Add devmem2 backend

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>

8 files changed, 202 insertions, 6 deletions

diff --git a/Makefile b/Makefile
index 0000e8f..fc7524b 100644
--- a/Makefile
+++ b/Makefile
@@ -2,10 +2,11 @@
 
 SOURCE := \
 	compatible_devices.c \
+	devmem2.c \
 	exynos4412_gpios.c  \
 	exynos4412_gpios_data.c \
 	main.c \
-	memory.c \
+	memory_devmem2.c \
 	modem_gpios_data.c \
 	tests.c \
 
diff --git a/devmem2.c b/devmem2.c
new file mode 100644
index 0000000..967dbc2
--- /dev/null
+++ b/devmem2.c
@@ -0,0 +1,125 @@
+/*
+ * Modified from devmem2.c which has the following header:
+ */
+/*
+ * devmem2.c: Simple program to read/write from/to any location in memory.
+ *
+ *  Copyright (C) 2000, Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl)
+ *
+ *
+ * This software has been developed for the LART computing board
+ * (http://www.lart.tudelft.nl/). The development has been sponsored by
+ * the Mobile MultiMedia Communications (http://www.mmc.tudelft.nl/)
+ * and Ubiquitous Communications (http://www.ubicom.tudelft.nl/)
+ * projects.
+ *
+ * The author can be reached at:
+ *
+ *  Jan-Derk Bakker
+ *  Information and Communication Theory Group
+ *  Faculty of Information Technology and Systems
+ *  Delft University of Technology
+ *  P.O. Box 5031
+ *  2600 GA Delft
+ *  The Netherlands
+ *
+ *
+ * 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
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <termios.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+
+#include "devmem2.h"
+
+#define FATAL do { fprintf(stderr, "Error at line %d, file %s (%d) [%s]\n", \
+  __LINE__, __FILE__, errno, strerror(errno)); exit(1); } while(0)
+ 
+#define MAP_SIZE 4096UL
+#define MAP_MASK (MAP_SIZE - 1)
+
+int devmem2(int debug, off_t target, int access_type,
+	    unsigned long *read_result, unsigned long *writeval)
+{
+    int fd;
+    void *map_base, *virt_addr;
+
+    if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1) FATAL;
+    if (debug)
+	    printf("/dev/mem opened.\n"); 
+    fflush(stdout);
+    
+    /* Map one page */
+    map_base = mmap(0, MAP_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, target & ~MAP_MASK);
+    if(map_base == (void *) -1) FATAL;
+    if (debug)
+	    printf("Memory mapped at address %p.\n", map_base); 
+    fflush(stdout);
+    
+    virt_addr = map_base + (target & MAP_MASK);
+    switch(access_type) {
+		case 'b':
+			*read_result = *((unsigned char *) virt_addr);
+			break;
+		case 'h':
+			*read_result = *((unsigned short *) virt_addr);
+			break;
+		case 'w':
+			*read_result = *((unsigned long *) virt_addr);
+			break;
+		default:
+			fprintf(stderr, "Illegal data type '%c'.\n", access_type);
+			exit(2);
+	}
+    if (debug)
+	    printf("Value at address 0x%X (%p): 0x%X\n", target, virt_addr,
+		   *read_result); 
+    fflush(stdout);
+
+	if(writeval != NULL) {
+		switch(access_type) {
+			case 'b':
+				*((unsigned char *) virt_addr) = *writeval;
+				*read_result = *((unsigned char *) virt_addr);
+				break;
+			case 'h':
+				*((unsigned short *) virt_addr) = *writeval;
+				*read_result = *((unsigned short *) virt_addr);
+				break;
+			case 'w':
+				*((unsigned long *) virt_addr) = *writeval;
+				*read_result = *((unsigned long *) virt_addr);
+				break;
+		}
+		if (debug)
+			printf("Written 0x%X; readback 0x%X\n", *writeval, *read_result); 
+		fflush(stdout);
+	}
+	
+	if(munmap(map_base, MAP_SIZE) == -1) FATAL;
+    close(fd);
+    return 0;
+}
+
diff --git a/devmem2.h b/devmem2.h
new file mode 100644
index 0000000..41afa5c
--- /dev/null
+++ b/devmem2.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2021 Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
+ *
+ * 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 3 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, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef DEVMEM2_H
+#define DEVMEM2_H
+int devmem2(int debug, off_t target, int access_type,
+	    unsigned long *read_result, unsigned long *writeval);
+#endif /* DEVMEM2_H */
diff --git a/exynos4412_gpios_data.c b/exynos4412_gpios_data.c
index deed252..9b82cff 100644
--- a/exynos4412_gpios_data.c
+++ b/exynos4412_gpios_data.c
@@ -385,7 +385,7 @@ int decode_gpio_data(int debug, char *bank, uint32_t gpio_offset,
 	struct gpio_bank_data *gpio_bank_data;
 	struct gpio_register_data *gpio_register_data;
 	unsigned int addr;
-	unsigned int register_value;
+	unsigned long register_value;
 	int rc;
 
 	gpio_bank_data = get_gpio_bank_data(bank);
@@ -420,7 +420,7 @@ int decode_gpio_data(int debug, char *bank, uint32_t gpio_offset,
 	}
 
 	if (debug)
-		printf("%s: %s @ 0x%x = 0x%x\n", __func__, bank,
+		printf("%s: %s @ 0x%x = 0x%lx\n", __func__, bank,
 		       addr, register_value);
 
 	return gpio_register_data->get_value(register_value, gpio_offset);
diff --git a/main.c b/main.c
index e608022..e6b88f8 100644
--- a/main.c
+++ b/main.c
@@ -124,7 +124,7 @@ int main(int argc, char *argv[])
 {
 	struct memory_mapping *memory_mapping;
 
-	int debug = 1;
+	int debug = 0;
 	int rc;
 
 	assert(argc >= 1);
diff --git a/memory.c b/memory.c
index a162b1d..f5da796 100644
--- a/memory.c
+++ b/memory.c
@@ -211,7 +211,7 @@ off_t *phys_to_virt(int debug, struct memory_mapping *memory_mapping, off_t phys
 }
 
 int read_word(int debug, struct memory_mapping *memory_mapping,
-	      off_t addr, unsigned int *result)
+	      off_t addr, unsigned long *result)
 {
 	off_t *virt_addr;
 
diff --git a/memory.h b/memory.h
index 5ba91bf..ff2591f 100644
--- a/memory.h
+++ b/memory.h
@@ -24,6 +24,6 @@ int init_memory_mapping(int debug, struct memory_mapping **memory_mapping_pp);
 int exit_memory_mapping(int debug, struct memory_mapping *memory_mapping);
 
 int read_word(int debug, struct memory_mapping *memory_mapping,
-	      off_t addr, unsigned int *result);
+	      off_t addr, unsigned long *result);
 
 #endif /* MEMORY_H */
diff --git a/memory_devmem2.c b/memory_devmem2.c
new file mode 100644
index 0000000..ac25fc2
--- /dev/null
+++ b/memory_devmem2.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2021 Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
+ *
+ * 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 3 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, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#include "devmem2.h"
+#include "memory.h"
+
+int init_memory_mapping(int debug, struct memory_mapping **memory_mapping_pp)
+{
+	return 0;
+}
+
+int read_word(int debug, struct memory_mapping *memory_mapping,
+	      off_t addr, unsigned long *result)
+{
+	int rc;
+
+	rc = devmem2(debug, addr, 'w', result, NULL);
+	if (rc)
+		printf("%s: devmem2 failed with error %d\n", __func__, rc);
+
+	return rc;
+}