[U-Boot] [PATCH] drivers: mtd: add Microchip PIC32 internal non-CFI flash driver.

[Purna Chandra Mandal <purna.mandal@microchip.com>]

On 03/14/2016 06:13 PM, Daniel Schwierzeck wrote:

> 2016-03-10 14:12 GMT+01:00 Purna Chandra Mandal <purna.mandal@microchip.com>:
>> PIC32 embedded flash banks are memory mapped, directly read by CPU,
>> and programming (erase followed by write) operation on them are
>> handled by on-chip NVM controller.
>>
>> Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
>>
>> ---
>>
>>  drivers/mtd/Kconfig       |   6 +
>>  drivers/mtd/Makefile      |   1 +
>>  drivers/mtd/pic32_flash.c | 377 ++++++++++++++++++++++++++++++++++++++++++++++
>>  include/flash.h           |   5 +-
>>  4 files changed, 388 insertions(+), 1 deletion(-)
>>  create mode 100644 drivers/mtd/pic32_flash.c
>>
>> diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
>> index c58841e..e3c6b9f 100644
>> --- a/drivers/mtd/Kconfig
>> +++ b/drivers/mtd/Kconfig
>> @@ -30,6 +30,12 @@ config ALTERA_QSPI
>>
>>  endmenu
>>
>> +config FLASH_PIC32
>> +       bool "Microchip PIC32 Flash driver"
> you should add: depends on MACH_PIC32

