i2c.c

/**
 * @section License
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2014-2017, Erik Moqvist
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * This file is part of the Simba project.
 */

#include "simba.h"

#if CONFIG_I2C == 1

struct module_t {
    int initialized;
#if CONFIG_FS_CMD_I2C_READ == 1
    struct fs_command_t cmd_read;
#endif
#if CONFIG_FS_CMD_I2C_WRITE == 1
    struct fs_command_t cmd_write;
#endif
};

#if CONFIG_SOFTWARE_I2C == 1
#    include "ports/software/i2c_port.i"
#else
#    include "i2c_port.i"
#endif

static struct module_t module;

#if CONFIG_FS_CMD_I2C_READ == 1

static int cmd_read_cb(int argc,
                       const char *argv[],
                       void *chout_p,
                       void *chin_p,
                       void *arg_p,
                       void *call_arg_p)
{
    struct i2c_driver_t i2c;
    long value;
    int slave_address;
    uint8_t data;

    if (argc != 2) {
        std_printf(OSTR("Usage: read <slave address>\r\n"));

        return (-EINVAL);
    }

    if (std_strtol(argv[1], &value) == NULL) {
        std_printf(OSTR("Bad slave address.\r\n"));

        return (-EINVAL);
    }

    slave_address = value;

    i2c_init(&i2c, &i2c_device[0], I2C_BAUDRATE_100KBPS, -1);
    i2c_start(&i2c);

    if (i2c_read(&i2c, slave_address, &data, 1) != 1) {
        std_printf(OSTR("Failed to read from slave device 0x%02x.\r\n"),
                   slave_address);
        goto out;
    }

    std_printf(OSTR("0x%02x\r\n"), data);

 out:
    i2c_stop(&i2c);

    return (0);
}

#endif

#if CONFIG_FS_CMD_I2C_WRITE == 1

static int cmd_write_cb(int argc,
                        const char *argv[],
                        void *chout_p,
                        void *chin_p,
                        void *arg_p,
                        void *call_arg_p)
{
    struct i2c_driver_t i2c;
    long value;
    int slave_address;
    uint8_t data;

    if (argc != 3) {
        std_printf(OSTR("Usage: write <slave address> <data byte>\r\n"));

        return (-EINVAL);
    }

    if (std_strtol(argv[1], &value) == NULL) {
        std_printf(OSTR("Bad slave address.\r\n"));

        return (-EINVAL);
    }

    slave_address = value;

    if (std_strtol(argv[2], &value) == NULL) {
        std_printf(OSTR("Bad data value.\r\n"));

        return (-EINVAL);
    }

    if ((value > 255) || (value < 0)) {
        std_printf(OSTR("Data byte value out of range.\r\n"));

        return (-EINVAL);
    }

    data = value;

    i2c_init(&i2c, &i2c_device[0], I2C_BAUDRATE_100KBPS, -1);
    i2c_start(&i2c);

    if (i2c_write(&i2c, slave_address, &data, 1) != 1) {
        std_printf(OSTR("Failed to write data 0x%02x to slave"
                         " device 0x%02x.\r\n"),
                   data,
                   slave_address);
    }

    i2c_stop(&i2c);

    return (0);
}

#endif

int i2c_module_init()
{
    /* Return immediately if the module is already initialized. */
    if (module.initialized == 1) {
        return (0);
    }

    module.initialized = 1;

#if CONFIG_FS_CMD_I2C_READ == 1

    fs_command_init(&module.cmd_read,
                    CSTR("/drivers/i2c/read"),
                    cmd_read_cb,
                    NULL);
    fs_command_register(&module.cmd_read);

#endif

#if CONFIG_FS_CMD_I2C_WRITE == 1

    fs_command_init(&module.cmd_write,
                    CSTR("/drivers/i2c/write"),
                    cmd_write_cb,
                    NULL);
    fs_command_register(&module.cmd_write);

#endif

    return (i2c_port_module_init());
}

int i2c_init(struct i2c_driver_t *self_p,
             struct i2c_device_t *dev_p,
             int baudrate,
             int address)
{
    ASSERTN(self_p != NULL, EINVAL);
    ASSERTN(dev_p != NULL, EINVAL);

    return (i2c_port_init(self_p, dev_p, baudrate, address));
}

int i2c_start(struct i2c_driver_t *self_p)
{
    ASSERTN(self_p != NULL, EINVAL);

    return (i2c_port_start(self_p));
}

int i2c_stop(struct i2c_driver_t *self_p)
{
    ASSERTN(self_p != NULL, EINVAL);

    return (i2c_port_stop(self_p));
}

ssize_t i2c_read(struct i2c_driver_t *self_p,
                 int address,
                 void *buf_p,
                 size_t size)
{
    ASSERTN(self_p != NULL, EINVAL);
    ASSERTN(address < 128, EINVAL);
    ASSERTN(buf_p != NULL, EINVAL);
    ASSERTN(size > 0, EINVAL);

    return (i2c_port_read(self_p, address, buf_p, size));
}

ssize_t i2c_write(struct i2c_driver_t *self_p,
                  int address,
                  const void *buf_p,
                  size_t size)
{
    ASSERTN(self_p != NULL, EINVAL);
    ASSERTN(address < 128, EINVAL);
    ASSERTN(buf_p != NULL, EINVAL);
    ASSERTN(size > 0, EINVAL);

    return (i2c_port_write(self_p, address, buf_p, size));
}

int i2c_scan(struct i2c_driver_t *self_p, int address)
{
    ASSERTN(self_p != NULL, EINVAL);
    ASSERTN(address < 128, EINVAL);

    return (i2c_port_scan(self_p, address));
}

int i2c_slave_start(struct i2c_driver_t *self_p)
{
    ASSERTN(self_p != NULL, EINVAL);

    return (i2c_port_slave_start(self_p));
}

int i2c_slave_stop(struct i2c_driver_t *self_p)
{
    ASSERTN(self_p != NULL, EINVAL);

    return (i2c_port_slave_stop(self_p));
}

ssize_t i2c_slave_read(struct i2c_driver_t *self_p,
                       void *buf_p,
                       size_t size)
{
    ASSERTN(self_p != NULL, EINVAL);
    ASSERTN(buf_p != NULL, EINVAL);
    ASSERTN(size > 0, EINVAL);

    return (i2c_port_slave_read(self_p, buf_p, size));
}

ssize_t i2c_slave_write(struct i2c_driver_t *self_p,
                        const void *buf_p,
                        size_t size)
{
    ASSERTN(self_p != NULL, EINVAL);
    ASSERTN(buf_p != NULL, EINVAL);
    ASSERTN(size > 0, EINVAL);

    return (i2c_port_slave_write(self_p, buf_p, size));
}

#endif