Merge pull request #15557 from iosabi/qn908x_ctimer

cpu/qn908x: Add timer driver based on CTIMER.

boards/qn9080dk/Kconfig

@@ -17,6 +17,7 @@ config BOARD_QN9080DK
     # Put defined MCU peripherals here (in alphabetical order)
     select BOARD_HAS_XTAL32K
     select BOARD_HAS_XTAL_32M
+    select HAS_PERIPH_TIMER
     select HAS_PERIPH_UART
     select HAS_PERIPH_UART_MODECFG
 

boards/qn9080dk/Makefile.features

@@ -3,6 +3,7 @@ CPU_MODEL = qn9080xhn
 
 # Put defined MCU peripherals here (in alphabetical order)
 FEATURES_PROVIDED += periph_gpio periph_gpio_irq
+FEATURES_PROVIDED += periph_timer
 FEATURES_PROVIDED += periph_uart periph_uart_modecfg
 
 # Include the common qn908x board features.

boards/qn9080dk/include/periph_conf.h

@@ -43,9 +43,15 @@ static const uart_conf_t uart_config[] = {
 #define UART_NUMOF          ARRAY_SIZE(uart_config)
 /** @} */
 
+/**
+ * @name   Timer configuration
+ * @{
+ */
+#define TIMER_NUMOF           4
+/** @} */
+
 /* put here the board peripherals definitions:
    - Available clocks
-   - Timers
    - PWMs
    - SPIs
    - I2C

cpu/qn908x/doc.txt

@@ -31,6 +31,25 @@ The GPIO driver uses the @ref GPIO_PIN(port, pin) macro to declare pins.
 No configuration is necessary.
 
 
+@defgroup    cpu_qn908x_timer NXP QN908x Standard counter/timers (CTIMER)
+@ingroup     cpu_qn908x
+@brief       NXP QN908x timer driver
+
+The QN908x have 4 standard counter/timers (CTIMER). These timers allow to count
+clock cycles from the APB clock with a 32-bit prescaler, effectively dividing
+the APB clock frequency by a configurable number up to 2^32, allowing a great
+range of timer frequencies selected at runtime. Each timer has 4 independent
+channels to match against which can generate an interrupt.
+
+TODO: These CTIMERs and the SCT timers can both be used as PWM as well, with
+different set of capabilities. Boards should be able to split these CTIMER and
+SCT blocks between pwm and timer functions.
+
+### Timer configuration example (for periph_conf.h) ###
+
+    #define TIMER_NUMOF           4
+
+
 @defgroup    cpu_qn908x_uart NXP QN908x UART
 @ingroup     cpu_qn908x
 @brief       NXP QN908x UART driver

cpu/qn908x/include/periph_cpu.h

@@ -81,9 +81,9 @@ typedef uint16_t gpio_t;
  * clocks installed on the board. Figure out a way to configure this limit based
  * on the clock used.
  */
-#define NWDT_TIME_LOWER_LIMIT (0)
+#define NWDT_TIME_LOWER_LIMIT (1U)
 #define NWDT_TIME_UPPER_LIMIT (268435U)
-#define WWDT_TIME_LOWER_LIMIT (0)
+#define WWDT_TIME_LOWER_LIMIT (1U)
 #define WWDT_TIME_UPPER_LIMIT (268435U)
 /** @} */
 
@@ -127,6 +127,7 @@ typedef enum {
     GPIO_HIGH       = 1,    /**< emit interrupt when the value is high */
     GPIO_RISING     = 2,    /**< emit interrupt on rising flank */
     GPIO_FALLING    = 3,    /**< emit interrupt on falling flank */
+    GPIO_BOTH       = 4,    /**< not supported -- rising and falling flanks */
 } gpio_flank_t;
 /** @} */
 #endif /* ndef DOXYGEN */
@@ -140,6 +141,14 @@ enum {
     GPIO_PORTS_NUMOF        /**< overall number of available ports */
 };
 
+/**
+ * @brief   CPU specific timer Counter/Timers (CTIMER) configuration
+ * @{
+ */
+#define TIMER_CHANNELS      (4)
+#define TIMER_MAX_VALUE     (0xffffffff)
+/** @} */
+
 /**
  * @brief UART module configuration options
  *
@@ -153,6 +162,13 @@ typedef struct {
     gpio_t tx_pin;      /**< TX pin, GPIO_UNDEF disables TX. */
 } uart_conf_t;
 
