--- /dev/null
+/*
+ * Copyright © 2009 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; 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.
+ */
+
+#include "ao.h"
+#include "25lc1024.h"
+
+/*
+ * Using SPI on USART 0, with P1_2 as the chip select
+ */
+
+#define EE_CS P1_2
+#define EE_CS_INDEX 2
+
+__xdata uint8_t ao_ee_dma_in_done;
+__xdata uint8_t ao_ee_dma_out_done;
+__xdata uint8_t ao_ee_mutex;
+
+uint8_t ao_ee_dma_out_id;
+uint8_t ao_ee_dma_in_id;
+
+static __xdata uint8_t ao_ee_const = 0xff;
+
+#define ao_ee_delay() do { \
+ _asm nop _endasm; \
+ _asm nop _endasm; \
+ _asm nop _endasm; \
+} while(0)
+
+void ao_ee_cs_low(void)
+{
+ ao_ee_delay();
+ EE_CS = 0;
+ ao_ee_delay();
+}
+
+void ao_ee_cs_high(void)
+{
+ ao_ee_delay();
+ EE_CS = 1;
+ ao_ee_delay();
+}
+
+/* Send bytes over SPI.
+ *
+ * This sets up two DMA engines, one writing the data and another reading
+ * bytes coming back. We use the bytes coming back to tell when the transfer
+ * is complete, as the transmit register is double buffered and hence signals
+ * completion one byte before the transfer is actually complete
+ */
+static void
+ao_ee_send(void __xdata *block, uint16_t len)
+{
+ ao_dma_set_transfer(ao_ee_dma_in_id,
+ &U0DBUFXADDR,
+ &ao_ee_const,
+ len,
+ DMA_CFG0_WORDSIZE_8 |
+ DMA_CFG0_TMODE_SINGLE |
+ DMA_CFG0_TRIGGER_URX0,
+ DMA_CFG1_SRCINC_0 |
+ DMA_CFG1_DESTINC_0 |
+ DMA_CFG1_PRIORITY_NORMAL);
+
+ ao_dma_set_transfer(ao_ee_dma_out_id,
+ block,
+ &U0DBUFXADDR,
+ len,
+ DMA_CFG0_WORDSIZE_8 |
+ DMA_CFG0_TMODE_SINGLE |
+ DMA_CFG0_TRIGGER_UTX0,
+ DMA_CFG1_SRCINC_1 |
+ DMA_CFG1_DESTINC_0 |
+ DMA_CFG1_PRIORITY_NORMAL);
+
+ ao_dma_start(ao_ee_dma_in_id);
+ ao_dma_start(ao_ee_dma_out_id);
+ ao_dma_trigger(ao_ee_dma_out_id);
+ __critical while (!ao_ee_dma_in_done)
+ ao_sleep(&ao_ee_dma_in_done);
+}
+
+/* Receive bytes over SPI.
+ *
+ * This sets up tow DMA engines, one reading the data and another
+ * writing constant values to the SPI transmitter as that is what
+ * clocks the data coming in.
+ */
+static void
+ao_ee_recv(void __xdata *block, uint16_t len)
+{
+ ao_dma_set_transfer(ao_ee_dma_in_id,
+ &U0DBUFXADDR,
+ block,
+ len,
+ DMA_CFG0_WORDSIZE_8 |
+ DMA_CFG0_TMODE_SINGLE |
+ DMA_CFG0_TRIGGER_URX0,
+ DMA_CFG1_SRCINC_0 |
+ DMA_CFG1_DESTINC_1 |
+ DMA_CFG1_PRIORITY_NORMAL);
+
+ ao_dma_set_transfer(ao_ee_dma_out_id,
+ &ao_ee_const,
+ &U0DBUFXADDR,
+ len,
+ DMA_CFG0_WORDSIZE_8 |
+ DMA_CFG0_TMODE_SINGLE |
+ DMA_CFG0_TRIGGER_UTX0,
+ DMA_CFG1_SRCINC_0 |
+ DMA_CFG1_DESTINC_0 |
+ DMA_CFG1_PRIORITY_NORMAL);
+
+ ao_dma_start(ao_ee_dma_in_id);
+ ao_dma_start(ao_ee_dma_out_id);
+ ao_dma_trigger(ao_ee_dma_out_id);
+ __critical while (!ao_ee_dma_in_done)
+ ao_sleep(&ao_ee_dma_in_done);
+}
+
+#define EE_BLOCK 256
+
+struct ao_ee_instruction {
