[U-Boot] [PATCH 17/25] dm: i2c: Add a command to adjust the offset length

Simon Glass
2015-08-11T14:48:09Z

I2C chips can support a register offset, with registers accessible by
sending this offset as the first part of any read or write transaction.
Most I2C chips have a single byte offset, thus the offset length is 1.
This provides access for up 256 registers.

However other offset lengths are supported, including 0.

Add a command to provide access to the offset length from the command
line. This allows the offset length to be read or written.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

common/cmd_i2c.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)

diff --git a/common/cmd_i2c.c b/common/cmd_i2c.c
index 1bc0db8..864b259 100644
--- a/common/cmd_i2c.c
+++ b/common/cmd_i2c.c
@@ -453,6 +453,37 @@ static int do_i2c_flags(cmd_tbl_t *cmdtp, int flag, int argc,

return 0;
}
+
+static int do_i2c_olen(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+ struct udevice *dev;
+ uint olen;
+ int chip;
+ int ret;
+
+ if (argc < 2)
+ return CMD_RET_USAGE;
+
+ chip = simple_strtoul(argv[1], NULL, 16);
+ ret = i2c_get_cur_bus_chip(chip, &dev);
+ if (ret)
+ return i2c_report_err(ret, I2C_ERR_READ);
+
+ if (argc > 2) {
+ olen = simple_strtoul(argv[2], NULL, 16);
+ ret = i2c_set_chip_offset_len(dev, olen);
+ } else {
+ ret = i2c_get_chip_offset_len(dev);
+ if (ret >= 0) {
+ printf("%x\n", ret);
+ ret = 0;
+ }
+ }
+ if (ret)
+ return i2c_report_err(ret, I2C_ERR_READ);
+
+ return 0;
+}
#endif

/**
@@ -1903,6 +1934,7 @@ static cmd_tbl_t cmd_i2c_sub[] = {
U_BOOT_CMD_MKENT(write, 6, 0, do_i2c_write, "", ""),
#ifdef CONFIG_DM_I2C
U_BOOT_CMD_MKENT(flags, 2, 1, do_i2c_flags, "", ""),
+ U_BOOT_CMD_MKENT(olen, 2, 1, do_i2c_olen, "", ""),
#endif
U_BOOT_CMD_MKENT(reset, 0, 1, do_i2c_reset, "", ""),
#if defined(CONFIG_CMD_SDRAM)
@@ -1971,6 +2003,7 @@ static char i2c_help_text[] =
" to I2C; the -s option selects bulk write in a single transaction\n"
#ifdef CONFIG_DM_I2C
"i2c flags chip [flags] - set or get chip flags\n"
+ "i2c olen chip [offset_length] - set or get chip offset length\n"
#endif
"i2c reset - re-init the I2C Controller\n"
#if defined(CONFIG_CMD_SDRAM)
--
2.5.0.rc2.392.g76e840b