drivers/clk/sunxi/clk-sun4i-display.c

   1 /*
   2  * Copyright 2015 Maxime Ripard
   3  *
   4  * Maxime Ripard <maxime.ripard@free-electrons.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/clk-provider.h>
  18 #include <linux/kernel.h>
  19 #include <linux/of_address.h>
  20 #include <linux/reset-controller.h>
  21 #include <linux/slab.h>
  22 #include <linux/spinlock.h>
  23
  24 struct sun4i_a10_display_clk_data {
  25         bool    has_div;
  26         u8      num_rst;
  27         u8      parents;
  28
  29         u8      offset_en;
  30         u8      offset_div;
  31         u8      offset_mux;
  32         u8      offset_rst;
  33
  34         u8      width_div;
  35         u8      width_mux;
  36 };
  37
  38 struct reset_data {
  39         void __iomem                    *reg;
  40         spinlock_t                      *lock;
  41         struct reset_controller_dev     rcdev;
  42         u8                              offset;
  43 };
  44
  45 static DEFINE_SPINLOCK(sun4i_a10_display_lock);
  46
  47 static inline struct reset_data *rcdev_to_reset_data(struct reset_controller_dev *rcdev)
  48 {
  49         return container_of(rcdev, struct reset_data, rcdev);
  50 };
  51
  52 static int sun4i_a10_display_assert(struct reset_controller_dev *rcdev,
  53                                     unsigned long id)
  54 {
  55         struct reset_data *data = rcdev_to_reset_data(rcdev);
  56         unsigned long flags;
  57         u32 reg;
  58
  59         spin_lock_irqsave(data->lock, flags);
  60
  61         reg = readl(data->reg);
  62         writel(reg & ~BIT(data->offset + id), data->reg);
  63
  64         spin_unlock_irqrestore(data->lock, flags);
  65
  66         return 0;
  67 }
  68
  69 static int sun4i_a10_display_deassert(struct reset_controller_dev *rcdev,
  70                                       unsigned long id)
  71 {
  72         struct reset_data *data = rcdev_to_reset_data(rcdev);
  73         unsigned long flags;
  74         u32 reg;
  75
  76         spin_lock_irqsave(data->lock, flags);
  77
  78         reg = readl(data->reg);
  79         writel(reg | BIT(data->offset + id), data->reg);
  80
  81         spin_unlock_irqrestore(data->lock, flags);
  82
  83         return 0;
  84 }
  85
  86 static int sun4i_a10_display_status(struct reset_controller_dev *rcdev,
  87                                     unsigned long id)
  88 {
  89         struct reset_data *data = rcdev_to_reset_data(rcdev);
  90
  91         return !(readl(data->reg) & BIT(data->offset + id));
  92 }
  93
  94 static const struct reset_control_ops sun4i_a10_display_reset_ops = {
  95         .assert         = sun4i_a10_display_assert,
  96         .deassert       = sun4i_a10_display_deassert,
  97         .status         = sun4i_a10_display_status,
  98 };
  99
 100 static int sun4i_a10_display_reset_xlate(struct reset_controller_dev *rcdev,
 101                                          const struct of_phandle_args *spec)
 102 {
 103         /* We only have a single reset signal */
 104         return 0;
 105 }
 106
 107 static void __init sun4i_a10_display_init(struct device_node *node,
 108                                           const struct sun4i_a10_display_clk_data *data)
 109 {
 110         const char *parents[4];
 111         const char *clk_name = node->name;
 112         struct reset_data *reset_data;
 113         struct clk_divider *div = NULL;
 114         struct clk_gate *gate;
 115         struct resource res;
 116         struct clk_mux *mux;
 117         void __iomem *reg;
 118         struct clk *clk;
 119         int ret;
 120
 121         of_property_read_string(node, "clock-output-names", &clk_name);
 122
 123         reg = of_io_request_and_map(node, 0, of_node_full_name(node));
 124         if (IS_ERR(reg)) {
 125                 pr_err("%s: Could not map the clock registers\n", clk_name);
 126                 return;
 127         }
 128
 129         ret = of_clk_parent_fill(node, parents, data->parents);
 130         if (ret != data->parents) {
 131                 pr_err("%s: Could not retrieve the parents\n", clk_name);
 132                 goto unmap;
 133         }
 134
 135         mux = kzalloc(sizeof(*mux), GFP_KERNEL);
 136         if (!mux)
 137                 goto unmap;
 138
 139         mux->reg = reg;
 140         mux->shift = data->offset_mux;
