Merge branch 'feature/dport_access' into 'master'

soc: Dport access with pre-read register APB See merge request idf/esp-idf!2257
2025-08-26 18:14:11 +00:00 · 2018-05-15 15:32:28 +08:00
parent 0ae6a83768 8f80cc733d
commit d1066e9d7f
8 changed files with 467 additions and 158 deletions
--- a/components/soc/esp32/include/soc/dport_access.h
+++ b/components/soc/esp32/include/soc/dport_access.h
@@ -18,6 +18,9 @@
 #include <stdint.h>
 #include "esp_attr.h"
 #include "esp_dport_access.h"
+#include "soc.h"
+#include "uart_reg.h"
+#include "xtensa/xtruntime.h"

 #ifdef __cplusplus
 extern "C" {
@@ -28,10 +31,29 @@ extern "C" {
 // The _DPORT_xxx register read macros access DPORT memory directly (as opposed to
 // DPORT_REG_READ which applies SMP-safe protections).
 //
-// Use DPORT_REG_READ versions to be SMP-safe in IDF apps. If you want to
-// make a sequence of DPORT reads, use DPORT_STALL_OTHER_CPU_START() macro
-// explicitly and then use _DPORT_REG_READ macro while other CPU is stalled.
-//
+// There are several ways to read the DPORT registers:
+// 1) Use DPORT_REG_READ versions to be SMP-safe in IDF apps.
+//    This method uses the pre-read APB implementation(*) without stall other CPU.
+//    This is beneficial for single readings.
+// 2) If you want to make a sequence of DPORT reads to buffer,
+//    use dport_read_buffer(buff_out, address, num_words),
+//    it is the faster method and it doesn't stop other CPU.
+// 3) If you want to make a sequence of DPORT reads, but you don't want to stop other CPU
+//    and you want to do it faster then you need use DPORT_SEQUENCE_REG_READ().
+//    The difference from the first is that the user himself must disable interrupts while DPORT reading.
+//    Note that disable interrupt need only if the chip has two cores.
+// 4) If you want to make a sequence of DPORT reads,
+//    use DPORT_STALL_OTHER_CPU_START() macro explicitly
+//    and then use _DPORT_REG_READ macro while other CPU is stalled.
+//    After completing read operations, use DPORT_STALL_OTHER_CPU_END().
+//    This method uses stall other CPU while reading DPORT registers.
+//    Useful for compatibility, as well as for large consecutive readings.
+//    This method is slower, but must be used if ROM functions or 
+//    other code is called which accesses DPORT without any other workaround.
+// *) The pre-readable APB register before reading the DPORT register
+//    helps synchronize the operation of the two CPUs,
+//    so that reading on different CPUs no longer causes random errors APB register.
+
 // _DPORT_REG_WRITE & DPORT_REG_WRITE are equivalent.
 #define _DPORT_REG_READ(_r)        (*(volatile uint32_t *)(_r))
 #define _DPORT_REG_WRITE(_r, _v)   (*(volatile uint32_t *)(_r)) = (_v)
@@ -39,16 +61,78 @@ extern "C" {
 // Write value to DPORT register (does not require protecting)
 #define DPORT_REG_WRITE(_r, _v)   _DPORT_REG_WRITE((_r), (_v))

-// Read value from register, SMP-safe version.
+/**
+ * @brief Read value from register, SMP-safe version.
+ *
+ * This method uses the pre-reading of the APB register before reading the register of the DPORT.
+ * This implementation is useful for reading DORT registers for single reading without stall other CPU.
+ * There is disable/enable interrupt.
+ *
+ * @param reg Register address
+ * @return Value
+ */
 static inline uint32_t IRAM_ATTR DPORT_REG_READ(uint32_t reg)
 {
-    uint32_t val;
+#ifndef CONFIG_FREERTOS_UNICORE
+    uint32_t apb;
+    unsigned int intLvl;
+    __asm__ __volatile__ (\
+                  "movi %[APB], "XTSTR(0x3ff40078)"\n"\
+                  "rsil %[LVL], "XTSTR(3)"\n"\
+                  "l32i %[APB], %[APB], 0\n"\
+                  "l32i %[REG], %[REG], 0\n"\
+                  "wsr  %[LVL], "XTSTR(PS)"\n"\
+                  "rsync\n"\
+                  : [APB]"=a"(apb), [REG]"+a"(reg), [LVL]"=a"(intLvl)\
+                  : \
+                  : "memory" \
+                  );
+    return reg;
+#else
+    return _DPORT_REG_READ(reg);
+#endif
+}

