[PATCH v6 089/102] x86: apl: Add hostbridge driver
Simon Glass
sjg at chromium.org
Sat Dec 7 05:43:02 CET 2019
This driver models the hostbridge as a northbridge. It simply sets up the
graphics BAR. It supports of-platdata.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v6:
- Fix comments for struct apl_hostbridge_platdata
Changes in v5: None
Changes in v4:
- Avoid needing to know internals of pinctrl in this driver
- Move code to pinctrl driver
- Switch over to use pinctrl for pad init/config
Changes in v3:
- Move pad programming into the hostbridge to reduce TPL device-tree size
- Use pci_get_devfn()
Changes in v2: None
arch/x86/cpu/apollolake/Makefile | 1 +
arch/x86/cpu/apollolake/hostbridge.c | 179 +++++++++++++++++++++++++++
2 files changed, 180 insertions(+)
create mode 100644 arch/x86/cpu/apollolake/hostbridge.c
diff --git a/arch/x86/cpu/apollolake/Makefile b/arch/x86/cpu/apollolake/Makefile
index 3a8c2f66a3..4d3c08f84e 100644
--- a/arch/x86/cpu/apollolake/Makefile
+++ b/arch/x86/cpu/apollolake/Makefile
@@ -4,5 +4,6 @@
obj-$(CONFIG_SPL_BUILD) += systemagent.o
+obj-y += hostbridge.o
obj-y += pmc.o
obj-y += uart.o
diff --git a/arch/x86/cpu/apollolake/hostbridge.c b/arch/x86/cpu/apollolake/hostbridge.c
new file mode 100644
index 0000000000..793853d5b5
--- /dev/null
+++ b/arch/x86/cpu/apollolake/hostbridge.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dt-structs.h>
+#include <spl.h>
+#include <asm/intel_pinctrl.h>
+#include <asm/intel_regs.h>
+#include <asm/pci.h>
+#include <asm/arch/systemagent.h>
+
+/**
+ * struct apl_hostbridge_platdata - platform data for hostbridge
+ *
+ * @dtplat: Platform data for of-platdata
+ * @early_pads: Early pad data to set up, each (pad, cfg0, cfg1)
+ * @early_pads_count: Number of pads to process
+ * @pciex_region_size: BAR length in bytes
+ * @bdf: Bus/device/function of hostbridge
+ */
+struct apl_hostbridge_platdata {
+#if CONFIG_IS_ENABLED(OF_PLATDATA)
+ struct dtd_intel_apl_hostbridge dtplat;
+#endif
+ u32 *early_pads;
+ int early_pads_count;
+ uint pciex_region_size;
+ pci_dev_t bdf;
+};
+
+enum {
+ PCIEXBAR = 0x60,
+ PCIEXBAR_LENGTH_256MB = 0,
+ PCIEXBAR_LENGTH_128MB,
+ PCIEXBAR_LENGTH_64MB,
+
+ PCIEXBAR_PCIEXBAREN = 1 << 0,
+
+ TSEG = 0xb8, /* TSEG base */
+};
+
+static int apl_hostbridge_early_init_pinctrl(struct udevice *dev)
+{
+ struct apl_hostbridge_platdata *plat = dev_get_platdata(dev);
+ struct udevice *pinctrl;
+ int ret;
+
+ ret = uclass_first_device_err(UCLASS_PINCTRL, &pinctrl);
+ if (ret)
+ return log_msg_ret("no hostbridge pinctrl", ret);
+
+ return pinctrl_config_pads(pinctrl, plat->early_pads,
+ plat->early_pads_count);
+}
+
+static int apl_hostbridge_early_init(struct udevice *dev)
+{
+ struct apl_hostbridge_platdata *plat = dev_get_platdata(dev);
+ u32 region_size;
+ ulong base;
+ u32 reg;
+ int ret;
+
+ /* Set up the MCHBAR */
+ pci_x86_read_config(plat->bdf, MCHBAR, &base, PCI_SIZE_32);
+ base = MCH_BASE_ADDRESS;
+ pci_x86_write_config(plat->bdf, MCHBAR, base | 1, PCI_SIZE_32);
+
+ /*
+ * The PCIEXBAR is assumed to live in the memory mapped IO space under
+ * 4GiB
+ */
+ pci_x86_write_config(plat->bdf, PCIEXBAR + 4, 0, PCI_SIZE_32);
+
+ switch (plat->pciex_region_size >> 20) {
+ default:
+ case 256:
+ region_size = PCIEXBAR_LENGTH_256MB;
+ break;
+ case 128:
+ region_size = PCIEXBAR_LENGTH_128MB;
+ break;
+ case 64:
+ region_size = PCIEXBAR_LENGTH_64MB;
+ break;
+ }
+
+ reg = CONFIG_MMCONF_BASE_ADDRESS | (region_size << 1)
+ | PCIEXBAR_PCIEXBAREN;
+ pci_x86_write_config(plat->bdf, PCIEXBAR, reg, PCI_SIZE_32);
+
+ /*
+ * TSEG defines the base of SMM range. BIOS determines the base
+ * of TSEG memory which must be at or below Graphics base of GTT
+ * Stolen memory, hence its better to clear TSEG register early
+ * to avoid power on default non-zero value (if any).
