arm64/am62x: Add TISCI client, GPIO and I2C drivers

On K3 SoCs the A53 cluster does not own device power, clocks, resets or
interrupt routing; these are managed by the DM/TIFS firmware and requested
over TISCI through the secure-proxy mailbox.  Add:

  - a TISCI client (secure-proxy transport plus device/clock/reset helpers)
  - a GPIO driver for banks 0/1 with pad mux and TISCI power-on
  - an OMAP-I2C driver for the main-domain I2C controllers

and wire them into the PocketBeagle2 and BeaglePlay bring-up.

Tested on PocketBeagle2 (SYSFW 11.2.5) with the TechLab cape attached:

  nsh> i2c bus
  nsh> i2c dev -b 0 0x03 0x77   # I2C0 detects onboard 0x20 and 0x50
  nsh> gpio -o 1 /dev/gpio3     # drives a user LED; read back with:
  nsh> gpio /dev/gpio3

Signed-off-by: Piyush Patle <piyushpatle228@gmail.com>

Author: PiyushPatle26

Documentation/platforms/arm64/am62x/boards/beagleplay/index.rst

@@ -18,10 +18,11 @@ Features
 * Four user LEDs
 * Gigabit Ethernet, USB, Wi-Fi, and Bluetooth hardware on the board
 
-Current NuttX support is limited to early boot, the 16550 serial console,
-interactive NSH, and ``procfs`` mount during board bring-up. GPIO, LEDs,
-I2C, SPI, MMC/SD, Ethernet, Wi-Fi, Bluetooth, and USB runtime support are
-not implemented yet.
+Current NuttX support includes early boot, the 16550 serial console,
+interactive NSH, ``procfs`` mount during board bring-up, AM62x TISCI
+initialization, main-domain GPIO, and I2C0/I2C1 controller support in the
+``beagleplay:i2c`` configuration. SPI, MMC/SD, Ethernet, Wi-Fi, Bluetooth,
+and USB runtime support are not implemented yet.
 
 Buttons and LEDs
 ================
@@ -37,8 +38,8 @@ USR2    GPIO1_24  Red user LED
 USR3    GPIO1_25  Blue user LED
 ======  ========  ==================
 
-The current NuttX port does not yet provide functional GPIO-backed LED
-control. The ``CONFIG_ARCH_LEDS`` hooks are present as placeholders only.
+The current NuttX port initializes the AM62x GPIO controller. Automatic
+``CONFIG_ARCH_LEDS`` LED hooks remain placeholders only.
 
 Serial Console
 ==============
@@ -57,7 +58,9 @@ Interface    SoC signal              Notes
 ===========  ======================  =======================================
 DEBUG USB-C  UART0                   Default NuttX serial console
 microSD      MMC1                    Validated boot media for ``nuttx.bin``
-USR0-3       GPIO1_22 through 1_25   User LEDs, not yet driven by NuttX
+USR0-3       GPIO1_22 through 1_25   User LEDs on the main GPIO block
+I2C0         I2C0                    Available in ``beagleplay:i2c``
+I2C1         I2C1                    Available in ``beagleplay:i2c``
 ===========  ======================  =======================================
 
 Power Supply
@@ -116,5 +119,8 @@ Configurations
 ``beagleplay:nsh``
   Interactive NSH configuration for serial bring-up and shell access.
 
+``beagleplay:i2c``
+  NSH configuration with AM62x I2C0/I2C1 and the ``i2c`` tool enabled.
+
 ``beagleplay:ostest``
   Hardware validation configuration that boots directly into ``ostest_main``.

Documentation/platforms/arm64/am62x/boards/pocketbeagle2/index.rst

@@ -17,10 +17,11 @@ Features
 * Expansion headers for GPIO, I2C, SPI, UART, PWM, and ADC
 * User LEDs exposed by the board port
 
-Current NuttX support is limited to early boot, the 16550 serial console,
-interactive NSH, and ``procfs`` mount during board bring-up. GPIO, functional
-LED control, I2C, SPI, MMC/SD runtime support, Ethernet, and USB runtime
-support are not implemented yet.
+Current NuttX support includes early boot, the 16550 serial console,
+interactive NSH, ``procfs`` mount during board bring-up, AM62x TISCI
+initialization, main-domain GPIO, and I2C0/I2C2 controller support in the
+``pocketbeagle2:i2c`` configuration. SPI, MMC/SD runtime support, Ethernet,
+and USB runtime support are not implemented yet.
 
