+++ /dev/null
-/* 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.
- *
- * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
- */
-#include "i2c_api.h"
-#include "cmsis.h"
-#include "pinmap.h"
-#include "mbed_error.h"
-
-// SCU mode for I2C SCL/SDA pins
-#define SCU_PINIO_I2C SCU_PINIO_PULLNONE
-
-static const PinMap PinMap_I2C_SDA[] = {
- {P_DED, I2C_0, 0},
- {P2_3, I2C_1, (SCU_PINIO_I2C | 1)},
- {PE_13, I2C_1, (SCU_PINIO_I2C | 2)},
- {NC, NC, 0}
-};
-
-static const PinMap PinMap_I2C_SCL[] = {
- {P_DED, I2C_0, 0},
- {P2_4, I2C_1, (SCU_PINIO_I2C | 1)},
- {PE_14, I2C_1, (SCU_PINIO_I2C | 2)},
- {NC, NC, 0}
-};
-
-#define I2C_CONSET(x) (x->i2c->CONSET)
-#define I2C_CONCLR(x) (x->i2c->CONCLR)
-#define I2C_STAT(x) (x->i2c->STAT)
-#define I2C_DAT(x) (x->i2c->DAT)
-#define I2C_SCLL(x, val) (x->i2c->SCLL = val)
-#define I2C_SCLH(x, val) (x->i2c->SCLH = val)
-
-static const uint32_t I2C_addr_offset[2][4] = {
- {0x0C, 0x20, 0x24, 0x28},
- {0x30, 0x34, 0x38, 0x3C}
-};
-
-static inline void i2c_conclr(i2c_t *obj, int start, int stop, int interrupt, int acknowledge) {
- I2C_CONCLR(obj) = (start << 5)
- | (stop << 4)
- | (interrupt << 3)
- | (acknowledge << 2);
-}
-
-static inline void i2c_conset(i2c_t *obj, int start, int stop, int interrupt, int acknowledge) {
- I2C_CONSET(obj) = (start << 5)
- | (stop << 4)
- | (interrupt << 3)
- | (acknowledge << 2);
-}
-
-// Clear the Serial Interrupt (SI)
-static inline void i2c_clear_SI(i2c_t *obj) {
- i2c_conclr(obj, 0, 0, 1, 0);
-}
-
-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) {
- int timeout = 0;
- while (!(I2C_CONSET(obj) & (1 << 3))) {
- timeout++;
- if (timeout > 100000) return -1;
- }
- return 0;
-}
-
-static inline void i2c_interface_enable(i2c_t *obj) {
- I2C_CONSET(obj) = 0x40;
-}
-
-void i2c_init(i2c_t *obj, PinName sda, PinName scl) {
- // determine the SPI to use
- I2CName i2c_sda = (I2CName)pinmap_peripheral(sda, PinMap_I2C_SDA);
- I2CName i2c_scl = (I2CName)pinmap_peripheral(scl, PinMap_I2C_SCL);
- obj->i2c = (LPC_I2C_T *)pinmap_merge(i2c_sda, i2c_scl);
-
- if ((int)obj->i2c == NC) {
- error("I2C pin mapping failed");
- }
-
- // set default frequency at 100k
- i2c_frequency(obj, 100000);
- i2c_conclr(obj, 1, 1, 1, 1);
- i2c_interface_enable(obj);
-
- // Set SCU functions
- if (scl == P_DED) {
- // Enable dedicated I2C0 SDA and SCL pins (open drain)
- LPC_SCU->SFSI2C0 = (1 << 11) | (1 << 3);
- } else {
- pinmap_pinout(sda, PinMap_I2C_SDA);
- pinmap_pinout(scl, PinMap_I2C_SCL);
- }
-}
-
-inline int i2c_start(i2c_t *obj) {
- int status = 0;
- // 8.1 Before master mode can be entered, I2CON must be initialised to:
- // - I2EN STA STO SI AA - -
- // - 1 0 0 0 x - -
- // if AA = 0, it can't enter slave mode
- i2c_conclr(obj, 1, 1, 1, 1);
-
- // The master mode may now be entered by setting the STA bit
- // this will generate a start condition when the bus becomes free
- i2c_conset(obj, 1, 0, 0, 1);
-
- i2c_wait_SI(obj);
- status = i2c_status(obj);
-
- // Clear start bit now transmitted, and interrupt bit
- i2c_conclr(obj, 1, 0, 0, 0);
- return status;
-}
-
-inline int i2c_stop(i2c_t *obj) {
- int timeout = 0;
-
- // write the stop bit
- i2c_conset(obj, 0, 1, 0, 0);
- i2c_clear_SI(obj);
-
- // wait for STO bit to reset
- while(I2C_CONSET(obj) & (1 << 4)) {
- 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
- I2C_DAT(obj) = value;
-
- // clear SI to init a send
- i2c_clear_SI(obj);
-
- // wait and return status
- i2c_wait_SI(obj);
- return i2c_status(obj);
-}
-
-static inline int i2c_do_read(i2c_t *obj, int last) {
- // we are in state 0x40 (SLA+R tx'd) or 0x50 (data rx'd and ack)
- if(last) {
- i2c_conclr(obj, 0, 0, 0, 1); // send a NOT ACK
- } else {
- i2c_conset(obj, 0, 0, 0, 1); // send a ACK
- }
-
- // accept byte
- i2c_clear_SI(obj);
-
- // wait for it to arrive
- i2c_wait_SI(obj);
-
- // return the data
- return (I2C_DAT(obj) & 0xFF);
-}
-
-void i2c_frequency(i2c_t *obj, int hz) {
- // [TODO] set pclk to /4
- uint32_t PCLK = SystemCoreClock / 4;
-
- uint32_t pulse = PCLK / (hz * 2);
-
- // I2C Rate
- I2C_SCLL(obj, pulse);
- I2C_SCLH(obj, pulse);
-}
-
-// The I2C does a read or a write as a whole operation
-// There are two types of error conditions it can encounter
