Update SPI flash driver for new QSPI core

Signed-off-by: gatecat <gatecat@ds0.me>

Author: gatecat

chipflow_lib/software/drivers/spiflash.S

@@ -1,67 +1,57 @@
-
 .global flashio_worker_begin
 .global flashio_worker_end
 
 .balign 4
 
 flashio_worker_begin:
-# a0 ... address of SPI ctrl reg
+# a0 ... flash base address
 # a1 ... data pointer
 # a2 ... data length
 # a3 ... optional WREN cmd (0 = disable)
 
-# Set CS high, IO0 is output
-li   t1, 0x120
-sh   t1, 0(a0)
-
-# Enable Manual SPI Ctrl
-sb   zero, 3(a0)
-
-# Send optional WREN cmd
-beqz a3, flashio_worker_L1
-li   t5, 8
-andi t2, a3, 0xff
-flashio_worker_L4:
-srli t4, t2, 7
-sb   t4, 0(a0)
-ori  t4, t4, 0x10
-sb   t4, 0(a0)
-slli t2, t2, 1
-andi t2, t2, 0xff
-addi t5, t5, -1
-bnez t5, flashio_worker_L4
-sb   t1, 0(a0)
-
-# SPI transfer
-flashio_worker_L1:
-beqz a2, flashio_worker_L3
-li   t5, 8
-lbu  t2, 0(a1)
-flashio_worker_L2:
-srli t4, t2, 7
-sb   t4, 0(a0)
-ori  t4, t4, 0x10
-sb   t4, 0(a0)
-lbu  t4, 0(a0)
-andi t4, t4, 2
-srli t4, t4, 1
-slli t2, t2, 1
-or   t2, t2, t4
-andi t2, t2, 0xff
-addi t5, t5, -1
-bnez t5, flashio_worker_L2
-sb   t2, 0(a1)
+mv t3, ra
+
+# address of SPI ctrl reg
+li   a0, 0xb0000000
+# enter bypass mode
+lbu   t1, 0(a0) 
+ori   t1, t1, 0x1
+sb    t1, 0(a0)
+call flashio_wait_bypass_ready
+
+beqz a3, flashio_xfer
+
+sb a3, 8(a0) # send wren
+call flashio_wait_bypass_ready
+li t1, 2 # deselect
+sb t1, 4(a0)
+call flashio_wait_bypass_ready
+
+flashio_xfer:
+beqz a2, flashio_done
+lbu t1, 0(a1)
+sb t1, 8(a0) # tx data
+call flashio_wait_bypass_ready
+lbu t1, 12(a0) # rx data
+sb t1, 0(a1)
 addi a1, a1, 1
 addi a2, a2, -1
-j    flashio_worker_L1
-flashio_worker_L3:
+j flashio_xfer
 
-# Back to MEMIO mode
-li   t1, 0x80
-sb   t1, 3(a0)
+flashio_done:
+# exit bypass mode
+lbu   t1, 0(a0) 
+andi   t1, t1, 0xFE
+sb    t1, 0(a0)
 
 fence.i
+mv ra, t3
+ret
 
+flashio_wait_bypass_ready:
+lbu   t1, 4(a0)
+andi t1, t1, 0x1
+beqz t1, flashio_wait_bypass_ready
 ret
 
 .balign 4

chipflow_lib/software/drivers/spiflash.c

@@ -7,17 +7,18 @@ extern uint32_t flashio_worker_end;
 
 void spiflash_io(volatile spiflash_regs_t *flash, uint8_t *data, int len, uint8_t wrencmd) {
 	// Flash can't be accessed during IO, so copy to RAM and run that
-	volatile uint32_t func[&flashio_worker_end - &flashio_worker_begin];
+    volatile uint32_t func[&flashio_worker_end - &flashio_worker_begin];
 
-	uint32_t *src_ptr = &flashio_worker_begin;
-	volatile uint32_t *dst_ptr = func;
+    // Can't execute off flash while talking to it, so copy IO code to SRAM
+    uint32_t *src_ptr = &flashio_worker_begin;
+    volatile uint32_t *dst_ptr = func;
 
-	while (src_ptr != &flashio_worker_end)
-		*(dst_ptr++) = *(src_ptr++);
+    while (src_ptr != &flashio_worker_end)
+        *(dst_ptr++) = *(src_ptr++);
 
-	__asm__ volatile ("fence.i" : : : "memory");
+    __asm__ volatile ("fence.i" : : : "memory");
 
-	((void(*)(volatile spiflash_regs_t *, uint8_t*, uint32_t, uint32_t))func)(flash, data, len, wrencmd);
+    ((void(*)(uint8_t*, uint8_t*, uint32_t, uint32_t))func)((uint8_t*)flash, data, len, wrencmd);
 }
 
 uint32_t spiflash_read_id(volatile spiflash_regs_t *flash) {
@@ -69,5 +70,5 @@ void spiflash_set_qspi_flag(volatile spiflash_regs_t *flash) {
 }
 
 void spiflash_set_quad_mode(volatile spiflash_regs_t *flash) {
-	flash->ctrl = (flash->ctrl & ~0x007f0000) | 0x00240000;
+    flash->config = (0x3U << 3U) | (0x03U << 1U); // 3 dummy byte, X4 mode
 }

chipflow_lib/software/drivers/spiflash.h

@@ -8,7 +8,10 @@
 #define ISSI_ID 0x60
 
 typedef struct __attribute__((packed, aligned(4))) {
-	uint32_t ctrl;
+    uint32_t config;
+    uint32_t raw_control;
+    uint32_t raw_tx_data;
+    uint32_t raw_rx_data;
 } spiflash_regs_t;
 
 void spiflash_io(volatile spiflash_regs_t *flash, uint8_t *data, int len, uint8_t wrencmd);