arch/arm/mach-davinci/cdce949.c

   1 /*
   2  * TI CDCE949 clock synthesizer driver
   3  *
   4  * Note: This implementation assumes an input of 27MHz to the CDCE.
   5  * This is by no means constrained by CDCE hardware although the datasheet
   6  * does use this as an example for all illustrations and more importantly:
   7  * that is the crystal input on boards it is currently used on.
   8  *
   9  * Copyright (C) 2009 Texas Instruments Incorporated. http://www.ti.com/
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  *
  15  */
  16 #include <linux/kernel.h>
  17 #include <linux/clk.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/i2c.h>
  20 #include <linux/module.h>
  21
  22 #include <mach/clock.h>
  23 #include <mach/cdce949.h>
  24
  25 #include "clock.h"
  26
  27 static struct i2c_client *cdce_i2c_client;
  28 static DEFINE_MUTEX(cdce_mutex);
  29
  30 /* CDCE register descriptor */
  31 struct cdce_reg {
  32         u8      addr;
  33         u8      val;
  34 };
  35
  36 /* Per-Output (Y1, Y2 etc.) frequency descriptor */
  37 struct cdce_freq {
  38         /* Frequency in KHz */
  39         unsigned long frequency;
  40         /*
  41          * List of registers to program to obtain a particular frequency.
  42          * 0x0 in register address and value is the end of list marker.
  43          */
  44         struct cdce_reg *reglist;
  45 };
  46
  47 #define CDCE_FREQ_TABLE_ENTRY(line, out)                \
  48 {                                                       \
  49         .reglist        = cdce_y ##line## _ ##out,              \
  50         .frequency      = out,                          \
  51 }
  52
  53 /* List of CDCE outputs  */
  54 struct cdce_output {
  55         /* List of frequencies on this output */
  56         struct cdce_freq *freq_table;
  57         /* Number of possible frequencies */
  58         int size;
  59 };
  60
  61 /*
  62  * Finding out the values to program into CDCE949 registers for a particular
  63  * frequency output is not a simple calculation. Have a look at the datasheet
  64  * for the details. There is desktop software available to help users with
  65  * the calculations. Here, we just depend on the output of that software
  66  * (or hand calculations) instead trying to runtime calculate the register
  67  * values and inflicting misery on ourselves.
  68  */
  69 static struct cdce_reg cdce_y1_148500[] = {
  70         { 0x13, 0x00 },
  71         /* program PLL1_0 multiplier */
  72         { 0x18, 0xaf },
  73         { 0x19, 0x50 },
  74         { 0x1a, 0x02 },
  75         { 0x1b, 0xc9 },
  76         /* program PLL1_11 multiplier */
  77         { 0x1c, 0x00 },
  78         { 0x1d, 0x40 },
  79         { 0x1e, 0x02 },
  80         { 0x1f, 0xc9 },
  81         /* output state selection */
  82         { 0x15, 0x00 },
  83         { 0x14, 0xef },
  84         /* switch MUX to PLL1 output */
  85         { 0x14, 0x6f },
  86         { 0x16, 0x06 },
  87         /* set P2DIV divider, P3DIV and input crystal */
  88         { 0x17, 0x06 },
  89         { 0x01, 0x00 },
  90         { 0x05, 0x48 },
  91         { 0x02, 0x80 },
  92         /* enable and disable PLL */
  93         { 0x02, 0xbc },
  94         { 0x03, 0x01 },
  95         { },
  96 };
  97
  98 static struct cdce_reg cdce_y1_74250[] = {
  99         { 0x13, 0x00 },
 100         { 0x18, 0xaf },
 101         { 0x19, 0x50 },
 102         { 0x1a, 0x02 },
 103         { 0x1b, 0xc9 },
 104         { 0x1c, 0x00 },
 105         { 0x1d, 0x40 },
 106         { 0x1e, 0x02 },
 107         { 0x1f, 0xc9 },
 108         /* output state selection */
 109         { 0x15, 0x00 },
 110         { 0x14, 0xef },
 111         /* switch MUX to PLL1 output */
 112         { 0x14, 0x6f },
 113         { 0x16, 0x06 },
 114         /* set P2DIV divider, P3DIV and input crystal */
 115         { 0x17, 0x06 },
 116         { 0x01, 0x00 },
 117         { 0x05, 0x48 },
 118         { 0x02, 0x80 },
 119         /* enable and disable PLL */
 120         { 0x02, 0xbc },
 121         { 0x03, 0x02 },
 122         { },
 123 };
 124
 125 static struct cdce_reg cdce_y1_27000[] = {
 126         { 0x13, 0x00 },
 127         { 0x18, 0x00 },
 128         { 0x19, 0x40 },
 129         { 0x1a, 0x02 },
 130         { 0x1b, 0x08 },
 131         { 0x1c, 0x00 },
 132         { 0x1d, 0x40 },
 133         { 0x1e, 0x02 },
 134         { 0x1f, 0x08 },
 135         { 0x15, 0x02 },
 136         { 0x14, 0xed },
 137         { 0x16, 0x01 },
