added prescaler for 16 bit pwm in LPC1347 target
Fork of mbed-dev by
targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/emlib/src/em_i2c.c@50:a417edff4437, 2016-01-15 (annotated)
- Committer:
- mbed_official
- Date:
- Fri Jan 15 07:45:16 2016 +0000
- Revision:
- 50:a417edff4437
- Parent:
- 0:9b334a45a8ff
- Child:
- 144:ef7eb2e8f9f7
Synchronized with git revision 6010f32619bfcbb01cc73747d4ff9040863482d9
Full URL: https://github.com/mbedmicro/mbed/commit/6010f32619bfcbb01cc73747d4ff9040863482d9/
Remove doubling of buffer size in realiseEndpoint()
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
bogdanm | 0:9b334a45a8ff | 1 | /***************************************************************************//** |
bogdanm | 0:9b334a45a8ff | 2 | * @file em_i2c.c |
bogdanm | 0:9b334a45a8ff | 3 | * @brief Inter-integrated Circuit (I2C) Peripheral API |
mbed_official | 50:a417edff4437 | 4 | * @version 4.2.1 |
bogdanm | 0:9b334a45a8ff | 5 | ******************************************************************************* |
bogdanm | 0:9b334a45a8ff | 6 | * @section License |
mbed_official | 50:a417edff4437 | 7 | * <b>(C) Copyright 2015 Silicon Labs, http://www.silabs.com</b> |
bogdanm | 0:9b334a45a8ff | 8 | ******************************************************************************* |
bogdanm | 0:9b334a45a8ff | 9 | * |
bogdanm | 0:9b334a45a8ff | 10 | * Permission is granted to anyone to use this software for any purpose, |
bogdanm | 0:9b334a45a8ff | 11 | * including commercial applications, and to alter it and redistribute it |
bogdanm | 0:9b334a45a8ff | 12 | * freely, subject to the following restrictions: |
bogdanm | 0:9b334a45a8ff | 13 | * |
bogdanm | 0:9b334a45a8ff | 14 | * 1. The origin of this software must not be misrepresented; you must not |
bogdanm | 0:9b334a45a8ff | 15 | * claim that you wrote the original software. |
bogdanm | 0:9b334a45a8ff | 16 | * 2. Altered source versions must be plainly marked as such, and must not be |
bogdanm | 0:9b334a45a8ff | 17 | * misrepresented as being the original software. |
bogdanm | 0:9b334a45a8ff | 18 | * 3. This notice may not be removed or altered from any source distribution. |
bogdanm | 0:9b334a45a8ff | 19 | * |
bogdanm | 0:9b334a45a8ff | 20 | * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no |
bogdanm | 0:9b334a45a8ff | 21 | * obligation to support this Software. Silicon Labs is providing the |
bogdanm | 0:9b334a45a8ff | 22 | * Software "AS IS", with no express or implied warranties of any kind, |
bogdanm | 0:9b334a45a8ff | 23 | * including, but not limited to, any implied warranties of merchantability |
bogdanm | 0:9b334a45a8ff | 24 | * or fitness for any particular purpose or warranties against infringement |
bogdanm | 0:9b334a45a8ff | 25 | * of any proprietary rights of a third party. |
bogdanm | 0:9b334a45a8ff | 26 | * |
bogdanm | 0:9b334a45a8ff | 27 | * Silicon Labs will not be liable for any consequential, incidental, or |
bogdanm | 0:9b334a45a8ff | 28 | * special damages, or any other relief, or for any claim by any third party, |
bogdanm | 0:9b334a45a8ff | 29 | * arising from your use of this Software. |
bogdanm | 0:9b334a45a8ff | 30 | * |
bogdanm | 0:9b334a45a8ff | 31 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 32 | |
bogdanm | 0:9b334a45a8ff | 33 | #include "em_i2c.h" |
bogdanm | 0:9b334a45a8ff | 34 | #if defined(I2C_COUNT) && (I2C_COUNT > 0) |
bogdanm | 0:9b334a45a8ff | 35 | |
bogdanm | 0:9b334a45a8ff | 36 | #include "em_cmu.h" |
mbed_official | 50:a417edff4437 | 37 | #include "em_bus.h" |
bogdanm | 0:9b334a45a8ff | 38 | #include "em_assert.h" |
bogdanm | 0:9b334a45a8ff | 39 | |
mbed_official | 50:a417edff4437 | 40 | #include <limits.h> |
mbed_official | 50:a417edff4437 | 41 | |
bogdanm | 0:9b334a45a8ff | 42 | /***************************************************************************//** |
bogdanm | 0:9b334a45a8ff | 43 | * @addtogroup EM_Library |
bogdanm | 0:9b334a45a8ff | 44 | * @{ |
bogdanm | 0:9b334a45a8ff | 45 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 46 | |
bogdanm | 0:9b334a45a8ff | 47 | /***************************************************************************//** |
bogdanm | 0:9b334a45a8ff | 48 | * @addtogroup I2C |
bogdanm | 0:9b334a45a8ff | 49 | * @brief Inter-integrated Circuit (I2C) Peripheral API |
bogdanm | 0:9b334a45a8ff | 50 | * @{ |
bogdanm | 0:9b334a45a8ff | 51 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 52 | |
bogdanm | 0:9b334a45a8ff | 53 | /******************************************************************************* |
bogdanm | 0:9b334a45a8ff | 54 | ******************************* DEFINES *********************************** |
bogdanm | 0:9b334a45a8ff | 55 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 56 | |
bogdanm | 0:9b334a45a8ff | 57 | /** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */ |
bogdanm | 0:9b334a45a8ff | 58 | |
mbed_official | 50:a417edff4437 | 59 | /** Validation of I2C register block pointer reference for assert statements. */ |
bogdanm | 0:9b334a45a8ff | 60 | #if (I2C_COUNT == 1) |
bogdanm | 0:9b334a45a8ff | 61 | #define I2C_REF_VALID(ref) ((ref) == I2C0) |
bogdanm | 0:9b334a45a8ff | 62 | #elif (I2C_COUNT == 2) |
bogdanm | 0:9b334a45a8ff | 63 | #define I2C_REF_VALID(ref) ((ref == I2C0) || (ref == I2C1)) |
mbed_official | 50:a417edff4437 | 64 | #elif (I2C_COUNT == 3) |
mbed_official | 50:a417edff4437 | 65 | #define I2C_REF_VALID(ref) ((ref == I2C0) || (ref == I2C1)|| (ref == I2C2)) |
bogdanm | 0:9b334a45a8ff | 66 | #endif |
bogdanm | 0:9b334a45a8ff | 67 | |
bogdanm | 0:9b334a45a8ff | 68 | /** Error flags indicating I2C transfer has failed somehow. */ |
bogdanm | 0:9b334a45a8ff | 69 | /* Notice that I2C_IF_TXOF (transmit overflow) is not really possible with */ |
bogdanm | 0:9b334a45a8ff | 70 | /* this SW supporting master mode. Likewise for I2C_IF_RXUF (receive underflow) */ |
bogdanm | 0:9b334a45a8ff | 71 | /* RXUF is only likely to occur with this SW if using a debugger peeking into */ |
bogdanm | 0:9b334a45a8ff | 72 | /* RXDATA register. Thus, we ignore those types of fault. */ |
bogdanm | 0:9b334a45a8ff | 73 | #define I2C_IF_ERRORS (I2C_IF_BUSERR | I2C_IF_ARBLOST) |
bogdanm | 0:9b334a45a8ff | 74 | |
mbed_official | 50:a417edff4437 | 75 | /* Max I2C transmission rate constant */ |
mbed_official | 50:a417edff4437 | 76 | #if defined( _SILICON_LABS_32B_PLATFORM_1 ) |
mbed_official | 50:a417edff4437 | 77 | #define I2C_CR_MAX 4 |
mbed_official | 50:a417edff4437 | 78 | #elif defined( _SILICON_LABS_32B_PLATFORM_2 ) |
mbed_official | 50:a417edff4437 | 79 | #define I2C_CR_MAX 8 |
mbed_official | 50:a417edff4437 | 80 | #else |
mbed_official | 50:a417edff4437 | 81 | #warning "Max I2C transmission rate constant is not defined" |
mbed_official | 50:a417edff4437 | 82 | #endif |
mbed_official | 50:a417edff4437 | 83 | |
bogdanm | 0:9b334a45a8ff | 84 | /** @endcond */ |
bogdanm | 0:9b334a45a8ff | 85 | |
bogdanm | 0:9b334a45a8ff | 86 | /******************************************************************************* |
