drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Xilinx 'Clocking Wizard' driver
   4  *
   5  *  Copyright (C) 2013 - 2014 Xilinx
   6  *
   7  *  Sören Brinkmann <soren.brinkmann@xilinx.com>
   8  */
   9
  10 #include <linux/platform_device.h>
  11 #include <linux/clk.h>
  12 #include <linux/clk-provider.h>
  13 #include <linux/slab.h>
  14 #include <linux/io.h>
  15 #include <linux/of.h>
  16 #include <linux/module.h>
  17 #include <linux/err.h>
  18
  19 #define WZRD_NUM_OUTPUTS        7
  20 #define WZRD_ACLK_MAX_FREQ      250000000UL
  21
  22 #define WZRD_CLK_CFG_REG(n)     (0x200 + 4 * (n))
  23
  24 #define WZRD_CLKOUT0_FRAC_EN    BIT(18)
  25 #define WZRD_CLKFBOUT_FRAC_EN   BIT(26)
  26
  27 #define WZRD_CLKFBOUT_MULT_SHIFT        8
  28 #define WZRD_CLKFBOUT_MULT_MASK         (0xff << WZRD_CLKFBOUT_MULT_SHIFT)
  29 #define WZRD_DIVCLK_DIVIDE_SHIFT        0
  30 #define WZRD_DIVCLK_DIVIDE_MASK         (0xff << WZRD_DIVCLK_DIVIDE_SHIFT)
  31 #define WZRD_CLKOUT_DIVIDE_SHIFT        0
  32 #define WZRD_CLKOUT_DIVIDE_MASK         (0xff << WZRD_DIVCLK_DIVIDE_SHIFT)
  33
  34 enum clk_wzrd_int_clks {
  35         wzrd_clk_mul,
  36         wzrd_clk_mul_div,
  37         wzrd_clk_int_max
  38 };
  39
  40 /**
  41  * struct clk_wzrd:
  42  * @clk_data:           Clock data
  43  * @nb:                 Notifier block
  44  * @base:               Memory base
  45  * @clk_in1:            Handle to input clock 'clk_in1'
  46  * @axi_clk:            Handle to input clock 's_axi_aclk'
  47  * @clks_internal:      Internal clocks
  48  * @clkout:             Output clocks
  49  * @speed_grade:        Speed grade of the device
  50  * @suspended:          Flag indicating power state of the device
  51  */
  52 struct clk_wzrd {
  53         struct clk_onecell_data clk_data;
  54         struct notifier_block nb;
  55         void __iomem *base;
  56         struct clk *clk_in1;
  57         struct clk *axi_clk;
  58         struct clk *clks_internal[wzrd_clk_int_max];
  59         struct clk *clkout[WZRD_NUM_OUTPUTS];
  60         unsigned int speed_grade;
  61         bool suspended;
  62 };
  63
  64 #define to_clk_wzrd(_nb) container_of(_nb, struct clk_wzrd, nb)
  65
  66 /* maximum frequencies for input/output clocks per speed grade */
  67 static const unsigned long clk_wzrd_max_freq[] = {
  68         800000000UL,
  69         933000000UL,
  70         1066000000UL
  71 };
  72
  73 static int clk_wzrd_clk_notifier(struct notifier_block *nb, unsigned long event,
  74                                  void *data)
  75 {
  76         unsigned long max;
  77         struct clk_notifier_data *ndata = data;
  78         struct clk_wzrd *clk_wzrd = to_clk_wzrd(nb);
  79
  80         if (clk_wzrd->suspended)
  81                 return NOTIFY_OK;
  82
  83         if (ndata->clk == clk_wzrd->clk_in1)
  84                 max = clk_wzrd_max_freq[clk_wzrd->speed_grade - 1];
  85         else if (ndata->clk == clk_wzrd->axi_clk)
  86                 max = WZRD_ACLK_MAX_FREQ;
  87         else
  88                 return NOTIFY_DONE;     /* should never happen */
  89
  90         switch (event) {
  91         case PRE_RATE_CHANGE:
  92                 if (ndata->new_rate > max)
  93                         return NOTIFY_BAD;
  94                 return NOTIFY_OK;
  95         case POST_RATE_CHANGE:
  96         case ABORT_RATE_CHANGE:
  97         default:
  98                 return NOTIFY_DONE;
  99         }
 100 }
 101
 102 static int __maybe_unused clk_wzrd_suspend(struct device *dev)
 103 {
 104         struct clk_wzrd *clk_wzrd = dev_get_drvdata(dev);
 105
 106         clk_disable_unprepare(clk_wzrd->axi_clk);
 107         clk_wzrd->suspended = true;
 108
 109         return 0;
 110 }
 111
 112 static int __maybe_unused clk_wzrd_resume(struct device *dev)
 113 {
 114         int ret;
 115         struct clk_wzrd *clk_wzrd = dev_get_drvdata(dev);
 116
 117         ret = clk_prepare_enable(clk_wzrd->axi_clk);
 118         if (ret) {
 119                 dev_err(dev, "unable to enable s_axi_aclk\n");
 120                 return ret;
 121         }
 122
 123         clk_wzrd->suspended = false;
 124
 125         return 0;
 126 }
 127
 128 static SIMPLE_DEV_PM_OPS(clk_wzrd_dev_pm_ops, clk_wzrd_suspend,
 129                          clk_wzrd_resume);
 130
 131 static int clk_wzrd_probe(struct platform_device *pdev)
