altos: Add self-flash support for STM32F042 processor

[fw/altos] / src / stmf0 / ao_flash_stm.c

diff --git a/src/stmf0/ao_flash_stm.c b/src/stmf0/ao_flash_stm.c
new file mode 100644 (file)
index 0000000..5fe0e61
--- /dev/null
+++ b/src/stmf0/ao_flash_stm.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright © 2013 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+#include <ao_flash.h>
+
+static uint8_t
+ao_flash_is_locked(void)
+{
+       return (stm_flash.cr & (1 << STM_FLASH_CR_LOCK)) != 0;
+}
+
+static void
+ao_flash_unlock(void)
+{
+       if (!ao_flash_is_locked())
+               return;
+
+       /* Unlock FLASH_CR register */
+       stm_flash.keyr = STM_FLASH_KEYR_KEY1;
+       stm_flash.keyr = STM_FLASH_KEYR_KEY2;
+       if (ao_flash_is_locked())
+               ao_panic(AO_PANIC_FLASH);
+}
+
+static void
+ao_flash_lock(void)
+{
+       stm_flash.cr |= (1 << STM_FLASH_CR_LOCK);
+}
+
+static void
+ao_flash_wait_bsy(void)
+{
+       while (stm_flash.sr & (1 << STM_FLASH_SR_BSY))
+               ;
+}
+
+static void __attribute__ ((section(".ramtext"),noinline))
+_ao_flash_erase_page(uint32_t *page)
+{
+       stm_flash.cr |= (1 << STM_FLASH_CR_PER);
+
+       stm_flash.ar = (uintptr_t) page;
+
+       stm_flash.cr |= (1 << STM_FLASH_CR_STRT);
+
+       ao_flash_wait_bsy();
+
+       stm_flash.cr &= ~(1 << STM_FLASH_CR_PER);
+}
+
+static uint32_t
+stm_flash_page_size(void)
+{
+       uint16_t        dev_id = stm_dev_id();
+
+       switch (dev_id) {
+       case 0x440:     /* stm32f05x */
+       case 0x444:     /* stm32f03x */
+       case 0x445:     /* stm32f04x */
+               return 1024;
+       case 0x442:     /* stm32f09x */
+       case 0x448:     /* stm32f07x */
+               return 2048;
+       }
+       ao_panic(AO_PANIC_FLASH);
+       return 0;
+}
+
+void
+ao_flash_erase_page(uint32_t *page)
+{
+       /* Erase the whole page at the start. This assumes we'll be flashing things
+        * in memory order
+        */
+
+       if ((uintptr_t) page & (stm_flash_page_size() - 1))
+               return;
+
+       ao_arch_block_interrupts();
+       ao_flash_unlock();
+
+       _ao_flash_erase_page(page);
+
+       ao_flash_lock();
+       ao_arch_release_interrupts();
+}
+
+static void __attribute__ ((section(".ramtext"), noinline))
+_ao_flash_page(uint16_t *dst, uint16_t *src)
+{
+       uint8_t         i;
+
+       stm_flash.cr |= (1 << STM_FLASH_CR_PG);
+
+       for (i = 0; i < 128; i++) {
+               *dst++ = *src++;
+               ao_flash_wait_bsy();
+       }
+
+       stm_flash.cr &= ~(1 << STM_FLASH_CR_PG);
+}
+
+void
+ao_flash_page(uint32_t *page, uint32_t *src)
+{
+       ao_flash_erase_page(page);
+
+       ao_arch_block_interrupts();
+       ao_flash_unlock();
+
+       _ao_flash_page((uint16_t *) page, (uint16_t *) src);
+
+       ao_flash_lock();
+       ao_arch_release_interrupts();
+}