bogdanm | 0:9b334a45a8ff | 87 | ******************************** ENUMS ************************************ |
bogdanm | 0:9b334a45a8ff | 88 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 89 | |
bogdanm | 0:9b334a45a8ff | 90 | /** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */ |
bogdanm | 0:9b334a45a8ff | 91 | |
bogdanm | 0:9b334a45a8ff | 92 | /** Master mode transfer states. */ |
bogdanm | 0:9b334a45a8ff | 93 | typedef enum |
bogdanm | 0:9b334a45a8ff | 94 | { |
bogdanm | 0:9b334a45a8ff | 95 | i2cStateStartAddrSend, /**< Send start + (first part of) address. */ |
bogdanm | 0:9b334a45a8ff | 96 | i2cStateAddrWFAckNack, /**< Wait for ACK/NACK on (first part of) address. */ |
bogdanm | 0:9b334a45a8ff | 97 | i2cStateAddrWF2ndAckNack, /**< Wait for ACK/NACK on second part of 10 bit address. */ |
bogdanm | 0:9b334a45a8ff | 98 | i2cStateRStartAddrSend, /**< Send repeated start + (first part of) address. */ |
bogdanm | 0:9b334a45a8ff | 99 | i2cStateRAddrWFAckNack, /**< Wait for ACK/NACK on address sent after repeated start. */ |
bogdanm | 0:9b334a45a8ff | 100 | i2cStateDataSend, /**< Send data. */ |
bogdanm | 0:9b334a45a8ff | 101 | i2cStateDataWFAckNack, /**< Wait for ACK/NACK on data sent. */ |
bogdanm | 0:9b334a45a8ff | 102 | i2cStateWFData, /**< Wait for data. */ |
bogdanm | 0:9b334a45a8ff | 103 | i2cStateWFStopSent, /**< Wait for STOP to have been transmitted. */ |
bogdanm | 0:9b334a45a8ff | 104 | i2cStateDone /**< Transfer completed successfully. */ |
bogdanm | 0:9b334a45a8ff | 105 | } I2C_TransferState_TypeDef; |
bogdanm | 0:9b334a45a8ff | 106 | |
bogdanm | 0:9b334a45a8ff | 107 | /** @endcond */ |
bogdanm | 0:9b334a45a8ff | 108 | |
bogdanm | 0:9b334a45a8ff | 109 | /******************************************************************************* |
bogdanm | 0:9b334a45a8ff | 110 | ******************************* STRUCTS *********************************** |
bogdanm | 0:9b334a45a8ff | 111 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 112 | |
bogdanm | 0:9b334a45a8ff | 113 | /** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */ |
bogdanm | 0:9b334a45a8ff | 114 | |
bogdanm | 0:9b334a45a8ff | 115 | /** Structure used to store state information on an ongoing master mode transfer. */ |
bogdanm | 0:9b334a45a8ff | 116 | typedef struct |
bogdanm | 0:9b334a45a8ff | 117 | { |
bogdanm | 0:9b334a45a8ff | 118 | /** Current state. */ |
bogdanm | 0:9b334a45a8ff | 119 | I2C_TransferState_TypeDef state; |
bogdanm | 0:9b334a45a8ff | 120 | |
bogdanm | 0:9b334a45a8ff | 121 | /** Result return code. */ |
bogdanm | 0:9b334a45a8ff | 122 | I2C_TransferReturn_TypeDef result; |
bogdanm | 0:9b334a45a8ff | 123 | |
bogdanm | 0:9b334a45a8ff | 124 | /** Offset in current sequence buffer. */ |
bogdanm | 0:9b334a45a8ff | 125 | uint16_t offset; |
bogdanm | 0:9b334a45a8ff | 126 | |
bogdanm | 0:9b334a45a8ff | 127 | /* Index to current sequence buffer in use. */ |
bogdanm | 0:9b334a45a8ff | 128 | uint8_t bufIndx; |
bogdanm | 0:9b334a45a8ff | 129 | |
bogdanm | 0:9b334a45a8ff | 130 | /** Reference to I2C transfer sequence definition provided by user. */ |
bogdanm | 0:9b334a45a8ff | 131 | I2C_TransferSeq_TypeDef *seq; |
bogdanm | 0:9b334a45a8ff | 132 | } I2C_Transfer_TypeDef; |
bogdanm | 0:9b334a45a8ff | 133 | |
bogdanm | 0:9b334a45a8ff | 134 | /** @endcond */ |
bogdanm | 0:9b334a45a8ff | 135 | |
bogdanm | 0:9b334a45a8ff | 136 | /******************************************************************************* |
bogdanm | 0:9b334a45a8ff | 137 | ***************************** LOCAL DATA *******^************************** |
bogdanm | 0:9b334a45a8ff | 138 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 139 | |
bogdanm | 0:9b334a45a8ff | 140 | /** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */ |
bogdanm | 0:9b334a45a8ff | 141 | |
bogdanm | 0:9b334a45a8ff | 142 | /** |
bogdanm | 0:9b334a45a8ff | 143 | * Lookup table for Nlow + Nhigh setting defined by CLHR. Set undefined |
bogdanm | 0:9b334a45a8ff | 144 | * index (0x3) to reflect default setting just in case. |
bogdanm | 0:9b334a45a8ff | 145 | */ |
bogdanm | 0:9b334a45a8ff | 146 | static const uint8_t i2cNSum[] = { 4 + 4, 6 + 3, 11 + 6, 4 + 4 }; |
bogdanm | 0:9b334a45a8ff | 147 | |
bogdanm | 0:9b334a45a8ff | 148 | /** Transfer state info for ongoing master mode transfer */ |
bogdanm | 0:9b334a45a8ff | 149 | static I2C_Transfer_TypeDef i2cTransfer[I2C_COUNT]; |
bogdanm | 0:9b334a45a8ff | 150 | |
bogdanm | 0:9b334a45a8ff | 151 | /** @endcond */ |
bogdanm | 0:9b334a45a8ff | 152 | |
bogdanm | 0:9b334a45a8ff | 153 | /******************************************************************************* |
bogdanm | 0:9b334a45a8ff | 154 | ************************** GLOBAL FUNCTIONS ******************************* |
bogdanm | 0:9b334a45a8ff | 155 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 156 | |
bogdanm | 0:9b334a45a8ff | 157 | /***************************************************************************//** |
bogdanm | 0:9b334a45a8ff | 158 | * @brief |
bogdanm | 0:9b334a45a8ff | 159 | * Get current configured I2C bus frequency. |
bogdanm | 0:9b334a45a8ff | 160 | * |
bogdanm | 0:9b334a45a8ff | 161 | * @details |
bogdanm | 0:9b334a45a8ff | 162 | * This frequency is only of relevance when acting as master. |
bogdanm | 0:9b334a45a8ff | 163 | * |
bogdanm | 0:9b334a45a8ff | 164 | * @param[in] i2c |
bogdanm | 0:9b334a45a8ff | 165 | * Pointer to I2C peripheral register block. |
bogdanm | 0:9b334a45a8ff | 166 | * |
bogdanm | 0:9b334a45a8ff | 167 | * @return |
bogdanm | 0:9b334a45a8ff | 168 | * Current I2C frequency in Hz. |
bogdanm | 0:9b334a45a8ff | 169 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 170 | uint32_t I2C_BusFreqGet(I2C_TypeDef *i2c) |
bogdanm | 0:9b334a45a8ff | 171 | { |
mbed_official | 50:a417edff4437 | 172 | uint32_t freqHfper; |
bogdanm | 0:9b334a45a8ff | 173 | uint32_t n; |
bogdanm | 0:9b334a45a8ff | 174 | |
mbed_official | 50:a417edff4437 | 175 | /* Max frequency is given by freqScl = freqHfper/((Nlow + Nhigh)(DIV + 1) + I2C_CR_MAX) |
mbed_official | 50:a417edff4437 | 176 | * More details can be found in the reference manual, |
mbed_official | 50:a417edff4437 | 177 | * I2C Clock Generation chapter. */ |
mbed_official | 50:a417edff4437 | 178 | freqHfper = CMU_ClockFreqGet(cmuClock_HFPER); |
mbed_official | 50:a417edff4437 | 179 | /* n = Nlow + Nhigh */ |
bogdanm | 0:9b334a45a8ff | 180 | n = (uint32_t)(i2cNSum[(i2c->CTRL & _I2C_CTRL_CLHR_MASK) >> _I2C_CTRL_CLHR_SHIFT]); |
bogdanm | 0:9b334a45a8ff | 181 | |
mbed_official | 50:a417edff4437 | 182 | return (freqHfper / ((n * (i2c->CLKDIV + 1)) + I2C_CR_MAX)); |
bogdanm | 0:9b334a45a8ff | 183 | } |
bogdanm | 0:9b334a45a8ff | 184 | |
bogdanm | 0:9b334a45a8ff | 185 | |
bogdanm | 0:9b334a45a8ff | 186 | /***************************************************************************//** |
bogdanm | 0:9b334a45a8ff | 187 | * @brief |
bogdanm | 0:9b334a45a8ff | 188 | * Set I2C bus frequency. |
bogdanm | 0:9b334a45a8ff | 189 | * |
