| Guennadi Liakhovetski | 6be2b09 | 2009-02-06 10:37:41 +0100 | [diff] [blame] | 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 | } |