diff options
Diffstat (limited to 'src/vlib/i2c.c')
| -rw-r--r-- | src/vlib/i2c.c | 231 |
1 files changed, 0 insertions, 231 deletions
diff --git a/src/vlib/i2c.c b/src/vlib/i2c.c deleted file mode 100644 index 97f5bb21cc7..00000000000 --- a/src/vlib/i2c.c +++ /dev/null @@ -1,231 +0,0 @@ -/* - * Copyright (c) 2016 Cisco and/or its affiliates. - * 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 <vlib/vlib.h> -#include <vlib/i2c.h> - -static inline void -i2c_delay (i2c_bus_t * b, f64 timeout) -{ - vlib_main_t *vm = vlib_get_main (); - vlib_time_wait (vm, timeout); -} - -static void -i2c_wait_for_scl (i2c_bus_t * b) -{ - f64 t = 0; - - while (t < b->hold_time) - { - int sda, scl; - i2c_delay (b, b->rise_fall_time); - b->get_bits (b, &scl, &sda); - - if (scl) - return; - - t += b->rise_fall_time; - } - b->timeout = 1; -} - -static void -i2c_start (i2c_bus_t * b) -{ - b->timeout = 0; - - b->put_bits (b, 1, 1); - i2c_wait_for_scl (b); - - if (vlib_i2c_bus_timed_out (b)) - return; - - b->put_bits (b, 1, 0); - i2c_delay (b, b->hold_time); - b->put_bits (b, 0, 0); - i2c_delay (b, b->hold_time); -} - -static void -i2c_stop (i2c_bus_t * b) -{ - b->put_bits (b, 0, 0); - i2c_delay (b, b->rise_fall_time); - - b->put_bits (b, 1, 0); - i2c_delay (b, b->hold_time); - - b->put_bits (b, 1, 1); - i2c_delay (b, b->hold_time); -} - -static void -i2c_write_bit (i2c_bus_t * b, int sda) -{ - b->put_bits (b, 0, sda); - i2c_delay (b, b->rise_fall_time); - - b->put_bits (b, 1, sda); - i2c_wait_for_scl (b); - i2c_delay (b, b->hold_time); - - b->put_bits (b, 0, sda); - i2c_delay (b, b->rise_fall_time); -} - -static void -i2c_read_bit (i2c_bus_t * b, int *sda) -{ - int scl; - - b->put_bits (b, 1, 1); - i2c_wait_for_scl (b); - i2c_delay (b, b->hold_time); - - b->get_bits (b, &scl, sda); - - b->put_bits (b, 0, 1); - i2c_delay (b, b->rise_fall_time); -} - -static void -i2c_write_byte (i2c_bus_t * b, u8 data) -{ - int i, sda; - - for (i = 7; i >= 0; i--) - { - i2c_write_bit (b, (data >> i) & 1); - if (b->timeout) - return; - } - - b->put_bits (b, 0, 1); - i2c_delay (b, b->rise_fall_time); - - i2c_read_bit (b, &sda); - - if (sda) - b->timeout = 1; -} - - -static void -i2c_read_byte (i2c_bus_t * b, u8 * data, int ack) -{ - int i, sda; - - *data = 0; - - b->put_bits (b, 0, 1); - i2c_delay (b, b->rise_fall_time); - - for (i = 7; i >= 0; i--) - { - i2c_read_bit (b, &sda); - if (b->timeout) - return; - - *data |= (sda != 0) << i; - } - - i2c_write_bit (b, ack == 0); -} - - -void -vlib_i2c_init (i2c_bus_t * b) -{ - f64 tick; - if (!b->clock) - b->clock = 400000; - - tick = 1.0 / b->clock; - - /* Spend 40% of time in low and high states */ - if (!b->hold_time) - b->hold_time = 0.4 * tick; - - /* Spend 10% of time waiting for rise and fall */ - if (!b->rise_fall_time) - b->rise_fall_time = 0.1 * tick; -} - -void -vlib_i2c_xfer (i2c_bus_t * bus, i2c_msg_t * msgs) -{ - i2c_msg_t *msg; - int i; - - vec_foreach (msg, msgs) - { - i2c_start (bus); - i2c_write_byte (bus, - (msg->addr << 1) + (msg->flags == I2C_MSG_FLAG_READ)); - - if (msg->flags & I2C_MSG_FLAG_READ) - for (i = 0; i < msg->len; i++) - { - i2c_read_byte (bus, &msg->buffer[i], /* ack */ i + 1 != msg->len); - if (bus->timeout) - goto done; - } - - else - for (i = 0; i < msg->len; i++) - { - i2c_write_byte (bus, msg->buffer[i]); - if (bus->timeout) - goto done; - } - } - -done: - i2c_stop (bus); -} - -void -vlib_i2c_read_eeprom (i2c_bus_t * bus, u8 i2c_addr, u16 start_addr, - u16 length, u8 * data) -{ - i2c_msg_t *msg = 0; - u8 start_address[1]; - - vec_validate (msg, 1); - - start_address[0] = start_addr; - msg[0].addr = i2c_addr; - msg[0].flags = I2C_MSG_FLAG_WRITE; - msg[0].buffer = (u8 *) & start_address; - msg[0].len = 1; - - msg[1].addr = i2c_addr; - msg[1].flags = I2C_MSG_FLAG_READ; - msg[1].buffer = data; - msg[1].len = length; - - vlib_i2c_xfer (bus, msg); - - vec_free (msg); -} - -/* - * fd.io coding-style-patch-verification: ON - * - * Local Variables: - * eval: (c-set-style "gnu") - * End: - */ |