bogdanm | 0:9b334a45a8ff | 190 | * @details |
bogdanm | 0:9b334a45a8ff | 191 | * The bus frequency is only of relevance when acting as a master. The bus |
bogdanm | 0:9b334a45a8ff | 192 | * frequency should not be set higher than the max frequency accepted by the |
bogdanm | 0:9b334a45a8ff | 193 | * slowest device on the bus. |
bogdanm | 0:9b334a45a8ff | 194 | * |
bogdanm | 0:9b334a45a8ff | 195 | * Notice that due to asymmetric requirements on low and high I2C clock |
bogdanm | 0:9b334a45a8ff | 196 | * cycles by the I2C specification, the actual max frequency allowed in order |
bogdanm | 0:9b334a45a8ff | 197 | * to comply with the specification may be somewhat lower than expected. |
bogdanm | 0:9b334a45a8ff | 198 | * |
bogdanm | 0:9b334a45a8ff | 199 | * Please refer to the reference manual, details on I2C clock generation, |
bogdanm | 0:9b334a45a8ff | 200 | * for max allowed theoretical frequencies for different modes. |
bogdanm | 0:9b334a45a8ff | 201 | * |
bogdanm | 0:9b334a45a8ff | 202 | * @param[in] i2c |
bogdanm | 0:9b334a45a8ff | 203 | * Pointer to I2C peripheral register block. |
bogdanm | 0:9b334a45a8ff | 204 | * |
mbed_official | 50:a417edff4437 | 205 | * @param[in] freqRef |
bogdanm | 0:9b334a45a8ff | 206 | * I2C reference clock frequency in Hz that will be used. If set to 0, |
mbed_official | 50:a417edff4437 | 207 | * then HFPER clock is used. Setting it to a higher than actual configured |
mbed_official | 50:a417edff4437 | 208 | * value only has the consequence of reducing the real I2C frequency. |
bogdanm | 0:9b334a45a8ff | 209 | * |
mbed_official | 50:a417edff4437 | 210 | * @param[in] freqScl |
bogdanm | 0:9b334a45a8ff | 211 | * Bus frequency to set (actual bus speed may be lower due to integer |
bogdanm | 0:9b334a45a8ff | 212 | * prescaling). Safe (according to I2C specification) max frequencies for |
bogdanm | 0:9b334a45a8ff | 213 | * standard, fast and fast+ modes are available using I2C_FREQ_ defines. |
bogdanm | 0:9b334a45a8ff | 214 | * (Using I2C_FREQ_ defines requires corresponding setting of @p type.) |
bogdanm | 0:9b334a45a8ff | 215 | * Slowest slave device on bus must always be considered. |
bogdanm | 0:9b334a45a8ff | 216 | * |
mbed_official | 50:a417edff4437 | 217 | * @param[in] i2cMode |
bogdanm | 0:9b334a45a8ff | 218 | * Clock low to high ratio type to use. If not using i2cClockHLRStandard, |
bogdanm | 0:9b334a45a8ff | 219 | * make sure all devices on the bus support the specified mode. Using a |
bogdanm | 0:9b334a45a8ff | 220 | * non-standard ratio is useful to achieve higher bus clock in fast and |
bogdanm | 0:9b334a45a8ff | 221 | * fast+ modes. |
bogdanm | 0:9b334a45a8ff | 222 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 223 | void I2C_BusFreqSet(I2C_TypeDef *i2c, |
mbed_official | 50:a417edff4437 | 224 | uint32_t freqRef, |
mbed_official | 50:a417edff4437 | 225 | uint32_t freqScl, |
mbed_official | 50:a417edff4437 | 226 | I2C_ClockHLR_TypeDef i2cMode) |
bogdanm | 0:9b334a45a8ff | 227 | { |
mbed_official | 50:a417edff4437 | 228 | uint32_t n, minFreq; |
mbed_official | 50:a417edff4437 | 229 | int32_t div; |
bogdanm | 0:9b334a45a8ff | 230 | |
bogdanm | 0:9b334a45a8ff | 231 | /* Avoid divide by 0 */ |
mbed_official | 50:a417edff4437 | 232 | EFM_ASSERT(freqScl); |
mbed_official | 50:a417edff4437 | 233 | if (!freqScl) |
bogdanm | 0:9b334a45a8ff | 234 | { |
bogdanm | 0:9b334a45a8ff | 235 | return; |
bogdanm | 0:9b334a45a8ff | 236 | } |
bogdanm | 0:9b334a45a8ff | 237 | |
bogdanm | 0:9b334a45a8ff | 238 | /* Set the CLHR (clock low to high ratio). */ |
bogdanm | 0:9b334a45a8ff | 239 | i2c->CTRL &= ~_I2C_CTRL_CLHR_MASK; |
mbed_official | 50:a417edff4437 | 240 | BUS_RegMaskedWrite(&i2c->CTRL, |
mbed_official | 50:a417edff4437 | 241 | _I2C_CTRL_CLHR_MASK, |
mbed_official | 50:a417edff4437 | 242 | i2cMode <<_I2C_CTRL_CLHR_SHIFT); |
bogdanm | 0:9b334a45a8ff | 243 | |
mbed_official | 50:a417edff4437 | 244 | if (!freqRef) |
mbed_official | 50:a417edff4437 | 245 | { |
mbed_official | 50:a417edff4437 | 246 | freqRef = CMU_ClockFreqGet(cmuClock_HFPER); |
mbed_official | 50:a417edff4437 | 247 | } |
bogdanm | 0:9b334a45a8ff | 248 | |
mbed_official | 50:a417edff4437 | 249 | /* Check minumum HF peripheral clock */ |
mbed_official | 50:a417edff4437 | 250 | minFreq = UINT_MAX; |
mbed_official | 50:a417edff4437 | 251 | if (i2c->CTRL & I2C_CTRL_SLAVE) |
bogdanm | 0:9b334a45a8ff | 252 | { |
mbed_official | 50:a417edff4437 | 253 | switch(i2cMode) |
mbed_official | 50:a417edff4437 | 254 | { |
mbed_official | 50:a417edff4437 | 255 | case i2cClockHLRStandard: |
mbed_official | 50:a417edff4437 | 256 | #if defined( _SILICON_LABS_32B_PLATFORM_1 ) |
mbed_official | 50:a417edff4437 | 257 | minFreq = 4200000; break; |
mbed_official | 50:a417edff4437 | 258 | #elif defined( _SILICON_LABS_32B_PLATFORM_2 ) |
mbed_official | 50:a417edff4437 | 259 | minFreq = 2000000; break; |
mbed_official | 50:a417edff4437 | 260 | #endif |
mbed_official | 50:a417edff4437 | 261 | case i2cClockHLRAsymetric: |
mbed_official | 50:a417edff4437 | 262 | #if defined( _SILICON_LABS_32B_PLATFORM_1 ) |
mbed_official | 50:a417edff4437 | 263 | minFreq = 11000000; break; |
mbed_official | 50:a417edff4437 | 264 | #elif defined( _SILICON_LABS_32B_PLATFORM_2 ) |
mbed_official | 50:a417edff4437 | 265 | minFreq = 5000000; break; |
mbed_official | 50:a417edff4437 | 266 | #endif |
mbed_official | 50:a417edff4437 | 267 | case i2cClockHLRFast: |
mbed_official | 50:a417edff4437 | 268 | #if defined( _SILICON_LABS_32B_PLATFORM_1 ) |
mbed_official | 50:a417edff4437 | 269 | minFreq = 24400000; break; |
mbed_official | 50:a417edff4437 | 270 | #elif defined( _SILICON_LABS_32B_PLATFORM_2 ) |
mbed_official | 50:a417edff4437 | 271 | minFreq = 14000000; break; |
mbed_official | 50:a417edff4437 | 272 | #endif |
mbed_official | 50:a417edff4437 | 273 | } |
bogdanm | 0:9b334a45a8ff | 274 | } |
mbed_official | 50:a417edff4437 | 275 | else |
mbed_official | 50:a417edff4437 | 276 | { |
mbed_official | 50:a417edff4437 | 277 | /* For master mode, platform 1 and 2 share the same |
mbed_official | 50:a417edff4437 | 278 | min frequencies */ |
mbed_official | 50:a417edff4437 | 279 | switch(i2cMode) |
mbed_official | 50:a417edff4437 | 280 | { |
mbed_official | 50:a417edff4437 | 281 | case i2cClockHLRStandard: |
mbed_official | 50:a417edff4437 | 282 | minFreq = 2000000; break; |
mbed_official | 50:a417edff4437 | 283 | case i2cClockHLRAsymetric: |
mbed_official | 50:a417edff4437 | 284 | minFreq = 9000000; break; |
mbed_official | 50:a417edff4437 | 285 | case i2cClockHLRFast: |
mbed_official | 50:a417edff4437 | 286 | minFreq = 20000000; break; |
mbed_official | 50:a417edff4437 | 287 | } |
mbed_official | 50:a417edff4437 | 288 | } |
bogdanm | 0:9b334a45a8ff | 289 | |
mbed_official | 50:a417edff4437 | 290 | /* Frequency most be larger-than */ |
mbed_official | 50:a417edff4437 | 291 | EFM_ASSERT(freqRef > minFreq); |
mbed_official | 50:a417edff4437 | 292 | |
