From b6d5d4c3d595b4cfb6a052ac7151fdb1d9a776ea Mon Sep 17 00:00:00 2001 From: John Crispin 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 --- drivers/mtd/devices/m25p80.c | 128 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c index ad19139..6f4290e 100644 --- a/drivers/mtd/devices/m25p80.c +++ b/drivers/mtd/devices/m25p80.c @@ -556,6 +556,58 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len, 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 = 0; + + pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev), + __func__, (u32)from, len); + + 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; + + while (idx < len) { + int rlen = (len - idx > 4) ? (4) : (len - idx); + + t[1].rx_buf = &buf[idx]; + t[1].len = rlen; + + 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; + } + + /* 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); + idx += rlen; + } + return 0; +} + /* * Write an address range to the flash chip. Data must be written in * FLASH_PAGESIZE chunks. The address range may be any size provided @@ -643,6 +695,76 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len, return 0; } +static int m25p80_write_chunked(struct mtd_info *mtd, loff_t to, size_t len, + size_t *retlen, const u_char *buf) +{ + struct m25p *flash = mtd_to_m25p(mtd); + struct spi_transfer t; + struct spi_message m; + u32 i, page_size; + u8 tmp[8]; + + pr_debug("%s: %s to 0x%08x, len %zd\n", dev_name(&flash->spi->dev), + __func__, (u32)to, len); + + spi_message_init(&m); + memset(&t, 0, (sizeof t)); + + t.tx_buf = tmp; + t.len = 8; + spi_message_add_tail(&t, &m); + + mutex_lock(&flash->lock); + + /* Wait until finished previous write command. */ + if (wait_till_ready(flash)) { + mutex_unlock(&flash->lock); + return 1; + } + + write_enable(flash); + + /* Set up the opcode in the write buffer. */ + flash->command[0] = OPCODE_PP; + m25p_addr2cmd(flash, to, flash->command); + + t.len = 4 + (to & 0x3); + if (t.len == 4) + t.len = 8; + memcpy(tmp, flash->command, 4); + memcpy(&tmp[4], buf, t.len - 4); + spi_sync(flash->spi, &m); + page_size = t.len - 4; + + *retlen = m.actual_length - m25p_cmdsz(flash); + + /* write everything in flash->page_size chunks */ + for (i = page_size; i < len; i += page_size) { + page_size = len - i; + if (page_size > 4) + page_size = 4; + + /* write the next page to flash */ + m25p_addr2cmd(flash, to + i, flash->command); + + memcpy(tmp, flash->command, 4); + memcpy(&tmp[4], buf + i, page_size); + t.len = 4 + page_size; + + wait_till_ready(flash); + + write_enable(flash); + + spi_sync(flash->spi, &m); + + *retlen += m.actual_length - m25p_cmdsz(flash); + } + + mutex_unlock(&flash->lock); + + return 0; +} + static int sst_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) { @@ -1252,6 +1374,12 @@ static int m25p_probe(struct spi_device *spi) return -EINVAL; } + if (np && of_property_read_bool(np, "m25p,chunked-io")) { + dev_warn(&spi->dev, "using chunked io\n"); + flash->mtd._read = m25p80_read_chunked; + flash->mtd._write = m25p80_write_chunked; + } + flash->program_opcode = OPCODE_PP; if (info->addr_width) -- 1.7.10.4