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Guennadi Liakhovetski689551c2009-02-06 10:37:41 +01001/*
2 * Copyright (C) 2009
3 * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
4 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02005 * SPDX-License-Identifier: GPL-2.0+
Guennadi Liakhovetski689551c2009-02-06 10:37:41 +01006 */
7#include <common.h>
8#include <spi.h>
9#include <s6e63d6.h>
10
11/*
12 * Each transfer is performed as:
13 * 1. chip-select active
14 * 2. send 8-bit start code
15 * 3. send 16-bit data
16 * 4. chip-select inactive
17 */
18static int send_word(struct s6e63d6 *data, u8 rs, u16 word)
19{
20 /*
21 * The start byte looks like (binary):
22 * 01110<ID><RS><R/W>
23 * RS is 0 for index or 1 for data, and R/W is 0 for write.
24 */
25 u32 buf8 = 0x70 | data->id | (rs & 2);
26 u32 buf16 = cpu_to_le16(word);
27 u32 buf_in;
28 int err;
29
30 err = spi_xfer(data->slave, 8, &buf8, &buf_in, SPI_XFER_BEGIN);
31 if (err)
32 return err;
33
34 return spi_xfer(data->slave, 16, &buf16, &buf_in, SPI_XFER_END);
35}
36
37/* Index and param differ in Register Select bit */
38int s6e63d6_index(struct s6e63d6 *data, u8 idx)
39{
40 return send_word(data, 0, idx);
41}
42
43int s6e63d6_param(struct s6e63d6 *data, u16 param)
44{
45 return send_word(data, 2, param);
46}
47
48int s6e63d6_init(struct s6e63d6 *data)
49{
50 if (data->id != 0 && data->id != 4) {
51 printf("s6e63d6: invalid ID %u\n", data->id);
52 return 1;
53 }
54
55 data->slave = spi_setup_slave(data->bus, data->cs, 100000, SPI_MODE_3);
56 if (!data->slave)
57 return 1;
58
59 return 0;
60}