 Buttons and LEDs
 ================
@@ -35,7 +36,8 @@ USR1    Amber     ``CONFIG_ARCH_LEDS`` placeholder
 USR2    Red       ``CONFIG_ARCH_LEDS`` placeholder
 ======  ========  =====================
 
-These LEDs are not driven yet because AM62x GPIO support has not been added.
+The AM62x GPIO controller is initialized by the board port. Automatic
+``CONFIG_ARCH_LEDS`` LED hooks remain placeholders only.
 
 Serial Console
 ==============
@@ -54,7 +56,9 @@ Interface    SoC signal              Notes
 ===========  ======================  =======================================
 USB-C debug  UART6                   Default NuttX serial console
 microSD      MMC1                    Validated boot media for ``nuttx.bin``
-USR0-2       Board user LEDs         Not yet driven by NuttX GPIO support
+USR0-2       Board user LEDs         Available through the main GPIO block
+I2C0         I2C0                    Available in ``pocketbeagle2:i2c``
+I2C2         Header I2C2             Available in ``pocketbeagle2:i2c``
 ===========  ======================  =======================================
 
 Power Supply
@@ -106,5 +110,8 @@ Configurations
 ``pocketbeagle2:nsh``
   Interactive NSH configuration for serial bring-up and shell access.
 
+``pocketbeagle2:i2c``
+  NSH configuration with AM62x I2C0/I2C2 and the ``i2c`` tool enabled.
+
 ``pocketbeagle2:ostest``
   Hardware validation configuration that boots directly into ``ostest_main``.

Documentation/platforms/arm64/am62x/index.rst

@@ -10,6 +10,8 @@ Texas Instruments featuring:
 - **Boot:** ROM → R5 SYSFW (TIFS) → U-Boot SPL → U-Boot → NuttX
 - **Memory:** External DDR4/LPDDR4 (512 MB – 2 GB depending on board)
 - **UART:** Seven 16550-compatible UARTs (48 MHz clock)
+- **GPIO:** Main-domain GPIO controller support
+- **I2C:** Main-domain I2C controller support
 
 Supported Boards
 ================

arch/arm64/include/am62x/irq.h

@@ -102,4 +102,16 @@
 #define AM62X_IRQ_UART5           215   /* GIC_SPI 183                    */
 #define AM62X_IRQ_UART6           216   /* GIC_SPI 184                    */
 
+/* GPIO */
+
+#define AM62X_IRQ_GPIO0            57
+#define AM62X_IRQ_GPIO1            58
+
+/* I2C */
+
+#define AM62X_IRQ_I2C0            193   /* GIC_SPI 161 */
+#define AM62X_IRQ_I2C1            194   /* GIC_SPI 162 */
+#define AM62X_IRQ_I2C2            195   /* GIC_SPI 163 */
+#define AM62X_IRQ_I2C3            196   /* GIC_SPI 164 */
+
 #endif /* __ARCH_ARM64_INCLUDE_AM62X_IRQ_H */

arch/arm64/src/am62x/CMakeLists.txt

@@ -22,7 +22,11 @@
 
 # AM62x SoC sources that are always compiled
 
-list(APPEND SRCS am62x_boot.c am62x_16550serial.c)
+list(APPEND SRCS am62x_boot.c am62x_16550serial.c am62x_gpio.c am62x_i2c.c)
+
+if(CONFIG_AM62X_TISCI)
+  list(APPEND SRCS am62x_tisci.c)
+endif()
 
