[PATCH] clk: Add clock driver for AXM55xx SoC

[Anders Berg]

From: Anders Berg <anders.berg@xxxxxxx>

Add clk driver to support clock blocks found on the AXM55xx devices. The driver
provides clock implementations for three different types of clock devices on
the AXM55xx device: PLL clock, a clock divider and a clock mux.

Signed-off-by: Anders Berg <anders.berg@xxxxxxx>
Cc: Mike Turquette <mturquette@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
---
 .../devicetree/bindings/clock/lsi,axm5516-clks.txt |  29 +
 drivers/clk/Makefile                               |   1 +
 drivers/clk/clk-axm5516.c                          | 615 +++++++++++++++++++++
 3 files changed, 645 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/lsi,axm5516-clks.txt
 create mode 100644 drivers/clk/clk-axm5516.c

diff --git a/Documentation/devicetree/bindings/clock/lsi,axm5516-clks.txt b/Documentation/devicetree/bindings/clock/lsi,axm5516-clks.txt
new file mode 100644
index 0000000..3ce97cf
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/lsi,axm5516-clks.txt
@@ -0,0 +1,29 @@
+AXM5516 clock driver bindings
+-----------------------------
+
+Required properties :
+- compatible : shall contain "lsi,axm5516-clks"
+- reg : shall contain base register location and length
+- #clock-cells : shall contain 1
+
+The consumer specifies the desired clock by having the clock ID in its "clocks"
+phandle cell. See <dt-bindings/clock/lsi,axxia-clock.h> for the list of
+supported clock IDs.
+
+Example:
+
+	clks: clock-controller@2010020000 {
+		compatible = "lsi,axm5516-clks";
+		#clock-cells = <1>;
+		reg = <0x20 0x10020000 0 0x20000>;
+	};
+
+	serial0: uart@2010080000 {
+		compatible = "arm,pl011", "arm,primecell";
+		reg = <0x20 0x10080000 0 0x1000>;
+		interrupts = <GIC_SPI 56 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&clks AXXIA_CLK_PER>;
+		clock-names = "apb_pclk";
+	};
+																																};
+
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 5f8a287..32051e7 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_COMMON_CLK)	+= clk-composite.o
 # hardware specific clock types
 # please keep this section sorted lexicographically by file/directory path name
 obj-$(CONFIG_COMMON_CLK_AXI_CLKGEN)	+= clk-axi-clkgen.o
+obj-$(CONFIG_ARCH_AXXIA)		+= clk-axm5516.o
 obj-$(CONFIG_ARCH_BCM2835)		+= clk-bcm2835.o
 obj-$(CONFIG_ARCH_EFM32)		+= clk-efm32gg.o
 obj-$(CONFIG_ARCH_HIGHBANK)		+= clk-highbank.o
diff --git a/drivers/clk/clk-axm5516.c b/drivers/clk/clk-axm5516.c
new file mode 100644
index 0000000..d2f1e11
--- /dev/null
+++ b/drivers/clk/clk-axm5516.c
@@ -0,0 +1,615 @@
+/*
+ * drivers/clk/clk-axm5516.c
+ *
+ * Provides clock implementations for three different types of clock devices on
+ * the Axxia device: PLL clock, a clock divider and a clock mux.
+ *
+ * Copyright (C) 2014 LSI Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+#include <dt-bindings/clock/lsi,axm5516-clks.h>
+
+
+/**
+ * struct axxia_clk - Common struct to all Axxia clocks.
+ * @hw: clk_hw for the common clk framework
+ * @regmap: Regmap for the clock control registers
+ */
+struct axxia_clk {
+	struct clk_hw hw;
+	struct regmap *regmap;
+};
+#define to_axxia_clk(_hw) container_of(_hw, struct axxia_clk, hw)
+
+/**
+ * struct axxia_pllclk - Axxia PLL generated clock.
+ * @aclk: Common struct
+ * @reg: Offset into regmap for PLL control register
+ */
+struct axxia_pllclk {
+	struct axxia_clk aclk;
+	u32 reg;
+};
+#define to_axxia_pllclk(_aclk) container_of(_aclk, struct axxia_pllclk, aclk)
+
+/**
+ * axxia_pllclk_recalc - Calculate the PLL generated clock rate given the
+ * parent clock rate.