mbed_official | 50:a417edff4437 | 293 | /* SCL frequency is given by |
mbed_official | 50:a417edff4437 | 294 | * freqScl = freqRef/((Nlow + Nhigh) * (DIV + 1) + I2C_C_MAX) |
mbed_official | 50:a417edff4437 | 295 | * |
mbed_official | 50:a417edff4437 | 296 | * Thus |
mbed_official | 50:a417edff4437 | 297 | * DIV = ((freqRef - (I2C_C_MAX * freqScl))/((Nlow + Nhigh) * freqScl)) - 1 |
mbed_official | 50:a417edff4437 | 298 | * |
mbed_official | 50:a417edff4437 | 299 | * More details can be found in the reference manual, |
mbed_official | 50:a417edff4437 | 300 | * I2C Clock Generation chapter. */ |
mbed_official | 50:a417edff4437 | 301 | |
mbed_official | 50:a417edff4437 | 302 | /* n = Nlow + Nhigh */ |
mbed_official | 50:a417edff4437 | 303 | n = (uint32_t)(i2cNSum[i2cMode]); |
mbed_official | 50:a417edff4437 | 304 | div = ((freqRef - (I2C_CR_MAX * freqScl)) / (n * freqScl)) - 1; |
mbed_official | 50:a417edff4437 | 305 | EFM_ASSERT(div >= 0); |
mbed_official | 50:a417edff4437 | 306 | EFM_ASSERT((uint32_t)div <= _I2C_CLKDIV_DIV_MASK); |
bogdanm | 0:9b334a45a8ff | 307 | |
bogdanm | 0:9b334a45a8ff | 308 | /* Clock divisor must be at least 1 in slave mode according to reference */ |
bogdanm | 0:9b334a45a8ff | 309 | /* manual (in which case there is normally no need to set bus frequency). */ |
bogdanm | 0:9b334a45a8ff | 310 | if ((i2c->CTRL & I2C_CTRL_SLAVE) && !div) |
bogdanm | 0:9b334a45a8ff | 311 | { |
bogdanm | 0:9b334a45a8ff | 312 | div = 1; |
bogdanm | 0:9b334a45a8ff | 313 | } |
mbed_official | 50:a417edff4437 | 314 | i2c->CLKDIV = (uint32_t)div; |
bogdanm | 0:9b334a45a8ff | 315 | } |
bogdanm | 0:9b334a45a8ff | 316 | |
bogdanm | 0:9b334a45a8ff | 317 | |
bogdanm | 0:9b334a45a8ff | 318 | /***************************************************************************//** |
bogdanm | 0:9b334a45a8ff | 319 | * @brief |
bogdanm | 0:9b334a45a8ff | 320 | * Enable/disable I2C. |
bogdanm | 0:9b334a45a8ff | 321 | * |
bogdanm | 0:9b334a45a8ff | 322 | * @note |
bogdanm | 0:9b334a45a8ff | 323 | * After enabling the I2C (from being disabled), the I2C is in BUSY state. |
bogdanm | 0:9b334a45a8ff | 324 | * |
bogdanm | 0:9b334a45a8ff | 325 | * @param[in] i2c |
bogdanm | 0:9b334a45a8ff | 326 | * Pointer to I2C peripheral register block. |
bogdanm | 0:9b334a45a8ff | 327 | * |
bogdanm | 0:9b334a45a8ff | 328 | * @param[in] enable |
bogdanm | 0:9b334a45a8ff | 329 | * true to enable counting, false to disable. |
bogdanm | 0:9b334a45a8ff | 330 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 331 | void I2C_Enable(I2C_TypeDef *i2c, bool enable) |
bogdanm | 0:9b334a45a8ff | 332 | { |
bogdanm | 0:9b334a45a8ff | 333 | EFM_ASSERT(I2C_REF_VALID(i2c)); |
bogdanm | 0:9b334a45a8ff | 334 | |
mbed_official | 50:a417edff4437 | 335 | BUS_RegBitWrite(&(i2c->CTRL), _I2C_CTRL_EN_SHIFT, enable); |
bogdanm | 0:9b334a45a8ff | 336 | } |
bogdanm | 0:9b334a45a8ff | 337 | |
bogdanm | 0:9b334a45a8ff | 338 | |
bogdanm | 0:9b334a45a8ff | 339 | /***************************************************************************//** |
bogdanm | 0:9b334a45a8ff | 340 | * @brief |
bogdanm | 0:9b334a45a8ff | 341 | * Initialize I2C. |
bogdanm | 0:9b334a45a8ff | 342 | * |
bogdanm | 0:9b334a45a8ff | 343 | * @param[in] i2c |
bogdanm | 0:9b334a45a8ff | 344 | * Pointer to I2C peripheral register block. |
bogdanm | 0:9b334a45a8ff | 345 | * |
bogdanm | 0:9b334a45a8ff | 346 | * @param[in] init |
bogdanm | 0:9b334a45a8ff | 347 | * Pointer to I2C initialization structure. |
bogdanm | 0:9b334a45a8ff | 348 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 349 | void I2C_Init(I2C_TypeDef *i2c, const I2C_Init_TypeDef *init) |
bogdanm | 0:9b334a45a8ff | 350 | { |
bogdanm | 0:9b334a45a8ff | 351 | EFM_ASSERT(I2C_REF_VALID(i2c)); |
bogdanm | 0:9b334a45a8ff | 352 | |
bogdanm | 0:9b334a45a8ff | 353 | i2c->IEN = 0; |
bogdanm | 0:9b334a45a8ff | 354 | i2c->IFC = _I2C_IFC_MASK; |
bogdanm | 0:9b334a45a8ff | 355 | |
bogdanm | 0:9b334a45a8ff | 356 | /* Set SLAVE select mode */ |
mbed_official | 50:a417edff4437 | 357 | BUS_RegBitWrite(&(i2c->CTRL), _I2C_CTRL_SLAVE_SHIFT, init->master ? 0 : 1); |
bogdanm | 0:9b334a45a8ff | 358 | |
bogdanm | 0:9b334a45a8ff | 359 | I2C_BusFreqSet(i2c, init->refFreq, init->freq, init->clhr); |
bogdanm | 0:9b334a45a8ff | 360 | |
mbed_official | 50:a417edff4437 | 361 | BUS_RegBitWrite(&(i2c->CTRL), _I2C_CTRL_EN_SHIFT, init->enable); |
bogdanm | 0:9b334a45a8ff | 362 | } |
bogdanm | 0:9b334a45a8ff | 363 | |
bogdanm | 0:9b334a45a8ff | 364 | |
bogdanm | 0:9b334a45a8ff | 365 | /***************************************************************************//** |
bogdanm | 0:9b334a45a8ff | 366 | * @brief |
bogdanm | 0:9b334a45a8ff | 367 | * Reset I2C to same state as after a HW reset. |
bogdanm | 0:9b334a45a8ff | 368 | * |
bogdanm | 0:9b334a45a8ff | 369 | * @note |
bogdanm | 0:9b334a45a8ff | 370 | * The ROUTE register is NOT reset by this function, in order to allow for |
bogdanm | 0:9b334a45a8ff | 371 | * centralized setup of this feature. |
bogdanm | 0:9b334a45a8ff | 372 | * |
bogdanm | 0:9b334a45a8ff | 373 | * @param[in] i2c |
bogdanm | 0:9b334a45a8ff | 374 | * Pointer to I2C peripheral register block. |
bogdanm | 0:9b334a45a8ff | 375 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 376 | void I2C_Reset(I2C_TypeDef *i2c) |
bogdanm | 0:9b334a45a8ff | 377 | { |
bogdanm | 0:9b334a45a8ff | 378 | i2c->CTRL = _I2C_CTRL_RESETVALUE; |
bogdanm | 0:9b334a45a8ff | 379 | i2c->CLKDIV = _I2C_CLKDIV_RESETVALUE; |
bogdanm | 0:9b334a45a8ff | 380 | i2c->SADDR = _I2C_SADDR_RESETVALUE; |
bogdanm | 0:9b334a45a8ff | 381 | i2c->SADDRMASK = _I2C_SADDRMASK_RESETVALUE; |
bogdanm | 0:9b334a45a8ff | 382 | i2c->IEN = _I2C_IEN_RESETVALUE; |
bogdanm | 0:9b334a45a8ff | 383 | i2c->IFC = _I2C_IFC_MASK; |
bogdanm | 0:9b334a45a8ff | 384 | /* Do not reset route register, setting should be done independently */ |
bogdanm | 0:9b334a45a8ff | 385 | } |
bogdanm | 0:9b334a45a8ff | 386 | |
bogdanm | 0:9b334a45a8ff | 387 | |
bogdanm | 0:9b334a45a8ff | 388 | /***************************************************************************//** |
bogdanm | 0:9b334a45a8ff | 389 | * @brief |
bogdanm | 0:9b334a45a8ff | 390 | * Continue an initiated I2C transfer (single master mode only). |
bogdanm | 0:9b334a45a8ff | 391 | * |
bogdanm | 0:9b334a45a8ff | 392 | * @details |
bogdanm | 0:9b334a45a8ff | 393 | * This function is used repeatedly after a I2C_TransferInit() in order to |
bogdanm | 0:9b334a45a8ff | 394 | * complete a transfer. It may be used in polled mode as the below example |
bogdanm | 0:9b334a45a8ff | 395 | * shows: |
bogdanm | 0:9b334a45a8ff | 396 | * @verbatim |
bogdanm | 0:9b334a45a8ff | 397 | * I2C_TransferReturn_TypeDef ret; |
bogdanm | 0:9b334a45a8ff | 398 | * |
bogdanm | 0:9b334a45a8ff | 399 | * // Do a polled transfer |
bogdanm | 0:9b334a45a8ff | 400 | * ret = I2C_TransferInit(I2C0, seq); |
bogdanm | 0:9b334a45a8ff | 401 | * while (ret == i2cTransferInProgress) |
bogdanm | 0:9b334a45a8ff | 402 | * { |
bogdanm | 0:9b334a45a8ff | 403 | * ret = I2C_Transfer(I2C0); |
