mirror of
https://github.com/AsahiLinux/u-boot
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77 lines
2 KiB
C
77 lines
2 KiB
C
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/*
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* Copyright (C) 2009
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* Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#include <common.h>
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#include <spi.h>
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#include <s6e63d6.h>
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/*
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* Each transfer is performed as:
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* 1. chip-select active
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* 2. send 8-bit start code
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* 3. send 16-bit data
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* 4. chip-select inactive
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*/
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static int send_word(struct s6e63d6 *data, u8 rs, u16 word)
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{
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/*
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* The start byte looks like (binary):
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* 01110<ID><RS><R/W>
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* RS is 0 for index or 1 for data, and R/W is 0 for write.
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*/
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u32 buf8 = 0x70 | data->id | (rs & 2);
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u32 buf16 = cpu_to_le16(word);
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u32 buf_in;
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int err;
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err = spi_xfer(data->slave, 8, &buf8, &buf_in, SPI_XFER_BEGIN);
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if (err)
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return err;
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return spi_xfer(data->slave, 16, &buf16, &buf_in, SPI_XFER_END);
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}
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/* Index and param differ in Register Select bit */
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int s6e63d6_index(struct s6e63d6 *data, u8 idx)
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{
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return send_word(data, 0, idx);
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}
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int s6e63d6_param(struct s6e63d6 *data, u16 param)
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{
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return send_word(data, 2, param);
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}
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int s6e63d6_init(struct s6e63d6 *data)
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{
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if (data->id != 0 && data->id != 4) {
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printf("s6e63d6: invalid ID %u\n", data->id);
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return 1;
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}
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data->slave = spi_setup_slave(data->bus, data->cs, 100000, SPI_MODE_3);
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if (!data->slave)
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return 1;
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return 0;
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}
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