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

   1 /*
   2  * Marvell Armada 37xx SoC Time Base Generator clocks
   3  *
   4  * Copyright (C) 2016 Marvell
   5  *
   6  * Gregory CLEMENT <gregory.clement@free-electrons.com>
   7  *
   8  * This file is licensed under the terms of the GNU General Public
   9  * License version 2 or later. This program is licensed "as is"
  10  * without any warranty of any kind, whether express or implied.
  11  */
  12
  13 #include <linux/clk-provider.h>
  14 #include <linux/clk.h>
  15 #include <linux/of.h>
  16 #include <linux/of_address.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/slab.h>
  19
  20 #define NUM_TBG     4
  21
  22 #define TBG_CTRL0               0x4
  23 #define TBG_CTRL1               0x8
  24 #define TBG_CTRL7               0x20
  25 #define TBG_CTRL8               0x30
  26
  27 #define TBG_DIV_MASK            0x1FF
  28
  29 #define TBG_A_REFDIV            0
  30 #define TBG_B_REFDIV            16
  31
  32 #define TBG_A_FBDIV             2
  33 #define TBG_B_FBDIV             18
  34
  35 #define TBG_A_VCODIV_SE         0
  36 #define TBG_B_VCODIV_SE         16
  37
  38 #define TBG_A_VCODIV_DIFF       1
  39 #define TBG_B_VCODIV_DIFF       17
  40
  41 struct tbg_def {
  42         char *name;
  43         u32 refdiv_offset;
  44         u32 fbdiv_offset;
  45         u32 vcodiv_reg;
  46         u32 vcodiv_offset;
  47 };
  48
  49 static const struct tbg_def tbg[NUM_TBG] = {
  50         {"TBG-A-P", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL8, TBG_A_VCODIV_DIFF},
  51         {"TBG-B-P", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL8, TBG_B_VCODIV_DIFF},
  52         {"TBG-A-S", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL1, TBG_A_VCODIV_SE},
  53         {"TBG-B-S", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL1, TBG_B_VCODIV_SE},
  54 };
  55
  56 static unsigned int tbg_get_mult(void __iomem *reg, const struct tbg_def *ptbg)
  57 {
  58         u32 val;
  59
  60         val = readl(reg + TBG_CTRL0);
  61
  62         return ((val >> ptbg->fbdiv_offset) & TBG_DIV_MASK) << 2;
  63 }
  64
  65 static unsigned int tbg_get_div(void __iomem *reg, const struct tbg_def *ptbg)
  66 {
  67         u32 val;
  68         unsigned int div;
  69
  70         val = readl(reg + TBG_CTRL7);
  71
  72         div = (val >> ptbg->refdiv_offset) & TBG_DIV_MASK;
  73         if (div == 0)
  74                 div = 1;
  75         val = readl(reg + ptbg->vcodiv_reg);
  76
  77         div *= 1 << ((val >>  ptbg->vcodiv_offset) & TBG_DIV_MASK);
  78
  79         return div;
  80 }
  81
  82
  83 static int armada_3700_tbg_clock_probe(struct platform_device *pdev)
  84 {
  85         struct device_node *np = pdev->dev.of_node;
  86         struct clk_hw_onecell_data *hw_tbg_data;
  87         struct device *dev = &pdev->dev;
  88         const char *parent_name;
  89         struct resource *res;
  90         struct clk *parent;
  91         void __iomem *reg;
  92         int i, ret;
  93
  94         hw_tbg_data = devm_kzalloc(&pdev->dev, sizeof(*hw_tbg_data)
  95                                    + sizeof(*hw_tbg_data->hws) * NUM_TBG,
  96                                    GFP_KERNEL);
  97         if (!hw_tbg_data)
  98                 return -ENOMEM;
  99         hw_tbg_data->num = NUM_TBG;
 100         platform_set_drvdata(pdev, hw_tbg_data);
 101
 102         parent = devm_clk_get(dev, NULL);
 103         if (IS_ERR(parent)) {
 104                 dev_err(dev, "Could get the clock parent\n");
 105                 return -EINVAL;
 106         }
 107         parent_name = __clk_get_name(parent);
 108
 109         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 110         reg = devm_ioremap_resource(dev, res);
 111         if (IS_ERR(reg))
 112                 return PTR_ERR(reg);
 113
 114         for (i = 0; i < NUM_TBG; i++) {
 115                 const char *name;
 116                 unsigned int mult, div;
 117
 118                 name = tbg[i].name;
 119                 mult = tbg_get_mult(reg, &tbg[i]);
 120                 div = tbg_get_div(reg, &tbg[i]);
 121                 hw_tbg_data->hws[i] = clk_hw_register_fixed_factor(NULL, name,
 122                                                 parent_name, 0, mult, div);
 123                 if (IS_ERR(hw_tbg_data->hws[i]))
 124                         dev_err(dev, "Can't register TBG clock %s\n", name);
 125         }
 126
 127         ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, hw_tbg_data);
 128
 129         return ret;
 130 }
 131
 132 static int armada_3700_tbg_clock_remove(struct platform_device *pdev)
 133 {
 134         int i;
 135         struct clk_hw_onecell_data *hw_tbg_data = platform_get_drvdata(pdev);
 136
 137         of_clk_del_provider(pdev->dev.of_node);
 138         for (i = 0; i < hw_tbg_data->num; i++)
 139                 clk_hw_unregister_fixed_factor(hw_tbg_data->hws[i]);
 140
 141         return 0;
 142 }
 143
 144 static const struct of_device_id armada_3700_tbg_clock_of_match[] = {
 145         { .compatible = "marvell,armada-3700-tbg-clock", },
 146         { }
 147 };
 148
 149 static struct platform_driver armada_3700_tbg_clock_driver = {
 150         .probe = armada_3700_tbg_clock_probe,
 151         .remove = armada_3700_tbg_clock_remove,
 152         .driver         = {
 153                 .name   = "marvell-armada-3700-tbg-clock",
 154                 .of_match_table = armada_3700_tbg_clock_of_match,
 155         },
 156 };
 157
 158 builtin_platform_driver(armada_3700_tbg_clock_driver);