[RFC][PATCH v3 2/2] new applets: i2c-tools

Bartosz Golaszewski bartekgola at gmail.com
Tue Dec 16 10:21:45 UTC 2014


This version implements i2cdump. The only program left before the real patch
is i2cdetect.

Signed-off-by: Bartosz Golaszewski <bartekgola at gmail.com>
---
 miscutils/i2c_tools.c | 1052 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 1052 insertions(+)
 create mode 100644 miscutils/i2c_tools.c

diff --git a/miscutils/i2c_tools.c b/miscutils/i2c_tools.c
new file mode 100644
index 0000000..1dbb29c
--- /dev/null
+++ b/miscutils/i2c_tools.c
@@ -0,0 +1,1052 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Minimal i2c-tools implementation for busybox.
+ * Parts of code ported from i2c-tools:
+ * 		http://www.lm-sensors.org/wiki/I2CTools.
+ *
+ * Copyright (C) 2014 by Bartosz Golaszewski <bartekgola at gmail.com>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+//config:config I2CGET
+//config:	bool "i2cget"
+//config:	default y
+//config:	select PLATFORM_LINUX
+//config:	help
+//config:	  Read from I2C/SMBus chip registers.
+//config:
+//config:config I2CSET
+//config:	bool "i2cset"
+//config:	default y
+//config:	select PLATFORM_LINUX
+//config:	help
+//config:	  Set I2C registers.
+//config:
+//config:config I2CDUMP
+//config:	bool "i2cdump"
+//config:	default y
+//config:	select PLATFORM_LINUX
+//config:	help
+//config:	  Examine I2C registers.
+//config:
+
+//applet:IF_I2CGET(APPLET(i2cget, BB_DIR_USR_SBIN, BB_SUID_DROP))
+//applet:IF_I2CSET(APPLET(i2cset, BB_DIR_USR_SBIN, BB_SUID_DROP))
+//applet:IF_I2CDUMP(APPLET(i2cdump, BB_DIR_USR_SBIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_I2CGET) += i2c_tools.o
+//kbuild:lib-$(CONFIG_I2CSET) += i2c_tools.o
+//kbuild:lib-$(CONFIG_I2CDUMP) += i2c_tools.o
+
+//usage:#define i2cget_trivial_usage
+//usage:       "[-f] [-y] BUS CHIP-ADDRESS [DATA-ADDRESS [MODE]]"
+//usage:#define i2cget_full_usage "\n\n"
+//usage:       "Read from I2C/SMBus chip registers\n"
+//usage:     "\n  I2CBUS is an i2c bus number"
+//usage:     "\n  ADDRESS is an integer (0x03 - 0x77)"
+//usage:     "\n  MODE is one of:"
+//usage:     "\n    b (read byte data, default)"
+//usage:     "\n    w (read word data)"
+//usage:     "\n    c (write byte/read byte)"
+//usage:   "\n\n  Append p for SMBus PEC"
+//usage:   "\n\n  -f - force access to device"
+//usage:     "\n  -y - disable interactive mode"
+//usage:
+//usage:#define i2cset_trivial_usage
+//usage:       "[-f] [-y] [-m MASK] BUS CHIP-ADDR DATA-ADDR [VALUE] ... [MODE]"
+//usage:#define i2cset_full_usage "\n\n"
+//usage:       "Set I2C registers\n"
+//usage:     "\n  I2CBUS is an i2c bus number"
+//usage:     "\n  ADDRESS is an integer (0x03 - 0x77)"
+//usage:     "\n  MODE is one of:"
+//usage:     "\n    c (byte, no value)"
+//usage:     "\n    b (byte data, default)"
+//usage:     "\n    w (word data)"
+//usage:     "\n    i (I2C block data)"
+//usage:     "\n    s (SMBus block data)"
+//usage:   "\n\n  Append p for SMBus PEC"
+//usage:   "\n\n  -f - force access to device"
+//usage:     "\n  -y - disable interactive mode"
+//usage:     "\n  -r - read back and compare the result"
+//usage:     "\n  -m - mask specifying which bits to write"
+//usage:
+//usage:#define i2cdump_trivial_usage
+//usage:       "[-f] [-r FIRST-LAST] [-y] BUS ADDR [MODE]"
+//usage:#define i2cdump_full_usage "\n\n"
+//usage:       "Examine I2C registers\n"
+//usage:     "\n  I2CBUS is an i2c bus number"
+//usage:     "\n  ADDRESS is an integer (0x03 - 0x77)"
+//usage:     "\n  MODE is one of:"
+//usage:     "\n    b (byte, default)"
+//usage:     "\n    w (word)"
+//usage:     "\n    W (word on even register addresses)"
+//usage:     "\n    i (I2C block)"
+//usage:     "\n    s (SMBus block)"
+//usage:     "\n    c (consecutive byte)"
+//usage:   "\n\n  Append p for SMBus PEC"
+//usage:   "\n\n  -f - force access to device"
+//usage:     "\n  -y - disable interactive mode"
+//usage:     "\n  -r - limit the number of registers being accessed"
+//usage:
+
+/*
+ * Unsupported stuff:
+ *
+ * - upstream i2c-tools can also look-up i2c busses by name, we only accept
+ *   numbers,
+ * - bank and bankreg parameters for i2cdump are not supported because of
+ *   their limited usefulness (see i2cdump manual entry for more info),
+ *   although this is a potential TODO.
