From: Reinhard Meyer <i...@emk-elektronik.de>

Signed-off-by: Reinhard Meyer <u-b...@emk-elektronik.de>
---
 drivers/mtd/spi/Makefile             |    1 +
 drivers/mtd/spi/ramtron.c            |  297 ++++++++++++++++++++++++++++++++++
 drivers/mtd/spi/spi_flash.c          |   13 ++
 drivers/mtd/spi/spi_flash_internal.h |    2 +
 4 files changed, 313 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mtd/spi/ramtron.c

diff --git a/drivers/mtd/spi/Makefile b/drivers/mtd/spi/Makefile
index 4f11b36..a082ca7 100644
--- a/drivers/mtd/spi/Makefile
+++ b/drivers/mtd/spi/Makefile
@@ -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
index 0000000..9271e5b
--- /dev/null
+++ b/drivers/mtd/spi/ramtron.c
@@ -0,0 +1,297 @@
+/*
+ * (C) Copyright 2010
+ * Reinhard Meyer, EMK Elektronik, reinhard.me...@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 FRAMs do not have a means of
+ * identifying them. We use an environment variable to select
+ * the device we will handle. The variable "fram_device" should
+ * be set from VPD data.
+ */
+
+#define        DEBUG 1 /* remove this once its been thoroughly tested */
+
+#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 */
+
+#define        ENV_VARIABLE            "fram_device"
+
+/*
+ * 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[] = {
+       /* FM25V02: */
+       {.size = 32*1024, .addr_len = 2, .merge_cmd = 0,
+               .id1 = 0x22, .id2 = 0x00, .speed = 40000000, .name = "FM25V02", 
},
+       /* FM25VN02: */
+       {.size = 32*1024, .addr_len = 2, .merge_cmd = 0,
+               .id1 = 0x22, .id2 = 0x01, .speed = 40000000, .name = 
"FM25VN02", },
+       /* FM25V05: */
+       { .size = 64*1024, .addr_len = 2, .merge_cmd = 0,
+               .id1 = 0x23, .id2 = 0x00, .speed = 40000000, .name = "FM25V05", 
},
+       /* FM25VN05: */
+       {.size = 64*1024, .addr_len = 2, .merge_cmd = 0,
+               .id1 = 0x23, .id2 = 0x01, .speed = 40000000, .name = 
"FM25VN05", },
+       /* FM25V10: */
+       {.size = 128*1024, .addr_len = 3, .merge_cmd = 0,
+               .id1 = 0x24, .id2 = 0x00, .speed = 40000000, .name = "FM25V10", 
},
+       /* FM25VN10: */
+       {.size = 128*1024, .addr_len = 3, .merge_cmd = 0,
+               .id1 = 0x24, .id2 = 0x01, .speed = 40000000, .name = 
"FM25VN10", },
+       /* FM25H20: no identification */
+       {.size = 256*1024, .addr_len = 3, .merge_cmd = 0,
+               .id1 = 0xff, .id2 = 0xff, .speed = 40000000, .name = "FM25H20", 
},
+};
+
+static int ramtron_read(struct spi_flash *flash,
+                            u32 offset, size_t len, void *buf)
+{
+       struct ramtron_spi_fram *sn = to_ramtron_spi_fram(flash);
+       u8 cmd[4];
+       u8 cmd_len = 1;
+       int ret;
+
+       if (sn->params->addr_len == 3 && sn->params->merge_cmd == 0) {
+               cmd[0] = CMD_RAMTRON_READ;
+               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] = CMD_RAMTRON_READ;
+               cmd[1] = offset >> 8;
+               cmd[2] = offset;
+               cmd_len = 3;
+       }
+       else {
+               printf("SF: unsupported addr_len or merge_cmd\n");
+               return -1;
+       }
+
+       debug("READ: 0x%x => cmd = { 0x%02x 0x%02x%02x%02x } len = 0x%x\n",
+                offset, cmd[0], cmd[1], cmd[2], cmd[3], len);
+
+       /* claim the bus */
+       ret = spi_claim_bus(flash->spi);
+       if (ret) {
+               debug("SF: Unable to claim SPI bus\n");
+               return ret;
+       }
+
+       /* read the data */
+       ret = spi_flash_read_common(flash, cmd, cmd_len, buf, len);
+       if (ret < 0)
+               debug("SF: Read failed\n");
+
+       /* release the bus */
+       spi_release_bus(flash->spi);
+       return ret;
+}
+
+static int ramtron_write(struct spi_flash *flash,
+                        u32 offset, size_t len, const void *buf)
+{
+       struct ramtron_spi_fram *sn = to_ramtron_spi_fram(flash);
+       u8 cmd[4];
+       u8 cmd_len = 1;
+       int ret;
+
+       if (sn->params->addr_len == 3 && sn->params->merge_cmd == 0) {
+               cmd[0] = CMD_RAMTRON_WRITE;
+               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] = CMD_RAMTRON_WRITE;
+               cmd[1] = offset >> 8;
+               cmd[2] = offset;
+               cmd_len = 3;
+       }
+       else {
+               printf("SF: unsupported addr_len or merge_cmd\n");
+               return -1;
+       }
+
+       debug("WRITE: 0x%x => cmd = { 0x%02x 0x%02x%02x%02x } len = 0x%x\n",