+ uint8_t instruction;
+ uint8_t address[3];
+} __xdata ao_ee_instruction;
+
+static void
+ao_ee_write_enable(void)
+{
+ ao_ee_cs_low();
+ ao_ee_instruction.instruction = EE_WREN;
+ ao_ee_send(&ao_ee_instruction, 1);
+ ao_ee_cs_high();
+}
+
+static uint8_t
+ao_ee_rdsr(void)
+{
+ ao_ee_cs_low();
+ ao_ee_instruction.instruction = EE_RDSR;
+ ao_ee_send(&ao_ee_instruction, 1);
+ ao_ee_recv(&ao_ee_instruction, 1);
+ ao_ee_cs_high();
+ return ao_ee_instruction.instruction;
+}
+
+static void
+ao_ee_wrsr(uint8_t status)
+{
+ ao_ee_cs_low();
+ ao_ee_instruction.instruction = EE_WRSR;
+ ao_ee_instruction.address[0] = status;
+ ao_ee_send(&ao_ee_instruction, 2);
+ ao_ee_cs_high();
+}
+
+#define EE_BLOCK_NONE 0xffff
+
+__xdata uint8_t ao_ee_data[EE_BLOCK];
+__data uint16_t ao_ee_block = EE_BLOCK_NONE;
+__data uint8_t ao_ee_block_dirty;
+
+/* Write the current block to the EEPROM */
+static void
+ao_ee_write_block(void)
+{
+ uint8_t status;
+
+ status = ao_ee_rdsr();
+ if (status & (EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN)) {
+ status &= ~(EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN);
+ ao_ee_wrsr(status);
+ }
+ ao_ee_write_enable();
+ ao_ee_cs_low();
+ ao_ee_instruction.instruction = EE_WRITE;
+ ao_ee_instruction.address[0] = ao_ee_block >> 8;
+ ao_ee_instruction.address[1] = ao_ee_block;
+ ao_ee_instruction.address[2] = 0;
+ ao_ee_send(&ao_ee_instruction, 4);
+ ao_ee_send(ao_ee_data, EE_BLOCK);
+ ao_ee_cs_high();
+ for (;;) {
+ uint8_t status = ao_ee_rdsr();
+ if ((status & EE_STATUS_WIP) == 0)
+ break;
+ }
+}
+
+/* Read the current block from the EEPROM */
+static void
+ao_ee_read_block(void)
+{
+ ao_ee_cs_low();
+ ao_ee_instruction.instruction = EE_READ;
+ ao_ee_instruction.address[0] = ao_ee_block >> 8;
+ ao_ee_instruction.address[1] = ao_ee_block;
+ ao_ee_instruction.address[2] = 0;
+ ao_ee_send(&ao_ee_instruction, 4);
+ ao_ee_recv(ao_ee_data, EE_BLOCK);
+ ao_ee_cs_high();
+}
+
+void
+ao_ee_flush(void)
+{
+ if (ao_ee_block_dirty) {
+ ao_ee_write_block();
+ ao_ee_block_dirty = 0;
+ }
+}
+
+static void
+ao_ee_fill(uint16_t block)
+{
+ if (block != ao_ee_block) {
+ ao_ee_flush();
+ ao_ee_block = block;
+ ao_ee_read_block();
+ }
+}
+
+uint8_t
+ao_ee_write(uint32_t pos, uint8_t *buf, uint16_t len)
+{
+ uint16_t block;
+ uint16_t this_len;
+ uint8_t this_off;
+
+ if (pos >= AO_EE_DATA_SIZE || pos + len > AO_EE_DATA_SIZE)
+ return 0;
+ while (len) {
+
+ /* Compute portion of transfer within
+ * a single block
+ */
+ this_off = pos;
+ this_len = 256 - (uint16_t) this_off;
+ block = (uint16_t) (pos >> 8);
+ if (this_len > len)
+ this_len = len;
+ if (this_len & 0xff00)
+ ao_panic(AO_PANIC_EE);
+
+ /* Transfer the data */
+ ao_mutex_get(&ao_ee_mutex); {
+ if (this_len != 256)
