/**************************************************************************** * drivers/lcd/max7219.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. * ****************************************************************************/ /* Driver for the Maxim MAX7219 used for driver 8x8 LED display chains. */ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Configuration ************************************************************/ /* MAX7219 Configuration Settings: * * CONFIG_MAX7219_NHORIZONTALBLKS - Specifies the number of physical * MAX7219 devices that are connected together horizontally. * * CONFIG_MAX7219_NVERTICALBLKS - Specifies the number of physical * MAX7219 devices that are connected together vertically. * * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs. * * Required LCD driver settings: * CONFIG_LCD_MAX7219 - Enable MAX7219 support * */ /* Verify that all configuration requirements have been met */ /* SPI frequency */ #ifndef CONFIG_MAX7219_FREQUENCY # define CONFIG_MAX7219_FREQUENCY 10000000 #endif /* MAX7219_NHORIZONTALBLKS determines the number of physical 8x8 LEDs * matrices that are used connected horizontally. */ #ifndef CONFIG_MAX7219_NHORIZONTALBLKS # define CONFIG_MAX7219_NHORIZONTALBLKS 1 #endif /* MAX7219_NVERTICALBLKS determines the number of physical 8x8 LEDs * matrices that are used connected vertically. */ #ifndef CONFIG_MAX7219_NVERTICALBLKS # define CONFIG_MAX7219_NVERTICALBLKS 1 #endif #if CONFIG_LCD_MAXCONTRAST > 15 # undef CONFIG_LCD_MAXCONTRAST # define CONFIG_LCD_MAXCONTRAST 15 #endif /* Color Properties *********************************************************/ /* The MAX7219 chip can handle resolution of 8x8, 16x8, 8x16, 16x16, 24x8, * etc. */ /* Display Resolution */ #define MAX7219_XRES (8 * CONFIG_MAX7219_NHORIZONTALBLKS) #define MAX7219_YRES (8 * CONFIG_MAX7219_NVERTICALBLKS) /* Color depth and format */ #define MAX7219_BPP 1 #define MAX7219_COLORFMT FB_FMT_Y1 /* Bytes per logical row and actual device row */ #define MAX7219_XSTRIDE (MAX7219_XRES >> 3) /* Pixels arrange "horizontally for user" */ #define MAX7219_YSTRIDE (MAX7219_YRES >> 3) /* Pixels arrange "vertically for user" */ /* The size of the shadow frame buffer */ #define MAX7219_FBSIZE (MAX7219_XRES * MAX7219_YSTRIDE) + 1 /* Bit helpers */ #define LS_BIT (1 << 0) #define MS_BIT (1 << 7) #define BIT(nr) (1 << (nr)) #define BITS_PER_BYTE 8 #define BIT_MASK(nr) (1 << ((nr) % BITS_PER_BYTE)) #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE) /**************************************************************************** * Private Type Definition ****************************************************************************/ /* This structure describes the state of this driver */ struct max7219_dev_s { /* Publicly visible device structure */ struct lcd_dev_s dev; /* Private LCD-specific information follows */ FAR struct spi_dev_s *spi; uint8_t contrast; uint8_t powered; /* The MAX7219 does not support reading from the display memory in SPI * mode. Since there is 1 BPP and access is byte-by-byte, it is necessary * to keep a shadow copy of the framebuffer memory. */ uint8_t fb[MAX7219_FBSIZE]; }; /**************************************************************************** * Private Function Protototypes ****************************************************************************/ /* SPI helpers */ static void max7219_select(FAR struct spi_dev_s *spi); static void max7219_deselect(FAR struct spi_dev_s *spi); /* LCD Data Transfer Methods */ static int max7219_putrun(fb_coord_t row, fb_coord_t col, FAR const uint8_t *buffer, size_t npixels); static int max7219_getrun(fb_coord_t row, fb_coord_t col, FAR uint8_t *buffer, size_t npixels); /* LCD Configuration */ static int max7219_getvideoinfo(FAR struct lcd_dev_s *dev, FAR struct fb_videoinfo_s *vinfo); static int max7219_getplaneinfo(FAR struct lcd_dev_s *dev, unsigned int planeno, FAR struct lcd_planeinfo_s *pinfo); /* LCD RGB Mapping */ #ifdef CONFIG_FB_CMAP # error "RGB color mapping not supported by this driver" #endif /* Cursor Controls */ #ifdef CONFIG_FB_HWCURSOR # error "Cursor control not supported by this driver" #endif /* LCD Specific Controls */ static int max7219_getpower(FAR struct lcd_dev_s *dev); static int max7219_setpower(FAR struct lcd_dev_s *dev, int power); static int max7219_getcontrast(FAR struct lcd_dev_s *dev); static int max7219_setcontrast(FAR struct lcd_dev_s *dev, unsigned int contrast); /* Initialization */ static inline void up_clear(FAR struct max7219_dev_s *priv); /**************************************************************************** * Private Data ****************************************************************************/ /* This is working memory allocated by the LCD driver for each LCD device * and for each color plane. This memory will hold one raster line of data. * The size of the allocated run buffer must therefore be at least * (bpp * xres / 8). Actual alignment of the buffer must conform to the * bitwidth of the underlying pixel type. * * If there are multiple planes, they may share the same working buffer * because different planes will not be operate on concurrently. However, * if there are multiple LCD devices, they must each have unique run buffers. */ static uint8_t g_runbuffer[MAX7219_XSTRIDE + 1]; /* This structure describes the overall LCD video controller */ static const struct fb_videoinfo_s g_videoinfo = { MAX7219_COLORFMT, /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */ MAX7219_XRES, /* Horizontal resolution in pixel columns */ MAX7219_YRES, /* Vertical resolution in pixel rows */ 1, /* Number of color planes supported */ }; /* This is the standard, NuttX Plane information object */ static const struct lcd_planeinfo_s g_planeinfo = { .putrun = max7219_putrun, /* Put a run into LCD memory */ .getrun = max7219_getrun, /* Get a run from LCD memory */ .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */ .bpp = MAX7219_BPP, /* Bits-per-pixel */ }; /* This is the standard, NuttX LCD driver object */ static struct max7219_dev_s g_max7219dev = { /* struct lcd_dev_s */ { /* LCD Configuration */ max7219_getvideoinfo, max7219_getplaneinfo, #ifdef CONFIG_FB_CMAP /* LCD RGB Mapping -- Not supported */ NULL, NULL, #endif #ifdef CONFIG_FB_HWCURSOR /* Cursor Controls -- Not supported */ NULL, NULL, #endif /* LCD Specific Controls */ max7219_getpower, max7219_setpower, max7219_getcontrast, max7219_setcontrast, }, }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * __set_bit - Set a bit in memory * * nr - The bit to set * addr - The address to start counting from * * Unlike set_bit(), this function is non-atomic and may be reordered. * If it's called on the same region of memory simultaneously, the effect * may be that only one operation succeeds. * ****************************************************************************/ static inline void __set_bit(int nr, uint8_t * addr) { uint8_t mask = BIT_MASK(nr); uint8_t *p = ((uint8_t *) addr) + BIT_BYTE(nr); *p |= mask; } static inline void __clear_bit(int nr, uint8_t * addr) { uint8_t mask = BIT_MASK(nr); uint8_t *p = ((uint8_t *) addr) + BIT_BYTE(nr); *p &= ~mask; } static inline int __test_bit(int nr, const volatile uint8_t * addr) { return 1 & (addr[BIT_BYTE(nr)] >> (nr & (BITS_PER_BYTE - 1))); } /**************************************************************************** * Name: max7219_powerstring * * Description: * Convert the power setting to a string. * ****************************************************************************/ static inline FAR const char *max7219_powerstring(uint8_t power) { if (power == MAX7219_POWER_OFF) { return "OFF"; } else if (power == MAX7219_POWER_ON) { return "ON"; } else { return "ERROR"; } } /**************************************************************************** * Name: max7219_select * * Description: * Select