Blame view
drivers/i2c/pca9564_i2c.c
3.89 KB
08ea550ee
|
1 2 3 4 5 6 7 8 9 10 11 12 13 |
/* * File: drivers/i2c/pca9564.c * Based on: drivers/i2c/s3c44b0_i2c.c * Author: * * Created: 2009-06-23 * Description: PCA9564 i2c bridge driver * * Modified: * Copyright 2009 CJSC "NII STT", http://www.niistt.ru/ * * Bugs: * |
1a4596601
|
14 |
* SPDX-License-Identifier: GPL-2.0+ |
08ea550ee
|
15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 |
*/ #include <common.h> #include <i2c.h> #include <pca9564.h> #include <asm/io.h> #define PCA_STA (CONFIG_PCA9564_BASE + 0) #define PCA_TO (CONFIG_PCA9564_BASE + 0) #define PCA_DAT (CONFIG_PCA9564_BASE + (1 << 2)) #define PCA_ADR (CONFIG_PCA9564_BASE + (2 << 2)) #define PCA_CON (CONFIG_PCA9564_BASE + (3 << 2)) static unsigned char pca_read_reg(unsigned int reg) { return readb((void *)reg); } static void pca_write_reg(unsigned int reg, unsigned char value) { writeb(value, (void *)reg); } static int pca_wait_busy(void) { unsigned int timeout = 10000; while (!(pca_read_reg(PCA_CON) & PCA_CON_SI) && --timeout) udelay(1); if (timeout == 0) debug("I2C timeout! "); debug("CON = 0x%02x, STA = 0x%02x ", pca_read_reg(PCA_CON), pca_read_reg(PCA_STA)); return timeout ? 0 : 1; } /*=====================================================================*/ /* Public Functions */ /*=====================================================================*/ /*----------------------------------------------------------------------- * Initialization */ void i2c_init(int speed, int slaveaddr) { pca_write_reg(PCA_CON, PCA_CON_ENSIO | speed); } /* * Probe the given I2C chip address. Returns 0 if a chip responded, * not 0 on failure. */ int i2c_probe(uchar chip) { unsigned char res; pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO); pca_wait_busy(); pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO); pca_write_reg(PCA_DAT, (chip << 1) | 1); res = pca_wait_busy(); if ((res == 0) && (pca_read_reg(PCA_STA) == 0x48)) res = 1; pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO); return res; } /* * Read/Write interface: * chip: I2C chip address, range 0..127 * addr: Memory (register) address within the chip * alen: Number of bytes to use for addr (typically 1, 2 for larger * memories, 0 for register type devices with only one * register) * buffer: Where to read/write the data * len: How many bytes to read/write * * Returns: 0 on success, not 0 on failure */ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) { int i; pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA); pca_wait_busy(); pca_write_reg(PCA_CON, PCA_CON_ENSIO); pca_write_reg(PCA_DAT, (chip << 1)); pca_wait_busy(); pca_write_reg(PCA_CON, PCA_CON_ENSIO); if (alen > 0) { pca_write_reg(PCA_DAT, addr); pca_wait_busy(); pca_write_reg(PCA_CON, PCA_CON_ENSIO); } pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO); udelay(500); pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA); pca_wait_busy(); pca_write_reg(PCA_CON, PCA_CON_ENSIO); pca_write_reg(PCA_DAT, (chip << 1) | 1); pca_wait_busy(); for (i = 0; i < len; ++i) { if (i == len - 1) pca_write_reg(PCA_CON, PCA_CON_ENSIO); else pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_AA); pca_wait_busy(); buffer[i] = pca_read_reg(PCA_DAT); } pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO); return 0; } int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) { int i; pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA); pca_wait_busy(); pca_write_reg(PCA_CON, PCA_CON_ENSIO); pca_write_reg(PCA_DAT, chip << 1); pca_wait_busy(); pca_write_reg(PCA_CON, PCA_CON_ENSIO); if (alen > 0) { pca_write_reg(PCA_DAT, addr); pca_wait_busy(); pca_write_reg(PCA_CON, PCA_CON_ENSIO); } for (i = 0; i < len; ++i) { pca_write_reg(PCA_DAT, buffer[i]); pca_wait_busy(); pca_write_reg(PCA_CON, PCA_CON_ENSIO); } pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO); return 0; } |