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

Purna Chandra Mandal purna.mandal at microchip.com
Thu Mar 10 14:12:54 CET 2016


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 at 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"
+	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 at microchip.com>
+ * Purna Chandra Mandal <purna.mandal at 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.
+		 */
+		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;
+	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));
+		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
+	 */
+	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.
+	 */
+	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



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