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incubator-nuttx/drivers/analog/mcp48xx.c

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/****************************************************************************
* drivers/analog/mcp48xx.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 <nuttx/config.h>
#include <stdio.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/arch.h>
#include <nuttx/analog/dac.h>
#include <nuttx/spi/spi.h>
#include <nuttx/analog/mcp48xx.h>
/****************************************************************************
* Preprocessor definitions
****************************************************************************/
#if !defined(CONFIG_SPI)
# error SPI Support Required.
#endif
#if defined(CONFIG_MCP48XX)
#if defined(CONFIG_MCP4802)
# define MCP48XX_DATA_BITS 8u
#elif defined(CONFIG_MCP4812)
# define MCP48XX_DATA_BITS 10u
#elif defined(CONFIG_MCP4822)
# define MCP48XX_DATA_BITS 12u
#else
# error MCP48XX variant selection required
#endif
#ifndef CONFIG_MCP48XX_SPI_FREQUENCY
# define CONFIG_MCP48XX_SPI_FREQUENCY 4000000
#endif
#define MCP48XX_SPI_MODE (SPIDEV_MODE0) /* SPI Mode 0: CPOL=0 CPHA=0 */
#define MCP48XX_MAX_CHANNELS 2u
#define MCP48XX_SHDN (1u << 12) /* Output Shutdown Control bit */
#define MCP48XX_GA (1u << 13) /* Output Gain Selection bit */
#define MCP48XX_MAX_BITS 12u
#define MCP48XX_DATA_MASK ((1u << MCP48XX_DATA_BITS) - 1u)
#define MCP48XX_DATA_SHIFT (MCP48XX_MAX_BITS - MCP48XX_DATA_BITS)
/****************************************************************************
* Private Types
****************************************************************************/
struct mcp48xx_dev_s
{
FAR struct spi_dev_s *spi; /* SPI interface */
uint32_t spidev; /* SPI Chip Select number */
uint16_t cmd[MCP48XX_MAX_CHANNELS]; /* Output Gain Selection and Output
* Shutdown Control bits */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* DAC methods */
static void mcp48xx_reset(FAR struct dac_dev_s *dev);
static int mcp48xx_setup(FAR struct dac_dev_s *dev);
static void mcp48xx_shutdown(FAR struct dac_dev_s *dev);
static void mcp48xx_txint(FAR struct dac_dev_s *dev, bool enable);
static int mcp48xx_send(FAR struct dac_dev_s *dev,
FAR struct dac_msg_s *msg);
static int mcp48xx_ioctl(FAR struct dac_dev_s *dev, int cmd,
unsigned long arg);
/****************************************************************************
* Private Data
****************************************************************************/
static struct mcp48xx_dev_s g_devpriv;
static const struct dac_ops_s g_dacops =
{
mcp48xx_reset, /* ao_reset */
mcp48xx_setup, /* ao_setup */
mcp48xx_shutdown, /* ao_shutdown */
mcp48xx_txint, /* ao_txint */
mcp48xx_send, /* ao_send */
mcp48xx_ioctl /* ao_ioctl */
};
static struct dac_dev_s g_dacdev =
{
&g_dacops, /* ad_ops */
&g_devpriv /* ad_priv */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: mcp48xx_configspi
*
* Description:
* Configure the SPI interface
*
****************************************************************************/
static inline void mcp48xx_configspi(FAR struct spi_dev_s *spi)
{
SPI_SETMODE(spi, MCP48XX_SPI_MODE);
SPI_SETBITS(spi, 8);
SPI_HWFEATURES(spi, 0);
SPI_SETFREQUENCY(spi, CONFIG_MCP48XX_SPI_FREQUENCY);
}
/****************************************************************************
* Name: mcp48xx_reset
*
* Description:
* Reset the DAC device. Called early to initialize the hardware. This
* is called, before ao_setup() and on error conditions.
*
****************************************************************************/
static void mcp48xx_reset(FAR struct dac_dev_s *dev)
{
}
/****************************************************************************
* Name: mcp48xx_setup
*
* Description:
* Configure the DAC. This method is called the first time that the DAC
* device is opened. This will occur when the port is first opened. This
* setup includes configuring and attaching DAC interrupts. Interrupts are
* all disabled upon return.
*
****************************************************************************/
static int mcp48xx_setup(FAR struct dac_dev_s *dev)
{
return OK;
}
/****************************************************************************
* Name: mcp48xx_shutdown
*
* Description:
* Disable the DAC. This method is called when the DAC device is closed.
