[PATCH v4 2/3] clk: meson: add a driver for the Meson8/8b/8m2 SDHC clock controller

[Martin Blumenstingl]

The SDHC (MMC) controller embeds a clock controller inside one of the
SDHC registers. The outputs of thisclock controller are dedicated to the
SDHC controller.

Implement a dedicated clock controller driver so we can keep all the
clock specific logic outside of the MMC controller driver. There is no
dedicated clock controller OF node because the hardware is a big SDHC IP
block with an embedded clock controller (so the .dts doesn't need a
separate clock controller node). Instead this driver re-uses the regmap
as registered by the (platform_device) parent.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
---
 drivers/clk/meson/Kconfig         |   9 ++
 drivers/clk/meson/Makefile        |   1 +
 drivers/clk/meson/meson-mx-sdhc.c | 212 ++++++++++++++++++++++++++++++
 3 files changed, 222 insertions(+)
 create mode 100644 drivers/clk/meson/meson-mx-sdhc.c

diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
index dabeb435d067..8769335d2d46 100644
--- a/drivers/clk/meson/Kconfig
+++ b/drivers/clk/meson/Kconfig
@@ -53,6 +53,15 @@ config COMMON_CLK_MESON8B
 	  S805 (Meson8b) and S812 (Meson8m2) devices. Say Y if you
 	  want peripherals and CPU frequency scaling to work.
 
