flash/nor: at91samd protection bits write fix

Flash protection set on a device with MANW=1 was lost after reset.
Since #2903 the driver honored MANW bit and issued Write Page command just
for main flash write. This change adds similar technique to
samd_modify_user_row().

Minor code improvements:
samd_check_error() returns error code corresponding to error type
instead of bool.

samd_check_error() does not clear STATUS register if no error bit is set.

Eliminated double error check in call sequence samd_issue_nvmctrl_command()
folowed by samd_check_error().

Missing error code ERROR_FLASH_PROTECTED added to src/flash/common.h.

Change-Id: Icf59ab8803305d0cb3170c8a5089b8f9828b99f8
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/3550
Tested-by: jenkins
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>

diff --git a/src/flash/common.h b/src/flash/common.h
index ce26fccd75b39632e9d457ec42128b562a05e221..4244f1360647c684aae958ee17c45213c53127b8 100644 (file)
--- a/src/flash/common.h
+++ b/src/flash/common.h
@@ -44,5 +44,6 @@ bool flash_driver_name_matches(const char *name, const char *expected);
 #define ERROR_FLASH_SECTOR_NOT_ERASED          (-906)
 #define ERROR_FLASH_BANK_NOT_PROBED                    (-907)
 #define ERROR_FLASH_OPER_UNSUPPORTED           (-908)
+#define ERROR_FLASH_PROTECTED                  (-909)
 
 #endif /* OPENOCD_FLASH_COMMON_H */

diff --git a/src/flash/nor/at91samd.c b/src/flash/nor/at91samd.c
index cdc43b8b3edd4edadd287a08e88a023abd95cd8d..2673b0eecadd858e1065557919106f4b2726f99f 100644 (file)
--- a/src/flash/nor/at91samd.c
+++ b/src/flash/nor/at91samd.c
@@ -423,39 +423,43 @@ static int samd_probe(struct flash_bank *bank)
        return ERROR_OK;
 }
 
-static bool samd_check_error(struct target *target)
+static int samd_check_error(struct target *target)
 {
-       int ret;
-       bool error;
+       int ret, ret2;
        uint16_t status;
 
        ret = target_read_u16(target,
                        SAMD_NVMCTRL + SAMD_NVMCTRL_STATUS, &status);
        if (ret != ERROR_OK) {
                LOG_ERROR("Can't read NVM status");
-               return true;
+               return ret;
        }
 
-       if (status & 0x001C) {
-               if (status & (1 << 4)) /* NVME */
-                       LOG_ERROR("SAMD: NVM Error");
-               if (status & (1 << 3)) /* LOCKE */
-                       LOG_ERROR("SAMD: NVM lock error");
-               if (status & (1 << 2)) /* PROGE */
-                       LOG_ERROR("SAMD: NVM programming error");
+       if ((status & 0x001C) == 0)
+               return ERROR_OK;
 
-               error = true;
-       } else {
-               error = false;
+       if (status & (1 << 4)) { /* NVME */
+               LOG_ERROR("SAMD: NVM Error");
+               ret = ERROR_FLASH_OPERATION_FAILED;
+       }
+
+       if (status & (1 << 3)) { /* LOCKE */
+               LOG_ERROR("SAMD: NVM lock error");
+               ret = ERROR_FLASH_PROTECTED;
+       }
+
+       if (status & (1 << 2)) { /* PROGE */
+               LOG_ERROR("SAMD: NVM programming error");
+               ret = ERROR_FLASH_OPER_UNSUPPORTED;
        }
 
        /* Clear the error conditions by writing a one to them */
-       ret = target_write_u16(target,
+       ret2 = target_write_u16(target,
                        SAMD_NVMCTRL + SAMD_NVMCTRL_STATUS, status);
-       if (ret != ERROR_OK)
+       if (ret2 != ERROR_OK)
                LOG_ERROR("Can't clear NVM error conditions");
 
