1/******************************************************************************
2 *
3 * Filename: eeprom.c
4 *
5 * Instantiation of eeprom routines
6 *
7 * Revision information:
8 *
9 * 28AUG2004	kb_admin	initial creation - adapted from Atmel sources
10 * 12JAN2005	kb_admin	fixed clock generation, write polling, init
11 *
12 * BEGIN_KBDD_BLOCK
13 * No warranty, expressed or implied, is included with this software.  It is
14 * provided "AS IS" and no warranty of any kind including statutory or aspects
15 * relating to merchantability or fitness for any purpose is provided.  All
16 * intellectual property rights of others is maintained with the respective
17 * owners.  This software is not copyrighted and is intended for reference
18 * only.
19 * END_BLOCK
20 *
21 * $FreeBSD$
22 *****************************************************************************/
23
24#include "at91rm9200_lowlevel.h"
25#include "at91rm9200.h"
26#include "lib.h"
27
28/******************************* GLOBALS *************************************/
29
30
31/*********************** PRIVATE FUNCTIONS/DATA ******************************/
32
33
34/* Use a macro to calculate the TWI clock generator value to save code space. */
35#define AT91C_TWSI_CLOCK	100000
36#define TWSI_EEPROM_ADDRESS	0x50
37
38#define TWI_CLK_BASE_DIV	((AT91C_MASTER_CLOCK/(4*AT91C_TWSI_CLOCK)) - 2)
39#define SET_TWI_CLOCK	((0x00010000) | (TWI_CLK_BASE_DIV) | (TWI_CLK_BASE_DIV << 8))
40
41
42/*************************** GLOBAL FUNCTIONS ********************************/
43
44
45/*
46 * .KB_C_FN_DEFINITION_START
47 * void InitEEPROM(void)
48 *  This global function initializes the EEPROM interface (TWI).  Intended
49 * to be called a single time.
50 * .KB_C_FN_DEFINITION_END
51 */
52void
53InitEEPROM(void)
54{
55
56	AT91PS_TWI twiPtr = (AT91PS_TWI)AT91C_BASE_TWI;
57
58	AT91PS_PIO pPio = (AT91PS_PIO)AT91C_BASE_PIOA;
59	AT91PS_PMC pPMC = (AT91PS_PMC)AT91C_BASE_PMC;
60
61	pPio->PIO_ASR = AT91C_PIO_PA25 | AT91C_PIO_PA26;
62	pPio->PIO_PDR = AT91C_PIO_PA25 | AT91C_PIO_PA26;
63
64	pPio->PIO_MDDR = ~AT91C_PIO_PA25;
65	pPio->PIO_MDER = AT91C_PIO_PA25;
66
67	pPMC->PMC_PCER = 1u << AT91C_ID_TWI;
68
69	twiPtr->TWI_IDR = 0xffffffffu;
70	twiPtr->TWI_CR = AT91C_TWI_SWRST;
71	twiPtr->TWI_CR = AT91C_TWI_MSEN | AT91C_TWI_SVDIS;
72
73	twiPtr->TWI_CWGR = SET_TWI_CLOCK;
74}
75
76
77/*
78 * .KB_C_FN_DEFINITION_START
79 * void ReadEEPROM(unsigned ee_addr, char *data_addr, unsigned size)
80 *  This global function reads data from the eeprom at ee_addr storing data
81 * to data_addr for size bytes.  Assume the TWI has been initialized.
82 * This function does not utilize the page read mode to simplify the code.
83 * .KB_C_FN_DEFINITION_END
84 */
85int
86ReadEEPROM(unsigned ee_off, unsigned char *data_addr, unsigned size)
87{
88	const AT91PS_TWI 	twiPtr = AT91C_BASE_TWI;
89	unsigned int status;
90	unsigned int count;
91
92	status = twiPtr->TWI_SR;
93	status = twiPtr->TWI_RHR;
94
95	// Set the TWI Master Mode Register
96	twiPtr->TWI_MMR = (TWSI_EEPROM_ADDRESS << 16) |
97	    AT91C_TWI_IADRSZ_2_BYTE | AT91C_TWI_MREAD;
98
99	// Set TWI Internal Address Register
100	twiPtr->TWI_IADR = ee_off;
101
102	// Start transfer
103	twiPtr->TWI_CR = AT91C_TWI_START;
104
105	status = twiPtr->TWI_SR;
106
107	while (size-- > 1){
108		// Wait RHR Holding register is full
109		count = 1000000;
110		while (!(twiPtr->TWI_SR & AT91C_TWI_RXRDY) && --count > 0)
111			continue;
112		if (count <= 0)
113			return -1;
114
115		// Read byte
116		*(data_addr++) = twiPtr->TWI_RHR;
117	}
118
119	twiPtr->TWI_CR = AT91C_TWI_STOP;
120
121	status = twiPtr->TWI_SR;
122
123	// Wait transfer is finished
124	while (!(twiPtr->TWI_SR & AT91C_TWI_TXCOMP))
125		continue;
126
127	// Read last byte
128	*data_addr = twiPtr->TWI_RHR;
129	return 0;
130}
131
132
133/*
134 * .KB_C_FN_DEFINITION_START
135 * void WriteEEPROM(unsigned ee_off, char *data_addr, unsigned size)
136 *  This global function writes data to the eeprom at ee_off using data
137 * from data_addr for size bytes.  Assume the TWI has been initialized.
138 * This function does not utilize the page write mode as the write time is
139 * much greater than the time required to access the device for byte-write
140 * functionality.  This allows the function to be much simpler.
141 * .KB_C_FN_DEFINITION_END
142 */
143void
144WriteEEPROM(unsigned ee_off, char *data_addr, unsigned size)
145{
146	const AT91PS_TWI 	twiPtr = AT91C_BASE_TWI;
147	unsigned		status;
148	unsigned char		test_data;
149
150	while (size--) {
151		if (!(ee_off & 0x3f))
152			putchar('.');
153
154		// Set the TWI Master Mode Register
155		twiPtr->TWI_MMR = ((TWSI_EEPROM_ADDRESS << 16) |
156		    AT91C_TWI_IADRSZ_2_BYTE) & ~AT91C_TWI_MREAD;
157
158		// Set TWI Internal Address Register
159		twiPtr->TWI_IADR = ee_off++;
160
161		status = twiPtr->TWI_SR;
162
163		twiPtr->TWI_THR = *(data_addr++);
164
165		twiPtr->TWI_CR = AT91C_TWI_START;
166
167		// Wait transfer is finished
168		while (!(twiPtr->TWI_SR & AT91C_TWI_TXRDY))
169			continue;
170
171		twiPtr->TWI_CR = AT91C_TWI_STOP;
172
173		status = twiPtr->TWI_SR;
174
175		// Wait transfer is finished
176		while (!(twiPtr->TWI_SR & AT91C_TWI_TXCOMP))
177			continue;
178
179		// wait for write operation to complete
180		ReadEEPROM(ee_off, &test_data, 1);
181	}
182
183	putchar('\r');
184	putchar('\n');
185}
186