3 files changed, 150 insertions, 0 deletions

diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index 49db9fda6548..769e27353e1b 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -22,6 +22,17 @@ config QCOM_A53PLL
 	  Say Y if you want to support higher CPU frequencies on MSM8916
 	  devices.
 
+config QCOM_CLK_APCS_MSM8916
+	tristate "MSM8916 APCS Clock Controller"
+	depends on COMMON_CLK_QCOM
+	depends on QCOM_APCS_IPC || COMPILE_TEST
+	default ARCH_QCOM
+	help
+	  Support for the APCS Clock Controller on msm8916 devices. The
+	  APCS is managing the mux and divider which feeds the CPUs.
+	  Say Y if you want to support CPU frequency scaling on devices
+	  such as msm8916.
+
 config QCOM_CLK_RPM
 	tristate "RPM based Clock Controller"
 	depends on COMMON_CLK_QCOM && MFD_QCOM_RPM
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 7c51d877f967..0408cebf38d4 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -34,5 +34,6 @@ 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_A53PLL) += a53-pll.o
+obj-$(CONFIG_QCOM_CLK_APCS_MSM8916) += apcs-msm8916.o
 obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
 obj-$(CONFIG_QCOM_CLK_SMD_RPM) += clk-smd-rpm.o
diff --git a/drivers/clk/qcom/apcs-msm8916.c b/drivers/clk/qcom/apcs-msm8916.c
new file mode 100644
index 000000000000..246957f1a413
--- /dev/null
+++ b/drivers/clk/qcom/apcs-msm8916.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Qualcomm APCS clock controller driver
+ *
+ * Copyright (c) 2017, Linaro Limited
+ * Author: Georgi Djakov <georgi.djakov@linaro.org>
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "clk-regmap.h"
+#include "clk-regmap-mux-div.h"
+
+static const u32 gpll0_a53cc_map[] = { 4, 5 };
+
+static const char * const gpll0_a53cc[] = {
+	"gpll0_vote",
+	"a53pll",
+};
+
+/*
+ * 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)
+		/* set the mux and divider to safe frequency (400mhz) */
+		ret = mux_div_set_src_div(md, 4, 3);
+
+	return notifier_from_errno(ret);
+}
+
+static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device *parent = dev->parent;
+	struct clk_regmap_mux_div *a53cc;
+	struct regmap *regmap;
+	struct clk_init_data init = { };
+	int ret;
+
+	regmap = dev_get_regmap(parent, NULL);
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
+		dev_err(dev, "failed to get regmap: %d\n", ret);
+		return ret;
+	}
+
+	a53cc = devm_kzalloc(dev, sizeof(*a53cc), GFP_KERNEL);
+	if (!a53cc)
+		return -ENOMEM;
+
+	init.name = "a53mux";
+	init.parent_names = gpll0_a53cc;
+	init.num_parents = ARRAY_SIZE(gpll0_a53cc);
+	init.ops = &clk_regmap_mux_div_ops;
+	init.flags = CLK_SET_RATE_PARENT;
+
+	a53cc->clkr.hw.init = &init;
+	a53cc->clkr.regmap = regmap;
+	a53cc->reg_offset = 0x50;
+	a53cc->hid_width = 5;
+	a53cc->hid_shift = 0;
+	a53cc->src_width = 3;
+	a53cc->src_shift = 8;
+	a53cc->parent_map = gpll0_a53cc_map;
+
+	a53cc->pclk = devm_clk_get(parent, NULL);
+	if (IS_ERR(a53cc->pclk)) {
+		ret = PTR_ERR(a53cc->pclk);
+		dev_err(dev, "failed to get clk: %d\n", ret);
+		return ret;
+	}
+
+	a53cc->clk_nb.notifier_call = a53cc_notifier_cb;
+	ret = clk_notifier_register(a53cc->pclk, &a53cc->clk_nb);
+	if (ret) {
+		dev_err(dev, "failed to register clock notifier: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_clk_register_regmap(dev, &a53cc->clkr);
+	if (ret) {
+		dev_err(dev, "failed to register regmap clock: %d\n", ret);
+		goto err;
+	}
+
+	ret = of_clk_add_hw_provider(parent->of_node, of_clk_hw_simple_get,
+				     &a53cc->clkr.hw);
+	if (ret) {
+		dev_err(dev, "failed to add clock provider: %d\n", ret);
+		goto err;
+	}
+
+	platform_set_drvdata(pdev, a53cc);
+
+	return 0;
+
+err:
+	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
+	return ret;
+}
+
+static int qcom_apcs_msm8916_clk_remove(struct platform_device *pdev)
+{
+	struct clk_regmap_mux_div *a53cc = platform_get_drvdata(pdev);
+	struct device *parent = pdev->dev.parent;
+
+	clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
+	of_clk_del_provider(parent->of_node);
+
+	return 0;
+}
+
+static struct platform_driver qcom_apcs_msm8916_clk_driver = {
+	.probe = qcom_apcs_msm8916_clk_probe,
+	.remove = qcom_apcs_msm8916_clk_remove,
+	.driver = {
+		.name = "qcom-apcs-msm8916-clk",
+	},
+};
+module_platform_driver(qcom_apcs_msm8916_clk_driver);
+
+MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Qualcomm MSM8916 APCS clock driver");