Upstreaming MMP clock devicetree support

Daniel Drake dsd at laptop.org
Thu Jun 13 13:53:29 EDT 2013


Hi Mitch,

As mentioned, upstream now has APBC/APMU clock drivers, and I think there
are a couple of things in way that clock-dt.c interacts with the common
clock framework that upstream wouldn't approve of.

Here is my first attempt at a new approach, using the new upstream clock
drivers, and using the common clock framework in a way that is more
according to its design and use on other SoCs. Tested on XO-1.75 and XO-4.

If you have some time for some quick comments on my DT design before I
submit this, it would be much appreciated.


DT tweaks and kernel patch follow.

: +string  encode-string encode+  ;
: +int  encode-int encode+ ;
: +phandle  encode-phandle encode+ ;

\ APBC CLOCKS

dev /
new-device
   \ a.k.a. fast clock
   " vctcxo" device-name
   " fixed-clock" +compatible
   0 " #clock-cells" integer-property
   d# 26000000 " clock-frequency" integer-property
finish-device

new-device
   " clk32" device-name
   " fixed-clock" +compatible
   0 " #clock-cells" integer-property
   d# 3200 " clock-frequency" integer-property
finish-device

new-device
   " apb-clock" device-name
   
   h# d4015000 h# 1000 reg

   new-device
      " twsi-clocks" device-name
      " marvell,mmp-apb-clock" +compatible
      1 " #clock-cells" integer-property
      " /vctcxo" encode-phandle " clocks" property
      0 0 encode-bytes
      " TWSI1"     +string \ 0
      " TWSI2"     +string \ 1
      " TWSI3"     +string \ 2
      " TWSI4"     +string \ 3
      " TWSI5"     +string \ 4
      " TWSI6"     +string \ 5
      " clock-output-names" property

      0 0 encode-bytes
      h# 04 +int h# 08 +int h# 0c +int h# 10 +int h# 7c +int h# 80 +int
      " reg" property
   finish-device

   new-device
      " uart-clocks" device-name
      " marvell,mmp-apb-clock" +compatible
      1 " #clock-cells" integer-property
      " /vctcxo" encode-phandle " clocks" property

      0 0 encode-bytes
      " UART1"     +string \ 0
      " UART2"     +string \ 1
      " UART3"     +string \ 2
      " UART4"     +string \ 3
      " clock-output-names" property

      0 0 encode-bytes h# 2c +int h# 30 +int h# 34 +int h# 88 +int
      " reg" property
   finish-device

   new-device
      " ssp-clocks" device-name
      " marvell,mmp-apb-clock" +compatible
      1 " #clock-cells" integer-property
      " /vctcxo" encode-phandle " clocks" property

      0 0 encode-bytes
      " SSP0"      +string \ 0
      " SSP1"      +string \ 1
      " SSP2"      +string \ 2
      " SSP3"      +string \ 3
      " SSP4"      +string \ 4
      " SSP5"      +string \ 5
      " clock-output-names" property

      0 0 encode-bytes
      h# 4c +int h# 50 +int h# 54 +int h# 58 +int h# 5c +int h# 60 +int
      " reg" property
   finish-device

   new-device
      " misc-vctcxo-clocks" device-name
      " marvell,mmp-apb-clock" +compatible
      1 " #clock-cells" integer-property
      " /vctcxo" encode-phandle " clocks" property
      " GPIO" " clock-output-names" string-property
      38 " reg" integer-property
   finish-device

   new-device
      " thsens-clocks" device-name
      " marvell,mmp-apb-clock" +compatible
      1 " #clock-cells" integer-property
      " /vctcxo" encode-phandle " clocks" property

      0 0 encode-bytes
      " THSENS1"      +string \ 0
      " THSENS2"      +string \ 1
      " THSENS3"      +string \ 2
      " THSENS4"      +string \ 3
      " clock-output-names" property

