[deliverable/linux.git] / drivers / misc / eeprom / eeprom_93cx6.c

/*
 * Copyright (C) 2004 - 2006 rt2x00 SourceForge Project
 * <http://rt2x00.serialmonkey.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * Module: eeprom_93cx6
 * Abstract: EEPROM reader routines for 93cx6 chipsets.
 * Supported chipsets: 93c46 & 93c66.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/eeprom_93cx6.h>

MODULE_AUTHOR("http://rt2x00.serialmonkey.com");
MODULE_VERSION("1.0");
MODULE_DESCRIPTION("EEPROM 93cx6 chip driver");
MODULE_LICENSE("GPL");

static inline void eeprom_93cx6_pulse_high(struct eeprom_93cx6 *eeprom)
{
	eeprom->reg_data_clock = 1;
	eeprom->register_write(eeprom);

	/*
	 * Add a short delay for the pulse to work.
	 * According to the specifications the "maximum minimum"
	 * time should be 450ns.
	 */
	ndelay(450);
}

static inline void eeprom_93cx6_pulse_low(struct eeprom_93cx6 *eeprom)
{
	eeprom->reg_data_clock = 0;
	eeprom->register_write(eeprom);

	/*
	 * Add a short delay for the pulse to work.
	 * According to the specifications the "maximum minimum"
	 * time should be 450ns.
	 */
	ndelay(450);
}

static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom)
{
	/*
	 * Clear all flags, and enable chip select.
	 */
	eeprom->register_read(eeprom);
	eeprom->reg_data_in = 0;
	eeprom->reg_data_out = 0;
	eeprom->reg_data_clock = 0;
	eeprom->reg_chip_select = 1;
	eeprom->drive_data = 1;
	eeprom->register_write(eeprom);

	/*
	 * kick a pulse.
	 */
	eeprom_93cx6_pulse_high(eeprom);
	eeprom_93cx6_pulse_low(eeprom);
}

static void eeprom_93cx6_cleanup(struct eeprom_93cx6 *eeprom)
{
	/*
	 * Clear chip_select and data_in flags.
	 */
	eeprom->register_read(eeprom);
	eeprom->reg_data_in = 0;
	eeprom->reg_chip_select = 0;
	eeprom->register_write(eeprom);

	/*
	 * kick a pulse.
	 */
	eeprom_93cx6_pulse_high(eeprom);
	eeprom_93cx6_pulse_low(eeprom);
}

static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom,
	const u16 data, const u16 count)
{
	unsigned int i;

	eeprom->register_read(eeprom);

	/*
	 * Clear data flags.
	 */
	eeprom->reg_data_in = 0;
	eeprom->reg_data_out = 0;
	eeprom->drive_data = 1;

	/*
	 * Start writing all bits.
	 */
	for (i = count; i > 0; i--) {
		/*
		 * Check if this bit needs to be set.
		 */
		eeprom->reg_data_in = !!(data & (1 << (i - 1)));

		/*
		 * Write the bit to the eeprom register.
		 */
		eeprom->register_write(eeprom);

		/*
		 * Kick a pulse.
		 */
		eeprom_93cx6_pulse_high(eeprom);
		eeprom_93cx6_pulse_low(eeprom);
	}

	eeprom->reg_data_in = 0;
	eeprom->register_write(eeprom);
}

static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom,
	u16 *data, const u16 count)
{
	unsigned int i;
	u16 buf = 0;

	eeprom->register_read(eeprom);

	/*
	 * Clear data flags.
	 */
	eeprom->reg_data_in = 0;
	eeprom->reg_data_out = 0;
	eeprom->drive_data = 0;

	/*
	 * Start reading all bits.
	 */
	for (i = count; i > 0; i--) {
		eeprom_93cx6_pulse_high(eeprom);

		eeprom->register_read(eeprom);

		/*
		 * Clear data_in flag.
		 */
		eeprom->reg_data_in = 0;

