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From b6d5d4c3d595b4cfb6a052ac7151fdb1d9a776ea Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Sun, 27 Jul 2014 09:58:09 +0100
Subject: [PATCH 44/57] mtd: add chunked read io to m25p80
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
drivers/mtd/devices/m25p80.c | 128 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 128 insertions(+)
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -110,6 +110,7 @@ struct m25p {
struct mtd_info mtd;
u16 page_size;
u16 addr_width;
+ u16 chunk_size;
u8 erase_opcode;
u8 read_opcode;
u8 program_opcode;
@@ -562,6 +563,89 @@ static int m25p80_read(struct mtd_info *
return 0;
}
+static int m25p80_read_chunked(struct mtd_info *mtd, loff_t from, size_t len,
+ size_t *retlen, u_char *buf)
+{
+ struct m25p *flash = mtd_to_m25p(mtd);
+ struct spi_transfer t[2];
+ struct spi_message m;
+ uint8_t opcode;
+ int idx, rlen;
+
+ pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev),
+ __func__, (u32)from, len);
+
+ mutex_lock(&flash->lock);
+ /* Wait till previous write/erase is done. */
+ if (wait_till_ready(flash)) {
+ /* REVISIT status return?? */
+ mutex_unlock(&flash->lock);
+ return 1;
+ }
+
+ spi_message_init(&m);
+ memset(t, 0, (sizeof t));
+
+ t[0].tx_buf = flash->command;
+ t[0].len = m25p_cmdsz(flash);
+ spi_message_add_tail(&t[0], &m);
+ spi_message_add_tail(&t[1], &m);
+
+ *retlen = 0;
+
+ for (idx = 0; idx < len; idx += rlen) {
+ rlen = min_t(int, flash->chunk_size, len - idx);
+
+ if (idx)
+ wait_till_ready(flash);
+
+ t[1].rx_buf = &buf[idx];
+ t[1].len = rlen;
+
+ /* Set up the write data buffer. */
+ opcode = OPCODE_NORM_READ;
+ flash->command[0] = opcode;
+ m25p_addr2cmd(flash, from + idx, flash->command);
+
+ spi_sync(flash->spi, &m);
+
+ *retlen += m.actual_length - m25p_cmdsz(flash);
+ }
+
+ mutex_unlock(&flash->lock);
+
+ return 0;
+}
+
+static int m25p80_write_data(struct m25p *flash, struct spi_message *m,
+ struct spi_transfer *t, int to)
+{
+ const void *buf = t->tx_buf;
+ int len = t->len;
+ int retlen = 0;
+ int chunk_size;
+
+ chunk_size = flash->chunk_size;
+ if (!chunk_size)
+ chunk_size = len;
+
+ while (retlen < len) {
+ t->tx_buf = buf + retlen;
+ t->len = min_t(int, chunk_size, len - retlen);
+
+ if (retlen)
+ wait_till_ready(flash);
+
+ write_enable(flash);
+ m25p_addr2cmd(flash, to + retlen, flash->command);
+ spi_sync(flash->spi, m);
+
+ retlen += m->actual_length - m25p_cmdsz(flash);
+ }
+
+ return retlen;
+}
+
/*
* Write an address range to the flash chip. Data must be written in
* FLASH_PAGESIZE chunks. The address range may be any size provided
@@ -596,11 +680,8 @@ static int m25p80_write(struct mtd_info
return 1;
}
- write_enable(flash);
-
/* Set up the opcode in the write buffer. */
flash->command[0] = flash->program_opcode;
- m25p_addr2cmd(flash, to, flash->command);
page_offset = to & (flash->page_size - 1);
@@ -608,9 +689,7 @@ static int m25p80_write(struct mtd_info
if (page_offset + len <= flash->page_size) {
t[1].len = len;
- spi_sync(flash->spi, &m);
-
- *retlen = m.actual_length - m25p_cmdsz(flash);
+ *retlen = m25p80_write_data(flash, &m, &t[1], to);
} else {
u32 i;
@@ -618,9 +697,7 @@ static int m25p80_write(struct mtd_info
page_size = flash->page_size - page_offset;
t[1].len = page_size;
- spi_sync(flash->spi, &m);
-
- *retlen = m.actual_length - m25p_cmdsz(flash);
+ *retlen = m25p80_write_data(flash, &m, &t[1], to);
/* write everything in flash->page_size chunks */
for (i = page_size; i < len; i += page_size) {
@@ -628,19 +705,12 @@ static int m25p80_write(struct mtd_info
if (page_size > flash->page_size)
page_size = flash->page_size;
- /* write the next page to flash */
- m25p_addr2cmd(flash, to + i, flash->command);
-
t[1].tx_buf = buf + i;
t[1].len = page_size;
wait_till_ready(flash);
- write_enable(flash);
-
- spi_sync(flash->spi, &m);
-
- *retlen += m.actual_length - m25p_cmdsz(flash);
+ *retlen += m25p80_write_data(flash, &m, &t[1], to + i);
}
}
@@ -1105,6 +1175,7 @@ static int m25p_probe(struct spi_device
struct mtd_part_parser_data ppdata;
struct device_node *np = spi->dev.of_node;
int ret;
+ u32 val;
/* Platform data helps sort out which chip type we have, as
* well as how this board partitions it. If we don't have
@@ -1187,6 +1258,12 @@ static int m25p_probe(struct spi_device
flash->mtd._erase = m25p80_erase;
flash->mtd._read = m25p80_read;
+ if (np && !of_property_read_u32(np, "m25p,chunked-io", &val)) {
+ dev_warn(&spi->dev, "using chunked io\n");
+ flash->mtd._read = m25p80_read_chunked;
+ flash->chunk_size = val;
+ }
+
/* flash protection support for STmicro chips */
if (JEDEC_MFR(info->jedec_id) == CFI_MFR_ST) {
flash->mtd._lock = m25p80_lock;
|
