From 4e9bd00dfbbd5b4d11ebc020b8722789d3bf138f Mon Sep 17 00:00:00 2001
From: Florian Weber <Florian.Weber@live.de>
Date: Fri, 10 Jan 2025 10:25:00 +0100
Subject: [PATCH] drivers: i2c: rtio

extend i2c library to create rtio sqes for reading and writing bytes

Signed-off-by: Florian Weber <Florian.Weber@live.de>
---
 drivers/i2c/i2c_rtio.c       | 41 ++++++++++++++++++++++++++++++++++++
 include/zephyr/drivers/i2c.h | 29 +++++++++++++++++++++++++
 2 files changed, 70 insertions(+)

diff --git a/drivers/i2c/i2c_rtio.c b/drivers/i2c/i2c_rtio.c
index d921f5604ef..a44e2e61fee 100644
--- a/drivers/i2c/i2c_rtio.c
+++ b/drivers/i2c/i2c_rtio.c
@@ -52,6 +52,47 @@ struct rtio_sqe *i2c_rtio_copy(struct rtio *r, struct rtio_iodev *iodev, const s
 	return sqe;
 }
 
+struct rtio_sqe *i2c_rtio_copy_reg_write_byte(struct rtio *r, struct rtio_iodev *iodev,
+					      uint8_t reg_addr, uint8_t data)
+{
+	uint8_t msg[2];
+
+	struct rtio_sqe *sqe = rtio_sqe_acquire(r);
+
+	if (sqe == NULL) {
+		rtio_sqe_drop_all(r);
+		return NULL;
+	}
+	msg[0] = reg_addr;
+	msg[1] = data;
+	rtio_sqe_prep_tiny_write(sqe, iodev, RTIO_PRIO_NORM, msg, sizeof(msg), NULL);
+	sqe->iodev_flags = RTIO_IODEV_I2C_STOP;
+	return sqe;
+}
+
+struct rtio_sqe *i2c_rtio_copy_reg_burst_read(struct rtio *r, struct rtio_iodev *iodev,
+					      uint8_t start_addr, void *buf, size_t num_bytes)
+{
+	struct rtio_sqe *sqe = rtio_sqe_acquire(r);
+
+	if (sqe == NULL) {
+		rtio_sqe_drop_all(r);
+		return NULL;
+	}
+	rtio_sqe_prep_tiny_write(sqe, iodev, RTIO_PRIO_NORM, &start_addr, 1, NULL);
+	sqe->flags |= RTIO_SQE_TRANSACTION;
+
+	sqe = rtio_sqe_acquire(r);
+	if (sqe == NULL) {
+		rtio_sqe_drop_all(r);
+		return NULL;
+	}
+	rtio_sqe_prep_read(sqe, iodev, RTIO_PRIO_NORM, buf, num_bytes, NULL);
+	sqe->iodev_flags |= RTIO_IODEV_I2C_STOP | RTIO_IODEV_I2C_RESTART;
+
+	return sqe;
+}
+
 void i2c_rtio_init(struct i2c_rtio *ctx, const struct device *dev)
 {
 	k_sem_init(&ctx->lock, 1, 1);
diff --git a/include/zephyr/drivers/i2c.h b/include/zephyr/drivers/i2c.h
index 5f1c3fbe8ae..d8eaee81873 100644
--- a/include/zephyr/drivers/i2c.h
+++ b/include/zephyr/drivers/i2c.h
@@ -1092,6 +1092,35 @@ struct rtio_sqe *i2c_rtio_copy(struct rtio *r,
 			       const struct i2c_msg *msgs,
 			       uint8_t num_msgs);
 
+/**
+ * @brief Copy the register address and data to a SQE
+ *
+ * @param r RTIO context
+ * @param iodev RTIO IODev to target for the submissions
+ * @param reg_addr target register address
+ * @param data data to be written
+ *
+ * @retval sqe Last submission in the queue added
+ * @retval NULL Not enough memory in the context to copy the requests
+ */
+struct rtio_sqe *i2c_rtio_copy_reg_write_byte(struct rtio *r, struct rtio_iodev *iodev,
+					      uint8_t reg_addr, uint8_t data);
+
+/**
+ * @brief acquire and configure a i2c burst read transmission
+ *
+ * @param r RTIO context
+ * @param iodev RTIO IODev to target for the submissions
+ * @param start_addr target register address
+ * @param buf Memory pool that stores the retrieved data.
+ * @param num_bytes Number of bytes to read.
+ *
+ * @retval sqe Last submission in the queue added
+ * @retval NULL Not enough memory in the context to copy the requests
+ */
+struct rtio_sqe *i2c_rtio_copy_reg_burst_read(struct rtio *r, struct rtio_iodev *iodev,
+					      uint8_t start_addr, void *buf, size_t num_bytes);
+
 #endif /* CONFIG_I2C_RTIO */
 
 /**