kernel/drivers/clk/ti/clk-dra7-atl.c

   1 /*
   2  * DRA7 ATL (Audio Tracking Logic) clock driver
   3  *
   4  * Copyright (C) 2013 Texas Instruments, Inc.
   5  *
   6  * Peter Ujfalusi <peter.ujfalusi@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  13  * kind, whether express or implied; without even the implied warranty
  14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/clk-provider.h>
  20 #include <linux/slab.h>
  21 #include <linux/io.h>
  22 #include <linux/of.h>
  23 #include <linux/of_address.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/pm_runtime.h>
  26
  27 #define DRA7_ATL_INSTANCES      4
  28
  29 #define DRA7_ATL_PPMR_REG(id)           (0x200 + (id * 0x80))
  30 #define DRA7_ATL_BBSR_REG(id)           (0x204 + (id * 0x80))
  31 #define DRA7_ATL_ATLCR_REG(id)          (0x208 + (id * 0x80))
  32 #define DRA7_ATL_SWEN_REG(id)           (0x210 + (id * 0x80))
  33 #define DRA7_ATL_BWSMUX_REG(id)         (0x214 + (id * 0x80))
  34 #define DRA7_ATL_AWSMUX_REG(id)         (0x218 + (id * 0x80))
  35 #define DRA7_ATL_PCLKMUX_REG(id)        (0x21c + (id * 0x80))
  36
  37 #define DRA7_ATL_SWEN                   BIT(0)
  38 #define DRA7_ATL_DIVIDER_MASK           (0x1f)
  39 #define DRA7_ATL_PCLKMUX                BIT(0)
  40 struct dra7_atl_clock_info;
  41
  42 struct dra7_atl_desc {
  43         struct clk *clk;
  44         struct clk_hw hw;
  45         struct dra7_atl_clock_info *cinfo;
  46         int id;
  47
  48         bool probed;            /* the driver for the IP has been loaded */
  49         bool valid;             /* configured */
  50         bool enabled;
  51         u32 bws;                /* Baseband Word Select Mux */
  52         u32 aws;                /* Audio Word Select Mux */
  53         u32 divider;            /* Cached divider value */
  54 };
  55
  56 struct dra7_atl_clock_info {
  57         struct device *dev;
  58         void __iomem *iobase;
  59
  60         struct dra7_atl_desc *cdesc;
  61 };
  62
  63 #define to_atl_desc(_hw)        container_of(_hw, struct dra7_atl_desc, hw)
  64
  65 static inline void atl_write(struct dra7_atl_clock_info *cinfo, u32 reg,
  66                              u32 val)
  67 {
  68         __raw_writel(val, cinfo->iobase + reg);
  69 }
  70
  71 static inline int atl_read(struct dra7_atl_clock_info *cinfo, u32 reg)
  72 {
  73         return __raw_readl(cinfo->iobase + reg);
  74 }
  75
  76 static int atl_clk_enable(struct clk_hw *hw)
  77 {
  78         struct dra7_atl_desc *cdesc = to_atl_desc(hw);
  79
  80         if (!cdesc->probed)
  81                 goto out;
  82
  83         if (unlikely(!cdesc->valid))
  84                 dev_warn(cdesc->cinfo->dev, "atl%d has not been configured\n",
  85                          cdesc->id);
  86         pm_runtime_get_sync(cdesc->cinfo->dev);
  87
  88         atl_write(cdesc->cinfo, DRA7_ATL_ATLCR_REG(cdesc->id),
  89                   cdesc->divider - 1);
  90         atl_write(cdesc->cinfo, DRA7_ATL_SWEN_REG(cdesc->id), DRA7_ATL_SWEN);
  91
  92 out:
  93         cdesc->enabled = true;
  94
  95         return 0;
  96 }
  97
  98 static void atl_clk_disable(struct clk_hw *hw)
  99 {
 100         struct dra7_atl_desc *cdesc = to_atl_desc(hw);
 101
 102         if (!cdesc->probed)
 103                 goto out;
 104
 105         atl_write(cdesc->cinfo, DRA7_ATL_SWEN_REG(cdesc->id), 0);
 106         pm_runtime_put_sync(cdesc->cinfo->dev);
 107
 108 out:
 109         cdesc->enabled = false;
 110 }
 111
 112 static int atl_clk_is_enabled(struct clk_hw *hw)
 113 {
 114         struct dra7_atl_desc *cdesc = to_atl_desc(hw);
 115
