zephyr/drivers/auxdisplay/auxdisplay_serlcd.c

434 lines
12 KiB
C

/*
* Copyright (c) 2023 Jan Henke <Jan.Henke@taujhe.de>
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT sparkfun_serlcd
#include <stdlib.h>
#include <string.h>
#include <zephyr/device.h>
#include <zephyr/devicetree.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/auxdisplay.h>
#include <zephyr/kernel.h>
#include <zephyr/sys/util.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(auxdisplay_serlcd, CONFIG_AUXDISPLAY_LOG_LEVEL);
/*
* | in ASCII, used to begin a display command
*/
#define SERLCD_BEGIN_COMMAND 0x7C
/*
* special command for the underlying display controller
*/
#define SERLCD_BEGIN_SPECIAL_COMMAND 0xFE
/*
* maximum amount of custom chars the display supports
*/
#define SERLCD_CUSTOM_CHAR_MAX_COUNT 8
/*
* height of a custom char in bits
*/
#define SERLCD_CUSTOM_CHAR_HEIGHT 8
/*
* width of a custom char in bits
*/
#define SERLCD_CUSTOM_CHAR_WIDTH 5
/*
* char code for the first custom char
*/
#define SERLCD_CUSTOM_CHAR_INDEX_BASE 0x08
/*
* bitmask for custom character detection
*/
#define SERLCD_CUSTOM_CHAR_BITMASK 0xf8
/*
* bit to set in the display control special command to indicate the display should be powered on
*/
#define SERLCD_DISPLAY_CONTROL_POWER_BIT BIT(2)
/*
* bit to set in the display control special command to indicate the cursor should be displayed
*/
#define SERLCD_DISPLAY_CONTROL_CURSOR_BIT BIT(1)
/*
* bit to set in the display control special command to indicate the cursor should be blinking
*/
#define SERLCD_DISPLAY_CONTROL_BLINKING_BIT BIT(0)
struct auxdisplay_serlcd_data {
bool power;
bool cursor;
bool blinking;
uint16_t cursor_x;
uint16_t cursor_y;
};
struct auxdisplay_serlcd_config {
struct auxdisplay_capabilities capabilities;
struct i2c_dt_spec bus;
uint16_t command_delay_ms;
uint16_t special_command_delay_ms;
};
enum auxdisplay_serlcd_command {
SERLCD_COMMAND_SET_CUSTOM_CHAR = 0x1B,
SERLCD_COMMAND_WRITE_CUSTOM_CHAR = 0x23,
SERLCD_COMMAND_CLEAR = 0x2D,
};
enum auxdisplay_serlcd_special_command {
SERLCD_SPECIAL_RETURN_HOME = 0x02,
SERLCD_SPECIAL_DISPLAY_CONTROL = 0x08,
SERLCD_SPECIAL_SET_DD_RAM_ADDRESS = 0x80,
};
static int auxdisplay_serlcd_send_command(const struct device *dev,
const enum auxdisplay_serlcd_command command)
{
const struct auxdisplay_serlcd_config *config = dev->config;
const uint8_t buffer[2] = {SERLCD_BEGIN_COMMAND, command};
int rc = i2c_write_dt(&config->bus, buffer, sizeof(buffer));
k_sleep(K_MSEC(config->command_delay_ms));
return rc;
}
static int
auxdisplay_serlcd_send_special_command(const struct device *dev,
const enum auxdisplay_serlcd_special_command command)
{
const struct auxdisplay_serlcd_config *config = dev->config;
const uint8_t buffer[2] = {SERLCD_BEGIN_SPECIAL_COMMAND, command};
int rc = i2c_write_dt(&config->bus, buffer, sizeof(buffer));
k_sleep(K_MSEC(config->special_command_delay_ms));
return rc;
}
static int auxdisplay_serlcd_send_display_state(const struct device *dev,
const struct auxdisplay_serlcd_data *data)
{
uint8_t command = SERLCD_SPECIAL_DISPLAY_CONTROL;
if (data->power) {
command |= SERLCD_DISPLAY_CONTROL_POWER_BIT;
}
if (data->cursor) {
command |= SERLCD_DISPLAY_CONTROL_CURSOR_BIT;
}
if (data->blinking) {
command |= SERLCD_DISPLAY_CONTROL_BLINKING_BIT;
}
return auxdisplay_serlcd_send_special_command(dev, command);
}
static int auxdisplay_serlcd_display_on(const struct device *dev)
{
struct auxdisplay_serlcd_data *data = dev->data;
data->power = true;
return auxdisplay_serlcd_send_display_state(dev, data);
}
static int auxdisplay_serlcd_display_off(const struct device *dev)
{
struct auxdisplay_serlcd_data *data = dev->data;
data->power = false;
return auxdisplay_serlcd_send_display_state(dev, data);
