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git.ipfire.org Git - people/ms/u-boot.git/blob - arch/powerpc/cpu/mpc512x/i2c.c
2 * (C) Copyright 2003 - 2009
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 * See file CREDITS for list of people who contributed to this
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23 * Based on the MPC5xxx code.
29 DECLARE_GLOBAL_DATA_PTR
;
31 #ifdef CONFIG_HARD_I2C
35 /* by default set I2C bus 0 active */
36 static unsigned int bus_num
__attribute__ ((section (".data"))) = 0;
38 #define I2C_TIMEOUT 100
41 struct mpc512x_i2c_tap
{
46 static int mpc_reg_in(volatile u32
*reg
);
47 static void mpc_reg_out(volatile u32
*reg
, int val
, int mask
);
48 static int wait_for_bb(void);
49 static int wait_for_pin(int *status
);
50 static int do_address(uchar chip
, char rdwr_flag
);
51 static int send_bytes(uchar chip
, char *buf
, int len
);
52 static int receive_bytes(uchar chip
, char *buf
, int len
);
53 static int mpc_get_fdr(int);
55 static int mpc_reg_in (volatile u32
*reg
)
57 int ret
= in_be32(reg
) >> 24;
62 static void mpc_reg_out (volatile u32
*reg
, int val
, int mask
)
65 out_be32(reg
, val
<< 24);
67 clrsetbits_be32(reg
, mask
<< 24, (val
& mask
) << 24);
71 static int wait_for_bb (void)
73 volatile immap_t
*im
= (immap_t
*) CONFIG_SYS_IMMR
;
74 volatile i2c512x_dev_t
*regs
= &im
->i2c
.dev
[bus_num
];
75 int timeout
= I2C_TIMEOUT
;
78 status
= mpc_reg_in (®s
->msr
);
80 while (timeout
-- && (status
& I2C_BB
)) {
82 mpc_reg_out (®s
->mcr
, I2C_STA
, I2C_STA
);
83 temp
= mpc_reg_in (®s
->mdr
);
84 mpc_reg_out (®s
->mcr
, 0, I2C_STA
);
85 mpc_reg_out (®s
->mcr
, 0, 0);
86 mpc_reg_out (®s
->mcr
, I2C_EN
, 0);
89 status
= mpc_reg_in (®s
->msr
);
92 return (status
& I2C_BB
);
95 static int wait_for_pin (int *status
)
97 volatile immap_t
*im
= (immap_t
*) CONFIG_SYS_IMMR
;
98 volatile i2c512x_dev_t
*regs
= &im
->i2c
.dev
[bus_num
];
99 int timeout
= I2C_TIMEOUT
;
101 *status
= mpc_reg_in (®s
->msr
);
103 while (timeout
-- && !(*status
& I2C_IF
)) {
105 *status
= mpc_reg_in (®s
->msr
);
108 if (!(*status
& I2C_IF
)) {
112 mpc_reg_out (®s
->msr
, 0, I2C_IF
);
117 static int do_address (uchar chip
, char rdwr_flag
)
119 volatile immap_t
*im
= (immap_t
*) CONFIG_SYS_IMMR
;
120 volatile i2c512x_dev_t
*regs
= &im
->i2c
.dev
[bus_num
];
129 mpc_reg_out (®s
->mcr
, I2C_TX
, I2C_TX
);
130 mpc_reg_out (®s
->mdr
, chip
, 0);
132 if (wait_for_pin (&status
)) {
136 if (status
& I2C_RXAK
) {
143 static int send_bytes (uchar chip
, char *buf
, int len
)
145 volatile immap_t
*im
= (immap_t
*) CONFIG_SYS_IMMR
;
146 volatile i2c512x_dev_t
*regs
= &im
->i2c
.dev
[bus_num
];
150 for (wrcount
= 0; wrcount
< len
; ++wrcount
) {
152 mpc_reg_out (®s
->mdr
, buf
[wrcount
], 0);
154 if (wait_for_pin (&status
)) {
158 if (status
& I2C_RXAK
) {
164 return !(wrcount
== len
);
167 static int receive_bytes (uchar chip
, char *buf
, int len
)
169 volatile immap_t
*im
= (immap_t
*) CONFIG_SYS_IMMR
;
170 volatile i2c512x_dev_t
*regs
= &im
->i2c
.dev
[bus_num
];
176 mpc_reg_out (®s
->mcr
, 0, I2C_TX
);
178 for (i
= 0; i
< len
; ++i
) {
179 buf
[rdcount
] = mpc_reg_in (®s
->mdr
);
187 if (wait_for_pin (&status
)) {
192 mpc_reg_out (®s
->mcr
, I2C_TXAK
, I2C_TXAK
);
193 buf
[rdcount
++] = mpc_reg_in (®s
->mdr
);
195 if (wait_for_pin (&status
)) {
199 mpc_reg_out (®s
->mcr
, 0, I2C_TXAK
);
204 /**************** I2C API ****************/
206 void i2c_init (int speed
