[PATCH 1/2] clk: hisilicon: add stub clock driver for Hi3660

[Zhong Kaihua]

From: Kaihua Zhong <zhongkaihua@xxxxxxxxxx>

Add stub clock driver for Hi3660, this patch registers clock node for
big and LITTLE clusters and GPU clock. For DDR clock, it's should
partially supported but has not been verified yet.

Signed-off-by: Kai Zhao <zhaokai1@xxxxxxxxxxxxx>
Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
Signed-off-by: Tao Wang <kevin.wangtao@xxxxxxxxxxxxx>
Signed-off-by: Ruyi Wang <wangruyi@xxxxxxxxxx>
Tested-by: Kaihua Zhong <zhongkaihua@xxxxxxxxxx>
---
 drivers/clk/hisilicon/Kconfig            |   6 +
 drivers/clk/hisilicon/Makefile           |   1 +
 drivers/clk/hisilicon/clk-hi3660-stub.c  | 247 +++++++++++++++++++++++++++++++
 include/dt-bindings/clock/hi3660-clock.h |   7 +
 4 files changed, 261 insertions(+)
 create mode 100755 drivers/clk/hisilicon/clk-hi3660-stub.c

diff --git a/drivers/clk/hisilicon/Kconfig b/drivers/clk/hisilicon/Kconfig
index 7098bfd..1bd4355 100644
--- a/drivers/clk/hisilicon/Kconfig
+++ b/drivers/clk/hisilicon/Kconfig
@@ -49,3 +49,9 @@ config STUB_CLK_HI6220
 	default ARCH_HISI
 	help
 	  Build the Hisilicon Hi6220 stub clock driver.
+
+config STUB_CLK_HI3660
+	bool "Hi3660 Stub Clock Driver"
+	depends on COMMON_CLK_HI3660 && MAILBOX
+	help
+	  Build the Hisilicon Hi3660 stub clock driver.
diff --git a/drivers/clk/hisilicon/Makefile b/drivers/clk/hisilicon/Makefile
index 1e4c3dd..0a5b499 100644
--- a/drivers/clk/hisilicon/Makefile
+++ b/drivers/clk/hisilicon/Makefile
@@ -14,3 +14,4 @@ obj-$(CONFIG_COMMON_CLK_HI3798CV200)	+= crg-hi3798cv200.o
 obj-$(CONFIG_COMMON_CLK_HI6220)	+= clk-hi6220.o
 obj-$(CONFIG_RESET_HISI)	+= reset.o
 obj-$(CONFIG_STUB_CLK_HI6220)	+= clk-hi6220-stub.o
+obj-$(CONFIG_STUB_CLK_HI3660)	+= clk-hi3660-stub.o
diff --git a/drivers/clk/hisilicon/clk-hi3660-stub.c b/drivers/clk/hisilicon/clk-hi3660-stub.c
new file mode 100755
index 0000000..5a04390
--- /dev/null
+++ b/drivers/clk/hisilicon/clk-hi3660-stub.c
@@ -0,0 +1,247 @@
+/*
+ * Hisilicon clock driver
+ *
+ * Copyright (c) 2013-2015 Hisilicon Limited.
+ * Copyright (c) 2017 Linaro Limited.
+ * Copyright (c) 2017 Hisilicon Limited.
+ *
+ * Author: Kai Zhao <zhaokai1@xxxxxxxxxxxxx>
+ * Author: Leo Yan <leo.yan@xxxxxxxxxx>
+ * Author: Tao Wang <kevin.wangtao@xxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/clkdev.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/mailbox_client.h>
+#include <dt-bindings/clock/hi3660-clock.h>
+
+#define FREQ_DATA_OFFSET	0x70
+#define MHZ			1000000
+
+struct hi3660_stub_clk_chan {
+	struct mbox_client cl;
+	struct mbox_chan *mbox;
+};
+
+struct hi3660_stub_clk {
+	unsigned int id;
+	struct device *dev;
