From 89747f81f22084b255f35d92f709facd3b4553a1 Mon Sep 17 00:00:00 2001 From: Antonio Borneo Date: Mon, 19 Apr 2010 16:40:08 +0800 Subject: [PATCH] NOR/CFI: simplify bufferwsize computation Review and simplify computation of bufferwsize. Add comments about variables' meaning. The same code is present 3 times in the file. Current patch updates all the 3 instances. Step 1) Replace "switch(bank->chip_width) {...}". Illegal values of bank->chip_width are already dropped. For legal values, the code is equivalent to: bufferwsize = buffersize / bank->chip_width; Step 2) The above code replacement plus the following line: bufferwsize /= (bank->bus_width / bank->chip_width); is merged in a single formula: bufferwsize = (buffersize / bank->chip_width) / (bank->bus_width / bank->chip_width); and simplified as: bufferwsize = buffersize / bank->bus_width; Signed-off-by: Antonio Borneo --- src/flash/nor/cfi.c | 49 +++++++++------------------------------------ 1 file changed, 10 insertions(+), 39 deletions(-) diff --git a/src/flash/nor/cfi.c b/src/flash/nor/cfi.c index ba2d9095f..f2ea947ad 100644 --- a/src/flash/nor/cfi.c +++ b/src/flash/nor/cfi.c @@ -1604,9 +1604,11 @@ static int cfi_intel_write_words(struct flash_bank *bank, uint8_t *word, uint32_ struct target *target = bank->target; /* Calculate buffer size and boundary mask */ + /* buffersize is (buffer size per chip) * (number of chips) */ + /* bufferwsize is buffersize in words */ uint32_t buffersize = (1UL << cfi_info->max_buf_write_size) * (bank->bus_width / bank->chip_width); uint32_t buffermask = buffersize-1; - uint32_t bufferwsize; + uint32_t bufferwsize = buffersize / bank->bus_width; /* Check for valid range */ if (address & buffermask) @@ -1615,18 +1617,6 @@ static int cfi_intel_write_words(struct flash_bank *bank, uint8_t *word, uint32_ bank->base, address, cfi_info->max_buf_write_size); return ERROR_FLASH_OPERATION_FAILED; } - switch (bank->chip_width) - { - case 4 : bufferwsize = buffersize / 4; break; - case 2 : bufferwsize = buffersize / 2; break; - case 1 : bufferwsize = buffersize; break; - default: - LOG_ERROR("Unsupported chip width %d", bank->chip_width); - return ERROR_FLASH_OPERATION_FAILED; - } - - bufferwsize/=(bank->bus_width / bank->chip_width); - /* Check for valid size */ if (wordcount > bufferwsize) @@ -1733,9 +1723,11 @@ static int cfi_spansion_write_words(struct flash_bank *bank, uint8_t *word, uint struct cfi_spansion_pri_ext *pri_ext = cfi_info->pri_ext; /* Calculate buffer size and boundary mask */ + /* buffersize is (buffer size per chip) * (number of chips) */ + /* bufferwsize is buffersize in words */ uint32_t buffersize = (1UL << cfi_info->max_buf_write_size) * (bank->bus_width / bank->chip_width); uint32_t buffermask = buffersize-1; - uint32_t bufferwsize; + uint32_t bufferwsize = buffersize / bank->bus_width; /* Check for valid range */ if (address & buffermask) @@ -1743,17 +1735,6 @@ static int cfi_spansion_write_words(struct flash_bank *bank, uint8_t *word, uint LOG_ERROR("Write address at base 0x%" PRIx32 ", address %" PRIx32 " not aligned to 2^%d boundary", bank->base, address, cfi_info->max_buf_write_size); return ERROR_FLASH_OPERATION_FAILED; } - switch (bank->chip_width) - { - case 4 : bufferwsize = buffersize / 4; break; - case 2 : bufferwsize = buffersize / 2; break; - case 1 : bufferwsize = buffersize; break; - default: - LOG_ERROR("Unsupported chip width %d", bank->chip_width); - return ERROR_FLASH_OPERATION_FAILED; - } - - bufferwsize/=(bank->bus_width / bank->chip_width); /* Check for valid size */ if (wordcount > bufferwsize) @@ -1950,22 +1931,12 @@ static int cfi_write(struct flash_bank *bank, uint8_t *buffer, uint32_t offset, { if (retval == ERROR_TARGET_RESOURCE_NOT_AVAILABLE) { - //adjust buffersize for chip width + /* Calculate buffer size and boundary mask */ + /* buffersize is (buffer size per chip) * (number of chips) */ + /* bufferwsize is buffersize in words */ uint32_t buffersize = (1UL << cfi_info->max_buf_write_size) * (bank->bus_width / bank->chip_width); uint32_t buffermask = buffersize-1; - uint32_t bufferwsize; - - switch (bank->chip_width) - { - case 4 : bufferwsize = buffersize / 4; break; - case 2 : bufferwsize = buffersize / 2; break; - case 1 : bufferwsize = buffersize; break; - default: - LOG_ERROR("Unsupported chip width %d", bank->chip_width); - return ERROR_FLASH_OPERATION_FAILED; - } - - bufferwsize/=(bank->bus_width / bank->chip_width); + uint32_t bufferwsize = buffersize / bank->bus_width; /* fall back to memory writes */ while (count >= (uint32_t)bank->bus_width)