+/**
+ * @brief   Invalid UART mode mask
+ *
+ * Signals that the mode is invalid or not supported by the CPU.
+ */
+#define UART_INVALID_MODE   (0x80)
+
 /**
  * @brief   Definition of possible parity modes
  *
@@ -161,9 +177,11 @@ typedef struct {
  * @{
  */
 typedef enum {
-    UART_PARITY_NONE    = 0,    /**< no parity */
-    UART_PARITY_EVEN    = 2,    /**< even parity */
-    UART_PARITY_ODD     = 3,    /**< odd parity */
+    UART_PARITY_NONE = 0,                         /**< no parity */
+    UART_PARITY_EVEN = 2,                         /**< even parity */
+    UART_PARITY_ODD = 3,                          /**< odd parity */
+    UART_PARITY_MARK = 0x10 | UART_INVALID_MODE,  /**< mark parity */
+    UART_PARITY_SPACE = 0x20 | UART_INVALID_MODE, /**< space parity */
 } uart_parity_t;
 #define HAVE_UART_PARITY_T
 /** @} */
@@ -175,8 +193,10 @@ typedef enum {
  * @{
  */
 typedef enum {
-    UART_DATA_BITS_7    = 0,    /**< 7 data bits */
-    UART_DATA_BITS_8    = 1,    /**< 8 data bits */
+    UART_DATA_BITS_5 = 0x10 | UART_INVALID_MODE, /**< 5 data bits */
+    UART_DATA_BITS_6 = 0x20 | UART_INVALID_MODE, /**< 6 data bits */
+    UART_DATA_BITS_7 = 0,                        /**< 7 data bits */
+    UART_DATA_BITS_8 = 1,                        /**< 8 data bits */
     /* Note: There's a UART_DATA_BITS_9 possible in this hardware. */
 } uart_data_bits_t;
 #define HAVE_UART_DATA_BITS_T

cpu/qn908x/periph/gpio.c

@@ -122,6 +122,10 @@ static gpio_isr_cb_state_t gpio_isr_state[TOTAL_GPIO_PINS] = {};
 int gpio_init_int(gpio_t pin, gpio_mode_t mode, gpio_flank_t flank,
                   gpio_cb_t cb, void *arg)
 {
+    if (flank == GPIO_BOTH) {
+        /* GPIO_BOTH is not supported. */
+        return -1;
+    }
     uint8_t gpio_num = GPIO_T_PORT(pin) * PINS_PER_PORT + GPIO_T_PIN(pin);
 
     if (gpio_num >= TOTAL_GPIO_PINS) {
@@ -154,6 +158,9 @@ int gpio_init_int(gpio_t pin, gpio_mode_t mode, gpio_flank_t flank,
             base->INTTYPESET = mask;    /* SET = edge */
             base->INTPOLSET = mask;     /* SET = rising */
             break;
+        case GPIO_BOTH:
+            /* Handled above */
+            break;
     }
     gpio_irq_enable(pin);
     return 0;