 116         return cdesc->enabled;
 117 }
 118
 119 static unsigned long atl_clk_recalc_rate(struct clk_hw *hw,
 120                                          unsigned long parent_rate)
 121 {
 122         struct dra7_atl_desc *cdesc = to_atl_desc(hw);
 123
 124         return parent_rate / cdesc->divider;
 125 }
 126
 127 static long atl_clk_round_rate(struct clk_hw *hw, unsigned long rate,
 128                                unsigned long *parent_rate)
 129 {
 130         unsigned divider;
 131
 132         divider = (*parent_rate + rate / 2) / rate;
 133         if (divider > DRA7_ATL_DIVIDER_MASK + 1)
 134                 divider = DRA7_ATL_DIVIDER_MASK + 1;
 135
 136         return *parent_rate / divider;
 137 }
 138
 139 static int atl_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 140                             unsigned long parent_rate)
 141 {
 142         struct dra7_atl_desc *cdesc;
 143         u32 divider;
 144
 145         if (!hw || !rate)
 146                 return -EINVAL;
 147
 148         cdesc = to_atl_desc(hw);
 149         divider = ((parent_rate + rate / 2) / rate) - 1;
 150         if (divider > DRA7_ATL_DIVIDER_MASK)
 151                 divider = DRA7_ATL_DIVIDER_MASK;
 152
 153         cdesc->divider = divider + 1;
 154
 155         return 0;
 156 }
 157
 158 const struct clk_ops atl_clk_ops = {
 159         .enable         = atl_clk_enable,
 160         .disable        = atl_clk_disable,
 161         .is_enabled     = atl_clk_is_enabled,
 162         .recalc_rate    = atl_clk_recalc_rate,
 163         .round_rate     = atl_clk_round_rate,
 164         .set_rate       = atl_clk_set_rate,
 165 };
 166
 167 static void __init of_dra7_atl_clock_setup(struct device_node *node)
 168 {
 169         struct dra7_atl_desc *clk_hw = NULL;
 170         struct clk_init_data init = { 0 };
 171         const char **parent_names = NULL;
 172         struct clk *clk;
 173
 174         clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
 175         if (!clk_hw) {
 176                 pr_err("%s: could not allocate dra7_atl_desc\n", __func__);
 177                 return;
 178         }
 179
 180         clk_hw->hw.init = &init;
 181         clk_hw->divider = 1;
 182         init.name = node->name;
 183         init.ops = &atl_clk_ops;
 184         init.flags = CLK_IGNORE_UNUSED;
 185         init.num_parents = of_clk_get_parent_count(node);
 186
 187         if (init.num_parents != 1) {
 188                 pr_err("%s: atl clock %s must have 1 parent\n", __func__,
 189                        node->name);
 190                 goto cleanup;
 191         }
 192
 193         parent_names = kzalloc(sizeof(char *), GFP_KERNEL);
 194
 195         if (!parent_names)
 196                 goto cleanup;
 197
 198         parent_names[0] = of_clk_get_parent_name(node, 0);
 199
 200         init.parent_names = parent_names;
 201
 202         clk = clk_register(NULL, &clk_hw->hw);
 203
 204         if (!IS_ERR(clk)) {
 205                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 206                 kfree(parent_names);
 207                 return;
 208         }
 209 cleanup:
 210         kfree(parent_names);
 211         kfree(clk_hw);
 212 }
 213 CLK_OF_DECLARE(dra7_atl_clock, "ti,dra7-atl-clock", of_dra7_atl_clock_setup);
 214
 215 static int of_dra7_atl_clk_probe(struct platform_device *pdev)
 216 {
 217         struct device_node *node = pdev->dev.of_node;
 218         struct dra7_atl_clock_info *cinfo;
 219         int i;
 220         int ret = 0;
 221
 222         if (!node)
 223                 return -ENODEV;
 224
