drivers/video/s5p-spi.c

   1 #include <common.h>
   2 #include <asm/arch/gpio.h>
   3 #include "s5p-spi.h"
   4
   5
   6 static void cs_low(struct spi_platform_data *spi)
   7 {
   8         gpio_set_value(spi->cs_bank, spi->cs_num, 0);
   9 }
  10
  11 static void cs_high(struct spi_platform_data *spi)
  12 {
  13         gpio_set_value(spi->cs_bank, spi->cs_num, 1);
  14 }
  15
  16 static void clk_low(struct spi_platform_data *spi)
  17 {
  18         gpio_set_value(spi->clk_bank, spi->clk_num, 0);
  19 }
  20
  21 static void clk_high(struct spi_platform_data *spi)
  22 {
  23         gpio_set_value(spi->clk_bank, spi->clk_num, 1);
  24 }
  25
  26 static void si_low(struct spi_platform_data *spi)
  27 {
  28         gpio_set_value(spi->si_bank, spi->si_num, 0);
  29 }
  30
  31 static void si_high(struct spi_platform_data *spi)
  32 {
  33         gpio_set_value(spi->si_bank, spi->si_num, 1);
  34 }
  35
  36 /*
  37 static char so_read(struct spi_platform_data *spi)
  38 {
  39         return gpio_get_value(spi->so_bank, spi->so_num);
  40 }
  41 */
  42
  43 void spi_write_byte(struct spi_platform_data *spi, unsigned char address, unsigned char command)
  44 {
  45         int     j;
  46         unsigned short data;
  47         unsigned char DELAY = 1;
  48
  49         data = (address << 8) + command;
  50
  51         cs_high(spi);
  52         si_high(spi);
  53         clk_high(spi);
  54         udelay(DELAY);
  55
  56         cs_low(spi);
  57         udelay(DELAY);
  58
  59         for (j = PACKET_LEN; j >= 0; j--) {
  60                 clk_low(spi);
  61
  62                 /* data high or low */
  63                 if ((data >> j) & 0x1)
  64                         si_high(spi);
  65                 else
  66                         si_low(spi);
  67
  68                 udelay(DELAY);
  69
  70                 clk_high(spi);
  71                 udelay(DELAY);
  72         }
  73
  74         cs_high(spi);
  75         udelay(DELAY);
  76 }
  77
  78 #ifdef UNUSED_FUNCTIONS
  79 unsigned char spi_read_byte(struct spi_platform_data *spi, unsigned char select, unsigned char address)
  80 {
  81         int     j;
  82         static unsigned int first = 1;
  83         unsigned char DELAY = 1;
  84         unsigned short data = 0;
  85         char command = 0;
  86
  87         data = (select << 8) + address;
  88
  89         cs_high(spi);
  90         si_high(spi);
  91         clk_high(spi);
  92         udelay(DELAY);
  93
  94         clk_low(spi);
  95         udelay(DELAY);
  96
  97         for (j = PACKET_LEN + 8; j >= 0; j--) {
  98
  99                 if (j > 7) {
 100                         clk_low(spi);
 101
 102                         /* data high or low */
 103                         if ((data >> (j - 8)) & 0x1)
 104                                 si_high(spi);
 105                         else
 106                                 si_low(spi);
 107
 108                         udelay(DELAY);
 109                         clk_high(spi);
 110                 } else {
 111                         if (first) {
 112                                 gpio_cfg_pin(spi->so_bank, spi->so_num, GPIO_INPUT);
 113                                 first = 0;
 114                         }
 115
 116                         clk_low(spi);
 117
 118                         if (so_read(spi) & 0x1)
 119                                 command |= 1 << j;
 120                         else
 121                                 command |= 0 << j;
 122
 123                         udelay(DELAY);
 124                         clk_high(spi);
 125                 }
 126
 127                 udelay(DELAY);
 128         }
 129
 130         cs_high(spi);
 131         udelay(DELAY);
 132
 133         gpio_cfg_pin(spi->so_bank, spi->so_num, GPIO_OUTPUT);
 134
 135         return command;
 136 }
 137 #endif