sf: ramtron: new spi fram driver
authorReinhard Meyer <u-boot@emk-elektronik.de>
Tue, 5 Oct 2010 14:56:40 +0000 (16:56 +0200)
committerMike Frysinger <vapier@gentoo.org>
Wed, 10 Nov 2010 09:26:18 +0000 (04:26 -0500)
Supports most types that support Read-Id and the FM25H20.

Signed-off-by: Reinhard Meyer <u-boot@emk-elektronik.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
drivers/mtd/spi/Makefile
drivers/mtd/spi/ramtron.c [new file with mode: 0644]
drivers/mtd/spi/spi_flash.c
drivers/mtd/spi/spi_flash_internal.h

index 4f11b363137a4b0a4dffb68cba0de1124d258276..a082ca7d53a37d4a5f2433e88984a073a5abdcc7 100644 (file)
@@ -32,6 +32,7 @@ COBJS-$(CONFIG_SPI_FLASH_SPANSION)    += spansion.o
 COBJS-$(CONFIG_SPI_FLASH_SST)  += sst.o
 COBJS-$(CONFIG_SPI_FLASH_STMICRO)      += stmicro.o
 COBJS-$(CONFIG_SPI_FLASH_WINBOND)      += winbond.o
+COBJS-$(CONFIG_SPI_FRAM_RAMTRON)       += ramtron.o
 COBJS-$(CONFIG_SPI_M95XXX) += eeprom_m95xxx.o
 
 COBJS  := $(COBJS-y)
diff --git a/drivers/mtd/spi/ramtron.c b/drivers/mtd/spi/ramtron.c
new file mode 100644 (file)
index 0000000..171390d
--- /dev/null
@@ -0,0 +1,319 @@
+/*
+ * (C) Copyright 2010
+ * Reinhard Meyer, EMK Elektronik, reinhard.meyer@emk-elektronik.de
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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
+ */
+
+/*
+ * Note: RAMTRON SPI FRAMs are ferroelectric, nonvolatile RAMs
+ * with an interface identical to SPI flash devices.
+ * However since they behave like RAM there are no delays or
+ * busy polls required. They can sustain read or write at the
+ * allowed SPI bus speed, which can be 40 MHz for some devices.
+ *
+ * Unfortunately some RAMTRON devices do not have a means of
+ * identifying them. They will leave the SO line undriven when
+ * the READ-ID command is issued. It is therefore mandatory
+ * that the MISO line has a proper pull-up, so that READ-ID
+ * will return a row of 0xff. This 0xff pseudo-id will cause
+ * probes by all vendor specific functions that are designed
+ * to handle it. If the MISO line is not pulled up, READ-ID
+ * could return any random noise, even mimicking another
+ * device.
+ *
+ * We use CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC
+ * to define which device will be assumed after a simple status
+ * register verify. This method is prone to false positive
+ * detection and should therefore be the last to be tried.
+ * Enter it in the last position in the table in spi_flash.c!
+ *
+ * The define CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC both activates
+ * compilation of the special handler and defines the device
+ * to assume.
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi_flash.h>
+#include "spi_flash_internal.h"
+
+/* RAMTRON commands common to all devices */
+#define CMD_RAMTRON_WREN       0x06    /* Write Enable */
+#define CMD_RAMTRON_WRDI       0x04    /* Write Disable */
+#define CMD_RAMTRON_RDSR       0x05    /* Read Status Register */
+#define CMD_RAMTRON_WRSR       0x01    /* Write Status Register */
+#define CMD_RAMTRON_READ       0x03    /* Read Data Bytes */
+#define CMD_RAMTRON_WRITE      0x02    /* Write Data Bytes */
+/* not all have those: */
+#define CMD_RAMTRON_FSTRD      0x0b    /* Fast Read (for compatibility - not used here) */
+#define CMD_RAMTRON_SLEEP      0xb9    /* Enter Sleep Mode */
+#define CMD_RAMTRON_RDID       0x9f    /* Read ID */
+#define CMD_RAMTRON_SNR                0xc3    /* Read Serial Number */
+
+/*
+ * Properties of supported FRAMs
+ * Note: speed is currently not used because we have no method to deliver that
+ * value to the upper layers
+ */
+struct ramtron_spi_fram_params {
+       u32     size;           /* size in bytes */
+       u8      addr_len;       /* number of address bytes */
+       u8      merge_cmd;      /* some address bits are in the command byte */
+       u8      id1;            /* device ID 1 (family, density) */
+       u8      id2;            /* device ID 2 (sub, rev, rsvd) */
+       u32     speed;          /* max. SPI clock in Hz */
+       const char *name;       /* name for display and/or matching */
+};
+
+struct ramtron_spi_fram {
+       struct spi_flash flash;
+       const struct ramtron_spi_fram_params *params;
+};
+
+static inline struct ramtron_spi_fram *to_ramtron_spi_fram(struct spi_flash
+                                                            *flash)
+{
+       return container_of(flash, struct ramtron_spi_fram, flash);