ack. Will add,

>> +       help
>> +         This enables access to Microchip PIC32 internal non-CFI flash
>> +         chips through PIC32 Non-Volatile-Memory Controller.
>> +
>>  source "drivers/mtd/nand/Kconfig"
>>
>>  source "drivers/mtd/spi/Kconfig"
>> diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
>> index 7f018a4..9380085 100644
>> --- a/drivers/mtd/Makefile
>> +++ b/drivers/mtd/Makefile
>> @@ -19,4 +19,5 @@ obj-$(CONFIG_HAS_DATAFLASH) += dataflash.o
>>  obj-$(CONFIG_FTSMC020) += ftsmc020.o
>>  obj-$(CONFIG_FLASH_CFI_LEGACY) += jedec_flash.o
>>  obj-$(CONFIG_MW_EEPROM) += mw_eeprom.o
>> +obj-$(CONFIG_FLASH_PIC32) += pic32_flash.o
>>  obj-$(CONFIG_ST_SMI) += st_smi.o
>> diff --git a/drivers/mtd/pic32_flash.c b/drivers/mtd/pic32_flash.c
>> new file mode 100644
>> index 0000000..9a226b1
>> --- /dev/null
>> +++ b/drivers/mtd/pic32_flash.c
>> @@ -0,0 +1,377 @@
>> +/*
>> + * Copyright (C) 2015
>> + * Cristian Birsan <cristian.birsan@microchip.com>
>> + * Purna Chandra Mandal <purna.mandal@microchip.com>
>> + *
>> + * SPDX-License-Identifier:    GPL-2.0+
>> + */
>> +
>> +#include <common.h>
>> +#include <flash.h>
>> +#include <mach/pic32.h>
>> +#include <wait_bit.h>
>> +
>> +/* NVM Controller registers */
>> +struct pic32_reg_nvm {
>> +       struct pic32_reg_atomic ctrl;
>> +       struct pic32_reg_atomic key;
>> +       struct pic32_reg_atomic addr;
>> +       struct pic32_reg_atomic data;
>> +};
>> +
>> +/* NVM operations */
>> +#define NVMOP_NOP              0
>> +#define NVMOP_WORD_WRITE       1
>> +#define NVMOP_PAGE_ERASE       4
>> +
>> +/* NVM control bits */
>> +#define NVM_WR                 BIT(15)
>> +#define NVM_WREN               BIT(14)
>> +#define NVM_WRERR              BIT(13)
>> +#define NVM_LVDERR             BIT(12)
>> +
>> +/* NVM programming unlock register */
>> +#define LOCK_KEY               0x0
>> +#define UNLOCK_KEY1            0xaa996655
>> +#define UNLOCK_KEY2            0x556699aa
>> +
>> +/* PIC32 flash banks consist of number of pages, each page
>> + * into number of row and rows are into number of words.
>> + * Here we will maintain page information instead of sector.
>> + */
>> +flash_info_t flash_info[CONFIG_SYS_MAX_FLASH_BANKS];
>> +static struct pic32_reg_nvm *nvm_regs_p;
>> +
>> +static inline void flash_initiate_operation(u32 nvmop)
>> +{
>> +       /* set operation */
>> +       writel(nvmop, &nvm_regs_p->ctrl.raw);
>> +
>> +       /* enable flash write */
>> +       writel(NVM_WREN, &nvm_regs_p->ctrl.set);
>> +
>> +       /* unlock sequence */
>> +       writel(LOCK_KEY, &nvm_regs_p->key.raw);
>> +       writel(UNLOCK_KEY1, &nvm_regs_p->key.raw);
>> +       writel(UNLOCK_KEY2, &nvm_regs_p->key.raw);
>> +
>> +       /* initiate operation */
>> +       writel(NVM_WR, &nvm_regs_p->ctrl.set);
>> +}
>> +
>> +static int flash_wait_till_busy(const char *func, ulong timeout)
>> +{
>> +       int ret = wait_for_bit(__func__, &nvm_regs_p->ctrl.raw,
>> +                              NVM_WR, false, timeout, false);
>> +
>> +       return ret ? ERR_TIMOUT : ERR_OK;
>> +}
>> +
>> +static inline int flash_complete_operation(void)
>> +{
>> +       u32 v;
>> +
>> +       v = readl(&nvm_regs_p->ctrl.raw);
>> +       if (v & NVM_WRERR) {
>> +               printf("Error in Block Erase - Lock Bit may be set!\n");
>> +               flash_initiate_operation(NVMOP_NOP);
>> +               return ERR_PROTECTED;
>> +       }
>> +
>> +       if (v & NVM_LVDERR) {
>> +               printf("Error in Block Erase - low-vol detected!\n");
>> +               flash_initiate_operation(NVMOP_NOP);
>> +               return ERR_NOT_ERASED;
>> +       }
>> +
>> +       /* disable flash write or erase operation */
>> +       writel(NVM_WREN, &nvm_regs_p->ctrl.clr);
>> +
>> +       return ERR_OK;
>> +}
>> +
>> +int flash_erase(flash_info_t *info, int s_first, int s_last)
>> +{
>> +       ulong sect_start, sect_end, flags;
>> +       int prot, sect;
>> +       int rc;
>> +
>> +       if ((info->flash_id & FLASH_VENDMASK) != FLASH_MAN_MCHP) {
>> +               printf("Can't erase unknown flash type %08lx - aborted\n",
>> +                      info->flash_id);
>> +               return ERR_UNKNOWN_FLASH_VENDOR;
>> +       }
>> +
>> +       if ((s_first < 0) || (s_first > s_last)) {
>> +               printf("- no sectors to erase\n");
>> +               return ERR_INVAL;
>> +       }
>> +
>> +       prot = 0;
>> +       for (sect = s_first; sect <= s_last; ++sect) {
>> +               if (info->protect[sect])
>> +                       prot++;
>> +       }
>> +
>> +       if (prot)
>> +               printf("- Warning: %d protected sectors will not be erased!\n",
>> +                      prot);
>> +       else
>> +               printf("\n");
>> +
>> +       /* erase on unprotected sectors */
>> +       for (sect = s_first; sect <= s_last; sect++) {
>> +               if (info->protect[sect])
>> +                       continue;
>> +
>> +               /* disable interrupts */
>> +               flags = disable_interrupts();
>> +
>> +               /* write destination page address (physical) */
>> +               sect_start = virt_to_phys((void *)info->start[sect]);
>> +               writel(sect_start, &nvm_regs_p->addr.raw);
>> +
>> +               /* page erase */
>> +               flash_initiate_operation(NVMOP_PAGE_ERASE);
>> +
>> +               /* wait */
>> +               rc = flash_wait_till_busy(__func__,
>> +                                         CONFIG_SYS_FLASH_ERASE_TOUT);
>> +
>> +               /* re-enable interrupts if necessary */
>> +               if (flags)
>> +                       enable_interrupts();
>> +
>> +               if (rc != ERR_OK)
>> +                       return rc;
>> +
>> +               rc = flash_complete_operation();
>> +               if (rc != ERR_OK)
>> +                       return rc;
>> +
>> +               /* flash content is updated but cache might contain stale
>> +                * data, so invalidate dcache.
>> +                */
> incorrect multi-line comment

