93 lines
2.8 KiB
Diff
93 lines
2.8 KiB
Diff
|
From 5fb4e8d7287ac8fcb33aae8b1e9e22c5a3c392bd Mon Sep 17 00:00:00 2001
|
||
|
|
From: Jonas Gorski <jonas.gorski@gmail.com>
|
||
|
|
Date: Thu, 10 Nov 2011 17:33:40 +0100
|
||
|
|
Subject: [PATCH 51/79] MTD: DEVICES: m25p80: add support for limiting reads
|
||
|
|
|
||
|
|
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
|
||
|
|
---
|
||
|
|
drivers/mtd/devices/m25p80.c | 29 +++++++++++++++++++++++++++--
|
||
|
|
include/linux/spi/flash.h | 4 ++++
|
||
|
|
2 files changed, 31 insertions(+), 2 deletions(-)
|
||
|
|
|
||
|
|
--- a/drivers/mtd/devices/m25p80.c
|
||
|
|
+++ b/drivers/mtd/devices/m25p80.c
|
||
|
|
@@ -100,6 +100,7 @@ struct m25p {
|
||
|
|
u16 addr_width;
|
||
|
|
u8 erase_opcode;
|
||
|
|
u8 *command;
|
||
|
|
+ int max_transfer_len;
|
||
|
|
};
|
||
|
|
|
||
|
|
static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd)
|
||
|
|
@@ -343,10 +344,9 @@ static int m25p80_erase(struct mtd_info
|
||
|
|
* Read an address range from the flash chip. The address range
|
||
|
|
* may be any size provided it is within the physical boundaries.
|
||
|
|
*/
|
||
|
|
-static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
|
||
|
|
+static int __m25p80_read(struct m25p *flash, 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;
|
||
|
|
|
||
|
|
@@ -395,6 +395,28 @@ static int m25p80_read(struct mtd_info *
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
+static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
|
||
|
|
+ size_t *retlen, u_char *buf)
|
||
|
|
+{
|
||
|
|
+ struct m25p *flash = mtd_to_m25p(mtd);
|
||
|
|
+ size_t off;
|
||
|
|
+ size_t read_len = flash->max_transfer_len;
|
||
|
|
+ size_t part_len;
|
||
|
|
+ int ret = 0;
|
||
|
|
+
|
||
|
|
+ if (!read_len)
|
||
|
|
+ return __m25p80_read(flash, from, len, retlen, buf);
|
||
|
|
+
|
||
|
|
+ *retlen = 0;
|
||
|
|
+
|
||
|
|
+ for (off = 0; off < len && !ret; off += read_len) {
|
||
|
|
+ ret = __m25p80_read(flash, from + off, min(len - off, read_len),
|
||
|
|
+ &part_len, buf + off);
|
||
|
|
+ *retlen += part_len;
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
+ return ret;
|
||
|
|
+}
|
||
|
|
/*
|
||
|
|
* Write an address range to the flash chip. Data must be written in
|
||
|
|
* FLASH_PAGESIZE chunks. The address range may be any size provided
|
||
|
|
@@ -886,6 +908,9 @@ static int __devinit m25p_probe(struct s
|
||
|
|
return -ENOMEM;
|
||
|
|
}
|
||
|
|
|
||
|
|
+ if (data)
|
||
|
|
+ flash->max_transfer_len = data->max_transfer_len;
|
||
|
|
+
|
||
|
|
flash->spi = spi;
|
||
|
|
mutex_init(&flash->lock);
|
||
|
|
dev_set_drvdata(&spi->dev, flash);
|
||
|
|
--- a/include/linux/spi/flash.h
|
||
|
|
+++ b/include/linux/spi/flash.h
|
||
|
|
@@ -13,6 +13,8 @@ struct mtd_part_parser_data;
|
||
|
|
* @part_probe_types: optional list of MTD parser names to use for
|
||
|
|
* partitioning
|
||
|
|
*
|
||
|
|
+ * @max_transfer_len: option maximum read/write length limitation for
|
||
|
|
+ * SPI controllers not able to transfer any length commands.
|
||
|
|
* Board init code (in arch/.../mach-xxx/board-yyy.c files) can
|
||
|
|
* provide information about SPI flash parts (such as DataFlash) to
|
||
|
|
* help set up the device and its appropriate default partitioning.
|
||
|
|
@@ -28,6 +30,8 @@ struct flash_platform_data {
|
||
|
|
char *type;
|
||
|
|
|
||
|
|
const char **part_probe_types;
|
||
|
|
+
|
||
|
|
+ unsigned int max_transfer_len;
|
||
|
|
/* we'll likely add more ... use JEDEC IDs, etc */
|
||
|
|
};
|
||
|
|
|