clk: socfpga: stratix10: add clock driver for Stratix10 platform

Add a clock driver for the Stratix10 SoC. The driver is similar to the
Cyclone5/Arria10 platforms, with the exception that this driver only uses
one single clock binding.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/socfpga/clk-periph-s10.c

@@ -0,0 +1,149 @@
+// SPDX-License-Identifier:	GPL-2.0
+/*
+ * Copyright (C) 2017, Intel Corporation
+ */
+#include <linux/slab.h>
+#include <linux/clk-provider.h>
+
+#include "stratix10-clk.h"
+#include "clk.h"
+
+#define CLK_MGR_FREE_SHIFT		16
+#define CLK_MGR_FREE_MASK		0x7
+#define SWCTRLBTCLKSEN_SHIFT		8
+
+#define to_periph_clk(p) container_of(p, struct socfpga_periph_clk, hw.hw)
+
+static unsigned long clk_peri_c_clk_recalc_rate(struct clk_hw *hwclk,
+					     unsigned long parent_rate)
+{
+	struct socfpga_periph_clk *socfpgaclk = to_periph_clk(hwclk);
+	unsigned long div = 1;
+	u32 val;
+
+	val = readl(socfpgaclk->hw.reg);
+	val &= GENMASK(SWCTRLBTCLKSEN_SHIFT - 1, 0);
+	parent_rate /= val;
+
+	return parent_rate / div;
+}
+
+static unsigned long clk_peri_cnt_clk_recalc_rate(struct clk_hw *hwclk,
+					     unsigned long parent_rate)
+{
+	struct socfpga_periph_clk *socfpgaclk = to_periph_clk(hwclk);
+	unsigned long div = 1;
+
+	if (socfpgaclk->fixed_div) {
+		div = socfpgaclk->fixed_div;
+	} else {
+		if (!socfpgaclk->bypass_reg)
+			div = ((readl(socfpgaclk->hw.reg) & 0x7ff) + 1);
+	}
+
+	return parent_rate / div;
+}
+
+static u8 clk_periclk_get_parent(struct clk_hw *hwclk)
+{
+	struct socfpga_periph_clk *socfpgaclk = to_periph_clk(hwclk);
+	u32 clk_src, mask;
+	u8 parent;
+
+	if (socfpgaclk->bypass_reg) {
+		mask = (0x1 << socfpgaclk->bypass_shift);
+		parent = ((readl(socfpgaclk->bypass_reg) & mask) >>
+			   socfpgaclk->bypass_shift);
+	} else {
+		clk_src = readl(socfpgaclk->hw.reg);
+		parent = (clk_src >> CLK_MGR_FREE_SHIFT) &
+			CLK_MGR_FREE_MASK;
+	}
+	return parent;
+}
+
+static const struct clk_ops peri_c_clk_ops = {
+	.recalc_rate = clk_peri_c_clk_recalc_rate,
+	.get_parent = clk_periclk_get_parent,
+};
+
+static const struct clk_ops peri_cnt_clk_ops = {
+	.recalc_rate = clk_peri_cnt_clk_recalc_rate,
+	.get_parent = clk_periclk_get_parent,
+};
+
+struct clk *s10_register_periph(const char *name, const char *parent_name,
+				const char * const *parent_names,
+				u8 num_parents, unsigned long flags,
+				void __iomem *reg, unsigned long offset)
+{
+	struct clk *clk;
+	struct socfpga_periph_clk *periph_clk;
+	struct clk_init_data init;
+
+	periph_clk = kzalloc(sizeof(*periph_clk), GFP_KERNEL);
+	if (WARN_ON(!periph_clk))
+		return NULL;
+
+	periph_clk->hw.reg = reg + offset;
+
+	init.name = name;
+	init.ops = &peri_c_clk_ops;
+	init.flags = flags;
+
+	init.num_parents = num_parents;
+	init.parent_names = parent_names ? parent_names : &parent_name;
+
+	periph_clk->hw.hw.init = &init;
+
+	clk = clk_register(NULL, &periph_clk->hw.hw);
+	if (WARN_ON(IS_ERR(clk))) {
+		kfree(periph_clk);
+		return NULL;
+	}
+	return clk;
+}
+
+struct clk *s10_register_cnt_periph(const char *name, const char *parent_name,
+				    const char * const *parent_names,
+				    u8 num_parents, unsigned long flags,
+				    void __iomem *regbase, unsigned long offset,
+				    u8 fixed_divider, unsigned long bypass_reg,
+				    unsigned long bypass_shift)
+{
+	struct clk *clk;
+	struct socfpga_periph_clk *periph_clk;
+	struct clk_init_data init;
+
+	periph_clk = kzalloc(sizeof(*periph_clk), GFP_KERNEL);
+	if (WARN_ON(!periph_clk))
+		return NULL;
+
+	if (offset)
+		periph_clk->hw.reg = regbase + offset;
+	else
+		periph_clk->hw.reg = NULL;
+
+	if (bypass_reg)
+		periph_clk->bypass_reg = regbase + bypass_reg;
+	else
+		periph_clk->bypass_reg = NULL;
+	periph_clk->bypass_shift = bypass_shift;
+	periph_clk->fixed_div = fixed_divider;
+
+	init.name = name;
+	init.ops = &peri_cnt_clk_ops;
+	init.flags = flags;
+
+	init.num_parents = num_parents;
+	init.parent_names = parent_names ? parent_names : &parent_name;
+
+	periph_clk->hw.hw.init = &init;
+
+	clk = clk_register(NULL, &periph_clk->hw.hw);
+	if (WARN_ON(IS_ERR(clk))) {
+		kfree(periph_clk);
+		return NULL;
+	}
+	return clk;
+}