      0 0 encode-bytes h# 90 +int h# 98 +int h# 9c +int h# a0 +int
      " reg" property
   finish-device


   new-device
      " rtc-clock" device-name
      " marvell,mmp-apb-clock" +compatible
      1 " #clock-cells" integer-property
      " /clk32" encode-phandle " clocks" property
      " RTC" " clock-output-names" string-property
      0 " reg" integer-property
   finish-device

finish-device
device-end

dev /i2c at d4011000 \ point to TWSI1
	" /apb-clock/twsi-clocks" encode-phandle d# 0 +int " clocks" property
device-end

dev /i2c at d4031000 \ point to TWSI2
	" /apb-clock/twsi-clocks" encode-phandle d# 1 +int " clocks" property
device-end

dev /i2c at d4033000 \ point to TWSI4
	" /apb-clock/twsi-clocks" encode-phandle d# 3 +int " clocks" property
device-end

dev /i2c at d4034000 \ point to TWSI6
	" /apb-clock/twsi-clocks" encode-phandle d# 5 +int " clocks" property
device-end

dev /uart at d4018000 \ point to UART3
	" /apb-clock/uart-clocks" encode-phandle d# 2 +int " clocks" property
device-end

dev /uart at d4017000 \ point to UART2
	" /apb-clock/uart-clocks" encode-phandle d# 1 +int " clocks" property
device-end

dev /uart at d4030000 \ point to UART1
	" /apb-clock/uart-clocks" encode-phandle d# 0 +int " clocks" property
device-end

dev /uart at d4016000 \ point to UART4
	" /apb-clock/uart-clocks" encode-phandle d# 3 +int " clocks" property
device-end

dev /gpio \ point to GPIO
	" /apb-clock/misc-vctcxo-clocks" encode-phandle d# 0 +int " clocks" property
device-end

dev /flash \ point to SSP1
	" /apb-clock/ssp-clocks" encode-phandle d# 1 +int " clocks" property
device-end

dev /ec-spi \ point to SSP3
	" /apb-clock/ssp-clocks" encode-phandle d# 3 +int " clocks" property
device-end

dev /wakeup-rtc \ point to RTC
	" /apb-clock/rtc-clock" encode-phandle d# 0 +int " clocks" property
device-end

[ifdef] mmp3
dev /thermal
      0 0 encode-bytes
	" /apb-clock/thsens-clocks" +phandle 0 +int
	" /apb-clock/thsens-clocks" +phandle 1 +int
	" /apb-clock/thsens-clocks" +phandle 2 +int
	" /apb-clock/thsens-clocks" +phandle 3 +int
	" clocks" property
device-end
[then]

\ APMU clocks
dev /
new-device
   " pll1" device-name
   " fixed-clock" +compatible
   0 " #clock-cells" integer-property
   d# 800000000 " clock-frequency" integer-property
finish-device

new-device
   " pll1_2" device-name
   " fixed-factor-clock" +compatible
   0 " #clock-cells" integer-property
   2 " clock-div" integer-property
   1 " clock-mult" integer-property
   " /pll1" encode-phandle " clocks" property
finish-device

new-device
   " pll1_4" device-name
   " fixed-factor-clock" +compatible
   0 " #clock-cells" integer-property
   4 " clock-div" integer-property
   1 " clock-mult" integer-property
   " /pll1" encode-phandle " clocks" property
finish-device

new-device
   " pll1_7" device-name
   " fixed-factor-clock" +compatible
   0 " #clock-cells" integer-property
   7 " clock-div" integer-property
   1 " clock-mult" integer-property
   " /pll1" encode-phandle " clocks" property
finish-device

new-device
   " usb_pll" device-name
   " fixed-clock" +compatible
   0 " #clock-cells" integer-property
   d# 480000000 " clock-frequency" integer-property
finish-device

new-device
   " apmu-clock" device-name
   h# d4282800 h# 1000 reg

   new-device
      " audio-clock" device-name
      " marvell,mmp-apmu-clock" +compatible
      0 " #clock-cells" integer-property
      " /pll1_2" encode-phandle " clocks" property
      h# 10c " reg" integer-property
      h# 13 " enable-mask" integer-property
   finish-device

   new-device
      " ccic-clock" device-name
      " marvell,mmp-apmu-clock" +compatible
      0 " #clock-cells" integer-property
      " /pll1_2" encode-phandle " clocks" property
      h# 50 " reg" integer-property
      h# 3f " enable-mask" integer-property
   finish-device

   new-device
      " wtm-clock" device-name
      " marvell,mmp-apmu-clock" +compatible
      0 " #clock-cells" integer-property
      " /pll1_4" encode-phandle " clocks" property
      h# 68 " reg" integer-property
      h# 1b " enable-mask" integer-property
   finish-device

   new-device
      " usb-clock" device-name
      " marvell,mmp-apmu-clock" +compatible
      0 " #clock-cells" integer-property
      " /usb_pll" encode-phandle " clocks" property
      h# 5c " reg" integer-property
      h# 09 " enable-mask" integer-property
   finish-device

   new-device
      " sdh1-clock" device-name
      " marvell,mmp-apmu-clock" +compatible
      0 " #clock-cells" integer-property
      " /pll1_4" encode-phandle " clocks" property
      h# 54 " reg" integer-property
      h# 41b " enable-mask" integer-property
   finish-device

   new-device
      " sdh2-clock" device-name
      " marvell,mmp-apmu-clock" +compatible
      0 " #clock-cells" integer-property
      " /pll1_4" encode-phandle " clocks" property
      h# 58 " reg" integer-property
      h# 1b " enable-mask" integer-property
   finish-device

