drivers/clk/clk-palmas.c

   1 /*
   2  * Clock driver for Palmas device.
   3  *
   4  * Copyright (c) 2013, NVIDIA Corporation.
   5  * Copyright (c) 2013-2014 Texas Instruments, Inc.
   6  *
   7  * Author:      Laxman Dewangan <ldewangan@nvidia.com>
   8  *              Peter Ujfalusi <peter.ujfalusi@ti.com>
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation version 2.
  13  *
  14  * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
  15  * whether express or implied; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17  * General Public License for more details.
  18  */
  19
  20 #include <linux/clk.h>
  21 #include <linux/clk-provider.h>
  22 #include <linux/mfd/palmas.h>
  23 #include <linux/module.h>
  24 #include <linux/of.h>
  25 #include <linux/of_device.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/slab.h>
  28
  29 #define PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE1     1
  30 #define PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE2     2
  31 #define PALMAS_CLOCK_DT_EXT_CONTROL_NSLEEP      3
  32
  33 struct palmas_clk32k_desc {
  34         const char *clk_name;
  35         unsigned int control_reg;
  36         unsigned int enable_mask;
  37         unsigned int sleep_mask;
  38         unsigned int sleep_reqstr_id;
  39         int delay;
  40 };
  41
  42 struct palmas_clock_info {
  43         struct device *dev;
  44         struct clk *clk;
  45         struct clk_hw hw;
  46         struct palmas *palmas;
  47         struct palmas_clk32k_desc *clk_desc;
  48         int ext_control_pin;
  49 };
  50
  51 static inline struct palmas_clock_info *to_palmas_clks_info(struct clk_hw *hw)
  52 {
  53         return container_of(hw, struct palmas_clock_info, hw);
  54 }
  55
  56 static unsigned long palmas_clks_recalc_rate(struct clk_hw *hw,
  57                                              unsigned long parent_rate)
  58 {
  59         return 32768;
  60 }
  61
  62 static int palmas_clks_prepare(struct clk_hw *hw)
  63 {
  64         struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
  65         int ret;
  66
  67         ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
  68                                  cinfo->clk_desc->control_reg,
  69                                  cinfo->clk_desc->enable_mask,
  70                                  cinfo->clk_desc->enable_mask);
  71         if (ret < 0)
  72                 dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
  73                         cinfo->clk_desc->control_reg, ret);
  74         else if (cinfo->clk_desc->delay)
  75                 udelay(cinfo->clk_desc->delay);
  76
  77         return ret;
  78 }
  79
  80 static void palmas_clks_unprepare(struct clk_hw *hw)
  81 {
  82         struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
  83         int ret;
  84
  85         /*
  86          * Clock can be disabled through external pin if it is externally
  87          * controlled.
  88          */
  89         if (cinfo->ext_control_pin)
  90                 return;
  91
  92         ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
  93                                  cinfo->clk_desc->control_reg,
  94                                  cinfo->clk_desc->enable_mask, 0);
  95         if (ret < 0)
  96                 dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
  97                         cinfo->clk_desc->control_reg, ret);
  98 }
  99
 100 static int palmas_clks_is_prepared(struct clk_hw *hw)
 101 {
 102         struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
 103         int ret;
 104         u32 val;
 105
 106         if (cinfo->ext_control_pin)
 107                 return 1;
 108
 109         ret = palmas_read(cinfo->palmas, PALMAS_RESOURCE_BASE,
 110                           cinfo->clk_desc->control_reg, &val);
 111         if (ret < 0) {
 112                 dev_err(cinfo->dev, "Reg 0x%02x read failed, %d\n",
 113                         cinfo->clk_desc->control_reg, ret);
 114                 return ret;
 115         }
 116         return !!(val & cinfo->clk_desc->enable_mask);
 117 }
 118
 119 static struct clk_ops palmas_clks_ops = {
 120         .prepare        = palmas_clks_prepare,
 121         .unprepare      = palmas_clks_unprepare,
 122         .is_prepared    = palmas_clks_is_prepared,
 123         .recalc_rate    = palmas_clks_recalc_rate,
 124 };
 125
 126 struct palmas_clks_of_match_data {
 127         struct clk_init_data init;
 128         struct palmas_clk32k_desc desc;
 129 };
 130
 131 static struct palmas_clks_of_match_data palmas_of_clk32kg = {
 132         .init = {
 133                 .name = "clk32kg",
 134                 .ops = &palmas_clks_ops,
 135                 .flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED,
 136         },
 137         .desc = {
 138                 .clk_name = "clk32kg",
 139                 .control_reg = PALMAS_CLK32KG_CTRL,
 140                 .enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
 141                 .sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
 142                 .sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KG,
 143                 .delay = 200,
 144         },
 145 };
 146
 147 static struct palmas_clks_of_match_data palmas_of_clk32kgaudio = {
 148         .init = {
 149                 .name = "clk32kgaudio",
 150                 .ops = &palmas_clks_ops,
 151                 .flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED,
 152         },
 153         .desc = {
 154                 .clk_name = "clk32kgaudio",
 155                 .control_reg = PALMAS_CLK32KGAUDIO_CTRL,
 156                 .enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
