394 lines
10 KiB
C
394 lines
10 KiB
C
/****************************************************************************
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* drivers/leds/max7219.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/* Maxim MAX7219 driver used to control 7-segment display. */
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <stdlib.h>
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#include <errno.h>
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#include <debug.h>
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#include <nuttx/kmalloc.h>
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#include <nuttx/fs/fs.h>
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#include <nuttx/spi/spi.h>
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#include <nuttx/leds/max7219.h>
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#if defined(CONFIG_SPI) && defined(CONFIG_LEDS_MAX7219)
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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/* SPI frequency */
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#ifndef CONFIG_MAX7219_FREQUENCY
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# define CONFIG_MAX7219_FREQUENCY 5000000
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#endif
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#ifndef CONFIG_MAX7219_INTENSITY
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# define CONFIG_MAX7219_INTENSITY 8
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#endif
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/****************************************************************************
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* Private Types
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****************************************************************************/
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struct max7219_dev_s
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{
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FAR struct spi_dev_s *spi; /* SPI interface */
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};
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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static inline void max7219_configspi(FAR struct spi_dev_s *spi);
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static inline void max7219_write16(FAR struct max7219_dev_s *priv,
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uint16_t value);
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/* Character driver methods */
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static int max7219_open(FAR struct file *filep);
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static int max7219_close(FAR struct file *filep);
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static ssize_t max7219_read(FAR struct file *filep, FAR char *buffer,
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size_t buflen);
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static ssize_t max7219_write(FAR struct file *filep, FAR const char *buffer,
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size_t buflen);
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/****************************************************************************
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* Private Data
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****************************************************************************/
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static const struct file_operations g_max7219fops =
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{
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max7219_open, /* open */
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max7219_close, /* close */
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max7219_read, /* read */
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max7219_write, /* write */
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NULL, /* seek */
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NULL, /* ioctl */
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NULL /* poll */
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#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
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, NULL /* unlink */
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#endif
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};
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: max7219_configspi
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*
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* Description:
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* Set the SPI bus configuration
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*
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****************************************************************************/
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static inline void max7219_configspi(FAR struct spi_dev_s *spi)
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{
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/* Configure SPI for the MAX7219 */
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SPI_SETMODE(spi, SPIDEV_MODE0);
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SPI_SETBITS(spi, 8);
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SPI_HWFEATURES(spi, 0);
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SPI_SETFREQUENCY(spi, CONFIG_MAX7219_FREQUENCY);
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}
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/****************************************************************************
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* Name: max7219_write16
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*
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* Description:
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* Write 16-bit to MAX7219
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*
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****************************************************************************/
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static inline void max7219_write16(FAR struct max7219_dev_s *priv,
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uint16_t value)
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{
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/* If SPI bus is shared then lock and configure it */
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SPI_LOCK(priv->spi, true);
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/* Configure the SPI */
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max7219_configspi(priv->spi);
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/* Select */
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SPI_SELECT(priv->spi, SPIDEV_DISPLAY(0), true);
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/* Send 16 bits (2 bytes) */
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SPI_SNDBLOCK(priv->spi, &value, 2);
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/* De-select */
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SPI_SELECT(priv->spi, SPIDEV_DISPLAY(0), false);
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/* Unlock bus */
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SPI_LOCK(priv->spi, false);
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}
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/****************************************************************************
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* Name: max7219_open
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*
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* Description:
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* This function is called whenever the MAX7219 device is opened.
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*
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****************************************************************************/
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static int max7219_open(FAR struct file *filep)
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{
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return OK;
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}
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/****************************************************************************
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* Name: max7219_close
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*
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* Description:
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* This routine is called when the LM-75 device is closed.