+config COMMON_CLK_MESON_MX_SDHC
+	tristate "Meson MX SDHC MMC Clock Controller Driver"
+	depends on ARCH_MESON
+	select COMMON_CLK_MESON_REGMAP
+	help
+	  Support for the SDHC clock controller on Amlogic Meson8/8b/8m2 SoCs
+	  devices. Say Y or M if you want to use the SDHC MMC controller.
+	  Otherwise say N.
+
 config COMMON_CLK_GXBB
 	bool
 	depends on ARCH_MESON
diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
index 6eca2a406ee3..b71c7ae78dbd 100644
--- a/drivers/clk/meson/Makefile
+++ b/drivers/clk/meson/Makefile
@@ -19,3 +19,4 @@ obj-$(CONFIG_COMMON_CLK_AXG_AUDIO) += axg-audio.o
 obj-$(CONFIG_COMMON_CLK_GXBB) += gxbb.o gxbb-aoclk.o
 obj-$(CONFIG_COMMON_CLK_G12A) += g12a.o g12a-aoclk.o
 obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o meson8-ddr.o
+obj-$(CONFIG_COMMON_CLK_MESON_MX_SDHC) += meson-mx-sdhc.o
diff --git a/drivers/clk/meson/meson-mx-sdhc.c b/drivers/clk/meson/meson-mx-sdhc.c
new file mode 100644
index 000000000000..b98a35d99f65
--- /dev/null
+++ b/drivers/clk/meson/meson-mx-sdhc.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Amlogic Meson SDHC clock controller
+ *
+ * Copyright (C) 2019 Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
+ */
+
+#include <dt-bindings/clock/meson-mx-sdhc-clkc.h>
+
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "clk-regmap.h"
+#include "clk-pll.h"
+
+#define MESON_SDHC_CLKC			0x10
+
+static const struct clk_regmap meson_mx_sdhc_src_sel = {
+	.data = &(struct clk_regmap_mux_data){
+		.offset = MESON_SDHC_CLKC,
+		.mask = 0x3,
+		.shift = 16,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_src_sel",
+		.ops = &clk_regmap_mux_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .fw_name = "clkin0", .index = -1, },
+			{ .fw_name = "clkin1", .index = -1, },
+			{ .fw_name = "clkin2", .index = -1, },
+			{ .fw_name = "clkin3", .index = -1, },
+		},
+		.num_parents = 4,
+	},
+};
+
+static const struct clk_div_table meson_mx_sdhc_div_table[] = {
+	{ .div = 6, .val = 5, },
+	{ .div = 8, .val = 7, },
+	{ .div = 9, .val = 8, },
+	{ .div = 10, .val = 9, },
+	{ .div = 12, .val = 11, },
+	{ .div = 16, .val = 15, },
+	{ .div = 18, .val = 17, },
+	{ .div = 34, .val = 33, },
+	{ .div = 142, .val = 141, },
+	{ .div = 850, .val = 849, },
+	{ .div = 2126, .val = 2125, },
+	{ .div = 4096, .val = 4095, },
+	{ /* sentinel */ }
+};
+
+static const struct clk_regmap meson_mx_sdhc_div = {
+	.data = &(struct clk_regmap_div_data){
+		.offset = MESON_SDHC_CLKC,
+		.shift = 0,
+		.width = 12,
+		.table = meson_mx_sdhc_div_table,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_div",
+		.ops = &clk_regmap_divider_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .name = "sdhc_src_sel", .index = -1, },
+		},
+		.num_parents = 1,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static const struct clk_regmap meson_mx_sdhc_mod_clk_en = {
+	.data = &(struct clk_regmap_gate_data){
+		.offset = MESON_SDHC_CLKC,
+		.bit_idx = 15,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_mod_clk_on",
+		.ops = &clk_regmap_gate_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .name = "sdhc_div", .index = -1, },
+		},
+		.num_parents = 1,
+		.flags = CLK_SET_RATE_GATE,
+	},
+};
+
+static const struct clk_regmap meson_mx_sdhc_tx_clk_en = {
+	.data = &(struct clk_regmap_gate_data){
+		.offset = MESON_SDHC_CLKC,
+		.bit_idx = 14,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_tx_clk_on",
+		.ops = &clk_regmap_gate_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .name = "sdhc_div", .index = -1, },
+		},
+		.num_parents = 1,
+		.flags = CLK_SET_RATE_GATE,
+	},
+};
+
+static const struct clk_regmap meson_mx_sdhc_rx_clk_en = {
+	.data = &(struct clk_regmap_gate_data){
+		.offset = MESON_SDHC_CLKC,
+		.bit_idx = 13,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_rx_clk_on",
+		.ops = &clk_regmap_gate_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .name = "sdhc_div", .index = -1, },
+		},
+		.num_parents = 1,
+		.flags = CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
+	},
+};
+
+static const struct clk_regmap meson_mx_sdhc_sd_clk_en = {
+	.data = &(struct clk_regmap_gate_data){
+		.offset = MESON_SDHC_CLKC,
+		.bit_idx = 12,
+	},
+	.hw.init = &(struct clk_init_data){
+		.name = "sdhc_sd_clk_on",
+		.ops = &clk_regmap_gate_ops,
+		.parent_data = (const struct clk_parent_data[]) {
+			{ .name = "sdhc_div", .index = -1, },
+		},
+		.num_parents = 1,
+		.flags = CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
+	},
+};
+
+static const struct clk_regmap *meson_mx_sdhc_clk_regmaps[] = {
+	[SDHC_CLKID_SRC_SEL]	= &meson_mx_sdhc_src_sel,
+	[SDHC_CLKID_DIV]	= &meson_mx_sdhc_div,
+	[SDHC_CLKID_MOD_CLK]	= &meson_mx_sdhc_mod_clk_en,
+	[SDHC_CLKID_SD_CLK]	= &meson_mx_sdhc_sd_clk_en,
+	[SDHC_CLKID_TX_CLK]	= &meson_mx_sdhc_tx_clk_en,
+	[SDHC_CLKID_RX_CLK]	= &meson_mx_sdhc_rx_clk_en,
+};
+
+#define MESON_MX_SDHC_NUM_CLKS ARRAY_SIZE(meson_mx_sdhc_clk_regmaps)
+
+static int meson_mx_sdhc_clkc_probe(struct platform_device *pdev)
+{
+	struct device *parent = pdev->dev.parent;
+	struct clk_hw_onecell_data *onecell_data;
+	struct clk_regmap *clk_regmap;
+	struct regmap *regmap;
+	int i, ret;
+
+	regmap = dev_get_regmap(parent, NULL);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	clk_regmap = devm_kcalloc(parent, sizeof(*clk_regmap),
+				  MESON_MX_SDHC_NUM_CLKS, GFP_KERNEL);
+	if (!clk_regmap)
+		return -ENOMEM;
+
+	onecell_data = devm_kzalloc(parent,
+				    struct_size(onecell_data, hws,
+						MESON_MX_SDHC_NUM_CLKS),
+				    GFP_KERNEL);
+	if (!onecell_data)
+		return -ENOMEM;
+
+	for (i = 0; i < MESON_MX_SDHC_NUM_CLKS; i++) {
+		memcpy(&clk_regmap[i], meson_mx_sdhc_clk_regmaps[i],
+		       sizeof(*clk_regmap));
+
+		clk_regmap[i].map = regmap;
+		onecell_data->hws[i] = &clk_regmap[i].hw;
+
+		ret = devm_clk_hw_register(parent, onecell_data->hws[i]);
+		if (ret) {
+			dev_err(parent,
+				"Registration of SDHC clock %d failed\n", i);
+			return ret;
+		}
+	}
+
+	onecell_data->num = MESON_MX_SDHC_NUM_CLKS;
+
+	return devm_of_clk_add_hw_provider(parent, of_clk_hw_onecell_get,
+					   onecell_data);
+}
+
+static const struct platform_device_id meson_mx_sdhc_clkc_ids[] = {
+	{ "meson8-sdhc-clkc" },
+	{ "meson8b-sdhc-clkc" },
+	{ "meson8m2-sdhc-clkc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, meson_mx_sdhc_clkc_ids);
+
+static struct platform_driver meson_mx_sdhc_clkc_driver = {
+	.id_table	= meson_mx_sdhc_clkc_ids,
+	.probe		= meson_mx_sdhc_clkc_probe,
+	.driver		= {
+		.name	= "meson-mx-sdhc-clkc",
+	},
+};
+module_platform_driver(meson_mx_sdhc_clkc_driver);
+
+MODULE_DESCRIPTION("Amlogic Meson8/8b/8m2 SDHC clock controller driver");
+MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
-- 
2.24.1