kernel/spec: reset FPGA after reprogramming

Actually, Tom suggsted the fix and he's the author, but the swearing
is mine and I'd better get authorship for my complaints.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

kernel/spec-fmc.c

@@ -40,6 +40,7 @@ static int spec_reprogram(struct fmc_device *fmc, struct fmc_driver *drv,
 	const struct firmware *fw;
 	struct spec_dev *spec = fmc->carrier_data;
 	struct device *dev = fmc->hwdev;
+	uint32_t reg;
 	int ret;
 
 	if (!gw)
@@ -73,7 +74,15 @@ static int spec_reprogram(struct fmc_device *fmc, struct fmc_driver *drv,
 	else
 		fmc->flags |= FMC_DEVICE_HAS_CUSTOM;
 
-	/* FIXME: load lm32 */
+	/* After reprogramming, reset the FPGA using the gennum register */
+	reg = gennum_readl(spec, GNPCI_SYS_CFG_SYSTEM);
+	/*
+	 * This _fucking_ register must be written with extreme care,
+	 * becase some fields are "protected" and some are not. *hate*
+	 */
+	gennum_writel(spec, (reg & ~0xffff) | 0x3fff, GNPCI_SYS_CFG_SYSTEM);
+	gennum_writel(spec, (reg & ~0xffff) | 0x7fff, GNPCI_SYS_CFG_SYSTEM);
+
 out:
 	release_firmware(fw);
 	return ret;

kernel/spec.h

@@ -47,6 +47,8 @@ enum {
 	GNPPCI_MSI_ADDRESS_HIGH	= 0x50,
 	GNPPCI_MSI_DATA		= 0x54,
 
+	GNPCI_SYS_CFG_SYSTEM	= 0x800,
+
 	/* page 130 ff */
 	GNINT_CTRL		= 0x810,
 	GNINT_STAT		= 0x814,