drivers/siemens/nc_fpga: Add POST code over PCI
So far POST codes were mapped on IO port 0x80 inside the NC FPGA which
was connected via the LPC bus to the host CPU. On recent x86 generations
the LPC bus was replaced with eSPI and not all Siemens boards have the
eSPI routed to the NC FPGA. In order to have POST codes visible on those
boards the display is accessible via PCI in addition.
This patch adds the feature of sending the POST codes to the NC FPGA via
a PCI mapped register.
Change-Id: Ie15686de49cface17830365d78fe7c54cce183a0
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59346
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Mario Scheithauer <mario.scheithauer@siemens.com>
diff --git a/src/drivers/siemens/nc_fpga/nc_fpga_early.c b/src/drivers/siemens/nc_fpga/nc_fpga_early.c
new file mode 100644
index 0000000..6ec0349
--- /dev/null
+++ b/src/drivers/siemens/nc_fpga/nc_fpga_early.c
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <arch/mmio.h>
+#include <device/pci.h>
+#include <device/pci_def.h>
+#include <device/pci_ids.h>
+#include <device/pci_ops.h>
+#include <types.h>
+
+#include "nc_fpga.h"
+
+static DEVTREE_CONST uint32_t fpga_bar = CONFIG_EARLY_PCI_MMIO_BASE;
+static bool nc_fpga_present = false;
+
+int pci_early_device_probe(u8 bus, u8 dev, u32 mmio_base)
+{
+ pci_devfn_t pci_dev = PCI_DEV(bus, dev, 0);
+ uint32_t id = pci_s_read_config32(pci_dev, PCI_VENDOR_ID);
+
+ if (id != (0x4091 << 16 | PCI_VENDOR_ID_SIEMENS))
+ return -1;
+
+ /* Setup base address for BAR0. */
+ pci_s_write_config32(pci_dev, PCI_BASE_ADDRESS_0, mmio_base);
+ /* Enable memory access for pci_dev. */
+ u16 reg16 = pci_s_read_config16(pci_dev, PCI_COMMAND);
+ reg16 |= PCI_COMMAND_MEMORY;
+ pci_s_write_config16(pci_dev, PCI_COMMAND, reg16);
+ nc_fpga_present = true;
+
+ return 0;
+}
+
+void nc_fpga_remap(uint32_t new_mmio)
+{
+#if ENV_RAMSTAGE
+ fpga_bar = new_mmio;
+#endif
+}
+
+void nc_fpga_post(uint8_t value)
+{
+ /* The function pci_earyl_device_probe is called in bootblock and romstage. Make sure
+ that in these stages the initialization code was successful before the POST code
+ value is written to the register. */
+ if ((ENV_BOOTBLOCK || ENV_ROMSTAGE) && nc_fpga_present == false)
+ return;
+ write32((void *)(fpga_bar + NC_FPGA_POST_OFFSET), value);
+}