[PATCH v7 18/42] clk: davinci: New driver for TI DA8XX CFGCHIP clocks

[David Lechner]

This adds a new driver for the gate and multiplexer clocks in the
CFGCHIPn syscon registers on TI DA8XX-type SoCs.

Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
---

v7 changes:
- convert to platform device

v6 changes:
- added DIV4.5 and ASYNC1 clocks
- refactored code to be more generic
- added functions for registering clocks from board files (no longer device
  tree only)
- use pr_fmt macro


 drivers/clk/davinci/Makefile                    |   2 +
 drivers/clk/davinci/da8xx-cfgchip.c             | 435 ++++++++++++++++++++++++
 include/linux/platform_data/clk-da8xx-cfgchip.h |  21 ++
 3 files changed, 458 insertions(+)
 create mode 100644 drivers/clk/davinci/da8xx-cfgchip.c
 create mode 100644 include/linux/platform_data/clk-da8xx-cfgchip.h

diff --git a/drivers/clk/davinci/Makefile b/drivers/clk/davinci/Makefile
index 6c388d4..11178b7 100644
--- a/drivers/clk/davinci/Makefile
+++ b/drivers/clk/davinci/Makefile
@@ -1,6 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
 
 ifeq ($(CONFIG_COMMON_CLK), y)
+obj-$(CONFIG_ARCH_DAVINCI_DA8XX)	+= da8xx-cfgchip.o
+
 obj-y += pll.o
 obj-$(CONFIG_ARCH_DAVINCI_DA830)	+= pll-da830.o
 obj-$(CONFIG_ARCH_DAVINCI_DA850)	+= pll-da850.o
diff --git a/drivers/clk/davinci/da8xx-cfgchip.c b/drivers/clk/davinci/da8xx-cfgchip.c
new file mode 100644
index 0000000..386da99
--- /dev/null
+++ b/drivers/clk/davinci/da8xx-cfgchip.c
@@ -0,0 +1,435 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Clock driver for DA8xx/AM17xx/AM18xx/OMAP-L13x CFGCHIP
+ *
+ * Copyright (C) 2018 David Lechner <david@xxxxxxxxxxxxxx>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/init.h>
+#include <linux/mfd/da8xx-cfgchip.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/platform_data/clk-da8xx-cfgchip.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+/* --- Gate clocks --- */
+
+#define DA8XX_GATE_CLOCK_IS_DIV4P5	BIT(1)
+
+struct da8xx_cfgchip_gate_clk_info {
+	const char *name;
+	u32 cfgchip;
+	u32 bit;
+	u32 flags;
+};
+
+struct da8xx_cfgchip_gate_clk {
+	struct clk_hw hw;
+	struct regmap *regmap;
+	u32 reg;
+	u32 mask;
+};
+
+#define to_da8xx_cfgchip_gate_clk(_hw) \
+	container_of((_hw), struct da8xx_cfgchip_gate_clk, hw)
+
+static int da8xx_cfgchip_gate_clk_enable(struct clk_hw *hw)
+{
+	struct da8xx_cfgchip_gate_clk *clk = to_da8xx_cfgchip_gate_clk(hw);
+
+	return regmap_write_bits(clk->regmap, clk->reg, clk->mask, clk->mask);
+}
+
+static void da8xx_cfgchip_gate_clk_disable(struct clk_hw *hw)
+{
+	struct da8xx_cfgchip_gate_clk *clk = to_da8xx_cfgchip_gate_clk(hw);
+
+	regmap_write_bits(clk->regmap, clk->reg, clk->mask, 0);
+}
+
+static int da8xx_cfgchip_gate_clk_is_enabled(struct clk_hw *hw)
+{
+	struct da8xx_cfgchip_gate_clk *clk = to_da8xx_cfgchip_gate_clk(hw);
+	unsigned int val;
+
+	regmap_read(clk->regmap, clk->reg, &val);
+
+	return !!(val & clk->mask);
+}
+
+static unsigned long da8xx_cfgchip_div4p5_recalc_rate(struct clk_hw *hw,
+						      unsigned long parent_rate)
+{
+	/* this clock divides by 4.5 */
+	return parent_rate * 2 / 9;
+}
+
+static const struct clk_ops da8xx_cfgchip_gate_clk_ops = {
+	.enable		= da8xx_cfgchip_gate_clk_enable,
+	.disable	= da8xx_cfgchip_gate_clk_disable,
+	.is_enabled	= da8xx_cfgchip_gate_clk_is_enabled,
+};
+