 132 {
 133         int i, ret;
 134         u32 reg;
 135         unsigned long rate;
 136         const char *clk_name;
 137         struct clk_wzrd *clk_wzrd;
 138         struct device_node *np = pdev->dev.of_node;
 139
 140         clk_wzrd = devm_kzalloc(&pdev->dev, sizeof(*clk_wzrd), GFP_KERNEL);
 141         if (!clk_wzrd)
 142                 return -ENOMEM;
 143         platform_set_drvdata(pdev, clk_wzrd);
 144
 145         clk_wzrd->base = devm_platform_ioremap_resource(pdev, 0);
 146         if (IS_ERR(clk_wzrd->base))
 147                 return PTR_ERR(clk_wzrd->base);
 148
 149         ret = of_property_read_u32(np, "speed-grade", &clk_wzrd->speed_grade);
 150         if (!ret) {
 151                 if (clk_wzrd->speed_grade < 1 || clk_wzrd->speed_grade > 3) {
 152                         dev_warn(&pdev->dev, "invalid speed grade '%d'\n",
 153                                  clk_wzrd->speed_grade);
 154                         clk_wzrd->speed_grade = 0;
 155                 }
 156         }
 157
 158         clk_wzrd->clk_in1 = devm_clk_get(&pdev->dev, "clk_in1");
 159         if (IS_ERR(clk_wzrd->clk_in1)) {
 160                 if (clk_wzrd->clk_in1 != ERR_PTR(-EPROBE_DEFER))
 161                         dev_err(&pdev->dev, "clk_in1 not found\n");
 162                 return PTR_ERR(clk_wzrd->clk_in1);
 163         }
 164
 165         clk_wzrd->axi_clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
 166         if (IS_ERR(clk_wzrd->axi_clk)) {
 167                 if (clk_wzrd->axi_clk != ERR_PTR(-EPROBE_DEFER))
 168                         dev_err(&pdev->dev, "s_axi_aclk not found\n");
 169                 return PTR_ERR(clk_wzrd->axi_clk);
 170         }
 171         ret = clk_prepare_enable(clk_wzrd->axi_clk);
 172         if (ret) {
 173                 dev_err(&pdev->dev, "enabling s_axi_aclk failed\n");
 174                 return ret;
 175         }
 176         rate = clk_get_rate(clk_wzrd->axi_clk);
 177         if (rate > WZRD_ACLK_MAX_FREQ) {
 178                 dev_err(&pdev->dev, "s_axi_aclk frequency (%lu) too high\n",
 179                         rate);
 180                 ret = -EINVAL;
 181                 goto err_disable_clk;
 182         }
 183
 184         /* we don't support fractional div/mul yet */
 185         reg = readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)) &
 186                     WZRD_CLKFBOUT_FRAC_EN;
 187         reg |= readl(clk_wzrd->base + WZRD_CLK_CFG_REG(2)) &
 188                      WZRD_CLKOUT0_FRAC_EN;
 189         if (reg)
 190                 dev_warn(&pdev->dev, "fractional div/mul not supported\n");
 191
 192         /* register multiplier */
 193         reg = (readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)) &
 194                      WZRD_CLKFBOUT_MULT_MASK) >> WZRD_CLKFBOUT_MULT_SHIFT;
 195         clk_name = kasprintf(GFP_KERNEL, "%s_mul", dev_name(&pdev->dev));
 196         if (!clk_name) {
 197                 ret = -ENOMEM;
 198                 goto err_disable_clk;
 199         }
 200         clk_wzrd->clks_internal[wzrd_clk_mul] = clk_register_fixed_factor
 201                         (&pdev->dev, clk_name,
 202                          __clk_get_name(clk_wzrd->clk_in1),
 203                          0, reg, 1);
 204         kfree(clk_name);
 205         if (IS_ERR(clk_wzrd->clks_internal[wzrd_clk_mul])) {
 206                 dev_err(&pdev->dev, "unable to register fixed-factor clock\n");
 207                 ret = PTR_ERR(clk_wzrd->clks_internal[wzrd_clk_mul]);
 208                 goto err_disable_clk;
 209         }
 210
 211         /* register div */
 212         reg = (readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)) &
 213                         WZRD_DIVCLK_DIVIDE_MASK) >> WZRD_DIVCLK_DIVIDE_SHIFT;
 214         clk_name = kasprintf(GFP_KERNEL, "%s_mul_div", dev_name(&pdev->dev));
 215         if (!clk_name) {
 216                 ret = -ENOMEM;
 217                 goto err_rm_int_clk;
 218         }
 219
 220         clk_wzrd->clks_internal[wzrd_clk_mul_div] = clk_register_fixed_factor
 221                         (&pdev->dev, clk_name,
 222                          __clk_get_name(clk_wzrd->clks_internal[wzrd_clk_mul]),
 223                          0, 1, reg);
 224         if (IS_ERR(clk_wzrd->clks_internal[wzrd_clk_mul_div])) {
