i2c_simple.h
1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 3 #ifndef _DEVICE_I2C_SIMPLE_H_ 4 #define _DEVICE_I2C_SIMPLE_H_ 5 6 #include <commonlib/helpers.h> 7 #include <device/i2c.h> 8 #include <stdint.h> 9 10 int platform_i2c_transfer(unsigned int bus, struct i2c_msg *segments, 11 int count); 12 13 #define SOFTWARE_I2C_MAX_BUS 10 /* increase as necessary */ 14 15 struct software_i2c_ops { 16 void (*set_sda)(unsigned int bus, int high); 17 void (*set_scl)(unsigned int bus, int high); 18 int (*get_sda)(unsigned int bus); 19 int (*get_scl)(unsigned int bus); 20 }; 21 22 extern struct software_i2c_ops *software_i2c[]; 23 24 int software_i2c_transfer(unsigned int bus, struct i2c_msg *segments, 25 int count); 26 void software_i2c_wedge_ack(unsigned int bus, u8 slave); 27 void software_i2c_wedge_read(unsigned int bus, u8 slave, u8 reg, int bit_count); 28 void software_i2c_wedge_write(unsigned int bus, u8 slave, u8 reg, 29 int bit_count); 30 31 int i2c_read_field(unsigned int bus, uint8_t slave, uint8_t reg, uint8_t *data, 32 uint8_t mask, uint8_t shift); 33 int i2c_write_field(unsigned int bus, uint8_t slave, uint8_t reg, uint8_t data, 34 uint8_t mask, uint8_t shift); 35 36 /* 37 * software_i2c is supposed to be a debug feature. It's usually not compiled in, 38 * but when it is it can be dynamically enabled at runtime for certain buses. 39 * Need this ugly stub to arbitrate since I2C device drivers hardcode 40 * 'i2c_transfer()' as their entry point. 41 */ 42 static inline int i2c_transfer(unsigned int bus, struct i2c_msg *segments, 43 int count) 44 { 45 if (CONFIG(SOFTWARE_I2C)) 46 if (bus < SOFTWARE_I2C_MAX_BUS && software_i2c[bus]) 47 return software_i2c_transfer(bus, segments, count); 48 49 return platform_i2c_transfer(bus, segments, count); 50 } 51 52 /* 53 * Read a raw chunk of data in one segment and one frame. 54 * 55 * [start][slave addr][r][data][stop] 56 */ 57 static inline int i2c_read_raw(unsigned int bus, uint8_t slave, uint8_t *data, 58 int len) 59 { 60 struct i2c_msg seg = { 61 .flags = I2C_M_RD, .slave = slave, .buf = data, .len = len 62 }; 63 64 return i2c_transfer(bus, &seg, 1); 65 } 66 67 /* 68 * Write a raw chunk of data in one segment and one frame. 69 * 70 * [start][slave addr][w][data][stop] 71 */ 72 static inline int i2c_write_raw(unsigned int bus, uint8_t slave, uint8_t *data, 73 int len) 74 { 75 struct i2c_msg seg = { 76 .flags = 0, .slave = slave, .buf = data, .len = len 77 }; 78 79 return i2c_transfer(bus, &seg, 1); 80 } 81 82 /** 83 * Read multi-bytes with two segments in one frame 84 * 85 * [start][slave addr][w][register addr][start][slave addr][r][data...][stop] 86 */ 87 static inline int i2c_read_bytes(unsigned int bus, uint8_t slave, uint8_t reg, 88 uint8_t *data, int len) 89 { 90 struct i2c_msg seg[2]; 91 92 seg[0].flags = 0; 93 seg[0].slave = slave; 94 seg[0].buf = ® 95 seg[0].len = 1; 96 seg[1].flags = I2C_M_RD; 97 seg[1].slave = slave; 98 seg[1].buf = data; 99 seg[1].len = len; 100 101 return i2c_transfer(bus, seg, ARRAY_SIZE(seg)); 102 } 103 104 /** 105 * Read a byte with two segments in one frame 106 * 107 * [start][slave addr][w][register addr][start][slave addr][r][data][stop] 108 */ 109 static inline int i2c_readb(unsigned int bus, uint8_t slave, uint8_t reg, 110 uint8_t *data) 111 { 112 struct i2c_msg seg[2]; 113 114 seg[0].flags = 0; 115 seg[0].slave = slave; 116 seg[0].buf = ® 117 seg[0].len = 1; 118 seg[1].flags = I2C_M_RD; 119 seg[1].slave = slave; 120 seg[1].buf = data; 121 seg[1].len = 1; 122 123 return i2c_transfer(bus, seg, ARRAY_SIZE(seg)); 124 } 125 126 /** 127 * Write a byte with one segment in one frame. 128 * 129 * [start][slave addr][w][register addr][data][stop] 130 */ 131 static inline int i2c_writeb(unsigned int bus, uint8_t slave, uint8_t reg, 132 uint8_t data) 133 { 134 struct i2c_msg seg; 135 uint8_t buf[] = {reg, data}; 136 137 seg.flags = 0; 138 seg.slave = slave; 139 seg.buf = buf; 140 seg.len = ARRAY_SIZE(buf); 141 142 return i2c_transfer(bus, &seg, 1); 143 } 144 145 /** 146 * Read multi-bytes from an I2C device with two bytes register address/offset 147 * with two segments in one frame 148 * 149 * [start][slave addr][w][register high addr][register low addr] 150 * [start][slave addr][r][data...][stop] 151 */ 152 static inline int i2c_2ba_read_bytes(unsigned int bus, uint8_t slave, uint16_t offset, 153 uint8_t *data, int len) 154 { 155 struct i2c_msg seg[2]; 156 uint8_t eeprom_offset[2]; 157 158 eeprom_offset[0] = offset >> 8; 159 eeprom_offset[1] = offset & 0xff; 160 161 seg[0].flags = 0; 162 seg[0].slave = slave; 163 seg[0].buf = eeprom_offset; 164 seg[0].len = sizeof(eeprom_offset); 165 seg[1].flags = I2C_M_RD; 166 seg[1].slave = slave; 167 seg[1].buf = data; 168 seg[1].len = len; 169 170 return i2c_transfer(bus, seg, ARRAY_SIZE(seg)); 171 } 172 173 #endif /* _DEVICE_I2C_SIMPLE_H_ */