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-rw-r--r--nuttx/arch/arm/src/tiva/tiva_gpio.c12
-rw-r--r--nuttx/arch/arm/src/tiva/tiva_i2c.c12
-rw-r--r--nuttx/arch/arm/src/tiva/tiva_lowputc.c23
-rw-r--r--nuttx/arch/arm/src/tiva/tiva_ssi.c27
4 files changed, 58 insertions, 16 deletions
diff --git a/nuttx/arch/arm/src/tiva/tiva_gpio.c b/nuttx/arch/arm/src/tiva/tiva_gpio.c
index e2fae8f2a..99c1a7058 100644
--- a/nuttx/arch/arm/src/tiva/tiva_gpio.c
+++ b/nuttx/arch/arm/src/tiva/tiva_gpio.c
@@ -835,9 +835,17 @@ int tiva_configgpio(uint32_t cfgset)
flags = irqsave();
- /* Enable power and clocking for this GPIO peripheral. */
+ /* Enable power and clocking for this GPIO peripheral.
+ *
+ * - Enable Power (TM4C129 family only): Applies power (only) to the GPIO
+ * peripheral. This is not an essential step since enabling clocking
+ * will also apply power. The only significance is that the GPIO state
+ * will be retained if the GPIO clocking is subsequently disabled.
+ * - Enable Clocking (All families): Applies both power and clocking to
+ * the GPIO peripheral, bringing it a fully functional state.
+ */
- tiva_gpio_enablepwr(port); /* State will be retained of clocking disabled */
+ tiva_gpio_enablepwr(port);
tiva_gpio_enableclk(port);
/* First, set the port to digital input. This is the safest state in which
diff --git a/nuttx/arch/arm/src/tiva/tiva_i2c.c b/nuttx/arch/arm/src/tiva/tiva_i2c.c
index 657b5349f..bab0e32ea 100644
--- a/nuttx/arch/arm/src/tiva/tiva_i2c.c
+++ b/nuttx/arch/arm/src/tiva/tiva_i2c.c
@@ -1520,10 +1520,18 @@ static int tiva_i2c_initialize(struct tiva_i2c_priv_s *priv, uint32_t frequency)
i2cvdbg("I2C%d: refs=%d\n", config->devno, priv->refs);
- /* Enable clocking to the I2C peripheral */
+ /* Enable power and clocking to the I2C peripheral.
+ *
+ * - Enable Power (TM4C129 family only): Applies power (only) to the I2C
+ * peripheral. This is not an essential step since enabling clocking
+ * will also apply power. The only significance is that the I2C state
+ * will be retained if the I2C clocking is subsequently disabled.
+ * - Enable Clocking (All families): Applies both power and clocking to
+ * the I2C peripheral, bringing it a fully functional state.
+ */
#ifdef TIVA_SYSCON_RCGCI2C
- tiva_i2c_enablepwr(config->devno); /* State will be retained if clocking stopped */
+ tiva_i2c_enablepwr(config->devno);
tiva_i2c_enableclk(config->devno);
i2cvdbg("I2C%d: RCGI2C[%08x]=%08x\n",
diff --git a/nuttx/arch/arm/src/tiva/tiva_lowputc.c b/nuttx/arch/arm/src/tiva/tiva_lowputc.c
index 740495d55..5c0d6eaa1 100644
--- a/nuttx/arch/arm/src/tiva/tiva_lowputc.c
+++ b/nuttx/arch/arm/src/tiva/tiva_lowputc.c
@@ -255,10 +255,17 @@ void up_lowsetup(void)
/* Enable the selected UARTs and configure GPIO pins needed by the
* the selected UARTs. NOTE: The serial driver later depends on
* this pin configuration -- whether or not a serial console is selected.
+ *
+ * - Enable Power (TM4C129 family only): Applies power (only) to the UART
+ * peripheral. This is not an essential step since enabling clocking
+ * will also apply power. The only significance is that the UART state
+ * will be retained if the UART clocking is subsequently disabled.
+ * - Enable Clocking (All families): Applies both power and clocking to
+ * the UART peripheral, bringing it a fully functional state.
