git.sur5r.net Git - u-boot/blob - drivers/i2c/pca9564_i2c.c

   1 /*
   2  * File:         drivers/i2c/pca9564.c
   3  * Based on:     drivers/i2c/s3c44b0_i2c.c
   4  * Author:
   5  *
   6  * Created:      2009-06-23
   7  * Description:  PCA9564 i2c bridge driver
   8  *
   9  * Modified:
  10  *               Copyright 2009 CJSC "NII STT", http://www.niistt.ru/
  11  *
  12  * Bugs:
  13  *
  14  * SPDX-License-Identifier:     GPL-2.0+
  15  *
  16  * NOTE: This driver should be converted to driver model before June 2017.
  17  * Please see doc/driver-model/i2c-howto.txt for instructions.
  18  */
  19
  20 #include <common.h>
  21 #include <i2c.h>
  22 #include <pca9564.h>
  23 #include <asm/io.h>
  24
  25 #define PCA_STA                 (CONFIG_PCA9564_BASE + 0)
  26 #define PCA_TO                  (CONFIG_PCA9564_BASE + 0)
  27 #define PCA_DAT                 (CONFIG_PCA9564_BASE + (1 << 2))
  28 #define PCA_ADR                 (CONFIG_PCA9564_BASE + (2 << 2))
  29 #define PCA_CON                 (CONFIG_PCA9564_BASE + (3 << 2))
  30
  31 static unsigned char pca_read_reg(unsigned int reg)
  32 {
  33         return readb((void *)reg);
  34 }
  35
  36 static void pca_write_reg(unsigned int reg, unsigned char value)
  37 {
  38         writeb(value, (void *)reg);
  39 }
  40
  41 static int pca_wait_busy(void)
  42 {
  43         unsigned int timeout = 10000;
  44
  45         while (!(pca_read_reg(PCA_CON) & PCA_CON_SI) && --timeout)
  46                 udelay(1);
  47
  48         if (timeout == 0)
  49                 debug("I2C timeout!\n");
  50
  51         debug("CON = 0x%02x, STA = 0x%02x\n", pca_read_reg(PCA_CON),
  52                pca_read_reg(PCA_STA));
  53
  54         return timeout ? 0 : 1;
  55 }
  56
  57 /*=====================================================================*/
  58 /*                         Public Functions                            */
  59 /*=====================================================================*/
  60
  61 /*-----------------------------------------------------------------------
  62  * Initialization
  63  */
  64 void i2c_init(int speed, int slaveaddr)
  65 {
  66         pca_write_reg(PCA_CON, PCA_CON_ENSIO | speed);
  67 }
  68
  69 /*
  70  * Probe the given I2C chip address.  Returns 0 if a chip responded,
  71  * not 0 on failure.
  72  */
  73
  74 int i2c_probe(uchar chip)
  75 {
  76         unsigned char res;
  77
  78         pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO);
  79         pca_wait_busy();
  80
  81         pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO);
  82
  83         pca_write_reg(PCA_DAT, (chip << 1) | 1);
  84         res = pca_wait_busy();
  85
  86         if ((res == 0) && (pca_read_reg(PCA_STA) == 0x48))
  87                 res = 1;
  88
  89         pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO);
  90
  91         return res;
  92 }
  93
  94 /*
  95  * Read/Write interface:
  96  *   chip:    I2C chip address, range 0..127
  97  *   addr:    Memory (register) address within the chip
  98  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
  99  *              memories, 0 for register type devices with only one
 100  *              register)
 101  *   buffer:  Where to read/write the data
 102  *   len:     How many bytes to read/write
 103  *
 104  *   Returns: 0 on success, not 0 on failure
 105  */
 106 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 107 {
 108         int i;
 109
 110         pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
 111         pca_wait_busy();
 112
 113         pca_write_reg(PCA_CON, PCA_CON_ENSIO);
 114
 115         pca_write_reg(PCA_DAT, (chip << 1));
 116         pca_wait_busy();
 117         pca_write_reg(PCA_CON, PCA_CON_ENSIO);
 118
 119         if (alen > 0) {
 120                 pca_write_reg(PCA_DAT, addr);
 121                 pca_wait_busy();
 122                 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
 123         }
 124
 125         pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO);
 126
 127         udelay(500);
 128
 129         pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
 130         pca_wait_busy();
 131         pca_write_reg(PCA_CON, PCA_CON_ENSIO);
 132
 133         pca_write_reg(PCA_DAT, (chip << 1) | 1);
 134         pca_wait_busy();
 135
 136         for (i = 0; i < len; ++i) {
 137                 if (i == len - 1)
 138                         pca_write_reg(PCA_CON, PCA_CON_ENSIO);
 139                 else
 140                         pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_AA);
 141
 142                 pca_wait_busy();
 143                 buffer[i] = pca_read_reg(PCA_DAT);
 144
 145         }
 146
 147         pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO);
 148
 149         return 0;
 150 }
 151
 152 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 153 {
 154         int i;
 155
 156         pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
 157         pca_wait_busy();
 158         pca_write_reg(PCA_CON, PCA_CON_ENSIO);
 159
 160         pca_write_reg(PCA_DAT, chip << 1);
 161         pca_wait_busy();
 162         pca_write_reg(PCA_CON, PCA_CON_ENSIO);
 163
 164         if (alen > 0) {
 165                 pca_write_reg(PCA_DAT, addr);
 166                 pca_wait_busy();
 167                 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
 168         }
 169
 170         for (i = 0; i < len; ++i) {
 171                 pca_write_reg(PCA_DAT, buffer[i]);
 172                 pca_wait_busy();
 173                 pca_write_reg(PCA_CON, PCA_CON_ENSIO);
 174         }
 175
 176         pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO);
 177
 178         return 0;
 179 }