		/*
		 * Read if the bit has been set.
		 */
		if (eeprom->reg_data_out)
			buf |= (1 << (i - 1));

		eeprom_93cx6_pulse_low(eeprom);
	}

	*data = buf;
}

/**
 * eeprom_93cx6_read - Read multiple words from eeprom
 * @eeprom: Pointer to eeprom structure
 * @word: Word index from where we should start reading
 * @data: target pointer where the information will have to be stored
 *
 * This function will read the eeprom data as host-endian word
 * into the given data pointer.
 */
void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom, const u8 word,
	u16 *data)
{
	u16 command;

	/*
	 * Initialize the eeprom register
	 */
	eeprom_93cx6_startup(eeprom);

	/*
	 * Select the read opcode and the word to be read.
	 */
	command = (PCI_EEPROM_READ_OPCODE << eeprom->width) | word;
	eeprom_93cx6_write_bits(eeprom, command,
		PCI_EEPROM_WIDTH_OPCODE + eeprom->width);

	/*
	 * Read the requested 16 bits.
	 */
	eeprom_93cx6_read_bits(eeprom, data, 16);

	/*
	 * Cleanup eeprom register.
	 */
	eeprom_93cx6_cleanup(eeprom);
}
EXPORT_SYMBOL_GPL(eeprom_93cx6_read);

/**
 * eeprom_93cx6_multiread - Read multiple words from eeprom
 * @eeprom: Pointer to eeprom structure
 * @word: Word index from where we should start reading
 * @data: target pointer where the information will have to be stored
 * @words: Number of words that should be read.
 *
 * This function will read all requested words from the eeprom,
 * this is done by calling eeprom_93cx6_read() multiple times.
 * But with the additional change that while the eeprom_93cx6_read
 * will return host ordered bytes, this method will return little
 * endian words.
 */
void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word,
	__le16 *data, const u16 words)
{
	unsigned int i;
	u16 tmp;

	for (i = 0; i < words; i++) {
		tmp = 0;
		eeprom_93cx6_read(eeprom, word + i, &tmp);
		data[i] = cpu_to_le16(tmp);
	}
}
EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread);

/**
 * eeprom_93cx6_wren - set the write enable state
 * @eeprom: Pointer to eeprom structure
 * @enable: true to enable writes, otherwise disable writes
 *
 * Set the EEPROM write enable state to either allow or deny
 * writes depending on the @enable value.
 */
void eeprom_93cx6_wren(struct eeprom_93cx6 *eeprom, bool enable)
{
	u16 command;

	/* start the command */
	eeprom_93cx6_startup(eeprom);

	/* create command to enable/disable */

	command = enable ? PCI_EEPROM_EWEN_OPCODE : PCI_EEPROM_EWDS_OPCODE;
	command <<= (eeprom->width - 2);

	eeprom_93cx6_write_bits(eeprom, command,
				PCI_EEPROM_WIDTH_OPCODE + eeprom->width);

	eeprom_93cx6_cleanup(eeprom);
}
EXPORT_SYMBOL_GPL(eeprom_93cx6_wren);

/**
 * eeprom_93cx6_write - write data to the EEPROM
 * @eeprom: Pointer to eeprom structure
 * @addr: Address to write data to.
 * @data: The data to write to address @addr.
 *
 * Write the @data to the specified @addr in the EEPROM and
 * waiting for the device to finish writing.
 *
 * Note, since we do not expect large number of write operations
 * we delay in between parts of the operation to avoid using excessive
 * amounts of CPU time busy waiting.
 */
void eeprom_93cx6_write(struct eeprom_93cx6 *eeprom, u8 addr, u16 data)
{
	int timeout = 100;
	u16 command;

	/* start the command */
	eeprom_93cx6_startup(eeprom);

	command = PCI_EEPROM_WRITE_OPCODE << eeprom->width;
	command |= addr;