[ifdef] mmp3
   new-device
      " sdh5-clock" device-name
      " marvell,mmp-apmu-clock" +compatible
      0 " #clock-cells" integer-property
      " /pll1_4" encode-phandle " clocks" property
      h# 15c " reg" integer-property
      h# 1b " enable-mask" integer-property
   finish-device
[then]

   \ FIXME should be mmp2-only? does appear in XO4 DT
   new-device
      " mspro-clock" device-name
      " marvell,mmp-apmu-clock" +compatible
      0 " #clock-cells" integer-property
      " /pll1_4" encode-phandle " clocks" property
      h# d8 " reg" integer-property
      h# 3f " enable-mask" integer-property
   finish-device

   new-device
      " lcd-clock" device-name
      " marvell,mmp-apmu-clock" +compatible
      0 " #clock-cells" integer-property
      " /pll1_7" encode-phandle " clocks" property
      h# 4c " reg" integer-property
      h# 71b " enable-mask" integer-property
   finish-device

   new-device
      " vmeta-clock" device-name
      " marvell,mmp-apmu-clock" +compatible
      0 " #clock-cells" integer-property
      " /pll1_2" encode-phandle " clocks" property
      h# a4 " reg" integer-property
      h# 1b " enable-mask" integer-property
   finish-device

   new-device
      " gc-clock" device-name
      " marvell,mmp-apmu-clock" +compatible
      0 " #clock-cells" integer-property
      " /pll1_4" encode-phandle " clocks" property
      h# cc " reg" integer-property
      h# 0f " enable-mask" integer-property
   finish-device

finish-device
device-end

dev /audio
	" /apmu-clock/audio-clock" encode-phandle " clocks" property
device-end

dev /sspa
	" /apmu-clock/audio-clock" encode-phandle " clocks" property
device-end

dev /camera
	" /apmu-clock/ccic-clock" encode-phandle " clocks" property
device-end

dev /ap-sp
	" /apmu-clock/wtm-clock" encode-phandle " clocks" property
device-end

dev /usb
	" /apmu-clock/usb-clock" encode-phandle " clocks" property
device-end

dev /sd/sdhci at d4280000
	" /apmu-clock/sdh1-clock" encode-phandle " clocks" property
device-end

dev /sd/sdhci at d4281000
	\ FIXME clock should be mmp2-only? does appear in XO4 DT
	" /apmu-clock/mspro-clock" encode-phandle " clocks" property
device-end

dev /sd/sdhci at d4280800
	" /apmu-clock/sdh2-clock" encode-phandle " clocks" property
device-end

[ifdef] mmp3
dev /sd/sdhci at d4217000
	" /apmu-clock/sdh5-clock" encode-phandle " clocks" property
device-end
[then]

dev /display
   " /apmu-clock/lcd-clock" encode-phandle " clocks" property
device-end

dev /vmeta
   " /apmu-clock/vmeta-clock" encode-phandle " clocks" property
device-end

[ifdef] mmp3
dev /gpu
   " /apmu-clock/gc-clock" encode-phandle " clocks" property
device-end
[then]




[PATCH] clk: mmp: add support for DT-defined clocks

Add support to the existing mmp clock drivers for clocks to be defined
in the device tree. This will be used on OLPC MMP2/MMP3-based laptops.

If clock info cannot be found in the device tree, we fall back to the
static clock initialization already present.