, int saddr
)
208 volatile immap_t
*im
= (immap_t
*) CONFIG_SYS_IMMR
;
211 for (i
= 0; i
< I2C_BUS_CNT
; i
++){
212 volatile i2c512x_dev_t
*regs
= &im
->i2c
.dev
[i
];
214 mpc_reg_out (®s
->mcr
, 0, 0);
217 mpc_reg_out (®s
->mfdr
, mpc_get_fdr (speed
), 0);
218 mpc_reg_out (®s
->madr
, saddr
<< 1, 0);
221 mpc_reg_out (®s
->mcr
, I2C_EN
, I2C_INIT_MASK
);
222 mpc_reg_out (®s
->msr
, 0, I2C_IF
);
225 /* Disable interrupts */
226 out_be32(&im
->i2c
.icr
, 0);
228 /* Turn off filters */
229 out_be32(&im
->i2c
.mifr
, 0);
232 static int mpc_get_fdr (int speed
)
237 ulong best_speed
= 0;
240 ulong bestmatch
= 0xffffffffUL
;
241 int best_i
= 0, best_j
= 0, i
, j
;
242 int SCL_Tap
[] = { 9, 10, 12, 15, 5, 6, 7, 8};
243 struct mpc512x_i2c_tap scltap
[] = {
255 for (i
= 7; i
>= 0; i
--) {
256 for (j
= 7; j
>= 0; j
--) {
257 scl
= 2 * (scltap
[j
].scl2tap
+
258 (SCL_Tap
[i
] - 1) * scltap
[j
].tap2tap
260 if (ips
<= speed
*scl
) {
261 if ((speed
*scl
- ips
) < bestmatch
) {
262 bestmatch
= speed
*scl
- ips
;
265 best_speed
= ips
/scl
;
270 divider
= (best_i
& 3) | ((best_i
& 4) << 3) | (best_j
<< 2);
271 if (gd
->flags
& GD_FLG_RELOC
) {
274 debug("%ld kHz, \n", best_speed
/ 1000);
282 int i2c_probe (uchar chip
)
284 volatile immap_t
*im
= (immap_t
*) CONFIG_SYS_IMMR
;
285 volatile i2c512x_dev_t
*regs
= &im
->i2c
.dev
[bus_num
];
288 for (i
= 0; i
< I2C_RETRIES
; i
++) {
289 mpc_reg_out (®s
->mcr
, I2C_STA
, I2C_STA
);
291 if (! do_address (chip
, 0)) {
292 mpc_reg_out (®s
->mcr
, 0, I2C_STA
);
297 mpc_reg_out (®s
->mcr
, 0, I2C_STA
);
301 return (i
== I2C_RETRIES
);
304 int i2c_read (uchar chip
, uint addr
, int alen
, uchar
*buf
, int len
)
306 volatile immap_t
*im
= (immap_t
*) CONFIG_SYS_IMMR
;
307 volatile i2c512x_dev_t
*regs
= &im
->i2c
.dev
[bus_num
];
311 xaddr
[0] = (addr
>> 24) & 0xFF;
312 xaddr
[1] = (addr
>> 16) & 0xFF;
313 xaddr
[2] = (addr
>> 8) & 0xFF;
314 xaddr
[3] = addr
& 0xFF;
316 if (wait_for_bb ()) {
317 printf ("i2c_read: bus is busy\n");
321 mpc_reg_out (®s
->mcr
, I2C_STA
, I2C_STA
);
322 if (do_address (chip
, 0)) {
323 printf ("i2c_read: failed to address chip\n");
327 if (send_bytes (chip
, &xaddr
[4-alen
], alen
)) {
328 printf ("i2c_read: send_bytes failed\n");
332 mpc_reg_out (®s
->mcr
, I2C_RSTA
, I2C_RSTA
);
333 if (do_address (chip
, 1)) {
334 printf ("i2c_read: failed to address chip\n");
338 if (receive_bytes (chip
, (char *)buf
, len
)) {
339 printf ("i2c_read: receive_bytes failed\n");
345 mpc_reg_out (®s
->mcr
, 0, I2C_STA
);
349 int i2c_write (uchar chip
, uint addr
, int alen
, uchar
*buf
, int len
)
351 volatile immap_t
*im
= (immap_t
*) CONFIG_SYS_IMMR
;
352 volatile i2c512x_dev_t
*regs
= &im
->i2c
.dev
[bus_num
];
356 xaddr
[0] = (addr
>> 24) & 0xFF;
357 xaddr
[1] = (addr
>> 16) & 0xFF;
358 xaddr
[2] = (addr
>> 8) & 0xFF;
359 xaddr
[3] = addr
& 0xFF;
361 if (wait_for_bb ()) {
362 printf ("i2c_write: bus is busy\n");
366 mpc_reg_out (®s
->mcr
, I2C_STA
, I2C_STA
);
367 if (do_address (chip
, 0)) {
368 printf ("i2c_write: failed to address chip\n");
372 if (send_bytes (chip
, &xaddr
[4-alen
], alen
)) {
373 printf ("i2c_write: send_bytes failed\n");
377 if (send_bytes (chip
, (char *)buf
, len
)) {
378 printf ("i2c_write: send_bytes failed\n");
384 mpc_reg_out (®s
->mcr
, 0, I2C_STA
);
388 int i2c_set_bus_num (unsigned int bus
)
390 if (bus
>= I2C_BUS_CNT
) {
398 unsigned int i2c_get_bus_num (void)
403 #endif /* CONFIG_HARD_I2C */