MacroRat / MouseCode

Mouse code for the MacroRat

Dependencies:   ITG3200 QEI

mbed-dev/targets/TARGET_NORDIC/TARGET_NRF5/i2c_api.c@46:b156ef445742, 2017-06-03 (annotated)

Committer:
sahilmgandhi
Date:
Sat Jun 03 00:22:44 2017 +0000
Revision:
46:b156ef445742
Parent:
18:6a4db94011d3 
Final code for internal battlebot competition.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sahilmgandhi 18:6a4db94011d3 1 /*
sahilmgandhi 18:6a4db94011d3 2 * Copyright (c) 2017 Nordic Semiconductor ASA
sahilmgandhi 18:6a4db94011d3 3 * All rights reserved.
sahilmgandhi 18:6a4db94011d3 4 *
sahilmgandhi 18:6a4db94011d3 5 * Redistribution and use in source and binary forms, with or without modification,
sahilmgandhi 18:6a4db94011d3 6 * are permitted provided that the following conditions are met:
sahilmgandhi 18:6a4db94011d3 7 *
sahilmgandhi 18:6a4db94011d3 8 * 1. Redistributions of source code must retain the above copyright notice, this list
sahilmgandhi 18:6a4db94011d3 9 * of conditions and the following disclaimer.
sahilmgandhi 18:6a4db94011d3 10 *
sahilmgandhi 18:6a4db94011d3 11 * 2. Redistributions in binary form, except as embedded into a Nordic Semiconductor ASA
sahilmgandhi 18:6a4db94011d3 12 * integrated circuit in a product or a software update for such product, must reproduce
sahilmgandhi 18:6a4db94011d3 13 * the above copyright notice, this list of conditions and the following disclaimer in
sahilmgandhi 18:6a4db94011d3 14 * the documentation and/or other materials provided with the distribution.
sahilmgandhi 18:6a4db94011d3 15 *
sahilmgandhi 18:6a4db94011d3 16 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its contributors may be
sahilmgandhi 18:6a4db94011d3 17 * used to endorse or promote products derived from this software without specific prior
sahilmgandhi 18:6a4db94011d3 18 * written permission.
sahilmgandhi 18:6a4db94011d3 19 *
sahilmgandhi 18:6a4db94011d3 20 * 4. This software, with or without modification, must only be used with a
sahilmgandhi 18:6a4db94011d3 21 * Nordic Semiconductor ASA integrated circuit.
sahilmgandhi 18:6a4db94011d3 22 *
sahilmgandhi 18:6a4db94011d3 23 * 5. Any software provided in binary or object form under this license must not be reverse
sahilmgandhi 18:6a4db94011d3 24 * engineered, decompiled, modified and/or disassembled.
sahilmgandhi 18:6a4db94011d3 25 *
sahilmgandhi 18:6a4db94011d3 26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
sahilmgandhi 18:6a4db94011d3 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
sahilmgandhi 18:6a4db94011d3 28 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
sahilmgandhi 18:6a4db94011d3 29 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
sahilmgandhi 18:6a4db94011d3 30 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
sahilmgandhi 18:6a4db94011d3 31 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
sahilmgandhi 18:6a4db94011d3 32 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
sahilmgandhi 18:6a4db94011d3 33 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
sahilmgandhi 18:6a4db94011d3 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
sahilmgandhi 18:6a4db94011d3 35 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
sahilmgandhi 18:6a4db94011d3 36 *
sahilmgandhi 18:6a4db94011d3 37 */
sahilmgandhi 18:6a4db94011d3 38
sahilmgandhi 18:6a4db94011d3 39
sahilmgandhi 18:6a4db94011d3 40 #include "i2c_api.h"
sahilmgandhi 18:6a4db94011d3 41
sahilmgandhi 18:6a4db94011d3 42 #if DEVICE_I2C
sahilmgandhi 18:6a4db94011d3 43
sahilmgandhi 18:6a4db94011d3 44 #include "mbed_assert.h"
sahilmgandhi 18:6a4db94011d3 45 #include "mbed_error.h"
sahilmgandhi 18:6a4db94011d3 46 #include "nrf_twi.h"
sahilmgandhi 18:6a4db94011d3 47 #include "nrf_drv_common.h"
sahilmgandhi 18:6a4db94011d3 48 #include "nrf_drv_config.h"
sahilmgandhi 18:6a4db94011d3 49 #include "app_util_platform.h"
sahilmgandhi 18:6a4db94011d3 50 #include "nrf_gpio.h"
sahilmgandhi 18:6a4db94011d3 51 #include "nrf_delay.h"
sahilmgandhi 18:6a4db94011d3 52
sahilmgandhi 18:6a4db94011d3 53 // An arbitrary value used as the counter in loops waiting for given event
sahilmgandhi 18:6a4db94011d3 54 // (e.g. STOPPED), needed to avoid infinite loops (and not involve any timers
sahilmgandhi 18:6a4db94011d3 55 // or tickers).
sahilmgandhi 18:6a4db94011d3 56 #define TIMEOUT_VALUE 1000
sahilmgandhi 18:6a4db94011d3 57
sahilmgandhi 18:6a4db94011d3 58 #if DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 59 #define TWI_IDX(obj) ((obj)->i2c.twi_idx)
sahilmgandhi 18:6a4db94011d3 60 #else
sahilmgandhi 18:6a4db94011d3 61 #define TWI_IDX(obj) ((obj)->twi_idx)
sahilmgandhi 18:6a4db94011d3 62 #endif
sahilmgandhi 18:6a4db94011d3 63 #define TWI_INFO(obj) (&m_twi_info[TWI_IDX(obj)])
sahilmgandhi 18:6a4db94011d3 64
sahilmgandhi 18:6a4db94011d3 65 typedef struct {
sahilmgandhi 18:6a4db94011d3 66 bool initialized;
sahilmgandhi 18:6a4db94011d3 67 uint32_t pselsda;
sahilmgandhi 18:6a4db94011d3 68 uint32_t pselscl;
sahilmgandhi 18:6a4db94011d3 69 nrf_twi_frequency_t frequency;
sahilmgandhi 18:6a4db94011d3 70 bool start_twi;
sahilmgandhi 18:6a4db94011d3 71
sahilmgandhi 18:6a4db94011d3 72 #if DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 73 volatile bool active;
sahilmgandhi 18:6a4db94011d3 74 uint8_t const *tx;
sahilmgandhi 18:6a4db94011d3 75 size_t tx_length;
sahilmgandhi 18:6a4db94011d3 76 uint8_t *rx;
sahilmgandhi 18:6a4db94011d3 77 size_t rx_length;
