1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/clk/imgtec/clk-boston.c b/drivers/clk/imgtec/clk-boston.c
new file mode 100644
index 000000000000..f18f10351785
--- /dev/null
+++ b/drivers/clk/imgtec/clk-boston.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2016-2017 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#define pr_fmt(fmt) "clk-boston: " fmt
+
+#include <linux/clk-provider.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+
+#include <dt-bindings/clock/boston-clock.h>
+
+#define BOSTON_PLAT_MMCMDIV		0x30
+# define BOSTON_PLAT_MMCMDIV_CLK0DIV	(0xff << 0)
+# define BOSTON_PLAT_MMCMDIV_INPUT	(0xff << 8)
+# define BOSTON_PLAT_MMCMDIV_MUL	(0xff << 16)
+# define BOSTON_PLAT_MMCMDIV_CLK1DIV	(0xff << 24)
+
+#define BOSTON_CLK_COUNT 3
+
+static u32 ext_field(u32 val, u32 mask)
+{
+	return (val & mask) >> (ffs(mask) - 1);
+}
+
+static void __init clk_boston_setup(struct device_node *np)
+{
+	unsigned long in_freq, cpu_freq, sys_freq;
+	uint mmcmdiv, mul, cpu_div, sys_div;
+	struct clk_hw_onecell_data *onecell;
+	struct regmap *regmap;
+	struct clk_hw *hw;
+	int err;
+
+	regmap = syscon_node_to_regmap(np->parent);
+	if (IS_ERR(regmap)) {
+		pr_err("failed to find regmap\n");
+		return;
+	}
+
+	err = regmap_read(regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv);
+	if (err) {
+		pr_err("failed to read mmcm_div register: %d\n", err);
+		return;
+	}
+
+	in_freq = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT) * 1000000;
+	mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL);
+
+	sys_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV);
+	sys_freq = mult_frac(in_freq, mul, sys_div);
+
+	cpu_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV);
+	cpu_freq = mult_frac(in_freq, mul, cpu_div);
+
+	onecell = kzalloc(sizeof(*onecell) +
+			  (BOSTON_CLK_COUNT * sizeof(struct clk_hw *)),
+			  GFP_KERNEL);
+	if (!onecell)
+		return;
+
+	onecell->num = BOSTON_CLK_COUNT;
+
+	hw = clk_hw_register_fixed_rate(NULL, "input", NULL, 0, in_freq);
+	if (IS_ERR(hw)) {
+		pr_err("failed to register input clock: %ld\n", PTR_ERR(hw));
+		return;
+	}
+	onecell->hws[BOSTON_CLK_INPUT] = hw;
+
+	hw = clk_hw_register_fixed_rate(NULL, "sys", "input", 0, sys_freq);
+	if (IS_ERR(hw)) {
+		pr_err("failed to register sys clock: %ld\n", PTR_ERR(hw));
+		return;
+	}
+	onecell->hws[BOSTON_CLK_SYS] = hw;
+
+	hw = clk_hw_register_fixed_rate(NULL, "cpu", "input", 0, cpu_freq);
+	if (IS_ERR(hw)) {
+		pr_err("failed to register cpu clock: %ld\n", PTR_ERR(hw));
+		return;
+	}
+	onecell->hws[BOSTON_CLK_CPU] = hw;
+
+	err = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, onecell);
+	if (err)
+		pr_err("failed to add DT provider: %d\n", err);
+}
+
+/*
+ * Use CLK_OF_DECLARE so that this driver is probed early enough to provide the
+ * CPU frequency for use with the GIC or cop0 counters/timers.
+ */
+CLK_OF_DECLARE(clk_boston, "img,boston-clock", clk_boston_setup);