/**************************************************************************** * drivers/sensors/as5048a.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you 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. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #if defined(CONFIG_SENSORS_AS5048A) /**************************************************************************** * Private Types ****************************************************************************/ struct as5048a_dev_s { struct qe_lowerhalf_s lower; /* AS5048A quadrature encoder lower half */ FAR struct spi_dev_s *spi; /* SPI interface */ /* Since multiple AS5048A can be connected to the same SPI bus we need * to use multiple spi device ids which are employed by NuttX to select/ * deselect the desired AS5048A chip via their chip select inputs. */ int spi_devid; }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ static int as5048a_writeu16(FAR struct as5048a_dev_s *priv, uint16_t regaddr, uint16_t regval); static int as5048a_exchange(FAR struct as5048a_dev_s *priv, uint16_t regaddr, FAR uint16_t *regval); static uint16_t calc_even_parity(uint16_t value); static int as5048a_readzero(FAR struct as5048a_dev_s *priv, FAR uint16_t *zero); static int as5048a_writezero(FAR struct as5048a_dev_s *priv, uint16_t zero); static int as5048a_readagc(FAR struct as5048a_dev_s *priv, FAR uint16_t *agc); static int as5048a_readdiag(FAR struct as5048a_dev_s *priv, FAR uint16_t *diag); static int as5048a_readmag(FAR struct as5048a_dev_s *priv, FAR uint16_t *mag); static int as5048a_readang(FAR struct as5048a_dev_s *priv, FAR uint16_t *ang); /* Character Driver Methods */ static int as5048a_setup(FAR struct qe_lowerhalf_s *lower); static int as5048a_shutdown(FAR struct qe_lowerhalf_s *lower); static int as5048a_position(FAR struct qe_lowerhalf_s *lower, FAR int32_t *pos); static int as5048a_reset(FAR struct qe_lowerhalf_s *lower); static int as5048a_ioctl(FAR struct qe_lowerhalf_s *lower, int cmd, unsigned long arg); /**************************************************************************** * Private Data ****************************************************************************/ static const struct qe_ops_s g_qeops = { as5048a_setup, /* setup */ as5048a_shutdown, /* shutdown */ as5048a_position, /* position */ NULL, /* setposmax */ as5048a_reset, /* reset */ NULL, /* setindex */ as5048a_ioctl /* ioctl */ }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: as5048a_configspi * * Description: * ****************************************************************************/ static inline void as5048a_configspi(FAR struct spi_dev_s *spi) { /* Configure SPI for the AS5048A */ SPI_SETMODE(spi, AS5048A_SPI_MODE); SPI_SETBITS(spi, 16); SPI_HWFEATURES(spi, 0); SPI_SETFREQUENCY(spi, AS5048A_SPI_MAXFREQUENCY); } /**************************************************************************** * Name: as5048a_writeu16 * * Description: * Write to two 8-bit registers * ****************************************************************************/ static int as5048a_writeu16(FAR struct as5048a_dev_s *priv, uint16_t regaddr, uint16_t regval) { uint16_t datout; /* If SPI bus is shared then lock and configure it */ SPI_LOCK(priv->spi, true); as5048a_configspi(priv->spi); /* Select the AS5048A */ SPI_SELECT(priv->spi, priv->spi_devid, true); /* Send register address and set the value */ datout = AS5048A_CMD_WRITE | regaddr; datout |= calc_even_parity(datout) << 15; SPI_SEND(priv->spi, datout); datout = 0x3fff & regval; datout |= calc_even_parity(datout) << 15; SPI_SEND(priv->spi, datout); /* Send NOP command */ SPI_SEND(priv->spi, 0x0000); /* Deselect the AS5048A */ SPI_SELECT(priv->spi, priv->spi_devid, false); /* Unlock bus */ SPI_LOCK(priv->spi, false); return OK; } /**************************************************************************** * Name: as5048a_exchange * * Description: * Read from 16-bit registers * ****************************************************************************/ static int as5048a_exchange(FAR struct as5048a_dev_s *priv, uint16_t regaddr, FAR uint16_t *regval) { uint16_t ret; uint16_t dat; uint16_t temp; /* If SPI bus is shared then lock and configure it */ SPI_LOCK(priv->spi, true); as5048a_configspi(priv->spi); /* Select the AS5048A */ SPI_SELECT(priv->spi, priv->spi_devid, true); /* Send READ command. Received data is thrown away * this data comes from the previous command (unknown) */ dat = AS5048A_CMD_READ | regaddr; dat |= calc_even_parity(dat) << 