+	struct clk_hw hw;
+	const char *clk_name;
+	unsigned int set_rate_cmd;
+	unsigned int msg[8];
+	unsigned int rate;
+};
+
+static void __iomem *freq_reg;
+static struct hi3660_stub_clk_chan *chan;
+
+static struct hi3660_stub_clk hisi_stub_clk[HI3660_CLK_STUB_NUM] = {
+	[HI3660_CLK_STUB_CLUSTER0] = {
+		.id = HI3660_CLK_STUB_CLUSTER0,
+		.clk_name = "cpu-cluster.0",
+		.set_rate_cmd = 0x0001030A,
+	},
+	[HI3660_CLK_STUB_CLUSTER1] = {
+		.id = HI3660_CLK_STUB_CLUSTER1,
+		.clk_name = "cpu-cluster.1",
+		.set_rate_cmd = 0x0002030A,
+	},
+	[HI3660_CLK_STUB_GPU] = {
+		.id = HI3660_CLK_STUB_GPU,
+		.clk_name = "clk-g3d",
+		.set_rate_cmd = 0x0003030A,
+	},
+	[HI3660_CLK_STUB_DDR] = {
+		.id = HI3660_CLK_STUB_DDR,
+		.clk_name = "clk-ddrc",
+		.set_rate_cmd = 0x00040309,
+	},
+};
+
+static unsigned long hi3660_stub_clk_recalc_rate(
+		struct clk_hw *hw, unsigned long parent_rate)
+{
+	struct hi3660_stub_clk *stub_clk =
+		container_of(hw, struct hi3660_stub_clk, hw);
+
+	if (stub_clk->id < HI3660_CLK_STUB_NUM)
+		stub_clk->rate = readl(freq_reg + (stub_clk->id << 2)) * MHZ;
+
+	pr_debug("get rate%d;%u\n", stub_clk->id, stub_clk->rate);
+
+	return stub_clk->rate;
+}
+
+static long hi3660_stub_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+				       unsigned long *prate)
+{
+	return rate;
+}
+
+int hi3660_stub_clk_determine_rate(struct clk_hw *hw,
+				   struct clk_rate_request *req)
+{
+	pr_debug("%s: enter %ld\n", __func__, req->rate);
+	return 0;
+}
+
+static int hi3660_stub_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+				    unsigned long parent_rate)
+{
+	struct hi3660_stub_clk *stub_clk =
+		container_of(hw, struct hi3660_stub_clk, hw);
+
+	if (stub_clk->id < HI3660_CLK_STUB_NUM) {
+		stub_clk->msg[0] = stub_clk->set_rate_cmd;
+		stub_clk->msg[1] = rate / MHZ;
+
+		pr_debug("%s: set_rate_cmd[0] %x [1] %x\n", __func__,
+				stub_clk->msg[0], stub_clk->msg[1]);
+
+		mbox_send_message(chan->mbox, stub_clk->msg);
+	}
+
+	stub_clk->rate = rate;
+	return 0;
+}
+
+static struct clk_ops hi3660_stub_clk_ops = {
+	.recalc_rate    = hi3660_stub_clk_recalc_rate,
+	.determine_rate = hi3660_stub_clk_determine_rate,
+	.round_rate     = hi3660_stub_clk_round_rate,
+	.set_rate       = hi3660_stub_clk_set_rate,
+};
+
+static struct clk *hi3660_register_stub_clk(struct device *dev,
+		struct hi3660_stub_clk *stub_clk)
+{
+	struct clk_init_data init = {};
+	struct clk *clk;
+
+	stub_clk->hw.init = &init;
+	stub_clk->dev = dev;
+
+	init.name = stub_clk->clk_name;
+	init.ops = &hi3660_stub_clk_ops;
+	init.num_parents = 0;
+	init.flags = CLK_GET_RATE_NOCACHE;
+
+	clk = devm_clk_register(dev, &stub_clk->hw);
+	if (!IS_ERR(clk))
+		dev_dbg(dev, "Registered clock '%s'\n", init.name);
