diff options
Diffstat (limited to 'cpukit/dev/i2c/ti-tmp112.c')
| -rw-r--r-- | cpukit/dev/i2c/ti-tmp112.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/cpukit/dev/i2c/ti-tmp112.c b/cpukit/dev/i2c/ti-tmp112.c new file mode 100644 index 0000000000..0886a4de9c --- /dev/null +++ b/cpukit/dev/i2c/ti-tmp112.c @@ -0,0 +1,229 @@ +/* + * Copyright (c) 2016-2017 Chris Johns <chrisj@rtems.org> + * All rights reserved. + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + +#if HAVE_CONFIG_H + #include "config.h" +#endif + +#include <stdio.h> + +#include <dev/i2c/i2c.h> +#include <dev/i2c/ti-tmp112.h> + +/* + * Registers. + */ +#define TMP_TEMPERATURE (0) +#define TMP_CONFIG (1) +#define TMP_LOW_TEMP (2) +#define TMP_HIGH_TEMP (3) + +/* + * Configuration register. + */ +#define CFG_ONE_SHOT_BASE (15) +#define CFG_SHUTDOWN_BASE (8) +#define CFG_EXTENDED_MODE_BASE (4) + +#define CFG_ONE_SHOT (1 << CFG_ONE_SHOT_BASE) +#define CFG_SHUTDOWN (1 << CFG_SHUTDOWN_BASE) +#define CFG_EXTENDED_MODE (1 << CFG_EXTENDED_MODE_BASE) + +typedef struct { + i2c_dev base; + uint8_t pointer; + uint16_t config_shadow; +} ti_tmp112; + +static int +ti_tmp112_reg_write(ti_tmp112* dev, int reg, uint16_t value) +{ + uint8_t out[3]; + i2c_msg msgs[1] = { + { + .addr = dev->base.address, + .flags = 0, + .len = (uint16_t) sizeof(out), + .buf = &out[0] + } + }; + int err; + if (dev->pointer == reg) { + out[0] = (uint8_t) (value >> 8); + out[1] = (uint8_t) value; + msgs[0].len = 2; + } + else { + out[0] = reg; + out[1] = (uint8_t) (value >> 8); + out[2] = (uint8_t) value; + } + err = i2c_bus_transfer(dev->base.bus, &msgs[0], RTEMS_ARRAY_SIZE(msgs)); + if (err == 0) + dev->pointer = reg; + else + dev->pointer = -1; + return err; +} + +static int +ti_tmp112_reg_read(ti_tmp112* dev, int reg, uint16_t* value) +{ + uint8_t in[2] = { 0, 0 }; + int err; + if (dev->pointer == reg) { + i2c_msg msgs[1] = { + { + .addr = dev->base.address, + .flags = I2C_M_RD, + .len = (uint16_t) sizeof(in), + .buf = &in[0] + } + }; + err = i2c_bus_transfer(dev->base.bus, &msgs[0], RTEMS_ARRAY_SIZE(msgs)); + } + else { + uint8_t out[1] = { (uint8_t) reg }; + i2c_msg msgs[2] = { + { + .addr = dev->base.address, + .flags = 0, + .len = (uint16_t) sizeof(out), + .buf = &out[0] + }, { + .addr = dev->base.address, + .flags = I2C_M_RD, + .len = (uint16_t) sizeof(in), + .buf = &in[0] + } + }; + err = i2c_bus_transfer(dev->base.bus, &msgs[0], RTEMS_ARRAY_SIZE(msgs)); + if (err == 0) + dev->pointer = reg; + else + dev->pointer = -1; + } + *value = (((uint16_t) in[0]) << 8) | in[1]; + return err; +} + +static int +ti_tmp112_set_config(ti_tmp112* dev, uint16_t value) +{ + int err; + dev->config_shadow = value; + err = ti_tmp112_reg_write(dev, TMP_CONFIG, dev->config_shadow); + return err; +} + +static int +ti_tmp112_get_temp(ti_tmp112* dev, int* temp, bool raw) +{ + uint16_t value = 0; + int err; + + *temp = 0; + + if ((dev->config_shadow & CFG_SHUTDOWN) == CFG_SHUTDOWN) { + i2c_bus_obtain(dev->base.bus); + err = ti_tmp112_reg_write(dev, + TMP_CONFIG, + dev->config_shadow | CFG_ONE_SHOT); + if (err == 0) { + uint16_t config = 0; + while (err == 0 && (config & CFG_ONE_SHOT) == 0) + err = ti_tmp112_reg_read(dev, TMP_CONFIG, &config); + err = ti_tmp112_reg_read(dev, TMP_TEMPERATURE, &value); + } + i2c_bus_release(dev->base.bus); + } + else { + err = ti_tmp112_reg_read(dev, TMP_TEMPERATURE, &value); + } + + if (err == 0) { + if (raw) { + *temp = (int) value; + } + else { + int bits = 12; + uint32_t u; + if ((dev->config_shadow & CFG_EXTENDED_MODE) != 0) + bits = 13; + u = value >> ((sizeof(value) * 8) - bits); + *temp = (int) (u & ((1 << bits) - 1)); + if ((u & (1 << (bits - 1))) != 0) + *temp |= ~((1 << bits) - 1); + *temp = *temp * 625; + } + } + + return err; +} + +static int +ti_tmp112_ioctl(i2c_dev* iic_dev, ioctl_command_t command, void* arg) +{ + ti_tmp112* dev = (ti_tmp112*) iic_dev; + uint16_t v16; + int vint; + int err; + + switch (command) { + case TI_TMP112_GET_TEMP: + vint = 0; + err = ti_tmp112_get_temp(dev, &vint, false); + if (err == 0) + *((int*) arg) = vint; + break; + case TI_TMP112_GET_TEMP_RAW: + vint = 0; + err = ti_tmp112_get_temp(dev, &vint, true); + if (err == 0) + *((uint16_t*) arg) = (uint16_t) vint; + break; + case TI_TMP112_SET_CONFIG: + v16 = (uint16_t)(uintptr_t) arg; + err = ti_tmp112_set_config(dev, v16); + break; + case TI_TMP112_SET_LOW_TEMP: + v16 = (uint16_t)(uintptr_t) arg; + err = ti_tmp112_reg_write(dev, TMP_LOW_TEMP, v16); + break; + case TI_TMP112_SET_HIGH_TEMP: + v16 = (uint16_t)(uintptr_t) arg; + err = ti_tmp112_reg_write(dev, TMP_HIGH_TEMP, v16); + break; + default: + err = -ENOTTY; + break; + } + + return err; +} + +int +i2c_dev_register_ti_tmp112(const char* bus_path, + const char* dev_path, + uint16_t address) +{ + ti_tmp112* dev; + + dev = (ti_tmp112*) + i2c_dev_alloc_and_init(sizeof(*dev), bus_path, address); + if (dev == NULL) { + return -1; + } + + dev->base.ioctl = ti_tmp112_ioctl; + dev->pointer = -1; + dev->config_shadow = 0x60a0; + + return i2c_dev_register(&dev->base, dev_path); +} |