-       return error;
+       return ret;
 }
 
 static int samd_issue_nvmctrl_command(struct target *target, uint16_t cmd)
@@ -474,10 +478,7 @@ static int samd_issue_nvmctrl_command(struct target *target, uint16_t cmd)
                return res;
 
        /* Check to see if the NVM command resulted in an error condition. */
-       if (samd_check_error(target))
-               return ERROR_FAIL;
-
-       return ERROR_OK;
+       return samd_check_error(target);
 }
 
 static int samd_erase_row(struct target *target, uint32_t address)
@@ -531,12 +532,19 @@ static int samd_modify_user_row(struct target *target, uint32_t value,
                uint8_t startb, uint8_t endb)
 {
        int res;
+       uint32_t nvm_ctrlb;
+       bool manual_wp = true;
 
        if (is_user_row_reserved_bit(startb) || is_user_row_reserved_bit(endb)) {
                LOG_ERROR("Can't modify bits in the requested range");
                return ERROR_FAIL;
        }
 
+       /* Check if we need to do manual page write commands */
+       res = target_read_u32(target, SAMD_NVMCTRL + SAMD_NVMCTRL_CTRLB, &nvm_ctrlb);
+       if (res == ERROR_OK)
+               manual_wp = (nvm_ctrlb & SAMD_NVM_CTRLB_MANW) != 0;
+
        /* Retrieve the MCU's page size, in bytes. This is also the size of the
         * entire User Row. */
        uint32_t page_size;
@@ -559,8 +567,8 @@ static int samd_modify_user_row(struct target *target, uint32_t value,
        if (!buf)
                return ERROR_FAIL;
 
-       /* Read the user row (comprising one page) by half-words. */
-       res = target_read_memory(target, SAMD_USER_ROW, 2, page_size / 2, buf);
+       /* Read the user row (comprising one page) by words. */
+       res = target_read_memory(target, SAMD_USER_ROW, 4, page_size / 4, buf);
        if (res != ERROR_OK)
                goto out_user_row;
 
@@ -579,20 +587,18 @@ static int samd_modify_user_row(struct target *target, uint32_t value,
        /* Modify */
        buf_set_u32(buf, startb, endb - startb + 1, value);
 
-       /* Write the page buffer back out to the target.  A Flash write will be
-        * triggered automatically. */
+       /* Write the page buffer back out to the target. */
        res = target_write_memory(target, SAMD_USER_ROW, 4, page_size / 4, buf);
        if (res != ERROR_OK)
                goto out_user_row;
 
-       if (samd_check_error(target)) {
-               res = ERROR_FAIL;
-               goto out_user_row;
+       if (manual_wp) {
+               /* Trigger flash write */
+               res = samd_issue_nvmctrl_command(target, SAMD_NVM_CMD_WAP);
+       } else {
+               res = samd_check_error(target);
        }
 
-       /* Success */
-       res = ERROR_OK;
-
 out_user_row:
        free(buf);
 
@@ -784,18 +790,15 @@ static int samd_write(struct flash_bank *bank, const uint8_t *buffer,
                 * then issue CMD_WP always */
                if (manual_wp || pg_offset + 4 * nw < chip->page_size) {
                        res = samd_issue_nvmctrl_command(bank->target, SAMD_NVM_CMD_WP);
-                       if (res != ERROR_OK) {
-                               LOG_ERROR("%s: %d", __func__, __LINE__);
-                               goto free_pb;
-                       }
-               }
+               } else {
+                       /* Access through AHB is stalled while flash is being programmed */
+                       usleep(200);
 
-               /* Access through AHB is stalled while flash is being programmed */
-               usleep(200);
+                       res = samd_check_error(bank->target);
+               }
 
-               if (samd_check_error(bank->target)) {
+               if (res != ERROR_OK) {
                        LOG_ERROR("%s: write failed at address 0x%08" PRIx32, __func__, address);
-                       res = ERROR_FAIL;
                        goto free_pb;
                }