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 = to_atl_desc(hw);
 143         u32 divider;
 144
 145         divider = ((parent_rate + rate / 2) / rate) - 1;
 146         if (divider > DRA7_ATL_DIVIDER_MASK)
 147                 divider = DRA7_ATL_DIVIDER_MASK;
 148
 149         cdesc->divider = divider + 1;
 150
 151         return 0;
 152 }
 153
 154 const struct clk_ops atl_clk_ops = {
 155         .enable         = atl_clk_enable,
 156         .disable        = atl_clk_disable,
 157         .is_enabled     = atl_clk_is_enabled,
 158         .recalc_rate    = atl_clk_recalc_rate,
 159         .round_rate     = atl_clk_round_rate,
 160         .set_rate       = atl_clk_set_rate,
 161 };
 162
 163 static void __init of_dra7_atl_clock_setup(struct device_node *node)
 164 {
 165         struct dra7_atl_desc *clk_hw = NULL;
 166         struct clk_init_data init = { 0 };
 167         const char **parent_names = NULL;
 168         struct clk *clk;
 169
 170         clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
 171         if (!clk_hw) {
 172                 pr_err("%s: could not allocate dra7_atl_desc\n", __func__);
 173                 return;
 174         }
 175
 176         clk_hw->hw.init = &init;
 177         clk_hw->divider = 1;
 178         init.name = node->name;
 179         init.ops = &atl_clk_ops;
 180         init.flags = CLK_IGNORE_UNUSED;
 181         init.num_parents = of_clk_get_parent_count(node);
 182
 183         if (init.num_parents != 1) {
 184                 pr_err("%s: atl clock %s must have 1 parent\n", __func__,
 185                        node->name);
 186                 goto cleanup;
 187         }
 188
 189         parent_names = kzalloc(sizeof(char *), GFP_KERNEL);
 190
 191         if (!parent_names)
 192                 goto cleanup;
 193
 194         parent_names[0] = of_clk_get_parent_name(node, 0);
 195
 196         init.parent_names = parent_names;
 197
 198         clk = clk_register(NULL, &clk_hw->hw);
 199
 200         if (!IS_ERR(clk)) {
 201                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 202                 return;
 203         }
 204 cleanup:
 205         kfree(parent_names);
 206         kfree(clk_hw);
 207 }
 208 CLK_OF_DECLARE(dra7_atl_clock, "ti,dra7-atl-clock", of_dra7_atl_clock_setup);
 209
 210 static int of_dra7_atl_clk_probe(struct platform_device *pdev)
 211 {
 212         struct device_node *node = pdev->dev.of_node;
 213         struct dra7_atl_clock_info *cinfo;
 214         int i;
 215         int ret = 0;
 216
 217         if (!node)
 218                 return -ENODEV;
 219
 220         cinfo = devm_kzalloc(&pdev->dev, sizeof(*cinfo), GFP_KERNEL);
 221         if (!cinfo)
 222                 return -ENOMEM;
 223
 224         cinfo->iobase = of_iomap(node, 0);
 225         cinfo->dev = &pdev->dev;
 226         pm_runtime_enable(cinfo->dev);
 227
 228         pm_runtime_get_sync(cinfo->dev);
 229         atl_write(cinfo, DRA7_ATL_PCLKMUX_REG(0), DRA7_ATL_PCLKMUX);
 230
 231         for (i = 0; i < DRA7_ATL_INSTANCES; i++) {
 232                 struct device_node *cfg_node;
 233                 char prop[5];
 234                 struct dra7_atl_desc *cdesc;
 235                 struct of_phandle_args clkspec;
 236                 struct clk *clk;
 237                 int rc;
 238
 239                 rc = of_parse_phandle_with_args(node, "ti,provided-clocks",
 240                                                 NULL, i, &clkspec);
 241
 242                 if (rc) {
 243                         pr_err("%s: failed to lookup atl clock %d\n", __func__,
 244                                i);
 245                         return -EINVAL;
 246                 }
 247
 248                 clk = of_clk_get_from_provider(&clkspec);
 249
 250                 cdesc = to_atl_desc(__clk_get_hw(clk));
 251                 cdesc->cinfo = cinfo;
 252                 cdesc->id = i;
 253
 254                 /* Get configuration for the ATL instances */
 255                 snprintf(prop, sizeof(prop), "atl%u", i);
 256                 cfg_node = of_find_node_by_name(node, prop);
 257                 if (cfg_node) {
 258                         ret = of_property_read_u32(cfg_node, "bws",
 259                                                    &cdesc->bws);
 260                         ret |= of_property_read_u32(cfg_node, "aws",
 261                                                     &cdesc->aws);
 262                         if (!ret) {
 263                                 cdesc->valid = true;
 264                                 atl_write(cinfo, DRA7_ATL_BWSMUX_REG(i),
 265                                           cdesc->bws);
 266                                 atl_write(cinfo, DRA7_ATL_AWSMUX_REG(i),
 267                                           cdesc->aws);
 268                         }
 269                 }
 270
 271                 cdesc->probed = true;
 272                 /*
 273                  * Enable the clock if it has been asked prior to loading the
 274                  * hw driver
 275                  */
 276                 if (cdesc->enabled)
 277                         atl_clk_enable(__clk_get_hw(clk));
 278         }
 279         pm_runtime_put_sync(cinfo->dev);
 280
 281         return ret;
 282 }
 283
 284 static int of_dra7_atl_clk_remove(struct platform_device *pdev)
 285 {
 286         pm_runtime_disable(&pdev->dev);
 287
 288         return 0;
 289 }
 290
 291 static struct of_device_id of_dra7_atl_clk_match_tbl[] = {
 292         { .compatible = "ti,dra7-atl", },
 293         {},
 294 };
 295 MODULE_DEVICE_TABLE(of, of_dra7_atl_clk_match_tbl);
 296
 297 static struct platform_driver dra7_atl_clk_driver = {
 298         .driver = {
 299                 .name = "dra7-atl",
 300                 .owner = THIS_MODULE,
 301                 .of_match_table = of_dra7_atl_clk_match_tbl,
 302         },
 303         .probe = of_dra7_atl_clk_probe,
 304         .remove = of_dra7_atl_clk_remove,
 305 };
 306
 307 module_platform_driver(dra7_atl_clk_driver);
 308
 309 MODULE_DESCRIPTION("Clock driver for DRA7 Audio Tracking Logic");
 310 MODULE_ALIAS("platform:dra7-atl-clock");
 311 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 312 MODULE_LICENSE("GPL v2");