 138         { 0x17, 0x01 },
 139         { 0x01, 0x00 },
 140         { 0x05, 0x50 },
 141         { 0x02, 0xb4 },
 142         { 0x03, 0x01 },
 143         { },
 144 };
 145
 146 static struct cdce_freq cdce_y1_freqs[] = {
 147         CDCE_FREQ_TABLE_ENTRY(1, 148500),
 148         CDCE_FREQ_TABLE_ENTRY(1, 74250),
 149         CDCE_FREQ_TABLE_ENTRY(1, 27000),
 150 };
 151
 152 static struct cdce_reg cdce_y5_13500[] = {
 153         { 0x27, 0x08 },
 154         { 0x28, 0x00 },
 155         { 0x29, 0x40 },
 156         { 0x2a, 0x02 },
 157         { 0x2b, 0x08 },
 158         { 0x24, 0x6f },
 159         { },
 160 };
 161
 162 static struct cdce_reg cdce_y5_16875[] = {
 163         { 0x27, 0x08 },
 164         { 0x28, 0x9f },
 165         { 0x29, 0xb0 },
 166         { 0x2a, 0x02 },
 167         { 0x2b, 0x89 },
 168         { 0x24, 0x6f },
 169         { },
 170 };
 171
 172 static struct cdce_reg cdce_y5_27000[] = {
 173         { 0x27, 0x04 },
 174         { 0x28, 0x00 },
 175         { 0x29, 0x40 },
 176         { 0x2a, 0x02 },
 177         { 0x2b, 0x08 },
 178         { 0x24, 0x6f },
 179         { },
 180 };
 181 static struct cdce_reg cdce_y5_54000[] = {
 182         { 0x27, 0x04 },
 183         { 0x28, 0xff },
 184         { 0x29, 0x80 },
 185         { 0x2a, 0x02 },
 186         { 0x2b, 0x07 },
 187         { 0x24, 0x6f },
 188         { },
 189 };
 190
 191 static struct cdce_reg cdce_y5_81000[] = {
 192         { 0x27, 0x02 },
 193         { 0x28, 0xbf },
 194         { 0x29, 0xa0 },
 195         { 0x2a, 0x03 },
 196         { 0x2b, 0x0a },
 197         { 0x24, 0x6f },
 198         { },
 199 };
 200
 201 static struct cdce_freq cdce_y5_freqs[] = {
 202         CDCE_FREQ_TABLE_ENTRY(5, 13500),
 203         CDCE_FREQ_TABLE_ENTRY(5, 16875),
 204         CDCE_FREQ_TABLE_ENTRY(5, 27000),
 205         CDCE_FREQ_TABLE_ENTRY(5, 54000),
 206         CDCE_FREQ_TABLE_ENTRY(5, 81000),
 207 };
 208
 209
 210 static struct cdce_output output_list[] = {
 211         [1]     = { cdce_y1_freqs, ARRAY_SIZE(cdce_y1_freqs) },
 212         [5]     = { cdce_y5_freqs, ARRAY_SIZE(cdce_y5_freqs) },
 213 };
 214
 215 int cdce_set_rate(struct clk *clk, unsigned long rate)
 216 {
 217         int i, ret = 0;
 218         struct cdce_freq *freq_table = output_list[clk->lpsc].freq_table;
 219         struct cdce_reg  *regs = NULL;
 220
 221         if (!cdce_i2c_client)
 222                 return -ENODEV;
 223
 224         if (!freq_table)
 225                 return -EINVAL;
 226
 227         for (i = 0; i < output_list[clk->lpsc].size; i++) {
 228                 if (freq_table[i].frequency == rate / 1000) {
 229                         regs = freq_table[i].reglist;
 230                         break;
 231                 }
 232         }
 233
 234         if (!regs)
 235                 return -EINVAL;
 236
 237         mutex_lock(&cdce_mutex);
 238         for (i = 0; regs[i].addr; i++) {
 239                 ret = i2c_smbus_write_byte_data(cdce_i2c_client,
 240                                         regs[i].addr | 0x80, regs[i].val);
 241                 if (ret)
 242                         break;
 243         }
 244         mutex_unlock(&cdce_mutex);
 245
 246         if (!ret)
 247                 clk->rate = rate;
 248
 249         return ret;
 250 }
 251
 252 static int cdce_probe(struct i2c_client *client,
 253                                         const struct i2c_device_id *id)
 254 {
 255         cdce_i2c_client = client;
 256         return 0;
 257 }
 258
 259 static int cdce_remove(struct i2c_client *client)
 260 {
 261         cdce_i2c_client = NULL;
 262         return 0;
 263 }
 264
 265 static const struct i2c_device_id cdce_id[] = {
 266         {"cdce949", 0},
 267         {},
 268 };
 269 MODULE_DEVICE_TABLE(i2c, cdce_id);
 270
 271 static struct i2c_driver cdce_driver = {
 272         .driver = {
 273                 .owner  = THIS_MODULE,
 274                 .name   = "cdce949",
 275         },
 276         .probe          = cdce_probe,
 277         .remove         = cdce_remove,
 278         .id_table       = cdce_id,
 279 };
 280
 281 static int __init cdce_init(void)
 282 {
 283         return i2c_add_driver(&cdce_driver);
 284 }
 285 subsys_initcall(cdce_init);
 286
 287 static void __exit cdce_exit(void)
 288 {
 289         i2c_del_driver(&cdce_driver);
 290 }
 291 module_exit(cdce_exit);
 292
 293 MODULE_AUTHOR("Texas Instruments");
 294 MODULE_DESCRIPTION("CDCE949 clock synthesizer driver");
 295 MODULE_LICENSE("GPL v2");