+static const struct clk_ops da8xx_cfgchip_div4p5_clk_ops = {
+	.enable		= da8xx_cfgchip_gate_clk_enable,
+	.disable	= da8xx_cfgchip_gate_clk_disable,
+	.is_enabled	= da8xx_cfgchip_gate_clk_is_enabled,
+	.recalc_rate	= da8xx_cfgchip_div4p5_recalc_rate,
+};
+
+static struct da8xx_cfgchip_gate_clk * __init
+da8xx_cfgchip_gate_clk_register(struct device *dev,
+				const struct da8xx_cfgchip_gate_clk_info *info,
+				struct regmap *regmap)
+{
+	struct clk *parent;
+	const char *parent_name;
+	struct da8xx_cfgchip_gate_clk *gate;
+	struct clk_init_data init;
+	int ret;
+
+	parent = devm_clk_get(dev, NULL);
+	if (IS_ERR(parent))
+		return ERR_CAST(parent);
+
+	parent_name = __clk_get_name(parent);
+
+	gate = devm_kzalloc(dev, sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = info->name;
+	if (info->flags & DA8XX_GATE_CLOCK_IS_DIV4P5)
+		init.ops = &da8xx_cfgchip_div4p5_clk_ops;
+	else
+		init.ops = &da8xx_cfgchip_gate_clk_ops;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+	init.flags = 0;
+
+	gate->hw.init = &init;
+	gate->regmap = regmap;
+	gate->reg = info->cfgchip;
+	gate->mask = info->bit;
+
+	ret = devm_clk_hw_register(dev, &gate->hw);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	return gate;
+}
+
+static const struct da8xx_cfgchip_gate_clk_info da8xx_tbclksync_info __initconst = {
+	.name = "ehrpwm_tbclk",
+	.cfgchip = CFGCHIP(1),
+	.bit = CFGCHIP1_TBCLKSYNC,
+};
+
+static int __init da8xx_cfgchip_register_tbclk(struct device *dev,
+					       struct regmap *regmap)
+{
+	struct da8xx_cfgchip_gate_clk *gate;
+
+	gate = da8xx_cfgchip_gate_clk_register(dev, &da8xx_tbclksync_info,
+					       regmap);
+	if (IS_ERR(gate))
+		return PTR_ERR(gate);
+
+	clk_hw_register_clkdev(&gate->hw, "tbclk", "ehrpwm.0");
+	clk_hw_register_clkdev(&gate->hw, "tbclk", "ehrpwm.1");
+
+	return 0;
+}
+
+static const struct da8xx_cfgchip_gate_clk_info da8xx_div4p5ena_info __initconst = {
+	.name = "div4.5",
+	.cfgchip = CFGCHIP(3),
+	.bit = CFGCHIP3_DIV45PENA,
+	.flags = DA8XX_GATE_CLOCK_IS_DIV4P5,
+};
+
+static int __init da8xx_cfgchip_register_div4p5(struct device *dev,
+						struct regmap *regmap)
+{
+	struct da8xx_cfgchip_gate_clk *gate;
+
+	gate = da8xx_cfgchip_gate_clk_register(dev, &da8xx_div4p5ena_info, regmap);
+	if (IS_ERR(gate))
+		return PTR_ERR(gate);
+
+	return 0;
+}
+
+static int __init
+of_da8xx_cfgchip_gate_clk_init(struct device *dev,
+			       const struct da8xx_cfgchip_gate_clk_info *info,
+			       struct regmap *regmap)
+{
+	struct da8xx_cfgchip_gate_clk *gate;
+
+	gate = da8xx_cfgchip_gate_clk_register(dev, info, regmap);
+	if (IS_ERR(gate))
+		return PTR_ERR(gate);
+
+	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, gate);
+}
+
+static int __init of_da8xx_tbclksync_init(struct device *dev,
+					  struct regmap *regmap)
+{
+	return of_da8xx_cfgchip_gate_clk_init(dev, &da8xx_tbclksync_info, regmap);
+}
+
+static int __init of_da8xx_div4p5ena_init(struct device *dev,
+					  struct regmap *regmap)
+{
+	return of_da8xx_cfgchip_gate_clk_init(dev, &da8xx_div4p5ena_info, regmap);
+}
+
+/* --- MUX clocks --- */
+
+struct da8xx_cfgchip_mux_clk_info {
+	const char *name;
+	const char *parent0;
+	const char *parent1;
+	u32 cfgchip;
+	u32 bit;
+};
+
+struct da8xx_cfgchip_mux_clk {
+	struct clk_hw hw;
+	struct regmap *regmap;
+	u32 reg;
+	u32 mask;
+};
+
+#define to_da8xx_cfgchip_mux_clk(_hw) \
