Gan likun / mbed-dev11

1232

drivers/I2CSlave.h@0:06036f8bee2d, 2022-10-24 (annotated)

Committer:
ganlikun
Date:
Mon Oct 24 15:19:39 2022 +0000
Revision:
0:06036f8bee2d
11

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ganlikun 0:06036f8bee2d 1 /* mbed Microcontroller Library
ganlikun 0:06036f8bee2d 2 * Copyright (c) 2006-2013 ARM Limited
ganlikun 0:06036f8bee2d 3 *
ganlikun 0:06036f8bee2d 4 * Licensed under the Apache License, Version 2.0 (the "License");
ganlikun 0:06036f8bee2d 5 * you may not use this file except in compliance with the License.
ganlikun 0:06036f8bee2d 6 * You may obtain a copy of the License at
ganlikun 0:06036f8bee2d 7 *
ganlikun 0:06036f8bee2d 8 * http://www.apache.org/licenses/LICENSE-2.0
ganlikun 0:06036f8bee2d 9 *
ganlikun 0:06036f8bee2d 10 * Unless required by applicable law or agreed to in writing, software
ganlikun 0:06036f8bee2d 11 * distributed under the License is distributed on an "AS IS" BASIS,
ganlikun 0:06036f8bee2d 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
ganlikun 0:06036f8bee2d 13 * See the License for the specific language governing permissions and
ganlikun 0:06036f8bee2d 14 * limitations under the License.
ganlikun 0:06036f8bee2d 15 */
ganlikun 0:06036f8bee2d 16 #ifndef MBED_I2C_SLAVE_H
ganlikun 0:06036f8bee2d 17 #define MBED_I2C_SLAVE_H
ganlikun 0:06036f8bee2d 18
ganlikun 0:06036f8bee2d 19 #include "platform/platform.h"
ganlikun 0:06036f8bee2d 20
ganlikun 0:06036f8bee2d 21 #if defined (DEVICE_I2CSLAVE) || defined(DOXYGEN_ONLY)
ganlikun 0:06036f8bee2d 22
ganlikun 0:06036f8bee2d 23 #include "hal/i2c_api.h"
ganlikun 0:06036f8bee2d 24
ganlikun 0:06036f8bee2d 25 namespace mbed {
ganlikun 0:06036f8bee2d 26 /** \addtogroup drivers */
ganlikun 0:06036f8bee2d 27
ganlikun 0:06036f8bee2d 28 /** An I2C Slave, used for communicating with an I2C Master device
ganlikun 0:06036f8bee2d 29 *
ganlikun 0:06036f8bee2d 30 * @note Synchronization level: Not protected
ganlikun 0:06036f8bee2d 31 *
ganlikun 0:06036f8bee2d 32 * Example:
ganlikun 0:06036f8bee2d 33 * @code
ganlikun 0:06036f8bee2d 34 * // Simple I2C responder
ganlikun 0:06036f8bee2d 35 * #include <mbed.h>
ganlikun 0:06036f8bee2d 36 *
ganlikun 0:06036f8bee2d 37 * I2CSlave slave(p9, p10);
ganlikun 0:06036f8bee2d 38 *
ganlikun 0:06036f8bee2d 39 * int main() {
ganlikun 0:06036f8bee2d 40 * char buf[10];
ganlikun 0:06036f8bee2d 41 * char msg[] = "Slave!";
ganlikun 0:06036f8bee2d 42 *
ganlikun 0:06036f8bee2d 43 * slave.address(0xA0);
ganlikun 0:06036f8bee2d 44 * while (1) {
ganlikun 0:06036f8bee2d 45 * int i = slave.receive();
ganlikun 0:06036f8bee2d 46 * switch (i) {
ganlikun 0:06036f8bee2d 47 * case I2CSlave::ReadAddressed:
ganlikun 0:06036f8bee2d 48 * slave.write(msg, strlen(msg) + 1); // Includes null char
ganlikun 0:06036f8bee2d 49 * break;
ganlikun 0:06036f8bee2d 50 * case I2CSlave::WriteGeneral:
ganlikun 0:06036f8bee2d 51 * slave.read(buf, 10);
ganlikun 0:06036f8bee2d 52 * printf("Read G: %s\n", buf);
ganlikun 0:06036f8bee2d 53 * break;
ganlikun 0:06036f8bee2d 54 * case I2CSlave::WriteAddressed:
ganlikun 0:06036f8bee2d 55 * slave.read(buf, 10);
ganlikun 0:06036f8bee2d 56 * printf("Read A: %s\n", buf);
ganlikun 0:06036f8bee2d 57 * break;
ganlikun 0:06036f8bee2d 58 * }
ganlikun 0:06036f8bee2d 59 * for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer
ganlikun 0:06036f8bee2d 60 * }
ganlikun 0:06036f8bee2d 61 * }
ganlikun 0:06036f8bee2d 62 * @endcode
ganlikun 0:06036f8bee2d 63 * @ingroup drivers
ganlikun 0:06036f8bee2d 64 */
ganlikun 0:06036f8bee2d 65 class I2CSlave {
ganlikun 0:06036f8bee2d 66
ganlikun 0:06036f8bee2d 67 public:
ganlikun 0:06036f8bee2d 68 enum RxStatus {
ganlikun 0:06036f8bee2d 69 NoData = 0,
ganlikun 0:06036f8bee2d 70 ReadAddressed = 1,
ganlikun 0:06036f8bee2d 71 WriteGeneral = 2,
ganlikun 0:06036f8bee2d 72 WriteAddressed = 3
ganlikun 0:06036f8bee2d 73 };
ganlikun 0:06036f8bee2d 74
ganlikun 0:06036f8bee2d 75 /** Create an I2C Slave interface, connected to the specified pins.