sahilmgandhi 18:6a4db94011d3 78 bool stop;
sahilmgandhi 18:6a4db94011d3 79
sahilmgandhi 18:6a4db94011d3 80 volatile uint32_t events;
sahilmgandhi 18:6a4db94011d3 81 void (*handler)(void);
sahilmgandhi 18:6a4db94011d3 82 uint32_t evt_mask;
sahilmgandhi 18:6a4db94011d3 83 #endif // DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 84 } twi_info_t;
sahilmgandhi 18:6a4db94011d3 85 static twi_info_t m_twi_info[TWI_COUNT];
sahilmgandhi 18:6a4db94011d3 86
sahilmgandhi 18:6a4db94011d3 87 static NRF_TWI_Type * const m_twi_instances[TWI_COUNT] = {
sahilmgandhi 18:6a4db94011d3 88 #if TWI0_ENABLED
sahilmgandhi 18:6a4db94011d3 89 NRF_TWI0,
sahilmgandhi 18:6a4db94011d3 90 #endif
sahilmgandhi 18:6a4db94011d3 91 #if TWI1_ENABLED
sahilmgandhi 18:6a4db94011d3 92 NRF_TWI1,
sahilmgandhi 18:6a4db94011d3 93 #endif
sahilmgandhi 18:6a4db94011d3 94 };
sahilmgandhi 18:6a4db94011d3 95
sahilmgandhi 18:6a4db94011d3 96 void SPI0_TWI0_IRQHandler(void);
sahilmgandhi 18:6a4db94011d3 97 void SPI1_TWI1_IRQHandler(void);
sahilmgandhi 18:6a4db94011d3 98
sahilmgandhi 18:6a4db94011d3 99 static const peripheral_handler_desc_t twi_handlers[TWI_COUNT] =
sahilmgandhi 18:6a4db94011d3 100 {
sahilmgandhi 18:6a4db94011d3 101 #if TWI0_ENABLED
sahilmgandhi 18:6a4db94011d3 102 {
sahilmgandhi 18:6a4db94011d3 103 SPI0_TWI0_IRQn,
sahilmgandhi 18:6a4db94011d3 104 (uint32_t) SPI0_TWI0_IRQHandler
sahilmgandhi 18:6a4db94011d3 105 },
sahilmgandhi 18:6a4db94011d3 106 #endif
sahilmgandhi 18:6a4db94011d3 107 #if TWI1_ENABLED
sahilmgandhi 18:6a4db94011d3 108 {
sahilmgandhi 18:6a4db94011d3 109 SPI1_TWI1_IRQn,
sahilmgandhi 18:6a4db94011d3 110 (uint32_t) SPI1_TWI1_IRQHandler
sahilmgandhi 18:6a4db94011d3 111 }
sahilmgandhi 18:6a4db94011d3 112 #endif
sahilmgandhi 18:6a4db94011d3 113 };
sahilmgandhi 18:6a4db94011d3 114 #ifdef NRF51
sahilmgandhi 18:6a4db94011d3 115 #define TWI_IRQ_PRIORITY APP_IRQ_PRIORITY_LOW
sahilmgandhi 18:6a4db94011d3 116 #elif defined(NRF52)
sahilmgandhi 18:6a4db94011d3 117 #define TWI_IRQ_PRIORITY APP_IRQ_PRIORITY_LOWEST
sahilmgandhi 18:6a4db94011d3 118 #endif
sahilmgandhi 18:6a4db94011d3 119
sahilmgandhi 18:6a4db94011d3 120
sahilmgandhi 18:6a4db94011d3 121 #if DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 122 static void start_asynch_rx(twi_info_t *twi_info, NRF_TWI_Type *twi)
sahilmgandhi 18:6a4db94011d3 123 {
sahilmgandhi 18:6a4db94011d3 124 if (twi_info->rx_length == 1 && twi_info->stop) {
sahilmgandhi 18:6a4db94011d3 125 nrf_twi_shorts_set(twi, NRF_TWI_SHORT_BB_STOP_MASK);
sahilmgandhi 18:6a4db94011d3 126 } else {
sahilmgandhi 18:6a4db94011d3 127 nrf_twi_shorts_set(twi, NRF_TWI_SHORT_BB_SUSPEND_MASK);
sahilmgandhi 18:6a4db94011d3 128 }
sahilmgandhi 18:6a4db94011d3 129 nrf_twi_task_trigger(twi, NRF_TWI_TASK_STARTRX);
sahilmgandhi 18:6a4db94011d3 130 }
sahilmgandhi 18:6a4db94011d3 131
sahilmgandhi 18:6a4db94011d3 132 static void twi_irq_handler(uint8_t instance_idx)
sahilmgandhi 18:6a4db94011d3 133 {
sahilmgandhi 18:6a4db94011d3 134 twi_info_t *twi_info = &m_twi_info[instance_idx];
sahilmgandhi 18:6a4db94011d3 135
sahilmgandhi 18:6a4db94011d3 136 NRF_TWI_Type *twi = m_twi_instances[instance_idx];
sahilmgandhi 18:6a4db94011d3 137 if (nrf_twi_event_check(twi, NRF_TWI_EVENT_ERROR)) {
sahilmgandhi 18:6a4db94011d3 138 nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR);
sahilmgandhi 18:6a4db94011d3 139
sahilmgandhi 18:6a4db94011d3 140 // In case of an error, force STOP.
sahilmgandhi 18:6a4db94011d3 141 // The current transfer may be suspended (if it is RX), so it must be
sahilmgandhi 18:6a4db94011d3 142 // resumed before the STOP task is triggered.
sahilmgandhi 18:6a4db94011d3 143 nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME);
sahilmgandhi 18:6a4db94011d3 144 nrf_twi_task_trigger(twi, NRF_TWI_TASK_STOP);
sahilmgandhi 18:6a4db94011d3 145
sahilmgandhi 18:6a4db94011d3 146 uint32_t errorsrc = nrf_twi_errorsrc_get_and_clear(twi);
sahilmgandhi 18:6a4db94011d3 147 twi_info->events |= I2C_EVENT_ERROR;
sahilmgandhi 18:6a4db94011d3 148 if (errorsrc & NRF_TWI_ERROR_ADDRESS_NACK) {
sahilmgandhi 18:6a4db94011d3 149 twi_info->events |= I2C_EVENT_ERROR_NO_SLAVE;
sahilmgandhi 18:6a4db94011d3 150 }
sahilmgandhi 18:6a4db94011d3 151 if (errorsrc & NRF_TWI_ERROR_DATA_NACK) {
sahilmgandhi 18:6a4db94011d3 152 twi_info->events |= I2C_EVENT_TRANSFER_EARLY_NACK;
sahilmgandhi 18:6a4db94011d3 153 }
sahilmgandhi 18:6a4db94011d3 154 }
sahilmgandhi 18:6a4db94011d3 155
sahilmgandhi 18:6a4db94011d3 156 bool finished = false;
sahilmgandhi 18:6a4db94011d3 157
sahilmgandhi 18:6a4db94011d3 158 if (nrf_twi_event_check(twi, NRF_TWI_EVENT_TXDSENT)) {
sahilmgandhi 18:6a4db94011d3 159 nrf_twi_event_clear(twi, NRF_TWI_EVENT_TXDSENT);
sahilmgandhi 18:6a4db94011d3 160
sahilmgandhi 18:6a4db94011d3 161 MBED_ASSERT(twi_info->tx_length > 0);
sahilmgandhi 18:6a4db94011d3 162 --(twi_info->tx_length);
sahilmgandhi 18:6a4db94011d3 163 // Send next byte if there is still something to be sent.
sahilmgandhi 18:6a4db94011d3 164 if (twi_info->tx_length > 0) {
sahilmgandhi 18:6a4db94011d3 165 nrf_twi_txd_set(twi, *(twi_info->tx));
sahilmgandhi 18:6a4db94011d3 166 ++(twi_info->tx);
sahilmgandhi 18:6a4db94011d3 167 // It TX is done, start RX if requested.
sahilmgandhi 18:6a4db94011d3 168 } else if (twi_info->rx_length > 0) {
sahilmgandhi 18:6a4db94011d3 169 start_asynch_rx(twi_info, twi);
sahilmgandhi 18:6a4db94011d3 170 // If there is nothing more to do, finalize the transfer.
