@@ -3245,11 +3245,15 @@ ident_done:
break;
}
- /*
- * Check, if buswidth is correct. Hardware drivers should set
- * chip correct!
- */
- if (busw != (chip->options & NAND_BUSWIDTH_16)) {
+ if (chip->options & NAND_BUSWIDTH_AUTO) {
+ WARN_ON(chip->options & NAND_BUSWIDTH_16);
+ chip->options |= busw;
+ nand_set_defaults(chip, busw);
+ } else if (busw != (chip->options & NAND_BUSWIDTH_16)) {
+ /*
+ * Check, if buswidth is correct. Hardware drivers should set
+ * chip correct!
+ */
pr_info("NAND device: Manufacturer ID:"
" 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id,
*dev_id, nand_manuf_ids[maf_idx].name, mtd->name);
@@ -219,6 +219,13 @@ typedef enum {
#define NAND_OWN_BUFFERS 0x00020000
/* Chip may not exist, so silence any errors in scan */
#define NAND_SCAN_SILENT_NODEV 0x00040000
+/*
+ * Autodetect nand buswidth with readid/onfi.
+ * This suppose the driver will configure the hardware in 8 bits mode
+ * when calling nand_scan_ident, and update its configuration
+ * before calling nand_scan_tail.
+ */
+#define NAND_BUSWIDTH_AUTO 0x00080000
/* Options set by nand scan */
/* Nand scan has allocated controller struct */
The driver call nand_scan_ident in 8 bit mode, then readid or onfi detection are done (and detect bus width). The driver should update its bus width before calling nand_scan_tail. This work because readid and onfi are read work 8 byte mode. Note that nand_scan_ident send command (NAND_CMD_RESET, NAND_CMD_READID, NAND_CMD_PARAM), address and read data The ONFI specificication is not very clear for x16 device if high byte of address should be driven to 0, but according to [1] it should be ok to not drive it during autodetection. [1] 3.3.2. Target Initialization [...] The Read ID and Read Parameter Page commands only use the lower 8-bits of the data bus. The host shall not issue commands that use a word data width on x16 devices until the host determines the device supports a 16-bit data bus width in the parameter page. Signed-off-by: Matthieu CASTET <matthieu.castet@parrot.com> --- drivers/mtd/nand/nand_base.c | 14 +++++++++----- include/linux/mtd/nand.h | 7 +++++++ 2 files changed, 16 insertions(+), 5 deletions(-)