[PATCH v5 3/3] clk: meson: add sub MMC clock controller driver

[Jianxin Pan <jianxin.pan@amlogic.com>]

From: Yixun Lan <yixun.lan@amlogic.com>

The patch will add a MMC clock controller driver which used by MMC or NAND,
It provide a mux and divider clock, and three phase clocks - core, tx, tx.

Two clocks are provided as the parent of MMC clock controller from
upper layer clock controller - eg "amlogic,axg-clkc" in AXG platform.

To specify which clock the MMC or NAND driver may consume,
the preprocessor macros in the dt-bindings/clock/amlogic,mmc-clkc.h header
can be used in the device tree sources.

Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
Signed-off-by: Jianxin Pan <jianxin.pan@amlogic.com>
---
 drivers/clk/meson/Kconfig      |  10 ++
 drivers/clk/meson/Makefile     |   1 +
 drivers/clk/meson/clk-regmap.c |  27 +++-
 drivers/clk/meson/clk-regmap.h |   1 +
 drivers/clk/meson/mmc-clkc.c   | 296 +++++++++++++++++++++++++++++++++++++++++
 5 files changed, 334 insertions(+), 1 deletion(-)
 create mode 100644 drivers/clk/meson/mmc-clkc.c

diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
index efaa70f..8b8ccbc 100644
--- a/drivers/clk/meson/Kconfig
+++ b/drivers/clk/meson/Kconfig
@@ -15,6 +15,16 @@ config COMMON_CLK_MESON_AO
 	select COMMON_CLK_REGMAP_MESON
 	select RESET_CONTROLLER
 
+config COMMON_CLK_MMC_MESON
+	tristate "Meson MMC Sub Clock Controller Driver"
+	depends on COMMON_CLK_AMLOGIC
+	select MFD_SYSCON
+	select REGMAP
+	help
+	  Support for the MMC sub clock controller on Amlogic Meson Platform,
+	  which include S905 (GXBB, GXL), A113D/X (AXG) devices.
+	  Say Y if you want this clock enabled.
+
 config COMMON_CLK_REGMAP_MESON
 	bool
 	select REGMAP
diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
index 39ce566..31c16d5 100644
--- a/drivers/clk/meson/Makefile
+++ b/drivers/clk/meson/Makefile
@@ -9,4 +9,5 @@ obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
 obj-$(CONFIG_COMMON_CLK_GXBB)	 += gxbb.o gxbb-aoclk.o gxbb-aoclk-32k.o
 obj-$(CONFIG_COMMON_CLK_AXG)	 += axg.o axg-aoclk.o
 obj-$(CONFIG_COMMON_CLK_AXG_AUDIO)	+= axg-audio.o
+obj-$(CONFIG_COMMON_CLK_MMC_MESON) 	+= mmc-clkc.o
 obj-$(CONFIG_COMMON_CLK_REGMAP_MESON)	+= clk-regmap.o
diff --git a/drivers/clk/meson/clk-regmap.c b/drivers/clk/meson/clk-regmap.c
index 305ee30..f96314d 100644
--- a/drivers/clk/meson/clk-regmap.c
+++ b/drivers/clk/meson/clk-regmap.c
@@ -113,8 +113,25 @@ static int clk_regmap_div_set_rate(struct clk_hw *hw, unsigned long rate,
 				  clk_div_mask(div->width) << div->shift, val);
 };
 
-/* Would prefer clk_regmap_div_ro_ops but clashes with qcom */
+static void clk_regmap_div_init(struct clk_hw *hw)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(clk->map, div->offset, &val);
+	if (ret)
+		return;
 
+	val &= (clk_div_mask(div->width) << div->shift);
+	if (!val)
+		regmap_update_bits(clk->map, div->offset,
+				   clk_div_mask(div->width) << div->shift,
+				   clk_div_mask(div->width));
+}
+
+/* Would prefer clk_regmap_div_ro_ops but clashes with qcom */
 const struct clk_ops clk_regmap_divider_ops = {
 	.recalc_rate = clk_regmap_div_recalc_rate,
 	.round_rate = clk_regmap_div_round_rate,
@@ -122,6 +139,14 @@ static int clk_regmap_div_set_rate(struct clk_hw *hw, unsigned long rate,
 };
 EXPORT_SYMBOL_GPL(clk_regmap_divider_ops);
 
