| /* |
| * Copyright (c) 2012, The Linux Foundation. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include <sys/types.h> |
| #include <platform/timer.h> |
| #include <dev/gpio.h> |
| |
| void spi_bit_bang_write(uint8_t spi_sclk, uint8_t spi_mosi, uint8_t dc, uint8_t data) |
| { |
| uint8_t bit; |
| uint8_t bnum; |
| |
| gpio_set(spi_sclk, 0); /* clk low */ |
| /* dc: 0 for command, 1 for parameter */ |
| gpio_set(spi_mosi, dc); |
| udelay(1); /* at least 20 ns */ |
| gpio_set(spi_sclk, 1); /* clk high */ |
| udelay(1); /* at least 20 ns */ |
| bnum = 8; /* 8 data bits */ |
| bit = 0x80; |
| while(bnum){ |
| gpio_set(spi_sclk, 0); /* clk low */ |
| if (data & bit) |
| gpio_set(spi_mosi, 1); |
| else |
| gpio_set(spi_mosi, 0); |
| udelay(1); |
| gpio_set(spi_sclk, 1); /* clk high */ |
| udelay(1); |
| bit >>= 1; |
| bnum--; |
| } |
| } |