s6e63d6.c
1.25 KB
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/*
* Copyright (C) 2009
* Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <spi.h>
#include <s6e63d6.h>
/*
* Each transfer is performed as:
* 1. chip-select active
* 2. send 8-bit start code
* 3. send 16-bit data
* 4. chip-select inactive
*/
static int send_word(struct s6e63d6 *data, u8 rs, u16 word)
{
/*
* The start byte looks like (binary):
* 01110<ID><RS><R/W>
* RS is 0 for index or 1 for data, and R/W is 0 for write.
*/
u32 buf8 = 0x70 | data->id | (rs & 2);
u32 buf16 = cpu_to_le16(word);
u32 buf_in;
int err;
err = spi_xfer(data->slave, 8, &buf8, &buf_in, SPI_XFER_BEGIN);
if (err)
return err;
return spi_xfer(data->slave, 16, &buf16, &buf_in, SPI_XFER_END);
}
/* Index and param differ in Register Select bit */
int s6e63d6_index(struct s6e63d6 *data, u8 idx)
{
return send_word(data, 0, idx);
}
int s6e63d6_param(struct s6e63d6 *data, u16 param)
{
return send_word(data, 2, param);
}
int s6e63d6_init(struct s6e63d6 *data)
{
if (data->id != 0 && data->id != 4) {
printf("s6e63d6: invalid ID %u\n", data->id);
return 1;
}
data->slave = spi_setup_slave(data->bus, data->cs, 100000, SPI_MODE_3);
if (!data->slave)
return 1;
return 0;
}