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in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git
The following commit(s) were added to refs/heads/master by this push:
new b6fbcb6 nrf52: Add a static copy buffer for i2c
b6fbcb6 is described below
commit b6fbcb649c29d6e1f7052756f2099a1f3424a30f
Author: Brennan Ashton <bash...@brennanashton.com>
AuthorDate: Sun Jan 17 14:18:12 2021 -0800
nrf52: Add a static copy buffer for i2c
Signed-off-by: Brennan Ashton <bash...@brennanashton.com>
---
arch/arm/src/nrf52/Kconfig | 19 +++++++++++++++++++
arch/arm/src/nrf52/nrf52_i2c.c | 24 +++++++++++++++++++-----
2 files changed, 38 insertions(+), 5 deletions(-)
diff --git a/arch/arm/src/nrf52/Kconfig b/arch/arm/src/nrf52/Kconfig
index 6a4fc9a..89a8742 100644
--- a/arch/arm/src/nrf52/Kconfig
+++ b/arch/arm/src/nrf52/Kconfig
@@ -632,5 +632,24 @@ menu "I2C Master Configuration"
config NRF52_I2C_MASTER_DISABLE_NOSTART
bool "Disable the I2C Master NOSTART flag support"
default n
+ ---help---
+ To combine two i2c messages that are part of a
+ single transaction (NO_STOP-NO_START) the nrf52
+ hardware requires these be joined into a single
+ transfer. This can be expensive and some devices
+ can get away with multi-part transfers as separate
+ transfers. Enable this at your own risk!
+
+config NRF52_I2C_MASTER_COPY_BUF_SIZE
+ int "Static buffer size for NOSTART flag support"
+ depends on !NRF52_I2C_MASTER_DISABLE_NOSTART
+ default 4
+ ---help---
+ To combine two i2c messages that are part of a
+ single transaction (NO_STOP-NO_START) the nrf52
+ hardware requires these be joined into a single
+ transfer. This static buffer will be used if the
+ transaction will fit otherwise it will fall back
+ on malloc.
endmenu
diff --git a/arch/arm/src/nrf52/nrf52_i2c.c b/arch/arm/src/nrf52/nrf52_i2c.c
index 2a4233f..c189a53 100644
--- a/arch/arm/src/nrf52/nrf52_i2c.c
+++ b/arch/arm/src/nrf52/nrf52_i2c.c
@@ -68,6 +68,11 @@ struct nrf52_i2c_priv_s
uint8_t msgc; /* Message count */
struct i2c_msg_s *msgv; /* Message list */
uint8_t *ptr; /* Current message buffer */
+#ifdef CONFIG_NRF52_I2C_MASTER_COPY_BUF_SIZE
+ /* Static buffer used for continued messages */
+
+ uint8_t copy_buf[CONFIG_NRF52_I2C_MASTER_COPY_BUF_SIZE];
+#endif
uint32_t freq; /* Current I2C frequency */
int dcnt; /* Current message length */
uint16_t flags; /* Current message flags */
@@ -308,11 +313,20 @@ static int nrf52_i2c_transfer(FAR struct i2c_master_s
*dev,
/* Combine buffers */
- pack_buf = kmm_malloc(priv->msgv[0].length +
- priv->msgv[1].length);
- if (pack_buf == NULL)
+ if ((priv->msgv[0].length +
+ priv->msgv[1].length) <=
+ CONFIG_NRF52_I2C_MASTER_COPY_BUF_SIZE)
+ {
+ pack_buf = priv->copy_buf;
+ }
+ else
{
- return -1;
+ pack_buf = kmm_malloc(priv->msgv[0].length +
+ priv->msgv[1].length);
+ if (pack_buf == NULL)
+ {
+ return -ENOMEM;
+ }
}
/* Combine messages */
@@ -496,7 +510,7 @@ static int nrf52_i2c_transfer(FAR struct i2c_master_s *dev,
errout:
#ifndef CONFIG_NRF52_I2C_MASTER_DISABLE_NOSTART
- if (pack_buf != NULL)
+ if (pack_buf != NULL && pack_buf != priv->copy_buf)
{
kmm_free(pack_buf);
}
