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