drivers, stm32: Support SPI/QSPI flash chips over 16MB.

With a SPI flash that has more than 16MB, 32-bit addressing is required
rather than the standard 24-bit.  This commit adds support for 32-bit
addressing so that the SPI flash commands (read/write/erase) are selected
automatically depending on the size of the address being used at each
operation.

2 files changed, 23 insertions, 4 deletions

diff --git a/drivers/bus/qspi.h b/drivers/bus/qspi.h
index 31c9d14fc..c82796fac 100644
--- a/drivers/bus/qspi.h
+++ b/drivers/bus/qspi.h
@@ -28,6 +28,8 @@
 
 #include "py/mphal.h"
 
+#define MP_SPI_ADDR_IS_32B(addr) (addr & 0xff000000)
+
 enum {
     MP_QSPI_IOCTL_INIT,
     MP_QSPI_IOCTL_DEINIT,
@@ -54,4 +56,19 @@ typedef struct _mp_soft_qspi_obj_t {
 
 extern const mp_qspi_proto_t mp_soft_qspi_proto;
 
+static inline uint8_t mp_spi_set_addr_buff(uint8_t *buf, uint32_t addr) {
+    if (MP_SPI_ADDR_IS_32B(addr)) {
+        buf[0] = addr >> 24;
+        buf[1] = addr >> 16;
+        buf[2] = addr >> 8;
+        buf[3] = addr;
+        return 4;
+    } else {
+        buf[0] = addr >> 16;
+        buf[1] = addr >> 8;
+        buf[2] = addr;
+        return 3;
+    }
+}
+
 #endif // MICROPY_INCLUDED_DRIVERS_BUS_QSPI_H
diff --git a/drivers/bus/softqspi.c b/drivers/bus/softqspi.c
index 10c599246..71ab55976 100644
--- a/drivers/bus/softqspi.c
+++ b/drivers/bus/softqspi.c
@@ -168,9 +168,10 @@ STATIC void mp_soft_qspi_write_cmd_data(void *self_in, uint8_t cmd, size_t len,
 
 STATIC void mp_soft_qspi_write_cmd_addr_data(void *self_in, uint8_t cmd, uint32_t addr, size_t len, const uint8_t *src) {
     mp_soft_qspi_obj_t *self = (mp_soft_qspi_obj_t*)self_in;
-    uint8_t cmd_buf[4] = {cmd, addr >> 16, addr >> 8, addr};
+    uint8_t cmd_buf[5] = {cmd};
+    uint8_t addr_len = mp_spi_set_addr_buff(&cmd_buf[1], addr);
     CS_LOW(self);
-    mp_soft_qspi_transfer(self, 4, cmd_buf, NULL);
+    mp_soft_qspi_transfer(self, addr_len + 1, cmd_buf, NULL);
     mp_soft_qspi_transfer(self, len, src, NULL);
     CS_HIGH(self);
 }
@@ -186,10 +187,11 @@ STATIC uint32_t mp_soft_qspi_read_cmd(void *self_in, uint8_t cmd, size_t len) {
 
 STATIC void mp_soft_qspi_read_cmd_qaddr_qdata(void *self_in, uint8_t cmd, uint32_t addr, size_t len, uint8_t *dest) {
     mp_soft_qspi_obj_t *self = (mp_soft_qspi_obj_t*)self_in;
-    uint8_t cmd_buf[7] = {cmd, addr >> 16, addr >> 8, addr};
+    uint8_t cmd_buf[7] = {cmd};
+    uint8_t addr_len = mp_spi_set_addr_buff(&cmd_buf[1], addr);
     CS_LOW(self);
     mp_soft_qspi_transfer(self, 1, cmd_buf, NULL);
-    mp_soft_qspi_qwrite(self, 6, &cmd_buf[1]); // 3 addr bytes, 1 extra byte (0), 2 dummy bytes (4 dummy cycles)
+    mp_soft_qspi_qwrite(self, addr_len + 3, &cmd_buf[1]); // 3/4 addr bytes, 1 extra byte (0), 2 dummy bytes (4 dummy cycles)
     mp_soft_qspi_qread(self, len, dest);
     CS_HIGH(self);
 }