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Diffstat (limited to 'keyboards/jj40/i2c.c')
| -rw-r--r-- | keyboards/jj40/i2c.c | 104 |
1 files changed, 0 insertions, 104 deletions
diff --git a/keyboards/jj40/i2c.c b/keyboards/jj40/i2c.c deleted file mode 100644 index c27f3e3d1..000000000 --- a/keyboards/jj40/i2c.c +++ /dev/null | |||
| @@ -1,104 +0,0 @@ | |||
| 1 | /* | ||
| 2 | Copyright 2016 Luiz Ribeiro <luizribeiro@gmail.com> | ||
| 3 | |||
| 4 | This program is free software: you can redistribute it and/or modify | ||
| 5 | it under the terms of the GNU General Public License as published by | ||
| 6 | the Free Software Foundation, either version 2 of the License, or | ||
| 7 | (at your option) any later version. | ||
| 8 | |||
| 9 | This program is distributed in the hope that it will be useful, | ||
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
| 12 | GNU General Public License for more details. | ||
| 13 | |||
| 14 | You should have received a copy of the GNU General Public License | ||
| 15 | along with this program. If not, see <http://www.gnu.org/licenses/>. | ||
| 16 | */ | ||
| 17 | |||
| 18 | #include <avr/io.h> | ||
| 19 | #include <util/twi.h> | ||
| 20 | |||
| 21 | #include "i2c.h" | ||
| 22 | |||
| 23 | void i2c_set_bitrate(uint16_t bitrate_khz) { | ||
| 24 | uint8_t bitrate_div = ((F_CPU / 1000l) / bitrate_khz); | ||
| 25 | if (bitrate_div >= 16) { | ||
| 26 | bitrate_div = (bitrate_div - 16) / 2; | ||
| 27 | } | ||
| 28 | TWBR = bitrate_div; | ||
| 29 | } | ||
| 30 | |||
| 31 | void i2c_init(void) { | ||
| 32 | // set pull-up resistors on I2C bus pins | ||
| 33 | PORTC |= 0b11; | ||
| 34 | |||
| 35 | i2c_set_bitrate(400); | ||
| 36 | |||
| 37 | // enable TWI (two-wire interface) | ||
| 38 | TWCR |= (1 << TWEN); | ||
| 39 | |||
| 40 | // enable TWI interrupt and slave address ACK | ||
| 41 | TWCR |= (1 << TWIE); | ||
| 42 | TWCR |= (1 << TWEA); | ||
| 43 | } | ||
| 44 | |||
| 45 | uint8_t i2c_start(uint8_t address) { | ||
| 46 | // reset TWI control register | ||
| 47 | TWCR = 0; | ||
| 48 | |||
| 49 | // begin transmission and wait for it to end | ||
| 50 | TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN); | ||
| 51 | while (!(TWCR & (1<<TWINT))); | ||
| 52 | |||
| 53 | // check if the start condition was successfully transmitted | ||
| 54 | if ((TWSR & 0xF8) != TW_START) { | ||
| 55 | return 1; | ||
| 56 | } | ||
| 57 | |||
| 58 | // transmit address and wait | ||
| 59 | TWDR = address; | ||
| 60 | TWCR = (1<<TWINT) | (1<<TWEN); | ||
| 61 | while (!(TWCR & (1<<TWINT))); | ||
| 62 | |||
| 63 | // check if the device has acknowledged the READ / WRITE mode | ||
| 64 | uint8_t twst = TW_STATUS & 0xF8; | ||
| 65 | if ((twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK)) { | ||
| 66 | return 1; | ||
| 67 | } | ||
| 68 | |||
| 69 | return 0; | ||
| 70 | } | ||
| 71 | |||
| 72 | void i2c_stop(void) { | ||
| 73 | TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO); | ||
| 74 | } | ||
| 75 | |||
| 76 | uint8_t i2c_write(uint8_t data) { | ||
| 77 | TWDR = data; | ||
| 78 | |||
| 79 | // transmit data and wait | ||
| 80 | TWCR = (1<<TWINT) | (1<<TWEN); | ||
| 81 | while (!(TWCR & (1<<TWINT))); | ||
| 82 | |||
| 83 | if ((TWSR & 0xF8) != TW_MT_DATA_ACK) { | ||
| 84 | return 1; | ||
| 85 | } | ||
| 86 | |||
| 87 | return 0; | ||
| 88 | } | ||
| 89 | |||
| 90 | uint8_t i2c_send(uint8_t address, uint8_t *data, uint16_t length) { | ||
| 91 | if (i2c_start(address)) { | ||
| 92 | return 1; | ||
| 93 | } | ||
| 94 | |||
| 95 | for (uint16_t i = 0; i < length; i++) { | ||
| 96 | if (i2c_write(data[i])) { | ||
| 97 | return 1; | ||
| 98 | } | ||
| 99 | } | ||
| 100 | |||
| 101 | i2c_stop(); | ||
| 102 | |||
| 103 | return 0; | ||
| 104 | } | ||
