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drivers: mtd: m25p80: convert "bool" read check into an enum 

This is a cleanup prior to adding quad read support. This will facilitate
easy addition of more read commands check under an enum rather that defining a
separate bool for it.

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
This commit is contained in:
Sourav Poddar 2013-11-06 20:05:34 +05:30 committed by Brian Norris
parent 802eee95bd
commit 8552b439ab
1 changed files with 57 additions and 14 deletions
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71
drivers/mtd/devices/m25p80.c
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@ -84,6 +84,11 @@
/****************************************************************************/
enum read_type {
M25P80_NORMAL = 0,
M25P80_FAST,
};
struct m25p {
struct spi_device *spi;
struct mutex lock;
@ -94,7 +99,7 @@ struct m25p {
u8 read_opcode;
u8 program_opcode;
u8 *command;
bool fast_read;
enum read_type flash_read;
};
static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd)
@ -349,6 +354,24 @@ static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
return 0;
}
/*
* Dummy Cycle calculation for different type of read.
* It can be used to support more commands with
* different dummy cycle requirements.
*/
static inline int m25p80_dummy_cycles_read(struct m25p *flash)
{
switch (flash->flash_read) {
case M25P80_FAST:
return 1;
case M25P80_NORMAL:
return 0;
default:
dev_err(&flash->spi->dev, "No valid read type supported\n");
return -1;
}
}
/*
* Read an address range from the flash chip. The address range
* may be any size provided it is within the physical boundaries.
@ -360,6 +383,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
struct spi_transfer t[2];
struct spi_message m;
uint8_t opcode;
int dummy;
pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev),
__func__, (u32)from, len);
@ -367,8 +391,14 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
spi_message_init(&m);
memset(t, 0, (sizeof t));
dummy = m25p80_dummy_cycles_read(flash);
if (dummy < 0) {
dev_err(&flash->spi->dev, "No valid read command supported\n");
return -EINVAL;
}
t[0].tx_buf = flash->command;
t[0].len = m25p_cmdsz(flash) + (flash->fast_read ? 1 : 0);
t[0].len = m25p_cmdsz(flash) + dummy;
spi_message_add_tail(&t[0], &m);
t[1].rx_buf = buf;
@ -391,8 +421,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
spi_sync(flash->spi, &m);
*retlen = m.actual_length - m25p_cmdsz(flash) -
(flash->fast_read ? 1 : 0);
*retlen = m.actual_length - m25p_cmdsz(flash) - dummy;
mutex_unlock(&flash->lock);
@ -1051,22 +1080,31 @@ static int m25p_probe(struct spi_device *spi)
flash->page_size = info->page_size;
flash->mtd.writebufsize = flash->page_size;
if (np)
if (np) {
/* If we were instantiated by DT, use it */
flash->fast_read = of_property_read_bool(np, "m25p,fast-read");
else
if (of_property_read_bool(np, "m25p,fast-read"))
flash->flash_read = M25P80_FAST;
} else {
/* If we weren't instantiated by DT, default to fast-read */
flash->fast_read = true;
flash->flash_read = M25P80_FAST;
}
/* Some devices cannot do fast-read, no matter what DT tells us */
if (info->flags & M25P_NO_FR)
flash->fast_read = false;
flash->flash_read = M25P80_NORMAL;
/* Default commands */
if (flash->fast_read)
switch (flash->flash_read) {
case M25P80_FAST:
flash->read_opcode = OPCODE_FAST_READ;
else
break;
case M25P80_NORMAL:
flash->read_opcode = OPCODE_NORM_READ;
break;
default:
dev_err(&flash->spi->dev, "No Read opcode defined\n");
return -EINVAL;
}
flash->program_opcode = OPCODE_PP;
@ -1077,9 +1115,14 @@ static int m25p_probe(struct spi_device *spi)
flash->addr_width = 4;
if (JEDEC_MFR(info->jedec_id) == CFI_MFR_AMD) {
/* Dedicated 4-byte command set */
flash->read_opcode = flash->fast_read ?
OPCODE_FAST_READ_4B :
OPCODE_NORM_READ_4B;
switch (flash->flash_read) {
case M25P80_FAST:
flash->read_opcode = OPCODE_FAST_READ_4B;
break;
case M25P80_NORMAL:
flash->read_opcode = OPCODE_NORM_READ_4B;
break;
}
flash->program_opcode = OPCODE_PP_4B;
/* No small sector erase for 4-byte command set */
flash->erase_opcode = OPCODE_SE_4B;