 141         mux->mask = (1 << data->width_mux) - 1;
 142         mux->lock = &sun4i_a10_display_lock;
 143
 144         gate = kzalloc(sizeof(*gate), GFP_KERNEL);
 145         if (!gate)
 146                 goto free_mux;
 147
 148         gate->reg = reg;
 149         gate->bit_idx = data->offset_en;
 150         gate->lock = &sun4i_a10_display_lock;
 151
 152         if (data->has_div) {
 153                 div = kzalloc(sizeof(*div), GFP_KERNEL);
 154                 if (!div)
 155                         goto free_gate;
 156
 157                 div->reg = reg;
 158                 div->shift = data->offset_div;
 159                 div->width = data->width_div;
 160                 div->lock = &sun4i_a10_display_lock;
 161         }
 162
 163         clk = clk_register_composite(NULL, clk_name,
 164                                      parents, data->parents,
 165                                      &mux->hw, &clk_mux_ops,
 166                                      data->has_div ? &div->hw : NULL,
 167                                      data->has_div ? &clk_divider_ops : NULL,
 168                                      &gate->hw, &clk_gate_ops,
 169                                      0);
 170         if (IS_ERR(clk)) {
 171                 pr_err("%s: Couldn't register the clock\n", clk_name);
 172                 goto free_div;
 173         }
 174
 175         ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 176         if (ret) {
 177                 pr_err("%s: Couldn't register DT provider\n", clk_name);
 178                 goto free_clk;
 179         }
 180
 181         if (!data->num_rst)
 182                 return;
 183
 184         reset_data = kzalloc(sizeof(*reset_data), GFP_KERNEL);
 185         if (!reset_data)
 186                 goto free_of_clk;
 187
 188         reset_data->reg = reg;
 189         reset_data->offset = data->offset_rst;
 190         reset_data->lock = &sun4i_a10_display_lock;
 191         reset_data->rcdev.nr_resets = data->num_rst;
 192         reset_data->rcdev.ops = &sun4i_a10_display_reset_ops;
 193         reset_data->rcdev.of_node = node;
 194
 195         if (data->num_rst == 1) {
 196                 reset_data->rcdev.of_reset_n_cells = 0;
 197                 reset_data->rcdev.of_xlate = &sun4i_a10_display_reset_xlate;
 198         } else {
 199                 reset_data->rcdev.of_reset_n_cells = 1;
 200         }
 201
 202         if (reset_controller_register(&reset_data->rcdev)) {
 203                 pr_err("%s: Couldn't register the reset controller\n",
 204                        clk_name);
 205                 goto free_reset;
 206         }
 207
 208         return;
 209
 210 free_reset:
 211         kfree(reset_data);
 212 free_of_clk:
 213         of_clk_del_provider(node);
 214 free_clk:
 215         clk_unregister_composite(clk);
 216 free_div:
 217         kfree(div);
 218 free_gate:
 219         kfree(gate);
 220 free_mux:
 221         kfree(mux);
 222 unmap:
 223         iounmap(reg);
 224         of_address_to_resource(node, 0, &res);
 225         release_mem_region(res.start, resource_size(&res));
 226 }
 227
 228 static const struct sun4i_a10_display_clk_data sun4i_a10_tcon_ch0_data __initconst = {
 229         .num_rst        = 2,
 230         .parents        = 4,
 231         .offset_en      = 31,
 232         .offset_rst     = 29,
 233         .offset_mux     = 24,
 234         .width_mux      = 2,
 235 };
 236
 237 static void __init sun4i_a10_tcon_ch0_setup(struct device_node *node)
 238 {
 239         sun4i_a10_display_init(node, &sun4i_a10_tcon_ch0_data);
 240 }
 241 CLK_OF_DECLARE(sun4i_a10_tcon_ch0, "allwinner,sun4i-a10-tcon-ch0-clk",
 242                sun4i_a10_tcon_ch0_setup);
 243
 244 static const struct sun4i_a10_display_clk_data sun4i_a10_display_data __initconst = {
 245         .has_div        = true,
 246         .num_rst        = 1,
 247         .parents        = 3,
 248         .offset_en      = 31,
 249         .offset_rst     = 30,
 250         .offset_mux     = 24,
 251         .offset_div     = 0,
 252         .width_mux      = 2,
 253         .width_div      = 4,
 254 };
 255
 256 static void __init sun4i_a10_display_setup(struct device_node *node)
 257 {
 258         sun4i_a10_display_init(node, &sun4i_a10_display_data);
 259 }
 260 CLK_OF_DECLARE(sun4i_a10_display, "allwinner,sun4i-a10-display-clk",
 261                sun4i_a10_display_setup);