/*
* TI CDCE949 clock synthesizer driver
*
* Note: This implementation assumes an input of 27MHz to the CDCE.
* This is by no means constrained by CDCE hardware although the datasheet
* does use this as an example for all illustrations and more importantly:
* that is the crystal input on boards it is currently used on.
*
* Copyright (C) 2009 Texas Instruments Incorporated. http://www.ti.com/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <mach/clock.h>
#include <mach/cdce949.h>
#include "clock.h"
static struct i2c_client *cdce_i2c_client;
static DEFINE_MUTEX(cdce_mutex);
/* CDCE register descriptor */
struct cdce_reg {
u8 addr;
u8 val;
};
/* Per-Output (Y1, Y2 etc.) frequency descriptor */
struct cdce_freq {
/* Frequency in KHz */
unsigned long frequency;
/*
* List of registers to program to obtain a particular frequency.
* 0x0 in register address and value is the end of list marker.
*/
struct cdce_reg *reglist;
};
#define CDCE_FREQ_TABLE_ENTRY(line, out) \
{ \
.reglist = cdce_y ##line## _ ##out, \
.frequency = out, \
}
/* List of CDCE outputs */
struct cdce_output {
/* List of frequencies on this output */
struct cdce_freq *freq_table;
/* Number of possible frequencies */
int size;
};
/*
* Finding out the values to program into CDCE949 registers for a particular
* frequency output is not a simple calculation. Have a look at the datasheet
* for the details. There is desktop software available to help users with
* the calculations. Here, we just depend on the output of that software
* (or hand calculations) instead trying to runtime calculate the register
* values and inflicting misery on ourselves.
*/
static struct cdce_reg cdce_y1_148500[] = {
{ 0x13, 0x00 },
/* program PLL1_0 multiplier */
{ 0x18, 0xaf },
{ 0x19, 0x50 },
{ 0x1a, 0x02 },
{ 0x1b, 0xc9 },
/* program PLL1_11 multiplier */
{ 0x1c, 0x00 },
{ 0x1d, 0x40 },
{ 0x1e, 0x02 },
{ 0x1f, 0xc9 },
/* output state selection */
{ 0x15, 0x00 },
{ 0x14, 0xef },
/* switch MUX to PLL1 output */
{ 0x14, 0x6f },
{ 0x16, 0x06 },
/* set P2DIV divider, P3DIV and input crystal */
{ 0x17, 0x06 },
{ 0x01, 0x00 },
{ 0x05, 0x48 },
{ 0x02, 0x80 },
/* enable and disable PLL */
{ 0x02, 0xbc },
{ 0x03, 0x01 },
{ },
};
static struct cdce_reg cdce_y1_74250[] = {
{ 0x13, 0x00 },
{ 0x18, 0xaf },
{ 0x19, 0x50 },
{ 0x1a, 0x02 },
{ 0x1b, 0xc9 },
{ 0x1c, 0x00 },
{ 0x1d, 0x40 },
{ 0x1e, 0x02 },
{ 0x1f, 0xc9 },
/* output state selection */
{ 0x15, 0x00 },
{ 0x14, 0xef },
/* switch MUX to PLL1 output */
{ 0x14, 0x6f },
{ 0x16, 0x06 },
/* set P2DIV divider, P3DIV and input crystal */
{ 0x17, 0x06 },
{ 0x01, 0x00 },
{ 0x05, 0x48 },
{ 0x02, 0x80 },
/* enable and disable PLL */
{ 0x02, 0xbc },
{ 0x03, 0x02 },
{ },
};
static struct cdce_reg cdce_y1_27000[] = {
{ 0x13, 0x00 },
{ 0x18, 0x00 },
{ 0x19, 0x40 },
{ 0x1a, 0x02 },
{ 0x1b, 0x08 },
{ 0x1c, 0x00 },
{ 0x1d, 0x40 },