+ */
+
+#include "libbb.h"
+
+/*
+ * /dev/i2c-X ioctl commands. The ioctl's parameter is always an unsigned long,
+ * except for:
+ *    - I2C_FUNCS, takes pointer to an unsigned long
+ *    - I2C_RDWR, takes pointer to struct i2c_rdwr_ioctl_data
+ *    - I2C_SMBUS, takes pointer to struct i2c_smbus_ioctl_data
+ */
+
+/* Number of times a device address should be polled when not acknowledging */
+#define I2C_RETRIES	0x0701
+/* Set timeout in units of 10 ms */
+#define I2C_TIMEOUT	0x0702
+
+/*
+ * NOTE: Slave address is 7 or 10 bits, but 10-bit addresses
+ * are NOT supported! (due to code brokenness)
+ */
+
+/* Use this slave address */
+#define I2C_SLAVE	0x0703
+/* Use this slave address, even if it is already in use by a driver! */
+#define I2C_SLAVE_FORCE	0x0706
+/* 0 for 7 bit addrs, != 0 for 10 bit */
+#define I2C_TENBIT	0x0704
+/* Get the adapter functionality mask */
+#define I2C_FUNCS	0x0705
+/* Combined R/W transfer (one STOP only) */
+#define I2C_RDWR	0x0707
+/* != 0 to use PEC with SMBus */
+#define I2C_PEC		0x0708
+/* SMBus transfer */
+#define I2C_SMBUS	0x0720
+
+/* This is the structure as used in the I2C_SMBUS ioctl call */
+struct i2c_smbus_ioctl_data {
+	uint8_t read_write;
+	uint8_t command;
+	uint32_t size;
+	union i2c_smbus_data *data;
+};
+
+/* This is the structure as used in the I2C_RDWR ioctl call */
+struct i2c_rdwr_ioctl_data {
+	struct i2c_msg *msgs;	/* pointers to i2c_msgs */
+	uint32_t nmsgs;			/* number of i2c_msgs */
+};
+
+/* As specified in SMBus standard */
+#define I2C_SMBUS_BLOCK_MAX		32
+/* Not specified but we use same structure */
+#define I2C_SMBUS_I2C_BLOCK_MAX		32
+
+/*
+ * Data for SMBus Messages
+ */
+union i2c_smbus_data {
+	uint8_t byte;
+	uint16_t word;
+	/* block[0] is used for length and one more for PEC */
+	uint8_t block[I2C_SMBUS_BLOCK_MAX + 2];
+};
+
+#define  I2C_RDRW_IOCTL_MAX_MSGS	42
+
+#define I2C_MAX_REGS			256
+
+/* smbus_access read or write markers */
+#define I2C_SMBUS_READ	1
+#define I2C_SMBUS_WRITE	0
+
+/* SMBus transaction types (size parameter in the below functions). */
+#define I2C_SMBUS_QUICK			0
+#define I2C_SMBUS_BYTE			1
+#define I2C_SMBUS_BYTE_DATA		2
+#define I2C_SMBUS_WORD_DATA		3
+#define I2C_SMBUS_PROC_CALL		4
+#define I2C_SMBUS_BLOCK_DATA		5
+#define I2C_SMBUS_I2C_BLOCK_BROKEN	6
+#define I2C_SMBUS_BLOCK_PROC_CALL	7
+#define I2C_SMBUS_I2C_BLOCK_DATA	8
+
+/* Defines to determine what functionality is present */
+#define I2C_FUNC_I2C				0x00000001
+#define I2C_FUNC_10BIT_ADDR			0x00000002
+#define I2C_FUNC_PROTOCOL_MANGLING		0x00000004
+#define I2C_FUNC_SMBUS_PEC			0x00000008
+#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL		0x00008000
+#define I2C_FUNC_SMBUS_QUICK			0x00010000
+#define I2C_FUNC_SMBUS_READ_BYTE		0x00020000
+#define I2C_FUNC_SMBUS_WRITE_BYTE		0x00040000
+#define I2C_FUNC_SMBUS_READ_BYTE_DATA		0x00080000
+#define I2C_FUNC_SMBUS_WRITE_BYTE_DATA		0x00100000
+#define I2C_FUNC_SMBUS_READ_WORD_DATA		0x00200000
+#define I2C_FUNC_SMBUS_WRITE_WORD_DATA		0x00400000
+#define I2C_FUNC_SMBUS_PROC_CALL		0x00800000
+#define I2C_FUNC_SMBUS_READ_BLOCK_DATA		0x01000000
+#define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 	0x02000000
+#define I2C_FUNC_SMBUS_READ_I2C_BLOCK		0x04000000
+#define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK		0x08000000
+
+/*
+ * This is needed for ioctl_or_perror_and_die() since it only accepts pointers.