Signed-off-by: Daniel Drake <dsd at laptop.org>
---
 .../devicetree/bindings/clock/mmp-apbc.txt         | 30 ++++++++++
 .../devicetree/bindings/clock/mmp-apmu.txt         | 30 ++++++++++
 drivers/clk/mmp/clk-apbc.c                         | 66 +++++++++++++++++++++-
 drivers/clk/mmp/clk-apmu.c                         | 37 +++++++++++-
 drivers/clk/mmp/clk-mmp2.c                         | 19 ++++++-
 5 files changed, 179 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/mmp-apbc.txt
 create mode 100644 Documentation/devicetree/bindings/clock/mmp-apmu.txt

diff --git a/Documentation/devicetree/bindings/clock/mmp-apbc.txt b/Documentation/devicetree/bindings/clock/mmp-apbc.txt
new file mode 100644
index 0000000..88e1253
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/mmp-apbc.txt
@@ -0,0 +1,30 @@
+* Clock bindings for Marvell MMP Advanced Peripheral Bus clock
+
+Parent apb-clock node
+=====================
+Required properties:
+- reg: Address and length of the APB clock unit registers
+
+
+Child peripheral clock nodes
+============================
+Required properties:
+- compatible : shall be "marvell,mmp-apb-clock"
+- #clock-cells : from common clock binding; shall be set to 1
+- clocks : parent clock, from common clock binding
+- clock-output-names : Array of clock names, from common clock binding
+- reg : Array of control register offsets into APB clock unit register space
+
+
+Example:
+apbc: apb-clock {
+	reg = <0xd4015000 0x1000>;
+
+	twsi-clocks {
+		compatible = "marvell,mmp-apb-clock";
+		#clock-cells = <1>;
+		clocks = <&vctvxo-clock>;
+		clock-output-names = "TWSI0", "TWSI1";
+		reg = <0x04 0x08>;
+	};
+};
diff --git a/Documentation/devicetree/bindings/clock/mmp-apmu.txt b/Documentation/devicetree/bindings/clock/mmp-apmu.txt
new file mode 100644
index 0000000..18bb0f9
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/mmp-apmu.txt
@@ -0,0 +1,30 @@
+* Clock bindings for Marvell MMP Application Subsystem Power Management Unit
+
+Parent apmu-clock node
+=====================
+Required properties:
+- reg: Address and length of the CPU Subsystem PMU registers
+
+
+Child peripheral clock nodes
+============================
+Required properties:
+- compatible : shall be "marvell,mmp-apmu-clock"
+- #clock-cells : from common clock binding; shall be set to 0
+- clocks : parent clock, from common clock binding
+- reg : Control register offsets into parent register space
+- enable-mask : The bits to be set in the register to enable the clock, or
+                cleared to disable.
+
+Example:
+apmu-clock {
+	reg = <0xd4282800 0x1000>;
+
+	usb-clock {
+		compatible = "marvell,mmp-apmu-clock";
+		#clock-cells = <0>;
+		clocks = <&usb_pll>;
+		reg = <0x5c>;
+		enable-mask = <0x09>;
+	};
+};
diff --git a/drivers/clk/mmp/clk-apbc.c b/drivers/clk/mmp/clk-apbc.c
index 89a146a..d53bc79 100644
--- a/drivers/clk/mmp/clk-apbc.c
+++ b/drivers/clk/mmp/clk-apbc.c
@@ -15,6 +15,8 @@
 #include <linux/err.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 
 #include "clk.h"
 
@@ -129,8 +131,70 @@ struct clk *mmp_clk_register_apbc(const char *name, const char *parent_name,
 	apbc->hw.init = &init;
 
 	clk = clk_register(NULL, &apbc->hw);
-	if (IS_ERR(clk))
+	if (WARN_ON(IS_ERR(clk)))
 		kfree(apbc);
 
