diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/sh/drivers/pci/fixups-sdk7786.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/sh/drivers/pci/fixups-sdk7786.c')
-rw-r--r-- | arch/sh/drivers/pci/fixups-sdk7786.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/sh/drivers/pci/fixups-sdk7786.c b/arch/sh/drivers/pci/fixups-sdk7786.c new file mode 100644 index 0000000000..6972af7b4e --- /dev/null +++ b/arch/sh/drivers/pci/fixups-sdk7786.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * SDK7786 FPGA PCIe mux handling + * + * Copyright (C) 2010 Paul Mundt + */ +#define pr_fmt(fmt) "PCI: " fmt + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/pci.h> +#include <mach/fpga.h> + +/* + * The SDK7786 FPGA supports mangling of most of the slots in some way or + * another. Slots 3/4 are special in that only one can be supported at a + * time, and both appear on port 3 to the PCI bus scan. Enabling slot 4 + * (the horizontal edge connector) will disable slot 3 entirely. + * + * Misconfigurations can be detected through the FPGA via the slot + * resistors to determine card presence. Hotplug remains unsupported. + */ +static unsigned int slot4en __initdata; + +char *__init pcibios_setup(char *str) +{ + if (strcmp(str, "slot4en") == 0) { + slot4en = 1; + return NULL; + } + + return str; +} + +static int __init sdk7786_pci_init(void) +{ + u16 data = fpga_read_reg(PCIECR); + + /* + * Enable slot #4 if it's been specified on the command line. + * + * Optionally reroute if slot #4 has a card present while slot #3 + * does not, regardless of command line value. + * + * Card presence is logically inverted. + */ + slot4en ?: (!(data & PCIECR_PRST4) && (data & PCIECR_PRST3)); + if (slot4en) { + pr_info("Activating PCIe slot#4 (disabling slot#3)\n"); + + data &= ~PCIECR_PCIEMUX1; + fpga_write_reg(data, PCIECR); + + /* Warn about forced rerouting if slot#3 is occupied */ + if ((data & PCIECR_PRST3) == 0) { + pr_warn("Unreachable card detected in slot#3\n"); + return -EBUSY; + } + } else + pr_info("PCIe slot#4 disabled\n"); + + return 0; +} +postcore_initcall(sdk7786_pci_init); |