ack.

>> +               sect_end = info->start[sect] + info->size / info->sector_count;
>> +               invalidate_dcache_range(info->start[sect], sect_end);
>> +       }
>> +
>> +       printf(" done\n");
>> +       return ERR_OK;
>> +}
>> +
>> +int page_erase(flash_info_t *info, int sect)
>> +{
>> +       return 0;
>> +}
>> +
>> +/* Write a word to flash */
>> +static int write_word(flash_info_t *info, ulong dest, ulong data)
>> +{
>> +       vu_long *addr = (vu_long *)dest;
> you don't need a volatile pointer. Also virt_to_phys() is not meant to
> be used in a driver. An alternative is:
>
> void *addr = (void *)CPHYSADDR(dest);

ack.

>> +       ulong flags;
>> +       int rc;
>> +
>> +       /* check if flash is (sufficiently) erased */
>> +       if ((*addr & data) != data) {
>> +               printf("Error, Flash not erased!\n");
>> +               return ERR_NOT_ERASED;
>> +       }
>> +
>> +       /* disable interrupts */
>> +       flags = disable_interrupts();
>> +
>> +       /* update destination page address (physical) */
>> +       writel(virt_to_phys(addr), &nvm_regs_p->addr.raw);
>> +       writel(data, &nvm_regs_p->data.raw);
>> +
>> +       /* word write */
>> +       flash_initiate_operation(NVMOP_WORD_WRITE);
>> +
>> +       /* wait for operation to complete */
>> +       rc = flash_wait_till_busy(__func__, CONFIG_SYS_FLASH_WRITE_TOUT);
>> +
>> +       /* re-enable interrupts if necessary */
>> +       if (flags)
>> +               enable_interrupts();
>> +
>> +       if (rc != ERR_OK)
>> +               return rc;
>> +
>> +       return flash_complete_operation();
>> +}
>> +
>> +/* Copy memory to flash, returns:
>> + * ERR_OK - OK
>> + * ERR_TIMOUT - write timeout
>> + * ERR_NOT_ERASED - Flash not erased
>> + */
>> +int write_buff(flash_info_t *info, uchar *src, ulong addr, ulong cnt)
>> +{
>> +       ulong wp, data, len = cnt;
>> +       int i, l, rc;
>> +       uchar *cp;
>> +
>> +       wp = (addr & ~3);       /* get lower word aligned address */
>> +
>> +       /*
>> +        * handle unaligned start bytes
>> +        */
>> +       l = addr - wp;
>> +       if (l != 0) {
>> +               data = 0;
>> +               for (i = 0, cp = (uchar *)wp; i < l; ++i, ++cp)
>> +                       data = (data << 8) | *cp;
>> +
>> +               for (; (i < 4) && (cnt > 0); ++i) {
>> +                       data = (data << 8) | *src++;
>> +                       --cnt;
>> +                       ++cp;
>> +               }
>> +
>> +               for (; (cnt == 0) && (i < 4); ++i, ++cp)
>> +                       data = (data << 8) | *cp;
>> +
>> +               rc = write_word(info, wp, __swab32(data));
> why do you need to swap the data? Is the endianess of the flash
> controller or chip different from the one of the CPU? If so, you
> should explicitely state this with cpu_to_be32() or cpu_to_le32().
> Also shouldn't the swapping be done in write_word()?