+const struct clk_ops clk_regmap_divider_with_init_ops = {
+	.recalc_rate = clk_regmap_div_recalc_rate,
+	.round_rate = clk_regmap_div_round_rate,
+	.set_rate = clk_regmap_div_set_rate,
+	.init = clk_regmap_div_init,
+};
+EXPORT_SYMBOL_GPL(clk_regmap_divider_with_init_ops);
+
 const struct clk_ops clk_regmap_divider_ro_ops = {
 	.recalc_rate = clk_regmap_div_recalc_rate,
 	.round_rate = clk_regmap_div_round_rate,
diff --git a/drivers/clk/meson/clk-regmap.h b/drivers/clk/meson/clk-regmap.h
index ed2d434..0ab7d37 100644
--- a/drivers/clk/meson/clk-regmap.h
+++ b/drivers/clk/meson/clk-regmap.h
@@ -109,5 +109,6 @@ struct clk_regmap_mux_data {
 
 extern const struct clk_ops clk_regmap_mux_ops;
 extern const struct clk_ops clk_regmap_mux_ro_ops;
+extern const struct clk_ops clk_regmap_divider_with_init_ops;
 
 #endif /* __CLK_REGMAP_H */
diff --git a/drivers/clk/meson/mmc-clkc.c b/drivers/clk/meson/mmc-clkc.c
new file mode 100644
index 0000000..5555e3f
--- /dev/null
+++ b/drivers/clk/meson/mmc-clkc.c
@@ -0,0 +1,296 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Amlogic Meson MMC Sub Clock Controller Driver
+ *
+ * Copyright (c) 2017 Baylibre SAS.
+ * Author: Jerome Brunet <jbrunet@baylibre.com>
+ *
+ * Copyright (c) 2018 Amlogic, inc.
+ * Author: Yixun Lan <yixun.lan@amlogic.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/of_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
+#include <dt-bindings/clock/amlogic,mmc-clkc.h>
+
+#include "clkc.h"
+
+/* clock ID used by internal driver */
+#define CLKID_MMC_MUX			0
+
+#define   SD_EMMC_CLOCK		0
+#define   CLK_DELAY_STEP_PS		200
+#define   CLK_PHASE_STEP		30
+#define   CLK_PHASE_POINT_NUM		(360 / CLK_PHASE_STEP)
+
+#define MUX_CLK_NUM_PARENTS		2
+#define MMC_MAX_CLKS			5
+
+struct mmc_clkc_data {
+	struct meson_clk_phase_delay_data	tx;
+	struct meson_clk_phase_delay_data	rx;
+};
+
+static struct clk_regmap_mux_data mmc_clkc_mux_data = {
+	.offset		= SD_EMMC_CLOCK,
+	.mask		= 0x3,
+	.shift		= 6,
+	.flags		= CLK_DIVIDER_ROUND_CLOSEST,
+};
+
+static struct clk_regmap_div_data mmc_clkc_div_data = {
+	.offset		= SD_EMMC_CLOCK,
+	.shift		= 0,
+	.width		= 6,
+	.flags		= CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
+};
+
+static struct meson_clk_phase_data mmc_clkc_core_phase = {
+	.ph = {
+		.reg_off	= SD_EMMC_CLOCK,
+		.shift	= 8,
+		.width	= 2,
+	}
+};
+
+static const struct mmc_clkc_data mmc_clkc_gx_data = {
+	.tx = {
+		.phase = {
+			.reg_off	= SD_EMMC_CLOCK,
+			.shift	= 10,
+			.width	= 2,
+		},
+		.delay = {
+			.reg_off	= SD_EMMC_CLOCK,
+			.shift	= 16,
+			.width	= 4,
+		},
+		.delay_step_ps	= CLK_DELAY_STEP_PS,
+	},
+	.rx = {
+		.phase = {
+			.reg_off	= SD_EMMC_CLOCK,
