" },
 144         {}
 145 };
 146
 147 U_BOOT_DRIVER(armada_37xx_tbg_clk) = {
 148         .name           = "armada_37xx_tbg_clk",
 149         .id             = UCLASS_CLK,
 150         .of_match       = armada_37xx_tbg_clk_ids,
 151         .ops            = &armada_37xx_tbg_clk_ops,
 152         .priv_auto_alloc_size = sizeof(struct a37xx_tbgclk),
 153         .probe          = armada_37xx_tbg_clk_probe,
 154 };