[PATCH v7 1/3] PM: wakeup: Add routine to help fetch wakeup source object.

[PATCH v7 1/3] PM: wakeup: Add routine to help fetch wakeup source object.

[Ran Wang]

Some user might want to go through all registered wakeup sources
and doing things accordingly. For example, SoC PM driver might need to
do HW programming to prevent powering down specific IP which wakeup
source depending on. So add this API to help walk through all registered
wakeup source objects on that list and return them one by one.

Signed-off-by: Ran Wang <ran.wang_1@nxp.com>
Tested-by: Leonard Crestez <leonard.crestez@nxp.com>
---
Change in v7:
	- Remove define of member *dev in wake_irq to fix conflict with commit 
	c8377adfa781 ("PM / wakeup: Show wakeup sources stats in sysfs"), user 
	will use ws->dev->parent instead.
	- Remove '#include <linux/of_device.h>' because it is not used.

Change in v6:
	- Add wakeup_source_get_star() and wakeup_source_get_stop() to aligned 
	with wakeup_sources_stats_seq_start/nex/stop.

Change in v5:
	- Update commit message, add decription of walk through all wakeup
	source objects.
	- Add SCU protection in function wakeup_source_get_next().
	- Rename wakeup_source member 'attached_dev' to 'dev' and move it up
	(before wakeirq).

Change in v4:
	- None.

Change in v3:
	- Adjust indentation of *attached_dev;.

Change in v2:
	- None.

 drivers/base/power/wakeup.c | 37 +++++++++++++++++++++++++++++++++++++
 include/linux/pm_wakeup.h   |  3 +++
 2 files changed, 40 insertions(+)

diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index 5817b51..dee1b09 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -248,6 +248,43 @@ void wakeup_source_unregister(struct wakeup_source *ws)
 EXPORT_SYMBOL_GPL(wakeup_source_unregister);
 
 /**
+ * wakeup_source_get_star - Begin a walk on wakeup source list
+ * @srcuidx: Lock index allocated for this caller.
+ */
+struct wakeup_source *wakeup_source_get_start(int *srcuidx)
+{
+	struct list_head *ws_head = &wakeup_sources;
+
+	*srcuidx = srcu_read_lock(&wakeup_srcu);
+
+	return list_entry_rcu(ws_head->next, struct wakeup_source, entry);
+}
+EXPORT_SYMBOL_GPL(wakeup_source_get_start);
+
+/**
+ * wakeup_source_get_next - Get next wakeup source from the list
+ * @ws: Previous wakeup source object
+ */
+struct wakeup_source *wakeup_source_get_next(struct wakeup_source *ws)
+{
+	struct list_head *ws_head = &wakeup_sources;
+
+	return list_next_or_null_rcu(ws_head, &ws->entry,
+				struct wakeup_source, entry);
+}
+EXPORT_SYMBOL_GPL(wakeup_source_get_next);
+
+/**
+ * wakeup_source_get_stop - Stop a walk on wakeup source list
+ * @idx: Dedicated lock index of this caller.
+ */
+void wakeup_source_get_stop(int idx)
+{
+	srcu_read_unlock(&wakeup_srcu, idx);
+}
+EXPORT_SYMBOL_GPL(wakeup_source_get_stop);
+
+/**
  * device_wakeup_attach - Attach a wakeup source object to a device object.
  * @dev: Device to handle.
  * @ws: Wakeup source object to attach to @dev.
diff --git a/include/linux/pm_wakeup.h b/include/linux/pm_wakeup.h
index 661efa0..172e76c 100644
--- a/include/linux/pm_wakeup.h
+++ b/include/linux/pm_wakeup.h
@@ -92,6 +92,9 @@ extern void wakeup_source_remove(struct wakeup_source *ws);
 extern struct wakeup_source *wakeup_source_register(struct device *dev,
 						    const char *name);
 extern void wakeup_source_unregister(struct wakeup_source *ws);
+extern struct wakeup_source *wakeup_source_get_start(int *srcuidx);
+extern struct wakeup_source *wakeup_source_get_next(struct wakeup_source *ws);
+extern void wakeup_source_get_stop(int idx);
 extern int device_wakeup_enable(struct device *dev);
 extern int device_wakeup_disable(struct device *dev);
 extern void device_set_wakeup_capable(struct device *dev, bool capable);
-- 
2.7.4

[PATCH v7 2/3] Documentation: dt: binding: fsl: Add 'little-endian' and update Chassis define

[Ran Wang]

By default, QorIQ SoC's RCPM register block is Big Endian. But
there are some exceptions, such as LS1088A and LS2088A, are
Little Endian. So add this optional property to help identify
them.

