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         u32     flags;
  38 };
  39
  40 struct reset_data {
  41         void __iomem                    *reg;
  42         spinlock_t                      *lock;
  43         struct reset_controller_dev     rcdev;
  44         u8                              offset;
  45 };
  46
  47 static DEFINE_SPINLOCK(sun4i_a10_display_lock);
  48
  49 static inline struct reset_data *rcdev_to_reset_data(struct reset_controller_dev *rcdev)
  50 {
  51         return container_of(rcdev, struct reset_data, rcdev);
  52 };
  53
  54 static int sun4i_a10_display_assert(struct reset_controller_dev *rcdev,
  55                                     unsigned long id)
  56 {
  57         struct reset_data *data = rcdev_to_reset_data(rcdev);
  58         unsigned long flags;
  59         u32 reg;
  60
  61         spin_lock_irqsave(data->lock, flags);
  62
  63         reg = readl(data->reg);
  64         writel(reg & ~BIT(data->offset + id), data->reg);
  65
  66         spin_unlock_irqrestore(data->lock, flags);
  67
  68         return 0;
  69 }
  70
  71 static int sun4i_a10_display_deassert(struct reset_controller_dev *rcdev,
  72                                       unsigned long id)
  73 {
  74         struct reset_data *data = rcdev_to_reset_data(rcdev);
  75         unsigned long flags;
  76         u32 reg;
  77
  78         spin_lock_irqsave(data->lock, flags);
  79
  80         reg = readl(data->reg);
  81         writel(reg | BIT(data->offset + id), data->reg);
  82
  83         spin_unlock_irqrestore(data->lock, flags);
  84
  85         return 0;
  86 }
  87
  88 static int sun4i_a10_display_status(struct reset_controller_dev *rcdev,
  89                                     unsigned long id)
  90 {
  91         struct reset_data *data = rcdev_to_reset_data(rcdev);
  92
  93         return !(readl(data->reg) & BIT(data->offset + id));
  94 }
  95
  96 static const struct reset_control_ops sun4i_a10_display_reset_ops = {
  97         .assert         = sun4i_a10_display_assert,
  98         .deassert       = sun4i_a10_display_deassert,
  99         .status         = sun4i_a10_display_status,
 100 };
 101
 102 static int sun4i_a10_display_reset_xlate(struct reset_controller_dev *rcdev,
 103                                          const struct of_phandle_args *spec)
 104 {
 105         /* We only have a single reset signal */
 106         return 0;
 107 }
 108
 109 static void __init sun4i_a10_display_init(struct device_node *node,
 110                                           const struct sun4i_a10_display_clk_data *data)
 111 {
 112         const char *parents[4];
 113         const char *clk_name = node->name;
 114         struct reset_data *reset_data;
 115         struct clk_divider *div = NULL;
 116         struct clk_gate *gate;
 117         struct resource res;
 118         struct clk_mux *mux;
 119         void __iomem *reg;
 120         struct clk *clk;
 121         int ret;
 122
 123         of_property_read_string(node, "clock-output-names", &clk_name);
 124
 125         reg = of_io_request_and_map(node, 0, of_node_full_name(node));
 126         if (IS_ERR(reg)) {
 127                 pr_err("%s: Could not map the clock registers\n", clk_name);
 128                 return;
 129         }
 130
 131         ret = of_clk_parent_fill(node, parents, data->parents);
 132         if (ret != data->parents) {
 133                 pr_err("%s: Could not retrieve the parents\n", clk_name);
 134                 goto unmap;
 135         }
 136
 137         mux = kzalloc(sizeof(*mux), GFP_KERNEL);
 138         if (!mux)
 139                 goto unmap;
 140
 141         mux->reg = reg;
 142         mux->shift = data->offset_mux;
 143         mux->mask = (1 << data->width_mux) - 1;
 144         mux->lock = &sun4i_a10_display_lock;
 145
 146         gate = kzalloc(sizeof(*gate), GFP_KERNEL);
 147         if (!gate)
 148                 goto free_mux;
 149
 150         gate->reg = reg;
 151         gate->bit_idx = data->offset_en;
 152         gate->lock = &sun4i_a10_display_lock;
 153
