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drivers/leds/max7219.c: Support all digits presented in the MAX7219 datasheet.

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This commit is contained in:
Alan Carvalho de Assis 2018-09-29 11:16:45 -06:00 committed by Gregory Nutt
parent d8bfb4e3a2
commit c4a906aef4
1 changed files with 105 additions and 20 deletions
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125
drivers/leds/max7219.c
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@ -161,7 +161,7 @@ static inline void max7219_write16(FAR struct max7219_dev_s *priv,
(void)SPI_SNDBLOCK(priv->spi, &value, 2);
/* Deselect */
/* De-select */
SPI_SELECT(priv->spi, SPIDEV_DISPLAY(0), false);
@ -214,37 +214,108 @@ static ssize_t max7219_write(FAR struct file *filep, FAR const char *buffer,
{
FAR struct inode *inode = filep->f_inode;
FAR struct max7219_dev_s *priv = inode->i_private;
FAR const char *leds = (FAR char *) buffer;
uint16_t data;
uint8_t digits[8];
uint8_t digcnt = 0;
uint8_t i;
if (!leds)
if (buffer == NULL)
{
snerr("ERROR: Buffer is null\n");
lederr("ERROR: Buffer is null\n");
return -1;
}
/* At least one display, so 1 byte */
/* We need at least one display, so 1 byte */
if (buflen < 1)
{
snerr("ERROR: You need to control at least 1 digit!\n");
lederr("ERROR: You need to control at least 1 digit!\n");
return -1;
}
/* It can control up to 8 digits (8 7-segment displays) */
/* Get and count the valid digits */
if (buflen > 8)
for (i = 0; i < buflen; i++)
{
snerr("ERROR: The limit is 8 digits!\n");
return -1;
if (buffer[i] >= '0' && buffer[i] <= '9')
{
digits[digcnt] = buffer[i] - '0';
digcnt++;
}
else
{
switch (buffer[i])
{
case '-':
digits[digcnt] = 0x0a;
digcnt++;
break;
case 'E':
digits[digcnt] = 0x0b;
digcnt++;
break;
case 'H':
digits[digcnt] = 0x0c;
digcnt++;
break;
case 'L':
digits[digcnt] = 0x0d;
digcnt++;
break;
case 'P':
digits[digcnt] = 0x0e;
digcnt++;
break;
case ' ':
digits[digcnt] = 0x0f;
digcnt++;
break;
case '.':
if (i == 0)
{
digits[0] = 0x0f | 0x80;
digcnt++;
}
else
{
digits[digcnt - 1] |= 0x80;
}
break;
default:
lederr("Digit code unsupported\n");
break;
}
}
/* If we reach 8 digits then stop */
if (digcnt >= 8 && buffer[i + 1] != '.')
{
ledwarn("ERROR: The limit is 8 digits!\n");
break;
}
}
/* Blank the display */
for (i = 0; i < 8; i++)
{
data = (MAX7219_DIGIT0 + i) | (0x0f << 8);
max7219_write16(priv, data);
}
/* Write each digit */
for (i = 0; i < buflen; i++)
for (i = 0; i < digcnt; i++)
{
data = (MAX7219_DIGIT0 + i) | (leds[i] - '0') << 8;
data = (MAX7219_DIGIT0 + i) | (digits[digcnt - i - 1]) << 8;
max7219_write16(priv, data);
}
@ -258,7 +329,7 @@ static ssize_t max7219_write(FAR struct file *filep, FAR const char *buffer,
****************************************************************************/
/****************************************************************************
* Name: max7219_register
* Name: max7219_leds_register
*
* Description:
* Register the MAX7219 character device as 'devpath'
@ -281,23 +352,19 @@ int max7219_leds_register(FAR const char *devpath, FAR struct spi_dev_s *spi)
FAR struct max7219_dev_s *priv;
uint16_t data;
int ret;
int i;
/* Initialize the MAX7219 device structure */
priv = (FAR struct max7219_dev_s *)kmm_malloc(sizeof(struct max7219_dev_s));
if (!priv)
{
snerr("ERROR: Failed to allocate instance\n");
lederr("ERROR: Failed to allocate instance\n");
return -ENOMEM;
}
priv->spi = spi;
/* Leave the shutdown mode */
data = (MAX7219_SHUTDOWN) | (MAX7219_POWER_ON << 8);
max7219_write16(priv, data);
/* Setup defined intensity */
data = (MAX7219_INTENSITY) |
@ -309,12 +376,30 @@ int max7219_leds_register(FAR const char *devpath, FAR struct spi_dev_s *spi)
data = (MAX7219_DECODE_MODE) | (ENABLE_DECODE << 8);
max7219_write16(priv, data);
/* Display all digits */
data = (MAX7219_SCAN_LIMIT) | (0x07 << 8);
max7219_write16(priv, data);
/* Leave the shutdown mode */
data = (MAX7219_SHUTDOWN) | (MAX7219_POWER_ON << 8);
max7219_write16(priv, data);
/* Blank the display */
for (i = 0; i < 8; i++)
{
data = (MAX7219_DIGIT0 + i) | (0x0f << 8);
max7219_write16(priv, data);
}
/* Register the character driver */
ret = register_driver(devpath, &g_max7219fops, 0666, priv);
if (ret < 0)
{
snerr("ERROR: Failed to register driver: %d\n", ret);
lederr("ERROR: Failed to register driver: %d\n", ret);
kmm_free(priv);
}