x86: apl: Add P2SB driver

Adds a driver for the Apollo Lake Primary-to-sideband bus. This supports
various child devices. It supposed both device tree and of-platdata.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

2 files changed, 167 insertions, 0 deletions

diff --git a/arch/x86/cpu/apollolake/Makefile b/arch/x86/cpu/apollolake/Makefile
index edde122f75..dc6df15dab 100644
--- a/arch/x86/cpu/apollolake/Makefile
+++ b/arch/x86/cpu/apollolake/Makefile
@@ -15,6 +15,7 @@ endif
 obj-y += hostbridge.o
 obj-y += itss.o
 obj-y += lpc.o
+obj-y += p2sb.o
 obj-y += pch.o
 obj-y += pmc.o
 obj-y += uart.o
diff --git a/arch/x86/cpu/apollolake/p2sb.c b/arch/x86/cpu/apollolake/p2sb.c
new file mode 100644
index 0000000000..eb27861b7a
--- /dev/null
+++ b/arch/x86/cpu/apollolake/p2sb.c
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Primary-to-Sideband Bridge
+ *
+ * Copyright 2019 Google LLC
+ */
+
+#define LOG_CATEGORY UCLASS_P2SB
+
+#include <common.h>
+#include <dm.h>
+#include <dt-structs.h>
+#include <p2sb.h>
+#include <spl.h>
+#include <asm/pci.h>
+
+struct p2sb_platdata {
+#if CONFIG_IS_ENABLED(OF_PLATDATA)
+	struct dtd_intel_apl_p2sb dtplat;
+#endif
+	ulong mmio_base;
+	pci_dev_t bdf;
+};
+
+/* PCI config space registers */
+#define HPTC_OFFSET		0x60
+#define HPTC_ADDR_ENABLE_BIT	BIT(7)
+
+/* High Performance Event Timer Configuration */
+#define P2SB_HPTC				0x60
+#define P2SB_HPTC_ADDRESS_ENABLE		BIT(7)
+
+/*
+ * ADDRESS_SELECT            ENCODING_RANGE
+ *      0                 0xfed0 0000 - 0xfed0 03ff
+ *      1                 0xfed0 1000 - 0xfed0 13ff
+ *      2                 0xfed0 2000 - 0xfed0 23ff
+ *      3                 0xfed0 3000 - 0xfed0 33ff
+ */
+#define P2SB_HPTC_ADDRESS_SELECT_0		(0 << 0)
+#define P2SB_HPTC_ADDRESS_SELECT_1		(1 << 0)
+#define P2SB_HPTC_ADDRESS_SELECT_2		(2 << 0)
+#define P2SB_HPTC_ADDRESS_SELECT_3		(3 << 0)
+
+/*
+ * apl_p2sb_early_init() - Enable decoding for HPET range
+ *
+ * This is needed by FSP-M which uses the High Precision Event Timer.
+ *
+ * @dev: P2SB device
+ * @return 0 if OK, -ve on error
+ */
+static int apl_p2sb_early_init(struct udevice *dev)
+{
+	struct p2sb_platdata *plat = dev_get_platdata(dev);
+	pci_dev_t pdev = plat->bdf;
+
+	/*
+	 * Enable decoding for HPET memory address range.
+	 * HPTC_OFFSET(0x60) bit 7, when set the P2SB will decode
+	 * the High Performance Timer memory address range
+	 * selected by bits 1:0
+	 */
+	pci_x86_write_config(pdev, HPTC_OFFSET, HPTC_ADDR_ENABLE_BIT,
+			     PCI_SIZE_8);
+
+	/* Enable PCR Base address in PCH */
+	pci_x86_write_config(pdev, PCI_BASE_ADDRESS_0, plat->mmio_base,
+			     PCI_SIZE_32);
+	pci_x86_write_config(pdev, PCI_BASE_ADDRESS_1, 0, PCI_SIZE_32);
+
+	/* Enable P2SB MSE */
+	pci_x86_write_config(pdev, PCI_COMMAND, PCI_COMMAND_MASTER |
+			     PCI_COMMAND_MEMORY, PCI_SIZE_8);
+
+	return 0;
+}
+
+static int apl_p2sb_spl_init(struct udevice *dev)
+{
+	/* Enable decoding for HPET. Needed for FSP global pointer storage */
+	dm_pci_write_config(dev, P2SB_HPTC, P2SB_HPTC_ADDRESS_SELECT_0 |
+			    P2SB_HPTC_ADDRESS_ENABLE, PCI_SIZE_8);
+
+	return 0;
+}
+
+int apl_p2sb_ofdata_to_platdata(struct udevice *dev)
+{
+	struct p2sb_uc_priv *upriv = dev_get_uclass_priv(dev);
+	struct p2sb_platdata *plat = dev_get_platdata(dev);
+
+#if !CONFIG_IS_ENABLED(OF_PLATDATA)
+	int ret;
+
+	if (spl_phase() == PHASE_TPL) {
+		u32 base[2];
+
+		/* TPL sets up the initial BAR */
+		ret = dev_read_u32_array(dev, "early-regs", base,
+					 ARRAY_SIZE(base));
+		if (ret)
+			return log_msg_ret("Missing/short early-regs", ret);
+		plat->mmio_base = base[0];
+		plat->bdf = pci_get_devfn(dev);
+		if (plat->bdf < 0)
+			return log_msg_ret("Cannot get p2sb PCI address",
+					   plat->bdf);
+	} else {
+		plat->mmio_base = dev_read_addr_pci(dev);
+		/* Don't set BDF since it should not be used */
+		if (!plat->mmio_base || plat->mmio_base == FDT_ADDR_T_NONE)
+			return -EINVAL;
+	}
+#else
+	plat->mmio_base = plat->dtplat.early_regs[0];
+	plat->bdf = pci_ofplat_get_devfn(plat->dtplat.reg[0]);
+#endif
+	upriv->mmio_base = plat->mmio_base;
+	debug("p2sb: mmio_base=%x\n", (uint)plat->mmio_base);
+
+	return 0;
+}
+
+static int apl_p2sb_probe(struct udevice *dev)
+{
+	if (spl_phase() == PHASE_TPL)
+		return apl_p2sb_early_init(dev);
+	else if (spl_phase() == PHASE_SPL)
+		return apl_p2sb_spl_init(dev);
+
+	return 0;
+}
+
+static int p2sb_child_post_bind(struct udevice *dev)
+{
+#if !CONFIG_IS_ENABLED(OF_PLATDATA)
+	struct p2sb_child_platdata *pplat = dev_get_parent_platdata(dev);
+	int ret;
+	u32 pid;
+
+	ret = dev_read_u32(dev, "intel,p2sb-port-id", &pid);
+	if (ret)
+		return ret;
+	pplat->pid = pid;
+#endif
+
+	return 0;
+}
+
+static const struct udevice_id apl_p2sb_ids[] = {
+	{ .compatible = "intel,apl-p2sb" },
+	{ }
+};
+
+U_BOOT_DRIVER(apl_p2sb_drv) = {
+	.name		= "intel_apl_p2sb",
+	.id		= UCLASS_P2SB,
+	.of_match	= apl_p2sb_ids,
+	.probe		= apl_p2sb_probe,
+	.ofdata_to_platdata = apl_p2sb_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct p2sb_platdata),
+	.per_child_platdata_auto_alloc_size =
+		sizeof(struct p2sb_child_platdata),
+	.child_post_bind = p2sb_child_post_bind,
+};