cfi_flash: Introduce read and write accessors

Introduce flash_read{8,16,32,64) and flash_write{8,16,32,64} and use
them to access the flash memory. This makes it clearer when the flash
is actually being accessed; merely dereferencing a volatile pointer
looks just like any other kind of access.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index a89fcae446e243dc67cab9b624c8ead776b2ded5..d33725d00da4e6165e78bd6473a6f7814fe85918 100644 (file)
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -149,13 +149,6 @@ typedef union {
        unsigned long long ll;
 } cfiword_t;
 
-typedef union {
-       volatile unsigned char *cp;
-       volatile unsigned short *wp;
-       volatile unsigned long *lp;
-       volatile unsigned long long *llp;
-} cfiptr_t;
-
 #define NUM_ERASE_REGIONS      4 /* max. number of erase regions */
 
 static uint flash_offset_cfi[2] = { FLASH_OFFSET_CFI, FLASH_OFFSET_CFI_ALT };
@@ -178,6 +171,48 @@ flash_info_t flash_info[CFG_MAX_FLASH_BANKS];              /* FLASH chips info */
 
 typedef unsigned long flash_sect_t;
 
+static void flash_write8(u8 value, void *addr)
+{
+       __raw_writeb(value, addr);
+}
+
+static void flash_write16(u16 value, void *addr)
+{
+       __raw_writew(value, addr);
+}
+
+static void flash_write32(u32 value, void *addr)
+{
+       __raw_writel(value, addr);
+}
+
+static void flash_write64(u64 value, void *addr)
+{
+       /* No architectures currently implement __raw_writeq() */
+       *(volatile u64 *)addr = value;
+}
+
+static u8 flash_read8(void *addr)
+{
+       return __raw_readb(addr);
+}
+
+static u16 flash_read16(void *addr)
+{
+       return __raw_readw(addr);
+}
+
+static u32 flash_read32(void *addr)
+{
+       return __raw_readl(addr);
+}
+
+static u64 flash_read64(void *addr)
+{
+       /* No architectures currently implement __raw_readq() */
+       return *(volatile u64 *)addr;
+}
+
 /*-----------------------------------------------------------------------
  */
 #if defined(CFG_ENV_IS_IN_FLASH) || defined(CFG_ENV_ADDR_REDUND) || (CFG_MONITOR_BASE >= CFG_FLASH_BASE)
@@ -238,21 +273,21 @@ static void print_longlong (char *str, unsigned long long data)
 
 static void flash_printqry (flash_info_t * info, flash_sect_t sect)
 {
-       cfiptr_t cptr;
+       void *addr;
        int x, y;
 
        for (x = 0; x < 0x40; x += 16U / info->portwidth) {
-               cptr.cp =
-                       flash_make_addr (info, sect,
-                                        x + FLASH_OFFSET_CFI_RESP);
-               debug ("%p : ", cptr.cp);
+               addr = flash_make_addr (info, sect,
+                                       x + FLASH_OFFSET_CFI_RESP);
+               debug ("%p : ", addr);
                for (y = 0; y < 16; y++) {
-                       debug ("%2.2x ", cptr.cp[y]);
+                       debug ("%2.2x ", flash_read8(addr + y));
                }
                debug (" ");
                for (y = 0; y < 16; y++) {
-                       if (cptr.cp[y] >= 0x20 && cptr.cp[y] <= 0x7e) {
-                               debug ("%c", cptr.cp[y]);
+                       unsigned char c = flash_read8(addr + y);
+                       if (c >= 0x20 && c <= 0x7e) {
+                               debug ("%c", c);
                        } else {
                                debug (".");
                        }
@@ -352,28 +387,28 @@ static void flash_write_cmd (flash_info_t * info, flash_sect_t sect,
                             uint offset, uchar cmd)
 {
 
-       volatile cfiptr_t addr;
+       void *addr;
        cfiword_t cword;
 
