162 lines
3.9 KiB
Diff
162 lines
3.9 KiB
Diff
From f85e6dacdb7d7a9bc37f33cf8770006ab64286f7 Mon Sep 17 00:00:00 2001
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From: John Crispin <blogic@openwrt.org>
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Date: Wed, 27 Nov 2013 20:58:16 +0100
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Subject: [PATCH 131/133] mtd: add chunked read io to m25p80
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Signed-off-by: John Crispin <blogic@openwrt.org>
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---
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drivers/mtd/devices/m25p80.c | 127 ++++++++++++++++++++++++++++++++++++++++++
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1 file changed, 127 insertions(+)
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--- a/drivers/mtd/devices/m25p80.c
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+++ b/drivers/mtd/devices/m25p80.c
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@@ -392,6 +392,58 @@ static int m25p80_read(struct mtd_info *
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return 0;
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}
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+static int m25p80_read_chunked(struct mtd_info *mtd, loff_t from, size_t len,
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+ size_t *retlen, u_char *buf)
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+{
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+ struct m25p *flash = mtd_to_m25p(mtd);
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+ struct spi_transfer t[2];
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+ struct spi_message m;
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+ uint8_t opcode;
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+ int idx = 0;
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+
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+ pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev),
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+ __func__, (u32)from, len);
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+
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+ spi_message_init(&m);
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+ memset(t, 0, (sizeof t));
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+
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+ t[0].tx_buf = flash->command;
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+ t[0].len = m25p_cmdsz(flash);
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+ spi_message_add_tail(&t[0], &m);
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+ spi_message_add_tail(&t[1], &m);
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+
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+ *retlen = 0;
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+
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+ while (idx < len) {
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+ int rlen = (len - idx > 4) ? (4) : (len - idx);
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+
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+ t[1].rx_buf = &buf[idx];
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+ t[1].len = rlen;
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+
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+ mutex_lock(&flash->lock);
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+
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+ /* Wait till previous write/erase is done. */
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+ if (wait_till_ready(flash)) {
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+ /* REVISIT status return?? */
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+ mutex_unlock(&flash->lock);
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+ return 1;
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+ }
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+
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+ /* Set up the write data buffer. */
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+ opcode = OPCODE_NORM_READ;
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+ flash->command[0] = opcode;
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+ m25p_addr2cmd(flash, from + idx, flash->command);
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+
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+ spi_sync(flash->spi, &m);
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+
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+ *retlen += m.actual_length - m25p_cmdsz(flash);
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+
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+ mutex_unlock(&flash->lock);
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+ idx += rlen;
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+ }
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+ return 0;
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+}
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+
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/*
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* Write an address range to the flash chip. Data must be written in
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* FLASH_PAGESIZE chunks. The address range may be any size provided
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@@ -479,6 +531,76 @@ static int m25p80_write(struct mtd_info
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return 0;
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}
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+static int m25p80_write_chunked(struct mtd_info *mtd, loff_t to, size_t len,
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+ size_t *retlen, const u_char *buf)
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+{
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+ struct m25p *flash = mtd_to_m25p(mtd);
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+ struct spi_transfer t;
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+ struct spi_message m;
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+ u32 i, page_size;
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+ u8 tmp[8];
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+
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+ pr_debug("%s: %s to 0x%08x, len %zd\n", dev_name(&flash->spi->dev),
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+ __func__, (u32)to, len);
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+
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+ spi_message_init(&m);
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+ memset(&t, 0, (sizeof t));
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+
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+ t.tx_buf = tmp;
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+ t.len = 8;
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+ spi_message_add_tail(&t, &m);
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+
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+ mutex_lock(&flash->lock);
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+
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+ /* Wait until finished previous write command. */
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+ if (wait_till_ready(flash)) {
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+ mutex_unlock(&flash->lock);
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+ return 1;
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+ }
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+
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+ write_enable(flash);
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+
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+ /* Set up the opcode in the write buffer. */
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+ flash->command[0] = OPCODE_PP;
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+ m25p_addr2cmd(flash, to, flash->command);
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+
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+ t.len = 4 + (to & 0x3);
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+ if (t.len == 4)
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+ t.len = 8;
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+ memcpy(tmp, flash->command, 4);
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+ memcpy(&tmp[4], buf, t.len - 4);
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+ spi_sync(flash->spi, &m);
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+ page_size = t.len - 4;
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+
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+ *retlen = m.actual_length - m25p_cmdsz(flash);
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+
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+ /* write everything in flash->page_size chunks */
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+ for (i = page_size; i < len; i += page_size) {
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+ page_size = len - i;
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+ if (page_size > 4)
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+ page_size = 4;
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+
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+ /* write the next page to flash */
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+ m25p_addr2cmd(flash, to + i, flash->command);
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+
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+ memcpy(tmp, flash->command, 4);
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+ memcpy(&tmp[4], buf + i, page_size);
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+ t.len = 4 + page_size;
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+
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+ wait_till_ready(flash);
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+
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+ write_enable(flash);
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+
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+ spi_sync(flash->spi, &m);
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+
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+ *retlen += m.actual_length - m25p_cmdsz(flash);
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+ }
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+
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+ mutex_unlock(&flash->lock);
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+
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+ return 0;
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+}
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+
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static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
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size_t *retlen, const u_char *buf)
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{
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@@ -1059,6 +1181,12 @@ static int m25p_probe(struct spi_device
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flash->fast_read = true;
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#endif
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+ if (np && of_property_read_bool(np, "m25p,chunked-io")) {
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+ dev_warn(&spi->dev, "using chunked io\n");
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+ flash->mtd._read = m25p80_read_chunked;
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+ flash->mtd._write = m25p80_write_chunked;
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+ }
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+
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#ifdef CONFIG_M25PXX_USE_FAST_READ
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flash->fast_read = true;
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#endif
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