/**************************************************************************** * drivers/lcd/ht16k33_14seg.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. * ****************************************************************************/ /* Alphanumeric display driver for HOLTEK HT16K33 (and VINKA VK16K33 clone) * This driver is specific for a 0.54" 14-segment LED HT16K33 Backpack * module with 4 14-segment digits (2 Kingbright 5241AS display). * Note: the model I'm testing uses the VK16K33. * * This is how the displays are connected: * Left Display: Digit 1: Catode connected to COM3 * Left Display: Digit 2: Catode connected to COM2 * Right Display: Digit 1: Catode connected to COM1 * Right Display: Digit 2: Catode connected to COM0 * * 14-Segment | LED Controller * ------------------------------- * 8 - DP | ROW14 - 11 * 13 - p | ROW6 - 19 * 2 - n | ROW11 - 14 * 4 - m | ROW12 - 13 * 5 - l | ROW13 - 12 * 6 - k | ROW7 - 18 * 14 - j | ROW10 - 15 * 15 - h | ROW9 - 16 * 17 - g | ROW8 - 17 * 18 - f | ROW5 - 20 * 1 - e | ROW4 - 21 * 7 - d | ROW3 - 22 * 9 - c | ROW2 - 23 * 10 - b | ROW1 - 24 * 12 - a | ROW0 - 25 */ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef CONFIG_LIBC_SLCDCODEC # error please also select Library Routines, Segment LCD CODEC #endif #if defined(CONFIG_I2C) && defined(CONFIG_LCD_HT16K33) /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* I2C frequency */ #ifndef CONFIG_HT16K33_I2C_FREQ # define CONFIG_HT16K33_I2C_FREQ 400000 #endif #ifndef CONFIG_LCD_HT16K33_NUMBER_MODULES # define CONFIG_LCD_HT16K33_NUMBER_MODULES 1 #endif #define HT16K33_MAX_ROW 1 #define HT16K33_MAX_COL 4 * CONFIG_LCD_HT16K33_NUMBER_MODULES /* Device naming ************************************************************/ #define DEVNAME_FMT "/dev/slcd%d" #define DEVNAME_FMTLEN (9 + 3 + 1) /**************************************************************************** * Private Types ****************************************************************************/ struct ht16k33_dev_s { FAR struct i2c_master_s *i2c; /* I2C interface */ uint8_t row; /* Current row position to write on display */ uint8_t col; /* Current col position to write on display */ uint8_t buffer[HT16K33_MAX_COL]; bool pendscroll; sem_t sem_excl; }; struct lcd_instream_s { struct lib_instream_s stream; FAR const char *buffer; ssize_t nbytes; }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ static inline void ht16k33_write_cmd(FAR struct ht16k33_dev_s *priv, int dev_id, uint8_t cmd); static inline void ht16k33_write_data(FAR struct ht16k33_dev_s *priv, int dev_id, uint8_t cmd, uint8_t *values, int nbytes); static inline void ht16k33_setcontrast(FAR struct ht16k33_dev_s *priv, int dev_id, int8_t contrast); static void lcd_scroll_up(FAR struct ht16k33_dev_s *priv); static void ht16k33_clear_display(FAR struct ht16k33_dev_s *priv); /* Character driver methods */ static int ht16k33_open(FAR struct file *filep); static int ht16k33_close(FAR struct file *filep); static ssize_t ht16k33_read(FAR struct file *filep, FAR char *buffer, size_t buflen); static ssize_t ht16k33_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); static off_t ht16k33_seek(FAR struct file *filep, off_t offset, int whence); static int ht16k33_ioctl(FAR struct file *filep, int cmd, unsigned long arg); /**************************************************************************** * Private Data ****************************************************************************/ static const struct file_operations g_ht16k33fops = { ht16k33_open, /* open */ ht16k33_close, /* close */ ht16k33_read, /* read */ ht16k33_write, /* write */ ht16k33_seek, /* seek */ ht16k33_ioctl, /* ioctl */ NULL, /* poll */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS NULL /* unlink */ #endif }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: ht16k33_write_cmd * * Description: * Write an Instruction command to HT16K33 * ****************************************************************************/ static inline void ht16k33_write_cmd(FAR struct ht16k33_dev_s *priv, int dev_id, uint8_t cmd) { struct i2c_msg_s msg; uint8_t data[1]; int ret; /* Prepare data to send */ data[0] = cmd; /* Setup the HT16K33 Command */ msg.frequency = CONFIG_HT16K33_I2C_FREQ; /* I2C frequency */ msg.addr = HT16K33_I2C_ADDR + dev_id; /* 7-bit address */ msg.flags = 0; /* Write transaction */ msg.buffer = (FAR uint8_t *) data; /* Transfer from this address */ msg.length = 1; /* Send one byte */ /* Perform the transfer */ ret = I2C_TRANSFER(priv->i2c, &msg, 1); if (ret < 0) { lcderr("ERROR: I2C_TRANSFER failed: %d\n", ret); } } /**************************************************************************** * Name: ht16k33_write_data * * Description: * Write a Data command to HT16K33 * ****************************************************************************/ static inline void ht16k33_write_data(FAR struct ht16k33_dev_s *priv, int dev_id, uint8_t cmd, uint8_t *values, int nbytes) { struct i2c_msg_s msg; uint8_t data[16]; int ret; int i; /* Prepare data to send */ data[0] = cmd; for (i = 0; i < nbytes; i++) { data[i + 1] = values[i]; } /* Setup the message to write data to HT16K33 */ msg.frequency = CONFIG_HT16K33_I2C_FREQ; /* I2C frequency */ msg.addr = HT16K33_I2C_ADDR + dev_id; /* 7-bit address */ msg.flags = 0; /* Write transaction */ msg.buffer = (FAR uint8_t *) data; /* Transfer from here */ msg.length = nbytes + 1; /* Send cmd + nbytes */ /* Perform the transfer */ ret = I2C_TRANSFER(priv->i2c, &msg, 1); if (ret < 0) { lcderr("ERROR: I2C_TRANSFER failed: %d\n", ret); } } static inline void ht16k33_setcontrast(FAR struct ht16k33_dev_s *priv, int dev_id, int8_t contrast) { int i; if (contrast < HT16K33_CONTRAST_MIN) { contrast = HT16K33_CONTRAST_MIN; } else if (contrast > HT16K33_CONTRAST_MAX) { contrast = HT16K33_CONTRAST_MAX; } for (i = 0; i < CONFIG_LCD_HT16K33_NUMBER_MODULES; i++) { ht16k33_write_cmd(priv, i, HT16K33_DIMMING_SET | (contrast & 0x0f)); } } /**************************************************************************** * Name: lcd_getdata * * Description: * Simulate reading data from LCD, we are reading from internal buffer * ****************************************************************************/ static inline uint8_t lcd_getdata(FAR struct ht16k33_dev_s *priv) { uint8_t data; data = priv->buffer[priv->row * priv->col]; return data; } /**************************************************************************** * Name: rc2addr * * Description: * This converts a row/column pair to a screen memory address. * ****************************************************************************/ static inline uint8_t rc2addr(FAR struct ht16k33_dev_s *priv) { /* Each module has 4 digits they correspond to these columns: * * col0: 0x00 - 0x01, col1: 0x02 - 0x03, * col2: 0x04 - 0x05, col3: 0x06 - 0x07 */ return (priv->col % 4) * 0x02; } /**************************************************************************** * Name: addr2rc * * Description: * This converts a screen memory address to a row/column pair. * ****************************************************************************/ static inline void addr2rc(FAR struct ht16k33_dev_s *priv, uint8_t addr, FAR uint8_t *row, FAR uint8_t *col) { *row = 0; *col = addr / 2; } /**************************************************************************** * Name: lcd_set_curpos * * Description: * This sets the cursor position based on row, column addressing. * * Input Parameters: * priv - device instance * ****************************************************************************/ static void lcd_set_curpos(FAR struct ht16k33_dev_s *priv) { uint8_t addr; int dev_id; addr = rc2addr(priv); dev_id = priv->col / 4; /* Define the memory address position */ ht16k33_write_cmd(priv, dev_id, HT16K33_DISP_DATA_ADDR | addr); } /**************************************************************************** * Name: lcd_putdata * * Description: * Write a byte to the LCD and update column/row position * ****************************************************************************/ static inline void lcd_putdata(FAR struct ht16k33_dev_s *priv, uint8_t data) { uint8_t segment[2]; uint8_t addr; uint8_t cmd; int dev_id; /* Get current display memory position */ addr = rc2addr(priv); /* Setup the memory command */ cmd = HT16K33_DISP_DATA_ADDR | addr; /* Get the segments setting */ segment[0] = asciito14seg[data - 32] & 0xff; segment[1] = (asciito14seg[data - 32] & 0xff00) >> 8; dev_id = priv->col / 4; /* Send data to display */ ht16k33_write_data(priv, dev_id, cmd, segment, 2); /* Save it in the buffer because we cannot read from display */ priv->buffer[priv->col * priv->row] = data; /* Update col/row positions */ priv->col++; if (priv->col >= HT16K33_MAX_COL) { priv->col = 0; priv->row++; } if (priv->row >= HT16K33_MAX_ROW) { priv->pendscroll = true; priv->row = HT16K33_MAX_ROW - 1; } /* Update cursor position */ lcd_set_curpos(priv); } /**************************************************************************** * Name: lcd_scroll_up * * Description: * Scroll the display up, and clear the new (last) line. * ****************************************************************************/ static void lcd_scroll_up(FAR struct ht16k33_dev_s *priv) { FAR uint8_t *data; int currow; int curcol; data = (FAR uint8_t *)kmm_malloc(HT16K33_MAX_COL); if (NULL == data) { lcdinfo("Failed to allocate buffer in lcd_scroll_up()\n"); return; } for (currow = 1; currow < HT16K33_MAX_ROW; ++currow) { priv->row = currow; for (curcol = 0; curcol < HT16K33_MAX_COL; ++curcol) { priv->col = curcol; data[curcol] = lcd_getdata(priv); } priv->col = 0; priv->row = currow - 1; lcd_set_curpos(priv); for (curcol = 0; curcol < HT16K33_MAX_COL; ++curcol) { lcd_putdata(priv, data[curcol]); } } ht16k33_clear_display(priv); kmm_free(data); return; } /**************************************************************************** * Name: ht16k33_clear_display * * Description: * Clear the display writing space (' ') to all positions * ****************************************************************************/ static void ht16k33_clear_display(FAR struct ht16k33_dev_s *priv) { int curcol; priv->col = 0; priv->row = HT16K33_MAX_ROW - 1; lcd_set_curpos(priv); for (curcol = 0; curcol < HT16K33_MAX_COL; ++curcol) { lcd_putdata(priv, ' '); } priv->col = 0; priv->row = HT16K33_MAX_ROW - 1; lcd_set_curpos(priv); } /**************************************************************************** * Name: lcd_codec_action * * Description: * Perform an 'action' as per the Segment LCD codec. * * Input Parameters: * priv - device instance * code - SLCD code action code * count - count param for those actions that take it * ****************************************************************************/ static void lcd_codec_action(FAR struct ht16k33_dev_s *priv, enum slcdcode_e code, uint8_t count) { switch (code) { /* Erasure */ case SLCDCODE_BACKDEL: /* Backspace (backward delete) * N characters */ { if (count <= 0) /* we need to delete more 0 positions */ { break; } else { if (count > priv->col) /* saturate to preceding columns * available */ { count = priv->col; } priv->col = priv->col - count; lcd_set_curpos(priv); } /* ... and conscientiously fall through to next case ... */ } case SLCDCODE_FWDDEL: /* Delete (forward delete) N characters * moving text */ { if (count <= 0) /* we need to delete more 0 positions */ { break; } else { uint8_t start; uint8_t end; uint8_t i; uint8_t data; start = priv->col + count; if (start >= HT16K33_MAX_COL) /* nothing left */ { break; } end = start + count; if (end > HT16K33_MAX_COL) /* saturate */ { end = HT16K33_MAX_COL; } for (i = priv->col; i < end; ++start, ++i) /* like memmove */ { priv->col = start; lcd_set_curpos(priv); data = lcd_getdata(priv); priv->col = i; lcd_set_curpos(priv); lcd_putdata(priv, data); } for (; i < HT16K33_MAX_COL; ++i) /* much like memset */ { lcd_putdata(priv, ' '); } lcd_set_curpos(priv); } } break; case SLCDCODE_ERASE: /* Erase N characters from the cursor * position */ if (count > 0) { uint8_t end; uint8_t i; end = priv->col + count; if (end > HT16K33_MAX_COL) { end = HT16K33_MAX_COL; } for (i = priv->col; i < end; ++i) { lcd_putdata(priv, ' '); } lcd_set_curpos(priv); } break; case SLCDCODE_CLEAR: /* Home the cursor and erase the entire * display */ { /* ht16k33_write_cmd(priv, HT16K33_CLEAR_DISPLAY); */ } break; case SLCDCODE_ERASEEOL: /* Erase from the cursor position to * the end of line */ { uint8_t i; for (i = priv->col; i < HT16K33_MAX_COL; ++i) { lcd_putdata(priv, ' '); } lcd_set_curpos(priv); } break; /* Cursor movement */ case SLCDCODE_LEFT: /* Cursor left by N characters */ { if (count > priv->col) { priv->col = 0; } else { priv->col -= count; } lcd_set_curpos(priv); } break; case SLCDCODE_RIGHT: /* Cursor right by N characters */ { priv->col += count; if (priv->col >= HT16K33_MAX_COL) { priv->col = HT16K33_MAX_COL - 1; } lcd_set_curpos(priv); } break; case SLCDCODE_UP: /* Cursor up by N lines */ { if (count > priv->row) { priv->row = 0; } else { priv->row -= count; } lcd_set_curpos(priv); } break; case SLCDCODE_DOWN: /* Cursor down by N lines */ { priv->row += count; if (priv->row >= HT16K33_MAX_ROW) { priv->row = HT16K33_MAX_ROW - 1; } lcd_set_curpos(priv); } break; case SLCDCODE_HOME: /* Cursor home */ { priv->col = 0; lcd_set_curpos(priv); } break; case SLCDCODE_END: /* Cursor end */ { priv->col = HT16K33_MAX_COL - 1; lcd_set_curpos(priv); } break; case SLCDCODE_PAGEUP: /* Cursor up by N pages */ case SLCDCODE_PAGEDOWN: /* Cursor down by N pages */ break; /* Not supportable on this SLCD */ /* Blinking */ case SLCDCODE_BLINKSTART: /* Start blinking with current cursor * position */ ht16k33_write_cmd(priv, 0, HT16K33_DISPLAY_SETUP | DISPLAY_SETUP_BLINK_2HZ); break; case SLCDCODE_BLINKEND: /* End blinking after the current cursor * position */ case SLCDCODE_BLINKOFF: /* Turn blinking off */ ht16k33_write_cmd(priv, 0, HT16K33_DISPLAY_SETUP | DISPLAY_SETUP_BLINK_OFF); break; /* Not implemented */ /* These are actually unreportable errors */ default: case SLCDCODE_NORMAL: /* Not a special keycode */ break; } } /**************************************************************************** * Name: lcd_getstream * * Description: * Get one character from the LCD codec stream. * ****************************************************************************/ static int lcd_getstream(FAR struct lib_instream_s *instream) { FAR struct lcd_instream_s *lcdstream = (FAR struct lcd_instream_s *)instream; if (lcdstream->nbytes > 0) { lcdstream->nbytes--; lcdstream->stream.nget++; return (int)*lcdstream->buffer++; } return EOF; } /**************************************************************************** * Name: lcd_init * * Description: * perform the initialization sequence to get the LCD into a known state. * ****************************************************************************/ static void lcd_init(FAR struct ht16k33_dev_s *priv) { uint8_t data; int i; for (i = 0; i < CONFIG_LCD_HT16K33_NUMBER_MODULES; i++) { /* Initialize the Display: Turn ON Oscillator */ data = HT16K33_SYSTEM_SETUP | SYSTEM_SETUP_OSC_ON; ht16k33_write_cmd(priv, i, data); /* Clear display */ ht16k33_clear_display(priv); /* Display ON */ data = HT16K33_DISPLAY_SETUP | DISPLAY_SETUP_DISP_ON; ht16k33_write_cmd(priv, i, data); } } /**************************************************************************** * Name: lcd_curpos_to_fpos * * Description: * Convert a screen cursor pos (row,col) to a file logical offset. This * includes 'synthesized' line feeds at the end of screen lines. * ****************************************************************************/ static void lcd_curpos_to_fpos(FAR struct ht16k33_dev_s *priv, uint8_t row, uint8_t col, FAR off_t *fpos) { /* the logical file position