+ */
+static void *itoptr(int i)
+{
+	return (void*)(intptr_t)i;
+}
+
+static int32_t i2c_smbus_access(int fd, char read_write, uint8_t cmd,
+				int size, union i2c_smbus_data *data)
+{
+	struct i2c_smbus_ioctl_data args;
+
+	args.read_write = read_write;
+	args.command = cmd;
+	args.size = size;
+	args.data = data;
+
+	return ioctl(fd, I2C_SMBUS, &args);
+}
+
+static int32_t i2c_smbus_read_byte(int fd)
+{
+	union i2c_smbus_data data;
+	int err;
+
+	err = i2c_smbus_access(fd, I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &data);
+	if (err < 0)
+		return err;
+
+	return 0xff & data.byte;
+}
+
+static int32_t i2c_smbus_write_byte(int fd, uint8_t val)
+{
+	return i2c_smbus_access(fd, I2C_SMBUS_WRITE,
+				val, I2C_SMBUS_BYTE, NULL);
+}
+
+static int32_t i2c_smbus_read_byte_data(int fd, uint8_t cmd)
+{
+	union i2c_smbus_data data;
+	int err;
+
+	err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
+			       I2C_SMBUS_BYTE_DATA, &data);
+	if (err < 0)
+		return err;
+
+	return 0xff & data.byte;
+}
+
+static int32_t i2c_smbus_read_word_data(int fd, uint8_t cmd)
+{
+	union i2c_smbus_data data;
+	int err;
+
+	err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
+			       I2C_SMBUS_WORD_DATA, &data);
+	if (err < 0)
+		return err;
+
+	return 0xffff & data.word;
+}
+
+#if ENABLE_I2CSET
+static int32_t i2c_smbus_write_byte_data(int file,
+					 uint8_t cmd, uint8_t value)
+{
+	union i2c_smbus_data data;
+
+	data.byte = value;
+
+	return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
+				I2C_SMBUS_BYTE_DATA, &data);
+}
+
+static int32_t i2c_smbus_write_word_data(int file, uint8_t cmd, uint16_t value)
+{
+	union i2c_smbus_data data;
+
+	data.word = value;
+
+	return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
+				I2C_SMBUS_WORD_DATA, &data);
+}
+
+static int32_t i2c_smbus_write_block_data(int file, uint8_t cmd,
+				   uint8_t length, const uint8_t *values)
+{
+	union i2c_smbus_data data;
+
+	if (length > I2C_SMBUS_BLOCK_MAX)
+		length = I2C_SMBUS_BLOCK_MAX;
+
+	memcpy(data.block+1, values, length);
+	data.block[0] = length;
+
+	return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
+				I2C_SMBUS_BLOCK_DATA, &data);
+}
+
+static int32_t i2c_smbus_write_i2c_block_data(int file, uint8_t cmd,
+				       uint8_t length, const uint8_t *values)
+{
+	union i2c_smbus_data data;
+
+	if (length > I2C_SMBUS_BLOCK_MAX)
+		length = I2C_SMBUS_BLOCK_MAX;
+
+	memcpy(data.block+1, values, length);
+	data.block[0] = length;
+
+	return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
+				I2C_SMBUS_I2C_BLOCK_BROKEN, &data);
+}
+#endif /* ENABLE_I2CSET */
+
+#if ENABLE_I2CDUMP
+/*
+ * Returns the number of bytes read, vals must hold at
+ * least I2C_SMBUS_BLOCK_MAX bytes.
+ */
+static int32_t i2c_smbus_read_block_data(int fd, uint8_t cmd, uint8_t *vals)
+{
+	union i2c_smbus_data data;
+	int i, err;
+
+	err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
+			       I2C_SMBUS_BLOCK_DATA, &data);
+	if (err < 0)
+		return err;
+
+	for (i = 1; i <= data.block[0]; i++)
+		vals[i-1] = data.block[i];
+	return data.block[0];
+}
+
+static int32_t i2c_smbus_read_i2c_block_data(int fd, uint8_t cmd,
+					     uint8_t len, uint8_t *vals)
+{
+	union i2c_smbus_data data;
+	int i, err;
+
+	if (len > I2C_SMBUS_BLOCK_MAX)
+		len = I2C_SMBUS_BLOCK_MAX;
+	data.block[0] = len;
+
+	err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
+			       len == 32 ? I2C_SMBUS_I2C_BLOCK_BROKEN :
+					   I2C_SMBUS_I2C_BLOCK_DATA, &data);
+	if (err < 0)
+		return err;
+
+	for (i = 1; i <= data.block[0]; i++)
+		vals[i-1] = data.block[i];
+	return data.block[0];
+}
+#endif /* ENABLE_I2CDUMP */
+
+static int i2c_bus_lookup(const char *bus_str)
+{
+	return xstrtoi_range(bus_str, 10, 0, 0xfffff);
+}
+
+static int i2c_parse_bus_addr(const char *addr_str)
+{
+	/* Slave address must be in range 0x03 - 0x77. */
+	return xstrtoi_range(addr_str, 16, 0x03, 0x77);
+}
+
+#if ENABLE_I2CGET || ENABLE_I2CSET
+static int i2c_parse_data_addr(const char *data_addr)
+{
+	/* Data address must be an 8 bit integer. */
+	return xstrtoi_range(data_addr, 16, 0, 0xff);
+}
+#endif /* ENABLE_I2CGET || ENABLE_I2CSET */
+
+/*
+ * Opens the device file associated with given i2c bus.
