From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Fri, 9 Aug 2019 08:31:53 +0000 (+0200)
Subject: software/libase/mdio: cleanup and reduce raw_turnaround by 1 cycle
X-Git-Tag: 24jan2021_ls180~1056
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6d94c07d70bd2ea7ae6db8958b5ae13131d1af97;p=litex.git

software/libase/mdio: cleanup and reduce raw_turnaround by 1 cycle
---

diff --git a/litex/soc/software/include/base/mdio.h b/litex/soc/software/include/base/mdio.h
index 875e53c5..bffa5a63 100644
--- a/litex/soc/software/include/base/mdio.h
+++ b/litex/soc/software/include/base/mdio.h
@@ -7,6 +7,12 @@
 
 #define MDIO_DI	0x01
 
+#define MDIO_PREAMBLE    0xffffffff
+#define MDIO_START       0x1
+#define MDIO_READ        0x2
+#define MDIO_WRITE       0x1
+#define MDIO_TURN_AROUND 0x2
+
 void mdio_write(int phyadr, int reg, int val);
 int mdio_read(int phyadr, int reg);
 
diff --git a/litex/soc/software/libbase/mdio.c b/litex/soc/software/libbase/mdio.c
index 97487348..362e274c 100644
--- a/litex/soc/software/libbase/mdio.c
+++ b/litex/soc/software/libbase/mdio.c
@@ -7,7 +7,8 @@
 
 static void delay(void)
 {
-/* no delay FIXME */
+	volatile int i;
+	for(i=0;i<100;i++);
 }
 
 static void raw_write(unsigned int word, int bitcount)
@@ -54,20 +55,17 @@ static void raw_turnaround(void)
 	delay();
 	ethphy_mdio_w_write(0);
 	delay();
-	ethphy_mdio_w_write(MDIO_CLK);
-	delay();
-	ethphy_mdio_w_write(0);
-	delay();
 }
 
 void mdio_write(int phyadr, int reg, int val)
 {
 	ethphy_mdio_w_write(MDIO_OE);
-	raw_write(0xffffffff, 32); /* < sync */
-	raw_write(0x05, 4); /* < start + write */
+	raw_write(MDIO_PREAMBLE, 32);
+	raw_write(MDIO_START, 2);
+	raw_write(MDIO_WRITE, 2);
 	raw_write(phyadr, 5);
 	raw_write(reg, 5);
-	raw_write(0x02, 2); /* < turnaround */
+	raw_write(MDIO_TURN_AROUND, 2);
 	raw_write(val, 16);
 	raw_turnaround();
 }
@@ -77,8 +75,9 @@ int mdio_read(int phyadr, int reg)
 	int r;
 
 	ethphy_mdio_w_write(MDIO_OE);
-	raw_write(0xffffffff, 32); /* < sync */
-	raw_write(0x06, 4); /* < start + read */
+	raw_write(MDIO_PREAMBLE, 32);
+	raw_write(MDIO_START, 2);
+	raw_write(MDIO_READ, 2);
 	raw_write(phyadr, 5);
 	raw_write(reg, 5);
 	raw_turnaround();