 225         cinfo = devm_kzalloc(&pdev->dev, sizeof(*cinfo), GFP_KERNEL);
 226         if (!cinfo)
 227                 return -ENOMEM;
 228
 229         cinfo->iobase = of_iomap(node, 0);
 230         cinfo->dev = &pdev->dev;
 231         pm_runtime_enable(cinfo->dev);
 232         pm_runtime_irq_safe(cinfo->dev);
 233
 234         pm_runtime_get_sync(cinfo->dev);
 235         atl_write(cinfo, DRA7_ATL_PCLKMUX_REG(0), DRA7_ATL_PCLKMUX);
 236
 237         for (i = 0; i < DRA7_ATL_INSTANCES; i++) {
 238                 struct device_node *cfg_node;
 239                 char prop[5];
 240                 struct dra7_atl_desc *cdesc;
 241                 struct of_phandle_args clkspec;
 242                 struct clk *clk;
 243                 int rc;
 244
 245                 rc = of_parse_phandle_with_args(node, "ti,provided-clocks",
 246                                                 NULL, i, &clkspec);
 247
 248                 if (rc) {
 249                         pr_err("%s: failed to lookup atl clock %d\n", __func__,
 250                                i);
 251                         return -EINVAL;
 252                 }
 253
 254                 clk = of_clk_get_from_provider(&clkspec);
 255
 256                 cdesc = to_atl_desc(__clk_get_hw(clk));
 257                 cdesc->cinfo = cinfo;
 258                 cdesc->id = i;
 259
 260                 /* Get configuration for the ATL instances */
 261                 snprintf(prop, sizeof(prop), "atl%u", i);
 262                 cfg_node = of_find_node_by_name(node, prop);
 263                 if (cfg_node) {
 264                         ret = of_property_read_u32(cfg_node, "bws",
 265                                                    &cdesc->bws);
 266                         ret |= of_property_read_u32(cfg_node, "aws",
 267                                                     &cdesc->aws);
 268                         if (!ret) {
 269                                 cdesc->valid = true;
 270                                 atl_write(cinfo, DRA7_ATL_BWSMUX_REG(i),
 271                                           cdesc->bws);
 272                                 atl_write(cinfo, DRA7_ATL_AWSMUX_REG(i),
 273                                           cdesc->aws);
 274                         }
 275                 }
 276
 277                 cdesc->probed = true;
 278                 /*
 279                  * Enable the clock if it has been asked prior to loading the
 280                  * hw driver
 281                  */
 282                 if (cdesc->enabled)
 283                         atl_clk_enable(__clk_get_hw(clk));
 284         }
 285         pm_runtime_put_sync(cinfo->dev);
 286
 287         return ret;
 288 }
 289
 290 static int of_dra7_atl_clk_remove(struct platform_device *pdev)
 291 {
 292         pm_runtime_disable(&pdev->dev);
 293
 294         return 0;
 295 }
 296
 297 static const struct of_device_id of_dra7_atl_clk_match_tbl[] = {
 298         { .compatible = "ti,dra7-atl", },
 299         {},
 300 };
 301 MODULE_DEVICE_TABLE(of, of_dra7_atl_clk_match_tbl);
 302
 303 static struct platform_driver dra7_atl_clk_driver = {
 304         .driver = {
 305                 .name = "dra7-atl",
 306                 .of_match_table = of_dra7_atl_clk_match_tbl,
 307         },
 308         .probe = of_dra7_atl_clk_probe,
 309         .remove = of_dra7_atl_clk_remove,
 310 };
 311
 312 module_platform_driver(dra7_atl_clk_driver);
 313
 314 MODULE_DESCRIPTION("Clock driver for DRA7 Audio Tracking Logic");
 315 MODULE_ALIAS("platform:dra7-atl-clock");
 316 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 317 MODULE_LICENSE("GPL v2");