Actually LS2021A and other Layerscapes won't totally follow Chassis
2.1, so separate them from powerpc SoC.

Signed-off-by: Ran Wang <ran.wang_1@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
Change in v7:
	- None.

Change in v6:
	- None.

Change in v5:
	- Add 'Reviewed-by: Rob Herring <robh@kernel.org>' to commit message.
	- Rename property 'fsl,#rcpm-wakeup-cells' to '#fsl,rcpm-wakeup-cells'.
	please see https://lore.kernel.org/patchwork/patch/1101022/

Change in v4:
	- Adjust indectation of 'ls1021a, ls1012a, ls1043a, ls1046a'.

Change in v3:
	- None.

Change in v2:
	- None.

 Documentation/devicetree/bindings/soc/fsl/rcpm.txt | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/soc/fsl/rcpm.txt b/Documentation/devicetree/bindings/soc/fsl/rcpm.txt
index e284e4e..5a33619 100644
--- a/Documentation/devicetree/bindings/soc/fsl/rcpm.txt
+++ b/Documentation/devicetree/bindings/soc/fsl/rcpm.txt
@@ -5,7 +5,7 @@ and power management.
 
 Required properites:
   - reg : Offset and length of the register set of the RCPM block.
-  - fsl,#rcpm-wakeup-cells : The number of IPPDEXPCR register cells in the
+  - #fsl,rcpm-wakeup-cells : The number of IPPDEXPCR register cells in the
 	fsl,rcpm-wakeup property.
   - compatible : Must contain a chip-specific RCPM block compatible string
 	and (if applicable) may contain a chassis-version RCPM compatible
@@ -20,6 +20,7 @@ Required properites:
 	* "fsl,qoriq-rcpm-1.0": for chassis 1.0 rcpm
 	* "fsl,qoriq-rcpm-2.0": for chassis 2.0 rcpm
 	* "fsl,qoriq-rcpm-2.1": for chassis 2.1 rcpm
+	* "fsl,qoriq-rcpm-2.1+": for chassis 2.1+ rcpm
 
 All references to "1.0" and "2.0" refer to the QorIQ chassis version to
 which the chip complies.
@@ -27,14 +28,19 @@ Chassis Version		Example Chips
 ---------------		-------------------------------
 1.0				p4080, p5020, p5040, p2041, p3041
 2.0				t4240, b4860, b4420
-2.1				t1040, ls1021
+2.1				t1040,
+2.1+				ls1021a, ls1012a, ls1043a, ls1046a
+
+Optional properties:
+ - little-endian : RCPM register block is Little Endian. Without it RCPM
+   will be Big Endian (default case).
 
 Example:
 The RCPM node for T4240:
 	rcpm: global-utilities@e2000 {
 		compatible = "fsl,t4240-rcpm", "fsl,qoriq-rcpm-2.0";
 		reg = <0xe2000 0x1000>;
-		fsl,#rcpm-wakeup-cells = <2>;
+		#fsl,rcpm-wakeup-cells = <2>;
 	};
 
 * Freescale RCPM Wakeup Source Device Tree Bindings
@@ -44,7 +50,7 @@ can be used as a wakeup source.
 
   - fsl,rcpm-wakeup: Consists of a phandle to the rcpm node and the IPPDEXPCR
 	register cells. The number of IPPDEXPCR register cells is defined in
-	"fsl,#rcpm-wakeup-cells" in the rcpm node. The first register cell is
+	"#fsl,rcpm-wakeup-cells" in the rcpm node. The first register cell is
 	the bit mask that should be set in IPPDEXPCR0, and the second register
 	cell is for IPPDEXPCR1, and so on.
 
