spi: nxp-fspi: Add support for IP read only
Add support for disabling AHB bus and read entire flash contents via IP
bus only. Please note, this enables IP bus read using a quirk which can
be enabled directly in device-type data or in existence of an errata
where AHB bus may need to be disabled.
Signed-off-by: Kuldeep Singh <kuldeep.singh@nxp.com>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/drivers/spi/nxp_fspi.c b/drivers/spi/nxp_fspi.c
index bba7a33..7715ed9 100644
--- a/drivers/spi/nxp_fspi.c
+++ b/drivers/spi/nxp_fspi.c
@@ -304,6 +304,9 @@
#define POLL_TOUT 5000
#define NXP_FSPI_MAX_CHIPSELECT 4
+/* Access flash memory using IP bus only */
+#define FSPI_QUIRK_USE_IP_ONLY BIT(0)
+
struct nxp_fspi_devtype_data {
unsigned int rxfifo;
unsigned int txfifo;
@@ -338,6 +341,11 @@
const struct nxp_fspi_devtype_data *devtype_data;
};
+static inline int needs_ip_only(struct nxp_fspi *f)
+{
+ return f->devtype_data->quirks & FSPI_QUIRK_USE_IP_ONLY;
+}
+
/*
* R/W functions for big- or little-endian registers:
* The FSPI controller's endianness is independent of
@@ -769,12 +777,14 @@
nxp_fspi_prepare_lut(f, op);
/*
- * If we have large chunks of data, we read them through the AHB bus
- * by accessing the mapped memory. In all other cases we use
- * IP commands to access the flash.
+ * If we have large chunks of data, we read them through the AHB bus by
+ * accessing the mapped memory. In all other cases we use IP commands
+ * to access the flash. Read via AHB bus may be corrupted due to
+ * existence of an errata and therefore discard AHB read in such cases.
*/
if (op->data.nbytes > (f->devtype_data->rxfifo - 4) &&
- op->data.dir == SPI_MEM_DATA_IN) {
+ op->data.dir == SPI_MEM_DATA_IN &&
+ !needs_ip_only(f)) {
nxp_fspi_read_ahb(f, op);
} else {
if (op->data.nbytes && op->data.dir == SPI_MEM_DATA_OUT)
@@ -808,6 +818,12 @@
op->data.nbytes = ALIGN_DOWN(op->data.nbytes, 8);
}
+ /* Limit data bytes to RX FIFO in case of IP read only */
+ if (needs_ip_only(f) &&
+ op->data.dir == SPI_MEM_DATA_IN &&
+ op->data.nbytes > f->devtype_data->rxfifo)
+ op->data.nbytes = f->devtype_data->rxfifo;
+
return 0;
}