commands: add i2c commands

theses commands allow low level access to i2c bus and can be useful
to setup an i2c device without having to add code, compile and flash
barebox.

Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 223 insertions, 0 deletions

diff --git a/commands/Kconfig b/commands/Kconfig
index 0c09f91643..0ea32d963b 100644
--- a/commands/Kconfig
+++ b/commands/Kconfig
@@ -314,4 +314,12 @@ config CMD_UNLZO
 	  Say yes here to get the unlzo command. lzo is a fast compression
 	  algorithm by Markus Franz Xaver Johannes Oberhumer.
 
+config CMD_I2C
+	bool
+	depends on I2C
+	prompt "i2c commands"
+	help
+	  include i2c_probe, i2c_read and i2c_write commands to communicate
+	  on i2c bus.
+
 endmenu
diff --git a/commands/Makefile b/commands/Makefile
index 74b099414f..3eef5debf3 100644
--- a/commands/Makefile
+++ b/commands/Makefile
@@ -48,3 +48,4 @@ obj-$(CONFIG_CMD_BMP)		+= bmp.o
 obj-$(CONFIG_USB_GADGET_DFU)	+= dfu.o
 obj-$(CONFIG_CMD_GPIO)		+= gpio.o
 obj-$(CONFIG_CMD_UNLZO)		+= unlzo.o
+obj-$(CONFIG_CMD_I2C)		+= i2c.o
diff --git a/commands/i2c.c b/commands/i2c.c
new file mode 100644
index 0000000000..d38e779acb
--- /dev/null
+++ b/commands/i2c.c
@@ -0,0 +1,214 @@
+/*
+ * i2c.c - i2c commands
+ *
+ * Copyright (c) 2010 Eric Bénard <eric@eukrea.Com>, Eukréa Electromatique
+ *
+ * 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 <common.h>
+#include <command.h>
+#include <errno.h>
+#include <malloc.h>
+#include <getopt.h>
+#include <i2c/i2c.h>
+
+static int do_i2c_probe(struct command *cmdtp, int argc, char *argv[])
+{
+	struct i2c_adapter *adapter;
+	struct i2c_client client;
+	int startaddr = -1, stopaddr = -1, addr, ret;
+	u8 reg;
+
+	if (argc < 4)
+		return COMMAND_ERROR_USAGE;
+
+	adapter = i2c_get_adapter(simple_strtoul(argv[1], NULL, 0));
+	if (!adapter)
+		return -ENODEV;
+	client.adapter = adapter;
+
+	startaddr = simple_strtol(argv[2], NULL, 0);
+	stopaddr = simple_strtol(argv[3], NULL, 0);
+	if ((startaddr == -1) || (stopaddr == -1) || (startaddr > stopaddr))
+		return COMMAND_ERROR_USAGE;
+
+	if (stopaddr > 0x7F)
+		stopaddr = 0x7F;
+
+	printf("probing i2c range 0X%02x - 0x%02x :\n", startaddr, stopaddr);
+	for (addr = startaddr; addr <= stopaddr; addr++) {
+		client.addr = addr;
+		ret = i2c_write_reg(&client, 0x00, &reg, 0);
+		if (ret == 0)
+			printf("0x%02x ", addr);
+	}
+	printf("\n");
+	return 0;
+}
+
+static const __maybe_unused char cmd_i2c_probe_help[] =
+"Usage: i2c_probe bus 0xstartaddr 0xstopaddr\n"
+"probe a range of i2c addresses.\n";
+
+BAREBOX_CMD_START(i2c_probe)
+	.cmd		= do_i2c_probe,
+	.usage		= "probe for an i2c device",
+	BAREBOX_CMD_HELP(cmd_i2c_probe_help)
+BAREBOX_CMD_END
+
+static int do_i2c_write(struct command *cmdtp, int argc, char *argv[])
+{
+	struct i2c_adapter *adapter = NULL;
+	struct i2c_client client;
+	int addr = -1, reg = -1, count = -1, verbose = 0, ret, opt, i, bus = 0;
+	u8 *buf;
+
+	while ((opt = getopt(argc, argv, "a:b:r:v")) > 0) {
+		switch (opt) {
+		case 'a':
+			addr = simple_strtol(optarg, NULL, 0);
