1 files changed, 121 insertions, 0 deletions
diff --git a/drivers/clk/x86/clk-fch.c b/drivers/clk/x86/clk-fch.c
new file mode 100644
index 000000000..fdc060e75
--- /dev/null
+++ b/drivers/clk/x86/clk-fch.c
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: MIT
+/*
+ * clock framework for AMD FCH controller block
+ *
+ * Copyright 2018 Advanced Micro Devices, Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/pci.h>
+#include <linux/platform_data/clk-fch.h>
+#include <linux/platform_device.h>
+
+/* Clock Driving Strength 2 register */
+#define CLKDRVSTR2	0x28
+/* Clock Control 1 register */
+#define MISCCLKCNTL1	0x40
+/* Auxiliary clock1 enable bit */
+#define OSCCLKENB	2
+/* 25Mhz auxiliary output clock freq bit */
+#define OSCOUT1CLK25MHZ	16
+
+#define ST_CLK_48M	0
+#define ST_CLK_25M	1
+#define ST_CLK_MUX	2
+#define ST_CLK_GATE	3
+#define ST_MAX_CLKS	4
+
+#define CLK_48M_FIXED	0
+#define CLK_GATE_FIXED	1
+#define CLK_MAX_FIXED	2
+
+/* List of supported CPU ids for clk mux with 25Mhz clk support */
+#define AMD_CPU_ID_ST                  0x1576
+
+static const char * const clk_oscout1_parents[] = { "clk48MHz", "clk25MHz" };
+static struct clk_hw *hws[ST_MAX_CLKS];
+
+static const struct pci_device_id fch_pci_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, AMD_CPU_ID_ST) },
+	{ }
+};
+
+static int fch_clk_probe(struct platform_device *pdev)
+{
+	struct fch_clk_data *fch_data;
+	struct pci_dev *rdev;
+
+	fch_data = dev_get_platdata(&pdev->dev);
+	if (!fch_data || !fch_data->base)
+		return -EINVAL;
+
+	rdev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
+	if (!rdev) {
+		dev_err(&pdev->dev, "FCH device not found\n");
+		return -ENODEV;
+	}
+
+	if (pci_match_id(fch_pci_ids, rdev)) {
+		hws[ST_CLK_48M] = clk_hw_register_fixed_rate(NULL, "clk48MHz",
+			NULL, 0, 48000000);
+		hws[ST_CLK_25M] = clk_hw_register_fixed_rate(NULL, "clk25MHz",
+			NULL, 0, 25000000);
+
+		hws[ST_CLK_MUX] = clk_hw_register_mux(NULL, "oscout1_mux",
+			clk_oscout1_parents, ARRAY_SIZE(clk_oscout1_parents),
+			0, fch_data->base + CLKDRVSTR2, OSCOUT1CLK25MHZ, 3, 0,
+			NULL);
+
+		clk_set_parent(hws[ST_CLK_MUX]->clk, hws[ST_CLK_48M]->clk);
+
+		hws[ST_CLK_GATE] = clk_hw_register_gate(NULL, "oscout1",
+			"oscout1_mux", 0, fch_data->base + MISCCLKCNTL1,
+			OSCCLKENB, CLK_GATE_SET_TO_DISABLE, NULL);
+
+		devm_clk_hw_register_clkdev(&pdev->dev, hws[ST_CLK_GATE],
+					    fch_data->name, NULL);
+	} else {
+		hws[CLK_48M_FIXED] = clk_hw_register_fixed_rate(NULL, "clk48MHz",
+			NULL, 0, 48000000);
+
+		hws[CLK_GATE_FIXED] = clk_hw_register_gate(NULL, "oscout1",
+			"clk48MHz", 0, fch_data->base + MISCCLKCNTL1,
+			OSCCLKENB, 0, NULL);
+
+		devm_clk_hw_register_clkdev(&pdev->dev, hws[CLK_GATE_FIXED],
+					    fch_data->name, NULL);
+	}
+
+	pci_dev_put(rdev);
+	return 0;
+}
+
+static int fch_clk_remove(struct platform_device *pdev)
+{
+	int i, clks;
+	struct pci_dev *rdev;
+
+	rdev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
+	if (!rdev)
+		return -ENODEV;
+
+	clks = pci_match_id(fch_pci_ids, rdev) ? CLK_MAX_FIXED : ST_MAX_CLKS;
+
+	for (i = 0; i < clks; i++)
+		clk_hw_unregister(hws[i]);
+
+	pci_dev_put(rdev);
+	return 0;
+}
+
+static struct platform_driver fch_clk_driver = {
+	.driver = {
+		.name = "clk-fch",
+		.suppress_bind_attrs = true,
+	},
+	.probe = fch_clk_probe,
+	.remove = fch_clk_remove,
+};
+builtin_platform_driver(fch_clk_driver);