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*
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****************************************************************************/
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static int max7219_close(FAR struct file *filep)
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{
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return OK;
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}
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/****************************************************************************
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* Name: max7219_read
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****************************************************************************/
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static ssize_t max7219_read(FAR struct file *filep,
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FAR char *buffer, size_t buflen)
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{
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return -ENOSYS;
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}
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/****************************************************************************
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* Name: max7219_write
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****************************************************************************/
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static ssize_t max7219_write(FAR struct file *filep, FAR const char *buffer,
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size_t buflen)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct max7219_dev_s *priv = inode->i_private;
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uint16_t data;
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uint8_t digits[8];
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uint8_t digcnt = 0;
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uint8_t i;
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if (buffer == NULL)
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{
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lederr("ERROR: Buffer is null\n");
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return -1;
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}
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/* We need at least one display, so 1 byte */
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if (buflen < 1)
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{
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lederr("ERROR: You need to control at least 1 digit!\n");
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return -1;
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}
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/* Get and count the valid digits */
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for (i = 0; i < buflen; i++)
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{
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if (buffer[i] >= '0' && buffer[i] <= '9')
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{
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digits[digcnt] = buffer[i] - '0';
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digcnt++;
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}
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else
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{
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switch (buffer[i])
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{
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case '-':
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digits[digcnt] = 0x0a;
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digcnt++;
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break;
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case 'E':
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digits[digcnt] = 0x0b;
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digcnt++;
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break;
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case 'H':
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digits[digcnt] = 0x0c;
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digcnt++;
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break;
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case 'L':
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digits[digcnt] = 0x0d;
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digcnt++;
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break;
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case 'P':
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digits[digcnt] = 0x0e;
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digcnt++;
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break;
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case ' ':
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digits[digcnt] = 0x0f;
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digcnt++;
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break;
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case '.':
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if (i == 0)
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{
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digits[0] = 0x0f | 0x80;
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digcnt++;
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}
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else
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{
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digits[digcnt - 1] |= 0x80;
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}
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break;
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default:
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lederr("Digit code unsupported\n");
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break;
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}
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}
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/* If we reach 8 digits then stop */
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if (digcnt >= 8 && buffer[i + 1] != '.')
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{
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ledwarn("ERROR: The limit is 8 digits!\n");
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break;
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}
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}
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/* Blank the display */
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for (i = 0; i < 8; i++)
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{
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data = (MAX7219_DIGIT0 + i) | (0x0f << 8);
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max7219_write16(priv, data);
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}
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/* Write each digit */
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for (i = 0; i < digcnt; i++)
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{
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data = (MAX7219_DIGIT0 + i) | (digits[digcnt - i - 1]) << 8;
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max7219_write16(priv, data);
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}
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/* All bytes were written */
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return buflen;
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: max7219_leds_register
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*
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* Description:
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* Register the MAX7219 character device as 'devpath'
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*
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* Input Parameters:
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* devpath - The full path to the driver to register. E.g., "/dev/temp0"
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* i2c - An instance of the I2C interface to use to communicate with
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* MAX7219
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* addr - The I2C address of the LM-75. The base I2C address of the
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* MAX7219 is 0x48. Bits 0-3 can be controlled to get 8 unique
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* addresses from 0x48 through 0x4f.
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*
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* Returned Value:
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* Zero (OK) on success; a negated errno value on failure.
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*
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****************************************************************************/
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int max7219_leds_register(FAR const char *devpath, FAR struct spi_dev_s *spi)
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{
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FAR struct max7219_dev_s *priv;
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uint16_t data;
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int ret;
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int i;
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/* Initialize the MAX7219 device structure */
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priv = (FAR struct max7219_dev_s *)
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kmm_malloc(sizeof(struct max7219_dev_s));
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if (!priv)
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{
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lederr("ERROR: Failed to allocate instance\n");
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return -ENOMEM;
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}
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priv->spi = spi;
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/* Setup defined intensity */
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data = (MAX7219_INTENSITY) |
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(DISPLAY_INTENSITY(CONFIG_MAX7219_INTENSITY) << 8);
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max7219_write16(priv, data);
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/* Enable decoding for all digits */
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data = (MAX7219_DECODE_MODE) | (ENABLE_DECODE << 8);
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max7219_write16(priv, data);
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/* Display all digits */
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data = (MAX7219_SCAN_LIMIT) | (0x07 << 8);
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max7219_write16(priv, data);
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/* Leave the shutdown mode */
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data = (MAX7219_SHUTDOWN) | (MAX7219_POWER_ON << 8);
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max7219_write16(priv, data);
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/* Blank the display */
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for (i = 0; i < 8; i++)
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{
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data = (MAX7219_DIGIT0 + i) | (0x0f << 8);
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max7219_write16(priv, data);
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}
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/* Register the character driver */
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ret = register_driver(devpath, &g_max7219fops, 0666, priv);
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if (ret < 0)
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{
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lederr("ERROR: Failed to register driver: %d\n", ret);
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kmm_free(priv);
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}
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return ret;
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}
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#endif /* CONFIG_SPI && CONFIG_MAX7219 */
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