drivers/clk/sunxi/clk-mod0.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2013 Emilio López
   4  *
   5  * Emilio López <emilio@elopez.com.ar>
   6  */
   7
   8 #include <linux/clk.h>
   9 #include <linux/clk-provider.h>
  10 #include <linux/io.h>
  11 #include <linux/of_address.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/slab.h>
  14
  15 #include "clk-factors.h"
  16
  17 /**
  18  * sun4i_a10_get_mod0_factors() - calculates m, n factors for MOD0-style clocks
  19  * MOD0 rate is calculated as follows
  20  * rate = (parent_rate >> p) / (m + 1);
  21  */
  22
  23 static void sun4i_a10_get_mod0_factors(struct factors_request *req)
  24 {
  25         u8 div, calcm, calcp;
  26
  27         /* These clocks can only divide, so we will never be able to achieve
  28          * frequencies higher than the parent frequency */
  29         if (req->rate > req->parent_rate)
  30                 req->rate = req->parent_rate;
  31
  32         div = DIV_ROUND_UP(req->parent_rate, req->rate);
  33
  34         if (div < 16)
  35                 calcp = 0;
  36         else if (div / 2 < 16)
  37                 calcp = 1;
  38         else if (div / 4 < 16)
  39                 calcp = 2;
  40         else
  41                 calcp = 3;
  42
  43         calcm = DIV_ROUND_UP(div, 1 << calcp);
  44
  45         req->rate = (req->parent_rate >> calcp) / calcm;
  46         req->m = calcm - 1;
  47         req->p = calcp;
  48 }
  49
  50 /* user manual says "n" but it's really "p" */
  51 static const struct clk_factors_config sun4i_a10_mod0_config = {
  52         .mshift = 0,
  53         .mwidth = 4,
  54         .pshift = 16,
  55         .pwidth = 2,
  56 };
  57
  58 static const struct factors_data sun4i_a10_mod0_data = {
  59         .enable = 31,
  60         .mux = 24,
  61         .muxmask = BIT(1) | BIT(0),
  62         .table = &sun4i_a10_mod0_config,
  63         .getter = sun4i_a10_get_mod0_factors,
  64 };
  65
  66 static DEFINE_SPINLOCK(sun4i_a10_mod0_lock);
  67
  68 static void __init sun4i_a10_mod0_setup(struct device_node *node)
  69 {
  70         void __iomem *reg;
  71
  72         reg = of_iomap(node, 0);
  73         if (!reg) {
  74                 /*
  75                  * This happens with mod0 clk nodes instantiated through
  76                  * mfd, as those do not have their resources assigned at
  77                  * CLK_OF_DECLARE time yet, so do not print an error.
  78                  */
  79                 return;
  80         }
  81
  82         sunxi_factors_register(node, &sun4i_a10_mod0_data,
  83                                &sun4i_a10_mod0_lock, reg);
  84 }
  85 CLK_OF_DECLARE_DRIVER(sun4i_a10_mod0, "allwinner,sun4i-a10-mod0-clk",
  86                       sun4i_a10_mod0_setup);
  87
  88 static int sun4i_a10_mod0_clk_probe(struct platform_device *pdev)
  89 {
  90         struct device_node *np = pdev->dev.of_node;
  91         struct resource *r;
  92         void __iomem *reg;
  93
  94         if (!np)
  95                 return -ENODEV;
  96
  97         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  98         reg = devm_ioremap_resource(&pdev->dev, r);
  99         if (IS_ERR(reg))
 100                 return PTR_ERR(reg);
 101
 102         sunxi_factors_register(np, &sun4i_a10_mod0_data,
 103                                &sun4i_a10_mod0_lock, reg);
 104         return 0;
 105 }
 106
 107 static const struct of_device_id sun4i_a10_mod0_clk_dt_ids[] = {
 108         { .compatible = "allwinner,sun4i-a10-mod0-clk" },
 109         { /* sentinel */ }
 110 };
 111
 112 static struct platform_driver sun4i_a10_mod0_clk_driver = {
 113         .driver = {
 114                 .name = "sun4i-a10-mod0-clk",
 115                 .of_match_table = sun4i_a10_mod0_clk_dt_ids,
 116         },
 117         .probe = sun4i_a10_mod0_clk_probe,
 118 };
 119 builtin_platform_driver(sun4i_a10_mod0_clk_driver);
 120
 121 static const struct factors_data sun9i_a80_mod0_data __initconst = {
 122         .enable = 31,
 123         .mux = 24,
 124         .muxmask = BIT(3) | BIT(2) | BIT(1) | BIT(0),
 125         .table = &sun4i_a10_mod0_config,
 126         .getter = sun4i_a10_get_mod0_factors,