+ */
+static unsigned long
+axxia_pllclk_recalc(struct clk_hw *hw, unsigned long parent_rate)
+{
+	struct axxia_clk *aclk = to_axxia_clk(hw);
+	struct axxia_pllclk *pll = to_axxia_pllclk(aclk);
+	unsigned long rate, fbdiv, refdiv, postdiv;
+	u32 control;
+
+	regmap_read(aclk->regmap, pll->reg, &control);
+	postdiv = ((control >> 0) & 0xf) + 1;
+	fbdiv   = ((control >> 4) & 0xfff) + 3;
+	refdiv  = ((control >> 16) & 0x1f) + 1;
+	rate = (parent_rate / (refdiv * postdiv)) * fbdiv;
+
+	return rate;
+}
+
+static const struct clk_ops axxia_pllclk_ops = {
+	.recalc_rate = axxia_pllclk_recalc,
+};
+
+/**
+ * struct axxia_divclk - Axxia clock divider
+ * @aclk: Common struct
+ * @reg: Offset into regmap for PLL control register
+ * @shift: Bit position for divider value
+ * @width: Number of bits in divider value
+ */
+struct axxia_divclk {
+	struct axxia_clk aclk;
+	u32 reg;
+	u32 shift;
+	u32 width;
+};
+#define to_axxia_divclk(_aclk) container_of(_aclk, struct axxia_divclk, aclk)
+
+/**
+ * axxia_divclk_recalc_rate - Calculate clock divider output rage
+ */
+static unsigned long
+axxia_divclk_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+	struct axxia_clk *aclk = to_axxia_clk(hw);
+	struct axxia_divclk *divclk = to_axxia_divclk(aclk);
+	u32 ctrl, div;
+
+	regmap_read(aclk->regmap, divclk->reg, &ctrl);
+	div = 1 + ((ctrl >> divclk->shift) & ((1 << divclk->width)-1));
+
+	return parent_rate / div;
+}
+
+static const struct clk_ops axxia_divclk_ops = {
+	.recalc_rate = axxia_divclk_recalc_rate,
+};
+
+/**
+ * struct axxia_clkmux - Axxia clock mux
+ * @aclk: Common struct
+ * @reg: Offset into regmap for PLL control register
+ * @shift: Bit position for selection value
+ * @width: Number of bits in selection value
+ */
+struct axxia_clkmux {
+	struct axxia_clk aclk;
+	u32 reg;
+	u32 shift;
+	u32 width;
+};
+#define to_axxia_clkmux(_aclk) container_of(_aclk, struct axxia_clkmux, aclk)
+
+/**
+ * axxia_clkmux_get_parent - Return the index of selected parent clock
+ */
+static u8 axxia_clkmux_get_parent(struct clk_hw *hw)
+{
+	struct axxia_clk *aclk = to_axxia_clk(hw);
+	struct axxia_clkmux *mux = to_axxia_clkmux(aclk);
+	u32 ctrl, parent;
+
+	regmap_read(aclk->regmap, mux->reg, &ctrl);
+	parent = (ctrl >> mux->shift) & ((1 << mux->width) - 1);
+
+	return (u8) parent;
+}
+
+static const struct clk_ops axxia_clkmux_ops = {
+	.get_parent = axxia_clkmux_get_parent,
+};
+
+
+/*
+ * PLLs
+ */
+
+static struct axxia_pllclk clk_fab_pll = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_fab_pll",
+		.parent_names = (const char *[]){
+			"clk_ref0"
+		},
+		.num_parents = 1,
+		.ops = &axxia_pllclk_ops,
+	},
+	.reg   = 0x01800,
+};
+
+static struct axxia_pllclk clk_cpu_pll = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_cpu_pll",
+		.parent_names = (const char *[]){
+			"clk_ref0"
+		},
+		.num_parents = 1,
+		.ops = &axxia_pllclk_ops,
+	},
+	.reg   = 0x02000,
+};
+
+static struct axxia_pllclk clk_sys_pll = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_sys_pll",
+		.parent_names = (const char *[]){
+			"clk_ref0"
+		},
+		.num_parents = 1,
+		.ops = &axxia_pllclk_ops,
+	},
+	.reg   = 0x02800,
