stm32/qspi: Set pin speed to very-high and allow to config some options.

The default speed of the QSPI interface is 72Mhz whereas the standard AF
pin speed (high) is only rated to 50Mhz, so increase speed to very-high.

ports/stm32/mboot/mphalport.h

@@ -39,6 +39,10 @@
 #define MP_HAL_PIN_PULL_NONE            (GPIO_NOPULL)
 #define MP_HAL_PIN_PULL_UP              (GPIO_PULLUP)
 #define MP_HAL_PIN_PULL_DOWN            (GPIO_PULLDOWN)
+#define MP_HAL_PIN_SPEED_LOW            (GPIO_SPEED_FREQ_LOW)
+#define MP_HAL_PIN_SPEED_MEDIUM         (GPIO_SPEED_FREQ_MEDIUM)
+#define MP_HAL_PIN_SPEED_HIGH           (GPIO_SPEED_FREQ_HIGH)
+#define MP_HAL_PIN_SPEED_VERY_HIGH      (GPIO_SPEED_FREQ_VERY_HIGH)
 
 #define mp_hal_pin_obj_t        uint32_t
 #define mp_hal_pin_input(p)     mp_hal_pin_config((p), MP_HAL_PIN_MODE_INPUT, MP_HAL_PIN_PULL_NONE, 0)

ports/stm32/qspi.c

@@ -33,21 +33,37 @@
 
 #if defined(MICROPY_HW_QSPIFLASH_SIZE_BITS_LOG2)
 
+#ifndef MICROPY_HW_QSPI_PRESCALER
+#define MICROPY_HW_QSPI_PRESCALER       3  // F_CLK = F_AHB/3 (72MHz when CPU is 216MHz)
+#endif
+
+#ifndef MICROPY_HW_QSPI_SAMPLE_SHIFT
+#define MICROPY_HW_QSPI_SAMPLE_SHIFT    1  // sample shift enabled
+#endif
+
+#ifndef MICROPY_HW_QSPI_TIMEOUT_COUNTER
+#define MICROPY_HW_QSPI_TIMEOUT_COUNTER 0  // timeout counter disabled (see F7 errata)
+#endif
+
+#ifndef MICROPY_HW_QSPI_CS_HIGH_CYCLES
+#define MICROPY_HW_QSPI_CS_HIGH_CYCLES  2  // nCS stays high for 2 cycles
+#endif
+
 void qspi_init(void) {
     // Configure pins
-    mp_hal_pin_config_alt_static(MICROPY_HW_QSPIFLASH_CS, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, STATIC_AF_QUADSPI_BK1_NCS);
-    mp_hal_pin_config_alt_static(MICROPY_HW_QSPIFLASH_SCK, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, STATIC_AF_QUADSPI_CLK);
-    mp_hal_pin_config_alt_static(MICROPY_HW_QSPIFLASH_IO0, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, STATIC_AF_QUADSPI_BK1_IO0);
-    mp_hal_pin_config_alt_static(MICROPY_HW_QSPIFLASH_IO1, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, STATIC_AF_QUADSPI_BK1_IO1);
-    mp_hal_pin_config_alt_static(MICROPY_HW_QSPIFLASH_IO2, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, STATIC_AF_QUADSPI_BK1_IO2);
-    mp_hal_pin_config_alt_static(MICROPY_HW_QSPIFLASH_IO3, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, STATIC_AF_QUADSPI_BK1_IO3);
+    mp_hal_pin_config_alt_static_speed(MICROPY_HW_QSPIFLASH_CS, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, MP_HAL_PIN_SPEED_VERY_HIGH, STATIC_AF_QUADSPI_BK1_NCS);
+    mp_hal_pin_config_alt_static_speed(MICROPY_HW_QSPIFLASH_SCK, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, MP_HAL_PIN_SPEED_VERY_HIGH, STATIC_AF_QUADSPI_CLK);
+    mp_hal_pin_config_alt_static_speed(MICROPY_HW_QSPIFLASH_IO0, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, MP_HAL_PIN_SPEED_VERY_HIGH, STATIC_AF_QUADSPI_BK1_IO0);
+    mp_hal_pin_config_alt_static_speed(MICROPY_HW_QSPIFLASH_IO1, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, MP_HAL_PIN_SPEED_VERY_HIGH, STATIC_AF_QUADSPI_BK1_IO1);
+    mp_hal_pin_config_alt_static_speed(MICROPY_HW_QSPIFLASH_IO2, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, MP_HAL_PIN_SPEED_VERY_HIGH, STATIC_AF_QUADSPI_BK1_IO2);
+    mp_hal_pin_config_alt_static_speed(MICROPY_HW_QSPIFLASH_IO3, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, MP_HAL_PIN_SPEED_VERY_HIGH, STATIC_AF_QUADSPI_BK1_IO3);
 
     // Bring up the QSPI peripheral
 
     __HAL_RCC_QSPI_CLK_ENABLE();
 
     QUADSPI->CR =
-        2 << QUADSPI_CR_PRESCALER_Pos // F_CLK = F_AHB/3 (72MHz when CPU is 216MHz)
+        (MICROPY_HW_QSPI_PRESCALER - 1) << QUADSPI_CR_PRESCALER_Pos
         | 3 << QUADSPI_CR_FTHRES_Pos // 4 bytes must be available to read/write
         #if defined(QUADSPI_CR_FSEL_Pos)
         | 0 << QUADSPI_CR_FSEL_Pos // FLASH 1 selected
@@ -55,14 +71,14 @@ void qspi_init(void) {
         #if defined(QUADSPI_CR_DFM_Pos)
         | 0 << QUADSPI_CR_DFM_Pos // dual-flash mode disabled
         #endif
-        | 1 << QUADSPI_CR_SSHIFT_Pos // do sample shift
-        | 0 << QUADSPI_CR_TCEN_Pos // timeout counter disabled (see F7 errata)
+        | MICROPY_HW_QSPI_SAMPLE_SHIFT << QUADSPI_CR_SSHIFT_Pos
+        | MICROPY_HW_QSPI_TIMEOUT_COUNTER << QUADSPI_CR_TCEN_Pos
         | 1 << QUADSPI_CR_EN_Pos // enable the peripheral
         ;
 
     QUADSPI->DCR =
         (MICROPY_HW_QSPIFLASH_SIZE_BITS_LOG2 - 3 - 1) << QUADSPI_DCR_FSIZE_Pos
-        | 1 << QUADSPI_DCR_CSHT_Pos // nCS stays high for 2 cycles
+        | (MICROPY_HW_QSPI_CS_HIGH_CYCLES - 1) << QUADSPI_DCR_CSHT_Pos
         | 0 << QUADSPI_DCR_CKMODE_Pos // CLK idles at low state
         ;
 }