 127 };
 128
 129 static void __init sun9i_a80_mod0_setup(struct device_node *node)
 130 {
 131         void __iomem *reg;
 132
 133         reg = of_io_request_and_map(node, 0, of_node_full_name(node));
 134         if (IS_ERR(reg)) {
 135                 pr_err("Could not get registers for mod0-clk: %pOFn\n",
 136                        node);
 137                 return;
 138         }
 139
 140         sunxi_factors_register(node, &sun9i_a80_mod0_data,
 141                                &sun4i_a10_mod0_lock, reg);
 142 }
 143 CLK_OF_DECLARE(sun9i_a80_mod0, "allwinner,sun9i-a80-mod0-clk", sun9i_a80_mod0_setup);
 144
 145 static DEFINE_SPINLOCK(sun5i_a13_mbus_lock);
 146
 147 static void __init sun5i_a13_mbus_setup(struct device_node *node)
 148 {
 149         void __iomem *reg;
 150
 151         reg = of_iomap(node, 0);
 152         if (!reg) {
 153                 pr_err("Could not get registers for a13-mbus-clk\n");
 154                 return;
 155         }
 156
 157         /* The MBUS clocks needs to be always enabled */
 158         sunxi_factors_register_critical(node, &sun4i_a10_mod0_data,
 159                                         &sun5i_a13_mbus_lock, reg);
 160 }
 161 CLK_OF_DECLARE(sun5i_a13_mbus, "allwinner,sun5i-a13-mbus-clk", sun5i_a13_mbus_setup);
 162
 163 struct mmc_phase {
 164         struct clk_hw           hw;
 165         u8                      offset;
 166         void __iomem            *reg;
 167         spinlock_t              *lock;
 168 };
 169
 170 #define to_mmc_phase(_hw) container_of(_hw, struct mmc_phase, hw)
 171
 172 static int mmc_get_phase(struct clk_hw *hw)
 173 {
 174         struct clk *mmc, *mmc_parent, *clk = hw->clk;
 175         struct mmc_phase *phase = to_mmc_phase(hw);
 176         unsigned int mmc_rate, mmc_parent_rate;
 177         u16 step, mmc_div;
 178         u32 value;
 179         u8 delay;
 180
 181         value = readl(phase->reg);
 182         delay = (value >> phase->offset) & 0x3;
 183
 184         if (!delay)
 185                 return 180;
 186
 187         /* Get the main MMC clock */
 188         mmc = clk_get_parent(clk);
 189         if (!mmc)
 190                 return -EINVAL;
 191
 192         /* And its rate */
 193         mmc_rate = clk_get_rate(mmc);
 194         if (!mmc_rate)
 195                 return -EINVAL;
 196
 197         /* Now, get the MMC parent (most likely some PLL) */
 198         mmc_parent = clk_get_parent(mmc);
 199         if (!mmc_parent)
 200                 return -EINVAL;
 201
 202         /* And its rate */
 203         mmc_parent_rate = clk_get_rate(mmc_parent);
 204         if (!mmc_parent_rate)
 205                 return -EINVAL;
 206
 207         /* Get MMC clock divider */
 208         mmc_div = mmc_parent_rate / mmc_rate;
 209
 210         step = DIV_ROUND_CLOSEST(360, mmc_div);
 211         return delay * step;
 212 }
 213
 214 static int mmc_set_phase(struct clk_hw *hw, int degrees)
 215 {
 216         struct clk *mmc, *mmc_parent, *clk = hw->clk;
 217         struct mmc_phase *phase = to_mmc_phase(hw);
 218         unsigned int mmc_rate, mmc_parent_rate;
 219         unsigned long flags;
 220         u32 value;
 221         u8 delay;
 222
 223         /* Get the main MMC clock */
 224         mmc = clk_get_parent(clk);
 225         if (!mmc)
 226                 return -EINVAL;
 227
 228         /* And its rate */
 229         mmc_rate = clk_get_rate(mmc);
 230         if (!mmc_rate)
 231                 return -EINVAL;
 232
 233         /* Now, get the MMC parent (most likely some PLL) */
 234         mmc_parent = clk_get_parent(mmc);
 235         if (!mmc_parent)
 236                 return -EINVAL;
 237
 238         /* And its rate */
 239         mmc_parent_rate = clk_get_rate(mmc_parent);
 240         if (!mmc_parent_rate)
 241                 return -EINVAL;
 242
 243         if (degrees != 180) {
 244                 u16 step, mmc_div;
 245
 246                 /* Get MMC clock divider */
 247                 mmc_div = mmc_parent_rate / mmc_rate;
 248
 249                 /*
 250                  * We can only outphase the clocks by multiple of the
 251                  * PLL's period.
