samv7/sam_chipid: add sam_has_revb_periphs function

This function can identify (during the runtime) whether the chip
is revB or revA. Bear in mind PIC32CZ2051CA70 is always revB.
Allows to have one binary compatible with SAMV7 and PIC32.

Thanks to Pavel Pisa and Michal Lenc for the suggested code.

Signed-off-by: Stepan Pressl <pressl.stepan@gmail.com>

arch/arm/src/samv7/Make.defs

@@ -31,7 +31,7 @@ include armv7-m/Make.defs
 
 CHIP_CSRCS  = sam_start.c sam_clockconfig.c sam_irq.c sam_allocateheap.c
 CHIP_CSRCS += sam_lowputc.c sam_serial.c sam_gpio.c sam_pck.c sam_uid.c
-CHIP_CSRCS += sam_systemreset.c
+CHIP_CSRCS += sam_systemreset.c sam_chipid.c
 
 # Configuration-dependent SAMV7 files
 

arch/arm/src/samv7/sam_chipid.c

@@ -0,0 +1,62 @@
+/****************************************************************************
+ * arch/arm/src/samv7/sam_chipid.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include "sam_chipid.h"
+#include "hardware/sam_chipid.h"
+#include "arm_internal.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+bool sam_has_revb_periphs(void)
+{
+#ifdef CONFIG_ARCH_CHIP_PIC32CZCA70
+  return true;
+#else
+  /* If not built for PIC32CZ, decide which chip is being used */
+
+  uint32_t regval;
+  uint32_t id_arch;
+  uint32_t id_version;
+
+  regval = getreg32(SAM_CHIPID_CIDR);
+  id_arch = (regval & CHIPID_CIDR_ARCH_MASK) >> CHIPID_CIDR_ARCH_SHIFT;
+  id_version = (regval & CHIPID_CIDR_VERSION_MASK)
+                >> CHIPID_CIDR_VERSION_SHIFT;
+
+  /* SAMV7s are identified by 0x10-0x13, therefore
+   * anything else should be PIC32
+   */
+
+  if ((id_arch & ~3) != 0x10)
+    {
+      return true;
+    }
+
+  return id_version != 0;
+#endif /* CONFIG_ARCH_CHIP_PIC32CZCA70 */
+}

arch/arm/src/samv7/sam_chipid.h

@@ -0,0 +1,65 @@
+/****************************************************************************
+ * arch/arm/src/samv7/sam_chipid.h
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_ARM_SRC_SAMV7_SAM_CHIPID_H
+#define __ARCH_ARM_SRC_SAMV7_SAM_CHIPID_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <stdbool.h>
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: sam_has_revb_periphs
+ *
+ * Description:
+ *   Returns true if revA peripherals are used, false otherwise.
+ *.  Note: PIC32CZ CA70 are always revB.
+ *
+ ****************************************************************************/
+
+bool sam_has_revb_periphs(void);
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __ARCH_ARM_SRC_SAMV7_SAM_CHIPID_H */