Merge branch 'clk-hi3660-stub' into clk-next

* clk-hi3660-stub:
  clk: hisilicon: Add support for Hi3660 stub clocks
  dt-bindings: clk: Hi3660: Document stub clock

Documentation/devicetree/bindings/clock/hi3660-clock.txt

@@ -13,12 +13,18 @@ Required Properties:
 	- "hisilicon,hi3660-pmuctrl"
 	- "hisilicon,hi3660-sctrl"
 	- "hisilicon,hi3660-iomcu"
+	- "hisilicon,hi3660-stub-clk"
 
 - reg: physical base address of the controller and length of memory mapped
   region.
 
 - #clock-cells: should be 1.
 
+Optional Properties:
+
+- mboxes: Phandle to the mailbox for sending message to MCU.
+            (See: ../mailbox/hisilicon,hi3660-mailbox.txt for more info)
+
 Each clock is assigned an identifier and client nodes use this identifier
 to specify the clock which they consume.
 

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.

drivers/clk/hisilicon/Makefile

@@ -15,3 +15,4 @@ 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

drivers/clk/hisilicon/clk-hi3660-stub.c

+/*
+ * Hisilicon clock driver
+ *
+ * Copyright (c) 2013-2017 Hisilicon Limited.
+ * Copyright (c) 2017 Linaro Limited.
+ *
+ * Author: Kai Zhao <zhaokai1@hisilicon.com>
+ *	    Tao Wang <kevin.wangtao@hisilicon.com>
+ *	    Leo Yan <leo.yan@linaro.org>
+ *
+ * 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.
+ *
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <dt-bindings/clock/hi3660-clock.h>
+
+#define HI3660_STUB_CLOCK_DATA		(0x70)
+#define MHZ				(1000 * 1000)
+
+#define DEFINE_CLK_STUB(_id, _cmd, _name)			\
+	{							\
+		.id = (_id),					\
+		.cmd = (_cmd),					\
+		.hw.init = &(struct clk_init_data) {		\
+			.name = #_name,				\
+			.ops = &hi3660_stub_clk_ops,		\
+			.num_parents = 0,			\
+			.flags = CLK_GET_RATE_NOCACHE,		\
+		},						\
+	},
+
+#define to_stub_clk(_hw) container_of(_hw, struct hi3660_stub_clk, hw)
+
+struct hi3660_stub_clk_chan {
+	struct mbox_client cl;
+	struct mbox_chan *mbox;
+};
+
+struct hi3660_stub_clk {
+	unsigned int id;
+	struct clk_hw hw;
+	unsigned int cmd;
+	unsigned int msg[8];
+	unsigned int rate;
+};
+
+static void __iomem *freq_reg;
+static struct hi3660_stub_clk_chan stub_clk_chan;
+
+static unsigned long hi3660_stub_clk_recalc_rate(struct clk_hw *hw,
+						 unsigned long parent_rate)
+{
+	struct hi3660_stub_clk *stub_clk = to_stub_clk(hw);
+
+	/*
+	 * LPM3 writes back the CPU frequency in shared SRAM so read
+	 * back the frequency.
+	 */
+	stub_clk->rate = readl(freq_reg + (stub_clk->id << 2)) * MHZ;
+	return stub_clk->rate;
+}
+
+static long hi3660_stub_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+				       unsigned long *prate)
+{
+	/*
+	 * LPM3 handles rate rounding so just return whatever
+	 * rate is requested.
+	 */
+	return rate;
+}
+
+static int hi3660_stub_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+				    unsigned long parent_rate)
+{
+	struct hi3660_stub_clk *stub_clk = to_stub_clk(hw);
+
+	stub_clk->msg[0] = stub_clk->cmd;
+	stub_clk->msg[1] = rate / MHZ;
+
+	dev_dbg(stub_clk_chan.cl.dev, "set rate msg[0]=0x%x msg[1]=0x%x\n",
+		stub_clk->msg[0], stub_clk->msg[1]);
+
+	mbox_send_message(stub_clk_chan.mbox, stub_clk->msg);
+	mbox_client_txdone(stub_clk_chan.mbox, 0);
+
+	stub_clk->rate = rate;
+	return 0;
+}
+
+static const struct clk_ops hi3660_stub_clk_ops = {
+	.recalc_rate    = hi3660_stub_clk_recalc_rate,
+	.round_rate     = hi3660_stub_clk_round_rate,
+	.set_rate       = hi3660_stub_clk_set_rate,
+};
+
+static struct hi3660_stub_clk hi3660_stub_clks[HI3660_CLK_STUB_NUM] = {
+	DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER0, 0x0001030A, "cpu-cluster.0")
+	DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER1, 0x0002030A, "cpu-cluster.1")
+	DEFINE_CLK_STUB(HI3660_CLK_STUB_GPU, 0x0003030A, "clk-g3d")
+	DEFINE_CLK_STUB(HI3660_CLK_STUB_DDR, 0x00040309, "clk-ddrc")
+};
+
+static struct clk_hw *hi3660_stub_clk_hw_get(struct of_phandle_args *clkspec,
+					     void *data)
+{
+	unsigned int idx = clkspec->args[0];
+
+	if (idx >= HI3660_CLK_STUB_NUM) {
+		pr_err("%s: invalid index %u\n", __func__, idx);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return &hi3660_stub_clks[idx].hw;
+}
+
+static int hi3660_stub_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	unsigned int i;
+	int ret;
+
+	/* Use mailbox client without blocking */
+	stub_clk_chan.cl.dev = dev;
+	stub_clk_chan.cl.tx_done = NULL;
+	stub_clk_chan.cl.tx_block = false;
+	stub_clk_chan.cl.knows_txdone = false;
+
+	/* Allocate mailbox channel */
+	stub_clk_chan.mbox = mbox_request_channel(&stub_clk_chan.cl, 0);
+	if (IS_ERR(stub_clk_chan.mbox))
+		return PTR_ERR(stub_clk_chan.mbox);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	freq_reg = devm_ioremap(dev, res->start, resource_size(res));
+	if (!freq_reg)
+		return -ENOMEM;
+
+	freq_reg += HI3660_STUB_CLOCK_DATA;
+
+	for (i = 0; i < HI3660_CLK_STUB_NUM; i++) {
+		ret = devm_clk_hw_register(&pdev->dev, &hi3660_stub_clks[i].hw);
+		if (ret)
+			return ret;
+	}
+
+	return devm_of_clk_add_hw_provider(&pdev->dev, hi3660_stub_clk_hw_get,
+					   hi3660_stub_clks);
+}
+
+static const struct of_device_id hi3660_stub_clk_of_match[] = {
+	{ .compatible = "hisilicon,hi3660-stub-clk", },
+	{}
+};
+
+static struct platform_driver hi3660_stub_clk_driver = {
+	.probe	= hi3660_stub_clk_probe,
+	.driver = {
+		.name = "hi3660-stub-clk",
+		.of_match_table = hi3660_stub_clk_of_match,
+	},
+};
+
+static int __init hi3660_stub_clk_init(void)
+{
+	return platform_driver_register(&hi3660_stub_clk_driver);
+}
+subsys_initcall(hi3660_stub_clk_init);

include/dt-bindings/clock/hi3660-clock.h

@@ -208,4 +208,11 @@
 #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 */