is the linear position plus any synthetic LF */ *fpos = (row * HT16K33_MAX_COL) + col + row; } /**************************************************************************** * Name: ht16k33_open * * Description: * This function is called whenever the HT16K33 device is opened. * ****************************************************************************/ static int ht16k33_open(FAR struct file *filep) { return OK; } /**************************************************************************** * Name: ht16k33_close * * Description: * This routine is called when the LM-75 device is closed. * ****************************************************************************/ static int ht16k33_close(FAR struct file *filep) { return OK; } /**************************************************************************** * Name: ht16k33_read ****************************************************************************/ static ssize_t ht16k33_read(FAR struct file *filep, FAR char *buffer, size_t buflen) { return -ENOSYS; } /**************************************************************************** * Name: ht16k33_write ****************************************************************************/ static ssize_t ht16k33_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) { FAR struct inode *inode = filep->f_inode; FAR struct ht16k33_dev_s *priv = inode->i_private; struct lcd_instream_s instream; struct slcdstate_s state; enum slcdret_e result; uint8_t ch; uint8_t count; nxsem_wait(&priv->sem_excl); /* Initialize the stream for use with the SLCD CODEC */ instream.stream.get = lcd_getstream; instream.stream.nget = 0; instream.buffer = buffer; instream.nbytes = buflen; /* Now decode and process every byte in the input buffer */ memset(&state, 0, sizeof(struct slcdstate_s)); while ((result = slcd_decode(&instream.stream, &state, &ch, &count)) != SLCDRET_EOF) { /* Is there some pending scroll? */ if (priv->pendscroll) { lcd_scroll_up(priv); priv->pendscroll = false; } if (result == SLCDRET_CHAR) /* A normal character was returned */ { /* Check for ASCII control characters */ if (ch == ASCII_TAB) { /* TODO: define what TAB should do */ } else if (ch == ASCII_VT) { /* Turn the backlight on */ /* TODO: lcd_backlight(priv, true); */ } else if (ch == ASCII_FF) { /* Turn the backlight off */ /* TODO: lcd_backlight(priv, false); */ } else if (ch == ASCII_CR) { /* Perform a Home */ priv->col = 0; lcd_set_curpos(priv); } else if (ch == ASCII_SO) { /* TODO: We don't have cursor */ } else if (ch == ASCII_SI) { /* Perform the re-initialize */ lcd_init(priv); priv->row = 0; priv->col = 0; } else if (ch == ASCII_LF) { /* unixian line term; go to start of next line */ priv->row += 1; if (priv->row >= HT16K33_MAX_ROW) { priv->pendscroll = true; priv->row = HT16K33_MAX_ROW - 1; } priv->col = 0; lcd_set_curpos(priv); } else if (ch == ASCII_BS) { /* Perform the backward deletion */ lcd_codec_action(priv, SLCDCODE_BACKDEL, 1); } else if (ch == ASCII_DEL) { /* Perform the forward deletion */ lcd_codec_action(priv, SLCDCODE_FWDDEL, 1); } else { /* Just print it! */ lcd_putdata(priv, ch); } } else /* (result == SLCDRET_SPEC) */ /* A special SLCD action was returned */ { lcd_codec_action(priv, (enum slcdcode_e)ch, count); } } /* Wherever we wound up, update our logical file pos to reflect it */ lcd_curpos_to_fpos(priv, priv->row, priv->col, &filep->f_pos); nxsem_post(&priv->sem_excl); return buflen; } /**************************************************************************** * Name: ht16k33_seek * * Description: * Seek the logical file pointer to the specified position. This is * probably not very interesting except possibly for (SEEK_SET, 0) to * rewind the pointer for a subsequent read(). * The file pointer is logical, and includes synthesized LF chars at the * end of the display lines. * ****************************************************************************/ static off_t ht16k33_seek(FAR struct file *filep, off_t offset, int whence) { FAR struct inode *inode = filep->f_inode; FAR struct ht16k33_dev_s *priv = (FAR struct ht16k33_dev_s *)inode->i_private; off_t maxpos; off_t pos; nxsem_wait(&priv->sem_excl); maxpos = HT16K33_MAX_ROW * HT16K33_MAX_COL + (HT16K33_MAX_ROW - 1); pos = filep->f_pos; switch (whence) { case SEEK_CUR: pos += offset; if (pos > maxpos) { pos = maxpos; } else if (pos < 0) { pos = 0; } filep->f_pos = pos; break; case SEEK_SET: pos = offset; if (pos > maxpos) { pos = maxpos; } else if (pos < 0) { pos = 0; } filep->f_pos = pos; break; case SEEK_END: pos = maxpos + offset; if (pos > maxpos) { pos = maxpos; } else if (pos < 0) { pos = 0; } filep->f_pos = pos; break; default: /* Return EINVAL if the whence argument is invalid */ pos = (off_t)-EINVAL; break; } nxsem_post(&priv->sem_excl); return pos; } /**************************************************************************** * Name: ht16k33_ioctl * * Description: * Perform device operations that are outside the standard I/O model. * ****************************************************************************/ static int ht16k33_ioctl(FAR struct file *filep, int cmd, unsigned long arg) { switch (cmd) { case SLCDIOC_GETATTRIBUTES: /* Get the attributes of the SLCD */ { FAR struct slcd_attributes_s *attr = (FAR struct slcd_attributes_s *)((uintptr_t)arg); lcdinfo("SLCDIOC_GETATTRIBUTES:\n"); if (!attr) { return -EINVAL; } attr->nrows = HT16K33_MAX_ROW; attr->ncolumns = HT16K33_MAX_COL; attr->nbars = 0; attr->maxcontrast = 0; attr->maxbrightness = 16; /* 'brightness' for us is the backlight */ } break; case SLCDIOC_CURPOS: /* Get the SLCD cursor position */ { FAR struct inode *inode = filep->f_inode; FAR struct ht16k33_dev_s *priv = (FAR struct ht16k33_dev_s *)inode->i_private; FAR struct slcd_curpos_s *attr = (FAR struct slcd_curpos_s *)((uintptr_t)arg); attr->row = priv->row; attr->column = priv->col; } break; case SLCDIOC_GETBRIGHTNESS: /* Get the current brightness setting */ { FAR struct inode *inode = filep->f_inode; FAR struct ht16k33_dev_s *priv = (FAR struct ht16k33_dev_s *)inode->i_private; nxsem_wait(&priv->sem_excl); *(FAR int *)((uintptr_t)arg) = 1; /* Hardcoded */ nxsem_post(&priv->sem_excl); } break; case SLCDIOC_SETBRIGHTNESS: /* Set the brightness to a new value */ { FAR struct inode *inode = filep->f_inode; FAR struct ht16k33_dev_s *priv = (FAR struct ht16k33_dev_s *)inode->i_private; nxsem_wait(&priv->sem_excl); ht16k33_setcontrast(priv, 0, (uint8_t)arg); nxsem_post(&priv->sem_excl); } break; case SLCDIOC_SETBAR: /* Set bars on a bar display */ case SLCDIOC_GETCONTRAST: /* Get the current contrast setting */ case SLCDIOC_SETCONTRAST: /* Set the contrast to a new value */ default: return -ENOTTY; } return OK; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: ht16k33_register * * Description: * Register the HT16K33 character device as 'devpath' * * Input Parameters: * devno - The device number to register. E.g., "/dev/slcd0" * i2c - An instance of the I2C interface to use to communicate with * HT16K33 * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ int ht16k33_register(int devno, FAR struct i2c_master_s *i2c) { FAR struct ht16k33_dev_s *priv; char devname[DEVNAME_FMTLEN]; int ret; /* Initialize the HT16K33 device structure */ priv = (FAR struct ht16k33_dev_s *) kmm_malloc(sizeof(struct ht16k33_dev_s)); if (!priv) { snerr("ERROR: Failed to allocate instance\n"); return -ENOMEM; } /* Setup priv with initial values */ priv->i2c = i2c; priv->col = 0; priv->row = 0; priv->pendscroll = false; nxsem_init(&priv->sem_excl, 0, 1); /* Initialize the display */ lcd_init(priv); /* Create the character device name */ snprintf(devname, DEVNAME_FMTLEN, DEVNAME_FMT, devno); /* Register the driver */ ret = register_driver(devname, &g_ht16k33fops, 0666, priv); if (ret < 0) { snerr("ERROR: Failed to register driver: %d\n", ret); kmm_free(priv); } return ret; } #endif /* CONFIG_SPI && CONFIG_HT16K33 */