diff options
Diffstat (limited to 'drivers/auxdisplay/lcd2s.c')
| -rw-r--r-- | drivers/auxdisplay/lcd2s.c | 376 |
1 files changed, 376 insertions, 0 deletions
diff --git a/drivers/auxdisplay/lcd2s.c b/drivers/auxdisplay/lcd2s.c new file mode 100644 index 0000000000..6422be0dfe --- /dev/null +++ b/drivers/auxdisplay/lcd2s.c @@ -0,0 +1,376 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Console driver for LCD2S 4x20 character displays connected through i2c. + * The display also has a SPI interface, but the driver does not support + * this yet. + * + * This is a driver allowing you to use a LCD2S 4x20 from Modtronix + * engineering as auxdisplay character device. + * + * (C) 2019 by Lemonage Software GmbH + * Author: Lars Pöschel <poeschel@lemonage.de> + * All rights reserved. + */ +#include <linux/kernel.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/property.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/delay.h> + +#include "charlcd.h" + +#define LCD2S_CMD_CUR_MOVES_FWD 0x09 +#define LCD2S_CMD_CUR_BLINK_OFF 0x10 +#define LCD2S_CMD_CUR_UL_OFF 0x11 +#define LCD2S_CMD_DISPLAY_OFF 0x12 +#define LCD2S_CMD_CUR_BLINK_ON 0x18 +#define LCD2S_CMD_CUR_UL_ON 0x19 +#define LCD2S_CMD_DISPLAY_ON 0x1a +#define LCD2S_CMD_BACKLIGHT_OFF 0x20 +#define LCD2S_CMD_BACKLIGHT_ON 0x28 +#define LCD2S_CMD_WRITE 0x80 +#define LCD2S_CMD_MOV_CUR_RIGHT 0x83 +#define LCD2S_CMD_MOV_CUR_LEFT 0x84 +#define LCD2S_CMD_SHIFT_RIGHT 0x85 +#define LCD2S_CMD_SHIFT_LEFT 0x86 +#define LCD2S_CMD_SHIFT_UP 0x87 +#define LCD2S_CMD_SHIFT_DOWN 0x88 +#define LCD2S_CMD_CUR_ADDR 0x89 +#define LCD2S_CMD_CUR_POS 0x8a +#define LCD2S_CMD_CUR_RESET 0x8b +#define LCD2S_CMD_CLEAR 0x8c +#define LCD2S_CMD_DEF_CUSTOM_CHAR 0x92 +#define LCD2S_CMD_READ_STATUS 0xd0 + +#define LCD2S_CHARACTER_SIZE 8 + +#define LCD2S_STATUS_BUF_MASK 0x7f + +struct lcd2s_data { + struct i2c_client *i2c; + struct charlcd *charlcd; +}; + +static s32 lcd2s_wait_buf_free(const struct i2c_client *client, int count) +{ + s32 status; + + status = i2c_smbus_read_byte_data(client, LCD2S_CMD_READ_STATUS); + if (status < 0) + return status; + + while ((status & LCD2S_STATUS_BUF_MASK) < count) { + mdelay(1); + status = i2c_smbus_read_byte_data(client, + LCD2S_CMD_READ_STATUS); + if (status < 0) + return status; + } + return 0; +} + +static int lcd2s_i2c_master_send(const struct i2c_client *client, + const char *buf, int count) +{ + s32 status; + + status = lcd2s_wait_buf_free(client, count); + if (status < 0) + return status; + + return i2c_master_send(client, buf, count); +} + +static int lcd2s_i2c_smbus_write_byte(const struct i2c_client *client, u8 value) +{ + s32 status; + + status = lcd2s_wait_buf_free(client, 1); + if (status < 0) + return status; + + return i2c_smbus_write_byte(client, value); +} + +static int lcd2s_print(struct charlcd *lcd, int c) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + u8 buf[2] = { LCD2S_CMD_WRITE, c }; + + lcd2s_i2c_master_send(lcd2s->i2c, buf, sizeof(buf)); + return 0; +} + +static int lcd2s_gotoxy(struct charlcd *lcd, unsigned int x, unsigned int y) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + u8 buf[3] = { LCD2S_CMD_CUR_POS, y + 1, x + 1 }; + + lcd2s_i2c_master_send(lcd2s->i2c, buf, sizeof(buf)); + + return 0; +} + +static int lcd2s_home(struct charlcd *lcd) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_RESET); + return 0; +} + +static int lcd2s_init_display(struct charlcd *lcd) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + + /* turn everything off, but display on */ + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_DISPLAY_ON); + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_BACKLIGHT_OFF); + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_MOVES_FWD); + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_BLINK_OFF); + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_UL_OFF); + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CLEAR); + + return 0; +} + +static int lcd2s_shift_cursor(struct charlcd *lcd, enum charlcd_shift_dir dir) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + + if (dir == CHARLCD_SHIFT_LEFT) + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_MOV_CUR_LEFT); + else + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_MOV_CUR_RIGHT); + + return 0; +} + +static int lcd2s_shift_display(struct charlcd *lcd, enum charlcd_shift_dir dir) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + + if (dir == CHARLCD_SHIFT_LEFT) + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_SHIFT_LEFT); + else + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_SHIFT_RIGHT); + + return 0; +} + +static void lcd2s_backlight(struct charlcd *lcd, enum charlcd_onoff on) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + + if (on) + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_BACKLIGHT_ON); + else + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_BACKLIGHT_OFF); +} + +static int lcd2s_display(struct charlcd *lcd, enum charlcd_onoff on) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + + if (on) + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_DISPLAY_ON); + else + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_DISPLAY_OFF); + + return 0; +} + +static int lcd2s_cursor(struct charlcd *lcd, enum charlcd_onoff on) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + + if (on) + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_UL_ON); + else + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_UL_OFF); + + return 0; +} + +static int lcd2s_blink(struct charlcd *lcd, enum charlcd_onoff on) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + + if (on) + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_BLINK_ON); + else + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_BLINK_OFF); + + return 0; +} + +static int lcd2s_fontsize(struct charlcd *lcd, enum charlcd_fontsize size) +{ + return 0; +} + +static int lcd2s_lines(struct charlcd *lcd, enum charlcd_lines lines) +{ + return 0; +} + +/* + * Generator: LGcxxxxx...xx; must have <c> between '0' and '7', + * representing the numerical ASCII code of the redefined character, + * and <xx...xx> a sequence of 16 hex digits representing 8 bytes + * for each character. Most LCDs will only use 5 lower bits of + * the 7 first bytes. + */ +static int lcd2s_redefine_char(struct charlcd *lcd, char *esc) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + u8 buf[LCD2S_CHARACTER_SIZE + 2] = { LCD2S_CMD_DEF_CUSTOM_CHAR }; + u8 value; + int shift, i; + + if (!strchr(esc, ';')) + return 0; + + esc++; + + buf[1] = *(esc++) - '0'; + if (buf[1] > 7) + return 1; + + i = 2; + shift = 0; + value = 0; + while (*esc && i < LCD2S_CHARACTER_SIZE + 2) { + int half; + + shift ^= 4; + half = hex_to_bin(*esc++); + if (half < 0) + continue; + + value |= half << shift; + if (shift == 0) { + buf[i++] = value; + value = 0; + } + } + + lcd2s_i2c_master_send(lcd2s->i2c, buf, sizeof(buf)); + return 1; +} + +static int lcd2s_clear_display(struct charlcd *lcd) +{ + struct lcd2s_data *lcd2s = lcd->drvdata; + + /* This implicitly sets cursor to first row and column */ + lcd2s_i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CLEAR); + return 0; +} + +static const struct charlcd_ops lcd2s_ops = { + .print = lcd2s_print, + .backlight = lcd2s_backlight, + .gotoxy = lcd2s_gotoxy, + .home = lcd2s_home, + .clear_display = lcd2s_clear_display, + .init_display = lcd2s_init_display, + .shift_cursor = lcd2s_shift_cursor, + .shift_display = lcd2s_shift_display, + .display = lcd2s_display, + .cursor = lcd2s_cursor, + .blink = lcd2s_blink, + .fontsize = lcd2s_fontsize, + .lines = lcd2s_lines, + .redefine_char = lcd2s_redefine_char, +}; + +static int lcd2s_i2c_probe(struct i2c_client *i2c) +{ + struct charlcd *lcd; + struct lcd2s_data *lcd2s; + int err; + + if (!i2c_check_functionality(i2c->adapter, + I2C_FUNC_SMBUS_WRITE_BYTE_DATA | + I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)) + return -EIO; + + lcd2s = devm_kzalloc(&i2c->dev, sizeof(*lcd2s), GFP_KERNEL); + if (!lcd2s) + return -ENOMEM; + + /* Test, if the display is responding */ + err = lcd2s_i2c_smbus_write_byte(i2c, LCD2S_CMD_DISPLAY_OFF); + if (err < 0) + return err; + + lcd = charlcd_alloc(); + if (!lcd) + return -ENOMEM; + + lcd->drvdata = lcd2s; + lcd2s->i2c = i2c; + lcd2s->charlcd = lcd; + + /* Required properties */ + err = device_property_read_u32(&i2c->dev, "display-height-chars", + &lcd->height); + if (err) + goto fail1; + + err = device_property_read_u32(&i2c->dev, "display-width-chars", + &lcd->width); + if (err) + goto fail1; + + lcd->ops = &lcd2s_ops; + + err = charlcd_register(lcd2s->charlcd); + if (err) + goto fail1; + + i2c_set_clientdata(i2c, lcd2s); + return 0; + +fail1: + charlcd_free(lcd2s->charlcd); + return err; +} + +static void lcd2s_i2c_remove(struct i2c_client *i2c) +{ + struct lcd2s_data *lcd2s = i2c_get_clientdata(i2c); + + charlcd_unregister(lcd2s->charlcd); + charlcd_free(lcd2s->charlcd); +} + +static const struct i2c_device_id lcd2s_i2c_id[] = { + { "lcd2s", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, lcd2s_i2c_id); + +static const struct of_device_id lcd2s_of_table[] = { + { .compatible = "modtronix,lcd2s" }, + { } +}; +MODULE_DEVICE_TABLE(of, lcd2s_of_table); + +static struct i2c_driver lcd2s_i2c_driver = { + .driver = { + .name = "lcd2s", + .of_match_table = lcd2s_of_table, + }, + .probe = lcd2s_i2c_probe, + .remove = lcd2s_i2c_remove, + .id_table = lcd2s_i2c_id, +}; +module_i2c_driver(lcd2s_i2c_driver); + +MODULE_DESCRIPTION("LCD2S character display driver"); +MODULE_AUTHOR("Lars Poeschel"); +MODULE_LICENSE("GPL"); |