+			break;
+		case 'r':
+			reg = simple_strtol(optarg, NULL, 0);
+			break;
+		case 'b':
+			bus = simple_strtoul(optarg, NULL, 0);
+			break;
+		case 'v':
+			verbose = 1;
+			break;
+		}
+	}
+
+	count = argc - optind;
+
+	if ((addr < 0) || (reg < 0) || (count == 0) || (addr > 0x7F))
+		return COMMAND_ERROR_USAGE;
+
+	adapter = i2c_get_adapter(bus);
+	if (!adapter) {
+		printf("i2c bus %d not found\n", bus);
+		return -ENODEV;
+	}
+
+	client.adapter = adapter;
+	client.addr = addr;
+
+	buf = xmalloc(count);
+	for (i = 0; i < count; i++)
+		*(buf + i) = (char) simple_strtol(argv[optind+i], NULL, 16);
+
+	ret = i2c_write_reg(&client, reg, buf, count);
+	if (ret != count)
+		goto out;
+	ret = 0;
+
+	if (verbose) {
+		printf("wrote %i bytes starting at reg 0x%02x to i2cdev 0x%02x on bus %i\n",
+			count, reg, addr, adapter->nr);
+		for (i = 0; i < count; i++)
+			printf("0x%02x ", *(buf + i));
+		printf("\n");
+	}
+
+out:
+	free(buf);
+	return ret;
+}
+
+static const __maybe_unused char cmd_i2c_write_help[] =
+"Usage: i2c_write [OPTION] ... hexdatas\n"
+"write to i2c device.\n"
+"  -a 0x<addr>   i2c device address\n"
+"  -b <bus_num>  i2c bus number (default = 0)\n"
+"  -r 0x<reg>    start register\n";
+
+BAREBOX_CMD_START(i2c_write)
+	.cmd		= do_i2c_write,
+	.usage		= "write to an i2c device",
+	BAREBOX_CMD_HELP(cmd_i2c_write_help)
+BAREBOX_CMD_END
+
+static int do_i2c_read(struct command *cmdtp, int argc, char *argv[])
+{
+	struct i2c_adapter *adapter = NULL;
+	struct i2c_client client;
+	u8 *buf;
+	int count = -1, addr = -1, reg = -1, verbose = 0, ret, opt, bus = 0;
+
+	while ((opt = getopt(argc, argv, "a:b:c:r:v")) > 0) {
+		switch (opt) {
+		case 'a':
+			addr = simple_strtol(optarg, NULL, 0);
+			break;
+		case 'c':
+			count = simple_strtoul(optarg, NULL, 0);
+			break;
+		case 'b':
+			bus = simple_strtoul(optarg, NULL, 0);
+			break;
+		case 'r':
+			reg = simple_strtol(optarg, NULL, 0);
+			break;
+		case 'v':
+			verbose = 1;
+			break;
+		}
+	}
+
+	if ((addr < 0) || (reg < 0) || (count == 0) || (addr > 0x7F))
+		return COMMAND_ERROR_USAGE;
+
+	adapter = i2c_get_adapter(bus);
+	if (!adapter) {
+		printf("i2c bus %d not found\n", bus);
+		return -ENODEV;
+	}
+
+	client.adapter = adapter;
+	client.addr = addr;
+
+	buf = xmalloc(count);
+	ret = i2c_read_reg(&client, reg, buf, count);
+	if (ret == count) {
+		int i;
+		if (verbose)
+			printf("read %i bytes starting at reg 0x%02x from i2cdev 0x%02x on bus %i\n",
+				count, reg, addr, adapter->nr);
+		for (i = 0; i < count; i++)
+			printf("0x%02x ", *(buf + i));
+		printf("\n");
+		ret = 0;
+	}
+
+	free(buf);
+	return ret;
+}
+
+static const __maybe_unused char cmd_i2c_read_help[] =
+"Usage: i2c_read [OPTION]\n"
+"read i2c device.\n"
+"  -a 0x<addr>   i2c device address\n"
+"  -b <bus_num>  i2c bus number (default = 0)\n"
+"  -r 0x<reg>    start register\n"
+"  -c <count>    byte count\n";
+
+BAREBOX_CMD_START(i2c_read)
+	.cmd		= do_i2c_read,
+	.usage		= "read from an i2c device",
+	BAREBOX_CMD_HELP(cmd_i2c_read_help)
+BAREBOX_CMD_END