--- /dev/null
+/*
+ * Copyright © 2010 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.
+ */
+
+#include "ao.h"
+
+/* Total bytes of available storage */
+__xdata uint32_t ao_storage_total;
+
+/* Block size - device is erased in these units. At least 256 bytes */
+__xdata uint32_t ao_storage_block;
+
+/* Byte offset of config block. Will be ao_storage_block bytes long */
+__xdata uint32_t ao_storage_config;
+
+/* Storage unit size - device reads and writes must be within blocks of this size. Usually 256 bytes. */
+__xdata uint16_t ao_storage_unit;
+
+/*
+ * Each flash chip is arranged in 64kB sectors; the
+ * chip cannot erase in units smaller than that.
+ *
+ * Writing happens in units of 256 byte pages and
+ * can only change bits from 1 to 0. So, you can rewrite
+ * the same contents, or append to an existing page easily enough
+ */
+
+#define M25_WREN 0x06 /* Write Enable */
+#define M25_WRDI 0x04 /* Write Disable */
+#define M25_RDID 0x9f /* Read Identification */
+#define M25_RDSR 0x05 /* Read Status Register */
+#define M25_WRSR 0x01 /* Write Status Register */
+#define M25_READ 0x03 /* Read Data Bytes */
+#define M25_FAST_READ 0x0b /* Read Data Bytes at Higher Speed */
+#define M25_PP 0x02 /* Page Program */
+#define M25_SE 0xd8 /* Sector Erase */
+#define M25_BE 0xc7 /* Bulk Erase */
+#define M25_DP 0xb9 /* Deep Power-down */
+
+/* RDID response */
+#define M25_MANUF_OFFSET 0
+#define M25_MEMORY_TYPE_OFFSET 1
+#define M25_CAPACITY_OFFSET 2
+#define M25_UID_OFFSET 3
+#define M25_CFI_OFFSET 4
+#define M25_RDID_LEN 4 /* that's all we need */
+
+#define M25_CAPACITY_128KB 0x11
+#define M25_CAPACITY_256KB 0x12
+#define M25_CAPACITY_512KB 0x13
+#define M25_CAPACITY_1MB 0x14
+#define M25_CAPACITY_2MB 0x15
+
+/*
+ * Status register bits
+ */
+
+#define M25_STATUS_SRWD (1 << 7) /* Status register write disable */
+#define M25_STATUS_BP_MASK (7 << 2) /* Block protect bits */
+#define M25_STATUS_BP_SHIFT (2)
+#define M25_STATUS_WEL (1 << 1) /* Write enable latch */
+#define M25_STATUS_WIP (1 << 0) /* Write in progress */
+
+/*
+ * On teleterra, the m25 chip select pins are
+ * wired on P0_0 through P0_3.
+ */
+
+#if M25_MAX_CHIPS > 1
+static uint8_t ao_m25_size[M25_MAX_CHIPS]; /* number of sectors in each chip */
+static uint8_t ao_m25_pin[M25_MAX_CHIPS]; /* chip select pin for each chip */
+static uint8_t ao_m25_numchips; /* number of chips detected */
+#endif
+static uint8_t ao_m25_total; /* total sectors available */
+static uint8_t ao_m25_wip; /* write in progress */
+
+static __xdata uint8_t ao_m25_mutex;
+
+/*
+ * This little array is abused to send and receive data. A particular
+ * caution -- the read and write addresses are written into the last
+ * three bytes of the array by ao_m25_set_page_address and then the
+ * first byte is used by ao_m25_wait_wip and ao_m25_write_enable, neither
+ * of which touch those last three bytes.
