clk: Add Altera SoCFPGA clk support

The SoCFPGA currently has all clocks described in the devicetree which
makes common clock support a straight forward task.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 418 insertions, 0 deletions

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 2978c2eb33..1cf0ccb968 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -12,3 +12,8 @@ config COMMON_CLK_OF_PROVIDER
 	bool
 	help
 	  Clock driver provides OF-Tree based clock lookup.
+
+config CLK_SOCFPGA
+	bool
+	select COMMON_CLK_OF_PROVIDER
+	default y if ARCH_SOCFPGA && OFDEVICE
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index a121947af0..f5c05920b1 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_CLKDEV_LOOKUP)	+= clkdev.o
 obj-$(CONFIG_ARCH_MVEBU)	+= mvebu/
 obj-$(CONFIG_ARCH_MXS)		+= mxs/
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
+obj-$(CONFIG_CLK_SOCFPGA)	+= socfpga.o
diff --git a/drivers/clk/socfpga.c b/drivers/clk/socfpga.c
new file mode 100644
index 0000000000..33a55cbeeb
--- /dev/null
+++ b/drivers/clk/socfpga.c
@@ -0,0 +1,412 @@
+/*
+ *  Copyright (C) 2013 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <common.h>
+#include <init.h>
+#include <driver.h>
+#include <linux/clk.h>
+#include <io.h>
+#include <malloc.h>
+#include <linux/clkdev.h>
+#include <linux/err.h>
+
+/* Clock Manager offsets */
+#define CLKMGR_CTRL	0x0
+#define CLKMGR_BYPASS	0x4
+#define CLKMGR_L4SRC	0x70
+#define CLKMGR_PERPLL_SRC	0xAC
+
+/* Clock bypass bits */
+#define MAINPLL_BYPASS		(1<<0)
+#define SDRAMPLL_BYPASS		(1<<1)
+#define SDRAMPLL_SRC_BYPASS	(1<<2)
+#define PERPLL_BYPASS		(1<<3)
+#define PERPLL_SRC_BYPASS	(1<<4)
+
+#define SOCFPGA_PLL_BG_PWRDWN		0
+#define SOCFPGA_PLL_EXT_ENA		1
+#define SOCFPGA_PLL_PWR_DOWN		2
+#define SOCFPGA_PLL_DIVF_MASK		0x0000FFF8
+#define SOCFPGA_PLL_DIVF_SHIFT	3
+#define SOCFPGA_PLL_DIVQ_MASK		0x003F0000
+#define SOCFPGA_PLL_DIVQ_SHIFT	16
+#define SOCFGPA_MAX_PARENTS	3
+
+#define SOCFPGA_DB_CLK			"gpio_db_clk"
+
+#define div_mask(width)	((1 << (width)) - 1)
+#define streq(a, b) (strcmp((a), (b)) == 0)
+
+static void __iomem *clk_mgr_base_addr;
+
+char *of_clk_get_parent_name(struct device_node *np, unsigned int index)
+{
+	struct of_phandle_args clkspec;
+	const char *clk_name;
+	int rc;
+
+	rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
+			&clkspec);
+	if (rc)
+		return NULL;
+
+	if (of_property_read_string_index(clkspec.np, "clock-output-names",
+				clkspec.args_count ? clkspec.args[0] : 0,
+				&clk_name) < 0)
+		clk_name = clkspec.np->name;
+
+	return xstrdup(clk_name);
+}
+
+static struct clk *socfpga_fixed_clk(struct device_node *node)
+{
+	uint32_t f = 0;
+
+	of_property_read_u32(node, "clock-frequency", &f);
+
+	return clk_fixed(node->name, f);
+}
+
+struct clk_pll {
+	struct clk clk;
+	const char *parent;
+	unsigned regofs;
+};
+
+static unsigned long clk_pll_recalc_rate(struct clk *clk,
+		unsigned long parent_rate)
+{
+	struct clk_pll *pll = container_of(clk, struct clk_pll, clk);
+	unsigned long divf, divq, vco_freq, reg;
+	unsigned long bypass;
+
+	reg = readl(clk_mgr_base_addr + pll->regofs);
+
+	bypass = readl(clk_mgr_base_addr + CLKMGR_BYPASS);
+	if (bypass & MAINPLL_BYPASS)
+		return parent_rate;
+
+	divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT;
+	divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT;
+	vco_freq = parent_rate * (divf + 1);
+
+	return vco_freq / (1 + divq);
+}
+
+static struct clk_ops clk_pll_ops = {
