drivers: counter: Add SAM0 basic counter support

This adds support for the basic timer counter (TC) found on SAM0
series parts.  This driver only supports running the counter
in 32 bit wide mode.  Since this mode explicitly slaves the odd
counters to the even ones, only instances of the even ones are
defined.

Tested with tests/drivers/counter/counter_basic_api on SAMD21.

Signed-off-by: Derek Hageman <[email protected]>

Author: Sizurka

drivers/counter/CMakeLists.txt

@@ -12,5 +12,6 @@ zephyr_library_sources_ifdef(CONFIG_COUNTER_NRF_TIMER           counter_nrfx_tim
 zephyr_library_sources_ifdef(CONFIG_COUNTER_NRF_RTC             counter_nrfx_rtc.c)
 zephyr_library_sources_ifdef(CONFIG_RTC_QMSI 			counter_rtc_qmsi.c)
 zephyr_library_sources_ifdef(CONFIG_COUNTER_RTC_STM32           counter_ll_stm32_rtc.c)
+zephyr_library_sources_ifdef(CONFIG_COUNTER_SAM0_TC32           counter_sam0_tc32.c)
 
 zephyr_library_sources_ifdef(CONFIG_USERSPACE   counter_handlers.c)

drivers/counter/Kconfig

@@ -34,4 +34,6 @@ source "drivers/counter/Kconfig.imx_epit"
 
 source "drivers/counter/Kconfig.stm32_rtc"
 
+source "drivers/counter/Kconfig.sam0"
+
 endif # COUNTER

drivers/counter/Kconfig.sam0

@@ -0,0 +1,28 @@
+# Copyright (c) 2019 Derek Hageman <[email protected]>
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+menuconfig COUNTER_SAM0_TC32
+	bool "SAM0 series 32-bit basic timer driver"
+	default y
+	depends on SOC_FAMILY_SAM0
+	help
+	  Enable the SAM0 series timer counter (TC) driver in 32-bit wide
+	  mode.
+
+if COUNTER_SAM0_TC32
+
+index = 0
+source "drivers/counter/Kconfig.template.sam0_tc32"
+
+index = 2
+source "drivers/counter/Kconfig.template.sam0_tc32"
+
+index = 4
+source "drivers/counter/Kconfig.template.sam0_tc32"
+
+index = 6
+source "drivers/counter/Kconfig.template.sam0_tc32"
+
+endif # COUNTER_SAM0_TC32

drivers/counter/Kconfig.template.sam0_tc32

@@ -0,0 +1,38 @@
+# Copyright (c) 2019 Derek Hageman <[email protected]>
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+
+choice
+	bool "Timer $(index) prescaler"
+
+	config COUNTER_SAM0_TC32_$(index)_PRESCALER_1
+		bool "clock / 1"
+	config COUNTER_SAM0_TC32_$(index)_PRESCALER_2
+		bool "clock / 2"
+	config COUNTER_SAM0_TC32_$(index)_PRESCALER_4
+		bool "clock / 4"
+	config COUNTER_SAM0_TC32_$(index)_PRESCALER_8
+		bool "clock / 8"
+	config COUNTER_SAM0_TC32_$(index)_PRESCALER_16
+		bool "clock / 16"
+	config COUNTER_SAM0_TC32_$(index)_PRESCALER_64
+		bool "clock / 64"
+	config COUNTER_SAM0_TC32_$(index)_PRESCALER_256
+		bool "clock / 256"
+	config COUNTER_SAM0_TC32_$(index)_PRESCALER_1024
+		bool "clock / 1024"
+
+endchoice
+
+config COUNTER_SAM0_TC32_$(index)_DIVISOR
+	int
+	default 1 if COUNTER_SAM0_TC32_$(index)_PRESCALER_1
+	default 2 if COUNTER_SAM0_TC32_$(index)_PRESCALER_2
+	default 4 if COUNTER_SAM0_TC32_$(index)_PRESCALER_4
+	default 8 if COUNTER_SAM0_TC32_$(index)_PRESCALER_8
+	default 16 if COUNTER_SAM0_TC32_$(index)_PRESCALER_16
+	default 64 if COUNTER_SAM0_TC32_$(index)_PRESCALER_64
+	default 256 if COUNTER_SAM0_TC32_$(index)_PRESCALER_256
+	default 1024 if COUNTER_SAM0_TC32_$(index)_PRESCALER_1024