 # Early UART assembly (needed for CONFIG_ARCH_EARLY_PRINT / semihosting console
 # before the full serial driver is up)

arch/arm64/src/am62x/Kconfig

@@ -7,6 +7,94 @@
 
 if ARCH_CHIP_AM62X
 
-comment "AM62x peripheral selection is provided by board defconfig for now."
+menu "AM62x peripheral support"
+
+config AM62X_TISCI
+	bool "TISCI system controller (DM/TIFS) client"
+	default n
+	---help---
+		Enable the AM62x TISCI client.  On K3 SoCs the A53 does not own
+		device power, clocks, resets, or interrupt routing; those are
+		requested from the DM/TIFS firmware over the TISCI protocol via the
+		secure-proxy mailbox.  This driver provides the request helpers used
+		by peripheral drivers to power on a block, enable its functional
+		clock, release resets, and route its interrupt to the GIC.
+
+if AM62X_TISCI
+
+config AM62X_TISCI_HOST_ID
+	int "TISCI host ID"
+	default 12
+	---help---
+		Host ID this core presents to the DM/TIFS firmware.  Must match the
+		host allocation in the firmware boardcfg.  12 is the standard A53
+		HLOS host on AM62x.
+
+config AM62X_TISCI_RX_THREAD
+	int "Secure proxy RX (response) thread"
+	default 12
+	---help---
+		Secure-proxy thread the firmware uses to send responses back to this
+		host.
+
+config AM62X_TISCI_TX_THREAD
+	int "Secure proxy TX (request) thread"
+	default 13
+	---help---
+		Secure-proxy thread this host uses to send requests to the firmware.
+
+endif # AM62X_TISCI
+
+config AM62X_GPIO
+	bool "GPIO support"
+	default n
+	---help---
+		Enable the AM62x main-domain GPIO controller driver, including
+		basic GPIO input/output operations, pad-mux helper support, and
+		per-pin interrupt callback dispatch for GPIO0/GPIO1.
+
+config AM62X_GPIO_IRQ
+	bool "GPIO interrupt (GIC) delivery"
+	depends on AM62X_GPIO
+	default n
+	---help---
+		Enable per-bank GPIO interrupt delivery through the GIC.  On AM62x
+		the GPIO bank interrupts are routed through the main GPIO interrupt
+		router, which must be programmed over TISCI (RM_IRQ_SET) before the
+		GIC input line is valid.  Until that routing is implemented, leave
+		this disabled: enabling an unrouted GIC line faults at boot.  GPIO
+		input/output and the callback API still work without it.
+
+config AM62X_I2C0
+	bool "I2C0 support"
+	depends on I2C
+	default n
+
+config AM62X_I2C1
+	bool "I2C1 support"
+	depends on I2C
+	default n
+
+config AM62X_I2C2
+	bool "I2C2 support"
+	depends on I2C
+	default n
+
+config AM62X_I2C3
+	bool "I2C3 support"
+	depends on I2C
+	default n
+
+config AM62X_I2CTIMEOSEC
+	int "I2C transfer timeout seconds"
+	default 0
+	depends on AM62X_I2C0 || AM62X_I2C1 || AM62X_I2C2 || AM62X_I2C3
+
+config AM62X_I2CTIMEOMS
+	int "I2C transfer timeout milliseconds"
+	default 500
+	depends on AM62X_I2C0 || AM62X_I2C1 || AM62X_I2C2 || AM62X_I2C3
+
+endmenu
 
 endif # ARCH_CHIP_AM62X

arch/arm64/src/am62x/Make.defs

@@ -29,6 +29,13 @@ include common/Make.defs
 
 CHIP_CSRCS  = am62x_boot.c
 CHIP_CSRCS += am62x_16550serial.c
+CHIP_CSRCS += am62x_gpio.c
+CHIP_CSRCS += am62x_i2c.c
+
+ifeq ($(CONFIG_AM62X_TISCI),y)
+CHIP_CSRCS += am62x_tisci.c
+endif
+
 
 # Early UART assembly (only when CONFIG_ARCH_EARLY_PRINT is set, which
 # is selected automatically when CONFIG_ARCH_HAVE_LOWPUTC is enabled