sahilmgandhi 18:6a4db94011d3 171 } else {
sahilmgandhi 18:6a4db94011d3 172 if (twi_info->stop) {
sahilmgandhi 18:6a4db94011d3 173 nrf_twi_task_trigger(twi, NRF_TWI_TASK_STOP);
sahilmgandhi 18:6a4db94011d3 174 } else {
sahilmgandhi 18:6a4db94011d3 175 nrf_twi_task_trigger(twi, NRF_TWI_TASK_SUSPEND);
sahilmgandhi 18:6a4db94011d3 176 finished = true;
sahilmgandhi 18:6a4db94011d3 177 }
sahilmgandhi 18:6a4db94011d3 178 twi_info->events |= I2C_EVENT_TRANSFER_COMPLETE;
sahilmgandhi 18:6a4db94011d3 179 }
sahilmgandhi 18:6a4db94011d3 180 }
sahilmgandhi 18:6a4db94011d3 181
sahilmgandhi 18:6a4db94011d3 182 if (nrf_twi_event_check(twi, NRF_TWI_EVENT_RXDREADY)) {
sahilmgandhi 18:6a4db94011d3 183 nrf_twi_event_clear(twi, NRF_TWI_EVENT_RXDREADY);
sahilmgandhi 18:6a4db94011d3 184
sahilmgandhi 18:6a4db94011d3 185 MBED_ASSERT(twi_info->rx_length > 0);
sahilmgandhi 18:6a4db94011d3 186 *(twi_info->rx) = nrf_twi_rxd_get(twi);
sahilmgandhi 18:6a4db94011d3 187 ++(twi_info->rx);
sahilmgandhi 18:6a4db94011d3 188 --(twi_info->rx_length);
sahilmgandhi 18:6a4db94011d3 189
sahilmgandhi 18:6a4db94011d3 190 if (twi_info->rx_length > 0) {
sahilmgandhi 18:6a4db94011d3 191 // If more bytes should be received, resume the transfer
sahilmgandhi 18:6a4db94011d3 192 // (in case the stop condition should be generated after the next
sahilmgandhi 18:6a4db94011d3 193 // byte, change the shortcuts configuration first).
sahilmgandhi 18:6a4db94011d3 194 if (twi_info->rx_length == 1 && twi_info->stop) {
sahilmgandhi 18:6a4db94011d3 195 nrf_twi_shorts_set(twi, NRF_TWI_SHORT_BB_STOP_MASK);
sahilmgandhi 18:6a4db94011d3 196 }
sahilmgandhi 18:6a4db94011d3 197 nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME);
sahilmgandhi 18:6a4db94011d3 198 } else {
sahilmgandhi 18:6a4db94011d3 199 // If all requested bytes were received, finalize the transfer.
sahilmgandhi 18:6a4db94011d3 200 finished = true;
sahilmgandhi 18:6a4db94011d3 201 twi_info->events |= I2C_EVENT_TRANSFER_COMPLETE;
sahilmgandhi 18:6a4db94011d3 202 }
sahilmgandhi 18:6a4db94011d3 203 }
sahilmgandhi 18:6a4db94011d3 204
sahilmgandhi 18:6a4db94011d3 205 if (finished ||
sahilmgandhi 18:6a4db94011d3 206 nrf_twi_event_check(twi, NRF_TWI_EVENT_STOPPED) ||
sahilmgandhi 18:6a4db94011d3 207 (nrf_twi_int_enable_check(twi, NRF_TWI_INT_SUSPENDED_MASK) &&
sahilmgandhi 18:6a4db94011d3 208 nrf_twi_event_check(twi, NRF_TWI_EVENT_SUSPENDED))) {
sahilmgandhi 18:6a4db94011d3 209 // There is no need to clear the STOPPED and SUSPENDED events here,
sahilmgandhi 18:6a4db94011d3 210 // they will no longer generate the interrupt - see below.
sahilmgandhi 18:6a4db94011d3 211
sahilmgandhi 18:6a4db94011d3 212 nrf_twi_shorts_set(twi, 0);
sahilmgandhi 18:6a4db94011d3 213 // Disable all interrupt sources.
sahilmgandhi 18:6a4db94011d3 214 nrf_twi_int_disable(twi, UINT32_MAX);
sahilmgandhi 18:6a4db94011d3 215 twi_info->active = false;
sahilmgandhi 18:6a4db94011d3 216
sahilmgandhi 18:6a4db94011d3 217 if (twi_info->handler) {
sahilmgandhi 18:6a4db94011d3 218 twi_info->handler();
sahilmgandhi 18:6a4db94011d3 219 }
sahilmgandhi 18:6a4db94011d3 220 }
sahilmgandhi 18:6a4db94011d3 221 }
sahilmgandhi 18:6a4db94011d3 222
sahilmgandhi 18:6a4db94011d3 223 #if TWI0_ENABLED
sahilmgandhi 18:6a4db94011d3 224 static void irq_handler_twi0(void)
sahilmgandhi 18:6a4db94011d3 225 {
sahilmgandhi 18:6a4db94011d3 226 twi_irq_handler(TWI0_INSTANCE_INDEX);
sahilmgandhi 18:6a4db94011d3 227 }
sahilmgandhi 18:6a4db94011d3 228 #endif
sahilmgandhi 18:6a4db94011d3 229 #if TWI1_ENABLED
sahilmgandhi 18:6a4db94011d3 230 static void irq_handler_twi1(void)
sahilmgandhi 18:6a4db94011d3 231 {
sahilmgandhi 18:6a4db94011d3 232 twi_irq_handler(TWI1_INSTANCE_INDEX);
sahilmgandhi 18:6a4db94011d3 233 }
sahilmgandhi 18:6a4db94011d3 234 #endif
sahilmgandhi 18:6a4db94011d3 235 static nrf_drv_irq_handler_t const m_twi_irq_handlers[TWI_COUNT] =
sahilmgandhi 18:6a4db94011d3 236 {
sahilmgandhi 18:6a4db94011d3 237 #if TWI0_ENABLED
sahilmgandhi 18:6a4db94011d3 238 irq_handler_twi0,
sahilmgandhi 18:6a4db94011d3 239 #endif
sahilmgandhi 18:6a4db94011d3 240 #if TWI1_ENABLED
sahilmgandhi 18:6a4db94011d3 241 irq_handler_twi1,
sahilmgandhi 18:6a4db94011d3 242 #endif
sahilmgandhi 18:6a4db94011d3 243 };
sahilmgandhi 18:6a4db94011d3 244 #endif // DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 245
sahilmgandhi 18:6a4db94011d3 246
sahilmgandhi 18:6a4db94011d3 247 static void configure_twi_pin(uint32_t pin, nrf_gpio_pin_dir_t dir)
sahilmgandhi 18:6a4db94011d3 248 {
sahilmgandhi 18:6a4db94011d3 249 nrf_gpio_cfg(pin,
sahilmgandhi 18:6a4db94011d3 250 dir,
sahilmgandhi 18:6a4db94011d3 251 NRF_GPIO_PIN_INPUT_CONNECT,
sahilmgandhi 18:6a4db94011d3 252 NRF_GPIO_PIN_PULLUP,
sahilmgandhi 18:6a4db94011d3 253 NRF_GPIO_PIN_S0D1,
sahilmgandhi 18:6a4db94011d3 254 NRF_GPIO_PIN_NOSENSE);
sahilmgandhi 18:6a4db94011d3 255 }
sahilmgandhi 18:6a4db94011d3 256
sahilmgandhi 18:6a4db94011d3 257 static void twi_clear_bus(twi_info_t *twi_info)
sahilmgandhi 18:6a4db94011d3 258 {
sahilmgandhi 18:6a4db94011d3 259 // Try to set SDA high, and check if no slave tries to drive it low.