bogdanm | 0:9b334a45a8ff | 404 | * } |
bogdanm | 0:9b334a45a8ff | 405 | * @endverbatim |
bogdanm | 0:9b334a45a8ff | 406 | * It may also be used in interrupt driven mode, where this function is invoked |
bogdanm | 0:9b334a45a8ff | 407 | * from the interrupt handler. Notice that if used in interrupt mode, NVIC |
bogdanm | 0:9b334a45a8ff | 408 | * interrupts must be configured and enabled for the I2C bus used. I2C |
bogdanm | 0:9b334a45a8ff | 409 | * peripheral specific interrupts are managed by this SW. |
bogdanm | 0:9b334a45a8ff | 410 | * |
bogdanm | 0:9b334a45a8ff | 411 | * @note |
bogdanm | 0:9b334a45a8ff | 412 | * Only single master mode is supported. |
bogdanm | 0:9b334a45a8ff | 413 | * |
bogdanm | 0:9b334a45a8ff | 414 | * @param[in] i2c |
bogdanm | 0:9b334a45a8ff | 415 | * Pointer to I2C peripheral register block. |
bogdanm | 0:9b334a45a8ff | 416 | * |
bogdanm | 0:9b334a45a8ff | 417 | * @return |
bogdanm | 0:9b334a45a8ff | 418 | * Returns status for ongoing transfer. |
bogdanm | 0:9b334a45a8ff | 419 | * @li #i2cTransferInProgress - indicates that transfer not finished. |
bogdanm | 0:9b334a45a8ff | 420 | * @li #i2cTransferDone - transfer completed successfully. |
bogdanm | 0:9b334a45a8ff | 421 | * @li otherwise some sort of error has occurred. |
bogdanm | 0:9b334a45a8ff | 422 | * |
bogdanm | 0:9b334a45a8ff | 423 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 424 | I2C_TransferReturn_TypeDef I2C_Transfer(I2C_TypeDef *i2c) |
bogdanm | 0:9b334a45a8ff | 425 | { |
bogdanm | 0:9b334a45a8ff | 426 | uint32_t tmp; |
bogdanm | 0:9b334a45a8ff | 427 | uint32_t pending; |
bogdanm | 0:9b334a45a8ff | 428 | I2C_Transfer_TypeDef *transfer; |
bogdanm | 0:9b334a45a8ff | 429 | I2C_TransferSeq_TypeDef *seq; |
bogdanm | 0:9b334a45a8ff | 430 | |
bogdanm | 0:9b334a45a8ff | 431 | EFM_ASSERT(I2C_REF_VALID(i2c)); |
bogdanm | 0:9b334a45a8ff | 432 | |
bogdanm | 0:9b334a45a8ff | 433 | /* Support up to 2 I2C buses */ |
bogdanm | 0:9b334a45a8ff | 434 | if (i2c == I2C0) |
bogdanm | 0:9b334a45a8ff | 435 | { |
bogdanm | 0:9b334a45a8ff | 436 | transfer = i2cTransfer; |
bogdanm | 0:9b334a45a8ff | 437 | } |
bogdanm | 0:9b334a45a8ff | 438 | #if (I2C_COUNT > 1) |
bogdanm | 0:9b334a45a8ff | 439 | else if (i2c == I2C1) |
bogdanm | 0:9b334a45a8ff | 440 | { |
bogdanm | 0:9b334a45a8ff | 441 | transfer = i2cTransfer + 1; |
bogdanm | 0:9b334a45a8ff | 442 | } |
bogdanm | 0:9b334a45a8ff | 443 | #endif |
bogdanm | 0:9b334a45a8ff | 444 | else |
bogdanm | 0:9b334a45a8ff | 445 | { |
mbed_official | 50:a417edff4437 | 446 | return i2cTransferUsageFault; |
bogdanm | 0:9b334a45a8ff | 447 | } |
bogdanm | 0:9b334a45a8ff | 448 | |
bogdanm | 0:9b334a45a8ff | 449 | seq = transfer->seq; |
bogdanm | 0:9b334a45a8ff | 450 | for (;; ) |
bogdanm | 0:9b334a45a8ff | 451 | { |
bogdanm | 0:9b334a45a8ff | 452 | pending = i2c->IF; |
bogdanm | 0:9b334a45a8ff | 453 | |
bogdanm | 0:9b334a45a8ff | 454 | /* If some sort of fault, abort transfer. */ |
bogdanm | 0:9b334a45a8ff | 455 | if (pending & I2C_IF_ERRORS) |
bogdanm | 0:9b334a45a8ff | 456 | { |
bogdanm | 0:9b334a45a8ff | 457 | if (pending & I2C_IF_ARBLOST) |
bogdanm | 0:9b334a45a8ff | 458 | { |
bogdanm | 0:9b334a45a8ff | 459 | /* If arbitration fault, it indicates either a slave device */ |
bogdanm | 0:9b334a45a8ff | 460 | /* not responding as expected, or other master which is not */ |
bogdanm | 0:9b334a45a8ff | 461 | /* supported by this SW. */ |
bogdanm | 0:9b334a45a8ff | 462 | transfer->result = i2cTransferArbLost; |
bogdanm | 0:9b334a45a8ff | 463 | } |
bogdanm | 0:9b334a45a8ff | 464 | else if (pending & I2C_IF_BUSERR) |
bogdanm | 0:9b334a45a8ff | 465 | { |
bogdanm | 0:9b334a45a8ff | 466 | /* A bus error indicates a misplaced start or stop, which should */ |
bogdanm | 0:9b334a45a8ff | 467 | /* not occur in master mode controlled by this SW. */ |
bogdanm | 0:9b334a45a8ff | 468 | transfer->result = i2cTransferBusErr; |
bogdanm | 0:9b334a45a8ff | 469 | } |
bogdanm | 0:9b334a45a8ff | 470 | |
bogdanm | 0:9b334a45a8ff | 471 | /* If error situation occurred, it is difficult to know */ |
bogdanm | 0:9b334a45a8ff | 472 | /* exact cause and how to resolve. It will be up to a wrapper */ |
bogdanm | 0:9b334a45a8ff | 473 | /* to determine how to handle a fault/recovery if possible. */ |
bogdanm | 0:9b334a45a8ff | 474 | transfer->state = i2cStateDone; |
bogdanm | 0:9b334a45a8ff | 475 | goto done; |
bogdanm | 0:9b334a45a8ff | 476 | } |
bogdanm | 0:9b334a45a8ff | 477 | |
bogdanm | 0:9b334a45a8ff | 478 | switch (transfer->state) |
bogdanm | 0:9b334a45a8ff | 479 | { |
bogdanm | 0:9b334a45a8ff | 480 | /***************************************************/ |
bogdanm | 0:9b334a45a8ff | 481 | /* Send first start+address (first byte if 10 bit) */ |
bogdanm | 0:9b334a45a8ff | 482 | /***************************************************/ |
bogdanm | 0:9b334a45a8ff | 483 | case i2cStateStartAddrSend: |
bogdanm | 0:9b334a45a8ff | 484 | if (seq->flags & I2C_FLAG_10BIT_ADDR) |
bogdanm | 0:9b334a45a8ff | 485 | { |
bogdanm | 0:9b334a45a8ff | 486 | tmp = (((uint32_t)(seq->addr) >> 8) & 0x06) | 0xf0; |
bogdanm | 0:9b334a45a8ff | 487 | |
bogdanm | 0:9b334a45a8ff | 488 | /* In 10 bit address mode, the address following the first */ |
bogdanm | 0:9b334a45a8ff | 489 | /* start always indicate write. */ |
bogdanm | 0:9b334a45a8ff | 490 | } |
bogdanm | 0:9b334a45a8ff | 491 | else |
bogdanm | 0:9b334a45a8ff | 492 | { |
bogdanm | 0:9b334a45a8ff | 493 | tmp = (uint32_t)(seq->addr) & 0xfe; |
bogdanm | 0:9b334a45a8ff | 494 | |
bogdanm | 0:9b334a45a8ff | 495 | if (seq->flags & I2C_FLAG_READ) |
bogdanm | 0:9b334a45a8ff | 496 | { |
bogdanm | 0:9b334a45a8ff | 497 | /* Indicate read request */ |
bogdanm | 0:9b334a45a8ff | 498 | tmp |= 1; |
bogdanm | 0:9b334a45a8ff | 499 | } |
bogdanm | 0:9b334a45a8ff | 500 | } |
bogdanm | 0:9b334a45a8ff | 501 | |
bogdanm | 0:9b334a45a8ff | 502 | transfer->state = i2cStateAddrWFAckNack; |
bogdanm | 0:9b334a45a8ff | 503 | i2c->TXDATA = tmp; /* Data not transmitted until START sent */ |
bogdanm | 0:9b334a45a8ff | 504 | i2c->CMD = I2C_CMD_START; |
bogdanm | 0:9b334a45a8ff | 505 | goto done; |
bogdanm | 0:9b334a45a8ff | 506 | |
bogdanm | 0:9b334a45a8ff | 507 | /*******************************************************/ |
bogdanm | 0:9b334a45a8ff | 508 | /* Wait for ACK/NACK on address (first byte if 10 bit) */ |
bogdanm | 0:9b334a45a8ff | 509 | /*******************************************************/ |
bogdanm | 0:9b334a45a8ff | 510 | case i2cStateAddrWFAckNack: |
bogdanm | 0:9b334a45a8ff | 511 | if (pending & I2C_IF_NACK) |
bogdanm | 0:9b334a45a8ff | 512 | { |
bogdanm | 0:9b334a45a8ff | 513 | i2c->IFC = I2C_IFC_NACK; |
bogdanm | 0:9b334a45a8ff | 514 | transfer->result = i2cTransferNack; |
bogdanm | 0:9b334a45a8ff | 515 | transfer->state = i2cStateWFStopSent; |
bogdanm | 0:9b334a45a8ff | 516 | i2c->CMD = I2C_CMD_STOP; |
bogdanm | 0:9b334a45a8ff | 517 | } |
bogdanm | 0:9b334a45a8ff | 518 | else if (pending & I2C_IF_ACK) |
bogdanm | 0:9b334a45a8ff | 519 | { |
