[PATCH] video console: add a driver for lcd2s character display
From: Lars Poeschel
Date: Tue Nov 20 2012 - 07:56:09 EST
From: Lars Poeschel <poeschel@xxxxxxxxxxx>
This driver allows to use a lcd2s 20x4 character display as
a linux console output device.
Signed-off-by: Lars Poeschel <poeschel@xxxxxxxxxxx>
---
drivers/video/console/Kconfig | 10 +
drivers/video/console/Makefile | 1 +
drivers/video/console/lcd2scon.c | 396 ++++++++++++++++++++++++++++++++++++++
3 files changed, 407 insertions(+)
create mode 100644 drivers/video/console/lcd2scon.c
diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
index e2c96d0..44fc3bf 100644
--- a/drivers/video/console/Kconfig
+++ b/drivers/video/console/Kconfig
@@ -129,6 +129,16 @@ config STI_CONSOLE
machines. Say Y here to build support for it into your kernel.
The alternative is to use your primary serial port as a console.
+config LCD2S_CONSOLE
+ tristate "lcd2s 20x4 character display over I2C console"
+ depends on I2C
+ default n
+ help
+ This is a driver that lets you use the lcd2s 20x4 character display
+ from modtronix engineering as a console output device. The display
+ is a simple single color character display. You have to connect it
+ to an I2C bus.
+
config FONTS
bool "Select compiled-in fonts"
depends on FRAMEBUFFER_CONSOLE || STI_CONSOLE
diff --git a/drivers/video/console/Makefile b/drivers/video/console/Makefile
index a862e91..74d5993 100644
--- a/drivers/video/console/Makefile
+++ b/drivers/video/console/Makefile
@@ -23,6 +23,7 @@ font-objs += $(font-objs-y)
obj-$(CONFIG_DUMMY_CONSOLE) += dummycon.o
obj-$(CONFIG_SGI_NEWPORT_CONSOLE) += newport_con.o font.o
obj-$(CONFIG_STI_CONSOLE) += sticon.o sticore.o font.o
+obj-$(CONFIG_LCD2S_CONSOLE) += lcd2scon.o
obj-$(CONFIG_VGA_CONSOLE) += vgacon.o
obj-$(CONFIG_MDA_CONSOLE) += mdacon.o
obj-$(CONFIG_FRAMEBUFFER_CONSOLE) += fbcon.o bitblit.o font.o softcursor.o
diff --git a/drivers/video/console/lcd2scon.c b/drivers/video/console/lcd2scon.c
new file mode 100644
index 0000000..0d967ba
--- /dev/null
+++ b/drivers/video/console/lcd2scon.c
@@ -0,0 +1,396 @@
+/*
+ * console driver for LCD2S 4x20 character displays connected through i2c.
+ *
+ * This is a driver allowing you to use a LCD2S 4x20 from modtronix
+ * engineering as console output device.
+ *
+ * (C) 2012 by Lemonage Software GmbH
+ * Author: Lars Poeschel <poeschel@xxxxxxxxxxx>
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/kd.h>
+#include <linux/tty.h>
+#include <linux/console_struct.h>
+#include <linux/console.h>
+#include <linux/vt_kern.h>
+#include <linux/i2c.h>
+
+#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_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_FIRST 8
+#define LCD2S_LAST 9
+
+#define LCD2S_ROWS 4
+#define LCD2S_COLS 20
+
+struct lcd2s_data {
+ struct i2c_client *i2c;
+ struct consw consw;
+ int row;
+ int col;
+ unsigned int cur_blink:1;
+ unsigned int cur_ul:1;
+};
+
+#define consw_to_lcd2s_data(x) container_of(x, struct lcd2s_data, consw)
+
+static void lcd2s_set_cursor(struct lcd2s_data *lcd2s, int row, int col)
+{
+ u8 buf[] = { LCD2S_CMD_CUR_POS, row + 1, col + 1};
+
+ if (row == lcd2s->row && col == lcd2s->col)
+ return;
+
+ i2c_master_send(lcd2s->i2c, buf, sizeof(buf));
+ lcd2s->row = row;
+ lcd2s->col = col;
+}
+
+static void lcd2s_reset_cursor(struct lcd2s_data *lcd2s)
+{
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_RESET);
+ lcd2s->row = 0;
+ lcd2s->col = 0;
+}
+
+static void lcd2s_increase_cursor(struct lcd2s_data *lcd2s,
+ struct vc_data *con, int inc)
+{
+ lcd2s->col += inc;
+ if ((lcd2s->col / con->vc_cols) >= 1) {
+ lcd2s->row += (lcd2s->col / con->vc_cols);
+ lcd2s->col %= con->vc_cols;
+ }
+}
+
+static void lcd2s_cursor_ul_on(struct lcd2s_data *lcd2s)