	/* send write command */
	eeprom_93cx6_write_bits(eeprom, command,
				PCI_EEPROM_WIDTH_OPCODE + eeprom->width);

	/* send data */
	eeprom_93cx6_write_bits(eeprom, data, 16);

	/* get ready to check for busy */
	eeprom->drive_data = 0;
	eeprom->reg_chip_select = 1;
	eeprom->register_write(eeprom);

	/* wait at-least 250ns to get DO to be the busy signal */
	usleep_range(1000, 2000);

	/* wait for DO to go high to signify finish */

	while (true) {
		eeprom->register_read(eeprom);

		if (eeprom->reg_data_out)
			break;

		usleep_range(1000, 2000);

		if (--timeout <= 0) {
			printk(KERN_ERR "%s: timeout\n", __func__);
			break;
		}
	}

	eeprom_93cx6_cleanup(eeprom);
}
EXPORT_SYMBOL_GPL(eeprom_93cx6_write);
Commit	Line	Data
9467d64b	1	/*
654087fa AA	2	* Copyright (C) 2004 - 2006 rt2x00 SourceForge Project
	3	* <http://rt2x00.serialmonkey.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; either version 2 of the License, or
	8	* (at your option) any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* Module: eeprom_93cx6
	16	* Abstract: EEPROM reader routines for 93cx6 chipsets.
	17	* Supported chipsets: 93c46 & 93c66.
9467d64b ID	18	*/
	19
	20	#include <linux/kernel.h>
	21	#include <linux/module.h>
9467d64b ID	22	#include <linux/delay.h>
	23	#include <linux/eeprom_93cx6.h>
	24
	25	MODULE_AUTHOR("http://rt2x00.serialmonkey.com");
	26	MODULE_VERSION("1.0");
	27	MODULE_DESCRIPTION("EEPROM 93cx6 chip driver");
	28	MODULE_LICENSE("GPL");
	29
	30	static inline void eeprom_93cx6_pulse_high(struct eeprom_93cx6 *eeprom)
	31	{
	32	eeprom->reg_data_clock = 1;
	33	eeprom->register_write(eeprom);
4b914dc0 ID	34
	35	/*
	36	* Add a short delay for the pulse to work.
7e9400f1 JL	37	* According to the specifications the "maximum minimum"
7e9400f1 JL	38	* time should be 450ns.
4b914dc0	39	*/
7e9400f1	40	ndelay(450);
9467d64b ID	41	}
	42
	43	static inline void eeprom_93cx6_pulse_low(struct eeprom_93cx6 *eeprom)
	44	{
	45	eeprom->reg_data_clock = 0;
	46	eeprom->register_write(eeprom);
4b914dc0 ID	47
	48	/*
	49	* Add a short delay for the pulse to work.
8abd531e FR	50	* According to the specifications the "maximum minimum"
8abd531e FR	51	* time should be 450ns.
4b914dc0	52	*/
8abd531e	53	ndelay(450);
9467d64b ID	54	}
	55
	56	static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom)
	57	{
	58	/*
	59	* Clear all flags, and enable chip select.
	60	*/
	61	eeprom->register_read(eeprom);
	62	eeprom->reg_data_in = 0;
	63	eeprom->reg_data_out = 0;
	64	eeprom->reg_data_clock = 0;
	65	eeprom->reg_chip_select = 1;
b30f8bdc	66	eeprom->drive_data = 1;
9467d64b ID	67	eeprom->register_write(eeprom);
	68
	69	/*
	70	* kick a pulse.
	71	*/
	72	eeprom_93cx6_pulse_high(eeprom);
	73	eeprom_93cx6_pulse_low(eeprom);
	74	}
	75
	76	static void eeprom_93cx6_cleanup(struct eeprom_93cx6 *eeprom)
	77	{
	78	/*
	79	* Clear chip_select and data_in flags.
	80	*/
	81	eeprom->register_read(eeprom);
	82	eeprom->reg_data_in = 0;
	83	eeprom->reg_chip_select = 0;
	84	eeprom->register_write(eeprom);
	85
	86	/*
	87	* kick a pulse.
	88	*/
	89	eeprom_93cx6_pulse_high(eeprom);
