linux/drivers/clk/clk-max77686.c
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   1/*
   2 * clk-max77686.c - Clock driver for Maxim 77686/MAX77802
   3 *
   4 * Copyright (C) 2012 Samsung Electornics
   5 * Jonghwa Lee <jonghwa3.lee@samsung.com>
   6 *
   7 * This program is free software; you can redistribute  it and/or modify it
   8 * under  the terms of  the GNU General  Public License as published by the
   9 * Free Software Foundation;  either version 2 of the  License, or (at your
  10 * option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 *
  21 */
  22
  23#include <linux/kernel.h>
  24#include <linux/slab.h>
  25#include <linux/err.h>
  26#include <linux/module.h>
  27#include <linux/platform_device.h>
  28#include <linux/mfd/max77620.h>
  29#include <linux/mfd/max77686.h>
  30#include <linux/mfd/max77686-private.h>
  31#include <linux/clk-provider.h>
  32#include <linux/mutex.h>
  33#include <linux/clkdev.h>
  34#include <linux/of.h>
  35#include <linux/regmap.h>
  36
  37#include <dt-bindings/clock/maxim,max77686.h>
  38#include <dt-bindings/clock/maxim,max77802.h>
  39#include <dt-bindings/clock/maxim,max77620.h>
  40
  41#define MAX77802_CLOCK_LOW_JITTER_SHIFT 0x3
  42
  43enum max77686_chip_name {
  44        CHIP_MAX77686,
  45        CHIP_MAX77802,
  46        CHIP_MAX77620,
  47};
  48
  49struct max77686_hw_clk_info {
  50        const char *name;
  51        u32 clk_reg;
  52        u32 clk_enable_mask;
  53        u32 flags;
  54};
  55
  56struct max77686_clk_init_data {
  57        struct regmap *regmap;
  58        struct clk_hw hw;
  59        struct clk_init_data clk_idata;
  60        const struct max77686_hw_clk_info *clk_info;
  61};
  62
  63struct max77686_clk_driver_data {
  64        enum max77686_chip_name chip;
  65        struct max77686_clk_init_data *max_clk_data;
  66        size_t num_clks;
  67};
  68
  69static const struct
  70max77686_hw_clk_info max77686_hw_clks_info[MAX77686_CLKS_NUM] = {
  71        [MAX77686_CLK_AP] = {
  72                .name = "32khz_ap",
  73                .clk_reg = MAX77686_REG_32KHZ,
  74                .clk_enable_mask = BIT(MAX77686_CLK_AP),
  75        },
  76        [MAX77686_CLK_CP] = {
  77                .name = "32khz_cp",
  78                .clk_reg = MAX77686_REG_32KHZ,
  79                .clk_enable_mask = BIT(MAX77686_CLK_CP),
  80        },
  81        [MAX77686_CLK_PMIC] = {
  82                .name = "32khz_pmic",
  83                .clk_reg = MAX77686_REG_32KHZ,
  84                .clk_enable_mask = BIT(MAX77686_CLK_PMIC),
  85        },
  86};
  87
  88static const struct
  89max77686_hw_clk_info max77802_hw_clks_info[MAX77802_CLKS_NUM] = {
  90        [MAX77802_CLK_32K_AP] = {
  91                .name = "32khz_ap",
  92                .clk_reg = MAX77802_REG_32KHZ,
  93                .clk_enable_mask = BIT(MAX77802_CLK_32K_AP),
  94        },
  95        [MAX77802_CLK_32K_CP] = {
  96                .name = "32khz_cp",
  97                .clk_reg = MAX77802_REG_32KHZ,
  98                .clk_enable_mask = BIT(MAX77802_CLK_32K_CP),
  99        },
 100};
 101
 102static const struct
 103max77686_hw_clk_info max77620_hw_clks_info[MAX77620_CLKS_NUM] = {
 104        [MAX77620_CLK_32K_OUT0] = {
 105                .name = "32khz_out0",
 106                .clk_reg = MAX77620_REG_CNFG1_32K,
 107                .clk_enable_mask = MAX77620_CNFG1_32K_OUT0_EN,
 108        },
 109};
 110
 111static struct max77686_clk_init_data *to_max77686_clk_init_data(
 112                                struct clk_hw *hw)
 113{
 114        return container_of(hw, struct max77686_clk_init_data, hw);
 115}
 116
 117static int max77686_clk_prepare(struct clk_hw *hw)
 118{
 119        struct max77686_clk_init_data *max77686 = to_max77686_clk_init_data(hw);
 120