+ *
+ * Upstream i2c-tools also support opening devices by i2c bus name
+ * but we drop it here for size reduction.
+ */
+static int i2c_dev_open(int i2cbus)
+{
+	char filename[32];
+	int fd;
+
+	snprintf(filename, sizeof(filename), "/dev/i2c-%d", i2cbus);
+	fd = open(filename, O_RDWR);
+	if (fd < 0 && errno == ENOENT) {
+		snprintf(filename, sizeof(filename), "/dev/i2c/%d", i2cbus);
+		fd = open(filename, O_RDWR);
+	}
+
+	if (fd < 0)
+		bb_perror_msg_and_die(
+			"Could not open /dev/i2c-%d or /dev/i2c/%d",
+			i2cbus, i2cbus);
+
+	return fd;
+}
+
+static void i2c_set_slave_addr(int fd, int addr, int force)
+{
+	ioctl_or_perror_and_die(fd, force ? I2C_SLAVE_FORCE : I2C_SLAVE,
+				itoptr(addr),
+				"Could not set address to 0x%02x", addr);
+}
+
+static void i2c_set_pec(int fd, int pec)
+{
+	ioctl_or_perror_and_die(fd, I2C_PEC,
+				itoptr(pec ? 1 : 0),
+				"Could not set PEC");
+}
+
+/* Size reducing helpers for xxx_check_funcs(). */
+static void get_funcs_matrix(int fd, unsigned long *funcs)
+{
+	ioctl_or_perror_and_die(fd, I2C_FUNCS, funcs,
+			"Could not get the adapter functionality matrix");
+}
+
+static void check_funcs_test_end(int funcs, int pec, const char *err)
+{
+	if (pec && !(funcs & (I2C_FUNC_SMBUS_PEC | I2C_FUNC_I2C)))
+		fprintf(stderr,
+			"Warning: Adapter does not seem to support PEC\n");
+
+	if (err)
+		bb_error_msg_and_die("Adapter does not have %s capability",
+				     err);
+}
+
+/*
+ * The below functions emit an error message and exit if the adapter doesn't
+ * support desired functionalities.
+ */
+#if ENABLE_I2CGET || ENABLE_I2CDUMP
+static void check_read_funcs(int fd, int mode, int data_addr, int pec)
+{
+	unsigned long funcs;
+	const char *err = NULL;
+
+	get_funcs_matrix(fd, &funcs);
+	switch (mode) {
+	case I2C_SMBUS_BYTE:
+		if (!(funcs & I2C_FUNC_SMBUS_READ_BYTE)) {
+			err = "SMBus receive byte";
+			break;
+		}
+		if (data_addr >= 0 && !(funcs & I2C_FUNC_SMBUS_WRITE_BYTE))
+			err = "SMBus send byte";
+		break;
+	case I2C_SMBUS_BYTE_DATA:
+		if (!(funcs & I2C_FUNC_SMBUS_READ_BYTE_DATA))
+			err = "SMBus read byte";
+		break;
+	case I2C_SMBUS_WORD_DATA:
+		if (!(funcs & I2C_FUNC_SMBUS_READ_WORD_DATA))
+			err = "SMBus read word";
+		break;
+#if ENABLE_I2CDUMP
+	case I2C_SMBUS_BLOCK_DATA:
+		if (!(funcs & I2C_FUNC_SMBUS_READ_BLOCK_DATA))
+			err = "SMBus block read";
+		break;
+
+	case I2C_SMBUS_I2C_BLOCK_DATA:
+		if (!(funcs & I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+			err = "I2C block read";
+		break;
+#endif /* ENABLE_I2CDUMP */
+	default:
+		bb_error_msg_and_die("Programmer goofed!");
+	}
+	check_funcs_test_end(funcs, pec, err);
+}
+#endif /* ENABLE_I2CGET || ENABLE_I2CDUMP */
+
+#if ENABLE_I2CSET
+static void check_write_funcs(int fd, int mode, int pec)
+{
+	unsigned long funcs;
+	const char *err = NULL;
+
+	get_funcs_matrix(fd, &funcs);
+	switch (mode) {
+	case I2C_SMBUS_BYTE:
+		if (!(funcs & I2C_FUNC_SMBUS_WRITE_BYTE))
+			err = "SMBus send byte";
+		break;
+
+	case I2C_SMBUS_BYTE_DATA:
+		if (!(funcs & I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
+			err = "SMBus write byte";
+		break;
+
+	case I2C_SMBUS_WORD_DATA:
+		if (!(funcs & I2C_FUNC_SMBUS_WRITE_WORD_DATA))
+			err = "SMBus write word";
+		break;
+
+	case I2C_SMBUS_BLOCK_DATA:
+		if (!(funcs & I2C_FUNC_SMBUS_WRITE_BLOCK_DATA))
+			err = "SMBus block write";
+		break;
+	case I2C_SMBUS_I2C_BLOCK_DATA:
+		if (!(funcs & I2C_FUNC_SMBUS_WRITE_I2C_BLOCK))
+			err = "I2C block write";
+		break;
+	}
+	check_funcs_test_end(funcs, pec, err);
+}
+#endif /* ENABLE_I2CSET */
+
+static void confirm_or_abort(void)
+{
+	if (!user_confirm("Continue?"))