bogdanm | 0:9b334a45a8ff | 520 | i2c->IFC = I2C_IFC_ACK; |
bogdanm | 0:9b334a45a8ff | 521 | |
bogdanm | 0:9b334a45a8ff | 522 | /* If 10 bit address, send 2nd byte of address. */ |
bogdanm | 0:9b334a45a8ff | 523 | if (seq->flags & I2C_FLAG_10BIT_ADDR) |
bogdanm | 0:9b334a45a8ff | 524 | { |
bogdanm | 0:9b334a45a8ff | 525 | transfer->state = i2cStateAddrWF2ndAckNack; |
bogdanm | 0:9b334a45a8ff | 526 | i2c->TXDATA = (uint32_t)(seq->addr) & 0xff; |
bogdanm | 0:9b334a45a8ff | 527 | } |
bogdanm | 0:9b334a45a8ff | 528 | else |
bogdanm | 0:9b334a45a8ff | 529 | { |
bogdanm | 0:9b334a45a8ff | 530 | /* Determine whether receiving or sending data */ |
bogdanm | 0:9b334a45a8ff | 531 | if (seq->flags & I2C_FLAG_READ) |
bogdanm | 0:9b334a45a8ff | 532 | { |
bogdanm | 0:9b334a45a8ff | 533 | transfer->state = i2cStateWFData; |
bogdanm | 0:9b334a45a8ff | 534 | if(seq->buf[transfer->bufIndx].len==1) |
bogdanm | 0:9b334a45a8ff | 535 | { |
bogdanm | 0:9b334a45a8ff | 536 | i2c->CMD = I2C_CMD_NACK; |
bogdanm | 0:9b334a45a8ff | 537 | } |
bogdanm | 0:9b334a45a8ff | 538 | } |
bogdanm | 0:9b334a45a8ff | 539 | else |
bogdanm | 0:9b334a45a8ff | 540 | { |
bogdanm | 0:9b334a45a8ff | 541 | transfer->state = i2cStateDataSend; |
bogdanm | 0:9b334a45a8ff | 542 | continue; |
bogdanm | 0:9b334a45a8ff | 543 | } |
bogdanm | 0:9b334a45a8ff | 544 | } |
bogdanm | 0:9b334a45a8ff | 545 | } |
bogdanm | 0:9b334a45a8ff | 546 | goto done; |
bogdanm | 0:9b334a45a8ff | 547 | |
bogdanm | 0:9b334a45a8ff | 548 | /******************************************************/ |
bogdanm | 0:9b334a45a8ff | 549 | /* Wait for ACK/NACK on second byte of 10 bit address */ |
bogdanm | 0:9b334a45a8ff | 550 | /******************************************************/ |
bogdanm | 0:9b334a45a8ff | 551 | case i2cStateAddrWF2ndAckNack: |
bogdanm | 0:9b334a45a8ff | 552 | if (pending & I2C_IF_NACK) |
bogdanm | 0:9b334a45a8ff | 553 | { |
bogdanm | 0:9b334a45a8ff | 554 | i2c->IFC = I2C_IFC_NACK; |
bogdanm | 0:9b334a45a8ff | 555 | transfer->result = i2cTransferNack; |
bogdanm | 0:9b334a45a8ff | 556 | transfer->state = i2cStateWFStopSent; |
bogdanm | 0:9b334a45a8ff | 557 | i2c->CMD = I2C_CMD_STOP; |
bogdanm | 0:9b334a45a8ff | 558 | } |
bogdanm | 0:9b334a45a8ff | 559 | else if (pending & I2C_IF_ACK) |
bogdanm | 0:9b334a45a8ff | 560 | { |
bogdanm | 0:9b334a45a8ff | 561 | i2c->IFC = I2C_IFC_ACK; |
bogdanm | 0:9b334a45a8ff | 562 | |
bogdanm | 0:9b334a45a8ff | 563 | /* If using plain read sequence with 10 bit address, switch to send */ |
bogdanm | 0:9b334a45a8ff | 564 | /* repeated start. */ |
bogdanm | 0:9b334a45a8ff | 565 | if (seq->flags & I2C_FLAG_READ) |
bogdanm | 0:9b334a45a8ff | 566 | { |
bogdanm | 0:9b334a45a8ff | 567 | transfer->state = i2cStateRStartAddrSend; |
bogdanm | 0:9b334a45a8ff | 568 | } |
bogdanm | 0:9b334a45a8ff | 569 | /* Otherwise expected to write 0 or more bytes */ |
bogdanm | 0:9b334a45a8ff | 570 | else |
bogdanm | 0:9b334a45a8ff | 571 | { |
bogdanm | 0:9b334a45a8ff | 572 | transfer->state = i2cStateDataSend; |
bogdanm | 0:9b334a45a8ff | 573 | } |
bogdanm | 0:9b334a45a8ff | 574 | continue; |
bogdanm | 0:9b334a45a8ff | 575 | } |
bogdanm | 0:9b334a45a8ff | 576 | goto done; |
bogdanm | 0:9b334a45a8ff | 577 | |
bogdanm | 0:9b334a45a8ff | 578 | /*******************************/ |
bogdanm | 0:9b334a45a8ff | 579 | /* Send repeated start+address */ |
bogdanm | 0:9b334a45a8ff | 580 | /*******************************/ |
bogdanm | 0:9b334a45a8ff | 581 | case i2cStateRStartAddrSend: |
bogdanm | 0:9b334a45a8ff | 582 | if (seq->flags & I2C_FLAG_10BIT_ADDR) |
bogdanm | 0:9b334a45a8ff | 583 | { |
bogdanm | 0:9b334a45a8ff | 584 | tmp = ((seq->addr >> 8) & 0x06) | 0xf0; |
bogdanm | 0:9b334a45a8ff | 585 | } |
bogdanm | 0:9b334a45a8ff | 586 | else |
bogdanm | 0:9b334a45a8ff | 587 | { |
bogdanm | 0:9b334a45a8ff | 588 | tmp = seq->addr & 0xfe; |
bogdanm | 0:9b334a45a8ff | 589 | } |
bogdanm | 0:9b334a45a8ff | 590 | |
bogdanm | 0:9b334a45a8ff | 591 | /* If this is a write+read combined sequence, then read is about to start */ |
bogdanm | 0:9b334a45a8ff | 592 | if (seq->flags & I2C_FLAG_WRITE_READ) |
bogdanm | 0:9b334a45a8ff | 593 | { |
bogdanm | 0:9b334a45a8ff | 594 | /* Indicate read request */ |
bogdanm | 0:9b334a45a8ff | 595 | tmp |= 1; |
bogdanm | 0:9b334a45a8ff | 596 | } |
bogdanm | 0:9b334a45a8ff | 597 | |
bogdanm | 0:9b334a45a8ff | 598 | transfer->state = i2cStateRAddrWFAckNack; |
bogdanm | 0:9b334a45a8ff | 599 | /* We have to write START cmd first since repeated start, otherwise */ |
bogdanm | 0:9b334a45a8ff | 600 | /* data would be sent first. */ |
bogdanm | 0:9b334a45a8ff | 601 | i2c->CMD = I2C_CMD_START; |
bogdanm | 0:9b334a45a8ff | 602 | i2c->TXDATA = tmp; |
bogdanm | 0:9b334a45a8ff | 603 | goto done; |
bogdanm | 0:9b334a45a8ff | 604 | |
bogdanm | 0:9b334a45a8ff | 605 | /**********************************************************************/ |
bogdanm | 0:9b334a45a8ff | 606 | /* Wait for ACK/NACK on repeated start+address (first byte if 10 bit) */ |
bogdanm | 0:9b334a45a8ff | 607 | /**********************************************************************/ |
bogdanm | 0:9b334a45a8ff | 608 | case i2cStateRAddrWFAckNack: |
bogdanm | 0:9b334a45a8ff | 609 | if (pending & I2C_IF_NACK) |
bogdanm | 0:9b334a45a8ff | 610 | { |
bogdanm | 0:9b334a45a8ff | 611 | i2c->IFC = I2C_IFC_NACK; |
bogdanm | 0:9b334a45a8ff | 612 | transfer->result = i2cTransferNack; |
bogdanm | 0:9b334a45a8ff | 613 | transfer->state = i2cStateWFStopSent; |
bogdanm | 0:9b334a45a8ff | 614 | i2c->CMD = I2C_CMD_STOP; |
bogdanm | 0:9b334a45a8ff | 615 | } |
bogdanm | 0:9b334a45a8ff | 616 | else if (pending & I2C_IF_ACK) |
bogdanm | 0:9b334a45a8ff | 617 | { |
bogdanm | 0:9b334a45a8ff | 618 | i2c->IFC = I2C_IFC_ACK; |
bogdanm | 0:9b334a45a8ff | 619 | |
bogdanm | 0:9b334a45a8ff | 620 | /* Determine whether receiving or sending data */ |
bogdanm | 0:9b334a45a8ff | 621 | if (seq->flags & I2C_FLAG_WRITE_READ) |
bogdanm | 0:9b334a45a8ff | 622 | { |
bogdanm | 0:9b334a45a8ff | 623 | transfer->state = i2cStateWFData; |
bogdanm | 0:9b334a45a8ff | 624 | } |
bogdanm | 0:9b334a45a8ff | 625 | else |
bogdanm | 0:9b334a45a8ff | 626 | { |
bogdanm | 0:9b334a45a8ff | 627 | transfer->state = i2cStateDataSend; |
bogdanm | 0:9b334a45a8ff | 628 | continue; |
bogdanm | 0:9b334a45a8ff | 629 | } |
bogdanm | 0:9b334a45a8ff | 630 | } |
bogdanm | 0:9b334a45a8ff | 631 | goto done; |
bogdanm | 0:9b334a45a8ff | 632 | |
bogdanm | 0:9b334a45a8ff | 633 | /*****************************/ |
bogdanm | 0:9b334a45a8ff | 634 | /* Send a data byte to slave */ |
bogdanm | 0:9b334a45a8ff | 635 | /*****************************/ |
bogdanm | 0:9b334a45a8ff | 636 | case i2cStateDataSend: |
bogdanm | 0:9b334a45a8ff | 637 | /* Reached end of data buffer? */ |
bogdanm | 0:9b334a45a8ff | 638 | if (transfer->offset >= seq->buf[transfer->bufIndx].len) |
bogdanm | 0:9b334a45a8ff | 639 | { |
bogdanm | 0:9b334a45a8ff | 640 | /* Move to next message part */ |
bogdanm | 0:9b334a45a8ff | 641 | transfer->offset = 0; |