+ */
+
+static __xdata uint8_t ao_m25_instruction[4];
+
+#define M25_SELECT(cs) (SPI_CS_PORT &= ~(cs))
+#define M25_DESELECT(cs) (SPI_CS_PORT |= (cs))
+
+#define M25_BLOCK_SHIFT 16
+#define M25_BLOCK 65536L
+#define M25_POS_TO_SECTOR(pos) ((uint8_t) ((pos) >> M25_BLOCK_SHIFT))
+#define M25_SECTOR_TO_POS(sector) (((uint32_t) (sector)) << M25_BLOCK_SHIFT)
+
+/*
+ * Block until the specified chip is done writing
+ */
+static void
+ao_m25_wait_wip(uint8_t cs)
+{
+ if (ao_m25_wip & cs) {
+ M25_SELECT(cs);
+ ao_m25_instruction[0] = M25_RDSR;
+ ao_spi_send(ao_m25_instruction, 1);
+ do {
+ ao_spi_recv(ao_m25_instruction, 1);
+ } while (ao_m25_instruction[0] & M25_STATUS_WIP);
+ M25_DESELECT(cs);
+ ao_m25_wip &= ~cs;
+ }
+}
+
+/*
+ * Set the write enable latch so that page program and sector
+ * erase commands will work. Also mark the chip as busy writing
+ * so that future operations will block until the WIP bit goes off
+ */
+static void
+ao_m25_write_enable(uint8_t cs)
+{
+ M25_SELECT(cs);
+ ao_m25_instruction[0] = M25_WREN;
+ ao_spi_send(&ao_m25_instruction, 1);
+ M25_DESELECT(cs);
+ ao_m25_wip |= cs;
+}
+
+
+/*
+ * Returns the number of 64kB sectors
+ */
+static uint8_t
+ao_m25_read_capacity(uint8_t cs)
+{
+ uint8_t capacity;
+ M25_SELECT(cs);
+ ao_m25_instruction[0] = M25_RDID;
+ ao_spi_send(ao_m25_instruction, 1);
+ ao_spi_recv(ao_m25_instruction, M25_RDID_LEN);
+ M25_DESELECT(cs);
+
+ /* Check to see if the chip is present */
+ if (ao_m25_instruction[0] == 0xff)
+ return 0;
+ capacity = ao_m25_instruction[M25_CAPACITY_OFFSET];
+
+ /* Sanity check capacity number */
+ if (capacity < 0x11 || 0x1f < capacity)
+ return 0;
+ return 1 << (capacity - 0x10);
+}
+
+static uint8_t
+ao_m25_set_address(uint32_t pos)
+{
+ uint8_t chip;
+#if M25_MAX_CHIPS > 1
+ uint8_t size;
+
+ for (chip = 0; chip < ao_m25_numchips; chip++) {
+ size = ao_m25_size[chip];
+ if (M25_POS_TO_SECTOR(pos) < size)
+ break;
+ pos -= M25_SECTOR_TO_POS(size);
+ }
+ if (chip == ao_m25_numchips)
+ return 0xff;
+
+ chip = ao_m25_pin[chip];
+#else
+ chip = M25_CS_MASK;
+#endif
+ ao_m25_wait_wip(chip);
+
+ ao_m25_instruction[1] = pos >> 16;
+ ao_m25_instruction[2] = pos >> 8;
+ ao_m25_instruction[3] = pos;
+ return chip;
+}
+
+/*
+ * Scan the possible chip select lines
+ * to see which flash chips are connected
+ */
+static uint8_t
+ao_m25_scan(void)
+{
+#if M25_MAX_CHIPS > 1
+ uint8_t pin, size;
+#endif
+
+ if (ao_m25_total)
+ return 1;
+
+#if M25_MAX_CHIPS > 1
+ ao_m25_numchips = 0;
+ for (pin = 1; pin != 0; pin <<= 1) {
+ if (M25_CS_MASK & pin) {
+ size = ao_m25_read_capacity(pin);
+ if (size != 0) {
+ ao_m25_size[ao_m25_numchips] = size;
+ ao_m25_pin[ao_m25_numchips] = pin;
+ ao_m25_total += size;
+ ao_m25_numchips++;
+ }
+ }
+ }
+#else
+ ao_m25_total = ao_m25_read_capacity(M25_CS_MASK);
+#endif
+ if (!ao_m25_total)
+ return 0;
+ ao_storage_total = M25_SECTOR_TO_POS(ao_m25_total);
+ ao_storage_block = M25_BLOCK;
+ ao_storage_config = ao_storage_total - M25_BLOCK;
+ ao_storage_unit = 256;
+ return 1;
+}
+
+/*
+ * Erase the specified sector
+ */
+uint8_t
