On 26 October 2015 at 21:41, Fabio Estevam fabio.estevam@freescale.com wrote:
Add the SPI NOR protection mechanism from the kernel.
This code is based on the work from Brian Norris computersforpeace@gmail.com
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/driv...
Signed-off-by: Fabio Estevam fabio.estevam@freescale.com Reviewed-by: Tom Rini trini@konsulko.com Reviewed-by: Heiko Schocher hs@denx.de
Reviewed-by: Jagan Teki jteki@openedev.com
Changes since v3:
- None
drivers/mtd/spi/sf_ops.c | 170 +++++++++++++++++++++++++++++++++++++++++++++++ include/spi_flash.h | 4 ++ 2 files changed, 174 insertions(+)
diff --git a/drivers/mtd/spi/sf_ops.c b/drivers/mtd/spi/sf_ops.c index 900ec1f..928f9c1 100644 --- a/drivers/mtd/spi/sf_ops.c +++ b/drivers/mtd/spi/sf_ops.c @@ -15,6 +15,7 @@ #include <spi_flash.h> #include <watchdog.h> #include <linux/compiler.h> +#include <linux/log2.h>
#include "sf_internal.h"
@@ -573,3 +574,172 @@ int sst_write_bp(struct spi_flash *flash, u32 offset, size_t len, return ret; } #endif
+#ifdef CONFIG_SPI_FLASH_STMICRO +static void stm_get_locked_range(struct spi_flash *flash, u8 sr, loff_t *ofs,
u32 *len)+{
u8 mask = SR_BP2 | SR_BP1 | SR_BP0;int shift = ffs(mask) - 1;int pow;if (!(sr & mask)) {/* No protection */*ofs = 0;*len = 0;} else {pow = ((sr & mask) ^ mask) >> shift;*len = flash->size >> pow;*ofs = flash->size - *len;}+}
+/*
- Return 1 if the entire region is locked, 0 otherwise
- */
+static int stm_is_locked_sr(struct spi_flash *flash, loff_t ofs, u32 len,
u8 sr)+{
loff_t lock_offs;u32 lock_len;stm_get_locked_range(flash, sr, &lock_offs, &lock_len);return (ofs + len <= lock_offs + lock_len) && (ofs >= lock_offs);+}
+/*
- Check if a region of the flash is (completely) locked. See stm_lock() for
- more info.
- Returns 1 if entire region is locked, 0 if any portion is unlocked, and
- negative on errors.
- */
+int stm_is_locked(struct spi_flash *flash, loff_t ofs, u32 len) +{
int status;u8 sr;status = spi_flash_cmd_read_status(flash, &sr);if (status < 0)return status;return stm_is_locked_sr(flash, ofs, len, sr);+}
+/*
- Lock a region of the flash. Compatible with ST Micro and similar flash.
- Supports only the block protection bits BP{0,1,2} in the status register
- (SR). Does not support these features found in newer SR bitfields:
- TB: top/bottom protect - only handle TB=0 (top protect)
- SEC: sector/block protect - only handle SEC=0 (block protect)
- CMP: complement protect - only support CMP=0 (range is not complemented)
- Sample table portion for 8MB flash (Winbond w25q64fw):
- SEC | TB | BP2 | BP1 | BP0 | Prot Length | Protected Portion
- X | X | 0 | 0 | 0 | NONE | NONE
- 0 | 0 | 0 | 0 | 1 | 128 KB | Upper 1/64
- 0 | 0 | 0 | 1 | 0 | 256 KB | Upper 1/32
- 0 | 0 | 0 | 1 | 1 | 512 KB | Upper 1/16
- 0 | 0 | 1 | 0 | 0 | 1 MB | Upper 1/8
- 0 | 0 | 1 | 0 | 1 | 2 MB | Upper 1/4
- 0 | 0 | 1 | 1 | 0 | 4 MB | Upper 1/2
- X | X | 1 | 1 | 1 | 8 MB | ALL
- Returns negative on errors, 0 on success.
- */
+int stm_lock(struct spi_flash *flash, u32 ofs, u32 len) +{
u8 status_old, status_new;u8 mask = SR_BP2 | SR_BP1 | SR_BP0;u8 shift = ffs(mask) - 1, pow, val;spi_flash_cmd_read_status(flash, &status_old);/* SPI NOR always locks to the end */if (ofs + len != flash->size) {/* Does combined region extend to end? */if (!stm_is_locked_sr(flash, ofs + len, flash->size - ofs - len,status_old))return -EINVAL;len = flash->size - ofs;}/** Need smallest pow such that:** 1 / (2^pow) <= (len / size)** so (assuming power-of-2 size) we do:** pow = ceil(log2(size / len)) = log2(size) - floor(log2(len))*/pow = ilog2(flash->size) - ilog2(len);val = mask - (pow << shift);if (val & ~mask)return -EINVAL;/* Don't "lock" with no region! */if (!(val & mask))return -EINVAL;status_new = (status_old & ~mask) | val;/* Only modify protection if it will not unlock other areas */if ((status_new & mask) <= (status_old & mask))return -EINVAL;spi_flash_cmd_write_status(flash, status_new);return 0;+}
+/*
- Unlock a region of the flash. See stm_lock() for more info
- Returns negative on errors, 0 on success.
- */
+int stm_unlock(struct spi_flash *flash, u32 ofs, u32 len) +{
uint8_t status_old, status_new;u8 mask = SR_BP2 | SR_BP1 | SR_BP0;u8 shift = ffs(mask) - 1, pow, val;spi_flash_cmd_read_status(flash, &status_old);/* Cannot unlock; would unlock larger region than requested */if (stm_is_locked_sr(flash, status_old, ofs - flash->erase_size,flash->erase_size))return -EINVAL;/** Need largest pow such that:** 1 / (2^pow) >= (len / size)** so (assuming power-of-2 size) we do:** pow = floor(log2(size / len)) = log2(size) - ceil(log2(len))*/pow = ilog2(flash->size) - order_base_2(flash->size - (ofs + len));if (ofs + len == flash->size) {val = 0; /* fully unlocked */} else {val = mask - (pow << shift);/* Some power-of-two sizes are not supported */if (val & ~mask)return -EINVAL;}status_new = (status_old & ~mask) | val;/* Only modify protection if it will not lock other areas */if ((status_new & mask) >= (status_old & mask))return -EINVAL;spi_flash_cmd_write_status(flash, status_new);return 0;+} +#endif /* CONFIG_SPI_FLASH_STMICRO */ diff --git a/include/spi_flash.h b/include/spi_flash.h index 3b2d555..73b2b0a 100644 --- a/include/spi_flash.h +++ b/include/spi_flash.h @@ -31,6 +31,10 @@ # define CONFIG_SF_DEFAULT_BUS 0 #endif
+#define SR_BP0 BIT(2) /* Block protect 0 */ +#define SR_BP1 BIT(3) /* Block protect 1 */ +#define SR_BP2 BIT(4) /* Block protect 2 */
But, these should be in sf_internal.h
struct spi_slave;
thanks!