-- 
2.7.4

Re: [PATCH v7 2/3] Documentation: dt: binding: fsl: Add 'little-endian' and update Chassis define

[Scott Wood]

On Mon, 2019-10-21 at 11:49 +0800, Ran Wang wrote:
> By default, QorIQ SoC's RCPM register block is Big Endian. But
> there are some exceptions, such as LS1088A and LS2088A, are
> Little Endian. So add this optional property to help identify
> them.
> 
> Actually LS2021A and other Layerscapes won't totally follow Chassis
> 2.1, so separate them from powerpc SoC.

Did you mean LS1021A and "don't" instead of "won't", given the change to the
examples?

> Change in v5:
> 	- Add 'Reviewed-by: Rob Herring <robh@kernel.org>' to commit message.
> 	- Rename property 'fsl,#rcpm-wakeup-cells' to '#fsl,rcpm-wakeup-
> cells'.
> 	please see https://lore.kernel.org/patchwork/patch/1101022/

I'm not sure why Rob considers this the "correct form" -- there are other
examples of the current form, such as ibm,#dma-address-cells and ti,#tlb-
entries, and the current form makes more logical sense (# is part of the
property name, not the vendor).  Oh well.

> Required properites:
>    - reg : Offset and length of the register set of the RCPM block.
> -  - fsl,#rcpm-wakeup-cells : The number of IPPDEXPCR register cells in the
> +  - #fsl,rcpm-wakeup-cells : The number of IPPDEXPCR register cells in the
>  	fsl,rcpm-wakeup property.
>    - compatible : Must contain a chip-specific RCPM block compatible string
>  	and (if applicable) may contain a chassis-version RCPM compatible
> @@ -20,6 +20,7 @@ Required properites:
>  	* "fsl,qoriq-rcpm-1.0": for chassis 1.0 rcpm
>  	* "fsl,qoriq-rcpm-2.0": for chassis 2.0 rcpm
>  	* "fsl,qoriq-rcpm-2.1": for chassis 2.1 rcpm
> +	* "fsl,qoriq-rcpm-2.1+": for chassis 2.1+ rcpm

Is there something actually called "2.1+"?  It looks a bit like an attempt to
claim compatibility with all future versions.  If the former, is it a name
that comes from the hardware side with an intent for it to describe a stable
interface, or are we later going to see a patch changing some by-then-existing 
device trees from "2.1+" to "2.1++" when some new incompatibility is found?

Perhaps it would be better to bind to the specific chip compatibles.

-Scott

RE: [PATCH v7 2/3] Documentation: dt: binding: fsl: Add 'little-endian' and update Chassis define

[Ran Wang]

Hi Scott,

On Friday, October 25, 2019 02:34, Scott Wood wrote
> 
> On Mon, 2019-10-21 at 11:49 +0800, Ran Wang wrote:
> > By default, QorIQ SoC's RCPM register block is Big Endian. But there
> > are some exceptions, such as LS1088A and LS2088A, are Little Endian.
> > So add this optional property to help identify them.
> >
> > Actually LS2021A and other Layerscapes won't totally follow Chassis
> > 2.1, so separate them from powerpc SoC.
> 
> Did you mean LS1021A and "don't" instead of "won't", given the change to the
> examples?

OK, I will change it to don't to just tel current situation.
 
> > Change in v5:
> > 	- Add 'Reviewed-by: Rob Herring <robh@kernel.org>' to commit
> message.
> > 	- Rename property 'fsl,#rcpm-wakeup-cells' to '#fsl,rcpm-wakeup-
> > cells'.
> > 	please see https://lore.kernel.org/patchwork/patch/1101022/
> 
> I'm not sure why Rob considers this the "correct form" -- there are other
> examples of the current form, such as ibm,#dma-address-cells and ti,#tlb-
> entries, and the current form makes more logical sense (# is part of the property
> name, not the vendor).  Oh well.
> 
> > Required properites:
> >    - reg : Offset and length of the register set of the RCPM block.
> > -  - fsl,#rcpm-wakeup-cells : The number of IPPDEXPCR register cells
> > in the
> > +  - #fsl,rcpm-wakeup-cells : The number of IPPDEXPCR register cells
> > + in the
> >  	fsl,rcpm-wakeup property.
> >    - compatible : Must contain a chip-specific RCPM block compatible string
> >  	and (if applicable) may contain a chassis-version RCPM compatible @@
> > -20,6 +20,7 @@ Required properites:
> >  	* "fsl,qoriq-rcpm-1.0": for chassis 1.0 rcpm
> >  	* "fsl,qoriq-rcpm-2.0": for chassis 2.0 rcpm
> >  	* "fsl,qoriq-rcpm-2.1": for chassis 2.1 rcpm
> > +	* "fsl,qoriq-rcpm-2.1+": for chassis 2.1+ rcpm
> 
> Is there something actually called "2.1+"?  It looks a bit like an attempt to claim
> compatibility with all future versions.  If the former, is it a name that comes
> from the hardware side with an intent for it to describe a stable interface, or are
> we later going to see a patch changing some by-then-existing device trees from
> "2.1+" to "2.1++" when some new incompatibility is found?
>
> Perhaps it would be better to bind to the specific chip compatibles.

