From b533fcf5431bbefbb2ffedcc6a0dfc35a595a9bc Mon Sep 17 00:00:00 2001
From: Marian Buschsieweke <marian.buschsieweke@ovgu.de>
Date: Tue, 22 Nov 2022 13:43:05 +0100
Subject: [PATCH] cpu/nrf5x_common: improve doc on timer_conf_t::channels

---
 cpu/nrf5x_common/include/periph_cpu_common.h | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/cpu/nrf5x_common/include/periph_cpu_common.h b/cpu/nrf5x_common/include/periph_cpu_common.h
index 7e43a7dd09..c6fa1cfc4e 100644
--- a/cpu/nrf5x_common/include/periph_cpu_common.h
+++ b/cpu/nrf5x_common/include/periph_cpu_common.h
@@ -187,7 +187,14 @@ typedef enum {
  */
 typedef struct {
     NRF_TIMER_Type *dev;    /**< timer device */
-    uint8_t channels;       /**< number of channels available */
+    /**
+     * @brief   number of hardware channels ***minus one***
+     *
+     * The last hardware channels is implicitly used by timer_read() and not
+     * available to the user. This value, hence, is the number of channels
+     * available to the user.
+     */
+    uint8_t channels;
     uint8_t bitmode;        /**< counter width */
     uint8_t irqn;           /**< IRQ number of the timer device */
 } timer_conf_t;