}
static int auxdisplay_serlcd_cursor_set_enabled(const struct device *dev, bool enable)
{
struct auxdisplay_serlcd_data *data = dev->data;
data->cursor = enable;
return auxdisplay_serlcd_send_display_state(dev, data);
}
static int auxdisplay_serlcd_position_blinking_set_enabled(const struct device *dev, bool enable)
{
struct auxdisplay_serlcd_data *data = dev->data;
data->blinking = enable;
return auxdisplay_serlcd_send_display_state(dev, data);
}
static int auxdisplay_serlcd_cursor_position_set(const struct device *dev,
enum auxdisplay_position type, int16_t x,
int16_t y)
{
static const uint8_t row_offsets[] = {0x00, 0x40, 0x14, 0x54};
const struct auxdisplay_serlcd_config *config = dev->config;
const struct auxdisplay_capabilities capabilities = config->capabilities;
const uint16_t columns = capabilities.columns;
const uint16_t rows = capabilities.rows;
struct auxdisplay_serlcd_data *data = dev->data;
if (type == AUXDISPLAY_POSITION_ABSOLUTE) {
/*
* shortcut for (0,0) position
*/
if (x == 0 && y == 0) {
data->cursor_x = x;
data->cursor_y = y;
return auxdisplay_serlcd_send_special_command(dev,
SERLCD_SPECIAL_RETURN_HOME);
}
/*
* bounds checking
*/
if (x < 0 || x >= columns) {
return -EINVAL;
}
if (y < 0 || y >= rows) {
return -EINVAL;
}
data->cursor_x = x;
data->cursor_y = y;
const uint8_t cursor_address = x + row_offsets[y];
return auxdisplay_serlcd_send_special_command(
dev, SERLCD_SPECIAL_SET_DD_RAM_ADDRESS | cursor_address);
} else if (type == AUXDISPLAY_POSITION_RELATIVE) {
/*
* clip relative move to display dimensions
*/
const int new_x = (data->cursor_x + x) % columns;
const int new_y = (data->cursor_y + y + x / columns) % rows;
const uint16_t column = new_x < 0 ? new_x + columns : new_x;
const uint16_t row = new_y < 0 ? new_y + rows : new_y;
data->cursor_x = column;
data->cursor_y = row;
const uint8_t cursor_address = column + row_offsets[row];
return auxdisplay_serlcd_send_special_command(
dev, SERLCD_SPECIAL_SET_DD_RAM_ADDRESS | cursor_address);
}
/*
* other types of movement are not implemented/supported
*/
return -ENOSYS;
}
static int auxdisplay_serlcd_cursor_position_get(const struct device *dev, int16_t *x, int16_t *y)
{
const struct auxdisplay_serlcd_data *data = dev->data;
*x = (int16_t)data->cursor_x;
*y = (int16_t)data->cursor_y;
return 0;
}
static int auxdisplay_serlcd_capabilities_get(const struct device *dev,
struct auxdisplay_capabilities *capabilities)
{
const struct auxdisplay_serlcd_config *config = dev->config;
memcpy(capabilities, &config->capabilities, sizeof(struct auxdisplay_capabilities));
return 0;
}
static int auxdisplay_serlcd_clear(const struct device *dev)
{
const struct auxdisplay_serlcd_config *config = dev->config;
int rc = auxdisplay_serlcd_send_command(dev, SERLCD_COMMAND_CLEAR);
k_sleep(K_MSEC(config->command_delay_ms));
return rc;
}
static int auxdisplay_serlcd_custom_character_set(const struct device *dev,
struct auxdisplay_character *character)
{
const struct auxdisplay_serlcd_config *config = dev->config;
int rc;
/*
* only indexes 0..7 are supported
*/
const uint8_t char_index = character->index;
if (char_index > (SERLCD_CUSTOM_CHAR_MAX_COUNT - 1)) {
return -EINVAL;
}
/*
* custom characters are accessible via char codes 0x08..0x0f
*/
character->character_code = SERLCD_CUSTOM_CHAR_INDEX_BASE | char_index;
rc = auxdisplay_serlcd_send_command(dev, SERLCD_COMMAND_SET_CUSTOM_CHAR + char_index);
if (!rc) {
return rc;
}
/*
* the display expects the custom character as 8 lines of 5 bit each, shades are not
* supported
*/
for (int l = 0; l < SERLCD_CUSTOM_CHAR_HEIGHT; ++l) {
uint8_t buffer = 0;
for (int i = 0; i < SERLCD_CUSTOM_CHAR_WIDTH; ++i) {
if (character->data[(l * 5) + i]) {
