stm32f7: Add basic PWM support to nucleo-144 board

More PWMs and multi channels support
may be investigated and added later.

It was tested on nucleo-f767zi
with those features enabled in configuration:

```
CONFIG_EXAMPLES_PWM=y
CONFIG_PWM=y
CONFIG_STM32F7_TIM1=y
CONFIG_STM32F7_TIM1_PWM=y
CONFIG_STM32F7_TIM2=y
(...)
CONFIG_STM32F7_TIM4_PWM=y
```

Change-Id: I08ebd4a538d15661788a0a54c2113ad767f22747
Bug: https://bitbucket.org/nuttx/nuttx/issues/153
Relate-to: rzr/webthing-iotjs#3
Forwarded: https://bitbucket.org/nuttx/nuttx/pull-requests/862
Signed-off-by: Philippe Coval <p.coval@samsung.com>

configs/nucleo-144/include/board.h

@@ -348,6 +348,12 @@
 
 /* Alternate function pin selections ************************************************/
 
+/* TIM */
+#define GPIO_TIM1_CH1OUT GPIO_TIM1_CH1OUT_1
+#define GPIO_TIM2_CH1OUT GPIO_TIM2_CH1OUT_1
+#define GPIO_TIM3_CH1OUT GPIO_TIM3_CH1OUT_1
+#define GPIO_TIM4_CH1OUT GPIO_TIM4_CH1OUT_1
+
 #if defined(CONFIG_NUCLEO_CONSOLE_ARDUINO)
 /* USART6:
  *

configs/nucleo-144/src/Makefile

@@ -61,6 +61,10 @@ ifeq ($(CONFIG_ADC),y)
 CSRCS += stm32_adc.c
 endif
 
+ifeq ($(CONFIG_PWM),y)
+CSRCS += stm32_pwm.c
+endif
+
 ifeq ($(CONFIG_MMCSD),y)
 CSRCS += stm32_sdio.c
 endif

configs/nucleo-144/src/nucleo-144.h

@@ -255,6 +255,18 @@ int stm32_sdio_initialize(void);
 void stm32_usbinitialize(void);
 #endif
 
+/************************************************************************************
+ * Name: stm32_pwm_setup
+ *
+ * Description:
+ *   Initialize PWM and register the PWM device.
+ *
+ ************************************************************************************/
+
+#ifdef CONFIG_PWM
+int stm32_pwm_setup(void);
+#endif
+
 /************************************************************************************
  * Name: stm32_adc_setup
  *

configs/nucleo-144/src/stm32_appinitialize.c

@@ -149,6 +149,16 @@ int board_app_initialize(uintptr_t arg)
     }
 #endif
 
+#if defined(CONFIG_PWM)
+  /* Initialize PWM and register the PWM device */
+
+  ret = stm32_pwm_setup();
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: stm32_pwm_setup() failed: %d\n", ret);
+    }
+#endif
+
   UNUSED(ret);
   return OK;
 }

configs/nucleo-144/src/stm32_pwm.c

@@ -0,0 +1,162 @@
+/************************************************************************************
+ * configs/nucleo-144/src/stm32_pwm.c
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *   Author: Philippe Coval <p.coval@samsung.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ************************************************************************************/
+
+/************************************************************************************
+ * Included Files
+ ************************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <errno.h>
+#include <debug.h>
+#include <sys/types.h>
+
+#include <nuttx/board.h>
+#include <nuttx/drivers/pwm.h>
+#include <arch/board/board.h>
+
+#include "chip.h"
+#include "up_arch.h"
+#include "stm32_pwm.h"
+#include "nucleo-144.h"
+
+/************************************************************************************
+ * Pre-processor Definitions
+ ************************************************************************************/
+
+#define HAVE_PWM 1
+#ifndef CONFIG_PWM
+#  undef HAVE_PWM
+#endif
+
+/************************************************************************************
+ * Public Functions
+ ************************************************************************************/
+
+/************************************************************************************
+ * Name: stm32_pwm_setup
+ *
+ * Description:
+ *   Initialize PWM and register the PWM device.
+ *
+ ************************************************************************************/
+
+int stm32_pwm_setup(void)
+{
+#ifdef HAVE_PWM
+  static bool initialized = false;
+  struct pwm_lowerhalf_s *pwm;
+  int ret;
+
+  /* Have we already initialized? */
+
+  if (!initialized)
+    {
+      /* Call stm32_pwminitialize() to get an instance of the PWM interface */
+
+#if defined(CONFIG_STM32F7_TIM1_PWM)
+      pwm = stm32_pwminitialize(1);
+      if (!pwm)
+        {
+          aerr("ERROR: Failed to get the STM32F7 PWM lower half\n");
+          return -ENODEV;
+        }
+
+      ret = pwm_register("/dev/pwm0", pwm);
+      if (ret < 0)
+        {
+          aerr("ERROR: pwm_register failed: %d\n", ret);
+          return ret;
+        }
+#endif
+
+#if defined(CONFIG_STM32F7_TIM2_PWM)
+      pwm = stm32_pwminitialize(2);
+      if (!pwm)
+        {
+          aerr("ERROR: Failed to get the STM32F7 PWM lower half\n");
+          return -ENODEV;
+        }
+
+      ret = pwm_register("/dev/pwm1", pwm);
+      if (ret < 0)
+        {
+          aerr("ERROR: pwm_register failed: %d\n", ret);
+          return ret;
+        }
+#endif
+
+#if defined(CONFIG_STM32F7_TIM3_PWM)
+      pwm = stm32_pwminitialize(3);
+      if (!pwm)
+        {
+          aerr("ERROR: Failed to get the STM32F7 PWM lower half\n");
+          return -ENODEV;
+        }
+
+      ret = pwm_register("/dev/pwm2", pwm);
+      if (ret < 0)
+        {
+          aerr("ERROR: pwm_register failed: %d\n", ret);
+          return ret;
+        }
+#endif
+
+#if defined(CONFIG_STM32F7_TIM4_PWM)
+      pwm = stm32_pwminitialize(4);
+      if (!pwm)
+        {
+          aerr("ERROR: Failed to get the STM32F7 PWM lower half\n");
+          return -ENODEV;
+        }
+
+      ret = pwm_register("/dev/pwm3", pwm);
+      if (ret < 0)
+        {
+          aerr("ERROR: pwm_register failed: %d\n", ret);
+          return ret;
+        }
+#endif
+      /* Now we are initialized */
+
+      initialized = true;
+    }
+
+  return OK;
+#else
+  return -ENODEV;
+#endif
+}