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   1 /*
   2  * Copyright © 2013 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  16  */
  17
  18 #include <ao.h>
  19 #include <ao_flash.h>
  20
  21 static uint8_t
  22 ao_flash_pecr_is_locked(void)
  23 {
  24         return (stm_flash.pecr & (1 << STM_FLASH_PECR_PELOCK)) != 0;
  25 }
  26
  27 static uint8_t
  28 ao_flash_pgr_is_locked(void)
  29 {
  30         return (stm_flash.pecr & (1 << STM_FLASH_PECR_PRGLOCK)) != 0;
  31 }
  32
  33 static void
  34 ao_flash_pecr_unlock(void)
  35 {
  36         if (!ao_flash_pecr_is_locked())
  37                 return;
  38
  39         /* Unlock Data EEPROM and FLASH_PECR register */
  40         stm_flash.pekeyr = STM_FLASH_PEKEYR_PEKEY1;
  41         stm_flash.pekeyr = STM_FLASH_PEKEYR_PEKEY2;
  42         if (ao_flash_pecr_is_locked())
  43                 ao_panic(AO_PANIC_FLASH);
  44 }
  45
  46 static void
  47 ao_flash_pgr_unlock(void)
  48 {
  49         if (!ao_flash_pgr_is_locked())
  50                 return;
  51
  52         /* Unlock program memory */
  53         stm_flash.prgkeyr = STM_FLASH_PRGKEYR_PRGKEY1;
  54         stm_flash.prgkeyr = STM_FLASH_PRGKEYR_PRGKEY2;
  55         if (ao_flash_pgr_is_locked())
  56                 ao_panic(AO_PANIC_FLASH);
  57 }
  58
  59 static void
  60 ao_flash_lock(void)
  61 {
  62         stm_flash.pecr |= (1 << STM_FLASH_PECR_OPTLOCK) | (1 << STM_FLASH_PECR_PRGLOCK) | (1 << STM_FLASH_PECR_PELOCK);
  63 }
  64
  65 static void
  66 ao_flash_wait_bsy(void)
  67 {
  68         while (stm_flash.sr & (1 << STM_FLASH_SR_BSY))
  69                 ;
  70 }
  71
  72 static void __attribute__ ((section(".text.ram"),noinline))
  73 _ao_flash_erase_page(uint32_t *page)
  74 {
  75         stm_flash.pecr |= (1 << STM_FLASH_PECR_ERASE) | (1 << STM_FLASH_PECR_PROG);
  76
  77         *page = 0x00000000;
  78
  79         while (stm_flash.sr & (1 << STM_FLASH_SR_BSY))
  80                 ;
  81 }
  82
  83 void
  84 ao_flash_erase_page(uint32_t *page)
  85 {
  86         ao_flash_pecr_unlock();
  87         ao_flash_pgr_unlock();
  88
  89         _ao_flash_erase_page(page);
  90
  91         ao_flash_lock();
  92 }
  93
  94 static void __attribute__ ((section(".text.ram"), noinline))
  95 _ao_flash_half_page(uint32_t *dst, uint32_t *src)
  96 {
  97         uint8_t         i;
  98
  99         stm_flash.pecr |= (1 << STM_FLASH_PECR_FPRG);
 100         stm_flash.pecr |= (1 << STM_FLASH_PECR_PROG);
 101
 102         while (stm_flash.sr & (1 << STM_FLASH_SR_BSY))
 103                 ;
 104
 105         for (i = 0; i < 32; i++) {
 106                 *dst++ = *src++;
 107         }
 108
 109         while (stm_flash.sr & (1 << STM_FLASH_SR_BSY))
 110                 ;
 111 }
 112
 113 void
 114 ao_flash_page(uint32_t *page, uint32_t *src)
 115 {
 116         uint8_t         h;
 117
 118         ao_flash_erase_page(page);
 119         ao_flash_pecr_unlock();
 120         ao_flash_pgr_unlock();
 121         for (h = 0; h < 2; h++) {
 122                 _ao_flash_half_page(page, src);
 123                 page += 32;
 124                 src += 32;
 125         }
 126         ao_flash_lock();
 127 }