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>

1 files changed, 146 insertions, 0 deletions

diff --git a/drivers/clk/socfpga/clk-pll-s10.c b/drivers/clk/socfpga/clk-pll-s10.c
new file mode 100644
index 000000000000..2d5d8b43727e
--- /dev/null
+++ b/drivers/clk/socfpga/clk-pll-s10.c
@@ -0,0 +1,146 @@
+// 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"
+
+/* Clock Manager offsets */
+#define CLK_MGR_PLL_CLK_SRC_SHIFT	16
+#define CLK_MGR_PLL_CLK_SRC_MASK	0x3
+
+/* PLL Clock enable bits */
+#define SOCFPGA_PLL_POWER		0
+#define SOCFPGA_PLL_RESET_MASK		0x2
+#define SOCFPGA_PLL_REFDIV_MASK		0x00003F00
+#define SOCFPGA_PLL_REFDIV_SHIFT	8
+#define SOCFPGA_PLL_MDIV_MASK		0xFF000000
+#define SOCFPGA_PLL_MDIV_SHIFT		24
+#define SWCTRLBTCLKSEL_MASK		0x200
+#define SWCTRLBTCLKSEL_SHIFT		9
+
+#define SOCFPGA_BOOT_CLK		"boot_clk"
+
+#define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw)
+
+static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
+					 unsigned long parent_rate)
+{
+	struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
+	unsigned long mdiv;
+	unsigned long refdiv;
+	unsigned long reg;
+	unsigned long long vco_freq;
+
+	/* read VCO1 reg for numerator and denominator */
+	reg = readl(socfpgaclk->hw.reg);
+	refdiv = (reg & SOCFPGA_PLL_REFDIV_MASK) >> SOCFPGA_PLL_REFDIV_SHIFT;
+	vco_freq = (unsigned long long)parent_rate / refdiv;
+
+	/* Read mdiv and fdiv from the fdbck register */
+	reg = readl(socfpgaclk->hw.reg + 0x4);
+	mdiv = (reg & SOCFPGA_PLL_MDIV_MASK) >> SOCFPGA_PLL_MDIV_SHIFT;
+	vco_freq = (unsigned long long)parent_rate * (mdiv + 6);
+
+	return (unsigned long)vco_freq;
+}
+
+static unsigned long clk_boot_clk_recalc_rate(struct clk_hw *hwclk,
+					 unsigned long parent_rate)
+{
+	struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
+	u32 div = 1;
+
+	div = ((readl(socfpgaclk->hw.reg) &
+		SWCTRLBTCLKSEL_MASK) >>
+		SWCTRLBTCLKSEL_SHIFT);
+	div += 1;
+	return parent_rate /= div;
+}
+
+
+static u8 clk_pll_get_parent(struct clk_hw *hwclk)
+{
+	struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
+	u32 pll_src;
+
+	pll_src = readl(socfpgaclk->hw.reg);
+	return (pll_src >> CLK_MGR_PLL_CLK_SRC_SHIFT) &
+		CLK_MGR_PLL_CLK_SRC_MASK;
+}
+
+static u8 clk_boot_get_parent(struct clk_hw *hwclk)
+{
+	struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
+	u32 pll_src;
+
+	pll_src = readl(socfpgaclk->hw.reg);
+	return (pll_src >> SWCTRLBTCLKSEL_SHIFT) &
+		SWCTRLBTCLKSEL_MASK;
+}
+
+static int clk_pll_prepare(struct clk_hw *hwclk)
+{
+	struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
+	u32 reg;
+
+	/* Bring PLL out of reset */
+	reg = readl(socfpgaclk->hw.reg);
+	reg |= SOCFPGA_PLL_RESET_MASK;
+	writel(reg, socfpgaclk->hw.reg);
+
+	return 0;
+}
+
+static struct clk_ops clk_pll_ops = {
+	.recalc_rate = clk_pll_recalc_rate,
+	.get_parent = clk_pll_get_parent,
+	.prepare = clk_pll_prepare,
+};
+
+static struct clk_ops clk_boot_ops = {
+	.recalc_rate = clk_boot_clk_recalc_rate,
+	.get_parent = clk_boot_get_parent,
+	.prepare = clk_pll_prepare,
+};
+
+struct clk *s10_register_pll(const char *name, const char * const *parent_names,
+				    u8 num_parents, unsigned long flags,
+				    void __iomem *reg, unsigned long offset)
+{
+	struct clk *clk;
+	struct socfpga_pll *pll_clk;
+	struct clk_init_data init;
+
+	pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
+	if (WARN_ON(!pll_clk))
+		return NULL;
+
+	pll_clk->hw.reg = reg + offset;
+
+	if (streq(name, SOCFPGA_BOOT_CLK))
+		init.ops = &clk_boot_ops;
+	else
+		init.ops = &clk_pll_ops;
+
+	init.name = name;
+	init.flags = flags;
+
+	init.num_parents = num_parents;
+	init.parent_names = parent_names;
+	pll_clk->hw.hw.init = &init;
+
+	pll_clk->hw.bit_idx = SOCFPGA_PLL_POWER;
+	clk_pll_ops.enable = clk_gate_ops.enable;
+	clk_pll_ops.disable = clk_gate_ops.disable;
+
+	clk = clk_register(NULL, &pll_clk->hw.hw);
+	if (WARN_ON(IS_ERR(clk))) {
+		kfree(pll_clk);
+		return NULL;
+	}
+	return clk;
+}