+};
+
+static struct axxia_pllclk clk_sm0_pll = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_sm0_pll",
+		.parent_names = (const char *[]){
+			"clk_ref2"
+		},
+		.num_parents = 1,
+		.ops = &axxia_pllclk_ops,
+	},
+	.reg   = 0x03000,
+};
+
+static struct axxia_pllclk clk_sm1_pll = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_sm1_pll",
+		.parent_names = (const char *[]){
+			"clk_ref1"
+		},
+		.num_parents = 1,
+		.ops = &axxia_pllclk_ops,
+	},
+	.reg   = 0x03800,
+};
+
+/*
+ * Clock dividers
+ */
+
+static struct axxia_divclk clk_cpu0_div = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_cpu0_div",
+		.parent_names = (const char *[]){
+			"clk_cpu_pll"
+		},
+		.num_parents = 1,
+		.ops = &axxia_divclk_ops,
+	},
+	.reg   = 0x10008,
+	.shift = 0,
+	.width = 4,
+};
+
+static struct axxia_divclk clk_cpu1_div = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_cpu1_div",
+		.parent_names = (const char *[]){
+			"clk_cpu_pll"
+		},
+		.num_parents = 1,
+		.ops = &axxia_divclk_ops,
+	},
+	.reg   = 0x10008,
+	.shift = 4,
+	.width = 4,
+};
+
+static struct axxia_divclk clk_cpu2_div = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_cpu2_div",
+		.parent_names = (const char *[]){
+			"clk_cpu_pll"
+		},
+		.num_parents = 1,
+		.ops = &axxia_divclk_ops,
+	},
+	.reg   = 0x10008,
+	.shift = 8,
+	.width = 4,
+};
+
+static struct axxia_divclk clk_cpu3_div = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_cpu3_div",
+		.parent_names = (const char *[]){
+			"clk_cpu_pll"
+		},
+		.num_parents = 1,
+		.ops = &axxia_divclk_ops,
+	},
+	.reg   = 0x10008,
+	.shift = 12,
+	.width = 4,
+};
+
+static struct axxia_divclk clk_nrcp_div = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_nrcp_div",
+		.parent_names = (const char *[]){
+			"clk_sys_pll"
+		},
+		.num_parents = 1,
+		.ops = &axxia_divclk_ops,
+	},
+	.reg   = 0x1000c,
+	.shift = 0,
+	.width = 4,
+};
+
+static struct axxia_divclk clk_sys_div = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_sys_div",
+		.parent_names = (const char *[]){
+			"clk_sys_pll"
+		},
+		.num_parents = 1,
+		.ops = &axxia_divclk_ops,
+	},
+	.reg   = 0x1000c,
+	.shift = 4,
+	.width = 4,
+};
+
+static struct axxia_divclk clk_fab_div = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_fab_div",
+		.parent_names = (const char *[]){
+			"clk_fab_pll"
+		},
+		.num_parents = 1,
+		.ops = &axxia_divclk_ops,
+	},
+	.reg   = 0x1000c,
+	.shift = 8,
+	.width = 4,
+};
+
+static struct axxia_divclk clk_per_div = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_per_div",
+		.parent_names = (const char *[]){
+			"clk_sm1_pll"
+		},
+		.num_parents = 1,
+		.flags = CLK_IS_BASIC,
+		.ops = &axxia_divclk_ops,
+	},
+	.reg   = 0x1000c,
+	.shift = 12,
+	.width = 4,
+};
+
+static struct axxia_divclk clk_mmc_div = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_mmc_div",
+		.parent_names = (const char *[]){
+			"clk_sm1_pll"
+		},
+		.num_parents = 1,
+		.flags = CLK_IS_BASIC,
+		.ops = &axxia_divclk_ops,
+	},
+	.reg   = 0x1000c,
+	.shift = 16,
+	.width = 4,
+};
+
+/*
+ * Clock MUXes
+ */
+
+static struct axxia_clkmux clk_cpu0_mux = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_cpu0",
