[PATCH v3 10/13] clk: qcom: Add KPSS ACC/GCC driver

Stephen Boyd
2015-03-21T06:46:28Z

The ACC and GCC regions present in KPSSv1 contain registers to
control clocks and power to each Krait CPU and L2. For CPUfreq
purposes probe these devices and expose a mux clock that chooses
between PXO and PLL8.

Cc: <devicetree@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
.../devicetree/bindings/arm/msm/qcom,kpss-acc.txt | 7 ++
.../devicetree/bindings/arm/msm/qcom,kpss-gcc.txt | 28 +++++++
drivers/clk/qcom/Kconfig | 8 ++
drivers/clk/qcom/Makefile | 1 +
drivers/clk/qcom/kpss-xcc.c | 95 ++++++++++++++++++++++
5 files changed, 139 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/msm/qcom,kpss-gcc.txt
create mode 100644 drivers/clk/qcom/kpss-xcc.c

diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt b/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt
index 1333db9acfee..382a574a5c55 100644
--- a/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt
+++ b/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt
@@ -21,10 +21,17 @@ PROPERTIES
the register region. An optional second element specifies
the base address and size of the alias register region.

+- clock-output-names:
+ Usage: optional
+ Value type: <string>
+ Definition: Name of the output clock. Typically acpuX_aux where X is a
+ CPU number starting at 0.
+
Example:

clock-controller@2088000 {
compatible = "qcom,kpss-acc-v2";
reg = <0x02088000 0x1000>,
<0x02008000 0x1000>;
+ clock-output-names = "acpu0_aux";
};
diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,kpss-gcc.txt b/Documentation/devicetree/bindings/arm/msm/qcom,kpss-gcc.txt
new file mode 100644
index 000000000000..d1e12f16a28c
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/msm/qcom,kpss-gcc.txt
@@ -0,0 +1,28 @@
+Krait Processor Sub-system (KPSS) Global Clock Controller (GCC)
+
+PROPERTIES
+
+- compatible:
+ Usage: required
+ Value type: <string>
+ Definition: should be one of:
+ "qcom,kpss-gcc"
+
+- reg:
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: base address and size of the register region
+
+- clock-output-names:
+ Usage: required
+ Value type: <string>
+ Definition: Name of the output clock. Typically acpu_l2_aux indicating
+ an L2 cache auxiliary clock.
+
+Example:
+
+ l2cc: clock-controller@2011000 {
+ compatible = "qcom,kpss-gcc";
+ reg = <0x2011000 0x1000>;
+ clock-output-names = "acpu_l2_aux";
+ };
diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index 7b82b3c4e259..92eb883533d5 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -97,6 +97,14 @@ config QCOM_HFPLL
Say Y if you want to support CPU frequency scaling on devices
such as MSM8974, APQ8084, etc.

+config KPSS_XCC
+ tristate "KPSS Clock Controller"
+ depends on COMMON_CLK_QCOM
+ help
+ Support for the Krait ACC and GCC clock controllers. Say Y
+ if you want to support CPU frequency scaling on devices such
+ as MSM8960, APQ8064, etc.
+
config KRAIT_CLOCKS
bool
select KRAIT_L2_ACCESSORS
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index f8d7cfaee4a2..6327dd623773 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -22,4 +22,5 @@ obj-$(CONFIG_MSM_LCC_8960) += lcc-msm8960.o
obj-$(CONFIG_MSM_GCC_8974) += gcc-msm8974.o
obj-$(CONFIG_MSM_MMCC_8960) += mmcc-msm8960.o
obj-$(CONFIG_MSM_MMCC_8974) += mmcc-msm8974.o
+obj-$(CONFIG_KPSS_XCC) += kpss-xcc.o
obj-$(CONFIG_QCOM_HFPLL) += hfpll.o
diff --git a/drivers/clk/qcom/kpss-xcc.c b/drivers/clk/qcom/kpss-xcc.c
new file mode 100644
index 000000000000..abf6bfd053c1
--- /dev/null
+++ b/drivers/clk/qcom/kpss-xcc.c
@@ -0,0 +1,95 @@
+/* Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+
+static const char *aux_parents[] = {
+ "pll8_vote",
+ "pxo",
+};
+
+static unsigned int aux_parent_map[] = {
+ 3,
+ 0,
+};
+
+static const struct of_device_id kpss_xcc_match_table[] = {
+ { .compatible = "qcom,kpss-acc-v1", .data = (void *)1UL },
+ { .compatible = "qcom,kpss-gcc" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, kpss_xcc_match_table);
+
+static int kpss_xcc_driver_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *id;
+ struct clk *clk;
+ struct resource *res;
+ void __iomem *base;
+ const char *name;
+
+ id = of_match_device(kpss_xcc_match_table, &pdev->dev);
+ if (!id)
+ return -ENODEV;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ if (id->data) {
+ if (of_property_read_string_index(pdev->dev.of_node,
+ "clock-output-names", 0, &name))
+ return -ENODEV;
+ base += 0x14;
+ } else {
+ name = "acpu_l2_aux";
+ base += 0x28;
+ }
+
+ clk = clk_register_mux_table(&pdev->dev, name, aux_parents,
+ ARRAY_SIZE(aux_parents), 0, base, 0, 0x3,
+ 0, aux_parent_map, NULL);
+
+ platform_set_drvdata(pdev, clk);
+
+ return PTR_ERR_OR_ZERO(clk);
+}
+
+static int kpss_xcc_driver_remove(struct platform_device *pdev)
+{
+ clk_unregister_mux(platform_get_drvdata(pdev));
+ return 0;
+}
+
+static struct platform_driver kpss_xcc_driver = {
+ .probe = kpss_xcc_driver_probe,
+ .remove = kpss_xcc_driver_remove,
+ .driver = {
+ .name = "kpss-xcc",
+ .of_match_table = kpss_xcc_match_table,
+ },
+};
+module_platform_driver(kpss_xcc_driver);
+
+MODULE_DESCRIPTION("Krait Processor Sub System (KPSS) Clock Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:kpss-xcc");