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.h>
  20 #include <linux/clk-provider.h>
  21 #include <linux/slab.h>
  22 #include <linux/io.h>
  23 #include <linux/of.h>
  24 #include <linux/of_address.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/pm_runtime.h>
  27
  28 #define DRA7_ATL_INSTANCES      4
  29
  30 #define DRA7_ATL_PPMR_REG(id)           (0x200 + (id * 0x80))
  31 #define DRA7_ATL_BBSR_REG(id)           (0x204 + (id * 0x80))
  32 #define DRA7_ATL_ATLCR_REG(id)          (0x208 + (id * 0x80))
  33 #define DRA7_ATL_SWEN_REG(id)           (0x210 + (id * 0x80))
  34 #define DRA7_ATL_BWSMUX_REG(id)         (0x214 + (id * 0x80))
  35 #define DRA7_ATL_AWSMUX_REG(id)         (0x218 + (id * 0x80))
  36 #define DRA7_ATL_PCLKMUX_REG(id)        (0x21c + (id * 0x80))
  37
  38 #define DRA7_ATL_SWEN                   BIT(0)
  39 #define DRA7_ATL_DIVIDER_MASK           (0x1f)
  40 #define DRA7_ATL_PCLKMUX                BIT(0)
  41 struct dra7_atl_clock_info;
  42
  43 struct dra7_atl_desc {
  44         struct clk *clk;
  45         struct clk_hw hw;
  46         struct dra7_atl_clock_info *cinfo;
  47         int id;
  48
  49         bool probed;            /* the driver for the IP has been loaded */
  50         bool valid;             /* configured */
  51         bool enabled;
  52         u32 bws;                /* Baseband Word Select Mux */
  53         u32 aws;                /* Audio Word Select Mux */
  54         u32 divider;            /* Cached divider value */
  55 };
  56
  57 struct dra7_atl_clock_info {
  58         struct device *dev;
  59         void __iomem *iobase;
  60
  61         struct dra7_atl_desc *cdesc;
  62 };
  63
  64 #define to_atl_desc(_hw)        container_of(_hw, struct dra7_atl_desc, hw)
  65
  66 static inline void atl_write(struct dra7_atl_clock_info *cinfo, u32 reg,
  67                              u32 val)
  68 {
  69         __raw_writel(val, cinfo->iobase + reg);
  70 }
  71
  72 static inline int atl_read(struct dra7_atl_clock_info *cinfo, u32 reg)
  73 {
  74         return __raw_readl(cinfo->iobase + reg);
  75 }
  76
  77 static int atl_clk_enable(struct clk_hw *hw)
  78 {
  79         struct dra7_atl_desc *cdesc = to_atl_desc(hw);
  80
  81         if (!cdesc->probed)
  82                 goto out;
  83
  84         if (unlikely(!cdesc->valid))
  85                 dev_warn(cdesc->cinfo->dev, "atl%d has not been configured\n",
  86                          cdesc->id);
  87         pm_runtime_get_sync(cdesc->cinfo->dev);
  88
  89         atl_write(cdesc->cinfo, DRA7_ATL_ATLCR_REG(cdesc->id),
  90                   cdesc->divider - 1);
  91         atl_write(cdesc->cinfo, DRA7_ATL_SWEN_REG(cdesc->id), DRA7_ATL_SWEN);
  92
  93 out:
  94         cdesc->enabled = true;
  95
  96         return 0;
  97 }
  98
  99 static void atl_clk_disable(struct clk_hw *hw)
 100 {
 101         struct dra7_atl_desc *cdesc = to_atl_desc(hw);
 102
 103         if (!cdesc->probed)
 104                 goto out;
 105
 106         atl_write(cdesc->cinfo, DRA7_ATL_SWEN_REG(cdesc->id), 0);
 107         pm_runtime_put_sync(cdesc->cinfo->dev);
 108
 109 out:
 110         cdesc->enabled = false;
 111 }
 112
 113 static int atl_clk_is_enabled(struct clk_hw *hw)
 114 {
 115         struct dra7_atl_desc *cdesc = to_atl_desc(hw);
 116
 117         return cdesc->enabled;
 118 }
 119
 120 static unsigned long atl_clk_recalc_rate(struct clk_hw *hw,
 121                                          unsigned long parent_rate)
 122 {
 123         struct dra7_atl_desc *cdesc = to_atl_desc(hw);
 124
 125         return parent_rate / cdesc->divider;