bogdanm | 0:9b334a45a8ff | 642 | transfer->bufIndx++; |
bogdanm | 0:9b334a45a8ff | 643 | |
bogdanm | 0:9b334a45a8ff | 644 | /* Send repeated start when switching to read mode on 2nd buffer */ |
bogdanm | 0:9b334a45a8ff | 645 | if (seq->flags & I2C_FLAG_WRITE_READ) |
bogdanm | 0:9b334a45a8ff | 646 | { |
bogdanm | 0:9b334a45a8ff | 647 | transfer->state = i2cStateRStartAddrSend; |
bogdanm | 0:9b334a45a8ff | 648 | continue; |
bogdanm | 0:9b334a45a8ff | 649 | } |
bogdanm | 0:9b334a45a8ff | 650 | |
bogdanm | 0:9b334a45a8ff | 651 | /* Only writing from one buffer, or finished both buffers */ |
bogdanm | 0:9b334a45a8ff | 652 | if ((seq->flags & I2C_FLAG_WRITE) || (transfer->bufIndx > 1)) |
bogdanm | 0:9b334a45a8ff | 653 | { |
bogdanm | 0:9b334a45a8ff | 654 | transfer->state = i2cStateWFStopSent; |
bogdanm | 0:9b334a45a8ff | 655 | i2c->CMD = I2C_CMD_STOP; |
bogdanm | 0:9b334a45a8ff | 656 | goto done; |
bogdanm | 0:9b334a45a8ff | 657 | } |
bogdanm | 0:9b334a45a8ff | 658 | |
bogdanm | 0:9b334a45a8ff | 659 | /* Reprocess in case next buffer is empty */ |
bogdanm | 0:9b334a45a8ff | 660 | continue; |
bogdanm | 0:9b334a45a8ff | 661 | } |
bogdanm | 0:9b334a45a8ff | 662 | |
bogdanm | 0:9b334a45a8ff | 663 | /* Send byte */ |
bogdanm | 0:9b334a45a8ff | 664 | i2c->TXDATA = (uint32_t)(seq->buf[transfer->bufIndx].data[transfer->offset++]); |
bogdanm | 0:9b334a45a8ff | 665 | transfer->state = i2cStateDataWFAckNack; |
bogdanm | 0:9b334a45a8ff | 666 | goto done; |
bogdanm | 0:9b334a45a8ff | 667 | |
bogdanm | 0:9b334a45a8ff | 668 | /*********************************************************/ |
bogdanm | 0:9b334a45a8ff | 669 | /* Wait for ACK/NACK from slave after sending data to it */ |
bogdanm | 0:9b334a45a8ff | 670 | /*********************************************************/ |
bogdanm | 0:9b334a45a8ff | 671 | case i2cStateDataWFAckNack: |
bogdanm | 0:9b334a45a8ff | 672 | if (pending & I2C_IF_NACK) |
bogdanm | 0:9b334a45a8ff | 673 | { |
bogdanm | 0:9b334a45a8ff | 674 | i2c->IFC = I2C_IFC_NACK; |
bogdanm | 0:9b334a45a8ff | 675 | transfer->result = i2cTransferNack; |
bogdanm | 0:9b334a45a8ff | 676 | transfer->state = i2cStateWFStopSent; |
bogdanm | 0:9b334a45a8ff | 677 | i2c->CMD = I2C_CMD_STOP; |
bogdanm | 0:9b334a45a8ff | 678 | } |
bogdanm | 0:9b334a45a8ff | 679 | else if (pending & I2C_IF_ACK) |
bogdanm | 0:9b334a45a8ff | 680 | { |
bogdanm | 0:9b334a45a8ff | 681 | i2c->IFC = I2C_IFC_ACK; |
bogdanm | 0:9b334a45a8ff | 682 | transfer->state = i2cStateDataSend; |
bogdanm | 0:9b334a45a8ff | 683 | continue; |
bogdanm | 0:9b334a45a8ff | 684 | } |
bogdanm | 0:9b334a45a8ff | 685 | goto done; |
bogdanm | 0:9b334a45a8ff | 686 | |
bogdanm | 0:9b334a45a8ff | 687 | /****************************/ |
bogdanm | 0:9b334a45a8ff | 688 | /* Wait for data from slave */ |
bogdanm | 0:9b334a45a8ff | 689 | /****************************/ |
bogdanm | 0:9b334a45a8ff | 690 | case i2cStateWFData: |
bogdanm | 0:9b334a45a8ff | 691 | if (pending & I2C_IF_RXDATAV) |
bogdanm | 0:9b334a45a8ff | 692 | { |
bogdanm | 0:9b334a45a8ff | 693 | uint8_t data; |
bogdanm | 0:9b334a45a8ff | 694 | unsigned int rxLen = seq->buf[transfer->bufIndx].len; |
bogdanm | 0:9b334a45a8ff | 695 | |
bogdanm | 0:9b334a45a8ff | 696 | /* Must read out data in order to not block further progress */ |
bogdanm | 0:9b334a45a8ff | 697 | data = (uint8_t)(i2c->RXDATA); |
bogdanm | 0:9b334a45a8ff | 698 | |
bogdanm | 0:9b334a45a8ff | 699 | /* Make sure not storing beyond end of buffer just in case */ |
bogdanm | 0:9b334a45a8ff | 700 | if (transfer->offset < rxLen) |
bogdanm | 0:9b334a45a8ff | 701 | { |
bogdanm | 0:9b334a45a8ff | 702 | seq->buf[transfer->bufIndx].data[transfer->offset++] = data; |
bogdanm | 0:9b334a45a8ff | 703 | } |
bogdanm | 0:9b334a45a8ff | 704 | |
bogdanm | 0:9b334a45a8ff | 705 | /* If we have read all requested data, then the sequence should end */ |
bogdanm | 0:9b334a45a8ff | 706 | if (transfer->offset >= rxLen) |
bogdanm | 0:9b334a45a8ff | 707 | { |
bogdanm | 0:9b334a45a8ff | 708 | /* If there is only one byte to receive we need to transmit the |
bogdanm | 0:9b334a45a8ff | 709 | NACK now, before the stop. */ |
bogdanm | 0:9b334a45a8ff | 710 | if (1 == rxLen) |
bogdanm | 0:9b334a45a8ff | 711 | { |
bogdanm | 0:9b334a45a8ff | 712 | i2c->CMD = I2C_CMD_NACK; |
bogdanm | 0:9b334a45a8ff | 713 | } |
bogdanm | 0:9b334a45a8ff | 714 | |
bogdanm | 0:9b334a45a8ff | 715 | transfer->state = i2cStateWFStopSent; |
bogdanm | 0:9b334a45a8ff | 716 | i2c->CMD = I2C_CMD_STOP; |
bogdanm | 0:9b334a45a8ff | 717 | } |
bogdanm | 0:9b334a45a8ff | 718 | else |
bogdanm | 0:9b334a45a8ff | 719 | { |
bogdanm | 0:9b334a45a8ff | 720 | /* Send ACK and wait for next byte */ |
bogdanm | 0:9b334a45a8ff | 721 | i2c->CMD = I2C_CMD_ACK; |
bogdanm | 0:9b334a45a8ff | 722 | |
bogdanm | 0:9b334a45a8ff | 723 | if ( (1<rxLen) && (transfer->offset == (rxLen-1)) ) |
bogdanm | 0:9b334a45a8ff | 724 | { |
bogdanm | 0:9b334a45a8ff | 725 | /* If there is more than one byte to receive and this is the next |
bogdanm | 0:9b334a45a8ff | 726 | to last byte we need to transmit the NACK now, before receiving |
bogdanm | 0:9b334a45a8ff | 727 | the last byte. */ |
bogdanm | 0:9b334a45a8ff | 728 | i2c->CMD = I2C_CMD_NACK; |
bogdanm | 0:9b334a45a8ff | 729 | } |
bogdanm | 0:9b334a45a8ff | 730 | } |
bogdanm | 0:9b334a45a8ff | 731 | } |
bogdanm | 0:9b334a45a8ff | 732 | goto done; |
bogdanm | 0:9b334a45a8ff | 733 | |
bogdanm | 0:9b334a45a8ff | 734 | /***********************************/ |
bogdanm | 0:9b334a45a8ff | 735 | /* Wait for STOP to have been sent */ |
bogdanm | 0:9b334a45a8ff | 736 | /***********************************/ |
bogdanm | 0:9b334a45a8ff | 737 | case i2cStateWFStopSent: |
bogdanm | 0:9b334a45a8ff | 738 | if (pending & I2C_IF_MSTOP) |
bogdanm | 0:9b334a45a8ff | 739 | { |
bogdanm | 0:9b334a45a8ff | 740 | i2c->IFC = I2C_IFC_MSTOP; |
bogdanm | 0:9b334a45a8ff | 741 | transfer->state = i2cStateDone; |
bogdanm | 0:9b334a45a8ff | 742 | } |
bogdanm | 0:9b334a45a8ff | 743 | goto done; |
bogdanm | 0:9b334a45a8ff | 744 | |
bogdanm | 0:9b334a45a8ff | 745 | /******************************/ |
bogdanm | 0:9b334a45a8ff | 746 | /* Unexpected state, SW fault */ |
bogdanm | 0:9b334a45a8ff | 747 | /******************************/ |
bogdanm | 0:9b334a45a8ff | 748 | default: |
bogdanm | 0:9b334a45a8ff | 749 | transfer->result = i2cTransferSwFault; |
bogdanm | 0:9b334a45a8ff | 750 | transfer->state = i2cStateDone; |
bogdanm | 0:9b334a45a8ff | 751 | goto done; |
bogdanm | 0:9b334a45a8ff | 752 | } |
bogdanm | 0:9b334a45a8ff | 753 | } |
bogdanm | 0:9b334a45a8ff | 754 | |
bogdanm | 0:9b334a45a8ff | 755 | done: |
bogdanm | 0:9b334a45a8ff | 756 | |
bogdanm | 0:9b334a45a8ff | 757 | if (transfer->state == i2cStateDone) |
bogdanm | 0:9b334a45a8ff | 758 | { |
bogdanm | 0:9b334a45a8ff | 759 | /* Disable interrupt sources when done */ |
bogdanm | 0:9b334a45a8ff | 760 | i2c->IEN = 0; |
bogdanm | 0:9b334a45a8ff | 761 | |
bogdanm | 0:9b334a45a8ff | 762 | /* Update result unless some fault already occurred */ |