+ao_storage_erase(uint32_t pos) __reentrant
+{
+ uint8_t cs;
+
+ if (pos >= ao_storage_total || pos + ao_storage_block > ao_storage_total)
+ return 0;
+
+ ao_mutex_get(&ao_m25_mutex);
+ ao_m25_scan();
+
+ cs = ao_m25_set_address(pos);
+
+ ao_m25_wait_wip(cs);
+ ao_m25_write_enable(cs);
+
+ ao_m25_instruction[0] = M25_SE;
+ M25_SELECT(cs);
+ ao_spi_send(ao_m25_instruction, 4);
+ M25_DESELECT(cs);
+ ao_m25_wip |= cs;
+
+ ao_mutex_put(&ao_m25_mutex);
+ return 1;
+}
+
+/*
+ * Write to flash
+ */
+uint8_t
+ao_storage_device_write(uint32_t pos, __xdata void *d, uint16_t len) __reentrant
+{
+ uint8_t cs;
+
+ if (pos >= ao_storage_total || pos + len > ao_storage_total)
+ return 0;
+
+ ao_mutex_get(&ao_m25_mutex);
+ ao_m25_scan();
+
+ cs = ao_m25_set_address(pos);
+ ao_m25_write_enable(cs);
+
+ ao_m25_instruction[0] = M25_PP;
+ M25_SELECT(cs);
+ ao_spi_send(ao_m25_instruction, 4);
+ ao_spi_send(d, len);
+ M25_DESELECT(cs);
+
+ ao_mutex_put(&ao_m25_mutex);
+ return 1;
+}
+
+/*
+ * Read from flash
+ */
+uint8_t
+ao_storage_device_read(uint32_t pos, __xdata void *d, uint16_t len) __reentrant
+{
+ uint8_t cs;
+
+ if (pos >= ao_storage_total || pos + len > ao_storage_total)
+ return 0;
+ ao_mutex_get(&ao_m25_mutex);
+ ao_m25_scan();
+
+ cs = ao_m25_set_address(pos);
+
+ /* No need to use the FAST_READ as we're running at only 8MHz */
+ ao_m25_instruction[0] = M25_READ;
+ M25_SELECT(cs);
+ ao_spi_send(ao_m25_instruction, 4);
+ ao_spi_recv(d, len);
+ M25_DESELECT(cs);
+
+ ao_mutex_put(&ao_m25_mutex);
+ return 1;
+}
+
+void
+ao_storage_flush(void) __reentrant
+{
+}
+
+void
+ao_storage_setup(void)
+{
+ ao_mutex_get(&ao_m25_mutex);
+ ao_m25_scan();
+ ao_mutex_put(&ao_m25_mutex);
+}
+
+void
+ao_storage_device_info(void) __reentrant
+{
+ uint8_t cs;
+#if M25_MAX_CHIPS > 1
+ uint8_t chip;
+#endif
+
+ ao_mutex_get(&ao_m25_mutex);
+ ao_m25_scan();
+ ao_mutex_put(&ao_m25_mutex);
+
+#if M25_MAX_CHIPS > 1
+ printf ("Detected chips %d size %d\n", ao_m25_numchips, ao_m25_total);
+ for (chip = 0; chip < ao_m25_numchips; chip++)
+ printf ("Flash chip %d select %02x size %d\n",
+ chip, ao_m25_pin[chip], ao_m25_size[chip]);
+#else
+ printf ("Detected chips 1 size %d\n", ao_m25_total);
+#endif
+
+ printf ("Available chips:\n");
+ for (cs = 1; cs != 0; cs <<= 1) {
+ if ((M25_CS_MASK & cs) == 0)
+ continue;
+
+ ao_mutex_get(&ao_m25_mutex);
+ M25_SELECT(cs);
+ ao_m25_instruction[0] = M25_RDID;
+ ao_spi_send(ao_m25_instruction, 1);
+ ao_spi_recv(ao_m25_instruction, M25_RDID_LEN);
+ M25_DESELECT(cs);
+
+ printf ("Select %02x manf %02x type %02x cap %02x uid %02x\n",
+ cs,
+ ao_m25_instruction[M25_MANUF_OFFSET],
+ ao_m25_instruction[M25_MEMORY_TYPE_OFFSET],
+ ao_m25_instruction[M25_CAPACITY_OFFSET],
+ ao_m25_instruction[M25_UID_OFFSET]);
+ ao_mutex_put(&ao_m25_mutex);
+ }
+}
+
+void
+ao_storage_device_init(void)
+{
+ /* Set up chip select wires */
+ SPI_CS_PORT |= M25_CS_MASK; /* raise all CS pins */
+ SPI_CS_DIR |= M25_CS_MASK; /* set CS pins as outputs */
+ SPI_CS_SEL &= ~M25_CS_MASK; /* set CS pins as GPIO */
+}
projects / fw / altos / blobdiff