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689551c5 GL |
1 | /* |
2 | * Copyright (C) 2009 | |
3 | * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de> | |
4 | * | |
5 | * See file CREDITS for list of people who contributed to this | |
6 | * project. | |
7 | * | |
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. | |
12 | * | |
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. | |
17 | * | |
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, | |
21 | * MA 02111-1307 USA | |
22 | */ | |
23 | #include <common.h> | |
24 | #include <spi.h> | |
25 | #include <s6e63d6.h> | |
26 | ||
27 | /* | |
28 | * Each transfer is performed as: | |
29 | * 1. chip-select active | |
30 | * 2. send 8-bit start code | |
31 | * 3. send 16-bit data | |
32 | * 4. chip-select inactive | |
33 | */ | |
34 | static int send_word(struct s6e63d6 *data, u8 rs, u16 word) | |
35 | { | |
36 | /* | |
37 | * The start byte looks like (binary): | |
38 | * 01110<ID><RS><R/W> | |
39 | * RS is 0 for index or 1 for data, and R/W is 0 for write. | |
40 | */ | |
41 | u32 buf8 = 0x70 | data->id | (rs & 2); | |
42 | u32 buf16 = cpu_to_le16(word); | |
43 | u32 buf_in; | |
44 | int err; | |
45 | ||
46 | err = spi_xfer(data->slave, 8, &buf8, &buf_in, SPI_XFER_BEGIN); | |
47 | if (err) | |
48 | return err; | |
49 | ||
50 | return spi_xfer(data->slave, 16, &buf16, &buf_in, SPI_XFER_END); | |
51 | } | |
52 | ||
53 | /* Index and param differ in Register Select bit */ | |
54 | int s6e63d6_index(struct s6e63d6 *data, u8 idx) | |
55 | { | |
56 | return send_word(data, 0, idx); | |
57 | } | |
58 | ||
59 | int s6e63d6_param(struct s6e63d6 *data, u16 param) | |
60 | { | |
61 | return send_word(data, 2, param); | |
62 | } | |
63 | ||
64 | int s6e63d6_init(struct s6e63d6 *data) | |
65 | { | |
66 | if (data->id != 0 && data->id != 4) { | |
67 | printf("s6e63d6: invalid ID %u\n", data->id); | |
68 | return 1; | |
69 | } | |
70 | ||
71 | data->slave = spi_setup_slave(data->bus, data->cs, 100000, SPI_MODE_3); | |
72 | if (!data->slave) | |
73 | return 1; | |
74 | ||
75 | return 0; | |
76 | } |