+	.recalc_rate = clk_pll_recalc_rate,
+};
+
+static struct clk *socfpga_pll_clk(struct device_node *node)
+{
+	struct clk_pll *pll;
+	int ret;
+
+	pll = xzalloc(sizeof(*pll));
+
+	pll->parent = of_clk_get_parent_name(node, 0);
+	if (!pll->parent)
+		return ERR_PTR(-EINVAL);
+
+	pll->clk.parent_names = &pll->parent;
+	pll->clk.num_parents = 1;
+	pll->clk.name = xstrdup(node->name);
+	pll->clk.ops = &clk_pll_ops;
+
+	of_property_read_u32(node, "reg", &pll->regofs);
+
+	ret = clk_register(&pll->clk);
+	if (ret) {
+		free(pll);
+		return ERR_PTR(ret);
+	}
+
+	return &pll->clk;
+}
+
+struct clk_periph {
+	struct clk clk;
+	const char *parent;
+	unsigned regofs;
+	unsigned int fixed_div;
+};
+
+static unsigned long clk_periph_recalc_rate(struct clk *clk,
+		unsigned long parent_rate)
+{
+	struct clk_periph *periph = container_of(clk, struct clk_periph, clk);
+	u32 div;
+
+	if (periph->fixed_div)
+		div = periph->fixed_div;
+	else
+		div = ((readl(clk_mgr_base_addr + periph->regofs) & 0x1ff) + 1);
+
+	return parent_rate / div;
+}
+
+static struct clk_ops clk_periph_ops = {
+	.recalc_rate = clk_periph_recalc_rate,
+};
+
+static struct clk *socfpga_periph_clk(struct device_node *node)
+{
+	struct clk_periph *periph;
+	int ret;
+
+	periph = xzalloc(sizeof(*periph));
+
+	periph->parent = of_clk_get_parent_name(node, 0);
+	if (!periph->parent)
+		return ERR_PTR(-EINVAL);
+
+	periph->clk.parent_names = &periph->parent;
+	periph->clk.num_parents = 1;
+	periph->clk.name = xstrdup(node->name);
+	periph->clk.ops = &clk_periph_ops;
+
+	of_property_read_u32(node, "reg", &periph->regofs);
+	of_property_read_u32(node, "fixed-divider", &periph->fixed_div);
+
+	ret = clk_register(&periph->clk);
+	if (ret) {
+		free(periph);
+		return ERR_PTR(ret);
+	}
+
+	return &periph->clk;
+}
+
+struct clk_socfpga {
+	struct clk clk;
+	const char *parent;
+	void __iomem *reg;
+	void __iomem *div_reg;
+	void __iomem *parent_reg;
+	unsigned int fixed_div;
+	unsigned int bit_idx;
+	unsigned int shift;
+	unsigned int width;
+	unsigned int parent_shift;
+	unsigned int parent_width;
+	const char *parent_names[SOCFGPA_MAX_PARENTS];
+};
+
+static int clk_socfpga_enable(struct clk *clk)
+{
+	struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+	u32 val;
+
+	val = readl(cs->reg);
+	val |= 1 << cs->shift;
+	writel(val, cs->reg);
+
+	return 0;
+}
+
+static void clk_socfpga_disable(struct clk *clk)
+{
+	struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+	u32 val;
+
+	val = readl(cs->reg);
+	val &= ~(1 << cs->shift);
+	writel(val, cs->reg);
+}
+
+static int clk_socfpga_is_enabled(struct clk *clk)
+{
+	struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+	u32 val;
+
+	val = readl(cs->reg);
+
+	if (val & (1 << cs->shift))
+		return 1;
+	else
+		return 0;
+}
+
+static unsigned long clk_socfpga_recalc_rate(struct clk *clk,
+	unsigned long parent_rate)
+{
+	struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+	u32 div = 1, val;
+
+	if (cs->fixed_div) {
+		div = cs->fixed_div;
+	} else if (cs->div_reg) {
+		val = readl(cs->div_reg) >> cs->shift;
+		val &= div_mask(cs->width);
+		if (streq(clk->name, SOCFPGA_DB_CLK))
+			div = val + 1;
+		else
+			div = (1 << val);
+	}
+
+	return parent_rate / div;
+}
+
+static int clk_socfpga_get_parent(struct clk *clk)
+{
+	struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+
+	return readl(cs->parent_reg) >> cs->parent_shift &
+		((1 << cs->parent_width) - 1);
+}
+