 225                 dev_err(&pdev->dev, "unable to register divider clock\n");
 226                 ret = PTR_ERR(clk_wzrd->clks_internal[wzrd_clk_mul_div]);
 227                 goto err_rm_int_clk;
 228         }
 229
 230         /* register div per output */
 231         for (i = WZRD_NUM_OUTPUTS - 1; i >= 0 ; i--) {
 232                 const char *clkout_name;
 233
 234                 if (of_property_read_string_index(np, "clock-output-names", i,
 235                                                   &clkout_name)) {
 236                         dev_err(&pdev->dev,
 237                                 "clock output name not specified\n");
 238                         ret = -EINVAL;
 239                         goto err_rm_int_clks;
 240                 }
 241                 reg = readl(clk_wzrd->base + WZRD_CLK_CFG_REG(2) + i * 12);
 242                 reg &= WZRD_CLKOUT_DIVIDE_MASK;
 243                 reg >>= WZRD_CLKOUT_DIVIDE_SHIFT;
 244                 clk_wzrd->clkout[i] = clk_register_fixed_factor
 245                         (&pdev->dev, clkout_name, clk_name, 0, 1, reg);
 246                 if (IS_ERR(clk_wzrd->clkout[i])) {
 247                         int j;
 248
 249                         for (j = i + 1; j < WZRD_NUM_OUTPUTS; j++)
 250                                 clk_unregister(clk_wzrd->clkout[j]);
 251                         dev_err(&pdev->dev,
 252                                 "unable to register divider clock\n");
 253                         ret = PTR_ERR(clk_wzrd->clkout[i]);
 254                         goto err_rm_int_clks;
 255                 }
 256         }
 257
 258         kfree(clk_name);
 259
 260         clk_wzrd->clk_data.clks = clk_wzrd->clkout;
 261         clk_wzrd->clk_data.clk_num = ARRAY_SIZE(clk_wzrd->clkout);
 262         of_clk_add_provider(np, of_clk_src_onecell_get, &clk_wzrd->clk_data);
 263
 264         if (clk_wzrd->speed_grade) {
 265                 clk_wzrd->nb.notifier_call = clk_wzrd_clk_notifier;
 266
 267                 ret = clk_notifier_register(clk_wzrd->clk_in1,
 268                                             &clk_wzrd->nb);
 269                 if (ret)
 270                         dev_warn(&pdev->dev,
 271                                  "unable to register clock notifier\n");
 272
 273                 ret = clk_notifier_register(clk_wzrd->axi_clk, &clk_wzrd->nb);
 274                 if (ret)
 275                         dev_warn(&pdev->dev,
 276                                  "unable to register clock notifier\n");
 277         }
 278
 279         return 0;
 280
 281 err_rm_int_clks:
 282         clk_unregister(clk_wzrd->clks_internal[1]);
 283 err_rm_int_clk:
 284         kfree(clk_name);
 285         clk_unregister(clk_wzrd->clks_internal[0]);
 286 err_disable_clk:
 287         clk_disable_unprepare(clk_wzrd->axi_clk);
 288
 289         return ret;
 290 }
 291
 292 static int clk_wzrd_remove(struct platform_device *pdev)
 293 {
 294         int i;
 295         struct clk_wzrd *clk_wzrd = platform_get_drvdata(pdev);
 296
 297         of_clk_del_provider(pdev->dev.of_node);
 298
 299         for (i = 0; i < WZRD_NUM_OUTPUTS; i++)
 300                 clk_unregister(clk_wzrd->clkout[i]);
 301         for (i = 0; i < wzrd_clk_int_max; i++)
 302                 clk_unregister(clk_wzrd->clks_internal[i]);
 303
 304         if (clk_wzrd->speed_grade) {
 305                 clk_notifier_unregister(clk_wzrd->axi_clk, &clk_wzrd->nb);
 306                 clk_notifier_unregister(clk_wzrd->clk_in1, &clk_wzrd->nb);
 307         }
 308
 309         clk_disable_unprepare(clk_wzrd->axi_clk);
 310
 311         return 0;
 312 }
 313
 314 static const struct of_device_id clk_wzrd_ids[] = {
 315         { .compatible = "xlnx,clocking-wizard" },
 316         { },
 317 };
 318 MODULE_DEVICE_TABLE(of, clk_wzrd_ids);
 319
 320 static struct platform_driver clk_wzrd_driver = {
 321         .driver = {
 322                 .name = "clk-wizard",
 323                 .of_match_table = clk_wzrd_ids,
 324                 .pm = &clk_wzrd_dev_pm_ops,
 325         },
 326         .probe = clk_wzrd_probe,
 327         .remove = clk_wzrd_remove,
 328 };
 329 module_platform_driver(clk_wzrd_driver);
 330
 331 MODULE_LICENSE("GPL");
 332 MODULE_AUTHOR("Soeren Brinkmann <soren.brinkmann@xilinx.com");
 333 MODULE_DESCRIPTION("Driver for the Xilinx Clocking Wizard IP core");