From 3bc866395cc755f344d341a7f0b13b99d641cb0f Mon Sep 17 00:00:00 2001
From: Nhan Cao <93050378+AnhNhan2803@users.noreply.github.com>
Date: Fri, 30 Aug 2024 11:55:25 -0600
Subject: [PATCH] Adding I2C Burst Reading/Writing feature (#1495)

* Adding I2C Burst Reading/Writing feature

* Add functions to header file.

Fixing: https://github.com/raspberrypi/pico-sdk/pull/1495

* Some missing changes

Rename the functions. Lose the "mode" and "blocking" needs to be at the
end.
Just set restart_on_next in the caller rather than adding a parameter.

---------

Co-authored-by: anhnhancao <nhan@earable.ai>
Co-authored-by: Peter Harper <peter.harper@raspberrypi.com>
---
 src/rp2_common/hardware_i2c/i2c.c             | 12 ++++++++
 .../hardware_i2c/include/hardware/i2c.h       | 29 +++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/src/rp2_common/hardware_i2c/i2c.c b/src/rp2_common/hardware_i2c/i2c.c
index 865c16f3..0bf88eb5 100644
--- a/src/rp2_common/hardware_i2c/i2c.c
+++ b/src/rp2_common/hardware_i2c/i2c.c
@@ -259,6 +259,12 @@ int i2c_write_timeout_per_char_us(i2c_inst_t *i2c, uint8_t addr, const uint8_t *
                                        init_per_iteration_timeout_us(&ts, timeout_per_char_us), &ts);
 }
 
+int i2c_write_burst_blocking(i2c_inst_t *i2c, uint8_t addr, const uint8_t *src, size_t len) {
+    int rc = i2c_write_blocking_internal(i2c, addr, src, len, true, NULL, NULL);
+    i2c->restart_on_next = false;
+    return rc;
+}
+
 static int i2c_read_blocking_internal(i2c_inst_t *i2c, uint8_t addr, uint8_t *dst, size_t len, bool nostop,
                                check_timeout_fn timeout_check, timeout_state_t *ts) {
     invalid_params_if(HARDWARE_I2C, addr >= 0x80); // 7-bit addresses
@@ -341,3 +347,9 @@ int i2c_read_timeout_per_char_us(i2c_inst_t *i2c, uint8_t addr, uint8_t *dst, si
     return i2c_read_blocking_internal(i2c, addr, dst, len, nostop,
                                       init_per_iteration_timeout_us(&ts, timeout_per_char_us), &ts);
 }
+
+int i2c_read_burst_blocking(i2c_inst_t *i2c, uint8_t addr, uint8_t *dst, size_t len) {
+    int rc = i2c_read_blocking_internal(i2c, addr, dst, len, true, NULL, NULL);
+    i2c->restart_on_next = false;
+    return rc;
+}
diff --git a/src/rp2_common/hardware_i2c/include/hardware/i2c.h b/src/rp2_common/hardware_i2c/include/hardware/i2c.h
index 13bafcc2..9a9cdb08 100644
--- a/src/rp2_common/hardware_i2c/include/hardware/i2c.h
+++ b/src/rp2_common/hardware_i2c/include/hardware/i2c.h
@@ -316,6 +316,21 @@ int i2c_read_timeout_per_char_us(i2c_inst_t *i2c, uint8_t addr, uint8_t *dst, si
  */
 int i2c_write_blocking(i2c_inst_t *i2c, uint8_t addr, const uint8_t *src, size_t len, bool nostop);
 
+/*! \brief Attempt to write specified number of bytes to address, blocking in burst mode
+ *  \ingroup hardware_i2c
+ *
+ * This version of the function will not issue a stop and will not restart on the next write.
+ * This allows you to write consecutive bytes of data without having to resend a stop bit and
+ * (for example) without having to send address byte(s) repeatedly
+ *
+ * \param i2c Either \ref i2c0 or \ref i2c1
+ * \param addr 7-bit address of device to read from
+ * \param dst Pointer to buffer to receive data
+ * \param len Length of data in bytes to receive
+ * \return Number of bytes read, or PICO_ERROR_GENERIC if address not acknowledged or no device present.
+ */
+int i2c_write_burst_blocking(i2c_inst_t *i2c, uint8_t addr, const uint8_t *src, size_t len);
+
 /*! \brief  Attempt to read specified number of bytes from address, blocking
  *  \ingroup hardware_i2c
  *
@@ -329,6 +344,20 @@ int i2c_write_blocking(i2c_inst_t *i2c, uint8_t addr, const uint8_t *src, size_t
  */
 int i2c_read_blocking(i2c_inst_t *i2c, uint8_t addr, uint8_t *dst, size_t len, bool nostop);
 
+/*! \brief  Attempt to read specified number of bytes from address, blocking in burst mode
+ *  \ingroup hardware_i2c
+ *
+ * This version of the function will not issue a stop and will not restart on the next read.
+ * This allows you to read consecutive bytes of data without having to resend a stop bit and
+ * (for example) without having to send address byte(s) repeatedly
+ *
+ * \param i2c Either \ref i2c0 or \ref i2c1
+ * \param addr 7-bit address of device to read from
+ * \param dst Pointer to buffer to receive data
+ * \param len Length of data in bytes to receive
+ * \return Number of bytes read, or PICO_ERROR_GENERIC if address not acknowledged or no device present.
+ */
+int i2c_read_burst_blocking(i2c_inst_t *i2c, uint8_t addr, uint8_t *dst, size_t len);
 
 /*! \brief Determine non-blocking write space available
  *  \ingroup hardware_i2c