*/
#ifdef CONFIG_TIVA_UART0
- tiva_uart0_enablepwr(); /* State will be retained if clocking disabled */
+ tiva_uart0_enablepwr();
tiva_uart0_enableclk();
tiva_configgpio(GPIO_UART0_RX);
@@ -266,7 +273,7 @@ void up_lowsetup(void)
#endif
#ifdef CONFIG_TIVA_UART1
- tiva_uart1_enablepwr(); /* State will be retained if clocking disabled */
+ tiva_uart1_enablepwr();
tiva_uart1_enableclk();
tiva_configgpio(GPIO_UART1_RX);
@@ -274,7 +281,7 @@ void up_lowsetup(void)
#endif
#ifdef CONFIG_TIVA_UART2
- tiva_uart2_enablepwr(); /* State will be retained if clocking disabled */
+ tiva_uart2_enablepwr();
tiva_uart2_enableclk();
tiva_configgpio(GPIO_UART2_RX);
@@ -282,7 +289,7 @@ void up_lowsetup(void)
#endif
#ifdef CONFIG_TIVA_UART3
- tiva_uart3_enablepwr(); /* State will be retained if clocking disabled */
+ tiva_uart3_enablepwr();
tiva_uart3_enableclk();
tiva_configgpio(GPIO_UART3_RX);
@@ -290,7 +297,7 @@ void up_lowsetup(void)
#endif
#ifdef CONFIG_TIVA_UART4
- tiva_uart4_enablepwr(); /* State will be retained if clocking disabled */
+ tiva_uart4_enablepwr();
tiva_uart4_enableclk();
tiva_configgpio(GPIO_UART4_RX);
@@ -298,7 +305,7 @@ void up_lowsetup(void)
#endif
#ifdef CONFIG_TIVA_UART5
- tiva_uart5_enablepwr(); /* State will be retained if clocking disabled */
+ tiva_uart5_enablepwr();
tiva_uart5_enableclk();
tiva_configgpio(GPIO_UART5_RX);
@@ -306,7 +313,7 @@ void up_lowsetup(void)
#endif
#ifdef CONFIG_TIVA_UART6
- tiva_uart6_enablepwr(); /* State will be retained if clocking disabled */
+ tiva_uart6_enablepwr();
tiva_uart6_enableclk();
tiva_configgpio(GPIO_UART6_RX);
@@ -314,7 +321,7 @@ void up_lowsetup(void)
#endif
#ifdef CONFIG_TIVA_UART7
- tiva_uart7_enablepwr(); /* State will be retained if clocking disabled */
+ tiva_uart7_enablepwr();
tiva_uart7_enableclk();
tiva_configgpio(GPIO_UART7_RX);
diff --git a/nuttx/arch/arm/src/tiva/tiva_ssi.c b/nuttx/arch/arm/src/tiva/tiva_ssi.c
index 36c89d488..c313a7231 100644
--- a/nuttx/arch/arm/src/tiva/tiva_ssi.c
+++ b/nuttx/arch/arm/src/tiva/tiva_ssi.c
@@ -1475,9 +1475,18 @@ FAR struct spi_dev_s *up_spiinitialize(int port)
priv = &g_ssidev[SSI0_NDX];
- /* Enable power and clocking to the SSI0 peripheral */
+ /* Enable power and clocking to the SSI0 peripheral.
+ *
+ * - Enable Power (TM4C129 family only): Applies power (only) to the
+ * SSI0 peripheral. This is not an essential step since enabling
+ * clocking will also apply power. The only significance is that
+ * the SSI0 state will be retained if the SSI0 clocking is
+ * subsequently disabled.
+ * - Enable Clocking (All families): Applies both power and clocking
+ * to the SSI0 peripheral, bringing it a fully functional state.
+ */
- tiva_ssi0_enablepwr(); /* State will be ratained if clocking disabled */
+ tiva_ssi0_enablepwr();
tiva_ssi0_enableclk();
/* Configure SSI0 GPIOs (NOTE that SS is not initialized here, the
@@ -1497,9 +1506,19 @@ FAR struct spi_dev_s *up_spiinitialize(int port)
priv = &g_ssidev[SSI1_NDX];
- /* Enable power and clocking to the SSI1 peripheral */
+ /* Enable power and clocking to the SSI1 peripheral.
+ *
+ * - Enable Power (TM4C129 family only): Applies power (only) to the
+ * SSI1 peripheral. This is not an essential step since enabling
+ * clocking will also apply power. The only significance is that
+ * the SSI1 state will be retained if the SSI1 clocking is
+ * subsequently disabled.
+ * - Enable Clocking (All families): Applies both power and clocking
+ * to the SSI1 peripheral, bringing it a fully functional state.
+ */
+
- tiva_ssi1_enablepwr(); /* State will be ratained if clocking disabled */
+ tiva_ssi1_enablepwr();
tiva_ssi1_enableclk();
/* Configure SSI1 GPIOs */
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-20 18:35:41 +0000