+                offset, cmd[0], cmd[1], cmd[2], cmd[3], len);
+
+       /* claim the bus */
+       ret = spi_claim_bus(flash->spi);
+       if (ret) {
+               debug("SF: Unable to claim SPI bus\n");
+               return ret;
+       }
+
+       /* send WREN */
+       ret = spi_flash_cmd(flash->spi, CMD_RAMTRON_WREN, NULL, 0);
+       if (ret < 0) {
+               debug("SF: Enabling Write failed\n");
+               goto releasebus;
+       }
+
+       /* write the data */
+       ret = spi_flash_cmd_write(flash->spi, cmd, cmd_len, buf, len);
+       if (ret < 0)
+               debug("SF: Write failed\n");
+
+releasebus:
+       /* release the bus */
+       spi_release_bus(flash->spi);
+       return ret;
+}
+
+int ramtron_erase(struct spi_flash *flash, u32 offset, size_t len)
+{
+       debug("SF: Erase of RAMTRON FRAMs is pointless\n");
+       return -1;
+}
+
+struct spi_flash *spi_fram_probe_ramtron(struct spi_slave *spi)
+{
+       const struct ramtron_spi_fram_params *params;
+       struct ramtron_spi_fram *sn;
+       unsigned int i;
+       u8 idcode[10];
+       int ret;
+       const char *device_name = getenv (ENV_VARIABLE);
+
+       /* NOTE: the bus has been claimed before this function is called! */
+
+       /* try to get an ID first */
+       ret = spi_flash_cmd(spi, CMD_RAMTRON_RDID, &idcode, sizeof(idcode));
+       if (ret) {
+               debug("SF: Read ID command failed\n");
+               return NULL;
+       }
+
+       debug("SF: Got idcode %02x %02x %02x %02x %02x %02x %02x %02x %02x 
%02x\n",
+               idcode[0], idcode[1], idcode[2], idcode[3], idcode[4],
+               idcode[5], idcode[6], idcode[7], idcode[8], idcode[9]);
+
+       /*
+        * RAMTRON chips without RDID command support will keep their Q output
+        * tristated. Depending on MISO termination we will read noise.
+        * Chips with RDID command support will answer 6*0x7f, 0xc2, id1, id2.
+        */
+       if (idcode[0]==0x7f && idcode[1]==0x7f && idcode[2]==0x7f && 
idcode[3]==0x7f &&
+                       idcode[4]==0x7f && idcode[5]==0x7f && idcode[6]==0xc2) {
+               for (i = 0; i < ARRAY_SIZE(ramtron_spi_fram_table); i++) {
+                       params = &ramtron_spi_fram_table[i];
+                       if (idcode[7]==params->id1 && idcode[8]==params->id2)
+                               goto found;
+               }
+               debug("SF: Unsupported RAMTRON device id1=%02x id2=%02x\n",
+                       idcode[7], idcode[8]);
+               return NULL;
+       }
+
+       /*
+        * If no ID was found, we will try the environment variable,
+        * but we will only match chips that do not support RDID command
+        */
+       if (device_name) {
+               for (i = 0; i < ARRAY_SIZE(ramtron_spi_fram_table); i++) {
+                       params = &ramtron_spi_fram_table[i];
+                       if (params->id1==0xff && params->id2==0xff &&
+                                       !strcmp(params->name, device_name))
+                               goto found;
+               }
+               debug("SF: Unsupported RAMTRON device %s\n", device_name);
+               return NULL;
+       }
+
+       /* no success with either method... */
+       return NULL;
+
+found:
+       sn = malloc(sizeof(struct ramtron_spi_fram));
+       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;
+}
+
diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index ea875dc..328366b 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -116,6 +116,19 @@ struct spi_flash *spi_flash_probe(unsigned int bus, 
unsigned int cs,
                goto err_claim_bus;
        }
 
+#ifdef CONFIG_SPI_FRAM_RAMTRON
+       /*
+        * not all RAMTRON FRAMs do have a READ_ID command,
+        * let the ramtron code figure out details
+        */
+       flash = spi_fram_probe_ramtron(spi);
+       if (flash) {
+               spi_release_bus(spi);
+               return flash;
+       }
+       /* if spi_fram_probe did not find anything, continue normal probe */
+#endif
+
        /* Read the ID codes */
        ret = spi_flash_cmd(spi, CMD_READ_ID, &idcode, sizeof(idcode));
        if (ret)
diff --git a/drivers/mtd/spi/spi_flash_internal.h 
b/drivers/mtd/spi/spi_flash_internal.h
index 08546fb..0f1b8da 100644
--- a/drivers/mtd/spi/spi_flash_internal.h
+++ b/drivers/mtd/spi/spi_flash_internal.h
@@ -50,3 +50,5 @@ 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);
+
-- 
1.5.6.5

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