xref: /openbmc/linux/drivers/atm/nicstarmac.c (revision 1da177e4)
1 /*
2  * this file included by nicstar.c
3  */
4 
5 /*
6  * nicstarmac.c
7  * Read this ForeRunner's MAC address from eprom/eeprom
8  */
9 
10 typedef void __iomem *virt_addr_t;
11 
12 #define CYCLE_DELAY 5
13 
14 /* This was the original definition
15 #define osp_MicroDelay(microsec) \
16     do { int _i = 4*microsec; while (--_i > 0) { __SLOW_DOWN_IO; }} while (0)
17 */
18 #define osp_MicroDelay(microsec) {unsigned long useconds = (microsec); \
19                                   udelay((useconds));}
20 
21 
22 /* The following tables represent the timing diagrams found in
23  * the Data Sheet for the Xicor X25020 EEProm.  The #defines below
24  * represent the bits in the NICStAR's General Purpose register
25  * that must be toggled for the corresponding actions on the EEProm
26  * to occur.
27  */
28 
29 /* Write Data To EEProm from SI line on rising edge of CLK */
30 /* Read Data From EEProm on falling edge of CLK */
31 
32 #define CS_HIGH		0x0002		/* Chip select high */
33 #define CS_LOW		0x0000		/* Chip select low (active low)*/
34 #define CLK_HIGH	0x0004		/* Clock high */
35 #define CLK_LOW		0x0000		/* Clock low  */
36 #define SI_HIGH		0x0001		/* Serial input data high */
37 #define SI_LOW		0x0000		/* Serial input data low */
38 
39 /* Read Status Register = 0000 0101b */
40 #if 0
41 static u_int32_t rdsrtab[] =
42 {
43     CS_HIGH | CLK_HIGH,
44     CS_LOW | CLK_LOW,
45     CLK_HIGH,             /* 0 */
46     CLK_LOW,
47     CLK_HIGH,             /* 0 */
48     CLK_LOW,
49     CLK_HIGH,             /* 0 */
50     CLK_LOW,
51     CLK_HIGH,             /* 0 */
52     CLK_LOW,
53     CLK_HIGH,             /* 0 */
54     CLK_LOW | SI_HIGH,
55     CLK_HIGH | SI_HIGH,   /* 1 */
56     CLK_LOW | SI_LOW,
57     CLK_HIGH,             /* 0 */
58     CLK_LOW | SI_HIGH,
59     CLK_HIGH | SI_HIGH   /* 1 */
60 };
61 #endif  /*  0  */
62 
63 
64 /* Read from EEPROM = 0000 0011b */
65 static u_int32_t readtab[] =
66 {
67     /*
68     CS_HIGH | CLK_HIGH,
69     */
70     CS_LOW | CLK_LOW,
71     CLK_HIGH,             /* 0 */
72     CLK_LOW,
73     CLK_HIGH,             /* 0 */
74     CLK_LOW,
75     CLK_HIGH,             /* 0 */
76     CLK_LOW,
77     CLK_HIGH,             /* 0 */
78     CLK_LOW,
79     CLK_HIGH,             /* 0 */
80     CLK_LOW,
81     CLK_HIGH,             /* 0 */
82     CLK_LOW | SI_HIGH,
83     CLK_HIGH | SI_HIGH,   /* 1 */
84     CLK_LOW | SI_HIGH,
85     CLK_HIGH | SI_HIGH    /* 1 */
86 };
87 
88 
89 /* Clock to read from/write to the eeprom */
90 static u_int32_t clocktab[] =
91 {
92     CLK_LOW,
93     CLK_HIGH,
94     CLK_LOW,
95     CLK_HIGH,
96     CLK_LOW,
97     CLK_HIGH,
98     CLK_LOW,
99     CLK_HIGH,
100     CLK_LOW,
101     CLK_HIGH,
102     CLK_LOW,
103     CLK_HIGH,
104     CLK_LOW,
105     CLK_HIGH,
106     CLK_LOW,
107     CLK_HIGH,
108     CLK_LOW
109 };
110 
111 
112 #define NICSTAR_REG_WRITE(bs, reg, val) \
113 	while ( readl(bs + STAT) & 0x0200 ) ; \
114 	writel((val),(base)+(reg))
115 #define NICSTAR_REG_READ(bs, reg) \
116 	readl((base)+(reg))
117 #define NICSTAR_REG_GENERAL_PURPOSE GP
118 
119 /*
120  * This routine will clock the Read_Status_reg function into the X2520
121  * eeprom, then pull the result from bit 16 of the NicSTaR's General Purpose
122  * register.
