stm32f1x: improve variable naming and avoid potential divide-by-zero

Don't call a variable num_pages if it holds the flash size. Also rearrange
flash size to num_pages calculation to avoid divide-by-zero if there will
be a device with < 1024 byte pages someday.

Change-Id: I2febea39694a2f9750de141f52ec88ae1599c086
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-on: http://openocd.zylin.com/211
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

diff --git a/src/flash/nor/stm32f1x.c b/src/flash/nor/stm32f1x.c
index 0678ce36dc8641214df0696c32cd32c00b1a1f32..8e0fda7e8a43118b494141d2b4f1f4eb6be117a9 100644 (file)
--- a/src/flash/nor/stm32f1x.c
+++ b/src/flash/nor/stm32f1x.c
@@ -955,7 +955,7 @@ static int stm32x_probe(struct flash_bank *bank)
        struct target *target = bank->target;
        struct stm32x_flash_bank *stm32x_info = bank->driver_priv;
        int i;
-       uint16_t num_pages;
+       uint16_t flash_size_in_kb;
        uint32_t device_id;
        int page_size;
        uint32_t base_address = 0x08000000;
@@ -970,12 +970,12 @@ static int stm32x_probe(struct flash_bank *bank)
        LOG_INFO("device id = 0x%08" PRIx32 "", device_id);
 
        /* get flash size from target. */
-       retval = target_read_u16(target, 0x1FFFF7E0, &num_pages);
+       retval = target_read_u16(target, 0x1FFFF7E0, &flash_size_in_kb);
        if (retval != ERROR_OK)
        {
                LOG_WARNING("failed reading flash size, default to max target family");
                /* failed reading flash size, default to max target family */
-               num_pages = 0xffff;
+               flash_size_in_kb = 0xffff;
        }
 
        if ((device_id & 0x7ff) == 0x410)
@@ -986,11 +986,11 @@ static int stm32x_probe(struct flash_bank *bank)
                stm32x_info->ppage_size = 4;
 
                /* check for early silicon */
-               if (num_pages == 0xffff)
+               if (flash_size_in_kb == 0xffff)
                {
                        /* number of sectors incorrect on revA */
                        LOG_WARNING("STM32 flash size failed, probe inaccurate - assuming 128k flash");
-                       num_pages = 128;
+                       flash_size_in_kb = 128;
                }
        }
        else if ((device_id & 0x7ff) == 0x412)
@@ -1001,11 +1001,11 @@ static int stm32x_probe(struct flash_bank *bank)
                stm32x_info->ppage_size = 4;
 
                /* check for early silicon */
-               if (num_pages == 0xffff)
+               if (flash_size_in_kb == 0xffff)
                {
                        /* number of sectors incorrect on revA */
                        LOG_WARNING("STM32 flash size failed, probe inaccurate - assuming 32k flash");
-                       num_pages = 32;
+                       flash_size_in_kb = 32;
                }
        }
        else if ((device_id & 0x7ff) == 0x414)
@@ -1016,11 +1016,11 @@ static int stm32x_probe(struct flash_bank *bank)
                stm32x_info->ppage_size = 2;
 
                /* check for early silicon */
-               if (num_pages == 0xffff)
+               if (flash_size_in_kb == 0xffff)
                {
                        /* number of sectors incorrect on revZ */
                        LOG_WARNING("STM32 flash size failed, probe inaccurate - assuming 512k flash");
-                       num_pages = 512;
+                       flash_size_in_kb = 512;
                }
        }
        else if ((device_id & 0x7ff) == 0x418)
@@ -1031,11 +1031,11 @@ static int stm32x_probe(struct flash_bank *bank)
                stm32x_info->ppage_size = 2;
 
                /* check for early silicon */
-               if (num_pages == 0xffff)
+               if (flash_size_in_kb == 0xffff)
                {
                        /* number of sectors incorrect on revZ */
                        LOG_WARNING("STM32 flash size failed, probe inaccurate - assuming 256k flash");
-                       num_pages = 256;
+                       flash_size_in_kb = 256;
                }
        }
        else if ((device_id & 0x7ff) == 0x420)
@@ -1046,11 +1046,11 @@ static int stm32x_probe(struct flash_bank *bank)
                stm32x_info->ppage_size = 4;
 
                /* check for early silicon */
-               if (num_pages == 0xffff)
+               if (flash_size_in_kb == 0xffff)
                {
                        /* number of sectors may be incorrrect on early silicon */
                        LOG_WARNING("STM32 flash size failed, probe inaccurate - assuming 128k flash");
-                       num_pages = 128;
+                       flash_size_in_kb = 128;
                }
        }
        else if ((device_id & 0x7ff) == 0x428)
@@ -1061,11 +1061,11 @@ static int stm32x_probe(struct flash_bank *bank)
                stm32x_info->ppage_size = 4;
 
                /* check for early silicon */
-               if (num_pages == 0xffff)
+               if (flash_size_in_kb == 0xffff)
                {
                        /* number of sectors may be incorrrect on early silicon */
                        LOG_WARNING("STM32 flash size failed, probe inaccurate - assuming 128k flash");
-                       num_pages = 128;
+                       flash_size_in_kb = 128;
                }
        }
 
@@ -1078,22 +1078,22 @@ static int stm32x_probe(struct flash_bank *bank)
                stm32x_info->has_dual_banks = true;
 
                /* check for early silicon */
-               if (num_pages == 0xffff)
+               if (flash_size_in_kb == 0xffff)
                {
                        /* number of sectors may be incorrrect on early silicon */
                        LOG_WARNING("STM32 flash size failed, probe inaccurate - assuming 1024k flash");
-                       num_pages = 1024;
+                       flash_size_in_kb = 1024;
                }
 
                /* split reported size into matching bank */
                if (bank->base != 0x08080000)
                {
                        /* bank 0 will be fixed 512k */
-                       num_pages = 512;
+                       flash_size_in_kb = 512;
                }
                else
                {
-                       num_pages -= 512;
+                       flash_size_in_kb -= 512;
                        /* bank1 also uses a register offset */
                        stm32x_info->register_base = FLASH_REG_BASE_B1;
                        base_address = 0x08080000;
@@ -1105,13 +1105,13 @@ static int stm32x_probe(struct flash_bank *bank)
                return ERROR_FAIL;
        }
 
-       LOG_INFO("flash size = %dkbytes", num_pages);
+       LOG_INFO("flash size = %dkbytes", flash_size_in_kb);
 
-       /* did we assign # of pages? */
-       assert(num_pages != 0xffff);
+       /* did we assign flash size? */
+       assert(flash_size_in_kb != 0xffff);
 
        /* calculate numbers of pages */
-       num_pages /= (page_size / 1024);
+       int num_pages = flash_size_in_kb * 1024 / page_size;
 
        /* check that calculation result makes sense */
        assert(num_pages > 0);