From 63f72f0cd0d01ef6138bfba80b7cd19d57c6602c Mon Sep 17 00:00:00 2001
From: Werner Zeh <werner.zeh@siemens.com>
Date: Fri, 26 Aug 2022 13:17:52 +0200
Subject: device/i2c_bus: Add routines to read and write multiple bytes
Some devices require that several bytes are written with a single I2C
write command. Extend the i2c_bus interface functions and add both, read
and write for more than one byte at a defined byte offset.
Change-Id: I0eec2e1d4185170f02b4ab35aa6546dc69569303
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67098
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Mario Scheithauer <mario.scheithauer@siemens.com>
---
src/device/i2c_bus.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 70 insertions(+)
(limited to 'src/device')
diff --git a/src/device/i2c_bus.c b/src/device/i2c_bus.c
index 8368c247b8..f0d7dd116e 100644
--- a/src/device/i2c_bus.c
+++ b/src/device/i2c_bus.c
@@ -183,3 +183,73 @@ int i2c_dev_read_at16(struct device *const dev, uint8_t *const buf, const size_t
return -1;
}
}
+
+int i2c_dev_read_at(struct device *const dev, uint8_t *const buf, const size_t len,
+ uint8_t off)
+{
+ struct device *const busdev = i2c_busdev(dev);
+ if (!busdev)
+ return -1;
+
+ if (busdev->ops->ops_i2c_bus) {
+ const struct i2c_msg msg[] = {
+ {
+ .flags = 0,
+ .slave = dev->path.i2c.device,
+ .buf = &off,
+ .len = sizeof(off),
+ },
+ {
+ .flags = I2C_M_RD,
+ .slave = dev->path.i2c.device,
+ .buf = buf,
+ .len = len,
+ },
+ };
+
+ const int ret = busdev->ops->ops_i2c_bus->transfer(busdev, msg,
+ ARRAY_SIZE(msg));
+ if (ret)
+ return ret;
+ else
+ return len;
+ } else {
+ printk(BIOS_ERR, "%s Missing ops_i2c_bus->transfer", dev_path(busdev));
+ return -1;
+ }
+}
+
+int i2c_dev_write_at(struct device *const dev, uint8_t *const buf, const size_t len,
+ uint8_t off)
+{
+ struct device *const busdev = i2c_busdev(dev);
+ if (!busdev)
+ return -1;
+
+ if (busdev->ops->ops_i2c_bus) {
+ const struct i2c_msg msg[] = {
+ {
+ .flags = 0,
+ .slave = dev->path.i2c.device,
+ .buf = &off,
+ .len = sizeof(off),
+ },
+ {
+ .flags = I2C_M_NOSTART,
+ .slave = dev->path.i2c.device,
+ .buf = buf,
+ .len = len,
+ },
+ };
+
+ const int ret = busdev->ops->ops_i2c_bus->transfer(busdev, msg,
+ ARRAY_SIZE(msg));
+ if (ret)
+ return ret;
+ else
+ return len;
+ } else {
+ printk(BIOS_ERR, "%s Missing ops_i2c_bus->transfer", dev_path(busdev));
+ return -1;
+ }
+}
--
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