-// 1) it can not obtain the bus
-// 2) it gets error responses at part of the transmission
-//
-// We tackle them as follows:
-// 1) we retry until we get the bus. we could have a "timeout" if we can not get it
-// which basically turns it in to a 2)
-// 2) on error, we use the standard error mechanisms to report/debug
-//
-// Therefore an I2C transaction should always complete. If it doesn't it is usually
-// because something is setup wrong (e.g. wiring), and we don't need to programatically
-// check for that
-
-int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) {
- int count, status;
-
- status = i2c_start(obj);
-
- if ((status != 0x10) && (status != 0x08)) {
- i2c_stop(obj);
- return I2C_ERROR_BUS_BUSY;
- }
-
- status = i2c_do_write(obj, (address | 0x01), 1);
- if (status != 0x40) {
- i2c_stop(obj);
- return I2C_ERROR_NO_SLAVE;
- }
-
- // Read in all except last byte
- for (count = 0; count < (length - 1); count++) {
- int value = i2c_do_read(obj, 0);
- status = i2c_status(obj);
- if (status != 0x50) {
- i2c_stop(obj);
- return count;
- }
- data[count] = (char) value;
- }
-
- // read in last byte
- int value = i2c_do_read(obj, 1);
- status = i2c_status(obj);
- if (status != 0x58) {
- i2c_stop(obj);
- return length - 1;
- }
-
- data[count] = (char) value;
-
- // If not repeated start, send stop.
- if (stop) {
- i2c_stop(obj);
- }
-
- return length;
-}
-
-int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop) {
- int i, status;
-
- status = i2c_start(obj);
-
- if ((status != 0x10) && (status != 0x08)) {
- i2c_stop(obj);
- return I2C_ERROR_BUS_BUSY;
- }
-
- status = i2c_do_write(obj, (address & 0xFE), 1);
- if (status != 0x18) {
- i2c_stop(obj);
- return I2C_ERROR_NO_SLAVE;
- }
-
- for (i=0; i<length; i++) {
- status = i2c_do_write(obj, data[i], 0);
- if(status != 0x28) {
- i2c_stop(obj);
- return i;
- }
- }
-
- // clearing the serial interrupt here might cause an unintended rewrite of the last byte
- // see also issue report https://mbed.org/users/mbed_official/code/mbed/issues/1
- // i2c_clear_SI(obj);
-
- // If not repeated start, send stop.
- if (stop) {
- i2c_stop(obj);
- }
-
- 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) {
- int ack;
- int status = i2c_do_write(obj, (data & 0xFF), 0);
-
- switch(status) {
- case 0x18: case 0x28: // Master transmit ACKs
- ack = 1;
- break;
- case 0x40: // Master receive address transmitted ACK
- ack = 1;
- break;
- case 0xB8: // Slave transmit ACK
- ack = 1;
- break;
- default:
- ack = 0;
- break;
- }
-
- return ack;
-}
-
-void i2c_slave_mode(i2c_t *obj, int enable_slave) {
- if (enable_slave != 0) {
- i2c_conclr(obj, 1, 1, 1, 0);
- i2c_conset(obj, 0, 0, 0, 1);
- } else {
- i2c_conclr(obj, 1, 1, 1, 1);
- }
-}
-
-int i2c_slave_receive(i2c_t *obj) {
- int status;
- int retval;
-
- status = i2c_status(obj);
- switch(status) {
- case 0x60: retval = 3; break;
- case 0x70: retval = 2; break;
- case 0xA8: retval = 1; break;
- default : retval = 0; break;
- }
-
- return(retval);
-}
-
-int i2c_slave_read(i2c_t *obj, char *data, int length) {
- int count = 0;
- int status;
-
- do {
- i2c_clear_SI(obj);
- i2c_wait_SI(obj);
- status = i2c_status(obj);
- if((status == 0x80) || (status == 0x90)) {
- data[count] = I2C_DAT(obj) & 0xFF;
- }
- count++;
- } while (((status == 0x80) || (status == 0x90) ||
- (status == 0x060) || (status == 0x70)) && (count < length));
-
- if(status != 0xA0) {
- i2c_stop(obj);
- }
-
- i2c_clear_SI(obj);
-
- return count;
-}
-
-int i2c_slave_write(i2c_t *obj, const char *data, int length) {
- int count = 0;
- int status;
-
- if(length <= 0) {
- return(0);
- }
-
- do {
- status = i2c_do_write(obj, data[count], 0);
- count++;
- } while ((count < length) && (status == 0xB8));
-
- if ((status != 0xC0) && (status != 0xC8)) {
- i2c_stop(obj);
- }
-
- i2c_clear_SI(obj);
-
- return(count);
-}
-
-void i2c_slave_address(i2c_t *obj, int idx, uint32_t address, uint32_t mask) {
- uint32_t addr;
-
- if ((idx >= 0) && (idx <= 3)) {
- addr = ((uint32_t)obj->i2c) + I2C_addr_offset[0][idx];
- *((uint32_t *) addr) = address & 0xFF;
- addr = ((uint32_t)obj->i2c) + I2C_addr_offset[1][idx];
- *((uint32_t *) addr) = mask & 0xFE;
- }
-}
projects / qmk_firmware.git / blobdiff