Re: [PATCH] clk: x86: Add ST oscout platform clock

From: Agrawal, Akshu
Date: Thu May 03 2018 - 04:15:42 EST




On 5/2/2018 3:28 AM, Stephen Boyd wrote:
Quoting Akshu Agrawal (2018-04-30 00:06:53)
diff --git a/drivers/clk/x86/Makefile b/drivers/clk/x86/Makefile
index 1367afb..f7ebae1 100644
--- a/drivers/clk/x86/Makefile
+++ b/drivers/clk/x86/Makefile
@@ -1,3 +1,4 @@
clk-x86-lpss-objs := clk-lpt.o
obj-$(CONFIG_X86_INTEL_LPSS) += clk-x86-lpss.o
obj-$(CONFIG_PMC_ATOM) += clk-pmc-atom.o
+obj-$(CONFIG_X86) += clk-st.o

No desire to make a Kconfig for this driver so it isn't included all the
time on x86 devices that don't have this hardware?


Accepted, will use AMD specific config.

diff --git a/drivers/clk/x86/clk-st.c b/drivers/clk/x86/clk-st.c
new file mode 100644
index 0000000..6ac0dc5
--- /dev/null
+++ b/drivers/clk/x86/clk-st.c
@@ -0,0 +1,80 @@
+/*
+ * clock framework for AMD Stoney based clocks
+ *
+ * Copyright 2018 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.

Can you use the SPDX tags here?


Accepted. Will add in v2.

+ */
+
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/platform_data/clk-st.h>
+#include <linux/platform_device.h>
+
+/* Clock Driving Strength 2 register */
+#define CLKDRVSTR2 0x28
+/* Clock Control 1 register */
+#define MISCCLKCNTL1 0x40
+/* Auxiliary clock1 enable bit */
+#define OSCCLKENB 2
+/* 25Mhz auxiliary output clock freq bit */
+#define OSCOUT1CLK25MHZ 16
+
+static const char * const clk_oscout1_parents[] = { "clk48MHz", "clk25MHz" };
+
+static int st_clk_probe(struct platform_device *pdev)
+{
+ struct st_clk_data *st_data;
+ struct clk *clk_48m;
+ struct clk *clk_25m;
+ struct clk *clk_oscout1_mux;
+ struct clk *clk_oscout1;
+
+ st_data = dev_get_platdata(&pdev->dev);
+ if (!st_data || !st_data->base)
+ return -EINVAL;
+
+ clk_48m = clk_register_fixed_rate(NULL, "clk48MHz", NULL, 0,
+ 48000000);
+ clk_25m = clk_register_fixed_rate(NULL, "clk25MHz", NULL, 0,
+ 25000000);
+
+ clk_oscout1_mux = clk_register_mux(NULL, "oscout1_mux",
+ clk_oscout1_parents, ARRAY_SIZE(clk_oscout1_parents),
+ 0, st_data->base + CLKDRVSTR2, OSCOUT1CLK25MHZ, 3, 0, NULL);
+
+ clk_set_parent(clk_oscout1_mux, clk_25m);
+
+ clk_oscout1 = clk_register_gate(NULL, "oscout1", "oscout1_mux",
+ 0, st_data->base + MISCCLKCNTL1, OSCCLKENB,
+ CLK_GATE_SET_TO_DISABLE, NULL);
+
+ clk_register_clkdev(clk_oscout1, "oscout1", NULL);

Can you use the clk_hw registration and clkdev APIs? It would mean that
clk_set_parent() call up above would still be needed but I guess that's
OK. We don't currently have a way for non-DT based drivers to configure
the parents of a clk when it's registered.


Accepted, Changing in v2 to use clk_hw_register_.

+
+ return 0;
+}
+
diff --git a/include/linux/platform_data/clk-st.h b/include/linux/platform_data/clk-st.h
new file mode 100644
index 0000000..5ede980
--- /dev/null
+++ b/include/linux/platform_data/clk-st.h
@@ -0,0 +1,32 @@
+/*
+ * clock framework for AMD Stoney based clock
+ *
+ * Copyright 2018 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef __CLK_ST_H
+#define __CLK_ST_H
+
+struct st_clk_data {
+ void __iomem *base;

Can you include compiler.h in this file for the __iomem usage?


Accepted. Will add in v2.

Thanks,
Akshu