Martin Woolley / microbit-dal

Solution for Bluetooth SIG hands-on training course

Dependencies:   BLE_API mbed-dev-bin nRF51822-bluetooth-mdw

Dependents:   microbit

Fork of microbit-dal-bluetooth-mdw_starter by Martin Woolley

source/drivers/MicroBitI2C.cpp@22:23d7b9a4b082, 2016-07-13 (annotated)

Committer:
LancasterUniversity
Date:
Wed Jul 13 12:17:54 2016 +0100
Revision:
22:23d7b9a4b082
Parent:
4:9fbeeb89de59 
Synchronized with git rev 7cf98c22

Author: James Devine

microbit-dal: patch for fiber_wake_on_event



fiber_wake_on_event used to crash after forking a FOB fiber.



It would attempt to obtain a new fiber context, and would place it on the wait queue.

Then when that fiber was paged in, the context of that fiber would not have been

initialised, as the function presumed schedule would be called immediately after

fiber initialisation.



This patch catches that edge case.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Jonathan Austin 1:8aa5cdb4ab67 1 /*
Jonathan Austin 1:8aa5cdb4ab67 2 The MIT License (MIT)
Jonathan Austin 1:8aa5cdb4ab67 3
Jonathan Austin 1:8aa5cdb4ab67 4 Copyright (c) 2016 British Broadcasting Corporation.
Jonathan Austin 1:8aa5cdb4ab67 5 This software is provided by Lancaster University by arrangement with the BBC.
Jonathan Austin 1:8aa5cdb4ab67 6
Jonathan Austin 1:8aa5cdb4ab67 7 Permission is hereby granted, free of charge, to any person obtaining a
Jonathan Austin 1:8aa5cdb4ab67 8 copy of this software and associated documentation files (the "Software"),
Jonathan Austin 1:8aa5cdb4ab67 9 to deal in the Software without restriction, including without limitation
Jonathan Austin 1:8aa5cdb4ab67 10 the rights to use, copy, modify, merge, publish, distribute, sublicense,
Jonathan Austin 1:8aa5cdb4ab67 11 and/or sell copies of the Software, and to permit persons to whom the
Jonathan Austin 1:8aa5cdb4ab67 12 Software is furnished to do so, subject to the following conditions:
Jonathan Austin 1:8aa5cdb4ab67 13
Jonathan Austin 1:8aa5cdb4ab67 14 The above copyright notice and this permission notice shall be included in
Jonathan Austin 1:8aa5cdb4ab67 15 all copies or substantial portions of the Software.
Jonathan Austin 1:8aa5cdb4ab67 16
Jonathan Austin 1:8aa5cdb4ab67 17 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
Jonathan Austin 1:8aa5cdb4ab67 18 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
Jonathan Austin 1:8aa5cdb4ab67 19 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
Jonathan Austin 1:8aa5cdb4ab67 20 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
Jonathan Austin 1:8aa5cdb4ab67 21 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
Jonathan Austin 1:8aa5cdb4ab67 22 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
Jonathan Austin 1:8aa5cdb4ab67 23 DEALINGS IN THE SOFTWARE.
Jonathan Austin 1:8aa5cdb4ab67 24 */
Jonathan Austin 1:8aa5cdb4ab67 25
Jonathan Austin 1:8aa5cdb4ab67 26 #include "MicroBitConfig.h"
Jonathan Austin 1:8aa5cdb4ab67 27 #include "MicroBitI2C.h"
Jonathan Austin 1:8aa5cdb4ab67 28 #include "ErrorNo.h"
Jonathan Austin 1:8aa5cdb4ab67 29 #include "twi_master.h"
Jonathan Austin 1:8aa5cdb4ab67 30 #include "nrf_delay.h"
Jonathan Austin 1:8aa5cdb4ab67 31