Good catch. Please note, both MIPS and flash controller is little-endian.

If you see, though not very obvious, char-byte-stream to word-data
formatting is generating big-endian word. So to revert that __swab is
used. Will fix the conversion so that generated word-data is
little-endian itself at first hand.

>> +               if (rc)
>> +                       goto out;
>> +
>> +               wp += 4;
>> +       }
>> +
>> +       /*
>> +        * handle word aligned part
>> +        */
>> +       while (cnt >= 4) {
>> +               data = 0;
>> +               for (i = 0; i < 4; ++i)
>> +                       data = (data << 8) | *src++;
>> +
>> +               rc = write_word(info, wp, __swab32(data));
>> +               if (rc)
>> +                       goto out;
>> +
>> +               wp  += 4;
>> +               cnt -= 4;
>> +       }
>> +
>> +       if (cnt == 0) {
>> +               rc = ERR_OK;
>> +               goto out;
>> +       }
>> +
>> +       /*
>> +        * handle unaligned tail bytes
>> +        */
> should be a single-line comment

ack.

>> +       data = 0;
>> +       for (i = 0, cp = (uchar *)wp; (i < 4) && (cnt > 0); ++i, ++cp) {
>> +               data = (data << 8) | *src++;
>> +               --cnt;
>> +       }
>> +
>> +       for (; i < 4; ++i, ++cp)
>> +               data = (data << 8) | *cp;
>> +
>> +       rc = write_word(info, wp,  __swab32(data));
>> +
>> +out:
>> +       /* flash content updated by nvm controller,
>> +        * but cache might have stale, so invalidate dcache.
>> +        */
> incorrect multi-line comment

ack.

