From: Keith Packard <keithp@keithp.com>
Date: Thu, 28 Mar 2013 01:43:42 +0000 (-0700)
Subject: altos: Use FTDW, clear DATA bit. Disable backup write protection
X-Git-Tag: altosdroid_v1.2-1~73
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=985cd22b941415b1ae2709ae1ab6b60c3d815ec1

altos: Use FTDW, clear DATA bit. Disable backup write protection

The newer(?) chips in telegps didn't like the previous programming
scheme, so go back to fixed time for write, which does an implicit
erase before every write. Also clear the DATA bit, which is only
needed for double word erase/programming.

Signed-off-by: Keith Packard <keithp@keithp.com>
---

diff --git a/src/stm/ao_eeprom_stm.c b/src/stm/ao_eeprom_stm.c
index 5a75a97d..58783f1a 100644
--- a/src/stm/ao_eeprom_stm.c
+++ b/src/stm/ao_eeprom_stm.c
@@ -55,10 +55,16 @@ ao_storage_erase(ao_pos_t pos) __reentrant
 static void
 ao_intflash_unlock(void)
 {
+	/* Disable backup write protection */
+	stm_pwr.cr |= (1 << STM_PWR_CR_DBP);
+
 	/* Unlock Data EEPROM and FLASH_PECR register */
 	stm_flash.pekeyr = STM_FLASH_PEKEYR_PEKEY1;
 	stm_flash.pekeyr = STM_FLASH_PEKEYR_PEKEY2;
 
+	if (stm_flash.pecr & (1 << STM_FLASH_PECR_PELOCK))
+		printf ("eeprom unlock failed\n");
+
 	/* Configure the FTDW bit (FLASH_PECR[8]) to execute
 	 * word write, whatever the previous value of the word
 	 * being written to
@@ -68,8 +74,8 @@ ao_intflash_unlock(void)
 			  (0 << STM_FLASH_PECR_EOPIE) |
 			  (0 << STM_FLASH_PECR_FPRG) |
 			  (0 << STM_FLASH_PECR_ERASE) |
-			  (0 << STM_FLASH_PECR_FTDW) |
-			  (1 << STM_FLASH_PECR_DATA) |
+			  (1 << STM_FLASH_PECR_FTDW) |
+			  (0 << STM_FLASH_PECR_DATA) |
 			  (0 << STM_FLASH_PECR_PROG) |
 			  (0 << STM_FLASH_PECR_OPTLOCK) |
 			  (0 << STM_FLASH_PECR_PRGLOCK) |
@@ -97,15 +103,9 @@ ao_intflash_write32(uint16_t pos, uint32_t w)
 
 	addr = (uint32_t *) (stm_eeprom + pos);
 
-	/* Erase previous word */
-	*addr = 0;
+	/* Write a word to a valid address in the data EEPROM */
+	*addr = w;
 	ao_intflash_wait();
-
-	if (w) {
-		/* Write a word to a valid address in the data EEPROM */
-		*addr = w;
-		ao_intflash_wait();
-	}
 }
 
 static void