-       addr.cp = flash_make_addr (info, sect, offset);
+       addr = flash_make_addr (info, sect, offset);
        flash_make_cmd (info, cmd, &cword);
        switch (info->portwidth) {
        case FLASH_CFI_8BIT:
-               debug ("fwc addr %p cmd %x %x 8bit x %d bit\n", addr.cp, cmd,
+               debug ("fwc addr %p cmd %x %x 8bit x %d bit\n", addr, cmd,
                       cword.c, info->chipwidth << CFI_FLASH_SHIFT_WIDTH);
-               *addr.cp = cword.c;
+               flash_write8(cword.c, addr);
                break;
        case FLASH_CFI_16BIT:
-               debug ("fwc addr %p cmd %x %4.4x 16bit x %d bit\n", addr.wp,
+               debug ("fwc addr %p cmd %x %4.4x 16bit x %d bit\n", addr,
                       cmd, cword.w,
                       info->chipwidth << CFI_FLASH_SHIFT_WIDTH);
-               *addr.wp = cword.w;
+               flash_write16(cword.w, addr);
                break;
        case FLASH_CFI_32BIT:
-               debug ("fwc addr %p cmd %x %8.8lx 32bit x %d bit\n", addr.lp,
+               debug ("fwc addr %p cmd %x %8.8lx 32bit x %d bit\n", addr,
                       cmd, cword.l,
                       info->chipwidth << CFI_FLASH_SHIFT_WIDTH);
-               *addr.lp = cword.l;
+               flash_write32(cword.l, addr);
                break;
        case FLASH_CFI_64BIT:
 #ifdef DEBUG
@@ -383,11 +418,11 @@ static void flash_write_cmd (flash_info_t * info, flash_sect_t sect,
                        print_longlong (str, cword.ll);
 
                        debug ("fwrite addr %p cmd %x %s 64 bit x %d bit\n",
-                              addr.llp, cmd, str,
+                              addr, cmd, str,
                               info->chipwidth << CFI_FLASH_SHIFT_WIDTH);
                }
 #endif
-               *addr.llp = cword.ll;
+               flash_write64(cword.ll, addr);
                break;
        }
 
@@ -406,26 +441,26 @@ static void flash_unlock_seq (flash_info_t * info, flash_sect_t sect)
 static int flash_isequal (flash_info_t * info, flash_sect_t sect,
                          uint offset, uchar cmd)
 {
-       cfiptr_t cptr;
+       void *addr;
        cfiword_t cword;
        int retval;
 
-       cptr.cp = flash_make_addr (info, sect, offset);
+       addr = flash_make_addr (info, sect, offset);
        flash_make_cmd (info, cmd, &cword);
 
-       debug ("is= cmd %x(%c) addr %p ", cmd, cmd, cptr.cp);
+       debug ("is= cmd %x(%c) addr %p ", cmd, cmd, addr);
        switch (info->portwidth) {
        case FLASH_CFI_8BIT:
-               debug ("is= %x %x\n", cptr.cp[0], cword.c);
-               retval = (cptr.cp[0] == cword.c);
+               debug ("is= %x %x\n", flash_read8(addr), cword.c);
+               retval = (flash_read8(addr) == cword.c);
                break;
        case FLASH_CFI_16BIT:
-               debug ("is= %4.4x %4.4x\n", cptr.wp[0], cword.w);
-               retval = (cptr.wp[0] == cword.w);
+               debug ("is= %4.4x %4.4x\n", flash_read16(addr), cword.w);
+               retval = (flash_read16(addr) == cword.w);
                break;
        case FLASH_CFI_32BIT:
-               debug ("is= %8.8lx %8.8lx\n", cptr.lp[0], cword.l);
-               retval = (cptr.lp[0] == cword.l);
+               debug ("is= %8.8lx %8.8lx\n", flash_read32(addr), cword.l);
+               retval = (flash_read32(addr) == cword.l);
                break;
        case FLASH_CFI_64BIT:
 #ifdef DEBUG
@@ -433,12 +468,12 @@ static int flash_isequal (flash_info_t * info, flash_sect_t sect,
                        char str1[20];
                        char str2[20];
 
-                       print_longlong (str1, cptr.llp[0]);
+                       print_longlong (str1, flash_read64(addr));
                        print_longlong (str2, cword.ll);
                        debug ("is= %s %s\n", str1, str2);
                }
 #endif
-               retval = (cptr.llp[0] == cword.ll);
+               retval = (flash_read64(addr) == cword.ll);
                break;
        default:
                retval = 0;
@@ -452,24 +487,24 @@ static int flash_isequal (flash_info_t * info, flash_sect_t sect,
 static int flash_isset (flash_info_t * info, flash_sect_t sect,
                        uint offset, uchar cmd)
 {
-       cfiptr_t cptr;
+       void *addr;
        cfiword_t cword;
        int retval;
 