123  */
124 #if 0
125 u_int32_t
126 nicstar_read_eprom_status( virt_addr_t base )
127 {
128    u_int32_t	val;
129    u_int32_t	rbyte;
130    int32_t	i, j;
131 
132    /* Send read instruction */
133    val = NICSTAR_REG_READ( base, NICSTAR_REG_GENERAL_PURPOSE ) & 0xFFFFFFF0;
134 
135    for (i=0; i<sizeof rdsrtab/sizeof rdsrtab[0]; i++)
136    {
137 	NICSTAR_REG_WRITE( base, NICSTAR_REG_GENERAL_PURPOSE,
138 		(val | rdsrtab[i]) );
139         osp_MicroDelay( CYCLE_DELAY );
140    }
141 
142    /* Done sending instruction - now pull data off of bit 16, MSB first */
143    /* Data clocked out of eeprom on falling edge of clock */
144 
145    rbyte = 0;
146    for (i=7, j=0; i>=0; i--)
147    {
148 	NICSTAR_REG_WRITE( base, NICSTAR_REG_GENERAL_PURPOSE,
149 		(val | clocktab[j++]) );
150         rbyte |= (((NICSTAR_REG_READ( base, NICSTAR_REG_GENERAL_PURPOSE)
151 			& 0x00010000) >> 16) << i);
152 	NICSTAR_REG_WRITE( base, NICSTAR_REG_GENERAL_PURPOSE,
153 		(val | clocktab[j++]) );
154         osp_MicroDelay( CYCLE_DELAY );
155    }
156    NICSTAR_REG_WRITE( base, NICSTAR_REG_GENERAL_PURPOSE, 2 );
157    osp_MicroDelay( CYCLE_DELAY );
158    return rbyte;
159 }
160 #endif  /*  0  */
161 
162 
163 /*
164  * This routine will clock the Read_data function into the X2520
165  * eeprom, followed by the address to read from, through the NicSTaR's General
166  * Purpose register.
167  */
168 
169 static u_int8_t
170 read_eprom_byte(virt_addr_t base, u_int8_t offset)
171 {
172    u_int32_t val = 0;
173    int i,j=0;
174    u_int8_t tempread = 0;
175 
176    val = NICSTAR_REG_READ( base, NICSTAR_REG_GENERAL_PURPOSE ) & 0xFFFFFFF0;
177 
178    /* Send READ instruction */
179    for (i=0; i<sizeof readtab/sizeof readtab[0]; i++)
180    {
181 	NICSTAR_REG_WRITE( base, NICSTAR_REG_GENERAL_PURPOSE,
182 		(val | readtab[i]) );
183         osp_MicroDelay( CYCLE_DELAY );
184    }
185 
186    /* Next, we need to send the byte address to read from */
187    for (i=7; i>=0; i--)
188    {
189       NICSTAR_REG_WRITE( base, NICSTAR_REG_GENERAL_PURPOSE,
190       		(val | clocktab[j++] | ((offset >> i) & 1) ) );
191       osp_MicroDelay(CYCLE_DELAY);
192       NICSTAR_REG_WRITE( base, NICSTAR_REG_GENERAL_PURPOSE,
193       		(val | clocktab[j++] | ((offset >> i) & 1) ) );
194       osp_MicroDelay( CYCLE_DELAY );
195    }
196 
197    j = 0;
198 
199    /* Now, we can read data from the eeprom by clocking it in */
200    for (i=7; i>=0; i--)
201    {
202       NICSTAR_REG_WRITE( base, NICSTAR_REG_GENERAL_PURPOSE,
203       		(val | clocktab[j++]) );
204       osp_MicroDelay( CYCLE_DELAY );
205       tempread |= (((NICSTAR_REG_READ( base, NICSTAR_REG_GENERAL_PURPOSE )
206 		& 0x00010000) >> 16) << i);
207       NICSTAR_REG_WRITE( base, NICSTAR_REG_GENERAL_PURPOSE,
208       		(val | clocktab[j++]) );
209       osp_MicroDelay( CYCLE_DELAY );
210    }
211 
212    NICSTAR_REG_WRITE( base, NICSTAR_REG_GENERAL_PURPOSE, 2 );
213    osp_MicroDelay( CYCLE_DELAY );
214    return tempread;
215 }
216 
217 
218 static void
219 nicstar_init_eprom( virt_addr_t base )
220 {
221     u_int32_t val;
222 
223     /*
224      * turn chip select off
225      */
226     val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0;
227 
228     NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
229     	(val | CS_HIGH | CLK_HIGH));
230     osp_MicroDelay( CYCLE_DELAY );
231 
232     NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
233     	(val | CS_HIGH | CLK_LOW));
234     osp_MicroDelay( CYCLE_DELAY );
235 
236     NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
237     	(val | CS_HIGH | CLK_HIGH));
238     osp_MicroDelay( CYCLE_DELAY );
239 
240     NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
241     	(val | CS_HIGH | CLK_LOW));
242     osp_MicroDelay( CYCLE_DELAY );
243 }
244 
245 
246 /*
247  * This routine will be the interface to the ReadPromByte function
248  * above.
249  */
250 
251 static void
252 nicstar_read_eprom(
253     virt_addr_t	base,
254     u_int8_t	prom_offset,
255     u_int8_t	*buffer,
256     u_int32_t	nbytes )
257 {
258     u_int		i;
259 
260     for (i=0; i<nbytes; i++)
261     {
262 	buffer[i] = read_eprom_byte( base, prom_offset );
263 	++prom_offset;
264  	osp_MicroDelay( CYCLE_DELAY );
265     }
266 }
267 
268 
269 /*
270 void osp_MicroDelay(int x) {
271 
272 }
273 */
274 
275