boards: atsame54_xpro: Support driving on-board LED with PWM

This commit adds the PWM LED definition in the board device tree for the on-board LED connected to the pin PC18. Signed-off-by: Stephanos Ioannidis <[email protected]>
crespum · Jul 4, 2020 · 17e8a20 · 17e8a20
1 parent 11c294d
commit 17e8a20
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diff --git a/boards/arm/atsame54_xpro/atsame54_xpro.dts b/boards/arm/atsame54_xpro/atsame54_xpro.dts
@@ -21,6 +21,7 @@
 	/* These aliases are provided for compatibility with samples */
 	aliases {
 		led0 = &led0;
+		pwm-led0 = &pwm_led0;
 		sw0 = &button0;
 		i2c-0 = &sercom7;
 	};
@@ -33,6 +34,13 @@
 		};
 	};
 
+	pwmleds {
+		compatible = "pwm-leds";
+		pwm_led0: pwm_led_0 {
+			pwms = <&tcc0 2>;
+		};
+	};
+
 	buttons {
 		compatible = "gpio-keys";
 		button0: button_0 {
@@ -42,6 +50,14 @@
 	};
 };
 
+&tcc0 {
+	status = "okay";
+	compatible = "atmel,sam0-tcc-pwm";
+	/* Gives a maximum period of 1.1s for 120MHz main clock */
+	prescaler = <8>;
+	#pwm-cells = <1>;
+};
+
 &sercom2 {
 	status = "okay";
 	compatible = "atmel,sam0-uart";

diff --git a/boards/arm/atsame54_xpro/atsame54_xpro.yaml b/boards/arm/atsame54_xpro/atsame54_xpro.yaml
@@ -12,6 +12,7 @@ toolchain:
   - xtools
 supported:
   - gpio
+  - pwm
   - spi
   - i2c
   - usb_device

diff --git a/boards/arm/atsame54_xpro/doc/index.rst b/boards/arm/atsame54_xpro/doc/index.rst
@@ -58,6 +58,8 @@ features:
 +-----------+------------+--------------------------------------+
 | GPIO      | on-chip    | I/O ports                            |
 +-----------+------------+--------------------------------------+
+| PWM       | on-chip    | Pulse Width Modulation               |
++-----------+------------+--------------------------------------+
 | USART     | on-chip    | Serial ports                         |
 +-----------+------------+--------------------------------------+
 | SPI       | on-chip    | Serial Peripheral Interface ports    |
@@ -88,7 +90,7 @@ Default Zephyr Peripheral Mapping:
 ----------------------------------
 - SERCOM2 USART TX : PB24
 - SERCOM2 USART RX : PB25
-- GPIO LED0        : PC18
+- GPIO/PWM LED0    : PC18
 - GPIO SW0         : PB31
 
 System Clock
@@ -105,6 +107,13 @@ this BSP. SERCOM2 is the default Zephyr console.
 
 - SERCOM2 115200 8n1 connected to the onboard Atmel Embedded Debugger (EDBG)
 
+PWM
+===
+
+The SAME54 MCU has 5 TCC based PWM units with up to 6 outputs each and a period
+of 24 bits or 16 bits.  If :code:`CONFIG_PWM_SAM0_TCC` is enabled then LED0 is
+driven by TCC0 instead of by GPIO.
+
 SPI Port
 ========
 

diff --git a/boards/arm/atsame54_xpro/pinmux.c b/boards/arm/atsame54_xpro/pinmux.c
@@ -105,6 +105,11 @@ static int board_pinmux_init(struct device *dev)
 	pinmux_pin_set(muxd, 9, PINMUX_FUNC_C);
 #endif
 
+#if (ATMEL_SAM0_DT_TCC_CHECK(0, atmel_sam0_tcc_pwm) && CONFIG_PWM_SAM0_TCC)
+	/* TCC0 on WO2=PC18 */
+	pinmux_pin_set(muxc, 18, PINMUX_FUNC_F);
+#endif
+
 #ifdef CONFIG_USB_DC_SAM0
 	/* USB DP on PA25, USB DM on PA24 */
 	pinmux_pin_set(muxa, 25, PINMUX_FUNC_H);
-Original file line number
+Diff line change
@@ Expand Up / @@ -12,6 +12,7 @@ toolchain: @@
       - xtools
     supported:
       - gpio
+      - pwm
       - spi
       - i2c
       - usb_device
@@ Expand Down @@