 121        return regmap_update_bits(max77686->regmap, max77686->clk_info->clk_reg,
 122                                  max77686->clk_info->clk_enable_mask,
 123                                  max77686->clk_info->clk_enable_mask);
 124}
 125
 126static void max77686_clk_unprepare(struct clk_hw *hw)
 127{
 128        struct max77686_clk_init_data *max77686 = to_max77686_clk_init_data(hw);
 129
 130        regmap_update_bits(max77686->regmap, max77686->clk_info->clk_reg,
 131                           max77686->clk_info->clk_enable_mask,
 132                           ~max77686->clk_info->clk_enable_mask);
 133}
 134
 135static int max77686_clk_is_prepared(struct clk_hw *hw)
 136{
 137        struct max77686_clk_init_data *max77686 = to_max77686_clk_init_data(hw);
 138        int ret;
 139        u32 val;
 140
 141        ret = regmap_read(max77686->regmap, max77686->clk_info->clk_reg, &val);
 142
 143        if (ret < 0)
 144                return -EINVAL;
 145
 146        return val & max77686->clk_info->clk_enable_mask;
 147}
 148
 149static unsigned long max77686_recalc_rate(struct clk_hw *hw,
 150                                          unsigned long parent_rate)
 151{
 152        return 32768;
 153}
 154
 155static struct clk_ops max77686_clk_ops = {
 156        .prepare        = max77686_clk_prepare,
 157        .unprepare      = max77686_clk_unprepare,
 158        .is_prepared    = max77686_clk_is_prepared,
 159        .recalc_rate    = max77686_recalc_rate,
 160};
 161
 162static struct clk_hw *
 163of_clk_max77686_get(struct of_phandle_args *clkspec, void *data)
 164{
 165        struct max77686_clk_driver_data *drv_data = data;
 166        unsigned int idx = clkspec->args[0];
 167
 168        if (idx >= drv_data->num_clks) {
 169                pr_err("%s: invalid index %u\n", __func__, idx);
 170                return ERR_PTR(-EINVAL);
 171        }
 172
 173        return &drv_data->max_clk_data[idx].hw;
 174}
 175
 176static int max77686_clk_probe(struct platform_device *pdev)
 177{
 178        struct device *dev = &pdev->dev;
 179        struct device *parent = dev->parent;
 180        const struct platform_device_id *id = platform_get_device_id(pdev);
 181        struct max77686_clk_driver_data *drv_data;
 182        const struct max77686_hw_clk_info *hw_clks;
 183        struct regmap *regmap;
 184        int i, ret, num_clks;
 185
 186        drv_data = devm_kzalloc(dev, sizeof(*drv_data), GFP_KERNEL);
 187        if (!drv_data)
 188                return -ENOMEM;
 189
 190        regmap = dev_get_regmap(parent, NULL);
 191        if (!regmap) {
 192                dev_err(dev, "Failed to get rtc regmap\n");
 193                return -ENODEV;
 194        }
 195
 196        drv_data->chip = id->driver_data;
 197
 198        switch (drv_data->chip) {
 199        case CHIP_MAX77686:
 200                num_clks = MAX77686_CLKS_NUM;
 201                hw_clks = max77686_hw_clks_info;
 202                break;
 203
 204        case CHIP_MAX77802:
 205                num_clks = MAX77802_CLKS_NUM;
 206                hw_clks = max77802_hw_clks_info;
 207                break;
 208
 209        case CHIP_MAX77620:
 210                num_clks = MAX77620_CLKS_NUM;
 211                hw_clks = max77620_hw_clks_info;
 212                break;
 213
 214        default:
 215                dev_err(dev, "Unknown Chip ID\n");
 216                return -EINVAL;
 217        }
 218
 219        drv_data->num_clks = num_clks;
 220        drv_data->max_clk_data = devm_kcalloc(dev, num_clks,
 221                                              sizeof(*drv_data->max_clk_data),
 222                                              GFP_KERNEL);
 223        if (!drv_data->max_clk_data)
 224                return -ENOMEM;
 225
 226        for (i = 0; i < num_clks; i++) {
