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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; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  17  */
  18
  19 #include <ao.h>
  20 #include <ao_flash.h>
  21
  22 static uint8_t
  23 ao_flash_pecr_is_locked(void)
  24 {
  25         return (stm_flash.pecr & (1 << STM_FLASH_PECR_PELOCK)) != 0;
  26 }
  27
  28 static uint8_t
  29 ao_flash_pgr_is_locked(void)
  30 {
  31         return (stm_flash.pecr & (1 << STM_FLASH_PECR_PRGLOCK)) != 0;
  32 }
  33
  34 static void
  35 ao_flash_pecr_unlock(void)
  36 {
  37         if (!ao_flash_pecr_is_locked())
  38                 return;
  39
  40         /* Unlock Data EEPROM and FLASH_PECR register */
  41         stm_flash.pekeyr = STM_FLASH_PEKEYR_PEKEY1;
  42         stm_flash.pekeyr = STM_FLASH_PEKEYR_PEKEY2;
  43         if (ao_flash_pecr_is_locked())
  44                 ao_panic(AO_PANIC_FLASH);
  45 }
  46
  47 static void
  48 ao_flash_pgr_unlock(void)
  49 {
  50         if (!ao_flash_pgr_is_locked())
  51                 return;
  52
  53         /* Unlock program memory */
  54         stm_flash.prgkeyr = STM_FLASH_PRGKEYR_PRGKEY1;
  55         stm_flash.prgkeyr = STM_FLASH_PRGKEYR_PRGKEY2;
  56         if (ao_flash_pgr_is_locked())
  57                 ao_panic(AO_PANIC_FLASH);
  58 }
  59
  60 static void
  61 ao_flash_lock(void)
  62 {
  63         stm_flash.pecr |= (1 << STM_FLASH_PECR_OPTLOCK) | (1 << STM_FLASH_PECR_PRGLOCK) | (1 << STM_FLASH_PECR_PELOCK);
  64 }
  65
  66 static void
  67 ao_flash_wait_bsy(void)
  68 {
  69         while (stm_flash.sr & (1 << STM_FLASH_SR_BSY))
  70                 ;
  71 }
  72
  73 static void __attribute__ ((section(".ramtext"),noinline))
  74 _ao_flash_erase_page(uint32_t *page)
  75 {
  76         stm_flash.pecr |= (1 << STM_FLASH_PECR_ERASE) | (1 << STM_FLASH_PECR_PROG);
  77
  78         *page = 0x00000000;
  79
  80         ao_flash_wait_bsy();
  81 }
  82
  83 void
  84 ao_flash_erase_page(uint32_t *page)
  85 {
  86         ao_arch_block_interrupts();
  87         ao_flash_pecr_unlock();
  88         ao_flash_pgr_unlock();
  89
  90         _ao_flash_erase_page(page);
  91
  92         ao_flash_lock();
  93         ao_arch_release_interrupts();
  94 }
  95
  96 static void __attribute__ ((section(".ramtext"), noinline))
  97 _ao_flash_half_page(uint32_t *dst, uint32_t *src)
  98 {
  99         uint8_t         i;
 100
 101         stm_flash.pecr |= (1 << STM_FLASH_PECR_FPRG);
 102         stm_flash.pecr |= (1 << STM_FLASH_PECR_PROG);
 103
 104         ao_flash_wait_bsy();
 105
 106         for (i = 0; i < 32; i++) {
 107                 *dst++ = *src++;
 108         }
 109
 110         while (stm_flash.sr & (1 << STM_FLASH_SR_BSY))
 111                 ;
 112 }
 113
 114 void
 115 ao_flash_page(uint32_t *page, uint32_t *src)
 116 {
 117         uint8_t         h;
 118
 119         ao_flash_erase_page(page);
 120
 121         ao_arch_block_interrupts();
 122         ao_flash_pecr_unlock();
 123         ao_flash_pgr_unlock();
 124         for (h = 0; h < 2; h++) {
 125                 _ao_flash_half_page(page, src);
 126                 page += 32;
 127                 src += 32;
 128         }
 129         ao_flash_lock();
 130         ao_arch_release_interrupts();
 131 }