+		.parent_names = (const char *[]){
+			"clk_ref0",
+			"clk_cpu_pll",
+			"clk_cpu0_div",
+			"clk_cpu0_div"
+		},
+		.num_parents = 4,
+		.ops = &axxia_clkmux_ops,
+	},
+	.reg   = 0x10000,
+	.shift = 0,
+	.width = 2,
+};
+
+static struct axxia_clkmux clk_cpu1_mux = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_cpu1",
+		.parent_names = (const char *[]){
+			"clk_ref0",
+			"clk_cpu_pll",
+			"clk_cpu1_div",
+			"clk_cpu1_div"
+		},
+		.num_parents = 4,
+		.ops = &axxia_clkmux_ops,
+	},
+	.reg   = 0x10000,
+	.shift = 2,
+	.width = 2,
+};
+
+static struct axxia_clkmux clk_cpu2_mux = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_cpu2",
+		.parent_names = (const char *[]){
+			"clk_ref0",
+			"clk_cpu_pll",
+			"clk_cpu2_div",
+			"clk_cpu2_div"
+		},
+		.num_parents = 4,
+		.ops = &axxia_clkmux_ops,
+	},
+	.reg   = 0x10000,
+	.shift = 4,
+	.width = 2,
+};
+
+static struct axxia_clkmux clk_cpu3_mux = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_cpu3",
+		.parent_names = (const char *[]){
+			"clk_ref0",
+			"clk_cpu_pll",
+			"clk_cpu3_div",
+			"clk_cpu3_div"
+		},
+		.num_parents = 4,
+		.ops = &axxia_clkmux_ops,
+	},
+	.reg   = 0x10000,
+	.shift = 6,
+	.width = 2,
+};
+
+static struct axxia_clkmux clk_nrcp_mux = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_nrcp",
+		.parent_names = (const char *[]){
+			"clk_ref0",
+			"clk_sys_pll",
+			"clk_nrcp_div",
+			"clk_nrcp_div"
+		},
+		.num_parents = 4,
+		.ops = &axxia_clkmux_ops,
+	},
+	.reg   = 0x10004,
+	.shift = 0,
+	.width = 2,
+};
+
+static struct axxia_clkmux clk_sys_mux = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_sys",
+		.parent_names = (const char *[]){
+			"clk_ref0",
+			"clk_sys_pll",
+			"clk_sys_div",
+			"clk_sys_div"
+		},
+		.num_parents = 4,
+		.ops = &axxia_clkmux_ops,
+	},
+	.reg   = 0x10004,
+	.shift = 2,
+	.width = 2,
+};
+
+static struct axxia_clkmux clk_fab_mux = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_fab",
+		.parent_names = (const char *[]){
+			"clk_ref0",
+			"clk_fab_pll",
+			"clk_fab_div",
+			"clk_fab_div"
+		},
+		.num_parents = 4,
+		.ops = &axxia_clkmux_ops,
+	},
+	.reg   = 0x10004,
+	.shift = 4,
+	.width = 2,
+};
+
+static struct axxia_clkmux clk_per_mux = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_per",
+		.parent_names = (const char *[]){
+			"clk_ref1",
+			"clk_per_div"
+		},
+		.num_parents = 2,
+		.ops = &axxia_clkmux_ops,
+	},
+	.reg   = 0x10004,
+	.shift = 6,
+	.width = 1,
+};
+
+static struct axxia_clkmux clk_mmc_mux = {
+	.aclk.hw.init = &(struct clk_init_data){
+		.name = "clk_mmc",
+		.parent_names = (const char *[]){
+			"clk_ref1",
+			"clk_mmc_div"
+		},
+		.num_parents = 2,
+		.ops = &axxia_clkmux_ops,
+	},
+	.reg   = 0x10004,
+	.shift = 9,
+	.width = 1,
+};
+
+/* Table of all supported clocks indexed by the clock identifiers from the
+ * device tree binding
+ */
+static struct axxia_clk *axmclk_clocks[] = {
+	[AXXIA_CLK_FAB_PLL]  = &clk_fab_pll.aclk,
+	[AXXIA_CLK_CPU_PLL]  = &clk_cpu_pll.aclk,
+	[AXXIA_CLK_SYS_PLL]  = &clk_sys_pll.aclk,
+	[AXXIA_CLK_SM0_PLL]  = &clk_sm0_pll.aclk,