 252                  *
 253                  * Since the MMC clock in only a divider, and the
 254                  * formula to get the outphasing in degrees is deg =
 255                  * 360 * delta / period
 256                  *
 257                  * If we simplify this formula, we can see that the
 258                  * only thing that we're concerned about is the number
 259                  * of period we want to outphase our clock from, and
 260                  * the divider set by the MMC clock.
 261                  */
 262                 step = DIV_ROUND_CLOSEST(360, mmc_div);
 263                 delay = DIV_ROUND_CLOSEST(degrees, step);
 264         } else {
 265                 delay = 0;
 266         }
 267
 268         spin_lock_irqsave(phase->lock, flags);
 269         value = readl(phase->reg);
 270         value &= ~GENMASK(phase->offset + 3, phase->offset);
 271         value |= delay << phase->offset;
 272         writel(value, phase->reg);
 273         spin_unlock_irqrestore(phase->lock, flags);
 274
 275         return 0;
 276 }
 277
 278 static const struct clk_ops mmc_clk_ops = {
 279         .get_phase      = mmc_get_phase,
 280         .set_phase      = mmc_set_phase,
 281 };
 282
 283 /*
 284  * sunxi_mmc_setup - Common setup function for mmc module clocks
 285  *
 286  * The only difference between module clocks on different platforms is the
 287  * width of the mux register bits and the valid values, which are passed in
 288  * through struct factors_data. The phase clocks parts are identical.
 289  */
 290 static void __init sunxi_mmc_setup(struct device_node *node,
 291                                    const struct factors_data *data,
 292                                    spinlock_t *lock)
 293 {
 294         struct clk_onecell_data *clk_data;
 295         const char *parent;
 296         void __iomem *reg;
 297         int i;
 298
 299         reg = of_io_request_and_map(node, 0, of_node_full_name(node));
 300         if (IS_ERR(reg)) {
 301                 pr_err("Couldn't map the %pOFn clock registers\n", node);
 302                 return;
 303         }
 304
 305         clk_data = kmalloc(sizeof(*clk_data), GFP_KERNEL);
 306         if (!clk_data)
 307                 return;
 308
 309         clk_data->clks = kcalloc(3, sizeof(*clk_data->clks), GFP_KERNEL);
 310         if (!clk_data->clks)
 311                 goto err_free_data;
 312
 313         clk_data->clk_num = 3;
 314         clk_data->clks[0] = sunxi_factors_register(node, data, lock, reg);
 315         if (!clk_data->clks[0])
 316                 goto err_free_clks;
 317
 318         parent = __clk_get_name(clk_data->clks[0]);
 319
 320         for (i = 1; i < 3; i++) {
 321                 struct clk_init_data init = {
 322                         .num_parents    = 1,
 323                         .parent_names   = &parent,
 324                         .ops            = &mmc_clk_ops,
 325                 };
 326                 struct mmc_phase *phase;
 327
 328                 phase = kmalloc(sizeof(*phase), GFP_KERNEL);
 329                 if (!phase)
 330                         continue;
 331
 332                 phase->hw.init = &init;
 333                 phase->reg = reg;
 334                 phase->lock = lock;
 335
 336                 if (i == 1)
 337                         phase->offset = 8;
 338                 else
 339                         phase->offset = 20;
 340
 341                 if (of_property_read_string_index(node, "clock-output-names",
 342                                                   i, &init.name))
 343                         init.name = node->name;
 344
 345                 clk_data->clks[i] = clk_register(NULL, &phase->hw);
 346                 if (IS_ERR(clk_data->clks[i])) {
 347                         kfree(phase);
 348                         continue;
 349                 }
 350         }
 351
 352         of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
 353
 354         return;
 355
 356 err_free_clks:
 357         kfree(clk_data->clks);
 358 err_free_data:
 359         kfree(clk_data);
 360 }
 361
 362 static DEFINE_SPINLOCK(sun4i_a10_mmc_lock);
 363
 364 static void __init sun4i_a10_mmc_setup(struct device_node *node)
 365 {
 366         sunxi_mmc_setup(node, &sun4i_a10_mod0_data, &sun4i_a10_mmc_lock);
 367 }
 368 CLK_OF_DECLARE(sun4i_a10_mmc, "allwinner,sun4i-a10-mmc-clk", sun4i_a10_mmc_setup);
 369
 370 static DEFINE_SPINLOCK(sun9i_a80_mmc_lock);
 371
 372 static void __init sun9i_a80_mmc_setup(struct device_node *node)
 373 {
 374         sunxi_mmc_setup(node, &sun9i_a80_mod0_data, &sun9i_a80_mmc_lock);
 375 }
 376 CLK_OF_DECLARE(sun9i_a80_mmc, "allwinner,sun9i-a80-mmc-clk", sun9i_a80_mmc_setup);