+		bb_error_msg_and_die("Aborting");
+}
+
+/*
+ * Return only if user confirms the action, abort otherwise.
+ *
+ * The messages displayed here are much less elaborate than their i2c-tools
+ * counterparts - this is done for size reduction.
+ */
+static void confirm_action(int bus_addr, int mode, int data_addr, int pec)
+{
+	fprintf(stderr, "WARNING! This program can confuse your I2C bus\n");
+
+	/* Don't let the user break his/her EEPROMs */
+	if (bus_addr >= 0x50 && bus_addr <= 0x57 && pec) {
+		fprintf(stderr, "This is I2C not smbus - using PEC on I2C "
+			"devices may result in data loss. Aborting.\n");
+		xfunc_die();
+	}
+
+	if (mode == I2C_SMBUS_BYTE && data_addr >= 0 && pec)
+		fprintf(stderr, "WARNING! May interpret a write byte command "
+			"with PEC as a write byte data command!\n");
+
+	if (pec)
+		fprintf(stderr, "PEC checking enabled.\n");
+
+	confirm_or_abort();
+}
+
+#if ENABLE_I2CGET
+int i2cget_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int i2cget_main(int argc, char **argv)
+{
+	static const unsigned opt_f = (1 << 0), opt_y = (1 << 1);
+	static const char *const optstr = "fy";
+
+	int bus_num, bus_addr, data_addr = -1, status;
+	int mode = I2C_SMBUS_BYTE, pec = 0, fd;
+	unsigned opts;
+
+	opts = getopt32(argv, optstr);
+	argv += optind;
+	argc -= optind;
+
+	if (argc < 2)
+		bb_show_usage();
+
+	bus_num = i2c_bus_lookup(argv[0]);
+	bus_addr = i2c_parse_bus_addr(argv[1]);
+
+	if (argc > 2) {
+		data_addr = i2c_parse_data_addr(argv[2]);
+		mode = I2C_SMBUS_BYTE_DATA;
+	}
+
+	if (argc > 3) {
+		switch (argv[3][0]) {
+		case 'b':	/* Already set */		break;
+		case 'w':	mode = I2C_SMBUS_WORD_DATA;	break;
+		case 'c':	mode = I2C_SMBUS_BYTE;		break;
+		default:
+			bb_error_msg("Invalid mode");
+			bb_show_usage();
+		}
+		pec = argv[3][1] == 'p';
+	}
+
+	fd = i2c_dev_open(bus_num);
+	check_read_funcs(fd, mode, data_addr, pec);
+	i2c_set_slave_addr(fd, bus_addr, opts & opt_f);
+
+	if (!(opts & opt_y))
+		confirm_action(bus_addr, mode, data_addr, pec);
+
+	if (pec)
+		i2c_set_pec(fd, 1);
+
+	switch (mode) {
+	case I2C_SMBUS_BYTE:
+		if (data_addr >= 0) {
+			status = i2c_smbus_write_byte(fd, data_addr);
+			if (status < 0)
+				fprintf(stderr, "Warning - write failed\n");
+		}
+		status = i2c_smbus_read_byte(fd);
+		break;
+	case I2C_SMBUS_WORD_DATA:
+		status = i2c_smbus_read_word_data(fd, data_addr);
+		break;
+	default: /* I2C_SMBUS_BYTE_DATA */
+		status = i2c_smbus_read_byte_data(fd, data_addr);
+	}
+	close(fd);
+
+	if (status < 0)
+		bb_perror_msg_and_die("Read failed");
+
+	printf("0x%0*x\n", mode == I2C_SMBUS_WORD_DATA ? 4 : 2, status);
+
+	return 0;
+}
+#endif /* ENABLE_I2CGET */
+
+#if ENABLE_I2CSET
+int i2cset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int i2cset_main(int argc, char **argv)
+{
+	static const unsigned opt_f = (1 << 0), opt_y = (1 << 1),
+			      opt_m = (1 << 2), opt_r = (1 << 3);
+	static const char *const optstr = "fym:r";
+
+	int bus_num, bus_addr, data_addr, mode = I2C_SMBUS_BYTE, pec = 0;
+	int val, blen = 0, mask = 0, fd, status;
+	unsigned char block[I2C_SMBUS_BLOCK_MAX];
+	char *opt_m_arg = NULL;
+	unsigned opts;
+
+	opts = getopt32(argv, optstr, &opt_m_arg);
+	argv += optind;
+	argc -= optind;
+
+	if (argc < 3)
+		bb_show_usage();
+