+ */
+ pci_x86_write_config(plat->bdf, TSEG, 0, PCI_SIZE_32);
+
+ ret = apl_hostbridge_early_init_pinctrl(dev);
+ if (ret)
+ return log_msg_ret("pinctrl", ret);
+
+ return 0;
+}
+
+static int apl_hostbridge_ofdata_to_platdata(struct udevice *dev)
+{
+ struct apl_hostbridge_platdata *plat = dev_get_platdata(dev);
+ struct udevice *pinctrl;
+ int ret;
+
+ /*
+ * The host bridge holds the early pad data needed to get through TPL.
+ * This is a small amount of data, enough to fit in TPL, so we keep it
+ * separate from the full pad data, stored in the fsp-s subnode. That
+ * subnode is not present in TPL, to save space.
+ */
+ ret = uclass_first_device_err(UCLASS_PINCTRL, &pinctrl);
+ if (ret)
+ return log_msg_ret("no hostbridge PINCTRL", ret);
+#if !CONFIG_IS_ENABLED(OF_PLATDATA)
+ int root;
+
+ /* Get length of PCI Express Region */
+ plat->pciex_region_size = dev_read_u32_default(dev, "pciex-region-size",
+ 256 << 20);
+
+ root = pci_get_devfn(dev);
+ if (root < 0)
+ return log_msg_ret("Cannot get host-bridge PCI address", root);
+ plat->bdf = root;
+
+ ret = pinctrl_read_pads(pinctrl, dev_ofnode(dev), "early-pads",
+ &plat->early_pads, &plat->early_pads_count);
+ if (ret)
+ return log_msg_ret("early-pads", ret);
+#else
+ struct dtd_intel_apl_hostbridge *dtplat = &plat->dtplat;
+ int size;
+
+ plat->pciex_region_size = dtplat->pciex_region_size;
+ plat->bdf = pci_ofplat_get_devfn(dtplat->reg[0]);
+
+ /* Assume that if everything is 0, it is empty */
+ plat->early_pads = dtplat->early_pads;
+ size = ARRAY_SIZE(dtplat->early_pads);
+ plat->early_pads_count = pinctrl_count_pads(pinctrl, plat->early_pads,
+ size);
+
+#endif
+
+ return 0;
+}
+
+static int apl_hostbridge_probe(struct udevice *dev)
+{
+ if (spl_phase() == PHASE_TPL)
+ return apl_hostbridge_early_init(dev);
+
+ return 0;
+}
+
+static const struct udevice_id apl_hostbridge_ids[] = {
+ { .compatible = "intel,apl-hostbridge" },
+ { }
+};
+
+U_BOOT_DRIVER(apl_hostbridge_drv) = {
+ .name = "intel_apl_hostbridge",
+ .id = UCLASS_NORTHBRIDGE,
+ .of_match = apl_hostbridge_ids,
+ .ofdata_to_platdata = apl_hostbridge_ofdata_to_platdata,
+ .probe = apl_hostbridge_probe,
+ .platdata_auto_alloc_size = sizeof(struct apl_hostbridge_platdata),
+};
--
2.24.0.393.g34dc348eaf-goog
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