[RFC][PATCHv2] new applets: i2c-tools
Bartosz Golaszewski
bartekgola at gmail.com
Thu Dec 11 15:36:20 UTC 2014
This version includes fixes suggested for v1 and implements i2cset. Any
testing and suggestions for size reduction are welcome.
Next: i2cdump and i2cdetect.
v1:
http://lists.busybox.net/pipermail/busybox/2014-December/082071.html
Signed-off-by: Bartosz Golaszewski <bartekgola at gmail.com>
---
miscutils/i2c_tools.c | 727 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 727 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..ad04e0d
--- /dev/null
+++ b/miscutils/i2c_tools.c
@@ -0,0 +1,727 @@
+/* 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:
+
+//applet:IF_I2CGET(APPLET(i2cget, BB_DIR_USR_SBIN, BB_SUID_DROP))
+//applet:IF_I2CSET(APPLET(i2cset, BB_DIR_USR_SBIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_I2CGET) += i2c_tools.o
+//kbuild:lib-$(CONFIG_I2CSET) += 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:
+
+#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
+
+/* 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 pointer.
+ */
+#define INT_TO_PTR(i) ((void*)((long)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;
+ int i;
+
+ if (length > I2C_SMBUS_BLOCK_MAX)
+ length = I2C_SMBUS_BLOCK_MAX;
+ for (i = 1; i <= length; i++)
+ data.block[i] = values[i-1];
+ 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;
+ int i;
+
+ if (length > I2C_SMBUS_BLOCK_MAX)
+ length = I2C_SMBUS_BLOCK_MAX;
+ for (i = 1; i <= length; i++)
+ data.block[i] = values[i-1];
+ data.block[0] = length;
+
+ return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
+ I2C_SMBUS_I2C_BLOCK_BROKEN, &data);
+}
+#endif /* ENABLE_I2CSET */
+
+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)
+{
+ return xstrtoi_range(addr_str, 16, 0x03, 0x77);
+}
+
+static int i2c_parse_data_addr(const char *data_addr)
+{
+ return xstrtoi_range(data_addr, 16, 0, 0xff);
+}
+
+/* Opens the device file associated with given i2c bus. */
+static int i2c_dev_open(int i2cbus)
+{
+ char filename[32];
+ int fd;
+
+ snprintf(filename, sizeof(filename), "/dev/i2c-%d", i2cbus);
+ fd = open_or_warn(filename, O_RDWR);
+ if (fd < 0 && errno == ENOENT) {
+ snprintf(filename, sizeof(filename), "/dev/i2c/%d", i2cbus);
+ fd = xopen(filename, O_RDWR);
+ }
+
+ 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,
+ INT_TO_PTR(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,
+ INT_TO_PTR(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
+static void i2cget_check_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;
+ }
+ check_funcs_test_end(funcs, pec, err);
+}
+#endif /* ENABLE_I2CGET */
+
+#if ENABLE_I2CSET
+static void i2cset_check_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 */
+
+/*********************************** XXXX ***********************************/
+/*
+ * XXX read_line() exists already in util-linux/fdisk.c - move it to
+ * libbb and reuse here in the final version of the patch. This will save
+ * additional 116 bytes.
+ */
+static char *line_ptr;
+static char line_buffer[128];
+
+static int read_line(const char *prompt)
+{
+ int sz;
+
+ sz = read_line_input(NULL, prompt, line_buffer,
+ sizeof(line_buffer), /*timeout*/ -1);
+ if (sz <= 0)
+ exit(EXIT_SUCCESS); /* Ctrl-D or Ctrl-C */
+
+ if (line_buffer[sz-1] == '\n')
+ line_buffer[--sz] = '\0';
+
+ line_ptr = line_buffer;
+ while (*line_ptr != '\0' && (unsigned char)*line_ptr <= ' ')
+ line_ptr++;
+ return *line_ptr;
+}
+
+static void user_confirm(void)
+{
+ if (tolower(read_line("Continue? [y/N] ")) != 'y') {
+ fprintf(stderr, "Aborting.\n");
+ xfunc_die();
+ }
+}
+/*********************************** XXXX ***********************************/
+
+/*
+ * 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");
+
+ user_confirm();
+}
+
+#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);
+ i2cget_check_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) {
+ switch (argv[argc-1][0]) {
+ case 'c': mode = I2C_SMBUS_BYTE; 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);
+ i2cset_check_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);
+
+ user_confirm();
+ }
+ }
+
+ 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 */
--
2.1.3
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