According to SoC data sheets, powerPC SoC T1040 and current ARM based Layerscape
SoCs (LS1021A, LS1012A, LS1043A, etc)'s arch designs are both basing on Chassis spec 2.1.
However, for Layerscape, their data sheets are also explicitly telling that some minor
changes have been made(basing on Chassis 2.1 spec). And in parallel, the SW arch designs
between T1040 and Layerscape family are also different: For Layerscape, part of RCPM
programming job has been moved from kernel driver to firmware/bootloader (through
PSCI interface). That's why I have to name a new compatible string to distinguish them.
They cannot use the same driver. I don’t think we will add another sting like 2.1++ in the
future. If the Chassis spec keep evolving and requiring different programming logic,
we can add more like 3.0, 4.0, ..., I think.

Regards,
Ran 

[PATCH v7 3/3] soc: fsl: add RCPM driver

[Ran Wang]

The NXP's QorIQ Processors based on ARM Core have RCPM module
(Run Control and Power Management), which performs system level
tasks associated with power management such as wakeup source control.

This driver depends on PM wakeup source framework which help to
collect wake information.

Signed-off-by: Ran Wang <ran.wang_1@nxp.com>
---
Change in v7:
	- Replace 'ws->dev' with 'ws->dev->parent' to get aligned with
	c8377adfa781 ("PM / wakeup: Show wakeup sources stats in sysfs")
	- Remove '+obj-y += ftm_alarm.o' since it is wrong.
	- Cosmetic work.

Change in v6:
	- Adjust related API usage to meet wakeup.c's update in patch 1/3.

Change in v5:
	- Fix v4 regression of the return value of wakeup_source_get_next()
	didn't pass to ws in while loop.
	- Rename wakeup_source member 'attached_dev' to 'dev'.
	- Rename property 'fsl,#rcpm-wakeup-cells' to '#fsl,rcpm-wakeup-cells'.
	please see https://lore.kernel.org/patchwork/patch/1101022/

Change in v4:
	- Remove extra ',' in author line of rcpm.c
	- Update usage of wakeup_source_get_next() to be less confusing to the
reader, code logic remain the same.

Change in v3:
	- Some whitespace ajdustment.

Change in v2:
	- Rebase Kconfig and Makefile update to latest mainline.

 drivers/soc/fsl/Kconfig  |   8 +++
 drivers/soc/fsl/Makefile |   1 +
 drivers/soc/fsl/rcpm.c   | 132 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 141 insertions(+)
 create mode 100644 drivers/soc/fsl/rcpm.c