the SPI, locking and re-configuring if necessary * * Input Parameters: * spi - Reference to the SPI driver structure * * Returned Value: * None * ****************************************************************************/ static void max7219_select(FAR struct spi_dev_s *spi) { /* Select MAX7219 chip (locking the SPI bus in case there are multiple * devices competing for the SPI bus */ SPI_LOCK(spi, true); SPI_SELECT(spi, SPIDEV_DISPLAY(0), true); /* Now make sure that the SPI bus is configured for the MAX7219 (it * might have gotten configured for a different device while unlocked) */ SPI_SETMODE(spi, SPIDEV_MODE0); SPI_SETBITS(spi, 8); SPI_HWFEATURES(spi, 0); SPI_SETFREQUENCY(spi, CONFIG_MAX7219_FREQUENCY); } /**************************************************************************** * Name: max7219_deselect * * Description: * De-select the SPI * * Input Parameters: * spi - Reference to the SPI driver structure * * Returned Value: * None * ****************************************************************************/ static void max7219_deselect(FAR struct spi_dev_s *spi) { /* De-select MAX7219 chip and relinquish the SPI bus. */ SPI_SELECT(spi, SPIDEV_DISPLAY(0), false); SPI_LOCK(spi, false); } /**************************************************************************** * Name: max7219_putrun * * Description: * This method can be used to write a partial raster line to the LCD: * * row - Starting row to write to (range: 0 <= row < yres) * col - Starting column to write to (range: 0 <= col <= xres-npixels) * buffer - The buffer containing the run to be written to the LCD * npixels - The number of pixels to write to the LCD * (range: 0 < npixels <= xres-col) * ****************************************************************************/ static int max7219_putrun(fb_coord_t row, fb_coord_t col, FAR const uint8_t *buffer, size_t npixels) { /* Because of this line of code, we will only be able to support a single * MAX7219 device . */ FAR struct max7219_dev_s *priv = &g_max7219dev; FAR uint8_t *fbptr; FAR uint8_t *ptr; uint16_t data; uint8_t usrmask; int i; int pixlen; int newrow; ginfo("row: %d col: %d npixels: %d\n", row, col, npixels); DEBUGASSERT(buffer); /* Clip the run to the display */ pixlen = npixels; if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)MAX7219_XRES) { pixlen = (int)MAX7219_XRES - (int)col; } /* Verify that some portion of the run remains on the display */ if (pixlen <= 0 || row > MAX7219_YRES) { return OK; } /* Get real row position in the strip */ newrow = (int) (row % 8); /* Divide row by 8 */ row = (row >> 3); col = col + (row * MAX7219_XRES); row = newrow; #ifdef CONFIG_LCD_PACKEDMSFIRST usrmask = MS_BIT; #else usrmask = LS_BIT; #endif #ifdef CONFIG_LCD_PACKEDMSFIRST usrmask = MS_BIT; #else usrmask = LS_BIT; #endif fbptr = &priv->fb[row * MAX7219_XSTRIDE * MAX7219_YSTRIDE]; ptr = fbptr + (col >> 3); for (i = 0; i < pixlen; i++) { if ((*buffer & usrmask) != 0) { __set_bit(col % 8 + i, ptr); } else { __clear_bit(col % 8 + i, ptr); } #ifdef CONFIG_LCD_PACKEDMSFIRST if (usrmask == LS_BIT) { buffer++; usrmask = MS_BIT; } else { usrmask >>= 1; } #else if (usrmask == MS_BIT) { buffer++; usrmask = LS_BIT; } else { usrmask <<= 1; } #endif } /* Lock and select the device */ max7219_select(priv->spi); /* We need to send last row/column first to avoid mirror image */ for (i = (MAX7219_XSTRIDE * MAX7219_YSTRIDE) - 1; i >= 0; i--) { /* Setup the row data */ data = (8 - row) | (*(fbptr + i) << 8); /* Then transfer all 8 columns of data */ SPI_SNDBLOCK(priv->spi, &data, 2); } /* Unlock */ max7219_deselect(priv->spi); return OK; } /**************************************************************************** * Name: max7219_getrun * * Description: * This method can be used to read a partial raster line from the LCD: * * row - Starting row to read from (range: 0 <= row < yres) * col - Starting column to read read (range: 0 <= col <= xres-npixels) * buffer - The buffer in which to return the run read from the LCD * npixels - The number of pixels to read from the LCD * (range: 0 < npixels <= xres-col) * ****************************************************************************/ static int max7219_getrun(fb_coord_t row, fb_coord_t col, FAR uint8_t *buffer, size_t npixels) { /* Because of this line of code, we will only be able to support a single * MAX7219 device. */ FAR struct max7219_dev_s *priv = &g_max7219dev; FAR uint8_t *fbptr; FAR uint8_t *ptr; uint8_t usrmask; int i; int pixlen; ginfo("row: %d col: %d npixels: %d\n", row, col, npixels); DEBUGASSERT(buffer); /* Clip the run to the display */ pixlen = npixels; if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)MAX7219_XRES) { pixlen = (int)MAX7219_XRES - (int)col; } /* Verify that some portion of the run is actually the display */ if (pixlen <= 0 || row > MAX7219_YRES) { return -EINVAL; } #ifdef CONFIG_LCD_PACKEDMSFIRST usrmask = MS_BIT; #else usrmask = LS_BIT; #endif fbptr = &priv->fb[row * MAX7219_XSTRIDE]; ptr = fbptr + (col >> 3); for (i = 0; i < pixlen; i++) { if (__test_bit(col % 8 + i, ptr)) { *buffer |= usrmask; } else { *buffer &= ~usrmask; } #ifdef CONFIG_LCD_PACKEDMSFIRST if (usrmask == LS_BIT) { buffer++; usrmask = MS_BIT; } else { usrmask >>= 1; } #else if (usrmask == MS_BIT) { buffer++; usrmask = LS_BIT; } else { usrmask <<= 1; } #endif } return OK; } /**************************************************************************** * Name: max7219_getvideoinfo * * Description: * Get information about the LCD video controller configuration. * ****************************************************************************/ static int max7219_getvideoinfo(FAR struct lcd_dev_s *dev, FAR struct fb_videoinfo_s *vinfo) { DEBUGASSERT(dev && vinfo); ginfo("fmt: %d xres: %d yres: %d nplanes: %d\n", g_videoinfo.fmt, g_videoinfo.xres, g_videoinfo.yres, g_videoinfo.nplanes); memcpy(vinfo, &g_videoinfo, sizeof(struct fb_videoinfo_s)); return OK; } /**************************************************************************** * Name: max7219_getplaneinfo * * Description: * Get information about the configuration of each LCD color plane. * ****************************************************************************/ static int max7219_getplaneinfo(FAR struct lcd_dev_s *dev, unsigned int planeno, FAR struct lcd_planeinfo_s *pinfo) { DEBUGASSERT(dev && pinfo && planeno == 0); ginfo("planeno: %d bpp: %d\n", planeno, g_planeinfo.bpp); memcpy(pinfo, &g_planeinfo, sizeof(struct lcd_planeinfo_s)); return OK; } /**************************************************************************** * Name: max7219_getpower * * Description: * Get the LCD panel power status (0: full off - CONFIG_LCD_MAXPOWER: full * on). On backlit LCDs, this setting may correspond to the backlight * setting. * ****************************************************************************/ static int max7219_getpower(struct lcd_dev_s *dev) { struct max7219_dev_s *priv = (struct max7219_dev_s *)dev; DEBUGASSERT(priv); ginfo("powered: %s\n", max7219_powerstring(priv->powered)); return priv->powered; } /**************************************************************************** * Name: max7219_setpower * * Description: * Enable/disable LCD panel power (0: full off - CONFIG_LCD_MAXPOWER: full * on). On backlit LCDs, this setting may correspond to the backlight * setting. * ****************************************************************************/ static int max7219_setpower(struct lcd_dev_s *dev, int power) { struct max7219_dev_s *priv = (struct max7219_dev_s *)dev; uint16_t data; DEBUGASSERT(priv && (unsigned)power <= CONFIG_LCD_MAXPOWER); ginfo("power: %s powered: %s\n", max7219_powerstring(power), max7219_powerstring(priv->powered)); /* Select and lock the device */ max7219_select(priv->spi); if (power <= MAX7219_POWER_OFF) { data = (MAX7219_SHUTDOWN) | (MAX7219_POWER_OFF << 8); /* Turn