 154         if (data->has_div) {
 155                 div = kzalloc(sizeof(*div), GFP_KERNEL);
 156                 if (!div)
 157                         goto free_gate;
 158
 159                 div->reg = reg;
 160                 div->shift = data->offset_div;
 161                 div->width = data->width_div;
 162                 div->lock = &sun4i_a10_display_lock;
 163         }
 164
 165         clk = clk_register_composite(NULL, clk_name,
 166                                      parents, data->parents,
 167                                      &mux->hw, &clk_mux_ops,
 168                                      data->has_div ? &div->hw : NULL,
 169                                      data->has_div ? &clk_divider_ops : NULL,
 170                                      &gate->hw, &clk_gate_ops,
 171                                      data->flags);
 172         if (IS_ERR(clk)) {
 173                 pr_err("%s: Couldn't register the clock\n", clk_name);
 174                 goto free_div;
 175         }
 176
 177         ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 178         if (ret) {
 179                 pr_err("%s: Couldn't register DT provider\n", clk_name);
 180                 goto free_clk;
 181         }
 182
 183         if (!data->num_rst)
 184                 return;
 185
 186         reset_data = kzalloc(sizeof(*reset_data), GFP_KERNEL);
 187         if (!reset_data)
 188                 goto free_of_clk;
 189
 190         reset_data->reg = reg;
 191         reset_data->offset = data->offset_rst;
 192         reset_data->lock = &sun4i_a10_display_lock;
 193         reset_data->rcdev.nr_resets = data->num_rst;
 194         reset_data->rcdev.ops = &sun4i_a10_display_reset_ops;
 195         reset_data->rcdev.of_node = node;
 196
 197         if (data->num_rst == 1) {
 198                 reset_data->rcdev.of_reset_n_cells = 0;
 199                 reset_data->rcdev.of_xlate = &sun4i_a10_display_reset_xlate;
 200         } else {
 201                 reset_data->rcdev.of_reset_n_cells = 1;
 202         }
 203
 204         if (reset_controller_register(&reset_data->rcdev)) {
 205                 pr_err("%s: Couldn't register the reset controller\n",
 206                        clk_name);
 207                 goto free_reset;
 208         }
 209
 210         return;
 211
 212 free_reset:
 213         kfree(reset_data);
 214 free_of_clk:
 215         of_clk_del_provider(node);
 216 free_clk:
 217         clk_unregister_composite(clk);
 218 free_div:
 219         kfree(div);
 220 free_gate:
 221         kfree(gate);
 222 free_mux:
 223         kfree(mux);
 224 unmap:
 225         iounmap(reg);
 226         of_address_to_resource(node, 0, &res);
 227         release_mem_region(res.start, resource_size(&res));
 228 }
 229
 230 static const struct sun4i_a10_display_clk_data sun4i_a10_tcon_ch0_data __initconst = {
 231         .num_rst        = 2,
 232         .parents        = 4,
 233         .offset_en      = 31,
 234         .offset_rst     = 29,
 235         .offset_mux     = 24,
 236         .width_mux      = 2,
 237         .flags          = CLK_SET_RATE_PARENT,
 238 };
 239
 240 static void __init sun4i_a10_tcon_ch0_setup(struct device_node *node)
 241 {
 242         sun4i_a10_display_init(node, &sun4i_a10_tcon_ch0_data);
 243 }
 244 CLK_OF_DECLARE(sun4i_a10_tcon_ch0, "allwinner,sun4i-a10-tcon-ch0-clk",
 245                sun4i_a10_tcon_ch0_setup);
 246
 247 static const struct sun4i_a10_display_clk_data sun4i_a10_display_data __initconst = {
 248         .has_div        = true,
 249         .num_rst        = 1,
 250         .parents        = 3,
 251         .offset_en      = 31,
 252         .offset_rst     = 30,
 253         .offset_mux     = 24,
 254         .offset_div     = 0,
 255         .width_mux      = 2,
 256         .width_div      = 4,
 257 };
 258
 259 static void __init sun4i_a10_display_setup(struct device_node *node)
 260 {
 261         sun4i_a10_display_init(node, &sun4i_a10_display_data);
 262 }
 263 CLK_OF_DECLARE(sun4i_a10_display, "allwinner,sun4i-a10-display-clk",
 264                sun4i_a10_display_setup);