-       cptr.cp = flash_make_addr (info, sect, offset);
+       addr = flash_make_addr (info, sect, offset);
        flash_make_cmd (info, cmd, &cword);
        switch (info->portwidth) {
        case FLASH_CFI_8BIT:
-               retval = ((cptr.cp[0] & cword.c) == cword.c);
+               retval = ((flash_read8(addr) & cword.c) == cword.c);
                break;
        case FLASH_CFI_16BIT:
-               retval = ((cptr.wp[0] & cword.w) == cword.w);
+               retval = ((flash_read16(addr) & cword.w) == cword.w);
                break;
        case FLASH_CFI_32BIT:
-               retval = ((cptr.lp[0] & cword.l) == cword.l);
+               retval = ((flash_read16(addr) & cword.l) == cword.l);
                break;
        case FLASH_CFI_64BIT:
-               retval = ((cptr.llp[0] & cword.ll) == cword.ll);
+               retval = ((flash_read64(addr) & cword.ll) == cword.ll);
                break;
        default:
                retval = 0;
@@ -483,25 +518,28 @@ static int flash_isset (flash_info_t * info, flash_sect_t sect,
 static int flash_toggle (flash_info_t * info, flash_sect_t sect,
                         uint offset, uchar cmd)
 {
-       cfiptr_t cptr;
+       void *addr;
        cfiword_t cword;
        int retval;
 
-       cptr.cp = flash_make_addr (info, sect, offset);
+       addr = flash_make_addr (info, sect, offset);
        flash_make_cmd (info, cmd, &cword);
        switch (info->portwidth) {
        case FLASH_CFI_8BIT:
-               retval = ((cptr.cp[0] & cword.c) != (cptr.cp[0] & cword.c));
+               retval = ((flash_read8(addr) & cword.c) !=
+                         (flash_read8(addr) & cword.c));
                break;
        case FLASH_CFI_16BIT:
-               retval = ((cptr.wp[0] & cword.w) != (cptr.wp[0] & cword.w));
+               retval = ((flash_read16(addr) & cword.w) !=
+                         (flash_read16(addr) & cword.w));
                break;
        case FLASH_CFI_32BIT:
-               retval = ((cptr.lp[0] & cword.l) != (cptr.lp[0] & cword.l));
+               retval = ((flash_read32(addr) & cword.l) !=
+                         (flash_read32(addr) & cword.l));
                break;
        case FLASH_CFI_64BIT:
-               retval = ((cptr.llp[0] & cword.ll) !=
-                         (cptr.llp[0] & cword.ll));
+               retval = ((flash_read64(addr) & cword.ll) !=
+                         (flash_read64(addr) & cword.ll));
                break;
        default:
                retval = 0;
@@ -676,26 +714,26 @@ static flash_sect_t find_sector (flash_info_t * info, ulong addr)
 static int flash_write_cfiword (flash_info_t * info, ulong dest,
                                cfiword_t cword)
 {
-       cfiptr_t ctladdr;
-       cfiptr_t cptr;
+       void *ctladdr;
+       void *dstaddr;
        int flag;
 
-       ctladdr.cp = flash_make_addr (info, 0, 0);
-       cptr.cp = (uchar *) dest;
+       ctladdr = flash_make_addr (info, 0, 0);
+       dstaddr = (uchar *)dest;
 
        /* Check if Flash is (sufficiently) erased */
        switch (info->portwidth) {
        case FLASH_CFI_8BIT:
-               flag = ((cptr.cp[0] & cword.c) == cword.c);
+               flag = ((flash_read8(dstaddr) & cword.c) == cword.c);
                break;
        case FLASH_CFI_16BIT:
-               flag = ((cptr.wp[0] & cword.w) == cword.w);
+               flag = ((flash_read16(dstaddr) & cword.w) == cword.w);
                break;
        case FLASH_CFI_32BIT:
-               flag = ((cptr.lp[0] & cword.l) == cword.l);
+               flag = ((flash_read32(dstaddr) & cword.l) == cword.l);
                break;
        case FLASH_CFI_64BIT:
-               flag = ((cptr.llp[0] & cword.ll) == cword.ll);
+               flag = ((flash_read64(dstaddr) & cword.ll) == cword.ll);
                break;
        default:
                return 2;
@@ -724,16 +762,16 @@ static int flash_write_cfiword (flash_info_t * info, ulong dest,
 
        switch (info->portwidth) {
        case FLASH_CFI_8BIT:
-               cptr.cp[0] = cword.c;
+               flash_write8(cword.c, dstaddr);
                break;
        case FLASH_CFI_16BIT:
-               cptr.wp[0] = cword.w;
+               flash_write16(cword.w, dstaddr);
                break;
        case FLASH_CFI_32BIT:
-               cptr.lp[0] = cword.l;
+               flash_write32(cword.l, dstaddr);
                break;
        case FLASH_CFI_64BIT:
-               cptr.llp[0] = cword.ll;
+               flash_write64(cword.ll, dstaddr);
                break;
        }
 
