From: Keith Packard <keithp@keithp.com>
Date: Wed, 29 Aug 2012 01:10:34 +0000 (-0700)
Subject: altos: Explicitly erase memory in STM eeprom driver.
X-Git-Tag: 1.1~58
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=eb1a9a8c3f3d3993d5986925bc4ad112c2bbc119

altos: Explicitly erase memory in STM eeprom driver.

This seems to make the STM32L152 happier

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 1e51b417..5a75a97d 100644
--- a/src/stm/ao_eeprom_stm.c
+++ b/src/stm/ao_eeprom_stm.c
@@ -82,19 +82,30 @@ ao_intflash_lock(void)
 	stm_flash.pecr |= (1 << STM_FLASH_PECR_PELOCK);
 }
 
+static void
+ao_intflash_wait(void)
+{
+	/* Wait for the flash unit to go idle */
+	while (stm_flash.sr & (1 << STM_FLASH_SR_BSY))
+		;
+}
+
 static void
 ao_intflash_write32(uint16_t pos, uint32_t w)
 {
-	uint32_t	*addr;
+	volatile uint32_t	*addr;
 
 	addr = (uint32_t *) (stm_eeprom + pos);
 
-	/* Write a word to a valid address in the data EEPROM */
-	*addr = w;
+	/* Erase previous word */
+	*addr = 0;
+	ao_intflash_wait();
 
-	/* Wait for the flash unit to go idle */
-	while (stm_flash.sr & (1 << STM_FLASH_SR_BSY))
-		;
+	if (w) {
+		/* Write a word to a valid address in the data EEPROM */
+		*addr = w;
+		ao_intflash_wait();
+	}
 }
 
 static void
@@ -182,6 +193,7 @@ ao_storage_setup(void)
 void
 ao_storage_device_info(void) __reentrant
 {
+	uint8_t	i;
 	printf ("Using internal flash\n");
 }