15; /* Send register to read and get the next byte */ SPI_SEND(priv->spi, dat); /* Send NOP command. Received data is the value of regaddr * from the previous command */ dat = 0x0000; /* NOP command */ temp = SPI_SEND(priv->spi, dat); if (temp & 0x4000) { /* error flag set - need to reset it */ dat = AS5048A_CMD_READ | AS5048A_CLRERR_REG; dat |= calc_even_parity(dat) << 15; SPI_SEND(priv->spi, dat); snerr("ERROR: as5048a error flag set, need to reset it! %02x\n", temp); ret = -1; } else { *regval = temp; ret = 0; } /* Deselect the AS5048A */ SPI_SELECT(priv->spi, priv->spi_devid, false); /* Unlock bus */ SPI_LOCK(priv->spi, false); sninfo("addr: %02x value: %02x ret: %d\n", regaddr, *regval, ret); return ret; } /**************************************************************************** * Name: calc_even_parity * * Description: * get the even parity of input value * ****************************************************************************/ static uint16_t calc_even_parity(uint16_t value) { uint16_t cnt = 0; uint8_t i; for (i = 0; i < 16; i++) { if (value & 0x1) cnt++; value >>= 1; } return cnt & 0x1; } /**************************************************************************** * Name: as5048a_readzero * * Description: * Read from the zero position registers * ****************************************************************************/ static int as5048a_readzero(FAR struct as5048a_dev_s *priv, FAR uint16_t *zero) { uint16_t hi; uint16_t lo; int ret; /* Read the high 8 bits of the 13-bit value */ ret = as5048a_exchange(priv, AS5048A_ZEROHI_REG, &hi); if (ret < 0) { snerr("ERROR: as5048a_readu8 failed: %d\n", ret); return ret; } /* Read the low 5 bits of the 13-bit value */ ret = as5048a_exchange(priv, AS5048A_ZEROLO_REG, &lo); if (ret < 0) { snerr("ERROR: as5048a_readu8 failed: %d\n", ret); return ret; } *zero = (uint16_t)hi << 6 | (uint16_t)lo; sninfo("zero: %04x ret: %d\n", *zero, ret); return ret; } /**************************************************************************** * Name: as5048a_writezero * * Description: * Write to the zero position registers * ****************************************************************************/ static int as5048a_writezero(FAR struct as5048a_dev_s *priv, uint16_t zero) { int ret; sninfo("zero: %04x\n", zero); ret = as5048a_writeu16(priv, AS5048A_ZEROHI_REG, (zero >> 6)); if (ret < 0) { snerr("ERROR: as5048a_writeu16 failed: %d\n", ret); } ret = as5048a_writeu16(priv, AS5048A_ZEROLO_REG, zero); if (ret < 0) { snerr("ERROR: as5048a_writeu16 failed: %d\n", ret); } return ret; } /**************************************************************************** * Name: as5048a_readagc * * Description: * Read from the automatic gain control register * ****************************************************************************/ static int as5048a_readagc(FAR struct as5048a_dev_s *priv, FAR uint16_t *agc) { int ret; ret = as5048a_exchange(priv, AS5048A_AGC_REG, agc); if (ret < 0) { snerr("ERROR: as5048a_exchange failed: %d\n", ret); return ret; } sninfo("agc: %02x ret: %d\n", *agc, ret); return ret; } /**************************************************************************** * Name: as5048a_readdiag * * Description: * Read from the diagnostics register * ****************************************************************************/ static int as5048a_readdiag(FAR struct as5048a_dev_s *priv, FAR uint16_t *diag) { int ret; ret = as5048a_exchange(priv, AS5048A_DIAG_REG, diag); if (ret < 0) { snerr("ERROR: as5048a_exchange failed: %d\n", ret); return ret; } sninfo("diag: %02x ret: %d\n", *diag, ret); return ret; } /**************************************************************************** * Name: as5048a_readmag * * Description: * Read from the magnitude registers * ****************************************************************************/ static int as5048a_readmag(FAR struct as5048a_dev_s *priv, FAR uint16_t *mag) { int ret; ret = as5048a_exchange(priv, AS5048A_MAG_REG, mag); if (ret < 0) { snerr("ERROR: as5048a_exchange failed: %d\n", ret); return ret; } sninfo("mag: %04x ret: %d\n", *mag, ret); return ret; } /**************************************************************************** * Name: as5048a_readang * * Description: * Read from the angle registers * ****************************************************************************/ static int as5048a_readang(FAR struct as5048a_dev_s *priv, FAR uint16_t *ang) { int ret; ret = as5048a_exchange(priv, AS5048A_ANGLE_REG, ang); if (ret < 0) { snerr("ERROR: as5048a_exchange failed: %d\n", ret); return ret; } sninfo("ang: %04x ret: %d\n", *ang, ret); return ret; } /**************************************************************************** * Name: as5048a_setup * * Description: * This method is called when the driver is opened * ****************************************************************************/ static int as5048a_setup(FAR struct qe_lowerhalf_s *lower) { return OK; } /**************************************************************************** * Name: as5048a_shutdown * * Description: * This method is called when the driver is closed * ****************************************************************************/ static int as5048a_shutdown(FAR struct qe_lowerhalf_s *lower) { return OK; } /**************************************************************************** * Name: as5048a_position * * Description: * Return the current position measurement * ****************************************************************************/ static int as5048a_position(FAR struct qe_lowerhalf_s *lower, FAR int32_t *pos) { FAR struct as5048a_dev_s *priv = (FAR struct as5048a_dev_s *)lower; uint16_t ang; int ret; ret = as5048a_readang(priv, &ang); if (ret < 0) { snerr("ERROR: as5048a_readang failed: %d\n", ret); return ret; } *pos = (int32_t)ang; return ret; } /**************************************************************************** * Name: as5048a_reset * * Description: * Reset the position measurement to zero * ****************************************************************************/ static int as5048a_reset(FAR struct qe_lowerhalf_s *lower) { FAR struct as5048a_dev_s *priv = (FAR struct as5048a_dev_s *)lower; uint16_t ang; int ret; ret = as5048a_writezero(priv, 0); if (ret < 0) { snerr("ERROR: as5048a_writezero failed: %d\n", ret); return ret; } ret = as5048a_readang(priv, &ang); if (ret < 0) { snerr("ERROR: as5048a_readang failed: %d\n", ret); return ret; } ret = as5048a_writezero(priv, ang); if (ret < 0) { snerr("ERROR: as5048a_writezero failed: %d\n", ret); } return ret; } /**************************************************************************** * Name: as5048a_ioctl ****************************************************************************/ static int as5048a_ioctl(FAR struct qe_lowerhalf_s *lower, int cmd, unsigned long arg) { FAR struct as5048a_dev_s *priv = (FAR struct as5048a_dev_s *)lower; int ret = OK; switch (cmd) { /* Read from the zero position registers. Arg: int* pointer. */ case QEIOC_AS5048A_ZEROPOSITION: { FAR int *ptr = (FAR int *)((uintptr_t)arg); uint16_t zero; DEBUGASSERT(ptr != NULL); ret = as5048a_readzero(priv, &zero); if (ret == OK) { *ptr = (int)zero; } sninfo("zero: %04x ret: %d\n", *ptr, ret); } break; /* Read from the automatic gain control register */ case QEIOC_AS5048A_AUTOGAINCTL: { FAR uint16_t *ptr = (FAR uint16_t *)((uintptr_t)arg); DEBUGASSERT(ptr != NULL); ret = as5048a_readagc(priv, ptr); sninfo("agc: %02x ret: %d\n", *ptr, ret); } break; /* Read from the diagnostics register. Arg: uint8_t* pointer. */ case QEIOC_AS5048A_DIAGNOSTICS: { FAR uint16_t *ptr = (FAR uint16_t *)((uintptr_t)arg); DEBUGASSERT(ptr != NULL); ret = as5048a_readdiag(priv, ptr); sninfo("diag: %02x ret: %d\n", *ptr, ret); } break; /* Read from the magnitude registers. Arg: int* pointer. */ case QEIOC_AS5048A_MAGNITUDE: { FAR int *ptr = (FAR int *)((uintptr_t)arg); uint16_t mag; DEBUGASSERT(ptr != NULL); ret = as5048a_readmag(priv, &mag); if (ret == OK) { *ptr = (int)mag; } sninfo("mag: %04x ret: %d\n", *ptr, ret); } break; default: snerr("ERROR: Unrecognized cmd: %d arg: %ld\n", cmd, arg); ret = -ENOTTY; break; } return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: as5048a_initialize * * Description: * Initialize the AS5048A device. * * Input Parameters: * spi - An SPI driver instance. * * Returned Value: * A new lower half encoder interface for the AS5048A on success; * NULL on failure. * ****************************************************************************/ FAR struct qe_lowerhalf_s *as5048a_initialize(FAR struct spi_dev_s *spi, int spi_devid) { FAR struct as5048a_dev_s *priv; DEBUGASSERT(spi != NULL); /* Initialize the device's structure */ priv = (FAR struct as5048a_dev_s *)kmm_malloc(sizeof(*priv)); if (priv == NULL) { snerr("ERROR: Failed to allocate instance\n"); return NULL; } priv->lower.ops = &g_qeops; priv->spi = spi; priv->spi_devid = spi_devid; return &priv->lower; } #endif /* CONFIG_SENSORS_AS5048A */