+{
+ if (!lcd2s->cur_ul) {
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_UL_ON);
+ lcd2s->cur_ul = 1;
+ }
+}
+
+static void lcd2s_cursor_ul_off(struct lcd2s_data *lcd2s)
+{
+ if (lcd2s->cur_ul) {
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_UL_OFF);
+ lcd2s->cur_ul = 0;
+ }
+}
+
+static void lcd2s_cursor_blink_on(struct lcd2s_data *lcd2s)
+{
+ if (!lcd2s->cur_blink) {
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_BLINK_ON);
+ lcd2s->cur_blink = 1;
+ }
+}
+
+static void lcd2s_cursor_blink_off(struct lcd2s_data *lcd2s)
+{
+ if (lcd2s->cur_blink) {
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CUR_BLINK_OFF);
+ lcd2s->cur_blink = 0;
+ }
+}
+
+static const char *lcd2s_startup(void)
+{
+ return "lcd2s console";
+}
+
+
+/*
+ * init is set if console is currently allocated during init
+ */
+static void lcd2s_init(struct vc_data *con, int init)
+{
+ struct lcd2s_data *lcd2s = consw_to_lcd2s_data(con->vc_sw);
+
+ lcd2s->cur_blink = 0;
+ lcd2s->cur_ul = 0;
+
+ /* turn display on */
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_DISPLAY_ON);
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_BACKLIGHT_ON);
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CLEAR);
+ lcd2s_cursor_ul_on(lcd2s);
+ lcd2s_reset_cursor(lcd2s);
+
+ con->vc_can_do_color = 0;
+ con->vc_hi_font_mask = 0;
+
+ if (init) {
+ con->vc_rows = LCD2S_ROWS;
+ con->vc_cols = LCD2S_COLS;
+ } else
+ vc_resize(con, LCD2S_COLS, LCD2S_ROWS);
+}
+
+static void lcd2s_deinit(struct vc_data *con)
+{
+ struct lcd2s_data *lcd2s = consw_to_lcd2s_data(con->vc_sw);
+
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_DISPLAY_OFF);
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_BACKLIGHT_OFF);
+ lcd2s_cursor_blink_off(lcd2s);
+ lcd2s_cursor_ul_off(lcd2s);
+}
+
+static void lcd2s_clear(struct vc_data *con, int s_row, int s_col,
+ int height, int width)
+{
+ u8 buf[width];
+ int i;
+ struct lcd2s_data *lcd2s = consw_to_lcd2s_data(con->vc_sw);
+
+ if (width <= 0 || height <= 0)
+ return;
+
+ /* if the whole display is to clear, we have a single command */
+ if (s_col == 0 && s_row == 0 &&
+ height >= con->vc_rows - 1 && width >= con->vc_cols - 1) {
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_CLEAR);
+ return;
+ }
+
+ for (i = 0; i <= width; i++)
+ buf[i] = ' ';
+
+ for (i = s_col; i <= height; i++) {
+ lcd2s_set_cursor(lcd2s, s_row, i);
+ i2c_master_send(lcd2s->i2c, buf, width);
+ }
+}
+
+static void lcd2s_putc(struct vc_data *con, int data, int row, int col)
+{
+ struct lcd2s_data *lcd2s = consw_to_lcd2s_data(con->vc_sw);
+ u8 buf[] = {LCD2S_CMD_WRITE, data};
+
+ lcd2s_set_cursor(lcd2s, row, col);
+
+ i2c_master_send(lcd2s->i2c, buf, sizeof(buf));
+ lcd2s_increase_cursor(lcd2s, con, 1);
+}
+
+static void lcd2s_putcs(struct vc_data *con, const unsigned short *buf,
+ int len, int row, int col)
+{
+ u8 *i2c_buf;
+ int i;
+ struct lcd2s_data *lcd2s = consw_to_lcd2s_data(con->vc_sw);
+
+ i2c_buf = kzalloc(len + 1, GFP_KERNEL);
+ if (!i2c_buf)
+ return;
+
+ lcd2s_set_cursor(lcd2s, row, col);
+
+ i2c_buf[0] = LCD2S_CMD_WRITE;
+ for (i = 0; i < len ; i++)
+ i2c_buf[i + 1] = buf[i];
+
+ i2c_master_send(lcd2s->i2c, i2c_buf, len + 1);
+ kfree(i2c_buf);
+ lcd2s_increase_cursor(lcd2s, con, len);
+}
+
+static void lcd2s_cursor(struct vc_data *con, int mode)
+{
+ struct lcd2s_data *lcd2s = consw_to_lcd2s_data(con->vc_sw);
+
+ switch (mode) {
+ case CM_ERASE:
+ lcd2s_cursor_blink_off(lcd2s);
+ lcd2s_cursor_ul_off(lcd2s);
+ break;
+ case CM_MOVE:
+ case CM_DRAW:
+ lcd2s_set_cursor(lcd2s, con->vc_y, con->vc_x);
+
+ switch (con->vc_cursor_type & CUR_HWMASK) {
+ case CUR_UNDERLINE:
+ lcd2s_cursor_ul_on(lcd2s);
+ lcd2s_cursor_blink_off(lcd2s);