sahilmgandhi 18:6a4db94011d3 260 nrf_gpio_pin_set(twi_info->pselsda);
sahilmgandhi 18:6a4db94011d3 261 configure_twi_pin(twi_info->pselsda, NRF_GPIO_PIN_DIR_OUTPUT);
sahilmgandhi 18:6a4db94011d3 262 // In case SDA is low, make up to 9 cycles on SCL line to help the slave
sahilmgandhi 18:6a4db94011d3 263 // that pulls SDA low release it.
sahilmgandhi 18:6a4db94011d3 264 if (!nrf_gpio_pin_read(twi_info->pselsda)) {
sahilmgandhi 18:6a4db94011d3 265 nrf_gpio_pin_set(twi_info->pselscl);
sahilmgandhi 18:6a4db94011d3 266 configure_twi_pin(twi_info->pselscl, NRF_GPIO_PIN_DIR_OUTPUT);
sahilmgandhi 18:6a4db94011d3 267 nrf_delay_us(4);
sahilmgandhi 18:6a4db94011d3 268
sahilmgandhi 18:6a4db94011d3 269 for (int i = 0; i < 9; i++) {
sahilmgandhi 18:6a4db94011d3 270 if (nrf_gpio_pin_read(twi_info->pselsda)) {
sahilmgandhi 18:6a4db94011d3 271 break;
sahilmgandhi 18:6a4db94011d3 272 }
sahilmgandhi 18:6a4db94011d3 273 nrf_gpio_pin_clear(twi_info->pselscl);
sahilmgandhi 18:6a4db94011d3 274 nrf_delay_us(4);
sahilmgandhi 18:6a4db94011d3 275 nrf_gpio_pin_set(twi_info->pselscl);
sahilmgandhi 18:6a4db94011d3 276 nrf_delay_us(4);
sahilmgandhi 18:6a4db94011d3 277 }
sahilmgandhi 18:6a4db94011d3 278
sahilmgandhi 18:6a4db94011d3 279 // Finally, generate STOP condition to put the bus into initial state.
sahilmgandhi 18:6a4db94011d3 280 nrf_gpio_pin_clear(twi_info->pselsda);
sahilmgandhi 18:6a4db94011d3 281 nrf_delay_us(4);
sahilmgandhi 18:6a4db94011d3 282 nrf_gpio_pin_set(twi_info->pselsda);
sahilmgandhi 18:6a4db94011d3 283 }
sahilmgandhi 18:6a4db94011d3 284 }
sahilmgandhi 18:6a4db94011d3 285
sahilmgandhi 18:6a4db94011d3 286 void i2c_init(i2c_t *obj, PinName sda, PinName scl)
sahilmgandhi 18:6a4db94011d3 287 {
sahilmgandhi 18:6a4db94011d3 288 int i;
sahilmgandhi 18:6a4db94011d3 289 for (i = 0; i < TWI_COUNT; ++i) {
sahilmgandhi 18:6a4db94011d3 290 if (m_twi_info[i].initialized &&
sahilmgandhi 18:6a4db94011d3 291 m_twi_info[i].pselsda == (uint32_t)sda &&
sahilmgandhi 18:6a4db94011d3 292 m_twi_info[i].pselscl == (uint32_t)scl) {
sahilmgandhi 18:6a4db94011d3 293 TWI_IDX(obj) = i;
sahilmgandhi 18:6a4db94011d3 294 TWI_INFO(obj)->frequency = NRF_TWI_FREQ_100K;
sahilmgandhi 18:6a4db94011d3 295 i2c_reset(obj);
sahilmgandhi 18:6a4db94011d3 296 return;
sahilmgandhi 18:6a4db94011d3 297 }
sahilmgandhi 18:6a4db94011d3 298 }
sahilmgandhi 18:6a4db94011d3 299
sahilmgandhi 18:6a4db94011d3 300 for (i = 0; i < TWI_COUNT; ++i) {
sahilmgandhi 18:6a4db94011d3 301 if (!m_twi_info[i].initialized) {
sahilmgandhi 18:6a4db94011d3 302 TWI_IDX(obj) = i;
sahilmgandhi 18:6a4db94011d3 303
sahilmgandhi 18:6a4db94011d3 304 twi_info_t *twi_info = TWI_INFO(obj);
sahilmgandhi 18:6a4db94011d3 305 twi_info->initialized = true;
sahilmgandhi 18:6a4db94011d3 306 twi_info->pselsda = (uint32_t)sda;
sahilmgandhi 18:6a4db94011d3 307 twi_info->pselscl = (uint32_t)scl;
sahilmgandhi 18:6a4db94011d3 308 twi_info->frequency = NRF_TWI_FREQ_100K;
sahilmgandhi 18:6a4db94011d3 309 twi_info->start_twi = false;
sahilmgandhi 18:6a4db94011d3 310 #if DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 311 twi_info->active = false;
sahilmgandhi 18:6a4db94011d3 312 #endif
sahilmgandhi 18:6a4db94011d3 313
sahilmgandhi 18:6a4db94011d3 314 twi_clear_bus(twi_info);
sahilmgandhi 18:6a4db94011d3 315
sahilmgandhi 18:6a4db94011d3 316 configure_twi_pin(twi_info->pselsda, NRF_GPIO_PIN_DIR_INPUT);
sahilmgandhi 18:6a4db94011d3 317 configure_twi_pin(twi_info->pselscl, NRF_GPIO_PIN_DIR_INPUT);
sahilmgandhi 18:6a4db94011d3 318
sahilmgandhi 18:6a4db94011d3 319 i2c_reset(obj);
sahilmgandhi 18:6a4db94011d3 320
sahilmgandhi 18:6a4db94011d3 321 #if DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 322 nrf_drv_common_per_res_acquire(m_twi_instances[i],
sahilmgandhi 18:6a4db94011d3 323 m_twi_irq_handlers[i]);
sahilmgandhi 18:6a4db94011d3 324 NVIC_SetVector(twi_handlers[i].IRQn, twi_handlers[i].vector);
sahilmgandhi 18:6a4db94011d3 325 nrf_drv_common_irq_enable(twi_handlers[i].IRQn, TWI_IRQ_PRIORITY);
sahilmgandhi 18:6a4db94011d3 326 #endif
sahilmgandhi 18:6a4db94011d3 327
sahilmgandhi 18:6a4db94011d3 328 return;
sahilmgandhi 18:6a4db94011d3 329 }
sahilmgandhi 18:6a4db94011d3 330 }
sahilmgandhi 18:6a4db94011d3 331
sahilmgandhi 18:6a4db94011d3 332 error("No available I2C peripheral\r\n");
sahilmgandhi 18:6a4db94011d3 333 }
sahilmgandhi 18:6a4db94011d3 334
sahilmgandhi 18:6a4db94011d3 335 void i2c_reset(i2c_t *obj)
sahilmgandhi 18:6a4db94011d3 336 {
sahilmgandhi 18:6a4db94011d3 337 twi_info_t *twi_info = TWI_INFO(obj);
sahilmgandhi 18:6a4db94011d3 338 NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)];
sahilmgandhi 18:6a4db94011d3 339
sahilmgandhi 18:6a4db94011d3 340 nrf_twi_disable(twi);
sahilmgandhi 18:6a4db94011d3 341 nrf_twi_pins_set(twi, twi_info->pselscl, twi_info->pselsda);
sahilmgandhi 18:6a4db94011d3 342 nrf_twi_frequency_set(twi, twi_info->frequency);
sahilmgandhi 18:6a4db94011d3 343 nrf_twi_enable(twi);
sahilmgandhi 18:6a4db94011d3 344 }
sahilmgandhi 18:6a4db94011d3 345
sahilmgandhi 18:6a4db94011d3 346 int i2c_start(i2c_t *obj)
sahilmgandhi 18:6a4db94011d3 347 {
sahilmgandhi 18:6a4db94011d3 348 twi_info_t *twi_info = TWI_INFO(obj);
sahilmgandhi 18:6a4db94011d3 349 #if DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 350 if (twi_info->active) {
sahilmgandhi 18:6a4db94011d3 351 return I2C_ERROR_BUS_BUSY;
sahilmgandhi 18:6a4db94011d3 352 }
sahilmgandhi 18:6a4db94011d3 353 #endif
sahilmgandhi 18:6a4db94011d3 354 twi_info->start_twi = true;
sahilmgandhi 18:6a4db94011d3 355
sahilmgandhi 18:6a4db94011d3 356 return 0;
sahilmgandhi 18:6a4db94011d3 357 }
sahilmgandhi 18:6a4db94011d3 358
sahilmgandhi 18:6a4db94011d3 359 int i2c_stop(i2c_t *obj)
sahilmgandhi 18:6a4db94011d3 360 {
sahilmgandhi 18:6a4db94011d3 361 NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)];
sahilmgandhi 18:6a4db94011d3 362
sahilmgandhi 18:6a4db94011d3 363 // The current transfer may be suspended (if it is RX), so it must be
sahilmgandhi 18:6a4db94011d3 364 // resumed before the STOP task is triggered.
