From 5c92bf5dbb99d273d2ed343dbf3424f642637341 Mon Sep 17 00:00:00 2001
From: Greg Davill <greg.davill@gmail.com>
Date: Sun, 19 Apr 2020 13:08:15 +0930
Subject: [PATCH] update jtag_shift

---
 ecpprog.c  | 38 +++++++++++++++++++++++++++-----------
 jtag_tap.c | 32 ++++++++++++++++++++++++++++----
 mpsse.c    |  2 +-
 3 files changed, 56 insertions(+), 16 deletions(-)

diff --git a/ecpprog.c b/ecpprog.c
index 7c57209..72a9ce8 100644
--- a/ecpprog.c
+++ b/ecpprog.c
@@ -305,8 +305,9 @@ static void flash_read(int addr, uint8_t *data, int n)
 
 	//flash_chip_select();
 	//mpsse_send_spi(command, 4);
+	send_spi(command, 4);
 	memset(data, 0, n);
-	//mpsse_xfer_spi(data, n);
+	xfer_spi(data, n);
 	//flash_chip_deselect();
 
 	if (verbose)
@@ -405,18 +406,33 @@ uint8_t bit_reverse(uint8_t in){
 }
 
 void xfer_spi(uint8_t* data, uint32_t len){
-	/* Flip bit order of all bytes */
+	/* Reverse bit order of all bytes */
 	for(int i = 0; i < len; i++){
 		data[i] = bit_reverse(data[i]);
 	}
 
-	jtag_go_to_state(STATE_SHIFT_DR);
+	/* Don't switch states if we're already in SHIFT-DR */
+	if(jtag_current_state() != STATE_SHIFT_DR)
+		jtag_go_to_state(STATE_SHIFT_DR);
 	jtag_tap_shift(data, data, len * 8, true);
 
+	/* Reverse bit order of all return bytes */
+	for(int i = 0; i < len; i++){
+		data[i] = bit_reverse(data[i]);
+	}
+}
+
+void send_spi(uint8_t* data, uint32_t len){
+	uint8_t unused[len];
+	
 	/* Flip bit order of all bytes */
 	for(int i = 0; i < len; i++){
 		data[i] = bit_reverse(data[i]);
 	}
+
+	jtag_go_to_state(STATE_SHIFT_DR);
+	/* Stay in SHIFT-DR state, this keep CS low */
+	jtag_tap_shift(data, unused, len * 8, false); 
 }
 
 // ---------------------------------------------------------
@@ -920,20 +936,20 @@ int main(int argc, char **argv)
 	fprintf(stderr, "status..\n");
 	read_status_register();
 
+
+	/* Reset ECP5 to release SPI interface */
+	ecp_jtag_cmd(ISC_ENABLE);
+	ecp_jtag_cmd(ISC_ERASE);
+	ecp_jtag_cmd(ISC_DISABLE);
+
+	/* Put device into SPI bypass mode */
+	enter_spi_background_mode();
 	//usleep(20000);
 
 	if (test_mode)
 	{
 
 
-		/* Reset ECP5 to release SPI interface */
-		ecp_jtag_cmd(ISC_ENABLE);
-		ecp_jtag_cmd(ISC_ERASE);
-		ecp_jtag_cmd(ISC_DISABLE);
-
-		/* Put device into SPI bypass mode */
-		enter_spi_background_mode();
-
 		flash_reset();
 		flash_read_id();
 	}
diff --git a/jtag_tap.c b/jtag_tap.c
index 3775ca0..3402c5a 100644
--- a/jtag_tap.c
+++ b/jtag_tap.c
@@ -138,9 +138,9 @@ void jtag_init(void)
     jtag_go_to_state(STATE_TEST_LOGIC_RESET);
 }
 
-uint8_t data[1024];
+uint8_t data[32*1024];
 uint8_t* ptr;
-uint8_t rx_cnt;
+uint16_t rx_cnt;
 
 extern struct ftdi_context mpsse_ftdic;
 
@@ -153,14 +153,14 @@ static inline uint8_t jtag_pulse_clock_and_read_tdo(bool tms, bool tdi)
 	rx_cnt++;
 }
 
-
-void jtag_tap_shift(
+static void _jtag_tap_shift(
 	uint8_t *input_data,
 	uint8_t *output_data,
 	uint32_t data_bits,
 	bool must_end)
 {
 
+	//printf("_jtag_tap_shift(0x%08x,0x%08x,%u,%s);\n",input_data, output_data, data_bits, must_end ? "true" : "false");
 	uint32_t bit_count = data_bits;
 	uint32_t byte_count = (data_bits + 7) / 8;
 	rx_cnt = 0;
@@ -188,6 +188,30 @@ void jtag_tap_shift(
 		output_data[i] = data[7+i*8];
 }
 
+#define MIN(a,b) (a < b) ? a : b
+
+void jtag_tap_shift(
+	uint8_t *input_data,
+	uint8_t *output_data,
+	uint32_t data_bits,
+	bool must_end)
+{
+	uint32_t data_bits_sent = 0;
+	while(data_bits_sent != data_bits){
+
+		uint32_t _data_bits = MIN(256, data_bits);
+		bool last = (data_bits_sent + _data_bits) == data_bits;
+
+		_jtag_tap_shift(
+			input_data + data_bits_sent/8,
+			output_data + data_bits_sent/8,
+			_data_bits,
+			last & must_end
+		);
+		data_bits_sent += _data_bits;
+	}
+}
+
 void jtag_state_ack(bool tms)
 {
 	if (tms) {
diff --git a/mpsse.c b/mpsse.c
index 269d0da..1a942ec 100644
--- a/mpsse.c
+++ b/mpsse.c
@@ -244,7 +244,7 @@ void mpsse_init(int ifnum, const char *devstr, bool slow_clock)
 	} else {
 		// set 6 MHz clock
 		mpsse_send_byte(MC_SET_CLK_DIV);
-		mpsse_send_byte(5);
+		mpsse_send_byte(4);
 		mpsse_send_byte(0x00);
 	}
 }
-- 
2.30.2