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authorNico Huber <nico.huber@secunet.com>2017-11-01 13:15:33 +0100
committerPatrick Georgi <pgeorgi@google.com>2019-09-30 11:50:16 +0000
commit9734af669768203349485bd76a4ad3c79c8bdc73 (patch)
tree7395ab22c71f5e5a7b6f12b8e71aa449ba47cf2e
parent9529530766ed6f1ed17c2af11d51deca9a2092d6 (diff)
downloadcoreboot-9734af669768203349485bd76a4ad3c79c8bdc73.tar.xz
device/i2c_bus: Add i2c_dev_read_at16()
i2c_dev_read_at16() sends a 16-bit offset to the I2C chip (for larger EEPROM parts), then reads bytes up to a given length into a buffer. Change-Id: I7516f3e5d9aca362c2b340aa5627d91510c09412 Signed-off-by: Nico Huber <nico.huber@secunet.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/29478 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
-rw-r--r--src/device/i2c_bus.c37
-rw-r--r--src/include/device/i2c_bus.h8
2 files changed, 45 insertions, 0 deletions
diff --git a/src/device/i2c_bus.c b/src/device/i2c_bus.c
index 30bb80ca98..93634d223b 100644
--- a/src/device/i2c_bus.c
+++ b/src/device/i2c_bus.c
@@ -16,6 +16,7 @@
#include <console/console.h>
#include <device/smbus.h>
#include <device/i2c_bus.h>
+#include <commonlib/endian.h>
struct bus *i2c_link(struct device *const dev)
{
@@ -159,3 +160,39 @@ int i2c_dev_writeb_at(struct device *const dev,
return -1;
}
}
+
+int i2c_dev_read_at16(struct device *const dev,
+ uint8_t *const buf, const size_t len, uint16_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 = (uint8_t *)&off,
+ .len = sizeof(off),
+ },
+ {
+ .flags = I2C_M_RD,
+ .slave = dev->path.i2c.device,
+ .buf = buf,
+ .len = len,
+ },
+ };
+
+ write_be16(&off, off);
+ 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;
+ }
+}
diff --git a/src/include/device/i2c_bus.h b/src/include/device/i2c_bus.h
index 6aa4f9ba9d..5302d20228 100644
--- a/src/include/device/i2c_bus.h
+++ b/src/include/device/i2c_bus.h
@@ -89,4 +89,12 @@ int i2c_dev_readb_at(struct device *, uint8_t off);
*/
int i2c_dev_writeb_at(struct device *, uint8_t off, uint8_t val);
+/*
+ * Sends the 16-bit register offset `off` and reads `len` bytes into `buf`.
+ *
+ * Returns the number of bytes read on success, negative `enum cb_err`
+ * value on error.
+ */
+int i2c_dev_read_at16(struct device *, uint8_t *buf, size_t len, uint16_t off);
+
#endif /* _DEVICE_I2C_BUS_H_ */