diff options
Diffstat (limited to 'target/linux/generic/patches-4.4/042-0006-mtd-bcm47xxsflash-support-reading-flash-out-of-mappi.patch')
| -rw-r--r-- | target/linux/generic/patches-4.4/042-0006-mtd-bcm47xxsflash-support-reading-flash-out-of-mappi.patch | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/target/linux/generic/patches-4.4/042-0006-mtd-bcm47xxsflash-support-reading-flash-out-of-mappi.patch b/target/linux/generic/patches-4.4/042-0006-mtd-bcm47xxsflash-support-reading-flash-out-of-mappi.patch new file mode 100644 index 0000000000..ecdae2a871 --- /dev/null +++ b/target/linux/generic/patches-4.4/042-0006-mtd-bcm47xxsflash-support-reading-flash-out-of-mappi.patch @@ -0,0 +1,81 @@ +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 |