diff --git a/drivers/soc/fsl/Kconfig b/drivers/soc/fsl/Kconfig
index f9ad8ad..4918856 100644
--- a/drivers/soc/fsl/Kconfig
+++ b/drivers/soc/fsl/Kconfig
@@ -40,4 +40,12 @@ config DPAA2_CONSOLE
 	  /dev/dpaa2_mc_console and /dev/dpaa2_aiop_console,
 	  which can be used to dump the Management Complex and AIOP
 	  firmware logs.
+
+config FSL_RCPM
+	bool "Freescale RCPM support"
+	depends on PM_SLEEP
+	help
+	  The NXP QorIQ Processors based on ARM Core have RCPM module
+	  (Run Control and Power Management), which performs all device-level
+	  tasks associated with power management, such as wakeup source control.
 endmenu
diff --git a/drivers/soc/fsl/Makefile b/drivers/soc/fsl/Makefile
index 71dee8d..906f1cd 100644
--- a/drivers/soc/fsl/Makefile
+++ b/drivers/soc/fsl/Makefile
@@ -6,6 +6,7 @@
 obj-$(CONFIG_FSL_DPAA)                 += qbman/
 obj-$(CONFIG_QUICC_ENGINE)		+= qe/
 obj-$(CONFIG_CPM)			+= qe/
+obj-$(CONFIG_FSL_RCPM)			+= rcpm.o
 obj-$(CONFIG_FSL_GUTS)			+= guts.o
 obj-$(CONFIG_FSL_MC_DPIO) 		+= dpio/
 obj-$(CONFIG_DPAA2_CONSOLE)		+= dpaa2-console.o
diff --git a/drivers/soc/fsl/rcpm.c b/drivers/soc/fsl/rcpm.c
new file mode 100644
index 0000000..3da9fc3
--- /dev/null
+++ b/drivers/soc/fsl/rcpm.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// rcpm.c - Freescale QorIQ RCPM driver
+//
+// Copyright 2019 NXP
+//
+// Author: Ran Wang <ran.wang_1@nxp.com>
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+#include <linux/kernel.h>
+
+#define RCPM_WAKEUP_CELL_MAX_SIZE	7
+
+struct rcpm {
+	unsigned int	wakeup_cells;
+	void __iomem	*ippdexpcr_base;
+	bool		little_endian;
+};
+
+static int rcpm_pm_prepare(struct device *dev)
+{
+	int i, ret, idx;
+	void __iomem *base;
+	struct wakeup_source	*ws;
+	struct rcpm		*rcpm;
+	struct device_node	*np = dev->of_node;
+	u32 value[RCPM_WAKEUP_CELL_MAX_SIZE + 1], tmp;
+
+	rcpm = dev_get_drvdata(dev);
+	if (!rcpm)
+		return -EINVAL;
+
+	base = rcpm->ippdexpcr_base;
+
+	/* Begin with first registered wakeup source */
+	ws = wakeup_source_get_start(&idx);
+	do {
+		/* skip object which is not attached to device */
+		if (!ws->dev->parent)
+			continue;
+
+		ret = device_property_read_u32_array(ws->dev->parent,
+				"fsl,rcpm-wakeup", value,
+				rcpm->wakeup_cells + 1);
+
+		/*  Wakeup source should refer to current rcpm device */
+		if (ret || (np->phandle != value[0])) {
+			dev_info(dev, "%s doesn't refer to this rcpm\n",
+					ws->name);
+			continue;
+		}
+
+		for (i = 0; i < rcpm->wakeup_cells; i++) {
+			/* We can only OR related bits */
+			if (value[i + 1]) {
+				if (rcpm->little_endian) {
+					tmp = ioread32(base + i * 4);
+					tmp |= value[i + 1];
+					iowrite32(tmp, base + i * 4);
+				} else {
+					tmp = ioread32be(base + i * 4);
+					tmp |= value[i + 1];
+					iowrite32be(tmp, base + i * 4);
+				}
+			}
+		}
+	} while (ws = wakeup_source_get_next(ws));
+
+	wakeup_source_get_stop(idx);
+
+	return 0;
+}
+
+static const struct dev_pm_ops rcpm_pm_ops = {
+	.prepare =  rcpm_pm_prepare,
+};
+
+static int rcpm_probe(struct platform_device *pdev)
+{
+	struct device	*dev = &pdev->dev;
+	struct resource *r;
+	struct rcpm	*rcpm;
+	int ret;
+
+	rcpm = devm_kzalloc(dev, sizeof(*rcpm), GFP_KERNEL);
+	if (!rcpm)
+		return -ENOMEM;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r)
+		return -ENODEV;
+
+	rcpm->ippdexpcr_base = devm_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(rcpm->ippdexpcr_base)) {
+		ret =  PTR_ERR(rcpm->ippdexpcr_base);
+		return ret;
+	}
+
+	rcpm->little_endian = device_property_read_bool(
+			&pdev->dev, "little-endian");
+
+	ret = device_property_read_u32(&pdev->dev,
+			"#fsl,rcpm-wakeup-cells", &rcpm->wakeup_cells);
+	if (ret)
+		return ret;
+
+	dev_set_drvdata(&pdev->dev, rcpm);
+
+	return 0;
+}
+
+static const struct of_device_id rcpm_of_match[] = {
+	{ .compatible = "fsl,qoriq-rcpm-2.1+", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, rcpm_of_match);
+
+static struct platform_driver rcpm_driver = {
+	.driver = {
+		.name = "rcpm",
+		.of_match_table = rcpm_of_match,
+		.pm	= &rcpm_pm_ops,
+	},
+	.probe = rcpm_probe,
+};
+
+module_platform_driver(rcpm_driver);
-- 
2.7.4