+ break;
+ case CUR_NONE:
+ lcd2s_cursor_blink_off(lcd2s);
+ lcd2s_cursor_ul_off(lcd2s);
+ break;
+ default:
+ lcd2s_cursor_blink_on(lcd2s);
+ lcd2s_cursor_ul_off(lcd2s);
+ break;
+ }
+ break;
+ }
+}
+
+static int lcd2s_scroll(struct vc_data *con, int top, int bot,
+ int dir, int lines)
+{
+ struct lcd2s_data *lcd2s = consw_to_lcd2s_data(con->vc_sw);
+
+ /* we can only scroll the whole display */
+ if (top == 0 && bot == con->vc_rows) {
+ while (lines--) {
+ switch (dir) {
+ case SM_UP:
+ i2c_smbus_write_byte(lcd2s->i2c,
+ LCD2S_CMD_SHIFT_UP);
+ break;
+ case SM_DOWN:
+ i2c_smbus_write_byte(lcd2s->i2c,
+ LCD2S_CMD_SHIFT_DOWN);
+ break;
+ }
+ }
+ return 0;
+ }
+ return 1;
+}
+
+static void lcd2s_bmove(struct vc_data *conp, int s_row, int s_col,
+ int d_row, int d_col, int height, int width)
+{
+}
+
+static int lcd2s_switch(struct vc_data *con)
+{
+ return 1;
+}
+
+static int lcd2s_blank(struct vc_data *con, int blank, int mode_switch)
+{
+ struct lcd2s_data *lcd2s = consw_to_lcd2s_data(con->vc_sw);
+
+ switch (blank) {
+ case 0: /* unblank */
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_DISPLAY_ON);
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_BACKLIGHT_ON);
+ break;
+ case 1: /* normal blanking */
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_DISPLAY_OFF);
+ i2c_smbus_write_byte(lcd2s->i2c, LCD2S_CMD_BACKLIGHT_OFF);
+ break;
+ }
+ return 0;
+}
+
+static int lcd2s_set_palette(struct vc_data *con, unsigned char *table)
+{
+ return -EINVAL;
+}
+
+static int lcd2s_scrolldelta(struct vc_data *con, int lines)
+{
+ return 0;
+}
+
+static int __devinit lcd2s_i2c_probe(struct i2c_client *i2c,
+ const struct i2c_device_id *id)
+{
+ struct lcd2s_data *data;
+
+ if (!i2c_check_functionality(i2c->adapter,
+ I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
+ return -EIO;
+ data = devm_kzalloc(&i2c->dev, sizeof(struct lcd2s_data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->i2c = i2c;
+ data->consw.owner = THIS_MODULE;
+ data->consw.con_startup = lcd2s_startup;
+ data->consw.con_init = lcd2s_init;
+ data->consw.con_deinit = lcd2s_deinit;
+ data->consw.con_clear = lcd2s_clear;
+ data->consw.con_putc = lcd2s_putc;
+ data->consw.con_putcs = lcd2s_putcs;
+ data->consw.con_cursor = lcd2s_cursor;
+ data->consw.con_scroll = lcd2s_scroll;
+ data->consw.con_bmove = lcd2s_bmove;
+ data->consw.con_switch = lcd2s_switch;
+ data->consw.con_blank = lcd2s_blank;
+ data->consw.con_set_palette = lcd2s_set_palette;
+ data->consw.con_scrolldelta = lcd2s_scrolldelta;
+
+ i2c_set_clientdata(i2c, data);
+
+ take_over_console(&data->consw, LCD2S_FIRST, LCD2S_LAST, 1);
+
+ return 0;
+}
+
+static __devexit int lcd2s_i2c_remove(struct i2c_client *i2c)
+{
+ struct lcd2s_data *data = i2c_get_clientdata(i2c);
+
+ /* unregister from console subsystem */
+ unregister_con_driver(&data->consw);
+ return 0;
+}
+
+static const struct i2c_device_id lcd2s_i2c_id[] = {
+ { "lcd2s", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, lcd2s_i2c_id);
+
+static struct i2c_driver lcd2s_i2c_driver = {
+ .driver = {
+ .name = "lcd2s",
+ .owner = THIS_MODULE,
+ },
+ .probe = lcd2s_i2c_probe,
+ .remove = __devexit_p(lcd2s_i2c_remove),
+ .id_table = lcd2s_i2c_id,
+};
+
+static int __init lcd2s_modinit(void)
+{
+ int ret = 0;
+
+ ret = i2c_add_driver(&lcd2s_i2c_driver);
+ if (ret != 0)
+ pr_err("Failed to register lcd2s driver\n");
+
+ return ret;
+}
+module_init(lcd2s_modinit)
+
+static void __exit lcd2s_exit(void)
+{
+ i2c_del_driver(&lcd2s_i2c_driver);
+}
+module_exit(lcd2s_exit)
+
+MODULE_DESCRIPTION("LCD2S character display console driver");
+MODULE_AUTHOR("Lars Poeschel");
+MODULE_LICENSE("GPL");
--
1.7.10.4
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