[PATCH 1/3] clk: meson: Add GXBB AO Clock and Reset controller driver

[Neil Armstrong <narmstrong@baylibre.com>]

Adds a Clock and Reset controller driver for the Always-On part
of the Amlogic Meson GXBB SoC.

It exports paired Clocks and Resets lines that will be used by
peripherals in the Always-On subsystem.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/clk/meson/Makefile     |   2 +-
 drivers/clk/meson/gxbb-aoclk.c | 203 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 204 insertions(+), 1 deletion(-)
 create mode 100644 drivers/clk/meson/gxbb-aoclk.c

diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
index 197e401..d4cd4a3 100644
--- a/drivers/clk/meson/Makefile
+++ b/drivers/clk/meson/Makefile
@@ -4,4 +4,4 @@
 
 obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-cpu.o clk-mpll.o
 obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b-clkc.o
-obj-$(CONFIG_COMMON_CLK_GXBB)	 += gxbb.o
+obj-$(CONFIG_COMMON_CLK_GXBB)	 += gxbb.o gxbb-aoclk.o
diff --git a/drivers/clk/meson/gxbb-aoclk.c b/drivers/clk/meson/gxbb-aoclk.c
new file mode 100644
index 0000000..56a9186
--- /dev/null
+++ b/drivers/clk/meson/gxbb-aoclk.c
@@ -0,0 +1,203 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ * The full GNU General Public License is included in this distribution
+ * in the file called COPYING.
+ *
+ * BSD LICENSE
+ *
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in
+ *     the documentation and/or other materials provided with the
+ *     distribution.
+ *   * Neither the name of Intel Corporation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/module.h>
+#include <dt-bindings/clock/gxbb-aoclkc.h>
+#include <dt-bindings/reset/gxbb-aoclkc.h>
+
+static DEFINE_SPINLOCK(clk_lock);
+
+struct gxbb_aoclk_reset_controller {
+	struct reset_controller_dev reset;
+	unsigned int *data;
+	void __iomem *base;
+};
+
+static int gxbb_aoclk_do_reset(struct reset_controller_dev *rcdev,
+			       unsigned long id)
+{
+	struct gxbb_aoclk_reset_controller *reset =
+		container_of(rcdev, struct gxbb_aoclk_reset_controller, reset);
+
+	writel(BIT(reset->data[id]), reset->base);
+
+	return 0;
+}
+
+static const struct reset_control_ops gxbb_aoclk_reset_ops = {
+	.reset = gxbb_aoclk_do_reset,
+};
+
+#define GXBB_AO_GATE(_name, _bit)					\
+static struct clk_gate _name##_ao = {					\
+	.reg = (void __iomem *)0,					\
+	.bit_idx = (_bit),						\
+	.lock = &clk_lock,						\
+	.hw.init = &(struct clk_init_data) {				\
+		.name = #_name "_ao",					\
+		.ops = &clk_gate_ops,					\
+		.parent_names = (const char *[]){ "clk81" },		\
+		.num_parents = 1,					\
+		.flags = (CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED),	\
+	},								\
+}
+
+GXBB_AO_GATE(remote, 0);
+GXBB_AO_GATE(i2c_master, 1);
+GXBB_AO_GATE(i2c_slave, 2);
+GXBB_AO_GATE(uart1, 3);
+GXBB_AO_GATE(uart2, 5);
+GXBB_AO_GATE(ir_blaster, 6);
+
+static unsigned int gxbb_aoclk_reset[] = {
+	[RESET_AO_REMOTE] = 16,
+	[RESET_AO_I2C_MASTER] = 18,
+	[RESET_AO_I2C_SLAVE] = 19,
+	[RESET_AO_UART1] = 17,
+	[RESET_AO_UART2] = 22,
+	[RESET_AO_IR_BLASTER] = 23,
+};
+
+static struct clk_gate *gxbb_aoclk_gate[] = {
+	[CLKID_AO_REMOTE] = &remote_ao,
+	[CLKID_AO_I2C_MASTER] = &i2c_master_ao,
+	[CLKID_AO_I2C_SLAVE] = &i2c_slave_ao,
+	[CLKID_AO_UART1] = &uart1_ao,
+	[CLKID_AO_UART2] = &uart2_ao,
+	[CLKID_AO_IR_BLASTER] = &ir_blaster_ao,
+};
+
+static struct clk_hw_onecell_data gxbb_aoclk_onecell_data = {
+	.hws = {
+		[CLKID_AO_REMOTE] = &remote_ao.hw,
+		[CLKID_AO_I2C_MASTER] = &i2c_master_ao.hw,
+		[CLKID_AO_I2C_SLAVE] = &i2c_slave_ao.hw,
+		[CLKID_AO_UART1] = &uart1_ao.hw,
+		[CLKID_AO_UART2] = &uart2_ao.hw,
+		[CLKID_AO_IR_BLASTER] = &ir_blaster_ao.hw,
+	},
+	.num = ARRAY_SIZE(gxbb_aoclk_gate),
+};
+
+static int gxbb_aoclkc_probe(struct platform_device *pdev)
+{
+	void __iomem *base;
+	int ret, clkid;
+	struct device *dev = &pdev->dev;
+	struct gxbb_aoclk_reset_controller *rstc;
+
+	rstc = devm_kzalloc(dev, sizeof(rstc), GFP_KERNEL);
+	if (!rstc)
+		return -ENOMEM;
+
+	/*  Generic clocks */
+	base = of_iomap(dev->of_node, 0);
+	if (!base) {
+		pr_err("%s: Unable to map clk base\n", __func__);
+		return -ENXIO;
+	}
+
+	/* Reset Controller */
+	rstc->base = base;
+	rstc->data = gxbb_aoclk_reset;
+	rstc->reset.ops = &gxbb_aoclk_reset_ops;
+	rstc->reset.nr_resets = ARRAY_SIZE(gxbb_aoclk_reset);
+	rstc->reset.of_node = dev->of_node;
+	ret = devm_reset_controller_register(dev, &rstc->reset);
+
+	/*
+	 * Populate base address and register all clks
+	 */
+	for (clkid = 0; clkid < gxbb_aoclk_onecell_data.num; clkid++) {
+		gxbb_aoclk_gate[clkid]->reg = base;
+
+		ret = devm_clk_hw_register(dev,
+					gxbb_aoclk_onecell_data.hws[clkid]);
+		if (ret)
+			goto iounmap;
+	}
+
+	return of_clk_add_hw_provider(dev->of_node, of_clk_hw_onecell_get,
+			&gxbb_aoclk_onecell_data);
+
+iounmap:
+	iounmap(base);
+	return ret;
+}
+
+static const struct of_device_id gxbb_aoclkc_match_table[] = {
+	{ .compatible = "amlogic,gxbb-aoclkc" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, gxbb_aoclkc_match_table);
+
+static struct platform_driver gxbb_aoclkc_driver = {
+	.probe		= gxbb_aoclkc_probe,
+	.driver		= {
+		.name	= "gxbb-aoclkc",
+		.of_match_table = gxbb_aoclkc_match_table,
+	},
+};
+
+module_platform_driver(gxbb_aoclkc_driver);
+
+MODULE_DESCRIPTION("AmLogic Meson GXBB AO Clock Controller Driver");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("platform:gxbb-aoclkc");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
-- 
2.7.0