 227                struct max77686_clk_init_data *max_clk_data;
 228                const char *clk_name;
 229
 230                max_clk_data = &drv_data->max_clk_data[i];
 231
 232                max_clk_data->regmap = regmap;
 233                max_clk_data->clk_info = &hw_clks[i];
 234                max_clk_data->clk_idata.flags = hw_clks[i].flags;
 235                max_clk_data->clk_idata.ops = &max77686_clk_ops;
 236
 237                if (parent->of_node &&
 238                    !of_property_read_string_index(parent->of_node,
 239                                                   "clock-output-names",
 240                                                   i, &clk_name))
 241                        max_clk_data->clk_idata.name = clk_name;
 242                else
 243                        max_clk_data->clk_idata.name = hw_clks[i].name;
 244
 245                max_clk_data->hw.init = &max_clk_data->clk_idata;
 246
 247                ret = devm_clk_hw_register(dev, &max_clk_data->hw);
 248                if (ret) {
 249                        dev_err(dev, "Failed to clock register: %d\n", ret);
 250                        return ret;
 251                }
 252
 253                ret = clk_hw_register_clkdev(&max_clk_data->hw,
 254                                             max_clk_data->clk_idata.name, NULL);
 255                if (ret < 0) {
 256                        dev_err(dev, "Failed to clkdev register: %d\n", ret);
 257                        return ret;
 258                }
 259        }
 260
 261        if (parent->of_node) {
 262                ret = of_clk_add_hw_provider(parent->of_node, of_clk_max77686_get,
 263                                             drv_data);
 264
 265                if (ret < 0) {
 266                        dev_err(dev, "Failed to register OF clock provider: %d\n",
 267                                ret);
 268                        return ret;
 269                }
 270        }
 271
 272        /* MAX77802: Enable low-jitter mode on the 32khz clocks. */
 273        if (drv_data->chip == CHIP_MAX77802) {
 274                ret = regmap_update_bits(regmap, MAX77802_REG_32KHZ,
 275                                         1 << MAX77802_CLOCK_LOW_JITTER_SHIFT,
 276                                         1 << MAX77802_CLOCK_LOW_JITTER_SHIFT);
 277                if (ret < 0) {
 278                        dev_err(dev, "Failed to config low-jitter: %d\n", ret);
 279                        goto remove_of_clk_provider;
 280                }
 281        }
 282
 283        return 0;
 284
 285remove_of_clk_provider:
 286        if (parent->of_node)
 287                of_clk_del_provider(parent->of_node);
 288
 289        return ret;
 290}
 291
 292static int max77686_clk_remove(struct platform_device *pdev)
 293{
 294        struct device *parent = pdev->dev.parent;
 295
 296        if (parent->of_node)
 297                of_clk_del_provider(parent->of_node);
 298
 299        return 0;
 300}
 301
 302static const struct platform_device_id max77686_clk_id[] = {
 303        { "max77686-clk", .driver_data = CHIP_MAX77686, },
 304        { "max77802-clk", .driver_data = CHIP_MAX77802, },
 305        { "max77620-clock", .driver_data = CHIP_MAX77620, },
 306        {},
 307};
 308MODULE_DEVICE_TABLE(platform, max77686_clk_id);
 309
 310static struct platform_driver max77686_clk_driver = {
 311        .driver = {
 312                .name  = "max77686-clk",
 313        },
 314        .probe = max77686_clk_probe,
 315        .remove = max77686_clk_remove,
 316        .id_table = max77686_clk_id,
 317};
 318
 319module_platform_driver(max77686_clk_driver);
 320
 321MODULE_DESCRIPTION("MAXIM 77686 Clock Driver");
 322MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>");
 323MODULE_LICENSE("GPL");
 324