+
+	return clk;
+}
+
+static int hi3660_stub_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = pdev->dev.of_node;
+	struct clk_onecell_data	*data;
+	struct resource *res;
+	struct clk **clk_table;
+	struct clk *clk;
+	unsigned int idx;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		dev_err(dev, "could not allocate clock data\n");
+		return -ENOMEM;
+	}
+
+	clk_table = devm_kzalloc(dev,
+		sizeof(*clk_table) * HI3660_CLK_STUB_NUM, GFP_KERNEL);
+	if (!clk_table) {
+		dev_err(dev, "could not allocate clock lookup table\n");
+		return -ENOMEM;
+	}
+	data->clks = clk_table;
+	data->clk_num = HI3660_CLK_STUB_NUM;
+
+	chan = devm_kzalloc(dev, sizeof(*chan), GFP_KERNEL);
+	if (!chan) {
+		dev_err(dev, "failed to allocate memory for mbox\n");
+		return -ENOMEM;
+	}
+
+	/* Use mailbox client with blocking mode */
+	chan->cl.dev = dev;
+	chan->cl.tx_done = NULL;
+	chan->cl.tx_block = false;
+	chan->cl.tx_tout = 500;
+	chan->cl.knows_txdone = false;
+
+	/* Allocate mailbox channel */
+	chan->mbox = mbox_request_channel(&chan->cl, 0);
+	if (IS_ERR(chan->mbox)) {
+		dev_err(dev, "failed get mailbox channel\n");
+		return PTR_ERR(chan->mbox);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	freq_reg = devm_ioremap(dev, res->start, resource_size(res));
+	if (IS_ERR(freq_reg)) {
+		dev_err(dev, "failed get shared memory\n");
+		return -ENOMEM;
+	}
+	freq_reg += FREQ_DATA_OFFSET;
+
+	for (idx = 0; idx < HI3660_CLK_STUB_NUM; idx++) {
+		clk = hi3660_register_stub_clk(dev, &hisi_stub_clk[idx]);
+		if (IS_ERR(clk))
+			return PTR_ERR(clk);
+
+		data->clks[idx] = clk;
+	}
+	of_clk_add_provider(np, of_clk_src_onecell_get, data);
+
+	return 0;
+}
+
+static const struct of_device_id hi3660_stub_clk_of_match[] = {
+	{ .compatible = "hisilicon,hi3660-stub-clk", },
+	{}
+};
+
+static struct platform_driver hi3660_stub_clk_driver = {
+	.driver = {
+		.name = "hi3660-stub-clk",
+		.of_match_table = hi3660_stub_clk_of_match,
+	},
+	.probe = hi3660_stub_clk_probe,
+};
+
+static int __init hi3660_stub_clk_init(void)
+{
+	return platform_driver_register(&hi3660_stub_clk_driver);
+}
+subsys_initcall(hi3660_stub_clk_init);
diff --git a/include/dt-bindings/clock/hi3660-clock.h b/include/dt-bindings/clock/hi3660-clock.h
index 1c00b7f..4018eb2 100644
--- a/include/dt-bindings/clock/hi3660-clock.h
+++ b/include/dt-bindings/clock/hi3660-clock.h
@@ -191,4 +191,11 @@
 #define HI3660_CLK_I2C6_IOMCU		3
 #define HI3660_CLK_IOMCU_PERI0		4
 
+/* clk in stub clock */
+#define HI3660_CLK_STUB_CLUSTER0	0
+#define HI3660_CLK_STUB_CLUSTER1	1
+#define HI3660_CLK_STUB_GPU		2
+#define HI3660_CLK_STUB_DDR		3
+#define HI3660_CLK_STUB_NUM		4
+
 #endif	/* __DTS_HI3660_CLOCK_H */
-- 
1.8.3.2