bogdanm | 0:9b334a45a8ff | 763 | if (transfer->result == i2cTransferInProgress) |
bogdanm | 0:9b334a45a8ff | 764 | { |
bogdanm | 0:9b334a45a8ff | 765 | transfer->result = i2cTransferDone; |
bogdanm | 0:9b334a45a8ff | 766 | } |
bogdanm | 0:9b334a45a8ff | 767 | } |
bogdanm | 0:9b334a45a8ff | 768 | /* Until transfer is done keep returning i2cTransferInProgress */ |
bogdanm | 0:9b334a45a8ff | 769 | else |
bogdanm | 0:9b334a45a8ff | 770 | { |
mbed_official | 50:a417edff4437 | 771 | return i2cTransferInProgress; |
bogdanm | 0:9b334a45a8ff | 772 | } |
bogdanm | 0:9b334a45a8ff | 773 | |
bogdanm | 0:9b334a45a8ff | 774 | return transfer->result; |
bogdanm | 0:9b334a45a8ff | 775 | } |
bogdanm | 0:9b334a45a8ff | 776 | |
bogdanm | 0:9b334a45a8ff | 777 | |
bogdanm | 0:9b334a45a8ff | 778 | /***************************************************************************//** |
bogdanm | 0:9b334a45a8ff | 779 | * @brief |
bogdanm | 0:9b334a45a8ff | 780 | * Prepare and start an I2C transfer (single master mode only). |
bogdanm | 0:9b334a45a8ff | 781 | * |
bogdanm | 0:9b334a45a8ff | 782 | * @details |
bogdanm | 0:9b334a45a8ff | 783 | * This function must be invoked in order to start an I2C transfer |
bogdanm | 0:9b334a45a8ff | 784 | * sequence. In order to actually complete the transfer, I2C_Transfer() must |
bogdanm | 0:9b334a45a8ff | 785 | * be used either in polled mode or by adding a small driver wrapper utilizing |
bogdanm | 0:9b334a45a8ff | 786 | * interrupts. |
bogdanm | 0:9b334a45a8ff | 787 | * |
bogdanm | 0:9b334a45a8ff | 788 | * @note |
bogdanm | 0:9b334a45a8ff | 789 | * Only single master mode is supported. |
bogdanm | 0:9b334a45a8ff | 790 | * |
bogdanm | 0:9b334a45a8ff | 791 | * @param[in] i2c |
bogdanm | 0:9b334a45a8ff | 792 | * Pointer to I2C peripheral register block. |
bogdanm | 0:9b334a45a8ff | 793 | * |
bogdanm | 0:9b334a45a8ff | 794 | * @param[in] seq |
bogdanm | 0:9b334a45a8ff | 795 | * Pointer to sequence structure defining the I2C transfer to take place. The |
bogdanm | 0:9b334a45a8ff | 796 | * referenced structure must exist until the transfer has fully completed. |
bogdanm | 0:9b334a45a8ff | 797 | * |
bogdanm | 0:9b334a45a8ff | 798 | * @return |
bogdanm | 0:9b334a45a8ff | 799 | * Returns status for ongoing transfer: |
bogdanm | 0:9b334a45a8ff | 800 | * @li #i2cTransferInProgress - indicates that transfer not finished. |
bogdanm | 0:9b334a45a8ff | 801 | * @li otherwise some sort of error has occurred. |
bogdanm | 0:9b334a45a8ff | 802 | ******************************************************************************/ |
bogdanm | 0:9b334a45a8ff | 803 | I2C_TransferReturn_TypeDef I2C_TransferInit(I2C_TypeDef *i2c, |
bogdanm | 0:9b334a45a8ff | 804 | I2C_TransferSeq_TypeDef *seq) |
bogdanm | 0:9b334a45a8ff | 805 | { |
bogdanm | 0:9b334a45a8ff | 806 | I2C_Transfer_TypeDef *transfer; |
bogdanm | 0:9b334a45a8ff | 807 | |
bogdanm | 0:9b334a45a8ff | 808 | EFM_ASSERT(I2C_REF_VALID(i2c)); |
bogdanm | 0:9b334a45a8ff | 809 | EFM_ASSERT(seq); |
bogdanm | 0:9b334a45a8ff | 810 | |
bogdanm | 0:9b334a45a8ff | 811 | /* Support up to 2 I2C buses */ |
bogdanm | 0:9b334a45a8ff | 812 | if (i2c == I2C0) |
bogdanm | 0:9b334a45a8ff | 813 | { |
bogdanm | 0:9b334a45a8ff | 814 | transfer = i2cTransfer; |
bogdanm | 0:9b334a45a8ff | 815 | } |
bogdanm | 0:9b334a45a8ff | 816 | #if (I2C_COUNT > 1) |
bogdanm | 0:9b334a45a8ff | 817 | else if (i2c == I2C1) |
bogdanm | 0:9b334a45a8ff | 818 | { |
bogdanm | 0:9b334a45a8ff | 819 | transfer = i2cTransfer + 1; |
bogdanm | 0:9b334a45a8ff | 820 | } |
bogdanm | 0:9b334a45a8ff | 821 | #endif |
bogdanm | 0:9b334a45a8ff | 822 | else |
bogdanm | 0:9b334a45a8ff | 823 | { |
mbed_official | 50:a417edff4437 | 824 | return i2cTransferUsageFault; |
bogdanm | 0:9b334a45a8ff | 825 | } |
bogdanm | 0:9b334a45a8ff | 826 | |
bogdanm | 0:9b334a45a8ff | 827 | /* Check if in busy state. Since this SW assumes single master, we can */ |
bogdanm | 0:9b334a45a8ff | 828 | /* just issue an abort. The BUSY state is normal after a reset. */ |
bogdanm | 0:9b334a45a8ff | 829 | if (i2c->STATE & I2C_STATE_BUSY) |
bogdanm | 0:9b334a45a8ff | 830 | { |
bogdanm | 0:9b334a45a8ff | 831 | i2c->CMD = I2C_CMD_ABORT; |
bogdanm | 0:9b334a45a8ff | 832 | } |
bogdanm | 0:9b334a45a8ff | 833 | |
bogdanm | 0:9b334a45a8ff | 834 | /* Make sure user is not trying to read 0 bytes, it is not */ |
bogdanm | 0:9b334a45a8ff | 835 | /* possible according to I2C spec, since slave will always start */ |
bogdanm | 0:9b334a45a8ff | 836 | /* sending first byte ACK on address. The read operation can */ |
bogdanm | 0:9b334a45a8ff | 837 | /* only be stopped by NACKing a received byte, ie minimum 1 byte. */ |
bogdanm | 0:9b334a45a8ff | 838 | if (((seq->flags & I2C_FLAG_READ) && !(seq->buf[0].len)) || |
bogdanm | 0:9b334a45a8ff | 839 | ((seq->flags & I2C_FLAG_WRITE_READ) && !(seq->buf[1].len)) |
bogdanm | 0:9b334a45a8ff | 840 | ) |
bogdanm | 0:9b334a45a8ff | 841 | { |
mbed_official | 50:a417edff4437 | 842 | return i2cTransferUsageFault; |
bogdanm | 0:9b334a45a8ff | 843 | } |
bogdanm | 0:9b334a45a8ff | 844 | |
bogdanm | 0:9b334a45a8ff | 845 | /* Prepare for a transfer */ |
bogdanm | 0:9b334a45a8ff | 846 | transfer->state = i2cStateStartAddrSend; |
bogdanm | 0:9b334a45a8ff | 847 | transfer->result = i2cTransferInProgress; |
bogdanm | 0:9b334a45a8ff | 848 | transfer->offset = 0; |
bogdanm | 0:9b334a45a8ff | 849 | transfer->bufIndx = 0; |
bogdanm | 0:9b334a45a8ff | 850 | transfer->seq = seq; |
bogdanm | 0:9b334a45a8ff | 851 | |
bogdanm | 0:9b334a45a8ff | 852 | /* Ensure buffers are empty */ |
bogdanm | 0:9b334a45a8ff | 853 | i2c->CMD = I2C_CMD_CLEARPC | I2C_CMD_CLEARTX; |
bogdanm | 0:9b334a45a8ff | 854 | if (i2c->IF & I2C_IF_RXDATAV) |
bogdanm | 0:9b334a45a8ff | 855 | { |
bogdanm | 0:9b334a45a8ff | 856 | (void)i2c->RXDATA; |
bogdanm | 0:9b334a45a8ff | 857 | } |
bogdanm | 0:9b334a45a8ff | 858 | |
bogdanm | 0:9b334a45a8ff | 859 | /* Clear all pending interrupts prior to starting transfer. */ |
bogdanm | 0:9b334a45a8ff | 860 | i2c->IFC = _I2C_IFC_MASK; |
bogdanm | 0:9b334a45a8ff | 861 | |
bogdanm | 0:9b334a45a8ff | 862 | /* Enable those interrupts we are interested in throughout transfer. */ |
bogdanm | 0:9b334a45a8ff | 863 | /* Notice that the I2C interrupt must also be enabled in the NVIC, but */ |
bogdanm | 0:9b334a45a8ff | 864 | /* that is left for an additional driver wrapper. */ |
bogdanm | 0:9b334a45a8ff | 865 | i2c->IEN = I2C_IF_NACK | I2C_IF_ACK | I2C_IF_MSTOP | |
bogdanm | 0:9b334a45a8ff | 866 | I2C_IF_RXDATAV | I2C_IF_ERRORS; |
bogdanm | 0:9b334a45a8ff | 867 | |
bogdanm | 0:9b334a45a8ff | 868 | /* Start transfer */ |
mbed_official | 50:a417edff4437 | 869 | return I2C_Transfer(i2c); |
bogdanm | 0:9b334a45a8ff | 870 | } |
bogdanm | 0:9b334a45a8ff | 871 | |
bogdanm | 0:9b334a45a8ff | 872 | /** @} (end addtogroup I2C) */ |
bogdanm | 0:9b334a45a8ff | 873 | /** @} (end addtogroup EM_Library) */ |
bogdanm | 0:9b334a45a8ff | 874 | #endif /* defined(I2C_COUNT) && (I2C_COUNT > 0) */ |