+ ao_ee_fill(block);
+ else {
+ ao_ee_flush();
+ ao_ee_block = block;
+ }
+ memcpy(ao_ee_data + this_off, buf, this_len);
+ ao_ee_block_dirty = 1;
+ } ao_mutex_put(&ao_ee_mutex);
+
+ /* See how much is left */
+ buf += this_len;
+ len -= this_len;
+ }
+ return 1;
+}
+
+uint8_t
+ao_ee_read(uint32_t pos, uint8_t *buf, uint16_t len)
+{
+ uint16_t block;
+ uint16_t this_len;
+ uint8_t this_off;
+
+ if (pos >= AO_EE_DATA_SIZE || pos + len > AO_EE_DATA_SIZE)
+ return 0;
+ while (len) {
+
+ /* Compute portion of transfer within
+ * a single block
+ */
+ this_off = pos;
+ this_len = 256 - (uint16_t) this_off;
+ block = (uint16_t) (pos >> 8);
+ if (this_len > len)
+ this_len = len;
+ if (this_len & 0xff00)
+ ao_panic(AO_PANIC_EE);
+
+ /* Transfer the data */
+ ao_mutex_get(&ao_ee_mutex); {
+ ao_ee_fill(block);
+ memcpy(buf, ao_ee_data + this_off, this_len);
+ } ao_mutex_put(&ao_ee_mutex);
+
+ /* See how much is left */
+ buf += this_len;
+ len -= this_len;
+ }
+ return 1;
+}
+
+/*
+ * Read/write the config block, which is in
+ * the last block of the ao_eeprom
+ */
+uint8_t
+ao_ee_write_config(uint8_t *buf, uint16_t len)
+{
+ if (len > AO_EE_BLOCK_SIZE)
+ return 0;
+ ao_mutex_get(&ao_ee_mutex); {
+ ao_ee_fill(AO_EE_CONFIG_BLOCK);
+ memcpy(ao_ee_data, buf, len);
+ ao_ee_block_dirty = 1;
+ } ao_mutex_put(&ao_ee_mutex);
+ return 1;
+}
+
+uint8_t
+ao_ee_read_config(uint8_t *buf, uint16_t len)
+{
+ if (len > AO_EE_BLOCK_SIZE)
+ return 0;
+ ao_mutex_get(&ao_ee_mutex); {
+ ao_ee_fill(AO_EE_CONFIG_BLOCK);
+ memcpy(buf, ao_ee_data, len);
+ } ao_mutex_put(&ao_ee_mutex);
+ return 1;
+}
+
+/*
+ * To initialize the chip, set up the CS line and
+ * the SPI interface
+ */
+void
+ao_ee_init(void)
+{
+ /* set up CS */
+ EE_CS = 1;
+ P1DIR |= (1 << EE_CS_INDEX);
+ P1SEL &= ~(1 << EE_CS_INDEX);
+
+ /* Set up the USART pin assignment */
+ PERCFG = (PERCFG & ~PERCFG_U0CFG_ALT_MASK) | PERCFG_U0CFG_ALT_2;
+
+ /* Ensure that USART0 takes precidence over USART1 for pins that
+ * they share
+ */
+ P2SEL = (P2SEL & ~P2SEL_PRI3P1_MASK) | P2SEL_PRI3P1_USART0;
+
+ /* Make the SPI pins be controlled by the USART peripheral */
+ P1SEL |= ((1 << 5) | (1 << 4) | (1 << 3));
+
+ /* Set up OUT DMA */
+ ao_ee_dma_out_id = ao_dma_alloc(&ao_ee_dma_out_done);
+
+ /* Set up IN DMA */
+ ao_ee_dma_in_id = ao_dma_alloc(&ao_ee_dma_in_done);
+
+ /* Set up the USART.
+ *
+ * SPI master mode
+ */
+ U0CSR = (UxCSR_MODE_SPI | UxCSR_RE | UxCSR_MASTER);
+
+ /* Set the baud rate and signal parameters
+ *
+ * The cc1111 is limited to a 24/8 MHz SPI clock,
+ * while the 25LC1024 is limited to 20MHz. So,
+ * use the 3MHz clock (BAUD_E 17, BAUD_M 0)
+ */
+ U0BAUD = 0;
+ U0GCR = (UxGCR_CPOL_NEGATIVE |
+ UxGCR_CPHA_FIRST_EDGE |
+ UxGCR_ORDER_MSB |
+ (17 << UxGCR_BAUD_E_SHIFT));
+}