+			.shift	= 12,
+			.width	= 2,
+		},
+		.delay = {
+			.reg_off	= SD_EMMC_CLOCK,
+			.shift	= 20,
+			.width	= 4,
+		},
+		.delay_step_ps	= CLK_DELAY_STEP_PS,
+	},
+};
+
+static const struct mmc_clkc_data mmc_clkc_axg_data = {
+	.tx = {
+		.phase = {
+			.reg_off	= SD_EMMC_CLOCK,
+			.shift	= 10,
+			.width	= 2,
+		},
+		.delay = {
+			.reg_off	= SD_EMMC_CLOCK,
+			.shift	= 16,
+			.width	= 6,
+		},
+		.delay_step_ps	= CLK_DELAY_STEP_PS,
+	},
+	.rx = {
+		.phase = {
+			.reg_off	= SD_EMMC_CLOCK,
+			.shift	= 12,
+			.width	= 2,
+		},
+		.delay = {
+			.reg_off	= SD_EMMC_CLOCK,
+			.shift	= 22,
+			.width	= 6,
+		},
+		.delay_step_ps	= CLK_DELAY_STEP_PS,
+	},
+};
+
+static const struct of_device_id mmc_clkc_match_table[] = {
+	{
+		.compatible	= "amlogic,gx-mmc-clkc",
+		.data		= &mmc_clkc_gx_data
+	},
+	{
+		.compatible	= "amlogic,axg-mmc-clkc",
+		.data		= &mmc_clkc_axg_data
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, mmc_clkc_match_table);
+
+static struct clk_regmap *
+mmc_clkc_register_clk(struct device *dev, struct regmap *map,
+		      struct clk_init_data *init,
+		      const char *suffix, void *data)
+{
+	struct clk_regmap *clk;
+	char *name;
+	int ret;
+
+	clk = devm_kzalloc(dev, sizeof(*clk), GFP_KERNEL);
+	if (!clk)
+		return ERR_PTR(-ENOMEM);
+
+	name = kasprintf(GFP_KERNEL, "%s#%s", dev_name(dev), suffix);
+	if (!name)
+		return ERR_PTR(-ENOMEM);
+
+	init->name = name;
+
+	clk->map = map;
+	clk->data = data;
+	clk->hw.init = init;
+
+	ret = devm_clk_hw_register(dev, &clk->hw);
+	if (ret)
+		clk = ERR_PTR(ret);
+
+	kfree(name);
+	return clk;
+}
+
+static struct clk_regmap *mmc_clkc_register_mux(struct device *dev,
+						struct regmap *map)
+{
+	const char *parent_names[MUX_CLK_NUM_PARENTS];
+	struct clk_init_data init;
+	struct clk_regmap *mux;
+	struct clk *clk;
+	int i;
+
+	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
+		char name[8];
+
+		snprintf(name, sizeof(name), "clkin%d", i);
+		clk = devm_clk_get(dev, name);
+		if (IS_ERR(clk)) {
+			if (clk != ERR_PTR(-EPROBE_DEFER))
+				dev_err(dev, "Missing clock %s\n", name);
+			return ERR_PTR((long)clk);
+		}
+
+		parent_names[i] = __clk_get_name(clk);
+	}
+
+	init.ops = &clk_regmap_mux_ops;
+	init.flags = CLK_SET_RATE_PARENT;
+	init.parent_names = parent_names;
+	init.num_parents = MUX_CLK_NUM_PARENTS;
+
+	mux = mmc_clkc_register_clk(dev, map, &init, "mux", &mmc_clkc_mux_data);
+	if (IS_ERR(mux))
+		dev_err(dev, "Mux clock registration failed\n");
+
+	return mux;
+}
+
+static struct clk_regmap *
+mmc_clkc_register_clk_with_parent(struct device *dev, struct regmap *map,
+				  char *suffix, const char *parent,
+				  unsigned long flags,