+static int clk_socfpga_set_parent(struct clk *clk, u8 parent)
+{
+	struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+	uint32_t val;
+
+	val = readl(cs->parent_reg);
+	val &= ~(((1 << cs->parent_width) - 1) << cs->parent_shift);
+	val |= parent << cs->parent_shift;
+	writel(val, cs->parent_reg);
+
+	return 0;
+}
+
+static struct clk_ops clk_socfpga_ops = {
+	.recalc_rate = clk_socfpga_recalc_rate,
+	.enable = clk_socfpga_enable,
+	.disable = clk_socfpga_disable,
+	.is_enabled = clk_socfpga_is_enabled,
+	.get_parent = clk_socfpga_get_parent,
+	.set_parent = clk_socfpga_set_parent,
+};
+
+static struct clk *socfpga_gate_clk(struct device_node *node)
+{
+	u32 clk_gate[2];
+	u32 div_reg[3];
+	u32 parent_reg[3];
+	u32 fixed_div;
+	struct clk_socfpga *cs;
+	int ret;
+	int i = 0;
+
+	cs = xzalloc(sizeof(*cs));
+
+	ret = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
+	if (ret)
+		clk_gate[0] = 0;
+
+	if (clk_gate[0]) {
+		cs->reg = clk_mgr_base_addr + clk_gate[0];
+		cs->bit_idx = clk_gate[1];
+	}
+
+	ret = of_property_read_u32(node, "fixed-divider", &fixed_div);
+	if (ret)
+		cs->fixed_div = 0;
+	else
+		cs->fixed_div = fixed_div;
+
+	ret = of_property_read_u32_array(node, "div-reg", div_reg, 3);
+	if (!ret) {
+		cs->div_reg = clk_mgr_base_addr + div_reg[0];
+		cs->shift = div_reg[1];
+		cs->width = div_reg[2];
+	}
+
+	ret = of_property_read_u32_array(node, "parent-reg", parent_reg, 3);
+	if (!ret) {
+		cs->parent_reg = clk_mgr_base_addr + parent_reg[0];
+		cs->parent_shift = parent_reg[1];
+		cs->parent_width = parent_reg[2];
+	}
+
+	for (i = 0; i < SOCFGPA_MAX_PARENTS; i++) {
+		cs->parent_names[i] = of_clk_get_parent_name(node, i);
+		if (!cs->parent_names[i])
+			break;
+	}
+
+	cs->clk.parent_names = cs->parent_names;
+	cs->clk.num_parents = i;
+	cs->clk.name = xstrdup(node->name);
+	cs->clk.ops = &clk_socfpga_ops;
+
+	ret = clk_register(&cs->clk);
+	if (ret) {
+		free(cs);
+		return ERR_PTR(ret);
+	}
+
+	return &cs->clk;
+}
+
+static void socfpga_register_clocks(struct device_d *dev, struct device_node *node)
+{
+	struct device_node *child;
+	struct clk *clk;
+
+	for_each_child_of_node(node, child) {
+		socfpga_register_clocks(dev, child);
+	}
+
+	if (of_device_is_compatible(node, "fixed-clock"))
+		clk = socfpga_fixed_clk(node);
+	else if (of_device_is_compatible(node, "altr,socfpga-pll-clock"))
+		clk = socfpga_pll_clk(node);
+	else if (of_device_is_compatible(node, "altr,socfpga-perip-clk"))
+		clk = socfpga_periph_clk(node);
+	else if (of_device_is_compatible(node, "altr,socfpga-gate-clk"))
+		clk = socfpga_gate_clk(node);
+	else
+		return;
+
+	of_clk_add_provider(node, of_clk_src_simple_get, clk);
+}
+
+static int socfpga_ccm_probe(struct device_d *dev)
+{
+	void __iomem *regs;
+	struct device_node *clknode;
+
+	regs = dev_request_mem_region(dev, 0);
+	if (!regs)
+		return -EBUSY;
+
+	clk_mgr_base_addr = regs;
+
+	clknode = of_get_child_by_name(dev->device_node, "clocks");
+	if (!clknode)
+		return -EINVAL;
+
+	socfpga_register_clocks(dev, clknode);
+
+	return 0;
+}
+
+static __maybe_unused struct of_device_id socfpga_ccm_dt_ids[] = {
+	{
+		.compatible = "altr,clk-mgr",
+	}, {
+		/* sentinel */
+	}
+};
+
+static struct driver_d socfpga_ccm_driver = {
+	.probe	= socfpga_ccm_probe,
+	.name	= "socfpga-ccm",
+	.of_compatible = DRV_OF_COMPAT(socfpga_ccm_dt_ids),
+};
+
+static int socfpga_ccm_init(void)
+{
+	return platform_driver_register(&socfpga_ccm_driver);
+}
+core_initcall(socfpga_ccm_init);