+	container_of((_hw), struct da8xx_cfgchip_mux_clk, hw)
+
+static int da8xx_cfgchip_mux_clk_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct da8xx_cfgchip_mux_clk *clk = to_da8xx_cfgchip_mux_clk(hw);
+	unsigned int val = index ? clk->mask : 0;
+
+	return regmap_write_bits(clk->regmap, clk->reg, clk->mask, val);
+}
+
+static u8 da8xx_cfgchip_mux_clk_get_parent(struct clk_hw *hw)
+{
+	struct da8xx_cfgchip_mux_clk *clk = to_da8xx_cfgchip_mux_clk(hw);
+	unsigned int val;
+
+	regmap_read(clk->regmap, clk->reg, &val);
+
+	return (val & clk->mask) ? 1 : 0;
+}
+
+static const struct clk_ops da8xx_cfgchip_mux_clk_ops = {
+	.set_parent	= da8xx_cfgchip_mux_clk_set_parent,
+	.get_parent	= da8xx_cfgchip_mux_clk_get_parent,
+};
+
+static struct da8xx_cfgchip_mux_clk * __init
+da8xx_cfgchip_mux_clk_register(struct device *dev,
+			       const struct da8xx_cfgchip_mux_clk_info *info,
+			       struct regmap *regmap)
+{
+	const char * const parent_names[] = { info->parent0, info->parent1 };
+	struct da8xx_cfgchip_mux_clk *mux;
+	struct clk_init_data init;
+	int ret;
+
+	mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
+	if (!mux)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = info->name;
+	init.ops = &da8xx_cfgchip_mux_clk_ops;
+	init.parent_names = parent_names;
+	init.num_parents = 2;
+	init.flags = 0;
+
+	mux->hw.init = &init;
+	mux->regmap = regmap;
+	mux->reg = info->cfgchip;
+	mux->mask = info->bit;
+
+	ret = devm_clk_hw_register(dev, &mux->hw);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	return mux;
+}
+
+static const struct da8xx_cfgchip_mux_clk_info da850_async1_info __initconst = {
+	.name = "async1",
+	.parent0 = "pll0_sysclk3",
+	.parent1 = "div4.5",
+	.cfgchip = CFGCHIP(3),
+	.bit = CFGCHIP3_EMA_CLKSRC,
+};
+
+static int __init da8xx_cfgchip_register_async1(struct device *dev,
+						struct regmap *regmap)
+{
+	struct da8xx_cfgchip_mux_clk *mux;
+
+	mux = da8xx_cfgchip_mux_clk_register(dev, &da850_async1_info, regmap);
+	if (IS_ERR(mux))
+		return PTR_ERR(mux);
+
+	return 0;
+}
+
+static const struct da8xx_cfgchip_mux_clk_info da850_async3_info __initconst = {
+	.name = "async3",
+	.parent0 = "pll0_sysclk2",
+	.parent1 = "pll1_sysclk2",
+	.cfgchip = CFGCHIP(3),
+	.bit = CFGCHIP3_ASYNC3_CLKSRC,
+};
+
+static int __init da850_cfgchip_register_async3(struct device *dev,
+						struct regmap *regmap)
+{
+	struct da8xx_cfgchip_mux_clk *mux;
+	struct clk_hw *parent;
+
+	mux = da8xx_cfgchip_mux_clk_register(dev, &da850_async3_info, regmap);
+	if (IS_ERR(mux))
+		return PTR_ERR(mux);
+
+	/* pll1_sysclk2 is not affected by CPU scaling, so use it for async3 */
+	parent = clk_hw_get_parent_by_index(&mux->hw, 1);
+	if (parent)
+		clk_set_parent(mux->hw.clk, parent->clk);
+	else
+		dev_warn(dev, "Failed to find async3 parent clock\n");
+
+	return 0;
+}
+
+static int __init
+of_da8xx_cfgchip_init_mux_clock(struct device *dev,
+				const struct da8xx_cfgchip_mux_clk_info *info,
+				struct regmap *regmap)
+{
+	struct da8xx_cfgchip_mux_clk *mux;
+
+	mux = da8xx_cfgchip_mux_clk_register(dev, info, regmap);
+	if (IS_ERR(mux))
+		return PTR_ERR(mux);
+
+	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, &mux->hw);
+}
+
+static int __init of_da850_async1_init(struct device *dev, struct regmap *regmap)
+{
+	return of_da8xx_cfgchip_init_mux_clock(dev, &da850_async1_info, regmap);