buffer |= BIT(4 - i);
}
}
rc = i2c_write_dt(&config->bus, &buffer, sizeof(buffer));
if (!rc) {
return rc;
}
}
return rc;
}
static void auxdisplay_serlcd_advance_current_position(const struct device *dev)
{
const struct auxdisplay_serlcd_config *config = dev->config;
struct auxdisplay_serlcd_data *data = dev->data;
++(data->cursor_x);
if (data->cursor_x >= config->capabilities.columns) {
data->cursor_x = 0;
++(data->cursor_y);
}
if (data->cursor_y >= config->capabilities.rows) {
data->cursor_y = 0;
}
}
static int auxdisplay_serlcd_write(const struct device *dev, const uint8_t *text, uint16_t len)
{
const struct auxdisplay_serlcd_config *config = dev->config;
int rc = 0;
/*
* the display wraps around by itself, just write the text and update the position data
*/
for (int i = 0; i < len; ++i) {
uint8_t character = text[i];
/*
* customer characters require a special command, so check for custom char
*/
if ((character & SERLCD_CUSTOM_CHAR_BITMASK) == SERLCD_CUSTOM_CHAR_INDEX_BASE) {
const uint8_t command = SERLCD_COMMAND_WRITE_CUSTOM_CHAR +
(character & ~SERLCD_CUSTOM_CHAR_BITMASK);
rc = auxdisplay_serlcd_send_command(dev, command);
if (!rc) {
return rc;
}
auxdisplay_serlcd_advance_current_position(dev);
} else if (character == SERLCD_BEGIN_COMMAND ||
character == SERLCD_BEGIN_SPECIAL_COMMAND) {
/*
* skip these characters in text, as they have a special meaning, if
* required a custom character can be used as replacement
*/
continue;
} else {
rc = i2c_write_dt(&config->bus, text, len);
if (!rc) {
return rc;
}
auxdisplay_serlcd_advance_current_position(dev);
}
}
return rc;
}
static int auxdisplay_serlcd_init(const struct device *dev)
{
const struct auxdisplay_serlcd_config *config = dev->config;
struct auxdisplay_serlcd_data *data = dev->data;
/*
* Initialize our data structure
*/
data->power = true;
if (!device_is_ready(config->bus.bus)) {
return -ENODEV;
}
auxdisplay_serlcd_clear(dev);
return 0;
}
static const struct auxdisplay_driver_api auxdisplay_serlcd_auxdisplay_api = {
.display_on = auxdisplay_serlcd_display_on,
.display_off = auxdisplay_serlcd_display_off,
.cursor_set_enabled = auxdisplay_serlcd_cursor_set_enabled,
.position_blinking_set_enabled = auxdisplay_serlcd_position_blinking_set_enabled,
.cursor_position_set = auxdisplay_serlcd_cursor_position_set,
.cursor_position_get = auxdisplay_serlcd_cursor_position_get,
.capabilities_get = auxdisplay_serlcd_capabilities_get,
.clear = auxdisplay_serlcd_clear,
.custom_character_set = auxdisplay_serlcd_custom_character_set,
.write = auxdisplay_serlcd_write,
};
#define AUXDISPLAY_SERLCD_INST(inst) \
static const struct auxdisplay_serlcd_config auxdisplay_serlcd_config_##inst = { \
.capabilities = { \
.columns = DT_INST_PROP(inst, columns), \
.rows = DT_INST_PROP(inst, rows), \
.mode = 0, \
.brightness.minimum = AUXDISPLAY_LIGHT_NOT_SUPPORTED, \
.brightness.maximum = AUXDISPLAY_LIGHT_NOT_SUPPORTED, \
.backlight.minimum = AUXDISPLAY_LIGHT_NOT_SUPPORTED, \
.backlight.maximum = AUXDISPLAY_LIGHT_NOT_SUPPORTED, \
.custom_characters = SERLCD_CUSTOM_CHAR_MAX_COUNT, \
.custom_character_width = SERLCD_CUSTOM_CHAR_WIDTH, \
.custom_character_height = SERLCD_CUSTOM_CHAR_HEIGHT, \
}, \
.bus = I2C_DT_SPEC_INST_GET(inst), \
.command_delay_ms = DT_INST_PROP(inst, command_delay_ms), \
.special_command_delay_ms = DT_INST_PROP(inst, special_command_delay_ms), \
}; \
\
static struct auxdisplay_serlcd_data auxdisplay_serlcd_data_##inst; \
\
DEVICE_DT_INST_DEFINE(inst, &auxdisplay_serlcd_init, NULL, &auxdisplay_serlcd_data_##inst, \
&auxdisplay_serlcd_config_##inst, POST_KERNEL, \
CONFIG_AUXDISPLAY_INIT_PRIORITY, &auxdisplay_serlcd_auxdisplay_api);
DT_INST_FOREACH_STATUS_OKAY(AUXDISPLAY_SERLCD_INST)