+}
+
+/*
+ * table describing supported FRAM chips:
+ * chips without RDID command must have the values 0xff for id1 and id2
+ */
+static const struct ramtron_spi_fram_params ramtron_spi_fram_table[] = {
+       {
+               .size = 32*1024,
+               .addr_len = 2,
+               .merge_cmd = 0,
+               .id1 = 0x22,
+               .id2 = 0x00,
+               .speed = 40000000,
+               .name = "FM25V02",
+       },
+       {
+               .size = 32*1024,
+               .addr_len = 2,
+               .merge_cmd = 0,
+               .id1 = 0x22,
+               .id2 = 0x01,
+               .speed = 40000000,
+               .name = "FM25VN02",
+       },
+       {
+               .size = 64*1024,
+               .addr_len = 2,
+               .merge_cmd = 0,
+               .id1 = 0x23,
+               .id2 = 0x00,
+               .speed = 40000000,
+               .name = "FM25V05",
+       },
+       {
+               .size = 64*1024,
+               .addr_len = 2,
+               .merge_cmd = 0,
+               .id1 = 0x23,
+               .id2 = 0x01,
+               .speed = 40000000,
+               .name = "FM25VN05",
+       },
+       {
+               .size = 128*1024,
+               .addr_len = 3,
+               .merge_cmd = 0,
+               .id1 = 0x24,
+               .id2 = 0x00,
+               .speed = 40000000,
+               .name = "FM25V10",
+       },
+       {
+               .size = 128*1024,
+               .addr_len = 3,
+               .merge_cmd = 0,
+               .id1 = 0x24,
+               .id2 = 0x01,
+               .speed = 40000000,
+               .name = "FM25VN10",
+       },
+#ifdef CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC
+       {
+               .size = 256*1024,
+               .addr_len = 3,
+               .merge_cmd = 0,
+               .id1 = 0xff,
+               .id2 = 0xff,
+               .speed = 40000000,
+               .name = "FM25H20",
+       },
+#endif
+};
+
+static int ramtron_common(struct spi_flash *flash,
+               u32 offset, size_t len, void *buf, u8 command)
+{
+       struct ramtron_spi_fram *sn = to_ramtron_spi_fram(flash);
+       u8 cmd[4];
+       int cmd_len;
+       int ret;
+
+       if (sn->params->addr_len == 3 && sn->params->merge_cmd == 0) {
+               cmd[0] = command;
+               cmd[1] = offset >> 16;
+               cmd[2] = offset >> 8;
+               cmd[3] = offset;
+               cmd_len = 4;
+       } else if (sn->params->addr_len == 2 && sn->params->merge_cmd == 0) {
+               cmd[0] = command;
+               cmd[1] = offset >> 8;
+               cmd[2] = offset;
+               cmd_len = 3;
+       } else {
+               printf("SF: unsupported addr_len or merge_cmd\n");
+               return -1;
+       }
+
+       /* claim the bus */
+       ret = spi_claim_bus(flash->spi);
+       if (ret) {
+               debug("SF: Unable to claim SPI bus\n");
+               return ret;
+       }
+
+       if (command == CMD_RAMTRON_WRITE) {
+               /* send WREN */
+               ret = spi_flash_cmd(flash->spi, CMD_RAMTRON_WREN, NULL, 0);
+               if (ret < 0) {
+                       debug("SF: Enabling Write failed\n");
+                       goto releasebus;
+               }
+       }
+
+       /* do the transaction */
+       if (command == CMD_RAMTRON_WRITE)
+               ret = spi_flash_cmd_write(flash->spi, cmd, cmd_len, buf, len);
+       else
+               ret = spi_flash_cmd_read(flash->spi, cmd, cmd_len, buf, len);
+       if (ret < 0)
+               debug("SF: Transaction failed\n");
+
+releasebus:
+       /* release the bus */
+       spi_release_bus(flash->spi);
+       return ret;
+}
+
+static int ramtron_read(struct spi_flash *flash,
+               u32 offset, size_t len, void *buf)
+{
+       return ramtron_common(flash, offset, len, buf,
+               CMD_RAMTRON_READ);
+}
+
+static int ramtron_write(struct spi_flash *flash,
+               u32 offset, size_t len, const void *buf)
+{
+       return ramtron_common(flash, offset, len, (void *)buf,
+               CMD_RAMTRON_WRITE);
+}
+
+int ramtron_erase(struct spi_flash *flash, u32 offset, size_t len)
+{
+       debug("SF: Erase of RAMTRON FRAMs is pointless\n");
+       return -1;
+}
+
+/*
+ * nore: we are called here with idcode pointing to the first non-0x7f byte
+ * already!
