/* * Copyright (C) 2009 * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de> * * See file CREDITS for list of people who contributed to this * project. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, * MA 02111-1307 USA */ #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; }