the display off (power-down) */ SPI_SNDBLOCK(priv->spi, &data, 2); priv->powered = MAX7219_POWER_OFF; } else { data = (MAX7219_SHUTDOWN) | (MAX7219_POWER_ON << 8); /* Leave the power-down */ SPI_SNDBLOCK(priv->spi, &data, 2); priv->powered = MAX7219_POWER_ON; } /* Let go of the SPI lock and de-select the device */ max7219_deselect(priv->spi); return OK; } /**************************************************************************** * Name: max7219_getcontrast * * Description: * Get the current contrast setting (0-CONFIG_LCD_MAXCONTRAST). * ****************************************************************************/ static int max7219_getcontrast(struct lcd_dev_s *dev) { struct max7219_dev_s *priv = (struct max7219_dev_s *)dev; DEBUGASSERT(priv); return (int)priv->contrast; } /**************************************************************************** * Name: max7219_setcontrast * * Description: * Set LCD panel contrast (0-CONFIG_LCD_MAXCONTRAST). * ****************************************************************************/ static int max7219_setcontrast(struct lcd_dev_s *dev, unsigned int contrast) { struct max7219_dev_s *priv = (struct max7219_dev_s *)dev; uint16_t data; ginfo("contrast: %d\n", contrast); DEBUGASSERT(priv); if (contrast > 15) { return -EINVAL; } /* Save the contrast */ priv->contrast = contrast; /* Select and lock the device */ max7219_select(priv->spi); /* Configure the contrast/intensity */ data = (MAX7219_INTENSITY) | (DISPLAY_INTENSITY(contrast) << 8); /* Set the contrast */ SPI_SNDBLOCK(priv->spi, &data, 2); /* Let go of the SPI lock and de-select the device */ max7219_deselect(priv->spi); return OK; } /**************************************************************************** * Name: up_clear * * Description: * Clear the display. * ****************************************************************************/ static inline void up_clear(FAR struct max7219_dev_s *priv) { FAR struct spi_dev_s *spi = priv->spi; uint16_t data; int row; int i; /* Clear the framebuffer */ memset(priv->fb, MAX7219_BLACK, MAX7219_FBSIZE); /* Go throw max7219 all 8 rows */ for (row = 0, i = 0; i < 8; i++) { /* Select and lock the device */ max7219_select(priv->spi); /* Setup the row data */ data = (row + 1) | (priv->fb[row] << 8); /* Then transfer all 8 columns of data */ SPI_SNDBLOCK(priv->spi, &data, 2); /* Unlock and de-select the device */ max7219_deselect(spi); } } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: max7219_initialize * * Description: * Initialize the MAX7219 device as a LCD interface. * * Input Parameters: * spi - An instance of the SPI interface to use to communicate * with the MAX7219. * devno - Device number to identify current display. * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ FAR struct lcd_dev_s *max7219_initialize(FAR struct spi_dev_s *spi, unsigned int devno) { /* Configure and enable LCD */ FAR struct max7219_dev_s *priv = &g_max7219dev; uint16_t data; ginfo("Initializing\n"); DEBUGASSERT(spi && devno == 0); /* Save the reference to the SPI device */ priv->spi = spi; /* Select and lock the device */ max7219_select(spi); /* Leave the shutdown mode */ data = (MAX7219_SHUTDOWN) | (MAX7219_POWER_ON << 8); SPI_SNDBLOCK(priv->spi, &data, 2); max7219_deselect(spi); max7219_select(spi); /* Disable 7 segment decoding */ data = (MAX7219_DECODE_MODE) | (DISABLE_DECODE << 8); SPI_SNDBLOCK(priv->spi, &data, 2); max7219_deselect(spi); max7219_select(spi); /* Set scan limit for all digits */ data = (MAX7219_SCAN_LIMIT) | (DEFAULT_SCAN_LIMIT << 8); SPI_SNDBLOCK(priv->spi, &data, 2); max7219_deselect(spi); max7219_select(spi); /* Set intensity level configured by the user */ data = (MAX7219_INTENSITY) | (DISPLAY_INTENSITY(CONFIG_LCD_MAXCONTRAST) << 8); SPI_SNDBLOCK(priv->spi, &data, 2); /* Let go of the SPI lock and de-select the device */ max7219_deselect(spi); /* Clear the framebuffer */ up_clear(priv); return &priv->dev; }