mtd: brcmnand: clean up flash cache for parameter pages

The read_byte() handling for accessing the flash cache has some awkward
swapping being done in the read_byte() function. Let's just make this a
byte array, and do the swapping with the word-level macros during the
initial buffer copy.

This is just a refactoring patch, with no (intended) functional change.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Clay McClure <clay@daemons.net>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: <bcm-kernel-feedback-list@broadcom.com>
Tested-by: Clay McClure <clay@daemons.net>

diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
index 2a437c7..0f43bc9 100644 (file)
--- a/drivers/mtd/nand/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/brcmnand/brcmnand.c
@@ -134,7 +134,7 @@ struct brcmnand_controller {
        dma_addr_t              dma_pa;
 
        /* in-memory cache of the FLASH_CACHE, used only for some commands */
-       u32                     flash_cache[FC_WORDS];
+       u8                      flash_cache[FC_BYTES];
 
        /* Controller revision details */
        const u16               *reg_offsets;
@@ -1188,6 +1188,8 @@ static void brcmnand_cmdfunc(struct mtd_info *mtd, unsigned command,
 
        if (native_cmd == CMD_PARAMETER_READ ||
                        native_cmd == CMD_PARAMETER_CHANGE_COL) {
+               /* Copy flash cache word-wise */
+               u32 *flash_cache = (u32 *)ctrl->flash_cache;
                int i;
 
                brcmnand_soc_data_bus_prepare(ctrl->soc);
@@ -1197,7 +1199,11 @@ static void brcmnand_cmdfunc(struct mtd_info *mtd, unsigned command,
                 * SECTOR_SIZE_1K may invalidate it
                 */
                for (i = 0; i < FC_WORDS; i++)
-                       ctrl->flash_cache[i] = brcmnand_read_fc(ctrl, i);
+                       /*
+                        * Flash cache is big endian for parameter pages, at
+                        * least on STB SoCs
+                        */
+                       flash_cache[i] = be32_to_cpu(brcmnand_read_fc(ctrl, i));
 
                brcmnand_soc_data_bus_unprepare(ctrl->soc);
 
@@ -1250,8 +1256,7 @@ static uint8_t brcmnand_read_byte(struct mtd_info *mtd)
                if (host->last_byte > 0 && offs == 0)
                        chip->cmdfunc(mtd, NAND_CMD_RNDOUT, addr, -1);
 
-               ret = ctrl->flash_cache[offs >> 2] >>
-                                       (24 - ((offs & 0x03) << 3));
+               ret = ctrl->flash_cache[offs];
                break;
        case NAND_CMD_GET_FEATURES:
                if (host->last_byte >= ONFI_SUBFEATURE_PARAM_LEN) {