+ */
+struct spi_flash *spi_fram_probe_ramtron(struct spi_slave *spi, u8 *idcode)
+{
+       const struct ramtron_spi_fram_params *params;
+       struct ramtron_spi_fram *sn;
+       unsigned int i;
+#ifdef CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC
+       int ret;
+       u8 sr;
+#endif
+
+       /* NOTE: the bus has been claimed before this function is called! */
+       switch (idcode[0]) {
+       case 0xc2:
+               /* JEDEC conformant RAMTRON id */
+               for (i = 0; i < ARRAY_SIZE(ramtron_spi_fram_table); i++) {
+                       params = &ramtron_spi_fram_table[i];
+                       if (idcode[1] == params->id1 && idcode[2] == params->id2)
+                               goto found;
+               }
+               break;
+#ifdef CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC
+       case 0xff:
+               /*
+                * probably open MISO line, pulled up.
+                * We COULD have a non JEDEC conformant FRAM here,
+                * read the status register to verify
+                */
+               ret = spi_flash_cmd(spi, CMD_RAMTRON_RDSR, &sr, 1);
+               if (ret)
+                       return NULL;
+
+               /* Bits 5,4,0 are fixed 0 for all devices */
+               if ((sr & 0x31) != 0x00)
+                       return NULL;
+               /* now find the device */
+               for (i = 0; i < ARRAY_SIZE(ramtron_spi_fram_table); i++) {
+                       params = &ramtron_spi_fram_table[i];
+                       if (!strcmp(params->name, CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC))
+                               goto found;
+               }
+               debug("SF: Unsupported non-JEDEC RAMTRON device "
+                       CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC "\n");
+               break;
+#endif
+       default:
+               break;
+       }
+
+       /* arriving here means no method has found a device we can handle */
+       debug("SF/ramtron: unsupported device id0=%02x id1=%02x id2=%02x\n",
+               idcode[0], idcode[1], idcode[2]);
+       return NULL;
+
+found:
+       sn = malloc(sizeof(*sn));
+       if (!sn) {
+               debug("SF: Failed to allocate memory\n");
+               return NULL;
+       }
+
+       sn->params = params;
+       sn->flash.spi = spi;
+       sn->flash.name = params->name;
+
+       sn->flash.write = ramtron_write;
+       sn->flash.read = ramtron_read;
+       sn->flash.erase = ramtron_erase;
+       sn->flash.size = params->size;
+
+       printf("SF: Detected %s with size ", params->name);
+       print_size(sn->flash.size, "\n");
+
+       return &sn->flash;
+}
index b4ba1dda51dc4fee48116841f702d17787e11787..ab02ef3e04db5d09916d2a65aaaefc5aaa37a7d6 100644 (file)
@@ -145,11 +145,19 @@ static const struct {
 #endif
 #ifdef CONFIG_SPI_FLASH_WINBOND
        { 0, 0xef, spi_flash_probe_winbond, },
+#endif
+#ifdef CONFIG_SPI_FRAM_RAMTRON
+       { 6, 0xc2, spi_fram_probe_ramtron, },
+# undef IDCODE_CONT_LEN
+# define IDCODE_CONT_LEN 6
 #endif
        /* Keep it sorted by best detection */
 #ifdef CONFIG_SPI_FLASH_STMICRO
        { 0, 0xff, spi_flash_probe_stmicro, },
 #endif
+#ifdef CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC
+       { 0, 0xff, spi_fram_probe_ramtron, },
+#endif
 };
 #define IDCODE_LEN (IDCODE_CONT_LEN + IDCODE_PART_LEN)
 
index 08546fbb03895a8f1ffd358bb417ea48622482a6..9bc43dd21e17eba88c154f79b464f4b17d81579c 100644 (file)
@@ -50,3 +50,4 @@ struct spi_flash *spi_flash_probe_macronix(struct spi_slave *spi, u8 *idcode);
 struct spi_flash *spi_flash_probe_sst(struct spi_slave *spi, u8 *idcode);
 struct spi_flash *spi_flash_probe_stmicro(struct spi_slave *spi, u8 *idcode);
 struct spi_flash *spi_flash_probe_winbond(struct spi_slave *spi, u8 *idcode);
+struct spi_flash *spi_fram_probe_ramtron(struct spi_slave *spi, u8 *idcode);