sahilmgandhi 18:6a4db94011d3 365 nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME);
sahilmgandhi 18:6a4db94011d3 366 nrf_twi_task_trigger(twi, NRF_TWI_TASK_STOP);
sahilmgandhi 18:6a4db94011d3 367 uint32_t remaining_time = TIMEOUT_VALUE;
sahilmgandhi 18:6a4db94011d3 368 do {
sahilmgandhi 18:6a4db94011d3 369 if (nrf_twi_event_check(twi, NRF_TWI_EVENT_STOPPED)) {
sahilmgandhi 18:6a4db94011d3 370 return 0;
sahilmgandhi 18:6a4db94011d3 371 }
sahilmgandhi 18:6a4db94011d3 372 } while (--remaining_time);
sahilmgandhi 18:6a4db94011d3 373
sahilmgandhi 18:6a4db94011d3 374 return 1;
sahilmgandhi 18:6a4db94011d3 375 }
sahilmgandhi 18:6a4db94011d3 376
sahilmgandhi 18:6a4db94011d3 377 void i2c_frequency(i2c_t *obj, int hz)
sahilmgandhi 18:6a4db94011d3 378 {
sahilmgandhi 18:6a4db94011d3 379 twi_info_t *twi_info = TWI_INFO(obj);
sahilmgandhi 18:6a4db94011d3 380 NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)];
sahilmgandhi 18:6a4db94011d3 381
sahilmgandhi 18:6a4db94011d3 382 if (hz < 250000) {
sahilmgandhi 18:6a4db94011d3 383 twi_info->frequency = NRF_TWI_FREQ_100K;
sahilmgandhi 18:6a4db94011d3 384 } else if (hz < 400000) {
sahilmgandhi 18:6a4db94011d3 385 twi_info->frequency = NRF_TWI_FREQ_250K;
sahilmgandhi 18:6a4db94011d3 386 } else {
sahilmgandhi 18:6a4db94011d3 387 twi_info->frequency = NRF_TWI_FREQ_400K;
sahilmgandhi 18:6a4db94011d3 388 }
sahilmgandhi 18:6a4db94011d3 389 nrf_twi_frequency_set(twi, twi_info->frequency);
sahilmgandhi 18:6a4db94011d3 390 }
sahilmgandhi 18:6a4db94011d3 391
sahilmgandhi 18:6a4db94011d3 392 static uint8_t twi_address(int i2c_address)
sahilmgandhi 18:6a4db94011d3 393 {
sahilmgandhi 18:6a4db94011d3 394 // The TWI peripheral requires 7-bit slave address (without R/W bit).
sahilmgandhi 18:6a4db94011d3 395 return (i2c_address >> 1);
sahilmgandhi 18:6a4db94011d3 396 }
sahilmgandhi 18:6a4db94011d3 397
sahilmgandhi 18:6a4db94011d3 398 static void start_twi_read(NRF_TWI_Type *twi, int address)
sahilmgandhi 18:6a4db94011d3 399 {
sahilmgandhi 18:6a4db94011d3 400 nrf_twi_event_clear(twi, NRF_TWI_EVENT_STOPPED);
sahilmgandhi 18:6a4db94011d3 401 nrf_twi_event_clear(twi, NRF_TWI_EVENT_RXDREADY);
sahilmgandhi 18:6a4db94011d3 402 nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR);
sahilmgandhi 18:6a4db94011d3 403 (void)nrf_twi_errorsrc_get_and_clear(twi);
sahilmgandhi 18:6a4db94011d3 404
sahilmgandhi 18:6a4db94011d3 405 nrf_twi_shorts_set(twi, NRF_TWI_SHORT_BB_SUSPEND_MASK);
sahilmgandhi 18:6a4db94011d3 406
sahilmgandhi 18:6a4db94011d3 407 nrf_twi_address_set(twi, twi_address(address));
sahilmgandhi 18:6a4db94011d3 408 nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME);
sahilmgandhi 18:6a4db94011d3 409 nrf_twi_task_trigger(twi, NRF_TWI_TASK_STARTRX);
sahilmgandhi 18:6a4db94011d3 410 }
sahilmgandhi 18:6a4db94011d3 411
sahilmgandhi 18:6a4db94011d3 412 int i2c_read(i2c_t *obj, int address, char *data, int length, int stop)
sahilmgandhi 18:6a4db94011d3 413 {
sahilmgandhi 18:6a4db94011d3 414 // Zero-length RX transfers are not supported. Such transfers cannot
sahilmgandhi 18:6a4db94011d3 415 // be easily achieved with TWI peripheral (some dirty tricks would be
sahilmgandhi 18:6a4db94011d3 416 // required for this), and they are actually useless (TX can be used
sahilmgandhi 18:6a4db94011d3 417 // to check if the address is acknowledged by a slave).
