led_display: split led display support into generic and hw-dependent parts

Split the display command into generic interface and hardware-specific
realization for PDSP188x LED display found on hmi1001 and manroland
boards. Simple interface for LED displays is defined in
include/led-display.h and described in doc/README.LED_display.
Driver-specific implementation was moved into drivers/misc/pdsp188x.c
file (enabled with CONFIG_PDSP188x set).

Signed-off-by: Ilya Yanok <yanok@emcraft.com>

common/cmd_display.c

@@ -23,40 +23,32 @@
 
 #include <common.h>
 #include <command.h>
+#include <led-display.h>
 
 #undef DEBUG_DISP
 
-#define DISP_SIZE	8
-#define CWORD_CLEAR	0x80
-#define CLEAR_DELAY	(110 * 2)
-
 int do_display (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	int i;
-	int pos;
 
 	/* Clear display */
-	*((volatile char*)(CONFIG_SYS_DISP_CWORD)) = CWORD_CLEAR;
-	udelay(1000 * CLEAR_DELAY);
+	display_set(DISPLAY_CLEAR | DISPLAY_HOME);
 
 	if (argc < 2)
 		return (0);
 
-	for (pos = 0, i = 1; i < argc && pos < DISP_SIZE; i++) {
-		char *p = argv[i], c;
+	for (i = 1; i < argc; i++) {
+		char *p = argv[i];
 
-		if (i > 1) {
-			*((volatile uchar *) (CONFIG_SYS_DISP_CHR_RAM + pos++)) = ' ';
-#ifdef DEBUG_DISP
-			putc(' ');
-#endif
+		if (i > 1) { /* Insert a space between strings */
+			display_putc(' ');
 		}
 
-		while ((c = *p++) != '\0' && pos < DISP_SIZE) {
-			*((volatile uchar *) (CONFIG_SYS_DISP_CHR_RAM + pos++)) = c;
+		while ((*p)) {
 #ifdef DEBUG_DISP
-			putc(c);
+			putc(*p);
 #endif
+			display_putc(*p++);
 		}
 	}
 

doc/README.LED_display

+LED display internal API
+=======================================
+
+This README describes the LED display API.
+
+The API is defined by the include file include/led-display.h
+
+The first step in to define CONFIG_CMD_DISPLAY in the board config file.
+Then you need to provide the following functions to access LED display:
+
+void display_set(int cmd);
+
+This function should control the state of the LED display. Argument is
+an ORed combination of the following values:
+ DISPLAY_CLEAR	-- clear the display
+ DISPLAY_HOME	-- set the position to the beginning of display
+ DISPLAY_MARK	-- enable mark (decimal point), if implemented
+
+int display_putc(char c);
+
+This function should display it's parameter on the LED display in the
+current position. Returns the displayed character on success or -1 in
+case of failure.
+
+With this functions defined 'display' command will display it's
+arguments on the LED display (or clear the display if called without
+arguments).

drivers/misc/Makefile

@@ -33,6 +33,7 @@ COBJS-$(CONFIG_NS87308) += ns87308.o
 COBJS-$(CONFIG_STATUS_LED) += status_led.o
 COBJS-$(CONFIG_TWL4030_LED) += twl4030_led.o
 COBJS-$(CONFIG_FSL_PMIC) += fsl_pmic.o
+COBJS-$(CONFIG_PDSP188x) += pdsp188x.o
 
 COBJS	:= $(COBJS-y)
 SRCS	:= $(COBJS:.o=.c)

drivers/misc/pdsp188x.c

+/*
+ * Copyright 2010 Sergey Poselenov, Emcraft Systems, <sposelenov@emcraft.com>
+ * Copyright 2010 Ilya Yanok, Emcraft Systems, <yanok@emcraft.com>
+ *
+ * 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.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <common.h>
+#include <led-display.h>
+#include <asm/io.h>
+
+#ifdef CONFIG_CMD_DISPLAY
+#define CWORD_CLEAR	0x80
+#define CLEAR_DELAY	(110 * 2)
+#define DISPLAY_SIZE	8
+
+static int pos; /* Current display position */
+
+/* Handle different display commands */
+void display_set(int cmd)
+{
+	if (cmd & DISPLAY_CLEAR) {
+		out_8((unsigned char *)CONFIG_SYS_DISP_CWORD, CWORD_CLEAR);
+		udelay(1000 * CLEAR_DELAY);
+	}
+
+	if (cmd & DISPLAY_HOME) {
+		pos = 0;
+	}
+}
+
+/*
+ * Display a character at the current display position.
+ * Characters beyond the display size are ignored.
+ */
+int display_putc(char c)
+{
+	if (pos >= DISPLAY_SIZE)
+		return -1;
+
+	out_8((unsigned char *)CONFIG_SYS_DISP_CHR_RAM + pos++, c);
+
+	return c;
+}
+#endif

include/configs/hmi1001.h

@@ -352,6 +352,7 @@
 /* Display addresses						       */
 /*---------------------------------------------------------------------*/
 
+#define CONFIG_PDSP188x
 #define CONFIG_SYS_DISP_CHR_RAM	(CONFIG_SYS_DISPLAY_BASE + 0x38)
 #define CONFIG_SYS_DISP_CWORD		(CONFIG_SYS_DISPLAY_BASE + 0x30)
 

include/configs/manroland/common.h

@@ -55,6 +55,11 @@
 #define CONFIG_CMD_MII
 #define CONFIG_CMD_SNTP
 
+/*
+ * 8-symbol LED display (can be accessed with 'display' command)
+ */
+#define CONFIG_PDSP188x
+
 #define	CONFIG_TIMESTAMP	1	/* Print image info with timestamp */
 
 /*

include/led-display.h

+/*
+ * (C) Copyright 2005-2010
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * (C) Copyright 2010
+ * Sergei Poselenov, Emcraft Systems, sposelenov@emcraft.com.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#ifndef _led_display_h_
+#define _led_display_h_
+
+/* Display Commands */
+#define DISPLAY_CLEAR	0x1 /* Clear the display */
+#define DISPLAY_HOME	0x2 /* Set cursor at home position */
+#define DISPLAY_MARK	0x4 /* Enable the decimal point led, if implemented */
+
+void display_set(int cmd);
+int display_putc(char c);
+#endif