[v4,3/3] clk: qcom: Add A53 clock driver

diff --git a/Documentation/devicetree/bindings/clock/qcom,a53cc.txt b/Documentation/devicetree/bindings/clock/qcom,a53cc.txt
new file mode 100644
index 000000000000..3a1e8e6675ab
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/qcom,a53cc.txt
@@ -0,0 +1,23 @@ 
+Qualcomm A53 CPU Clock Controller Binding
+------------------------------------------------
+The A53 CPU Clock Controller is hardware, which provides a combined
+mux and divider functionality for the CPU clocks. It can choose between
+a fixed rate clock and the dedicated A53 PLL.
+
+Required properties :
+- compatible : shall contain:
+
+			"qcom,a53cc"
+
+- reg : shall contain base register location and length
+	of the APCS region
+- #clock-cells : shall contain 1
+
+Example:
+
+	apcs: syscon@b011000 {
+		compatible = "qcom,a53cc", "syscon";
+		reg = <0x0b011000 0x1000>;
+		#clock-cells = <1>;
+	};
+
diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index d06cf687be4f..27a1622ca891 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -132,3 +132,11 @@  config QCOM_A53PLL
 	  support for CPU frequencies above 1GHz.
 	  Say Y if you want to support CPU frequency scaling on devices
 	  such as MSM8916.
+
+config QCOM_A53CC
+	bool "A53 Clock Controller"
+	depends on COMMON_CLK_QCOM && QCOM_A53PLL
+	help
+	  Support for the A53 clock controller on some Qualcomm devices.
+	  Say Y if you want to support CPU frequency scaling on devices
+	  such as MSM8916.
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index bc7637516a6e..9a67697b9540 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -26,4 +26,5 @@  obj-$(CONFIG_MSM_GCC_8996) += gcc-msm8996.o
 obj-$(CONFIG_MSM_MMCC_8960) += mmcc-msm8960.o
 obj-$(CONFIG_MSM_MMCC_8974) += mmcc-msm8974.o
 obj-$(CONFIG_MSM_MMCC_8996) += mmcc-msm8996.o
+obj-$(CONFIG_QCOM_A53CC) += a53cc.o
 obj-$(CONFIG_QCOM_A53PLL) += a53-pll.o
diff --git a/drivers/clk/qcom/a53cc.c b/drivers/clk/qcom/a53cc.c
new file mode 100644
index 000000000000..8958464ee7fb
--- /dev/null
+++ b/drivers/clk/qcom/a53cc.c
@@ -0,0 +1,166 @@ 
+/*
+ * Copyright (c) 2015, Linaro Limited
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.h>
+#include <linux/clk-provider.h>
+#include <linux/cpu.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "clk-regmap.h"
+#include "clk-regmap-mux-div.h"
+
+enum {
+	P_GPLL0,
+	P_A53PLL,
+};
+
+static const struct parent_map gpll0_a53cc_map[] = {
+	{ P_GPLL0, 4 },
+	{ P_A53PLL, 5 },
+};
+
+static const char * const gpll0_a53cc[] = {
+	"gpll0_vote",
+	"a53pll",
+};
+
+static const struct regmap_config a53cc_regmap_config = {
+	.reg_bits		= 32,
+	.reg_stride		= 4,
+	.val_bits		= 32,
+	.max_register		= 0x1000,
+	.fast_io		= true,
+	.val_format_endian	= REGMAP_ENDIAN_LITTLE,
+};
+
+static const struct of_device_id qcom_a53cc_match_table[] = {
+	{ .compatible = "qcom,a53cc" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, qcom_a53cc_match_table);
+
+/*
+ * We use the notifier function for switching to a temporary safe configuration
+ * (mux and divider), while the a53 pll is reconfigured.
+ */
+static int a53cc_notifier_cb(struct notifier_block *nb, unsigned long event,
+			     void *data)
+{
+	int ret = 0;
+	struct clk_regmap_mux_div *md = container_of(nb,
+						     struct clk_regmap_mux_div,
+						     clk_nb);
+
+	if (event == PRE_RATE_CHANGE)
+		ret = __mux_div_set_src_div(md, md->safe_src, md->safe_div);
+
+	return notifier_from_errno(ret);
+}
+
+static int qcom_a53cc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct clk_regmap_mux_div *a53cc;
+	struct resource *res;
+	void __iomem *base;
+	struct clk *clk, *pclk;
+	struct regmap *regmap;
+	struct clk_init_data init;
+	int ret;
+
+	a53cc = devm_kzalloc(dev, sizeof(*a53cc), GFP_KERNEL);
+	if (!a53cc)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	a53cc->reg_offset = 0x50,
+	a53cc->hid_width = 5,
+	a53cc->hid_shift = 0,
+	a53cc->src_width = 3,
+	a53cc->src_shift = 8,
+	a53cc->safe_src = 4,
+	a53cc->safe_div = 3,
+	a53cc->parent_map = gpll0_a53cc_map,
+
+	init.name = "a53mux",
+	init.parent_names = gpll0_a53cc,
+	init.num_parents = 2,
+	init.ops = &clk_regmap_mux_div_ops,
+	init.flags = CLK_SET_RATE_PARENT;
+	a53cc->clkr.hw.init = &init;
+
+	pclk = __clk_lookup(gpll0_a53cc[1]);
+	if (!pclk)
+		return -EPROBE_DEFER;
+
+	ret = clk_prepare_enable(pclk);
+	if (ret) {
+		dev_err(dev, "failed to enable %s: %d\n", gpll0_a53cc[1], ret);
+		return ret;
+	}
+
+	a53cc->clk_nb.notifier_call = a53cc_notifier_cb;
+	ret = clk_notifier_register(pclk, &a53cc->clk_nb);
+	if (ret) {
+		dev_err(dev, "failed to register clock notifier: %d\n", ret);
+		return ret;
+	}
+
+	regmap = devm_regmap_init_mmio(dev, base, &a53cc_regmap_config);
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
+		dev_err(dev, "failed to init regmap mmio: %d\n", ret);
+		goto err;
+	}
+
+	a53cc->clkr.regmap = regmap;
+
+	clk = devm_clk_register_regmap(dev, &a53cc->clkr);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		dev_err(dev, "failed to register regmap clock: %d\n", ret);
+		goto err;
+	}
+
+	ret = of_clk_add_provider(dev->of_node, of_clk_src_simple_get, clk);
+	if (ret) {
+		dev_err(dev, "failed to add clock provider: %d\n", ret);
+		goto err;
+	}
+
+	return 0;
+err:
+	clk_notifier_unregister(pclk, &a53cc->clk_nb);
+	return ret;
+}
+
+static struct platform_driver qcom_a53cc_driver = {
+	.probe = qcom_a53cc_probe,
+	.driver = {
+		.name = "qcom-a53cc",
+		.of_match_table = qcom_a53cc_match_table,
+	},
+};
+
+module_platform_driver(qcom_a53cc_driver);
+MODULE_DESCRIPTION("Qualcomm A53 Clock Controller Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:qcom-a53cc");