>> +       invalidate_dcache_range(addr, addr + len);
>> +
>> +       printf(" done\n");
>> +       return rc;
>> +}
>> +
>> +void flash_print_info(flash_info_t *info)
>> +{
>> +       int i;
>> +
>> +       if (info->flash_id == FLASH_UNKNOWN) {
>> +               printf("missing or unknown FLASH type\n");
>> +               return;
>> +       }
>> +
>> +       switch (info->flash_id & FLASH_VENDMASK) {
>> +       case FLASH_MAN_MCHP:
>> +               printf("Microchip Technology");
>> +               break;
>> +       default:
>> +               printf("Unknown Vendor ");
>> +               break;
>> +       }
>> +
>> +       switch (info->flash_id & FLASH_TYPEMASK) {
>> +       case FLASH_MCHP100T:
>> +               printf("Internal (8 Mbit, 64 x 16k)\n");
>> +               break;
>> +       default:
>> +               printf("Unknown Chip Type\n");
>> +               break;
>> +       }
>> +
>> +       printf("  Size: %ld MB in %d Sectors\n",
>> +              info->size >> 20, info->sector_count);
>> +
>> +       printf("  Sector Start Addresses:");
>> +       for (i = 0; i < info->sector_count; ++i) {
>> +               if ((i % 5) == 0)
>> +                       printf("\n   ");
>> +
>> +               printf(" %08lX%s", info->start[i],
>> +                      info->protect[i] ? " (RO)" : "     ");
>> +       }
>> +       printf("\n");
>> +}
>> +
>> +unsigned long flash_init(void)
>> +{
>> +       phys_addr_t flash_banks[] = CONFIG_SYS_FLASH_BANKS_LIST;
>> +       flash_info_t *info = &flash_info[0];
>> +       ulong total_size = 0;
>> +       ulong sect_size;
>> +       ulong base;
>> +       int bank, sect;
>> +
>> +       sect_size = CONFIG_SYS_FLASH_SIZE / CONFIG_SYS_MAX_FLASH_SECT;
>> +       for (bank = 0; bank < CONFIG_SYS_MAX_FLASH_BANKS; ++bank, ++info) {
>> +               /* combined device & manufacturer code */
>> +               info->flash_id = FLASH_MAN_MCHP | FLASH_MCHP100T;
>> +               info->sector_count = CONFIG_SYS_MAX_FLASH_SECT;
>> +               info->size = CONFIG_SYS_FLASH_SIZE;
>> +
>> +               /* update sector (i.e page) info */
>> +               base = (ulong)phys_to_virt(flash_banks[bank]);
>> +               for (sect = 0; sect < info->sector_count; sect++) {
>> +                       info->start[sect] = base;
>> +                       /* protect each sector by default */
>> +                       info->protect[sect] = 1;
>> +                       base += sect_size;
>> +               }
>> +               total_size += info->size;
>> +       }
>> +
>> +       /* NVM controller iobase */
>> +       nvm_regs_p = ioremap(PIC32_NVM_BASE, sizeof(*nvm_regs_p));
>> +
>> +       /* disable flash write/erase operations */
>> +       writel(NVM_WREN, &nvm_regs_p->ctrl.clr);
>> +
>> +#if (CONFIG_SYS_MONITOR_BASE >= CONFIG_SYS_FLASH_BASE)
>> +       /* monitor protection ON by default */
>> +       flash_protect(FLAG_PROTECT_SET,
>> +                     CONFIG_SYS_MONITOR_BASE,
>> +                     CONFIG_SYS_MONITOR_BASE + monitor_flash_len - 1,
>> +                     &flash_info[0]);
>> +#endif
>> +
>> +#ifdef CONFIG_ENV_IS_IN_FLASH
>> +       /* ENV protection ON by default */
>> +       flash_protect(FLAG_PROTECT_SET,
>> +                     CONFIG_ENV_ADDR,
>> +                     CONFIG_ENV_ADDR + CONFIG_ENV_SECT_SIZE - 1,
>> +                     &flash_info[0]);
>> +#endif
>> +       return total_size;
>> +}
>> diff --git a/include/flash.h b/include/flash.h
>> index f53ace7..c9aacd5 100644
>> --- a/include/flash.h
>> +++ b/include/flash.h
>> @@ -400,6 +400,9 @@ extern flash_info_t *flash_get_info(ulong base);
>>  #define FLASH_STM800DT 0x00D7          /* STM M29W800DT (1M = 64K x 16, top)   */
>>  #define FLASH_STM800DB 0x005B          /* STM M29W800DB (1M = 64K x 16, bottom)*/
>>
>> +#define FLASH_MCHP100T 0x0060          /* MCHP internal (1M = 64K x 16) */
>> +#define FLASH_MCHP100B 0x0061          /* MCHP internal (1M = 64K x 16) */
>> +
>>  #define FLASH_28F400_T 0x0062          /* MT  28F400B3 ID (  4M = 256K x 16 )  */
>>  #define FLASH_28F400_B 0x0063          /* MT  28F400B3 ID (  4M = 256K x 16 )  */
>>
>> @@ -486,7 +489,7 @@ extern flash_info_t *flash_get_info(ulong base);
>>  #define FLASH_MAN_SHARP 0x00500000
>>  #define FLASH_MAN_ATM  0x00600000
>>  #define FLASH_MAN_CFI  0x01000000
>> -
>> +#define FLASH_MAN_MCHP 0x02000000      /* Microchip Technology         */
>>
>>  #define FLASH_TYPEMASK 0x0000FFFF      /* extract FLASH type   information     */
>>  #define FLASH_VENDMASK 0xFFFF0000      /* extract FLASH vendor information     */
>> --
>> 1.8.3.1
>>
> adding new flash ID's should be done in a separate patch

ack. Will separate.