diff options
Diffstat (limited to 'arch/arm/mach-davinci/cdce949.c')
| -rw-r--r-- | arch/arm/mach-davinci/cdce949.c | 293 | 
1 files changed, 293 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/cdce949.c b/arch/arm/mach-davinci/cdce949.c new file mode 100644 index 00000000000..aec37569054 --- /dev/null +++ b/arch/arm/mach-davinci/cdce949.c @@ -0,0 +1,293 @@ +/* + * 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 <mach/clock.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 __devexit 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		= __devexit_p(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");  |