--- /dev/null
+/*
+ * (C) Copyright 2010
+ * Reinhard Meyer, EMK Elektronik, reinhard.meyer@emk-elektronik.de
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+/*
+ * 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 "sf_internal.h"
+
+/*
+ * 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_PAGE_PROGRAM) {
+ /* send WREN */
+ ret = spi_flash_cmd_write_enable(flash);
+ if (ret < 0) {
+ debug("SF: Enabling Write failed\n");
+ goto releasebus;
+ }
+ }
+
+ /* do the transaction */
+ if (command == CMD_PAGE_PROGRAM)
+ 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_READ_ARRAY_SLOW);
+}
+
+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_PAGE_PROGRAM);
+}
+
+static 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!
+ */
+static 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_READ_STATUS, &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.write = ramtron_write;
+ sn->flash.read = ramtron_read;
+ sn->flash.erase = ramtron_erase;
+ sn->flash.size = params->size;
+
+ return &sn->flash;
+}
+
+/*
+ * The following table holds all device probe functions
+ * (All flashes are removed and implemented a common probe at
+ * spi_flash_probe.c)
+ *
+ * shift: number of continuation bytes before the ID
+ * idcode: the expected IDCODE or 0xff for non JEDEC devices
+ * probe: the function to call
+ *
+ * Non JEDEC devices should be ordered in the table such that
+ * the probe functions with best detection algorithms come first.
+ *
+ * Several matching entries are permitted, they will be tried
+ * in sequence until a probe function returns non NULL.
+ *
+ * IDCODE_CONT_LEN may be redefined if a device needs to declare a
+ * larger "shift" value. IDCODE_PART_LEN generally shouldn't be
+ * changed. This is the max number of bytes probe functions may
+ * examine when looking up part-specific identification info.
+ *
+ * Probe functions will be given the idcode buffer starting at their
+ * manu id byte (the "idcode" in the table below). In other words,
+ * all of the continuation bytes will be skipped (the "shift" below).
+ */
+#define IDCODE_CONT_LEN 0
+#define IDCODE_PART_LEN 5
+static const struct {
+ const u8 shift;
+ const u8 idcode;
+ struct spi_flash *(*probe) (struct spi_slave *spi, u8 *idcode);
+} flashes[] = {
+ /* Keep it sorted by define name */
+#ifdef CONFIG_SPI_FRAM_RAMTRON
+ { 6, 0xc2, spi_fram_probe_ramtron, },
+# undef IDCODE_CONT_LEN
+# define IDCODE_CONT_LEN 6
+#endif
+#ifdef CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC
+ { 0, 0xff, spi_fram_probe_ramtron, },
+#endif
+};
+#define IDCODE_LEN (IDCODE_CONT_LEN + IDCODE_PART_LEN)
+
+struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int spi_mode)
+{
+ struct spi_slave *spi;
+ struct spi_flash *flash = NULL;
+ int ret, i, shift;
+ u8 idcode[IDCODE_LEN], *idp;
+
+ spi = spi_setup_slave(bus, cs, max_hz, spi_mode);
+ if (!spi) {
+ printf("SF: Failed to set up slave\n");
+ return NULL;
+ }
+
+ ret = spi_claim_bus(spi);
+ if (ret) {
+ debug("SF: Failed to claim SPI bus: %d\n", ret);
+ goto err_claim_bus;
+ }
+
+ /* Read the ID codes */
+ ret = spi_flash_cmd(spi, CMD_READ_ID, idcode, sizeof(idcode));
+ if (ret)
+ goto err_read_id;
+
+#ifdef DEBUG
+ printf("SF: Got idcodes\n");
+ print_buffer(0, idcode, 1, sizeof(idcode), 0);
+#endif
+
+ /* count the number of continuation bytes */
+ for (shift = 0, idp = idcode;
+ shift < IDCODE_CONT_LEN && *idp == 0x7f;
+ ++shift, ++idp)
+ continue;
+
+ /* search the table for matches in shift and id */
+ for (i = 0; i < ARRAY_SIZE(flashes); ++i)
+ if (flashes[i].shift == shift && flashes[i].idcode == *idp) {
+ /* we have a match, call probe */
+ flash = flashes[i].probe(spi, idp);
+ if (flash)
+ break;
+ }
+
+ if (!flash) {
+ printf("SF: Unsupported manufacturer %02x\n", *idp);
+ goto err_manufacturer_probe;
+ }
+
+ printf("SF: Detected %s with total size ", flash->name);
+ print_size(flash->size, "");
+ puts("\n");
+
+ spi_release_bus(spi);
+
+ return flash;
+
+err_manufacturer_probe:
+err_read_id:
+ spi_release_bus(spi);
+err_claim_bus:
+ spi_free_slave(spi);
+ return NULL;
+}
+
+void spi_flash_free(struct spi_flash *flash)
+{
+ spi_free_slave(flash->spi);
+ free(flash);
+}
Code Review / kvmfornfv.git / blobdiff