{ 0x1e, 0x02 },
{ 0x1f, 0x08 },
{ 0x15, 0x02 },
{ 0x14, 0xed },
{ 0x16, 0x01 },
{ 0x17, 0x01 },
{ 0x01, 0x00 },
{ 0x05, 0x50 },
{ 0x02, 0xb4 },
{ 0x03, 0x01 },
{ },
};
static struct cdce_freq cdce_y1_freqs[] = {
CDCE_FREQ_TABLE_ENTRY(1, 148500),
CDCE_FREQ_TABLE_ENTRY(1, 74250),
CDCE_FREQ_TABLE_ENTRY(1, 27000),
};
static struct cdce_reg cdce_y5_13500[] = {
{ 0x27, 0x08 },
{ 0x28, 0x00 },
{ 0x29, 0x40 },
{ 0x2a, 0x02 },
{ 0x2b, 0x08 },
{ 0x24, 0x6f },
{ },
};
static struct cdce_reg cdce_y5_16875[] = {
{ 0x27, 0x08 },
{ 0x28, 0x9f },
{ 0x29, 0xb0 },
{ 0x2a, 0x02 },
{ 0x2b, 0x89 },
{ 0x24, 0x6f },
{ },
};
static struct cdce_reg cdce_y5_27000[] = {
{ 0x27, 0x04 },
{ 0x28, 0x00 },
{ 0x29, 0x40 },
{ 0x2a, 0x02 },
{ 0x2b, 0x08 },
{ 0x24, 0x6f },
{ },
};
static struct cdce_reg cdce_y5_54000[] = {
{ 0x27, 0x04 },
{ 0x28, 0xff },
{ 0x29, 0x80 },
{ 0x2a, 0x02 },
{ 0x2b, 0x07 },
{ 0x24, 0x6f },
{ },
};
static struct cdce_reg cdce_y5_81000[] = {
{ 0x27, 0x02 },
{ 0x28, 0xbf },
{ 0x29, 0xa0 },
{ 0x2a, 0x03 },
{ 0x2b, 0x0a },
{ 0x24, 0x6f },
{ },
};
static struct cdce_freq cdce_y5_freqs[] = {
CDCE_FREQ_TABLE_ENTRY(5, 13500),
CDCE_FREQ_TABLE_ENTRY(5, 16875),
CDCE_FREQ_TABLE_ENTRY(5, 27000),
CDCE_FREQ_TABLE_ENTRY(5, 54000),
CDCE_FREQ_TABLE_ENTRY(5, 81000),
};
static struct cdce_output output_list[] = {
[1] = { cdce_y1_freqs, ARRAY_SIZE(cdce_y1_freqs) },
[5] = { cdce_y5_freqs, ARRAY_SIZE(cdce_y5_freqs) },
};
int cdce_set_rate(struct clk *clk, unsigned long rate)
{
int i, ret = 0;
struct cdce_freq *freq_table = output_list[clk->lpsc].freq_table;
struct cdce_reg *regs = NULL;
if (!cdce_i2c_client)
return -ENODEV;
if (!freq_table)
return -EINVAL;
for (i = 0; i < output_list[clk->lpsc].size; i++) {
if (freq_table[i].frequency == rate / 1000) {
regs = freq_table[i].reglist;
break;
}
}
if (!regs)
return -EINVAL;
mutex_lock(&cdce_mutex);
for (i = 0; regs[i].addr; i++) {
ret = i2c_smbus_write_byte_data(cdce_i2c_client,
regs[i].addr | 0x80, regs[i].val);
if (ret)
break;
}
mutex_unlock(&cdce_mutex);
if (!ret)
clk->rate = rate;
return ret;
}
static int cdce_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
cdce_i2c_client = client;
return 0;
}
static int cdce_remove(struct i2c_client *client)
{
cdce_i2c_client = NULL;
return 0;
}
static const struct i2c_device_id cdce_id[] = {
{"cdce949", 0},
{},
};
MODULE_DEVICE_TABLE(i2c, cdce_id);
static struct i2c_driver cdce_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "cdce949",
},
.probe = cdce_probe,
.remove = cdce_remove,
.id_table = cdce_id,
};
static int __init cdce_init(void)
{
return i2c_add_driver(&cdce_driver);
}
subsys_initcall(cdce_init);
static void __exit cdce_exit(void)
{
i2c_del_driver(&cdce_driver);
}
module_exit(cdce_exit);
MODULE_AUTHOR("Texas Instruments");
MODULE_DESCRIPTION("CDCE949 clock synthesizer driver");
MODULE_LICENSE("GPL v2");
