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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2015-02-10 18:59:57 (GMT)
committerBrian Norris <computersforpeace@gmail.com>2015-03-11 22:20:29 (GMT)
commit3f410690f511f9531fdc0865a931522b049d7b29 (patch)
tree85ec5c38dab6ea75421ec1109c3d18a01e6b8dd2 /drivers/mtd/nand/mxc_nand.c
parent1f42adc8880d0692c3cb7b6adb247f17c4983081 (diff)
downloadlinux-3f410690f511f9531fdc0865a931522b049d7b29.tar.xz
mtd: mxc-nand: Do the word to byte mangling in the read_byte callback
When the hardware operates in 16 bit mode it always reads 16 bits even for operations that only have the lower 8 bits defined. So the upper bits must be discarded. Do this in the read_byte callback instead of when reading the NAND id to support reading byte wise more than 5 bytes and at other occations (like reading the ONFI parameter page). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Diffstat (limited to 'drivers/mtd/nand/mxc_nand.c')
-rw-r--r--drivers/mtd/nand/mxc_nand.c34
1 files changed, 10 insertions, 24 deletions
diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index d9637ae..aa98a0d 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -552,30 +552,17 @@ static void send_page_v1(struct mtd_info *mtd, unsigned int ops)
static void send_read_id_v3(struct mxc_nand_host *host)
{
- struct nand_chip *this = &host->nand;
-
/* Read ID into main buffer */
writel(NFC_ID, NFC_V3_LAUNCH);
wait_op_done(host, true);
memcpy32_fromio(host->data_buf, host->main_area0, 16);
-
- if (this->options & NAND_BUSWIDTH_16) {
- /* compress the ID info */
- host->data_buf[1] = host->data_buf[2];
- host->data_buf[2] = host->data_buf[4];
- host->data_buf[3] = host->data_buf[6];
- host->data_buf[4] = host->data_buf[8];
- host->data_buf[5] = host->data_buf[10];
- }
}
/* Request the NANDFC to perform a read of the NAND device ID. */
static void send_read_id_v1_v2(struct mxc_nand_host *host)
{
- struct nand_chip *this = &host->nand;
-
/* NANDFC buffer 0 is used for device ID output */
writew(host->active_cs << 4, NFC_V1_V2_BUF_ADDR);
@@ -585,15 +572,6 @@ static void send_read_id_v1_v2(struct mxc_nand_host *host)
wait_op_done(host, true);
memcpy32_fromio(host->data_buf, host->main_area0, 16);
-
- if (this->options & NAND_BUSWIDTH_16) {
- /* compress the ID info */
- host->data_buf[1] = host->data_buf[2];
- host->data_buf[2] = host->data_buf[4];
- host->data_buf[3] = host->data_buf[6];
- host->data_buf[4] = host->data_buf[8];
- host->data_buf[5] = host->data_buf[10];
- }
}
static uint16_t get_dev_status_v3(struct mxc_nand_host *host)
@@ -719,9 +697,17 @@ static u_char mxc_nand_read_byte(struct mtd_info *mtd)
if (host->status_request)
return host->devtype_data->get_dev_status(host) & 0xFF;
- ret = *(uint8_t *)(host->data_buf + host->buf_start);
- host->buf_start++;
+ if (nand_chip->options & NAND_BUSWIDTH_16) {
+ /* only take the lower byte of each word */
+ ret = *(uint16_t *)(host->data_buf + host->buf_start);
+
+ host->buf_start += 2;
+ } else {
+ ret = *(uint8_t *)(host->data_buf + host->buf_start);
+ host->buf_start++;
+ }
+ pr_debug("%s: ret=0x%hhx (start=%u)\n", __func__, ret, host->buf_start);
return ret;
}