clk: Add Oxford Semiconductor OXNAS Standard Clocks

Add Oxford Semiconductor OXNAS SoC Family Standard Clocks support.

Signed-off-by: Neil Armstrong <[e-mail]>
[[e-mail]: Drop NULL/continue check in registration
loop]
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/Kconfig

···
 	---help---
 	  Support for the Marvell PXA SoC.
 
+config COMMON_CLK_OXNAS
+	bool "Clock driver for the OXNAS SoC Family"
+	select MFD_SYSCON
+	---help---
+	  Support for the OXNAS SoC Family clocks.
+
 source "drivers/clk/bcm/Kconfig"
 source "drivers/clk/hisilicon/Kconfig"
 source "drivers/clk/mvebu/Kconfig"

drivers/clk/Makefile

···
 obj-$(CONFIG_ARCH_MOXART)		+= clk-moxart.o
 obj-$(CONFIG_ARCH_NOMADIK)		+= clk-nomadik.o
 obj-$(CONFIG_ARCH_NSPIRE)		+= clk-nspire.o
+obj-$(CONFIG_COMMON_CLK_OXNAS)		+= clk-oxnas.o
 obj-$(CONFIG_COMMON_CLK_PALMAS)		+= clk-palmas.o
 obj-$(CONFIG_CLK_QORIQ)			+= clk-qoriq.o
 obj-$(CONFIG_COMMON_CLK_RK808)		+= clk-rk808.o

