82 lines
2.6 KiB
Diff
82 lines
2.6 KiB
Diff
From ccc38234fdc70120be79e7fb2df5c27ca5cd4c8a Mon Sep 17 00:00:00 2001
|
|
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
|
|
Date: Wed, 8 Feb 2017 23:53:44 +0100
|
|
Subject: [PATCH] mtd: bcm47xxsflash: support reading flash out of mapping
|
|
window
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
For reading flash content we use MMIO but it's possible to read only
|
|
first 16 MiB this way. It's simply an arch design/limitation.
|
|
To support flash sizes bigger than 16 MiB implement indirect access
|
|
using ChipCommon registers.
|
|
This has been tested using MX25L25635F.
|
|
|
|
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
|
|
Acked-by: Marek Vasut <marek.vasut@gmail.com>
|
|
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
|
|
---
|
|
drivers/mtd/devices/bcm47xxsflash.c | 24 +++++++++++++++++++++---
|
|
drivers/mtd/devices/bcm47xxsflash.h | 3 +++
|
|
2 files changed, 24 insertions(+), 3 deletions(-)
|
|
|
|
--- a/drivers/mtd/devices/bcm47xxsflash.c
|
|
+++ b/drivers/mtd/devices/bcm47xxsflash.c
|
|
@@ -105,15 +105,33 @@ static int bcm47xxsflash_read(struct mtd
|
|
size_t *retlen, u_char *buf)
|
|
{
|
|
struct bcm47xxsflash *b47s = mtd->priv;
|
|
+ size_t orig_len = len;
|
|
|
|
/* Check address range */
|
|
if ((from + len) > mtd->size)
|
|
return -EINVAL;
|
|
|
|
- memcpy_fromio(buf, b47s->window + from, len);
|
|
- *retlen = len;
|
|
+ /* Read as much as possible using fast MMIO window */
|
|
+ if (from < BCM47XXSFLASH_WINDOW_SZ) {
|
|
+ size_t memcpy_len;
|
|
|
|
- return len;
|
|
+ memcpy_len = min(len, (size_t)(BCM47XXSFLASH_WINDOW_SZ - from));
|
|
+ memcpy_fromio(buf, b47s->window + from, memcpy_len);
|
|
+ from += memcpy_len;
|
|
+ len -= memcpy_len;
|
|
+ buf += memcpy_len;
|
|
+ }
|
|
+
|
|
+ /* Use indirect access for content out of the window */
|
|
+ for (; len; len--) {
|
|
+ b47s->cc_write(b47s, BCMA_CC_FLASHADDR, from++);
|
|
+ bcm47xxsflash_cmd(b47s, OPCODE_ST_READ4B);
|
|
+ *buf++ = b47s->cc_read(b47s, BCMA_CC_FLASHDATA);
|
|
+ }
|
|
+
|
|
+ *retlen = orig_len;
|
|
+
|
|
+ return orig_len;
|
|
}
|
|
|
|
static int bcm47xxsflash_write_st(struct mtd_info *mtd, u32 offset, size_t len,
|
|
--- a/drivers/mtd/devices/bcm47xxsflash.h
|
|
+++ b/drivers/mtd/devices/bcm47xxsflash.h
|
|
@@ -3,6 +3,8 @@
|
|
|
|
#include <linux/mtd/mtd.h>
|
|
|
|
+#define BCM47XXSFLASH_WINDOW_SZ SZ_16M
|
|
+
|
|
/* Used for ST flashes only. */
|
|
#define OPCODE_ST_WREN 0x0006 /* Write Enable */
|
|
#define OPCODE_ST_WRDIS 0x0004 /* Write Disable */
|
|
@@ -16,6 +18,7 @@
|
|
#define OPCODE_ST_RES 0x03ab /* Read Electronic Signature */
|
|
#define OPCODE_ST_CSA 0x1000 /* Keep chip select asserted */
|
|
#define OPCODE_ST_SSE 0x0220 /* Sub-sector Erase */
|
|
+#define OPCODE_ST_READ4B 0x6313 /* Read Data Bytes in 4Byte addressing mode */
|
|
|
|
/* Used for Atmel flashes only. */
|
|
#define OPCODE_AT_READ 0x07e8
|