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mtd: mxc-nand: Do the word to byte mangling in the read_byte callback

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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>
This commit is contained in:
Uwe Kleine-König 2015-02-10 19:59:57 +01:00 committed by Brian Norris
parent 1f42adc888
commit 3f410690f5
1 changed files with 10 additions and 24 deletions
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34
drivers/mtd/nand/mxc_nand.c
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@ -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;
}