 	return clk;
 }
+
+static void __init mmp_apbc_dt_init(struct device_node *node)
+{
+	struct device_node *parent = of_get_parent(node);
+	const __be32 *regs;
+	struct clk *clk;
+	int rc;
+	int len;
+	int num_clocks;
+	int clock_num;
+	void __iomem *baseaddr;
+	const char *clock_name;
+	const char *parent_name;
+	struct clk **clks;
+	struct clk_onecell_data *clk_data;
+
+	regs = of_get_property(node, "reg", &len);
+	if (WARN_ON(!regs || (len % sizeof(__be32) != 0)))
+		return;
+	num_clocks = len / sizeof(__be32);
+
+	baseaddr = of_iomap(parent, 0);
+	of_node_put(parent);
+	if (WARN_ON(!baseaddr))
+		return;
+
+	clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
+	if (WARN_ON(!clk_data))
+		goto err_clk_data;
+
+	clks = kzalloc(num_clocks * sizeof(*clks), GFP_KERNEL);
+	if (WARN_ON(!clks))
+		goto err_clks;
+
+	clock_name = of_get_property(node, "clock-output-names", NULL);
+	parent_name = of_clk_get_parent_name(node, 0);
+
+	for (clock_num = 0; clock_num < num_clocks; clock_num++) {
+		void __iomem *clock_addr;
+		clock_addr = baseaddr + be32_to_cpup(regs + clock_num);
+
+		clk = mmp_clk_register_apbc(clock_name, parent_name,
+					    clock_addr, 10, 0);
+		if (IS_ERR(clk))
+			return;
+		clock_name += strlen(clock_name) + 1;
+		clks[clock_num] = clk;
+	}
+
+	clk_data->clk_num = num_clocks;
+	clk_data->clks = clks;
+	rc = of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
+	WARN_ON(rc);
+	return;
+
+err_clks:
+	kfree(clk_data);
+err_clk_data:
+	iounmap(baseaddr);
+
+}
+CLK_OF_DECLARE(mmp2_apbc, "marvell,mmp-apb-clock", mmp_apbc_dt_init);
diff --git a/drivers/clk/mmp/clk-apmu.c b/drivers/clk/mmp/clk-apmu.c
index 4f4d8c5..dfcecc9 100644
--- a/drivers/clk/mmp/clk-apmu.c
+++ b/drivers/clk/mmp/clk-apmu.c
@@ -15,6 +15,8 @@
 #include <linux/err.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 
 #include "clk.h"
 
@@ -22,7 +24,6 @@
 struct clk_apmu {
 	struct clk_hw   hw;
 	void __iomem    *base;
-	u32		rst_mask;
 	u32		enable_mask;
 };
 
@@ -85,3 +86,37 @@ struct clk *mmp_clk_register_apmu(const char *name, const char *parent_name,
 
 	return clk;
 }
+
+static void __init mmp_apmu_dt_init(struct device_node *node)
+{
+	struct device_node *parent = of_get_parent(node);
+	const char *clk_name = node->name;
+	void __iomem *baseaddr;
+	struct clk *clk;
+	u32 reg;
+	u32 enable_mask;
+	int rc;
+
+	rc = of_property_read_u32(node, "reg", &reg);
+	if (WARN_ON(rc))
+		return;
+
+	rc = of_property_read_u32(node, "enable-mask", &enable_mask);
+	if (WARN_ON(rc))
+		return;
+
+	baseaddr = of_iomap(parent, 0);
+	of_node_put(parent);
+	if (WARN_ON(!baseaddr))
+		return;
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+	clk = mmp_clk_register_apmu(clk_name, of_clk_get_parent_name(node, 0),
+				    baseaddr + reg, enable_mask);
+	if (WARN_ON(IS_ERR(clk)))
+		return;
+
+	rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
+	WARN_ON(rc);
+}
+CLK_OF_DECLARE(mmp2_apmu, "marvell,mmp-apmu-clock", mmp_apmu_dt_init);
diff --git a/drivers/clk/mmp/clk-mmp2.c b/drivers/clk/mmp/clk-mmp2.c
index 6f654c3..6abb083 100644
--- a/drivers/clk/mmp/clk-mmp2.c
+++ b/drivers/clk/mmp/clk-mmp2.c
@@ -15,6 +15,7 @@
 #include <linux/io.h>
 #include <linux/delay.h>
 #include <linux/err.h>
+#include <linux/of.h>
 
 #include <mach/addr-map.h>
 
@@ -73,7 +74,7 @@ static const char *sdh_parent[] = {"pll1_4", "pll2", "usb_pll", "pll1"};
 static const char *disp_parent[] = {"pll1", "pll1_16", "pll2", "vctcxo"};
 static const char *ccic_parent[] = {"pll1_2", "pll1_16", "vctcxo"};
 
-void __init mmp2_clk_init(void)
+static void __init mmp2_clk_init_static(void)
 {
 	struct clk *clk;
 	struct clk *vctcxo;
@@ -445,3 +446,19 @@ void __init mmp2_clk_init(void)
 				apmu_base + APMU_CCIC1, 0x300);
 	clk_register_clkdev(clk, "sphyclk", "mmp-ccic.1");
 }
+
+void __init mmp2_clk_init(void)
+{
+	struct device_node *node;
+
+	/* The presence of the ABP clock node in the device tree indicates
+	 * that we should use the DT for clock setup. */
+	node = of_find_compatible_node(NULL, NULL, "marvell,mmp-apb-clock");
+	if (node) {
+		of_node_put(node);
+		of_clk_init(NULL);
+	} else {
+		/* Fallback to static setup */
+		mmp2_clk_init_static();
+	}
+}
-- 
1.8.1.4




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