ganlikun 0:06036f8bee2d 76 *
ganlikun 0:06036f8bee2d 77 * @param sda I2C data line pin
ganlikun 0:06036f8bee2d 78 * @param scl I2C clock line pin
ganlikun 0:06036f8bee2d 79 */
ganlikun 0:06036f8bee2d 80 I2CSlave(PinName sda, PinName scl);
ganlikun 0:06036f8bee2d 81
ganlikun 0:06036f8bee2d 82 /** Set the frequency of the I2C interface
ganlikun 0:06036f8bee2d 83 *
ganlikun 0:06036f8bee2d 84 * @param hz The bus frequency in hertz
ganlikun 0:06036f8bee2d 85 */
ganlikun 0:06036f8bee2d 86 void frequency(int hz);
ganlikun 0:06036f8bee2d 87
ganlikun 0:06036f8bee2d 88 /** Checks to see if this I2C Slave has been addressed.
ganlikun 0:06036f8bee2d 89 *
ganlikun 0:06036f8bee2d 90 * @returns
ganlikun 0:06036f8bee2d 91 * A status indicating if the device has been addressed, and how
ganlikun 0:06036f8bee2d 92 * - NoData - the slave has not been addressed
ganlikun 0:06036f8bee2d 93 * - ReadAddressed - the master has requested a read from this slave
ganlikun 0:06036f8bee2d 94 * - WriteAddressed - the master is writing to this slave
ganlikun 0:06036f8bee2d 95 * - WriteGeneral - the master is writing to all slave
ganlikun 0:06036f8bee2d 96 */
ganlikun 0:06036f8bee2d 97 int receive(void);
ganlikun 0:06036f8bee2d 98
ganlikun 0:06036f8bee2d 99 /** Read from an I2C master.
ganlikun 0:06036f8bee2d 100 *
ganlikun 0:06036f8bee2d 101 * @param data pointer to the byte array to read data in to
ganlikun 0:06036f8bee2d 102 * @param length maximum number of bytes to read
ganlikun 0:06036f8bee2d 103 *
ganlikun 0:06036f8bee2d 104 * @returns
ganlikun 0:06036f8bee2d 105 * 0 on success,
ganlikun 0:06036f8bee2d 106 * non-0 otherwise
ganlikun 0:06036f8bee2d 107 */
ganlikun 0:06036f8bee2d 108 int read(char *data, int length);
ganlikun 0:06036f8bee2d 109
ganlikun 0:06036f8bee2d 110 /** Read a single byte from an I2C master.
ganlikun 0:06036f8bee2d 111 *
ganlikun 0:06036f8bee2d 112 * @returns
ganlikun 0:06036f8bee2d 113 * the byte read
ganlikun 0:06036f8bee2d 114 */
ganlikun 0:06036f8bee2d 115 int read(void);
ganlikun 0:06036f8bee2d 116
ganlikun 0:06036f8bee2d 117 /** Write to an I2C master.
ganlikun 0:06036f8bee2d 118 *
ganlikun 0:06036f8bee2d 119 * @param data pointer to the byte array to be transmitted
ganlikun 0:06036f8bee2d 120 * @param length the number of bytes to transmite
ganlikun 0:06036f8bee2d 121 *
ganlikun 0:06036f8bee2d 122 * @returns
ganlikun 0:06036f8bee2d 123 * 0 on success,
ganlikun 0:06036f8bee2d 124 * non-0 otherwise
ganlikun 0:06036f8bee2d 125 */
ganlikun 0:06036f8bee2d 126 int write(const char *data, int length);
ganlikun 0:06036f8bee2d 127
ganlikun 0:06036f8bee2d 128 /** Write a single byte to an I2C master.
ganlikun 0:06036f8bee2d 129 *
ganlikun 0:06036f8bee2d 130 * @param data the byte to write
ganlikun 0:06036f8bee2d 131 *
ganlikun 0:06036f8bee2d 132 * @returns
ganlikun 0:06036f8bee2d 133 * '1' if an ACK was received,
ganlikun 0:06036f8bee2d 134 * '0' otherwise
ganlikun 0:06036f8bee2d 135 */
ganlikun 0:06036f8bee2d 136 int write(int data);
ganlikun 0:06036f8bee2d 137
ganlikun 0:06036f8bee2d 138 /** Sets the I2C slave address.
ganlikun 0:06036f8bee2d 139 *
ganlikun 0:06036f8bee2d 140 * @param address The address to set for the slave (ignoring the least
ganlikun 0:06036f8bee2d 141 * signifcant bit). If set to 0, the slave will only respond to the
ganlikun 0:06036f8bee2d 142 * general call address.
ganlikun 0:06036f8bee2d 143 */
ganlikun 0:06036f8bee2d 144 void address(int address);
ganlikun 0:06036f8bee2d 145
ganlikun 0:06036f8bee2d 146 /** Reset the I2C slave back into the known ready receiving state.
ganlikun 0:06036f8bee2d 147 */
ganlikun 0:06036f8bee2d 148 void stop(void);
ganlikun 0:06036f8bee2d 149
ganlikun 0:06036f8bee2d 150 protected:
ganlikun 0:06036f8bee2d 151 i2c_t _i2c;
ganlikun 0:06036f8bee2d 152 };
ganlikun 0:06036f8bee2d 153
ganlikun 0:06036f8bee2d 154 } // namespace mbed
ganlikun 0:06036f8bee2d 155
ganlikun 0:06036f8bee2d 156 #endif
ganlikun 0:06036f8bee2d 157
ganlikun 0:06036f8bee2d 158 #endif