drivers/clk/clk-oxnas.c

···
+/*
+ * Copyright (C) 2010 Broadcom
+ * Copyright (C) 2012 Stephen Warren
+ * Copyright (C) 2016 Neil Armstrong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/stringify.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+/* Standard regmap gate clocks */
+struct clk_oxnas {
+	struct clk_hw hw;
+	signed char bit;
+	struct regmap *regmap;
+};
+
+/* Regmap offsets */
+#define CLK_STAT_REGOFFSET	0x24
+#define CLK_SET_REGOFFSET	0x2c
+#define CLK_CLR_REGOFFSET	0x30
+
+static inline struct clk_oxnas *to_clk_oxnas(struct clk_hw *hw)
+{
+	return container_of(hw, struct clk_oxnas, hw);
+}
+
+static int oxnas_clk_is_enabled(struct clk_hw *hw)
+{
+	struct clk_oxnas *std = to_clk_oxnas(hw);
+	int ret;
+	unsigned int val;
+
+	ret = regmap_read(std->regmap, CLK_STAT_REGOFFSET, &val);
+	if (ret < 0)
+		return ret;
+
+	return val & BIT(std->bit);
+}
+
+static int oxnas_clk_enable(struct clk_hw *hw)
+{
+	struct clk_oxnas *std = to_clk_oxnas(hw);
+
+	regmap_write(std->regmap, CLK_SET_REGOFFSET, BIT(std->bit));
+
+	return 0;
+}
+
+static void oxnas_clk_disable(struct clk_hw *hw)
+{
+	struct clk_oxnas *std = to_clk_oxnas(hw);
+
+	regmap_write(std->regmap, CLK_CLR_REGOFFSET, BIT(std->bit));
+}
+
+static const struct clk_ops oxnas_clk_ops = {
+	.enable = oxnas_clk_enable,
+	.disable = oxnas_clk_disable,
+	.is_enabled = oxnas_clk_is_enabled,
+};
+
+static const char *const oxnas_clk_parents[] = {
+	"oscillator",
+};
+
+static const char *const eth_parents[] = {
+	"gmacclk",
+};
+
+#define DECLARE_STD_CLKP(__clk, __parent)			\
+static const struct clk_init_data clk_##__clk##_init = {	\
+	.name = __stringify(__clk),				\
+	.ops = &oxnas_clk_ops,					\
+	.parent_names = __parent,				\
+	.num_parents = ARRAY_SIZE(__parent),			\
+}
+
+#define DECLARE_STD_CLK(__clk) DECLARE_STD_CLKP(__clk, oxnas_clk_parents)
+
+/* Hardware Bit - Clock association */
+struct clk_oxnas_init_data {
+	unsigned long bit;
+	const struct clk_init_data *clk_init;
+};
+
+/* Clk init data declaration */
+DECLARE_STD_CLK(leon);
+DECLARE_STD_CLK(dma_sgdma);
+DECLARE_STD_CLK(cipher);
+DECLARE_STD_CLK(sata);
+DECLARE_STD_CLK(audio);
+DECLARE_STD_CLK(usbmph);
+DECLARE_STD_CLKP(etha, eth_parents);
+DECLARE_STD_CLK(pciea);
+DECLARE_STD_CLK(nand);
+
+/* Table index is clock indice */
+static const struct clk_oxnas_init_data clk_oxnas_init[] = {
+	[0] = {0, &clk_leon_init},
+	[1] = {1, &clk_dma_sgdma_init},
+	[2] = {2, &clk_cipher_init},
+	/* Skip & Do not touch to DDR clock */
+	[3] = {4, &clk_sata_init},
+	[4] = {5, &clk_audio_init},
+	[5] = {6, &clk_usbmph_init},
+	[6] = {7, &clk_etha_init},
+	[7] = {8, &clk_pciea_init},
+	[8] = {9, &clk_nand_init},
+};
+
+struct clk_oxnas_data {
+	struct clk_oxnas clk_oxnas[ARRAY_SIZE(clk_oxnas_init)];
+	struct clk_onecell_data onecell_data[ARRAY_SIZE(clk_oxnas_init)];
+	struct clk *clks[ARRAY_SIZE(clk_oxnas_init)];
+};
+
+static int oxnas_stdclk_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct clk_oxnas_data *clk_oxnas;
+	struct regmap *regmap;
+	int i;
+
+	clk_oxnas = devm_kzalloc(&pdev->dev, sizeof(*clk_oxnas), GFP_KERNEL);
+	if (!clk_oxnas)
+		return -ENOMEM;
+
+	regmap = syscon_node_to_regmap(of_get_parent(np));
+	if (!regmap) {
+		dev_err(&pdev->dev, "failed to have parent regmap\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(clk_oxnas_init); i++) {
+		struct clk_oxnas *_clk;
+
+		_clk = &clk_oxnas->clk_oxnas[i];
+		_clk->bit = clk_oxnas_init[i].bit;
+		_clk->hw.init = clk_oxnas_init[i].clk_init;
+		_clk->regmap = regmap;
+
+		clk_oxnas->clks[i] =
+			devm_clk_register(&pdev->dev, &_clk->hw);
+		if (WARN_ON(IS_ERR(clk_oxnas->clks[i])))
+			return PTR_ERR(clk_oxnas->clks[i]);
+	}
+
+	clk_oxnas->onecell_data->clks = clk_oxnas->clks;
+	clk_oxnas->onecell_data->clk_num = ARRAY_SIZE(clk_oxnas_init);
+
+	return of_clk_add_provider(np, of_clk_src_onecell_get,
+				   clk_oxnas->onecell_data);
+}
+
+static int oxnas_stdclk_remove(struct platform_device *pdev)
+{
+	of_clk_del_provider(pdev->dev.of_node);
+
+	return 0;
+}
+
+static const struct of_device_id oxnas_stdclk_dt_ids[] = {
+	{ .compatible = "oxsemi,ox810se-stdclk" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, oxnas_stdclk_dt_ids);
+
+static struct platform_driver oxnas_stdclk_driver = {
+	.probe = oxnas_stdclk_probe,
+	.remove = oxnas_stdclk_remove,
+	.driver	= {
+		.name = "oxnas-stdclk",
+		.of_match_table = oxnas_stdclk_dt_ids,
+	},
+};
+
+module_platform_driver(oxnas_stdclk_driver);