-    DPORT_STALL_OTHER_CPU_START();
-    val = _DPORT_REG_READ(reg);
-    DPORT_STALL_OTHER_CPU_END();
-
-    return val;
+/**
+ * @brief Read value from register, NOT SMP-safe version.
+ *
+ * This method uses the pre-reading of the APB register before reading the register of the DPORT.
+ * There is not disable/enable interrupt.
+ * The difference from DPORT_REG_READ() is that the user himself must disable interrupts while DPORT reading.
+ * This implementation is useful for reading DORT registers in loop without stall other CPU. Note the usage example.
+ * The recommended way to read registers sequentially without stall other CPU
+ * is to use the method esp_dport_read_buffer(buff_out, address, num_words). It allows you to read registers in the buffer.
+ *
+ * \code{c}
+ * // This example shows how to use it.
+ * { // Use curly brackets to limit the visibility of variables in macros DPORT_INTERRUPT_DISABLE/RESTORE.
+ *     DPORT_INTERRUPT_DISABLE(); // Disable interrupt only on current CPU.
+ *     for (i = 0; i < max; ++i) {
+ *        array[i] = DPORT_SEQUENCE_REG_READ(Address + i * 4); // reading DPORT registers
+ *     }
+ *     DPORT_INTERRUPT_RESTORE(); // restore the previous interrupt level
+ * }
+ * \endcode
+ *
+ * @param reg Register address
+ * @return Value
+ */
+static inline uint32_t IRAM_ATTR DPORT_SEQUENCE_REG_READ(uint32_t reg)
+{
+#ifndef CONFIG_FREERTOS_UNICORE
+    uint32_t apb;
+    __asm__ __volatile__ (\
+                  "movi %[APB], "XTSTR(0x3ff40078)"\n"\
+                  "l32i %[APB], %[APB], 0\n"\
+                  "l32i %[REG], %[REG], 0\n"\
+                  : [APB]"=a"(apb), [REG]"+a"(reg)\
+                  : \
+                  : "memory" \
+                  );
+    return reg;
+#else
+    return _DPORT_REG_READ(reg);
+#endif
 }

 //get bit or get bits from register
@@ -93,16 +177,35 @@ static inline uint32_t IRAM_ATTR DPORT_REG_READ(uint32_t reg)
 #define _DPORT_REG_SET_BIT(_r, _b)  _DPORT_REG_WRITE((_r), (_DPORT_REG_READ(_r)|(_b)))
 #define _DPORT_REG_CLR_BIT(_r, _b)  _DPORT_REG_WRITE((_r), (_DPORT_REG_READ(_r) & (~(_b))))

-//read value from register
-static inline uint32_t IRAM_ATTR DPORT_READ_PERI_REG(uint32_t addr) 
+/**
+ * @brief Read value from register, SMP-safe version.
+ *
+ * This method uses the pre-reading of the APB register before reading the register of the DPORT.
+ * This implementation is useful for reading DORT registers for single reading without stall other CPU.
+ *
+ * @param reg Register address
+ * @return Value
+ */
+static inline uint32_t IRAM_ATTR DPORT_READ_PERI_REG(uint32_t reg)
 {
-    uint32_t val;
-
-    DPORT_STALL_OTHER_CPU_START();
-    val = _DPORT_READ_PERI_REG(addr);
-    DPORT_STALL_OTHER_CPU_END();
-    
-    return val;
+#ifndef CONFIG_FREERTOS_UNICORE
+    uint32_t apb;
+    unsigned int intLvl;
+    __asm__ __volatile__ (\
+                  "movi %[APB], "XTSTR(0x3ff40078)"\n"\
+                  "rsil %[LVL], "XTSTR(3)"\n"\
+                  "l32i %[APB], %[APB], 0\n"\
+                  "l32i %[REG], %[REG], 0\n"\
+                  "wsr  %[LVL], "XTSTR(PS)"\n"\
+                  "rsync\n"\
+                  : [APB]"=a"(apb), [REG]"+a"(reg), [LVL]"=a"(intLvl)\
+                  : \
+                  : "memory" \
+                  );
+    return reg;
+#else
+    return _DPORT_READ_PERI_REG(reg);
+#endif
 }

 //write value to register