@@ -753,15 +791,14 @@ static int flash_write_cfibuffer (flash_info_t * info, ulong dest, uchar * cp,
        flash_sect_t sector;
        int cnt;
        int retcode;
-       volatile cfiptr_t src;
-       volatile cfiptr_t dst;
+       void *src = cp;
+       void *dst = (void *)dest;
+
+       sector = find_sector (info, dest);
 
        switch (info->vendor) {
        case CFI_CMDSET_INTEL_STANDARD:
        case CFI_CMDSET_INTEL_EXTENDED:
-               src.cp = cp;
-               dst.cp = (uchar *) dest;
-               sector = find_sector (info, dest);
                flash_write_cmd (info, sector, 0, FLASH_CMD_CLEAR_STATUS);
                flash_write_cmd (info, sector, 0, FLASH_CMD_WRITE_TO_BUFFER);
                retcode = flash_status_check (info, sector,
@@ -791,16 +828,20 @@ static int flash_write_cfibuffer (flash_info_t * info, ulong dest, uchar * cp,
                        while (cnt-- > 0) {
                                switch (info->portwidth) {
                                case FLASH_CFI_8BIT:
-                                       *dst.cp++ = *src.cp++;
+                                       flash_write8(flash_read8(src), dst);
+                                       src += 1, dst += 1;
                                        break;
                                case FLASH_CFI_16BIT:
-                                       *dst.wp++ = *src.wp++;
+                                       flash_write16(flash_read16(src), dst);
+                                       src += 2, dst += 2;
                                        break;
                                case FLASH_CFI_32BIT:
-                                       *dst.lp++ = *src.lp++;
+                                       flash_write32(flash_read32(src), dst);
+                                       src += 4, dst += 4;
                                        break;
                                case FLASH_CFI_64BIT:
-                                       *dst.llp++ = *src.llp++;
+                                       flash_write64(flash_read64(src), dst);
+                                       src += 8, dst += 8;
                                        break;
                                default:
                                        return ERR_INVAL;
@@ -817,10 +858,6 @@ static int flash_write_cfibuffer (flash_info_t * info, ulong dest, uchar * cp,
 
        case CFI_CMDSET_AMD_STANDARD:
        case CFI_CMDSET_AMD_EXTENDED:
-               src.cp = cp;
-               dst.cp = (uchar *) dest;
-               sector = find_sector (info, dest);
-
                flash_unlock_seq(info,0);
                flash_write_cmd (info, sector, 0, AMD_CMD_WRITE_TO_BUFFER);
 
@@ -828,22 +865,34 @@ static int flash_write_cfibuffer (flash_info_t * info, ulong dest, uchar * cp,
                case FLASH_CFI_8BIT:
                        cnt = len;
                        flash_write_cmd (info, sector, 0,  (uchar) cnt - 1);
-                       while (cnt-- > 0) *dst.cp++ = *src.cp++;
+                       while (cnt-- > 0) {
+                               flash_write8(flash_read8(src), dst);
+                               src += 1, dst += 1;
+                       }
                        break;
                case FLASH_CFI_16BIT:
                        cnt = len >> 1;
                        flash_write_cmd (info, sector, 0,  (uchar) cnt - 1);
-                       while (cnt-- > 0) *dst.wp++ = *src.wp++;
+                       while (cnt-- > 0) {
+                               flash_write16(flash_read16(src), dst);
+                               src += 2, dst += 2;
+                       }
                        break;
                case FLASH_CFI_32BIT:
                        cnt = len >> 2;
                        flash_write_cmd (info, sector, 0,  (uchar) cnt - 1);
-                       while (cnt-- > 0) *dst.lp++ = *src.lp++;
+                       while (cnt-- > 0) {
+                               flash_write32(flash_read32(src), dst);
+                               src += 4, dst += 4;
+                       }
                        break;
                case FLASH_CFI_64BIT:
                        cnt = len >> 3;
                        flash_write_cmd (info, sector, 0,  (uchar) cnt - 1);
-                       while (cnt-- > 0) *dst.llp++ = *src.llp++;
+                       while (cnt-- > 0) {
+                               flash_write64(flash_read64(src), dst);
+                               src += 8, dst += 8;
+                       }
                        break;
                default:
                        return ERR_INVAL;