sahilmgandhi 18:6a4db94011d3 418 MBED_ASSERT(length > 0);
sahilmgandhi 18:6a4db94011d3 419
sahilmgandhi 18:6a4db94011d3 420 twi_info_t *twi_info = TWI_INFO(obj);
sahilmgandhi 18:6a4db94011d3 421 #if DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 422 if (twi_info->active) {
sahilmgandhi 18:6a4db94011d3 423 return I2C_ERROR_BUS_BUSY;
sahilmgandhi 18:6a4db94011d3 424 }
sahilmgandhi 18:6a4db94011d3 425 #endif
sahilmgandhi 18:6a4db94011d3 426 twi_info->start_twi = false;
sahilmgandhi 18:6a4db94011d3 427
sahilmgandhi 18:6a4db94011d3 428 NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)];
sahilmgandhi 18:6a4db94011d3 429 start_twi_read(twi, address);
sahilmgandhi 18:6a4db94011d3 430
sahilmgandhi 18:6a4db94011d3 431 int result = length;
sahilmgandhi 18:6a4db94011d3 432 while (length > 0) {
sahilmgandhi 18:6a4db94011d3 433 int byte_read_result = i2c_byte_read(obj, (stop && length == 1));
sahilmgandhi 18:6a4db94011d3 434 if (byte_read_result < 0) {
sahilmgandhi 18:6a4db94011d3 435 // When an error occurs, return the number of bytes that have been
sahilmgandhi 18:6a4db94011d3 436 // received successfully.
sahilmgandhi 18:6a4db94011d3 437 result -= length;
sahilmgandhi 18:6a4db94011d3 438 // Force STOP condition.
sahilmgandhi 18:6a4db94011d3 439 stop = 1;
sahilmgandhi 18:6a4db94011d3 440 break;
sahilmgandhi 18:6a4db94011d3 441 }
sahilmgandhi 18:6a4db94011d3 442 *data++ = (uint8_t)byte_read_result;
sahilmgandhi 18:6a4db94011d3 443 --length;
sahilmgandhi 18:6a4db94011d3 444 }
sahilmgandhi 18:6a4db94011d3 445
sahilmgandhi 18:6a4db94011d3 446 if (stop) {
sahilmgandhi 18:6a4db94011d3 447 (void)i2c_stop(obj);
sahilmgandhi 18:6a4db94011d3 448 }
sahilmgandhi 18:6a4db94011d3 449
sahilmgandhi 18:6a4db94011d3 450 return result;
sahilmgandhi 18:6a4db94011d3 451 }
sahilmgandhi 18:6a4db94011d3 452
sahilmgandhi 18:6a4db94011d3 453 static uint8_t twi_byte_write(NRF_TWI_Type *twi, uint8_t data)
sahilmgandhi 18:6a4db94011d3 454 {
sahilmgandhi 18:6a4db94011d3 455 nrf_twi_event_clear(twi, NRF_TWI_EVENT_TXDSENT);
sahilmgandhi 18:6a4db94011d3 456 nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR);
sahilmgandhi 18:6a4db94011d3 457
sahilmgandhi 18:6a4db94011d3 458 nrf_twi_txd_set(twi, data);
sahilmgandhi 18:6a4db94011d3 459 uint32_t remaining_time = TIMEOUT_VALUE;
sahilmgandhi 18:6a4db94011d3 460 do {
sahilmgandhi 18:6a4db94011d3 461 if (nrf_twi_event_check(twi, NRF_TWI_EVENT_TXDSENT)) {
sahilmgandhi 18:6a4db94011d3 462 nrf_twi_event_clear(twi, NRF_TWI_EVENT_TXDSENT);
sahilmgandhi 18:6a4db94011d3 463 return 1; // ACK received
sahilmgandhi 18:6a4db94011d3 464 }
sahilmgandhi 18:6a4db94011d3 465 if (nrf_twi_event_check(twi, NRF_TWI_EVENT_ERROR)) {
sahilmgandhi 18:6a4db94011d3 466 nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR);
sahilmgandhi 18:6a4db94011d3 467 return 0; // some error occurred
sahilmgandhi 18:6a4db94011d3 468 }
sahilmgandhi 18:6a4db94011d3 469 } while (--remaining_time);
sahilmgandhi 18:6a4db94011d3 470
sahilmgandhi 18:6a4db94011d3 471 return 2; // timeout;
sahilmgandhi 18:6a4db94011d3 472 }
sahilmgandhi 18:6a4db94011d3 473
sahilmgandhi 18:6a4db94011d3 474 static void start_twi_write(NRF_TWI_Type *twi, int address)
sahilmgandhi 18:6a4db94011d3 475 {
sahilmgandhi 18:6a4db94011d3 476 nrf_twi_event_clear(twi, NRF_TWI_EVENT_STOPPED);
sahilmgandhi 18:6a4db94011d3 477 nrf_twi_event_clear(twi, NRF_TWI_EVENT_TXDSENT);
sahilmgandhi 18:6a4db94011d3 478 nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR);
sahilmgandhi 18:6a4db94011d3 479 (void)nrf_twi_errorsrc_get_and_clear(twi);
sahilmgandhi 18:6a4db94011d3 480
sahilmgandhi 18:6a4db94011d3 481 nrf_twi_shorts_set(twi, 0);
sahilmgandhi 18:6a4db94011d3 482
sahilmgandhi 18:6a4db94011d3 483 nrf_twi_address_set(twi, twi_address(address));
sahilmgandhi 18:6a4db94011d3 484 nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME);
sahilmgandhi 18:6a4db94011d3 485 nrf_twi_task_trigger(twi, NRF_TWI_TASK_STARTTX);
sahilmgandhi 18:6a4db94011d3 486 }
sahilmgandhi 18:6a4db94011d3 487
sahilmgandhi 18:6a4db94011d3 488 int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop)
sahilmgandhi 18:6a4db94011d3 489 {
sahilmgandhi 18:6a4db94011d3 490 twi_info_t *twi_info = TWI_INFO(obj);
sahilmgandhi 18:6a4db94011d3 491 #if DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 492 if (twi_info->active) {
sahilmgandhi 18:6a4db94011d3 493 return I2C_ERROR_BUS_BUSY;
sahilmgandhi 18:6a4db94011d3 494 }
sahilmgandhi 18:6a4db94011d3 495 #endif
sahilmgandhi 18:6a4db94011d3 496 twi_info->start_twi = false;
sahilmgandhi 18:6a4db94011d3 497
sahilmgandhi 18:6a4db94011d3 498 NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)];
sahilmgandhi 18:6a4db94011d3 499 start_twi_write(twi, address);
sahilmgandhi 18:6a4db94011d3 500
sahilmgandhi 18:6a4db94011d3 501 // Special case - transaction with no data.
sahilmgandhi 18:6a4db94011d3 502 // It can be used to check if a slave acknowledges the address.
