[PATCH v6 3/6] commands: add i2c commands

["Eric Bénard" <eric@eukrea.com>]

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>
---
v6 :
	add log before exiting when i2c bus doesn't exist
v5 :
	updated as per Marc's comments
	better error handling in write
	better default bus handling in read & write
v4 :
	updated as per Sascha and Marc's comments
	use bus 0 as a default for i2c_read & write
	replace malloc with xmalloc
	fix simple_strtol configuration for parameters
v3 : 
	enable brain and fix v2
	tested on iMX27
v2 :
	updated as per Sascha's comments

 commands/Kconfig  |    8 ++
 commands/Makefile |    1 +
 commands/i2c.c    |  214 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 223 insertions(+), 0 deletions(-)
 create mode 100644 commands/i2c.c

diff --git a/commands/Kconfig b/commands/Kconfig
index 0c09f91..0ea32d9 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 74b0994..3eef5de 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 0000000..d38e779
--- /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
-- 
1.6.3.3


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