Merge branch 'lukeshu/dma'

1 files changed, 22 insertions, 3 deletions

diff --git a/libhw/w5500.c b/libhw/w5500.c
index b4ad86b..c4d36f3 100644
--- a/libhw/w5500.c
+++ b/libhw/w5500.c
@@ -96,6 +96,9 @@
 #ifndef CONFIG_W5500_LOCAL_PORT_MAX
 	#error config.h must define CONFIG_W5500_LOCAL_PORT_MAX
 #endif
+#ifndef CONFIG_W5500_VALIDATE_SPI
+	#error config.h must define CONFIG_W5500_VALIDATE_SPI
+#endif
 #ifndef CONFIG_W5500_DEBUG
 	#error config.h must define CONFIG_W5500_DEBUG
 #endif
@@ -312,6 +315,22 @@ void _w5500_init(struct w5500 *chip,
 		};
 	}
 
+#if CONFIG_W5500_VALIDATE_SPI
+	/* Validate that SPI works correctly.  */
+	bool spi_ok = true;
+	for (uint16_t a = 0; a < 0x100; a++) {
+		w5500ll_write_sock_reg(chip->spidev, 0, mode, a);
+		uint8_t b = w5500ll_read_sock_reg(chip->spidev, 0, mode);
+		if (b != a) {
+			errorf("SPI to W5500 does not appear to be functional: wrote:0x%02"PRIx16" != read:0x%02"PRIx8, a, b);
+			spi_ok = false;
+		}
+	}
+	if (!spi_ok)
+		__lm_abort();
+	w5500ll_write_sock_reg(chip->spidev, 0, mode, 0);
+#endif
+
 	/* Initialize the hardware.  */
 	gpioirq_set_and_enable_exclusive_handler(pin_intr, GPIO_IRQ_EDGE_FALL, w5500_intrhandler, chip);
 	gpio_set_dir(chip->pin_reset, GPIO_OUT);
@@ -329,9 +348,9 @@ static void w5500_post_reset(struct w5500 *chip) {
 	w5500ll_write_common_reg(chip->spidev, eth_addr, chip->hwaddr);
 
 	/* The RP2040 needs a 1/sys_clk hysteresis between interrupts
-	 * for us to notice them.  At the maximum-rated clock-rate of
-	 * 133MHz, that means 7.5ns (but the sbc-harness overclocks
-	 * the RP2040, so we could get away with even shorter).
+	 * for us to notice them.  At the default clock-rate of
+	 * 125MHz, that means 8ns; and at the maximum-rated clock-rate
+	 * of 200MHz, that means 5ns.
 	 *
 	 * If intlevel is non-zero, then the hysteresis is
 	 * (intlevel+1)*4/(150MHz), or (intlevel+1)*26.7ns; so even