sahilmgandhi 18:6a4db94011d3 503 if (length == 0) {
sahilmgandhi 18:6a4db94011d3 504 nrf_twi_event_t event;
sahilmgandhi 18:6a4db94011d3 505 if (stop) {
sahilmgandhi 18:6a4db94011d3 506 event = NRF_TWI_EVENT_STOPPED;
sahilmgandhi 18:6a4db94011d3 507 nrf_twi_task_trigger(twi, NRF_TWI_TASK_STOP);
sahilmgandhi 18:6a4db94011d3 508 } else {
sahilmgandhi 18:6a4db94011d3 509 event = NRF_TWI_EVENT_SUSPENDED;
sahilmgandhi 18:6a4db94011d3 510 nrf_twi_event_clear(twi, event);
sahilmgandhi 18:6a4db94011d3 511 nrf_twi_task_trigger(twi, NRF_TWI_TASK_SUSPEND);
sahilmgandhi 18:6a4db94011d3 512 }
sahilmgandhi 18:6a4db94011d3 513 uint32_t remaining_time = TIMEOUT_VALUE;
sahilmgandhi 18:6a4db94011d3 514 do {
sahilmgandhi 18:6a4db94011d3 515 if (nrf_twi_event_check(twi, event)) {
sahilmgandhi 18:6a4db94011d3 516 break;
sahilmgandhi 18:6a4db94011d3 517 }
sahilmgandhi 18:6a4db94011d3 518 } while (--remaining_time);
sahilmgandhi 18:6a4db94011d3 519
sahilmgandhi 18:6a4db94011d3 520 uint32_t errorsrc = nrf_twi_errorsrc_get_and_clear(twi);
sahilmgandhi 18:6a4db94011d3 521 if (errorsrc & NRF_TWI_ERROR_ADDRESS_NACK) {
sahilmgandhi 18:6a4db94011d3 522 if (!stop) {
sahilmgandhi 18:6a4db94011d3 523 i2c_stop(obj);
sahilmgandhi 18:6a4db94011d3 524 }
sahilmgandhi 18:6a4db94011d3 525 return I2C_ERROR_NO_SLAVE;
sahilmgandhi 18:6a4db94011d3 526 }
sahilmgandhi 18:6a4db94011d3 527
sahilmgandhi 18:6a4db94011d3 528 return (remaining_time ? 0 : I2C_ERROR_BUS_BUSY);
sahilmgandhi 18:6a4db94011d3 529 }
sahilmgandhi 18:6a4db94011d3 530
sahilmgandhi 18:6a4db94011d3 531 int result = length;
sahilmgandhi 18:6a4db94011d3 532 do {
sahilmgandhi 18:6a4db94011d3 533 uint8_t byte_write_result = twi_byte_write(twi, (uint8_t)*data++);
sahilmgandhi 18:6a4db94011d3 534 if (byte_write_result != 1) {
sahilmgandhi 18:6a4db94011d3 535 if (byte_write_result == 0) {
sahilmgandhi 18:6a4db94011d3 536 // Check what kind of error has been signaled by TWI.
sahilmgandhi 18:6a4db94011d3 537 uint32_t errorsrc = nrf_twi_errorsrc_get_and_clear(twi);
sahilmgandhi 18:6a4db94011d3 538 if (errorsrc & NRF_TWI_ERROR_ADDRESS_NACK) {
sahilmgandhi 18:6a4db94011d3 539 result = I2C_ERROR_NO_SLAVE;
sahilmgandhi 18:6a4db94011d3 540 } else {
sahilmgandhi 18:6a4db94011d3 541 // Some other error - return the number of bytes that
sahilmgandhi 18:6a4db94011d3 542 // have been sent successfully.
sahilmgandhi 18:6a4db94011d3 543 result -= length;
sahilmgandhi 18:6a4db94011d3 544 }
sahilmgandhi 18:6a4db94011d3 545 } else {
sahilmgandhi 18:6a4db94011d3 546 result = I2C_ERROR_BUS_BUSY;
sahilmgandhi 18:6a4db94011d3 547 }
sahilmgandhi 18:6a4db94011d3 548 // Force STOP condition.
sahilmgandhi 18:6a4db94011d3 549 stop = 1;
sahilmgandhi 18:6a4db94011d3 550 break;
sahilmgandhi 18:6a4db94011d3 551 }
sahilmgandhi 18:6a4db94011d3 552 --length;
sahilmgandhi 18:6a4db94011d3 553 } while (length > 0);
sahilmgandhi 18:6a4db94011d3 554
sahilmgandhi 18:6a4db94011d3 555 if (stop) {
sahilmgandhi 18:6a4db94011d3 556 (void)i2c_stop(obj);
sahilmgandhi 18:6a4db94011d3 557 }
sahilmgandhi 18:6a4db94011d3 558
sahilmgandhi 18:6a4db94011d3 559 return result;
sahilmgandhi 18:6a4db94011d3 560 }
sahilmgandhi 18:6a4db94011d3 561
sahilmgandhi 18:6a4db94011d3 562 int i2c_byte_read(i2c_t *obj, int last)
sahilmgandhi 18:6a4db94011d3 563 {
sahilmgandhi 18:6a4db94011d3 564 NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)];
sahilmgandhi 18:6a4db94011d3 565
sahilmgandhi 18:6a4db94011d3 566 if (last) {
sahilmgandhi 18:6a4db94011d3 567 nrf_twi_shorts_set(twi, NRF_TWI_SHORT_BB_STOP_MASK);
sahilmgandhi 18:6a4db94011d3 568 }
sahilmgandhi 18:6a4db94011d3 569 nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME);
sahilmgandhi 18:6a4db94011d3 570
sahilmgandhi 18:6a4db94011d3 571 uint32_t remaining_time = TIMEOUT_VALUE;
sahilmgandhi 18:6a4db94011d3 572 do {
sahilmgandhi 18:6a4db94011d3 573 if (nrf_twi_event_check(twi, NRF_TWI_EVENT_RXDREADY)) {
sahilmgandhi 18:6a4db94011d3 574 nrf_twi_event_clear(twi, NRF_TWI_EVENT_RXDREADY);
sahilmgandhi 18:6a4db94011d3 575 return nrf_twi_rxd_get(twi);
sahilmgandhi 18:6a4db94011d3 576 }
sahilmgandhi 18:6a4db94011d3 577 if (nrf_twi_event_check(twi, NRF_TWI_EVENT_ERROR)) {
sahilmgandhi 18:6a4db94011d3 578 nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR);
sahilmgandhi 18:6a4db94011d3 579 return I2C_ERROR_NO_SLAVE;
sahilmgandhi 18:6a4db94011d3 580 }
sahilmgandhi 18:6a4db94011d3 581 } while (--remaining_time);
sahilmgandhi 18:6a4db94011d3 582
sahilmgandhi 18:6a4db94011d3 583 return I2C_ERROR_BUS_BUSY;
sahilmgandhi 18:6a4db94011d3 584 }
sahilmgandhi 18:6a4db94011d3 585
sahilmgandhi 18:6a4db94011d3 586 int i2c_byte_write(i2c_t *obj, int data)
sahilmgandhi 18:6a4db94011d3 587 {
sahilmgandhi 18:6a4db94011d3 588 NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)];
sahilmgandhi 18:6a4db94011d3 589 twi_info_t *twi_info = TWI_INFO(obj);
sahilmgandhi 18:6a4db94011d3 590 if (twi_info->start_twi) {
sahilmgandhi 18:6a4db94011d3 591 twi_info->start_twi = false;
sahilmgandhi 18:6a4db94011d3 592
sahilmgandhi 18:6a4db94011d3 593 if (data & 1) {
sahilmgandhi 18:6a4db94011d3 594 start_twi_read(twi, data);
sahilmgandhi 18:6a4db94011d3 595 } else {
sahilmgandhi 18:6a4db94011d3 596 start_twi_write(twi, data);
sahilmgandhi 18:6a4db94011d3 597 }
sahilmgandhi 18:6a4db94011d3 598 return 1;
sahilmgandhi 18:6a4db94011d3 599 } else {
sahilmgandhi 18:6a4db94011d3 600 nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME);
sahilmgandhi 18:6a4db94011d3 601 // 0 - TWI signaled error (NAK is the only possibility here)
sahilmgandhi 18:6a4db94011d3 602 // 1 - ACK received
sahilmgandhi 18:6a4db94011d3 603 // 2 - timeout (clock stretched for too long?)