+				  const struct clk_ops *ops, void *data)
+{
+	struct clk_init_data init;
+	struct clk_regmap *clk;
+
+	init.ops = ops;
+	init.flags = flags;
+	init.parent_names = (const char* const []){ parent, };
+	init.num_parents = 1;
+
+	clk = mmc_clkc_register_clk(dev, map, &init, suffix, data);
+	if (IS_ERR(clk))
+		dev_err(dev, "Core %s clock registration failed\n", suffix);
+
+	return clk;
+}
+
+static int mmc_clkc_probe(struct platform_device *pdev)
+{
+	struct clk_hw_onecell_data *onecell_data;
+	struct device *dev = &pdev->dev;
+	struct mmc_clkc_data *data;
+	struct regmap *map;
+	struct clk_regmap *mux, *div, *core, *rx, *tx;
+
+	data = (struct mmc_clkc_data *)of_device_get_match_data(dev);
+	if (!data)
+		return -ENODEV;
+
+	map = syscon_node_to_regmap(dev->of_node);
+	if (IS_ERR(map)) {
+		dev_err(dev, "could not find mmc clock controller\n");
+		return PTR_ERR(map);
+	}
+
+	onecell_data = devm_kzalloc(dev, sizeof(*onecell_data) +
+				    sizeof(*onecell_data->hws) * MMC_MAX_CLKS,
+				    GFP_KERNEL);
+	if (!onecell_data)
+		return -ENOMEM;
+
+	mux = mmc_clkc_register_mux(dev, map);
+	if (IS_ERR(mux))
+		return PTR_ERR(mux);
+
+	div = mmc_clkc_register_clk_with_parent(dev, map, "div",
+						clk_hw_get_name(&mux->hw),
+						CLK_SET_RATE_PARENT,
+						&clk_regmap_divider_with_init_ops,
+						&mmc_clkc_div_data);
+	if (IS_ERR(div))
+		return PTR_ERR(div);
+
+	core = mmc_clkc_register_clk_with_parent(dev, map, "core",
+						 clk_hw_get_name(&div->hw),
+						 CLK_SET_RATE_PARENT,
+						 &meson_clk_phase_ops,
+						 &mmc_clkc_core_phase);
+	if (IS_ERR(core))
+		return PTR_ERR(core);
+
+	rx = mmc_clkc_register_clk_with_parent(dev, map, "rx",
+					       clk_hw_get_name(&core->hw),  0,
+					       &meson_clk_phase_delay_ops,
+					       &data->rx);
+	if (IS_ERR(rx))
+		return PTR_ERR(rx);
+
+	tx = mmc_clkc_register_clk_with_parent(dev, map, "tx",
+					       clk_hw_get_name(&core->hw),  0,
+					       &meson_clk_phase_delay_ops,
+					       &data->tx);
+	if (IS_ERR(tx))
+		return PTR_ERR(tx);
+
+	onecell_data->hws[CLKID_MMC_MUX]		= &mux->hw,
+	onecell_data->hws[CLKID_MMC_DIV]		= &div->hw,
+	onecell_data->hws[CLKID_MMC_PHASE_CORE]		= &core->hw,
+	onecell_data->hws[CLKID_MMC_PHASE_RX]		= &rx->hw,
+	onecell_data->hws[CLKID_MMC_PHASE_TX]		= &tx->hw,
+	onecell_data->num				= MMC_MAX_CLKS;
+
+	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+					   onecell_data);
+}
+
+static struct platform_driver mmc_clkc_driver = {
+	.probe		= mmc_clkc_probe,
+	.driver		= {
+		.name	= "meson-mmc-clkc",
+		.of_match_table = of_match_ptr(mmc_clkc_match_table),
+	},
+};
+
+module_platform_driver(mmc_clkc_driver);
-- 
1.9.1