+	bus_num = i2c_bus_lookup(argv[0]);
+	bus_addr = i2c_parse_bus_addr(argv[1]);
+	data_addr = i2c_parse_data_addr(argv[2]);
+
+	if (argc > 3) {
+		if (argc == 4 && argv[3][0] != 'c') {
+			mode = I2C_SMBUS_BYTE_DATA; /* Implicit b */
+		} else {
+			switch (argv[argc-1][0]) {
+			case 'c': /* Already set */			break;
+			case 'b': mode = I2C_SMBUS_BYTE_DATA;		break;
+			case 'w': mode = I2C_SMBUS_WORD_DATA;		break;
+			case 's': mode = I2C_SMBUS_BLOCK_DATA;		break;
+			case 'i': mode = I2C_SMBUS_I2C_BLOCK_DATA;	break;
+			default:
+				bb_error_msg("Invalid mode");
+				bb_show_usage();
+			}
+
+			pec = argv[argc-1][1] == 'p';
+			if (mode == I2C_SMBUS_BLOCK_DATA ||
+					mode == I2C_SMBUS_I2C_BLOCK_DATA) {
+				if (pec && mode == I2C_SMBUS_I2C_BLOCK_DATA)
+					bb_error_msg_and_die(
+						"PEC not supported for I2C "
+						"block writes!");
+				if (opts & opt_m)
+					bb_error_msg_and_die(
+						"Mask not supported for block "
+						"writes!\n");
+			}
+		}
+	}
+
+	/* Prepare the value(s) to be written according to current mode. */
+	switch (mode) {
+	case I2C_SMBUS_BYTE_DATA:
+		val = xstrtoi_range(argv[3], 0, 0, 0xff);
+		break;
+	case I2C_SMBUS_WORD_DATA:
+		val = xstrtoi_range(argv[3], 0, 0, 0xffff);
+		break;
+	case I2C_SMBUS_BLOCK_DATA:
+	case I2C_SMBUS_I2C_BLOCK_DATA:
+		for (blen = 3; blen < (argc - 1); blen++)
+			block[blen] = xstrtoi_range(argv[blen], 0, 0, 0xff);
+		val = -1;
+		break;
+	default:
+		val = -1;
+		break;
+	}
+
+	if (opts & opt_m) {
+		mask = xstrtoi_range(opt_m_arg, 0, 0,
+				(mode == I2C_SMBUS_BYTE ||
+				 mode == I2C_SMBUS_BYTE_DATA) ? 0xff : 0xffff);
+	}
+
+	fd = i2c_dev_open(bus_num);
+	check_write_funcs(fd, mode, pec);
+	i2c_set_slave_addr(fd, bus_addr, opts & opt_f);
+
+	if (!(opts & opt_y))
+		confirm_action(bus_addr, mode, data_addr, pec);
+
+	/*
+	 * If we're using mask - read the current value here and adjust the
+	 * value to be written.
+	 */
+	if (opts & opt_m) {
+		int tmpval;
+
+		switch (mode) {
+		case I2C_SMBUS_BYTE:
+			tmpval = i2c_smbus_read_byte(fd);
+			break;
+		case I2C_SMBUS_WORD_DATA:
+			tmpval = i2c_smbus_read_word_data(fd, data_addr);
+			break;
+		default:
+			tmpval = i2c_smbus_read_byte_data(fd, data_addr);
+		}
+
+		if (tmpval < 0)
+			bb_perror_msg_and_die("Failed to read old value");
+
+		val = (val & mask) | (tmpval & ~mask);
+
+		if (!(opts & opt_y)) {
+			fprintf(stderr, "Old value 0x%0*x, write mask "
+				"0x%0*x: Will write 0x%0*x to register "
+				"0x%02x\n",
+				mode == I2C_SMBUS_WORD_DATA ? 4 : 2, tmpval,
+				mode == I2C_SMBUS_WORD_DATA ? 4 : 2, mask,
+				mode == I2C_SMBUS_WORD_DATA ? 4 : 2, val,
+				data_addr);
+
+			confirm_or_abort();
+		}
+	}
+
+	if (pec)
+		i2c_set_pec(fd, 1);
+
+	switch (mode) {
+	case I2C_SMBUS_BYTE:
+		status = i2c_smbus_write_byte(fd, data_addr);
+		break;
+	case I2C_SMBUS_WORD_DATA:
+		status = i2c_smbus_write_word_data(fd, data_addr, val);
+		break;
+	case I2C_SMBUS_BLOCK_DATA:
+		status = i2c_smbus_write_block_data(fd, data_addr,
+						    blen, block);
+		break;
+	case I2C_SMBUS_I2C_BLOCK_DATA:
+		status = i2c_smbus_write_i2c_block_data(fd, data_addr,
+							blen, block);
+		break;
+	default: /* I2C_SMBUS_BYTE_DATA */
+		status = i2c_smbus_write_byte_data(fd, data_addr, val);
+		break;
+	}