sahilmgandhi 18:6a4db94011d3 604 return twi_byte_write(twi, (uint8_t)data);
sahilmgandhi 18:6a4db94011d3 605 }
sahilmgandhi 18:6a4db94011d3 606 }
sahilmgandhi 18:6a4db94011d3 607
sahilmgandhi 18:6a4db94011d3 608
sahilmgandhi 18:6a4db94011d3 609 #if DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 610 void i2c_transfer_asynch(i2c_t *obj, const void *tx, size_t tx_length,
sahilmgandhi 18:6a4db94011d3 611 void *rx, size_t rx_length, uint32_t address,
sahilmgandhi 18:6a4db94011d3 612 uint32_t stop, uint32_t handler,
sahilmgandhi 18:6a4db94011d3 613 uint32_t event, DMAUsage hint)
sahilmgandhi 18:6a4db94011d3 614 {
sahilmgandhi 18:6a4db94011d3 615 (void)hint;
sahilmgandhi 18:6a4db94011d3 616
sahilmgandhi 18:6a4db94011d3 617 twi_info_t *twi_info = TWI_INFO(obj);
sahilmgandhi 18:6a4db94011d3 618 if (twi_info->active) {
sahilmgandhi 18:6a4db94011d3 619 return;
sahilmgandhi 18:6a4db94011d3 620 }
sahilmgandhi 18:6a4db94011d3 621 twi_info->active = true;
sahilmgandhi 18:6a4db94011d3 622 twi_info->events = 0;
sahilmgandhi 18:6a4db94011d3 623 twi_info->handler = (void (*)(void))handler;
sahilmgandhi 18:6a4db94011d3 624 twi_info->evt_mask = event;
sahilmgandhi 18:6a4db94011d3 625 twi_info->tx_length = tx_length;
sahilmgandhi 18:6a4db94011d3 626 twi_info->tx = tx;
sahilmgandhi 18:6a4db94011d3 627 twi_info->rx_length = rx_length;
sahilmgandhi 18:6a4db94011d3 628 twi_info->rx = rx;
sahilmgandhi 18:6a4db94011d3 629 twi_info->stop = stop;
sahilmgandhi 18:6a4db94011d3 630
sahilmgandhi 18:6a4db94011d3 631 NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)];
sahilmgandhi 18:6a4db94011d3 632
sahilmgandhi 18:6a4db94011d3 633 nrf_twi_event_clear(twi, NRF_TWI_EVENT_TXDSENT);
sahilmgandhi 18:6a4db94011d3 634 nrf_twi_event_clear(twi, NRF_TWI_EVENT_RXDREADY);
sahilmgandhi 18:6a4db94011d3 635 nrf_twi_event_clear(twi, NRF_TWI_EVENT_STOPPED);
sahilmgandhi 18:6a4db94011d3 636 nrf_twi_event_clear(twi, NRF_TWI_EVENT_SUSPENDED);
sahilmgandhi 18:6a4db94011d3 637 nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR);
sahilmgandhi 18:6a4db94011d3 638 (void)nrf_twi_errorsrc_get_and_clear(twi);
sahilmgandhi 18:6a4db94011d3 639
sahilmgandhi 18:6a4db94011d3 640 nrf_twi_address_set(twi, twi_address(address));
sahilmgandhi 18:6a4db94011d3 641 nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME);
sahilmgandhi 18:6a4db94011d3 642 // TX only, or TX + RX (after a repeated start).
sahilmgandhi 18:6a4db94011d3 643 if (tx_length > 0) {
sahilmgandhi 18:6a4db94011d3 644 nrf_twi_task_trigger(twi, NRF_TWI_TASK_STARTTX);
sahilmgandhi 18:6a4db94011d3 645 nrf_twi_txd_set(twi, *(twi_info->tx));
sahilmgandhi 18:6a4db94011d3 646 ++(twi_info->tx);
sahilmgandhi 18:6a4db94011d3 647 // RX only.
sahilmgandhi 18:6a4db94011d3 648 } else if (rx_length > 0) {
sahilmgandhi 18:6a4db94011d3 649 start_asynch_rx(twi_info, twi);
sahilmgandhi 18:6a4db94011d3 650 // Both 'tx_length' and 'rx_length' are 0 - this case may be used
sahilmgandhi 18:6a4db94011d3 651 // to test if the slave is presentand ready for transfer (by just
sahilmgandhi 18:6a4db94011d3 652 // sending the address and checking if it is acknowledged).
sahilmgandhi 18:6a4db94011d3 653 } else {
sahilmgandhi 18:6a4db94011d3 654 nrf_twi_task_trigger(twi, NRF_TWI_TASK_STARTTX);
sahilmgandhi 18:6a4db94011d3 655 if (stop) {
sahilmgandhi 18:6a4db94011d3 656 nrf_twi_task_trigger(twi, NRF_TWI_TASK_STOP);
sahilmgandhi 18:6a4db94011d3 657 } else {
sahilmgandhi 18:6a4db94011d3 658 nrf_twi_task_trigger(twi, NRF_TWI_TASK_SUSPEND);
sahilmgandhi 18:6a4db94011d3 659 nrf_twi_int_enable(twi, NRF_TWI_INT_SUSPENDED_MASK);
sahilmgandhi 18:6a4db94011d3 660 }
sahilmgandhi 18:6a4db94011d3 661 twi_info->events |= I2C_EVENT_TRANSFER_COMPLETE;
sahilmgandhi 18:6a4db94011d3 662 }
sahilmgandhi 18:6a4db94011d3 663
sahilmgandhi 18:6a4db94011d3 664 nrf_twi_int_enable(twi, NRF_TWI_INT_TXDSENT_MASK |
sahilmgandhi 18:6a4db94011d3 665 NRF_TWI_INT_RXDREADY_MASK |
sahilmgandhi 18:6a4db94011d3 666 NRF_TWI_INT_STOPPED_MASK |
sahilmgandhi 18:6a4db94011d3 667 NRF_TWI_INT_ERROR_MASK);
sahilmgandhi 18:6a4db94011d3 668 }
sahilmgandhi 18:6a4db94011d3 669
sahilmgandhi 18:6a4db94011d3 670 uint32_t i2c_irq_handler_asynch(i2c_t *obj)
sahilmgandhi 18:6a4db94011d3 671 {
sahilmgandhi 18:6a4db94011d3 672 twi_info_t *twi_info = TWI_INFO(obj);
sahilmgandhi 18:6a4db94011d3 673 return (twi_info->events & twi_info->evt_mask);
sahilmgandhi 18:6a4db94011d3 674 }
sahilmgandhi 18:6a4db94011d3 675
sahilmgandhi 18:6a4db94011d3 676 uint8_t i2c_active(i2c_t *obj)
sahilmgandhi 18:6a4db94011d3 677 {
sahilmgandhi 18:6a4db94011d3 678 twi_info_t *twi_info = TWI_INFO(obj);
sahilmgandhi 18:6a4db94011d3 679 return twi_info->active;
sahilmgandhi 18:6a4db94011d3 680 }
sahilmgandhi 18:6a4db94011d3 681
sahilmgandhi 18:6a4db94011d3 682 void i2c_abort_asynch(i2c_t *obj)
sahilmgandhi 18:6a4db94011d3 683 {
sahilmgandhi 18:6a4db94011d3 684 i2c_reset(obj);
sahilmgandhi 18:6a4db94011d3 685 }
sahilmgandhi 18:6a4db94011d3 686 #endif // DEVICE_I2C_ASYNCH
sahilmgandhi 18:6a4db94011d3 687
sahilmgandhi 18:6a4db94011d3 688 #endif // DEVICE_I2C