From: Antony Pavlov <antonynpavlov@gmail.com>
To: barebox@lists.infradead.org
Subject: [RFC] commands: i2c_write: enable raw write to address
Date: Thu, 8 Feb 2018 10:48:56 +0300 [thread overview]
Message-ID: <20180208074856.3701-1-antonynpavlov@gmail.com> (raw)
Sometimes for communication with a simple I2C devices
(e.g. PCF8574 or TM1650) it's necessary to send only
one data byte into the I2C device.
Current i2c_write command makes this impossible because
you can't just pass 'device address' and 'register number'
(or 'device address' and 'one data byte') to the command.
You always have to pass all three parameters:
'device address', 'register number' and 'data'.
This commit fixes the problem.
Sample usage:
barebox@barebox sandbox:/ i2c_write -a 0x24 0x01
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
---
commands/i2c.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/commands/i2c.c b/commands/i2c.c
index b74c53509f..21c39fe5af 100644
--- a/commands/i2c.c
+++ b/commands/i2c.c
@@ -115,7 +115,7 @@ static int do_i2c_write(int argc, char *argv[])
count = argc - optind;
- if ((addr < 0) || (reg < 0) || (count == 0) || (addr > 0x7F))
+ if ((addr < 0) || (count == 0) || (addr > 0x7F))
return COMMAND_ERROR_USAGE;
adapter = i2c_get_adapter(bus);
@@ -131,7 +131,11 @@ static int do_i2c_write(int argc, char *argv[])
for (i = 0; i < count; i++)
*(buf + i) = (char) simple_strtol(argv[optind+i], NULL, 0);
- ret = i2c_write_reg(&client, reg | wide, buf, count);
+ if (reg > 0) {
+ ret = i2c_write_reg(&client, reg | wide, buf, count);
+ } else {
+ ret = i2c_master_send(&client, buf, count);
+ }
if (ret != count) {
if (verbose)
printf("write aborted, count(%i) != writestatus(%i)\n",
--
2.15.1
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next reply other threads:[~2018-02-08 7:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-08 7:48 Antony Pavlov [this message]
2018-02-09 8:36 ` Sascha Hauer
2018-02-09 11:22 ` Antony Pavlov
2018-02-13 8:19 ` Sascha Hauer
2018-02-14 6:19 ` Antony Pavlov
2018-02-16 7:53 ` Sascha Hauer
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