Merge branch 'master'

[fw/altos] / src / samd21 / ao_flash_samd21.c

diff --git a/src/samd21/ao_flash_samd21.c b/src/samd21/ao_flash_samd21.c
new file mode 100644 (file)
index 0000000..502ff35
--- /dev/null
+++ b/src/samd21/ao_flash_samd21.c
@@ -0,0 +1,150 @@
+/*
+ * Copyright © 2019 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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>
+#include <stdio.h>
+
+/* Erase rows are four pages */
+static uint32_t
+samd21_nvmctrl_row_size(void)
+{
+       return samd21_nvmctrl_page_size() * 4;
+}
+
+/* size of a lock region. That's just total flash size / 16 */
+static uint32_t
+samd21_nvmctrl_lock_region(void)
+{
+       return samd21_flash_size() >> 4;
+}
+
+/* Find the bit index of an address within the lock word */
+static uint8_t
+ao_flash_lock_region_bit(void *addr)
+{
+       uint32_t lock_region = samd21_nvmctrl_lock_region();
+       uintptr_t a = (uintptr_t) addr;
+
+       while (lock_region) {
+               a >>= 1;
+               lock_region >>= 1;
+       }
+
+       return (uint8_t) a;
+}
+
+static uint8_t
+ao_flash_is_locked(void *addr)
+{
+       return (samd21_nvmctrl.lock >> ao_flash_lock_region_bit(addr)) & 1;
+}
+
+/* Execute a single flash operation, waiting for it to complete. This
+ * bit of code must be in ram
+ */
+static void __attribute__ ((section(".sdata2.flash"), noinline))
+_ao_flash_execute(uint16_t cmd)
+{
+       while ((samd21_nvmctrl.intflag & (1 << SAMD21_NVMCTRL_INTFLAG_READY)) == 0)
+               ;
+       samd21_nvmctrl.ctrla = ((cmd << SAMD21_NVMCTRL_CTRLA_CMD) |
+                               (SAMD21_NVMCTRL_CTRLA_CMDEX_KEY << SAMD21_NVMCTRL_CTRLA_CMDEX));
+       while ((samd21_nvmctrl.intflag & (1 << SAMD21_NVMCTRL_INTFLAG_READY)) == 0)
+               ;
+       samd21_nvmctrl.intflag = ((1 << SAMD21_NVMCTRL_INTFLAG_READY) |
+                                 (1 << SAMD21_NVMCTRL_INTFLAG_ERROR));
+}
+
+/* Set the address of the next flash operation */
+static void
+_ao_flash_set_addr(void *addr)
+{
+       while ((samd21_nvmctrl.intflag & (1 << SAMD21_NVMCTRL_INTFLAG_READY)) == 0)
+               ;
+       samd21_nvmctrl.addr = ((uint32_t) addr) >> 1;
+       while ((samd21_nvmctrl.intflag & (1 << SAMD21_NVMCTRL_INTFLAG_READY)) == 0)
+               ;
+}
+
+/* Unlock a region of flash */
+static void
+_ao_flash_unlock(void *addr)
+{
+       if (!ao_flash_is_locked(addr))
+               return;
+
+       _ao_flash_set_addr(addr);
+       _ao_flash_execute(SAMD21_NVMCTRL_CTRLA_CMD_UR);
+}
+
+/* Erase a row of flash */
+static void
+_ao_flash_erase_row(void *row)
+{
+       _ao_flash_unlock(row);
+       _ao_flash_set_addr(row);
+       _ao_flash_execute(SAMD21_NVMCTRL_CTRLA_CMD_ER);
+}
+
+void
+ao_flash_erase_page(uint32_t *page)
+{
+       uint8_t *row = (uint8_t *) page;
+       uint32_t row_size = samd21_nvmctrl_row_size();
+       uint32_t rows = (row_size + 255) / 256;
+
+       if ((uintptr_t) page & (row_size - 1))
+               return;
+
+       ao_arch_block_interrupts();
+
+       if (((uintptr_t) row & (row_size - 1)) == 0) {
+               while (rows--) {
+                       _ao_flash_erase_row(row);
+                       row += row_size;
+               }
+       }
+
+       ao_arch_release_interrupts();
+}
+
+void
+ao_flash_page(uint32_t *page, uint32_t *src)
+{
+       uint32_t        page_shift = samd21_nvmctrl_page_shift();
+       uint32_t        pages = 256 >> page_shift;
+       uint32_t        i;
+       uint32_t        per_page = 1 << (page_shift - 2);
+
+       ao_flash_erase_page(page);
+
+       ao_arch_block_interrupts();
+
+       while(pages--) {
+               /* Clear write buffer */
+               _ao_flash_execute(SAMD21_NVMCTRL_CTRLA_CMD_PBC);
+               _ao_flash_set_addr(page);
+               for (i = 0; i < per_page; i++)
+                       *page++ = *src++;
+               _ao_flash_execute(SAMD21_NVMCTRL_CTRLA_CMD_WP);
+       }
+
+       ao_arch_release_interrupts();
+}
+