	90	eeprom_93cx6_pulse_low(eeprom);
	91	}
	92
	93	static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom,
	94	const u16 data, const u16 count)
	95	{
	96	unsigned int i;
	97
	98	eeprom->register_read(eeprom);
	99
	100	/*
	101	* Clear data flags.
	102	*/
	103	eeprom->reg_data_in = 0;
	104	eeprom->reg_data_out = 0;
b30f8bdc	105	eeprom->drive_data = 1;
9467d64b ID	106
	107	/*
	108	* Start writing all bits.
	109	*/
	110	for (i = count; i > 0; i--) {
	111	/*
	112	* Check if this bit needs to be set.
	113	*/
	114	eeprom->reg_data_in = !!(data & (1 << (i - 1)));
	115
	116	/*
	117	* Write the bit to the eeprom register.
	118	*/
	119	eeprom->register_write(eeprom);
	120
	121	/*
	122	* Kick a pulse.
	123	*/
	124	eeprom_93cx6_pulse_high(eeprom);
	125	eeprom_93cx6_pulse_low(eeprom);
	126	}
	127
	128	eeprom->reg_data_in = 0;
	129	eeprom->register_write(eeprom);
	130	}
	131
	132	static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom,
	133	u16 *data, const u16 count)
	134	{
	135	unsigned int i;
	136	u16 buf = 0;
	137
	138	eeprom->register_read(eeprom);
	139
	140	/*
	141	* Clear data flags.
	142	*/
	143	eeprom->reg_data_in = 0;
	144	eeprom->reg_data_out = 0;
b30f8bdc	145	eeprom->drive_data = 0;
9467d64b ID	146
	147	/*
	148	* Start reading all bits.
	149	*/
	150	for (i = count; i > 0; i--) {
	151	eeprom_93cx6_pulse_high(eeprom);
	152
	153	eeprom->register_read(eeprom);
	154
	155	/*
	156	* Clear data_in flag.
	157	*/
	158	eeprom->reg_data_in = 0;
	159
	160	/*
	161	* Read if the bit has been set.
	162	*/
	163	if (eeprom->reg_data_out)
	164	buf \|= (1 << (i - 1));
	165
	166	eeprom_93cx6_pulse_low(eeprom);
	167	}
	168
	169	*data = buf;
	170	}
	171
	172	/**
	173	* eeprom_93cx6_read - Read multiple words from eeprom
	174	* @eeprom: Pointer to eeprom structure
	175	* @word: Word index from where we should start reading
	176	* @data: target pointer where the information will have to be stored
	177	*
	178	* This function will read the eeprom data as host-endian word
	179	* into the given data pointer.
	180	*/
	181	void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom, const u8 word,
	182	u16 *data)
	183	{
	184	u16 command;
	185
	186	/*
	187	* Initialize the eeprom register
	188	*/
	189	eeprom_93cx6_startup(eeprom);
	190
	191	/*
	192	* Select the read opcode and the word to be read.
	193	*/
	194	command = (PCI_EEPROM_READ_OPCODE << eeprom->width) \| word;
	195	eeprom_93cx6_write_bits(eeprom, command,
	196	PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
	197
	198	/*
	199	* Read the requested 16 bits.
	200	*/
	201	eeprom_93cx6_read_bits(eeprom, data, 16);
	202
	203	/*
	204	* Cleanup eeprom register.
	205	*/
	206	eeprom_93cx6_cleanup(eeprom);
	207	}
	208	EXPORT_SYMBOL_GPL(eeprom_93cx6_read);
	209
210	/**
211	* eeprom_93cx6_multiread - Read multiple words from eeprom
212	* @eeprom: Pointer to eeprom structure
213	* @word: Word index from where we should start reading
214	* @data: target pointer where the information will have to be stored
215	* @words: Number of words that should be read.
216	*
217	* This function will read all requested words from the eeprom,