 126 }
 127
 128 static long atl_clk_round_rate(struct clk_hw *hw, unsigned long rate,
 129                                unsigned long *parent_rate)
 130 {
 131         unsigned divider;
 132
 133         divider = (*parent_rate + rate / 2) / rate;
 134         if (divider > DRA7_ATL_DIVIDER_MASK + 1)
 135                 divider = DRA7_ATL_DIVIDER_MASK + 1;
 136
 137         return *parent_rate / divider;
 138 }
 139
 140 static int atl_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 141                             unsigned long parent_rate)
 142 {
 143         struct dra7_atl_desc *cdesc;
 144         u32 divider;
 145
 146         if (!hw || !rate)
 147                 return -EINVAL;
 148
 149         cdesc = to_atl_desc(hw);
 150         divider = ((parent_rate + rate / 2) / rate) - 1;
 151         if (divider > DRA7_ATL_DIVIDER_MASK)
 152                 divider = DRA7_ATL_DIVIDER_MASK;
 153
 154         cdesc->divider = divider + 1;
 155
 156         return 0;
 157 }
 158
 159 static const struct clk_ops atl_clk_ops = {
 160         .enable         = atl_clk_enable,
 161         .disable        = atl_clk_disable,
 162         .is_enabled     = atl_clk_is_enabled,
 163         .recalc_rate    = atl_clk_recalc_rate,
 164         .round_rate     = atl_clk_round_rate,
 165         .set_rate       = atl_clk_set_rate,
 166 };
 167
 168 static void __init of_dra7_atl_clock_setup(struct device_node *node)
 169 {
 170         struct dra7_atl_desc *clk_hw = NULL;
 171         struct clk_init_data init = { NULL };
 172         const char **parent_names = NULL;
 173         struct clk *clk;
 174
 175         clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
 176         if (!clk_hw) {
 177                 pr_err("%s: could not allocate dra7_atl_desc\n", __func__);
 178                 return;
 179         }
 180
 181         clk_hw->hw.init = &init;
 182         clk_hw->divider = 1;
 183         init.name = node->name;
 184         init.ops = &atl_clk_ops;
 185         init.flags = CLK_IGNORE_UNUSED;
 186         init.num_parents = of_clk_get_parent_count(node);
 187
 188         if (init.num_parents != 1) {
 189                 pr_err("%s: atl clock %s must have 1 parent\n", __func__,
 190                        node->name);
 191                 goto cleanup;
 192         }
 193
 194         parent_names = kzalloc(sizeof(char *), GFP_KERNEL);
 195
 196         if (!parent_names)
 197                 goto cleanup;
 198
 199         parent_names[0] = of_clk_get_parent_name(node, 0);
 200
 201         init.parent_names = parent_names;
 202
 203         clk = clk_register(NULL, &clk_hw->hw);
 204
 205         if (!IS_ERR(clk)) {
 206                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 207                 kfree(parent_names);
 208                 return;
 209         }
 210 cleanup:
 211         kfree(parent_names);
 212         kfree(clk_hw);
 213 }
 214 CLK_OF_DECLARE(dra7_atl_clock, "ti,dra7-atl-clock", of_dra7_atl_clock_setup);
 215
 216 static int of_dra7_atl_clk_probe(struct platform_device *pdev)
 217 {
 218         struct device_node *node = pdev->dev.of_node;
 219         struct dra7_atl_clock_info *cinfo;
 220         int i;
 221         int ret = 0;
 222
 223         if (!node)
 224                 return -ENODEV;
 225
 226         cinfo = devm_kzalloc(&pdev->dev, sizeof(*cinfo), GFP_KERNEL);
 227         if (!cinfo)
 228                 return -ENOMEM;
 229
 230         cinfo->iobase = of_iomap(node, 0);
 231         cinfo->dev = &pdev->dev;
 232         pm_runtime_enable(cinfo->dev);
 233         pm_runtime_irq_safe(cinfo->dev);