cpu/qn908x/periph/timer.c

@@ -0,0 +1,174 @@
+/*
+ * Copyright (C) 2020 iosabi
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License v2.1. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+/**
+ * @ingroup     cpu_qn908x
+ * @ingroup     drivers_periph_timer
+ *
+ * @{
+ *
+ * @file
+ * @brief       Low-level timer driver implementation
+ *
+ * This driver leverages the Freescale/NXP implementation distributed with the
+ * SDK.
+ *
+ * @author      iosabi <iosabi@protonmail.com>
+ *
+ * @}
+ */
+
+#include <stdlib.h>
+
+#include "cpu.h"
+#include "board.h"
+#include "periph_conf.h"
+#include "periph/timer.h"
+
+#include "vendor/drivers/fsl_clock.h"
+
+#define ENABLE_DEBUG (0)
+#include "debug.h"
+
+/**
+ * @brief   Interrupt context information for configured timers.
+ */
+static timer_isr_ctx_t isr_ctx[FSL_FEATURE_SOC_CTIMER_COUNT];
+
+/**
+ * @brief   CTIMER peripheral base pointers.
+ */
+static CTIMER_Type* const ctimers[FSL_FEATURE_SOC_CTIMER_COUNT] =
+    CTIMER_BASE_PTRS;
+
+/**
+ * @brief   CTIMER IRQ numbers.
+ */
+static IRQn_Type const ctimers_irqn[FSL_FEATURE_SOC_CTIMER_COUNT] =
+    CTIMER_IRQS;
+
+/**
+ * @brief   CTIMER Clocks.
+ */
+static const clock_ip_name_t ctimers_clocks[FSL_FEATURE_SOC_CTIMER_COUNT] =
+    CTIMER_CLOCKS;
+
+
+/**
+ * @brief   Check the board config to make sure we do not exceed max number of
+ *          timers
+ */
+#if TIMER_NUMOF > FSL_FEATURE_SOC_CTIMER_COUNT
+#error "ERROR in board timer configuration: too many timers defined"
+#endif
+
+int timer_init(tim_t tim, unsigned long freq, timer_cb_t cb, void *arg)
+{
+    DEBUG("timer_init(%u, %lu)\n", tim, freq);
+    if (tim >= TIMER_NUMOF) {
+        return -1;
+    }
+
+    isr_ctx[tim].cb = cb;
+    isr_ctx[tim].arg = arg;
+
+    CLOCK_EnableClock(ctimers_clocks[tim]);
+
+    CTIMER_Type *dev = ctimers[tim];
+
+    /* CTIMER blocks are driven from the APB clock. */
+    uint32_t core_freq = CLOCK_GetFreq(kCLOCK_ApbClk);
+    uint32_t prescale = (core_freq + freq / 2) / freq - 1;
+    if (prescale == (uint32_t)(-1)) {
+        DEBUG("timer_init: Frequency %lu is too fast for core_freq=%lu",
+              freq, core_freq);
+        return -1;
+    }
+
+    dev->CTCR = CTIMER_CTCR_CTMODE(0); /* timer mode */
+    dev->PR = CTIMER_PR_PRVAL(prescale);
+    /* Enable timer interrupts in the NVIC. */
+    NVIC_EnableIRQ(ctimers_irqn[tim]);
+
+    /* Timer should be started after init. */
+    dev->TCR |= CTIMER_TCR_CEN_MASK;
+    return 0;
+}
+
+int timer_set_absolute(tim_t tim, int channel, unsigned int value)
+{
+    DEBUG("timer_set_absolute(%u, %u, %u)\n", tim, channel, value);
+    if ((tim >= TIMER_NUMOF) || (channel >= TIMER_CHANNELS)) {
+        return -1;
+    }
+    CTIMER_Type* const dev = ctimers[tim];
+    dev->MR[channel] = value;
+    dev->MCR |= (CTIMER_MCR_MR0I_MASK << (channel * 3));
+    return 0;
+}
+
+int timer_clear(tim_t tim, int channel)
+{
+    DEBUG("timer_clear(%u, %d)\n", tim, channel);
+    if ((tim >= TIMER_NUMOF) || (channel >= TIMER_CHANNELS)) {
+        return -1;
+    }
+    CTIMER_Type* const dev = ctimers[tim];
+    dev->MCR &= ~(CTIMER_MCR_MR0I_MASK << (channel * 3));
+    return 0;
+}
+
+unsigned int timer_read(tim_t tim)
+{
+    DEBUG("timer_read(%u) --> %" PRIu32 "\n", tim, ctimers[tim]->TC);
+    return ctimers[tim]->TC;
+}
+
+void timer_start(tim_t tim)
+{
+    DEBUG("timer_start(%u)\n", tim);
+    ctimers[tim]->TCR |= CTIMER_TCR_CEN_MASK;
+}
+
+void timer_stop(tim_t tim)
+{
+    DEBUG("timer_stop(%u)\n", tim);
+    ctimers[tim]->TCR &= ~CTIMER_TCR_CEN_MASK;
+}
+
+static inline void isr_ctimer_n(CTIMER_Type *dev, uint32_t ctimer_num)
+{
+    DEBUG("isr_ctimer_%" PRIu32 " flags=0x%" PRIx32 "\n",
+          ctimer_num, dev->IR);
+    for (uint32_t i = 0; i < TIMER_CHANNELS; i++) {
+        if (dev->IR & (1u << i)) {
+            /* Note: setting the bit to 1 in the flag register will clear the
+             * bit. */
+            dev->IR = 1u << i;
+            dev->MCR &= ~(CTIMER_MCR_MR0I_MASK << (i * 3));
+            isr_ctx[ctimer_num].cb(isr_ctx[ctimer_num].arg, 0);
+        }
+    }
+    cortexm_isr_end();
+}
+
+#ifdef CTIMER0
+void isr_ctimer0(void) { isr_ctimer_n(CTIMER0, 0); }
+#endif /* CTIMER0 */
+
+#ifdef CTIMER1
+void isr_ctimer1(void) { isr_ctimer_n(CTIMER1, 1); }
+#endif /* CTIMER1 */
+
+#ifdef CTIMER2
+void isr_ctimer2(void) { isr_ctimer_n(CTIMER2, 2); }
+#endif /* CTIMER2 */
+
+#ifdef CTIMER3
+void isr_ctimer3(void) { isr_ctimer_n(CTIMER3, 3); }
+#endif /* CTIMER3 */

cpu/qn908x/periph/uart.c

@@ -223,6 +223,9 @@ int uart_init(uart_t uart, uint32_t baudrate, uart_rx_cb_t rx_cb, void *arg)
 int uart_mode(uart_t uart, uart_data_bits_t data_bits, uart_parity_t parity,
               uart_stop_bits_t stop_bits)
 {
+    if ((data_bits & UART_INVALID_MODE) || (parity & UART_INVALID_MODE)) {
+        return UART_NOMODE;
+    }
     /* Setup mode and enable USART. The values of the uart_data_bits_t,
      * uart_parity_t and uart_stop_bits_t enums were selected to match the
      * fields in this registers so there's no need to do any conversion. */