|
|
@@ -0,0 +1,81 @@
|
|
|
+From ccc38234fdc70120be79e7fb2df5c27ca5cd4c8a Mon Sep 17 00:00:00 2001
|
|
|
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <[email protected]>
|
|
|
+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 <[email protected]>
|
|
|
+Acked-by: Marek Vasut <[email protected]>
|
|
|
+Signed-off-by: Brian Norris <[email protected]>
|
|
|
+---
|
|
|
+ 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
|