* This method reverses the operation the setup method.
*
****************************************************************************/
static void mcp48xx_shutdown(FAR struct dac_dev_s *dev)
{
}
/****************************************************************************
* Name: mcp48xx_txint
*
* Description:
* Call to enable or disable TX interrupts
*
****************************************************************************/
static void mcp48xx_txint(FAR struct dac_dev_s *dev, bool enable)
{
}
/****************************************************************************
* Name: mcp48xx_send
****************************************************************************/
static int mcp48xx_send(FAR struct dac_dev_s *dev, FAR struct dac_msg_s *msg)
{
FAR struct mcp48xx_dev_s *priv = (FAR struct mcp48xx_dev_s *)dev->ad_priv;
uint16_t data;
/* Sanity check */
DEBUGASSERT(priv->spi != NULL);
/* Set up message to send */
ainfo("value: %08"PRIx32"\n", msg->am_data);
SPI_LOCK(priv->spi, true);
mcp48xx_configspi(priv->spi);
data = ((msg->am_data & MCP48XX_DATA_MASK) << MCP48XX_DATA_SHIFT)
| ((msg->am_channel & 0x01) << 15)
| priv->cmd[msg->am_channel & 0x01];
SPI_SELECT(priv->spi, priv->spidev, true);
SPI_SEND(priv->spi, (data >> 8));
SPI_SEND(priv->spi, (data & 0xff));
SPI_SELECT(priv->spi, priv->spidev, false);
SPI_LOCK(priv->spi, false);
dac_txdone(dev);
return 0;
}
/****************************************************************************
* Name: mcp48xx_ioctl
****************************************************************************/
static int mcp48xx_ioctl(FAR struct dac_dev_s *dev, int cmd,
unsigned long arg)
{
FAR struct mcp48xx_dev_s *priv = (FAR struct mcp48xx_dev_s *)dev->ad_priv;
int ret = OK;
switch (cmd)
{
case ANIOC_MCP48XX_DAC_SET_GAIN:
{
int i;
if ((arg & MCP48XX_GAIN_1X) != 0)
{
for (i = 0; i < MCP48XX_MAX_CHANNELS; i++)
{
if ((arg & (1u << i)) != 0)
{
priv->cmd[i] |= MCP48XX_GA;
}
}
}
else
{
for (i = 0; i < MCP48XX_MAX_CHANNELS; i++)
{
if ((arg & (1u << i)) != 0)
{
priv->cmd[i] &= ~MCP48XX_GA;
}
}
}
}
break;
case ANIOC_MCP48XX_DAC_ENABLE:
{
int i;
for (i = 0; i < MCP48XX_MAX_CHANNELS; i++)
{
if ((arg & (1u << i)) != 0)
{
priv->cmd[i] |= MCP48XX_SHDN;
}
}
}
break;
case ANIOC_MCP48XX_DAC_DISABLE:
{
int i;
for (i = 0; i < MCP48XX_MAX_CHANNELS; i++)
{
if ((arg & (1u << i)) != 0)
{
priv->cmd[i] &= ~MCP48XX_SHDN;
}
}
}
break;
/* Command was not recognized */
default:
aerr("MCP48XX ERROR: Unrecognized cmd: %d\n", cmd);
ret = -ENOTTY;
break;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: mcp48xx_initialize
*
* Description:
* Initialize DAC
*
* Input Parameters:
* spi - SPI driver instance
* spidev - SPI Chip Select number
*
* Returned Value:
* Valid MCP48XX device structure reference on success; a NULL on failure
*
****************************************************************************/
FAR struct dac_dev_s *mcp48xx_initialize(FAR struct spi_dev_s *spi,
uint32_t spidev)
{
FAR struct mcp48xx_dev_s *priv;
int i;
/* Sanity check */
DEBUGASSERT(spi != NULL);
/* Initialize the MCP48XX device structure */
priv = (FAR struct mcp48xx_dev_s *)g_dacdev.ad_priv;
priv->spi = spi;
priv->spidev = spidev;
/* Enable both channels with 1x gain by default */
for (i = 0; i < MCP48XX_MAX_CHANNELS; i++)
{
priv->cmd[i] = MCP48XX_SHDN | MCP48XX_GA;
}
return &g_dacdev;
}
#endif /* CONFIG_MCP48XX */
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