Jonathan Austin 1:8aa5cdb4ab67 32 /**
Jonathan Austin 1:8aa5cdb4ab67 33 * Constructor.
Jonathan Austin 1:8aa5cdb4ab67 34 *
Jonathan Austin 1:8aa5cdb4ab67 35 * Create an instance of MicroBitI2C for I2C communication.
Jonathan Austin 1:8aa5cdb4ab67 36 *
Jonathan Austin 1:8aa5cdb4ab67 37 * @param sda the Pin to be used for SDA
Jonathan Austin 1:8aa5cdb4ab67 38 *
Jonathan Austin 1:8aa5cdb4ab67 39 * @param scl the Pin to be used for SCL
Jonathan Austin 1:8aa5cdb4ab67 40 *
Jonathan Austin 1:8aa5cdb4ab67 41 * @code
Jonathan Austin 1:8aa5cdb4ab67 42 * MicroBitI2C i2c(I2C_SDA0, I2C_SCL0);
Jonathan Austin 1:8aa5cdb4ab67 43 * @endcode
Jonathan Austin 1:8aa5cdb4ab67 44 *
Jonathan Austin 1:8aa5cdb4ab67 45 * @note This class presents a wrapped mbed call to capture failed I2C operations caused by a known silicon bug in the nrf51822.
Jonathan Austin 1:8aa5cdb4ab67 46 * Attempts to automatically reset and restart the I2C hardware if this case is detected.
LancasterUniversity 4:9fbeeb89de59 47 * \par
Jonathan Austin 1:8aa5cdb4ab67 48 * For reference see PAN56 in:
LancasterUniversity 4:9fbeeb89de59 49 * \par
Jonathan Austin 1:8aa5cdb4ab67 50 * https://www.nordicsemi.com/eng/nordic/Products/nRF51822/PAN-nRF51822/24634
LancasterUniversity 4:9fbeeb89de59 51 * \par
Jonathan Austin 1:8aa5cdb4ab67 52 * v2.0 through to v2.4
Jonathan Austin 1:8aa5cdb4ab67 53 */
Jonathan Austin 1:8aa5cdb4ab67 54 MicroBitI2C::MicroBitI2C(PinName sda, PinName scl) : I2C(sda,scl)
Jonathan Austin 1:8aa5cdb4ab67 55 {
Jonathan Austin 1:8aa5cdb4ab67 56 this->retries = 0;
Jonathan Austin 1:8aa5cdb4ab67 57 }
Jonathan Austin 1:8aa5cdb4ab67 58
Jonathan Austin 1:8aa5cdb4ab67 59 /**
Jonathan Austin 1:8aa5cdb4ab67 60 * Performs a complete read transaction. The bottom bit of the address is forced to 1 to indicate a read.
Jonathan Austin 1:8aa5cdb4ab67 61 *
Jonathan Austin 1:8aa5cdb4ab67 62 * @param address 8-bit I2C slave address [ addr | 1 ]
Jonathan Austin 1:8aa5cdb4ab67 63 *
Jonathan Austin 1:8aa5cdb4ab67 64 * @param data A pointer to a byte buffer used for storing retrieved data.
Jonathan Austin 1:8aa5cdb4ab67 65 *
Jonathan Austin 1:8aa5cdb4ab67 66 * @param length Number of bytes to read.
Jonathan Austin 1:8aa5cdb4ab67 67 *
Jonathan Austin 1:8aa5cdb4ab67 68 * @param repeated if true, stop is not sent at the end. Defaults to false.
Jonathan Austin 1:8aa5cdb4ab67 69 *
Jonathan Austin 1:8aa5cdb4ab67 70 * @return MICROBIT_OK on success, MICROBIT_I2C_ERROR if an unresolved read failure is detected.
Jonathan Austin 1:8aa5cdb4ab67 71 */
Jonathan Austin 1:8aa5cdb4ab67 72 int MicroBitI2C::read(int address, char *data, int length, bool repeated)
Jonathan Austin 1:8aa5cdb4ab67 73 {
Jonathan Austin 1:8aa5cdb4ab67 74 int result = I2C::read(address,data,length,repeated);
Jonathan Austin 1:8aa5cdb4ab67 75
Jonathan Austin 1:8aa5cdb4ab67 76 //0 indicates a success, presume failure
Jonathan Austin 1:8aa5cdb4ab67 77 while(result != 0 && retries < MICROBIT_I2C_MAX_RETRIES)
Jonathan Austin 1:8aa5cdb4ab67 78 {
Jonathan Austin 1:8aa5cdb4ab67 79 _i2c.i2c->EVENTS_ERROR = 0;
Jonathan Austin 1:8aa5cdb4ab67 80 _i2c.i2c->ENABLE = TWI_ENABLE_ENABLE_Disabled << TWI_ENABLE_ENABLE_Pos;
Jonathan Austin 1:8aa5cdb4ab67 81 _i2c.i2c->POWER = 0;
