diff options
Diffstat (limited to 'tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC15XX/i2c_api.c')
| -rw-r--r-- | tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC15XX/i2c_api.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC15XX/i2c_api.c b/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC15XX/i2c_api.c new file mode 100644 index 000000000..0ca7c7dcc --- /dev/null +++ b/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC15XX/i2c_api.c @@ -0,0 +1,217 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2013 ARM Limited + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#include "mbed_assert.h" +#include "i2c_api.h" +#include "cmsis.h" +#include "pinmap.h" + +static uint8_t repeated_start = 0; + +#define I2C_STAT(x) ((LPC_I2C0->STAT >> 1) & (0x07)) + +static inline int i2c_status(i2c_t *obj) { + return I2C_STAT(obj); +} + +// Wait until the Serial Interrupt (SI) is set +static int i2c_wait_SI(i2c_t *obj) { + volatile int timeout = 0; + while (!(LPC_I2C0->STAT & (1 << 0))) { + timeout++; + if (timeout > 100000) return -1; + } + return 0; +} + +static inline void i2c_interface_enable(i2c_t *obj) { + LPC_I2C0->CFG |= (1 << 0); +} + +void i2c_init(i2c_t *obj, PinName sda, PinName scl) { + MBED_ASSERT((sda == P0_23) && (scl == P0_22)); + + // Enables clock for I2C0 + LPC_SYSCON->SYSAHBCLKCTRL1 |= (1 << 13); + + LPC_SYSCON->PRESETCTRL1 |= (1 << 13); + LPC_SYSCON->PRESETCTRL1 &= ~(1 << 13); + + // pin enable + LPC_SWM->PINENABLE1 &= ~(0x3 << 3); + + // set default frequency at 100kHz + i2c_frequency(obj, 100000); + i2c_interface_enable(obj); +} + +inline int i2c_start(i2c_t *obj) { + int status = 0; + if (repeated_start) { + LPC_I2C0->MSTCTL = (1 << 1) | (1 << 0); + repeated_start = 0; + } else { + LPC_I2C0->MSTCTL = (1 << 1); + } + return status; +} + +inline int i2c_stop(i2c_t *obj) { + volatile int timeout = 0; + + LPC_I2C0->MSTCTL = (1 << 2) | (1 << 0); + while ((LPC_I2C0->STAT & ((1 << 0) | (7 << 1))) != ((1 << 0) | (0 << 1))) { + timeout ++; + if (timeout > 100000) return 1; + } + + return 0; +} + + +static inline int i2c_do_write(i2c_t *obj, int value, uint8_t addr) { + // write the data + LPC_I2C0->MSTDAT = value; + + if (!addr) + LPC_I2C0->MSTCTL = (1 << 0); + + // wait and return status + i2c_wait_SI(obj); + return i2c_status(obj); +} + +static inline int i2c_do_read(i2c_t *obj, int last) { + // wait for it to arrive + i2c_wait_SI(obj); + if (!last) + LPC_I2C0->MSTCTL = (1 << 0); + + // return the data + return (LPC_I2C0->MSTDAT & 0xFF); +} + +void i2c_frequency(i2c_t *obj, int hz) { + // No peripheral clock divider on the M0 + uint32_t PCLK = SystemCoreClock; + uint32_t clkdiv = PCLK / (hz * 4) - 1; + + LPC_I2C0->DIV = clkdiv; + LPC_I2C0->MSTTIME = 0; +} + +int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) { + int count, status; + + i2c_start(obj); + + LPC_I2C0->MSTDAT = (address | 0x01); + LPC_I2C0->MSTCTL |= 0x20; + if (i2c_wait_SI(obj) == -1) + return -1; + + status = ((LPC_I2C0->STAT >> 1) & (0x07)); + if (status != 0x01) { + i2c_stop(obj); + return I2C_ERROR_NO_SLAVE; + } + + // Read in all except last byte + for (count = 0; count < (length - 1); count++) { + if (i2c_wait_SI(obj) == -1) + return -1; + LPC_I2C0->MSTCTL = (1 << 0); + data[count] = (LPC_I2C0->MSTDAT & 0xFF); + status = ((LPC_I2C0->STAT >> 1) & (0x07)); + if (status != 0x01) { + i2c_stop(obj); + return count; + } + } + + // read in last byte + if (i2c_wait_SI(obj) == -1) + return -1; + + data[count] = (LPC_I2C0->MSTDAT & 0xFF); + status = i2c_status(obj); + if (status != 0x01) { + i2c_stop(obj); + return length - 1; + } + // If not repeated start, send stop. + if (stop) { + i2c_stop(obj); + } else { + repeated_start = 1; + } + + return length; +} + +int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop) { + int i, status; + + i2c_start(obj); + + LPC_I2C0->MSTDAT = (address & 0xFE); + LPC_I2C0->MSTCTL |= 0x20; + if (i2c_wait_SI(obj) == -1) + return -1; + + status = ((LPC_I2C0->STAT >> 1) & (0x07)); + if (status != 0x02) { + i2c_stop(obj); + return I2C_ERROR_NO_SLAVE; + } + + for (i=0; i<length; i++) { + LPC_I2C0->MSTDAT = data[i]; + LPC_I2C0->MSTCTL = (1 << 0); + if (i2c_wait_SI(obj) == -1) + return -1; + + status = ((LPC_I2C0->STAT >> 1) & (0x07)); + if (status != 0x02) { + i2c_stop(obj); + return i; + } + } + + // If not repeated start, send stop. + if (stop) { + i2c_stop(obj); + } else { + repeated_start = 1; + } + + return length; +} + +void i2c_reset(i2c_t *obj) { + i2c_stop(obj); +} + +int i2c_byte_read(i2c_t *obj, int last) { + return (i2c_do_read(obj, last) & 0xFF); +} + +int i2c_byte_write(i2c_t *obj, int data) { + if (i2c_do_write(obj, (data & 0xFF), 0) == 2) { + return 1; + } else { + return 0; + } +} |