+	if (status < 0)
+		bb_perror_msg_and_die("Write failed\n");
+
+	if (pec)
+		i2c_set_pec(fd, 0); /* Clear PEC */
+
+	/* No readback required - we're done. */
+	if (!(opts & opt_r))
+		return 0;
+
+	switch (mode) {
+	case I2C_SMBUS_BYTE:
+		status = i2c_smbus_read_byte(fd);
+		val = data_addr;
+		break;
+	case I2C_SMBUS_WORD_DATA:
+		status = i2c_smbus_read_word_data(fd, data_addr);
+		break;
+	default: /* I2C_SMBUS_BYTE_DATA */
+		status = i2c_smbus_read_byte_data(fd, data_addr);
+	}
+
+	if (status < 0) {
+		printf("Warning - readback failed\n");
+	} else
+	if (status != val) {
+		printf("Warning - data mismatch - wrote "
+		       "0x%0*x, read back 0x%0*x\n",
+		       mode == I2C_SMBUS_WORD_DATA ? 4 : 2, val,
+		       mode == I2C_SMBUS_WORD_DATA ? 4 : 2, status);
+	} else {
+		printf("Value 0x%0*x written, readback matched\n",
+		       mode == I2C_SMBUS_WORD_DATA ? 4 : 2, val);
+	}
+
+	return 0;
+}
+#endif /* ENABLE_I2CSET */
+
+#if ENABLE_I2CDUMP
+int i2cdump_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int i2cdump_main(int argc, char **argv)
+{
+	static const unsigned opt_f = (1 << 0), opt_y = (1 << 1),
+			      opt_r = (1 << 2);
+	static const char *const optstr = "fyr:";
+
+	int bus_num, bus_addr, mode = I2C_SMBUS_BYTE_DATA, even = 0, pec = 0;
+	int first = 0x00, last = 0xff, fd, i, j, res, blen = 0, tmp;
+	unsigned char cblock[I2C_SMBUS_BLOCK_MAX + I2C_MAX_REGS];
+	unsigned char block[I2C_SMBUS_BLOCK_MAX];
+	char *opt_r_str, *dash;
+	unsigned opts;
+
+	opts = getopt32(argv, optstr, &opt_r_str);
+	argv += optind;
+	argc -= optind;
+
+	if (argc < 2)
+		bb_show_usage();
+
+	bus_num = i2c_bus_lookup(argv[0]);
+	bus_addr = i2c_parse_bus_addr(argv[1]);
+
+	if (argc > 2) {
+		switch (argv[2][0]) {
+		case 'b': /* Already set */			break;
+		case 'c': mode = I2C_SMBUS_BYTE;		break;
+		case 'w': mode = I2C_SMBUS_WORD_DATA;		break;
+		case 'W':
+			mode = I2C_SMBUS_WORD_DATA;
+			even = 1;
+			break;
+		case 's': mode = I2C_SMBUS_BLOCK_DATA;		break;
+		case 'i': mode = I2C_SMBUS_I2C_BLOCK_DATA;	break;
+		default:
+			bb_error_msg_and_die("Invalid mode");
+		}
+
+		if (argv[2][1] == 'p') {
+			if (argv[2][0] == 'W' || argv[2][0] == 'i') {
+				bb_error_msg_and_die(
+					"pec not supported for -W and -i");
+			} else {
+				pec = 1;
+			}
+		}
+	}
+
+	if (opts & opt_r) {
+		first = strtol(opt_r_str, &dash, 0);
+		if (dash == opt_r_str || *dash != '-' ||
+		    first < 0 || first > 0xff)
+			bb_error_msg_and_die("Invalid range");
+		last = xstrtoi_range(++dash, 0, first, 0xff);
+
+		/* Range is not available for every mode */
+		switch (mode) {
+		case I2C_SMBUS_BYTE:
+		case I2C_SMBUS_BYTE_DATA:
+			break;
+		case I2C_SMBUS_WORD_DATA:
+			if (!even || (!(first % 2) && last % 2))
+				break;
+			/* Fall through */
+		default:
+			bb_error_msg_and_die(
+				"Range not compatible with selected mode!");
+		}
+	}
+
+	fd = i2c_dev_open(bus_num);
+	check_read_funcs(fd, mode, -1 /* data_addr */, pec);
+	i2c_set_slave_addr(fd, bus_addr, opts & opt_f);
+
+	if (pec)
+		i2c_set_pec(fd, 1);
+
+	if (!(opts & opt_y))
+		confirm_action(bus_addr, mode, -1 /* data_addr */, pec);
+
+	/* All but word data */
+	if (mode != I2C_SMBUS_WORD_DATA || even) {
+		/*
+		 * FIXME This section has been ported from upstream i2cdump.