Jonathan Austin 1:8aa5cdb4ab67 82 nrf_delay_us(5);
Jonathan Austin 1:8aa5cdb4ab67 83 _i2c.i2c->POWER = 1;
Jonathan Austin 1:8aa5cdb4ab67 84 _i2c.i2c->ENABLE = TWI_ENABLE_ENABLE_Enabled << TWI_ENABLE_ENABLE_Pos;
Jonathan Austin 1:8aa5cdb4ab67 85 twi_master_init_and_clear();
Jonathan Austin 1:8aa5cdb4ab67 86 result = I2C::read(address,data,length,repeated);
Jonathan Austin 1:8aa5cdb4ab67 87 retries++;
Jonathan Austin 1:8aa5cdb4ab67 88 }
Jonathan Austin 1:8aa5cdb4ab67 89
Jonathan Austin 1:8aa5cdb4ab67 90 if(result != 0)
Jonathan Austin 1:8aa5cdb4ab67 91 return MICROBIT_I2C_ERROR;
Jonathan Austin 1:8aa5cdb4ab67 92
Jonathan Austin 1:8aa5cdb4ab67 93 retries = 0;
Jonathan Austin 1:8aa5cdb4ab67 94 return MICROBIT_OK;
Jonathan Austin 1:8aa5cdb4ab67 95 }
Jonathan Austin 1:8aa5cdb4ab67 96
Jonathan Austin 1:8aa5cdb4ab67 97 /**
Jonathan Austin 1:8aa5cdb4ab67 98 * Performs a complete write transaction. The bottom bit of the address is forced to 0 to indicate a write.
Jonathan Austin 1:8aa5cdb4ab67 99 *
Jonathan Austin 1:8aa5cdb4ab67 100 * @param address 8-bit I2C slave address [ addr | 0 ]
Jonathan Austin 1:8aa5cdb4ab67 101 *
Jonathan Austin 1:8aa5cdb4ab67 102 * @param data A pointer to a byte buffer containing the data to write.
Jonathan Austin 1:8aa5cdb4ab67 103 *
Jonathan Austin 1:8aa5cdb4ab67 104 * @param length Number of bytes to write
Jonathan Austin 1:8aa5cdb4ab67 105 *
Jonathan Austin 1:8aa5cdb4ab67 106 * @param repeated if true, stop is not sent at the end. Defaults to false.
Jonathan Austin 1:8aa5cdb4ab67 107 *
Jonathan Austin 1:8aa5cdb4ab67 108 * @return MICROBIT_OK on success, MICROBIT_I2C_ERROR if an unresolved write failure is detected.
Jonathan Austin 1:8aa5cdb4ab67 109 */
Jonathan Austin 1:8aa5cdb4ab67 110 int MicroBitI2C::write(int address, const char *data, int length, bool repeated)
Jonathan Austin 1:8aa5cdb4ab67 111 {
Jonathan Austin 1:8aa5cdb4ab67 112 int result = I2C::write(address,data,length,repeated);
Jonathan Austin 1:8aa5cdb4ab67 113
Jonathan Austin 1:8aa5cdb4ab67 114 //0 indicates a success, presume failure
Jonathan Austin 1:8aa5cdb4ab67 115 while(result != 0 && retries < MICROBIT_I2C_MAX_RETRIES)
Jonathan Austin 1:8aa5cdb4ab67 116 {
Jonathan Austin 1:8aa5cdb4ab67 117 _i2c.i2c->EVENTS_ERROR = 0;
Jonathan Austin 1:8aa5cdb4ab67 118 _i2c.i2c->ENABLE = TWI_ENABLE_ENABLE_Disabled << TWI_ENABLE_ENABLE_Pos;
Jonathan Austin 1:8aa5cdb4ab67 119 _i2c.i2c->POWER = 0;
Jonathan Austin 1:8aa5cdb4ab67 120 nrf_delay_us(5);
Jonathan Austin 1:8aa5cdb4ab67 121 _i2c.i2c->POWER = 1;
Jonathan Austin 1:8aa5cdb4ab67 122 _i2c.i2c->ENABLE = TWI_ENABLE_ENABLE_Enabled << TWI_ENABLE_ENABLE_Pos;
Jonathan Austin 1:8aa5cdb4ab67 123
Jonathan Austin 1:8aa5cdb4ab67 124 twi_master_init_and_clear();
Jonathan Austin 1:8aa5cdb4ab67 125 result = I2C::write(address,data,length,repeated);
Jonathan Austin 1:8aa5cdb4ab67 126 retries++;
Jonathan Austin 1:8aa5cdb4ab67 127 }
Jonathan Austin 1:8aa5cdb4ab67 128
Jonathan Austin 1:8aa5cdb4ab67 129 if(result != 0)
Jonathan Austin 1:8aa5cdb4ab67 130 return MICROBIT_I2C_ERROR;
Jonathan Austin 1:8aa5cdb4ab67 131
Jonathan Austin 1:8aa5cdb4ab67 132 retries = 0;
Jonathan Austin 1:8aa5cdb4ab67 133 return MICROBIT_OK;
LancasterUniversity 4:9fbeeb89de59 134 }