+	[AXXIA_CLK_SM1_PLL]  = &clk_sm1_pll.aclk,
+	[AXXIA_CLK_FAB_DIV]  = &clk_fab_div.aclk,
+	[AXXIA_CLK_SYS_DIV]  = &clk_sys_div.aclk,
+	[AXXIA_CLK_NRCP_DIV] = &clk_nrcp_div.aclk,
+	[AXXIA_CLK_CPU0_DIV] = &clk_cpu0_div.aclk,
+	[AXXIA_CLK_CPU1_DIV] = &clk_cpu1_div.aclk,
+	[AXXIA_CLK_CPU2_DIV] = &clk_cpu2_div.aclk,
+	[AXXIA_CLK_CPU3_DIV] = &clk_cpu3_div.aclk,
+	[AXXIA_CLK_PER_DIV]  = &clk_per_div.aclk,
+	[AXXIA_CLK_MMC_DIV]  = &clk_mmc_div.aclk,
+	[AXXIA_CLK_FAB]      = &clk_fab_mux.aclk,
+	[AXXIA_CLK_SYS]      = &clk_sys_mux.aclk,
+	[AXXIA_CLK_NRCP]     = &clk_nrcp_mux.aclk,
+	[AXXIA_CLK_CPU0]     = &clk_cpu0_mux.aclk,
+	[AXXIA_CLK_CPU1]     = &clk_cpu1_mux.aclk,
+	[AXXIA_CLK_CPU2]     = &clk_cpu2_mux.aclk,
+	[AXXIA_CLK_CPU3]     = &clk_cpu3_mux.aclk,
+	[AXXIA_CLK_PER]      = &clk_per_mux.aclk,
+	[AXXIA_CLK_MMC]      = &clk_mmc_mux.aclk,
+};
+
+static const struct regmap_config axmclk_regmap_config = {
+	.reg_bits	= 32,
+	.reg_stride	= 4,
+	.val_bits	= 32,
+	.max_register	= 0x1fffc,
+	.fast_io	= true,
+};
+
+static const struct of_device_id axmclk_match_table[] = {
+	{ .compatible = "lsi,axm5516-clks" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, axmclk_match_table);
+
+struct axmclk_priv {
+	struct clk_onecell_data onecell;
+	struct clk *clks[];
+};
+
+static int axmclk_probe(struct platform_device *pdev)
+{
+	void __iomem *base;
+	struct resource *res;
+	int i, ret;
+	struct device *dev = &pdev->dev;
+	struct clk *clk;
+	struct regmap *regmap;
+	size_t num_clks;
+	struct axmclk_priv *priv;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap = devm_regmap_init_mmio(dev, base, &axmclk_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	num_clks = ARRAY_SIZE(axmclk_clocks);
+	pr_info("axmclk: supporting %u clocks\n", num_clks);
+	priv = devm_kzalloc(dev, sizeof(*priv) + sizeof(*priv->clks) * num_clks,
+			    GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->onecell.clks = priv->clks;
+	priv->onecell.clk_num = num_clks;
+
+	/* Update each entry with the allocated regmap and register the clock
+	 * with the common clock framework
+	 */
+	for (i = 0; i < num_clks; i++) {
+		axmclk_clocks[i]->regmap = regmap;
+		clk = devm_clk_register(dev, &axmclk_clocks[i]->hw);
+		if (IS_ERR(clk))
+			return PTR_ERR(clk);
+		priv->clks[i] = clk;
+	}
+
+	ret = of_clk_add_provider(dev->of_node,
+				  of_clk_src_onecell_get, &priv->onecell);
+
+	return ret;
+}
+
+static int axmclk_remove(struct platform_device *pdev)
+{
+	of_clk_del_provider(pdev->dev.of_node);
+	return 0;
+}
+
+static struct platform_driver axmclk_driver = {
+	.probe		= axmclk_probe,
+	.remove		= axmclk_remove,
+	.driver		= {
+		.name	= "clk-axm5516",
+		.owner	= THIS_MODULE,
+		.of_match_table = axmclk_match_table,
+	},
+};
+
+static int __init axmclk_init(void)
+{
+	return platform_driver_register(&axmclk_driver);
+}
+core_initcall(axmclk_init);
+
+static void __exit axmclk_exit(void)
+{
+	platform_driver_unregister(&axmclk_driver);
+}
+module_exit(axmclk_exit);
+
+MODULE_DESCRIPTION("AXM5516 clock driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:clk-axm5516");
-- 
1.8.3.2

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