+		 * It has been reworked a bit but is still pretty spaghetti
+		 * and needs splitting into several functions.
+		 */
+		if (mode == I2C_SMBUS_BLOCK_DATA ||
+		    mode == I2C_SMBUS_I2C_BLOCK_DATA) {
+			res = i2c_smbus_read_block_data(fd, 0, cblock);
+			blen = res;
+		} else {
+			for (res = 0; res < I2C_MAX_REGS; res += tmp) {
+				tmp = i2c_smbus_read_i2c_block_data(
+					fd, res, I2C_SMBUS_BLOCK_MAX,
+					cblock + res);
+				if (tmp < 0) {
+					bb_error_msg_and_die(
+						"Block read failed");
+				}
+			}
+			if (res >= I2C_MAX_REGS)
+				res = I2C_MAX_REGS;
+			for (i = 0; i < res; i++)
+				block[i] = cblock[i];
+			if (mode != I2C_SMBUS_BLOCK_DATA)
+				for (i = res; i < I2C_MAX_REGS; i++)
+					cblock[i] = -1;
+		}
+
+		if (mode == I2C_SMBUS_BYTE) {
+			res = i2c_smbus_write_byte(fd, first);
+			if (res < 0)
+				bb_perror_msg_and_die(
+					"Error: Write start address failed");
+		}
+
+		printf("     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f"
+		       "    0123456789abcdef\n");
+
+		for (i = 0; i < I2C_MAX_REGS; i += 0x10) {
+			if (mode == I2C_SMBUS_BLOCK_DATA && i >= blen)
+				break;
+			if (i/16 < first/16)
+				continue;
+			if (i/16 > last/16)
+				break;
+
+			printf("%02x: ", i);
+			for (j = 0; j < 16; j++) {
+				fflush(stdout);
+				/* Skip unwanted registers */
+				if (i+j < first || i+j > last) {
+					printf("   ");
+					if (mode == I2C_SMBUS_WORD_DATA) {
+						printf("   ");
+						j++;
+					}
+					continue;
+				}
+
+				switch (mode) {
+				case I2C_SMBUS_BYTE_DATA:
+					res = i2c_smbus_read_byte_data(fd, i+j);
+					block[i+j] = res;
+					break;
+				case I2C_SMBUS_WORD_DATA:
+					res = i2c_smbus_read_word_data(fd, i+j);
+					if (res < 0) {
+						block[i+j] = res;
+						block[i+j+1] = res;
+					} else {
+						block[i+j] = res & 0xff;
+						block[i+j+1] = res >> 8;
+					}
+					break;
+				case I2C_SMBUS_BYTE:
+					res = i2c_smbus_read_byte(fd);
+					block[i+j] = res;
+					break;
+				default:
+					res = block[i+j];
+				}
+
+				if (mode == I2C_SMBUS_BLOCK_DATA &&
+				    i+j >= blen) {
+					printf("   ");
+				} else if (res < 0) {
+					printf("XX ");
+					if (mode == I2C_SMBUS_WORD_DATA)
+						printf("XX ");
+				} else {
+					printf("%02x ", block[i+j]);
+					if (mode == I2C_SMBUS_WORD_DATA)
+						printf("%02x ", block[i+j+1]);
+				}
+
+				if (mode == I2C_SMBUS_WORD_DATA)
+					j++;
+			}
+			printf("   ");
+
+			for (j = 0; j < 16; j++) {
+				if (mode == I2C_SMBUS_BLOCK_DATA && i+j >= blen)
+					break;
+				/* Skip unwanted registers */
+				if (i+j < first || i+j > last) {
+					printf(" ");
+					continue;
+				}
+
+				res = block[i+j];
+				if (res < 0) {
+					printf("X");
+				} else if ((res & 0xff) == 0x00 ||
+					   (res & 0xff) == 0xff) {
+					printf(".");
+				} else if ((res & 0xff) < 32 ||
+					   (res & 0xff) >= 127) {
+					printf("?");
+				} else {
+					printf("%c", res & 0xff);
+				}
+			}
+			printf("\n");
+		}
+	} else {
+		/* Word data */
+		printf("     0,8  1,9  2,a  3,b  4,c  5,d  6,e  7,f\n");
+		for (i = 0; i < 256; i += 8) {
+			if (i/8 < first/8)
+				continue;
+			if (i/8 > last/8)
+				break;
+
+			printf("%02x: ", i);
+			for (j = 0; j < 8; j++) {
+				/* Skip unwanted registers */
+				if (i+j < first || i+j > last) {
+					printf("     ");
+					continue;
+				}
+
+				res = i2c_smbus_read_word_data(fd, i+j);
+				if (res < 0)
+					printf("XXXX ");
+				else
+					printf("%04x ", res & 0xffff);
+			}
+			printf("\n");
+		}
+	}
+
+	return 0;
+}
+#endif /* ENABLE_I2CDUMP */
-- 
2.1.3



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