 234
 235         pm_runtime_get_sync(cinfo->dev);
 236         atl_write(cinfo, DRA7_ATL_PCLKMUX_REG(0), DRA7_ATL_PCLKMUX);
 237
 238         for (i = 0; i < DRA7_ATL_INSTANCES; i++) {
 239                 struct device_node *cfg_node;
 240                 char prop[5];
 241                 struct dra7_atl_desc *cdesc;
 242                 struct of_phandle_args clkspec;
 243                 struct clk *clk;
 244                 int rc;
 245
 246                 rc = of_parse_phandle_with_args(node, "ti,provided-clocks",
 247                                                 NULL, i, &clkspec);
 248
 249                 if (rc) {
 250                         pr_err("%s: failed to lookup atl clock %d\n", __func__,
 251                                i);
 252                         return -EINVAL;
 253                 }
 254
 255                 clk = of_clk_get_from_provider(&clkspec);
 256                 if (IS_ERR(clk)) {
 257                         pr_err("%s: failed to get atl clock %d from provider\n",
 258                                __func__, i);
 259                         return PTR_ERR(clk);
 260                 }
 261
 262                 cdesc = to_atl_desc(__clk_get_hw(clk));
 263                 cdesc->cinfo = cinfo;
 264                 cdesc->id = i;
 265
 266                 /* Get configuration for the ATL instances */
 267                 snprintf(prop, sizeof(prop), "atl%u", i);
 268                 cfg_node = of_find_node_by_name(node, prop);
 269                 if (cfg_node) {
 270                         ret = of_property_read_u32(cfg_node, "bws",
 271                                                    &cdesc->bws);
 272                         ret |= of_property_read_u32(cfg_node, "aws",
 273                                                     &cdesc->aws);
 274                         if (!ret) {
 275                                 cdesc->valid = true;
 276                                 atl_write(cinfo, DRA7_ATL_BWSMUX_REG(i),
 277                                           cdesc->bws);
 278                                 atl_write(cinfo, DRA7_ATL_AWSMUX_REG(i),
 279                                           cdesc->aws);
 280                         }
 281                 }
 282
 283                 cdesc->probed = true;
 284                 /*
 285                  * Enable the clock if it has been asked prior to loading the
 286                  * hw driver
 287                  */
 288                 if (cdesc->enabled)
 289                         atl_clk_enable(__clk_get_hw(clk));
 290         }
 291         pm_runtime_put_sync(cinfo->dev);
 292
 293         return ret;
 294 }
 295
 296 static int of_dra7_atl_clk_remove(struct platform_device *pdev)
 297 {
 298         pm_runtime_disable(&pdev->dev);
 299
 300         return 0;
 301 }
 302
 303 static const struct of_device_id of_dra7_atl_clk_match_tbl[] = {
 304         { .compatible = "ti,dra7-atl", },
 305         {},
 306 };
 307 MODULE_DEVICE_TABLE(of, of_dra7_atl_clk_match_tbl);
 308
 309 static struct platform_driver dra7_atl_clk_driver = {
 310         .driver = {
 311                 .name = "dra7-atl",
 312                 .of_match_table = of_dra7_atl_clk_match_tbl,
 313         },
 314         .probe = of_dra7_atl_clk_probe,
 315         .remove = of_dra7_atl_clk_remove,
 316 };
 317
 318 module_platform_driver(dra7_atl_clk_driver);
 319
 320 MODULE_DESCRIPTION("Clock driver for DRA7 Audio Tracking Logic");
 321 MODULE_ALIAS("platform:dra7-atl-clock");
 322 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 323 MODULE_LICENSE("GPL v2");