From 7430b92d27c912cf2e43337b4c4a45dac73100b0 Mon Sep 17 00:00:00 2001
From: jun2sak <j.2.sakai@gmail.com>
Date: Sun, 7 Mar 2021 20:20:29 +0900
Subject: [PATCH] address hw pin-reset while sleep.

---
 ports/nrf/supervisor/qspi_flash.c | 49 ++++++++++++++++++-------------
 1 file changed, 28 insertions(+), 21 deletions(-)

diff --git a/ports/nrf/supervisor/qspi_flash.c b/ports/nrf/supervisor/qspi_flash.c
index 00a88d52b9..d2bf9678da 100644
--- a/ports/nrf/supervisor/qspi_flash.c
+++ b/ports/nrf/supervisor/qspi_flash.c
@@ -41,6 +41,27 @@
 #include "supervisor/serial.h" // dbg_printf()
 #endif
 
+#ifdef QSPI_FLASH_POWERDOWN
+// Parameters for external QSPI Flash power-down
+// for W25Q128FV,
+//   tDP (nCS high to Power-down mode) = 3us
+//   tRES (nCS high to Standby mode)   = 3us
+//   sck_delay = max(tDP, tRES) / 62.5ns = 48  -> 50 (w/ margin)
+#define DUR_DPM_ENTER  1  // tDP  in (256*62.5ns) units
+#define DUR_DPM_EXIT   1  // tRES in (256*62.5ns) units
+#define SCK_DELAY      50 // max(tDP, tRES) in (62.5ns) units
+//   wait necessary just after DPM enter/exit (cut and try)
+#define WAIT_AFTER_DPM_ENTER 10 // usec
+#define WAIT_AFTER_DPM_EXIT  50 // usec
+#endif
+
+static int sck_delay_saved = 0;
+#ifdef NRF_DEBUG_PRINT
+extern void dbg_dumpQSPIreg(void);
+#else
+#define dbg_dumpQSPIreg(...)
+#endif
+
 // When USB is disconnected, disable QSPI in sleep mode to save energy
 void qspi_disable(void)
 {
@@ -222,6 +243,13 @@ void spi_flash_init(void) {
 
     // No callback for blocking API
     nrfx_qspi_init(&qspi_cfg, NULL, NULL);
+
+#ifdef QSPI_FLASH_POWERDOWN
+    // If pin-reset while flash is in power-down mode,
+    // the flash cannot accept any commands. Send CMD_WAKE to release it.
+    spi_flash_write_command(CMD_WAKE, NULL, 0);
+    NRFX_DELAY_US(WAIT_AFTER_DPM_EXIT);
+#endif
 }
 
 void spi_flash_init_device(const external_flash_device* device) {
@@ -246,27 +274,6 @@ void spi_flash_init_device(const external_flash_device* device) {
     NRF_QSPI->IFCONFIG1 |=  sckfreq << QSPI_IFCONFIG1_SCKFREQ_Pos;
 }
 
-#ifdef QSPI_FLASH_POWERDOWN
-// Parameters for external QSPI Flash power-down
-// for W25Q128FV,
-//   tDP (nCS high to Power-down mode) = 3us
-//   tRES (nCS high to Standby mode)   = 3us
-//   sck_delay = max(tDP, tRES) / 62.5ns = 48  -> 50 (w/ margin)
-#define DUR_DPM_ENTER  1  // tDP  in (256*62.5ns) units
-#define DUR_DPM_EXIT   1  // tRES in (256*62.5ns) units
-#define SCK_DELAY      50 // max(tDP, tRES) in (62.5ns) units
-//   wait necessary just after DPM enter/exit (cut and try)
-#define WAIT_AFTER_DPM_ENTER 10 // usec
-#define WAIT_AFTER_DPM_EXIT  50 // usec
-#endif
-
-static int sck_delay_saved = 0;
-#ifdef NRF_DEBUG_PRINT
-extern void dbg_dumpQSPIreg(void);
-#else
-#define dbg_dumpQSPIreg(...)
-#endif
-
 void qspi_flash_enter_sleep(void) {
 #ifdef QSPI_FLASH_POWERDOWN
     uint32_t r;