218	* this is done by calling eeprom_93cx6_read() multiple times.
219	* But with the additional change that while the eeprom_93cx6_read
220	* will return host ordered bytes, this method will return little
221	* endian words.
222	*/
223	void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word,
224	__le16 *data, const u16 words)
225	{
226	unsigned int i;
227	u16 tmp;
228
229	for (i = 0; i < words; i++) {
230	tmp = 0;
231	eeprom_93cx6_read(eeprom, word + i, &tmp);
232	data[i] = cpu_to_le16(tmp);
233	}
234	}
235	EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread);
236
072bc801 BD	237	/**
	238	* eeprom_93cx6_wren - set the write enable state
	239	* @eeprom: Pointer to eeprom structure
	240	* @enable: true to enable writes, otherwise disable writes
	241	*
	242	* Set the EEPROM write enable state to either allow or deny
	243	* writes depending on the @enable value.
	244	*/
	245	void eeprom_93cx6_wren(struct eeprom_93cx6 *eeprom, bool enable)
	246	{
	247	u16 command;
	248
	249	/* start the command */
	250	eeprom_93cx6_startup(eeprom);
	251
	252	/* create command to enable/disable */
	253
	254	command = enable ? PCI_EEPROM_EWEN_OPCODE : PCI_EEPROM_EWDS_OPCODE;
	255	command <<= (eeprom->width - 2);
	256
	257	eeprom_93cx6_write_bits(eeprom, command,
	258	PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
	259
	260	eeprom_93cx6_cleanup(eeprom);
	261	}
	262	EXPORT_SYMBOL_GPL(eeprom_93cx6_wren);
	263
	264	/**
	265	* eeprom_93cx6_write - write data to the EEPROM
	266	* @eeprom: Pointer to eeprom structure
	267	* @addr: Address to write data to.
	268	* @data: The data to write to address @addr.
	269	*
	270	* Write the @data to the specified @addr in the EEPROM and
	271	* waiting for the device to finish writing.
	272	*
	273	* Note, since we do not expect large number of write operations
	274	* we delay in between parts of the operation to avoid using excessive
	275	* amounts of CPU time busy waiting.
	276	*/
	277	void eeprom_93cx6_write(struct eeprom_93cx6 *eeprom, u8 addr, u16 data)
	278	{
	279	int timeout = 100;
	280	u16 command;
	281
	282	/* start the command */
	283	eeprom_93cx6_startup(eeprom);
	284
	285	command = PCI_EEPROM_WRITE_OPCODE << eeprom->width;
	286	command \|= addr;
	287
	288	/* send write command */
	289	eeprom_93cx6_write_bits(eeprom, command,
	290	PCI_EEPROM_WIDTH_OPCODE + eeprom->width);
	291
	292	/* send data */
	293	eeprom_93cx6_write_bits(eeprom, data, 16);
	294
	295	/* get ready to check for busy */
	296	eeprom->drive_data = 0;
	297	eeprom->reg_chip_select = 1;
	298	eeprom->register_write(eeprom);
	299
	300	/* wait at-least 250ns to get DO to be the busy signal */
301	usleep_range(1000, 2000);
302
303	/* wait for DO to go high to signify finish */
304
305	while (true) {
306	eeprom->register_read(eeprom);
307
308	if (eeprom->reg_data_out)
309	break;
310
311	usleep_range(1000, 2000);
312
313	if (--timeout <= 0) {
314	printk(KERN_ERR "%s: timeout\n", __func__);
315	break;
316	}
317	}
318
319	eeprom_93cx6_cleanup(eeprom);
320	}
321	EXPORT_SYMBOL_GPL(eeprom_93cx6_write);