 157                 .sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
 158                 .sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KGAUDIO,
 159                 .delay = 200,
 160         },
 161 };
 162
 163 static const struct of_device_id palmas_clks_of_match[] = {
 164         {
 165                 .compatible = "ti,palmas-clk32kg",
 166                 .data = &palmas_of_clk32kg,
 167         },
 168         {
 169                 .compatible = "ti,palmas-clk32kgaudio",
 170                 .data = &palmas_of_clk32kgaudio,
 171         },
 172         { },
 173 };
 174 MODULE_DEVICE_TABLE(of, palmas_clks_of_match);
 175
 176 static void palmas_clks_get_clk_data(struct platform_device *pdev,
 177                                      struct palmas_clock_info *cinfo)
 178 {
 179         struct device_node *node = pdev->dev.of_node;
 180         unsigned int prop;
 181         int ret;
 182
 183         ret = of_property_read_u32(node, "ti,external-sleep-control",
 184                                    &prop);
 185         if (ret)
 186                 return;
 187
 188         switch (prop) {
 189         case PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE1:
 190                 prop = PALMAS_EXT_CONTROL_ENABLE1;
 191                 break;
 192         case PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE2:
 193                 prop = PALMAS_EXT_CONTROL_ENABLE2;
 194                 break;
 195         case PALMAS_CLOCK_DT_EXT_CONTROL_NSLEEP:
 196                 prop = PALMAS_EXT_CONTROL_NSLEEP;
 197                 break;
 198         default:
 199                 dev_warn(&pdev->dev, "%s: Invalid ext control option: %u\n",
 200                          node->name, prop);
 201                 prop = 0;
 202                 break;
 203         }
 204         cinfo->ext_control_pin = prop;
 205 }
 206
 207 static int palmas_clks_init_configure(struct palmas_clock_info *cinfo)
 208 {
 209         int ret;
 210
 211         ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
 212                                  cinfo->clk_desc->control_reg,
 213                                  cinfo->clk_desc->sleep_mask, 0);
 214         if (ret < 0) {
 215                 dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
 216                         cinfo->clk_desc->control_reg, ret);
 217                 return ret;
 218         }
 219
 220         if (cinfo->ext_control_pin) {
 221                 ret = clk_prepare(cinfo->clk);
 222                 if (ret < 0) {
 223                         dev_err(cinfo->dev, "Clock prep failed, %d\n", ret);
 224                         return ret;
 225                 }
 226
 227                 ret = palmas_ext_control_req_config(cinfo->palmas,
 228                                         cinfo->clk_desc->sleep_reqstr_id,
 229                                         cinfo->ext_control_pin, true);
 230                 if (ret < 0) {
 231                         dev_err(cinfo->dev, "Ext config for %s failed, %d\n",
 232                                 cinfo->clk_desc->clk_name, ret);
 233                         return ret;
 234                 }
 235         }
 236
 237         return ret;
 238 }
 239 static int palmas_clks_probe(struct platform_device *pdev)
 240 {
 241         struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
 242         struct device_node *node = pdev->dev.of_node;
 243         struct palmas_clks_of_match_data *match_data;
 244         const struct of_device_id *match;
 245         struct palmas_clock_info *cinfo;
 246         struct clk *clk;
 247         int ret;
 248
 249         match = of_match_device(palmas_clks_of_match, &pdev->dev);
 250         match_data = (struct palmas_clks_of_match_data *)match->data;
 251
 252         cinfo = devm_kzalloc(&pdev->dev, sizeof(*cinfo), GFP_KERNEL);
 253         if (!cinfo)
 254                 return -ENOMEM;
 255
 256         palmas_clks_get_clk_data(pdev, cinfo);
 257         platform_set_drvdata(pdev, cinfo);
 258
 259         cinfo->dev = &pdev->dev;
 260         cinfo->palmas = palmas;
 261
 262         cinfo->clk_desc = &match_data->desc;
 263         cinfo->hw.init = &match_data->init;
 264         clk = devm_clk_register(&pdev->dev, &cinfo->hw);
 265         if (IS_ERR(clk)) {
 266                 ret = PTR_ERR(clk);
 267                 dev_err(&pdev->dev, "Fail to register clock %s, %d\n",
 268                         match_data->desc.clk_name, ret);
 269                 return ret;
 270         }
 271
 272         cinfo->clk = clk;
 273         ret = palmas_clks_init_configure(cinfo);
 274         if (ret < 0) {
 275                 dev_err(&pdev->dev, "Clock config failed, %d\n", ret);
 276                 return ret;
 277         }
 278
 279         ret = of_clk_add_provider(node, of_clk_src_simple_get, cinfo->clk);
 280         if (ret < 0)
 281                 dev_err(&pdev->dev, "Fail to add clock driver, %d\n", ret);
 282         return ret;
 283 }
 284
 285 static int palmas_clks_remove(struct platform_device *pdev)
 286 {
 287         of_clk_del_provider(pdev->dev.of_node);
 288         return 0;
 289 }
 290
 291 static struct platform_driver palmas_clks_driver = {
 292         .driver = {
 293                 .name = "palmas-clk",
 294                 .of_match_table = palmas_clks_of_match,
 295         },
 296         .probe = palmas_clks_probe,
 297         .remove = palmas_clks_remove,
 298 };
 299
 300 module_platform_driver(palmas_clks_driver);
 301
 302 MODULE_DESCRIPTION("Clock driver for Palmas Series Devices");
 303 MODULE_ALIAS("platform:palmas-clk");
 304 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 305 MODULE_LICENSE("GPL v2");