stm32/qspi.c: Allow qspi_write_cmd_data to write cmd with 1 data byte.

victorallume · victorallume · commit 59824a6a49dc · 2023-07-04T15:35:00.000+10:00
The existing qspi for stm32 implementation can only send a spi command with
exactly 0 or 2 data bytes. Certain spiflash chips (e.g. AT25SF321B) have
commands that only take a single data byte, and will ignore the command if
more than that is sent. This allows sending a command with a single data
byte. Would be nicer to have a general function to send `n` bytes, but
there probably aren't many commands that require this.
diff --git a/ports/stm32/qspi.c b/ports/stm32/qspi.c
@@ -232,8 +232,12 @@ STATIC int qspi_write_cmd_data(void *self_in, uint8_t cmd, size_t len, uint32_t
         while (!(QUADSPI->SR & QUADSPI_SR_FTF)) {
         }
 
-        // This assumes len==2
-        *(uint16_t *)&QUADSPI->DR = data;
+        if (len == 1) {
+            *(uint8_t *)&QUADSPI->DR = data;
+        } else {
+            // This assumes len==2
+            *(uint16_t *)&QUADSPI->DR = data;
+        }
     }
 
     // Wait for write to finish

Original file line number	Diff line number	Diff line change
`@@ -232,8 +232,12 @@ STATIC int qspi_write_cmd_data(void *self_in, uint8_t cmd, size_t len, uint32_t`
`232`	`232`	`while (!(QUADSPI->SR & QUADSPI_SR_FTF)) {`
`233`	`233`	`}`
`234`	`234`
`235`		`- // This assumes len==2`
`236`		`- (uint16_t )&QUADSPI->DR = data;`
	`235`	`+ if (len == 1) {`
	`236`	`+ (uint8_t )&QUADSPI->DR = data;`
	`237`	`+ } else {`
	`238`	`+ // This assumes len==2`
	`239`	`+ (uint16_t )&QUADSPI->DR = data;`
	`240`	`+ }`
`237`	`241`	`}`
`238`	`242`
`239`	`243`	`// Wait for write to finish`