+}
+
+static int __init of_da850_async3_init(struct device *dev, struct regmap *regmap)
+{
+	return of_da8xx_cfgchip_init_mux_clock(dev, &da850_async3_info, regmap);
+}
+
+/* --- platform device --- */
+
+static const struct of_device_id da8xx_cfgchip_of_match[] = {
+	{
+		.compatible = "ti,da830-tbclksync",
+		.data = of_da8xx_tbclksync_init,
+	},
+	{
+		.compatible = "ti,da830-div4p5ena",
+		.data = of_da8xx_div4p5ena_init,
+	},
+	{
+		.compatible = "ti,da850-async1-clksrc",
+		.data = of_da850_async1_init,
+	},
+	{
+		.compatible = "ti,da850-async3-clksrc",
+		.data = of_da850_async3_init,
+	},
+	{ }
+};
+
+static const struct platform_device_id da8xx_cfgchip_id_table[] = {
+	{
+		.name = "da830-tbclksync",
+		.driver_data = (kernel_ulong_t)da8xx_cfgchip_register_tbclk,
+	},
+	{
+		.name = "da830-div4p5ena",
+		.driver_data = (kernel_ulong_t)da8xx_cfgchip_register_div4p5,
+	},
+	{
+		.name = "da850-async1-clksrc",
+		.driver_data = (kernel_ulong_t)da8xx_cfgchip_register_async1,
+	},
+	{
+		.name = "da850-async3-clksrc",
+		.driver_data = (kernel_ulong_t)da850_cfgchip_register_async3,
+	},
+	{ }
+};
+
+typedef int (*da8xx_cfgchip_init)(struct device *dev, void __iomem *base);
+
+static int da8xx_cfgchip_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct da8xx_cfgchip_clk_platform_data *pdata = dev->platform_data;
+	const struct of_device_id *of_id;
+	da8xx_cfgchip_init clk_init = NULL;
+	struct regmap *regmap = NULL;
+
+	of_id = of_match_device(da8xx_cfgchip_of_match, dev);
+	if (of_id) {
+		struct device_node *parent;
+
+		clk_init = of_id->data;
+		parent = of_get_parent(dev->of_node);
+		regmap = syscon_node_to_regmap(parent);
+		of_node_put(parent);
+	} else if (pdev->id_entry && pdata) {
+		clk_init = (void *)pdev->id_entry->driver_data;
+		regmap = pdata->cfgchip;
+	}
+
+	if (!clk_init) {
+		dev_err(dev, "unable to find driver data\n");
+		return -EINVAL;
+	}
+
+	if (IS_ERR_OR_NULL(regmap)) {
+		dev_err(dev, "no regmap for CFGCHIP syscon\n");
+		return regmap ? PTR_ERR(regmap) : -ENOENT;
+	}
+
+	return clk_init(dev, regmap);
+}
+
+static struct platform_driver da8xx_cfgchip_driver = {
+	.probe		= da8xx_cfgchip_probe,
+	.driver		= {
+		.name		= "da8xx-cfgchip-clk",
+		.of_match_table	= da8xx_cfgchip_of_match,
+	},
+	.id_table	= da8xx_cfgchip_id_table,
+};
+
+static int __init da8xx_cfgchip_driver_init(void)
+{
+	return platform_driver_register(&da8xx_cfgchip_driver);
+}
+
+/* has to be postcore_initcall because PSC devices depend on the async3 clock */
+postcore_initcall(da8xx_cfgchip_driver_init);
diff --git a/include/linux/platform_data/clk-da8xx-cfgchip.h b/include/linux/platform_data/clk-da8xx-cfgchip.h
new file mode 100644
index 0000000..de0f77d
--- /dev/null
+++ b/include/linux/platform_data/clk-da8xx-cfgchip.h
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * clk-da8xx-cfgchip - TI DaVinci DA8xx CFGCHIP clock driver
+ *
+ * Copyright (C) 2018 David Lechner <david@xxxxxxxxxxxxxx>
+ */
+
+#ifndef __LINUX_PLATFORM_DATA_CLK_DA8XX_CFGCHIP_H__
+#define __LINUX_PLATFORM_DATA_CLK_DA8XX_CFGCHIP_H__
+
+#include <linux/regmap.h>
+
+/**
+ * da8xx_cfgchip_clk_platform_data
+ * @cfgchip: CFGCHIP syscon regmap
+ */
+struct da8xx_cfgchip_clk_platform_data {
+	struct regmap *cfgchip;
+};
+
+#endif /* __LINUX_PLATFORM_DATA_CLK_DA8XX_CFGCHIP_H__ */
-- 
2.7.4