Re: [PATCH v7 3/3] soc: fsl: add RCPM driver

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 3182 bytes --]

Hi Ran,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[cannot apply to v5.4-rc4 next-20191023]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Ran-Wang/PM-wakeup-Add-routine-to-help-fetch-wakeup-source-object/20191024-101743
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 13b86bc4cd648eae69fdcf3d04b2750c76350053
config: mips-allmodconfig (attached as .config)
compiler: mips-linux-gcc (GCC) 7.4.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.4.0 make.cross ARCH=mips 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   drivers/soc/fsl/rcpm.c: In function 'rcpm_pm_prepare':
>> drivers/soc/fsl/rcpm.c:72:11: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
     } while (ws = wakeup_source_get_next(ws));
              ^~

vim +72 drivers/soc/fsl/rcpm.c

    24	
    25	static int rcpm_pm_prepare(struct device *dev)
    26	{
    27		int i, ret, idx;
    28		void __iomem *base;
    29		struct wakeup_source	*ws;
    30		struct rcpm		*rcpm;
    31		struct device_node	*np = dev->of_node;
    32		u32 value[RCPM_WAKEUP_CELL_MAX_SIZE + 1], tmp;
    33	
    34		rcpm = dev_get_drvdata(dev);
    35		if (!rcpm)
    36			return -EINVAL;
    37	
    38		base = rcpm->ippdexpcr_base;
    39	
    40		/* Begin with first registered wakeup source */
    41		ws = wakeup_source_get_start(&idx);
    42		do {
    43			/* skip object which is not attached to device */
    44			if (!ws->dev->parent)
    45				continue;
    46	
    47			ret = device_property_read_u32_array(ws->dev->parent,
    48					"fsl,rcpm-wakeup", value,
    49					rcpm->wakeup_cells + 1);
    50	
    51			/*  Wakeup source should refer to current rcpm device */
    52			if (ret || (np->phandle != value[0])) {
    53				dev_info(dev, "%s doesn't refer to this rcpm\n",
    54						ws->name);
    55				continue;
    56			}
    57	
    58			for (i = 0; i < rcpm->wakeup_cells; i++) {
    59				/* We can only OR related bits */
    60				if (value[i + 1]) {
    61					if (rcpm->little_endian) {
    62						tmp = ioread32(base + i * 4);
    63						tmp |= value[i + 1];
    64						iowrite32(tmp, base + i * 4);
    65					} else {
    66						tmp = ioread32be(base + i * 4);
    67						tmp |= value[i + 1];
    68						iowrite32be(tmp, base + i * 4);
    69					}
    70				}
    71			}
  > 72		} while (ws = wakeup_source_get_next(ws));
    73	
    74		wakeup_source_get_stop(idx);
    75	
    76		return 0;
    77	}
    78	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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Re: [PATCH v7 1/3] PM: wakeup: Add routine to help fetch wakeup source object.

[Rafael J. Wysocki]

On Mon, Oct 21, 2019 at 5:49 AM Ran Wang <ran.wang_1@nxp.com> wrote:
>
> Some user might want to go through all registered wakeup sources
> and doing things accordingly. For example, SoC PM driver might need to
> do HW programming to prevent powering down specific IP which wakeup
> source depending on. So add this API to help walk through all registered
> wakeup source objects on that list and return them one by one.
>
> Signed-off-by: Ran Wang <ran.wang_1@nxp.com>
> Tested-by: Leonard Crestez <leonard.crestez@nxp.com>
> ---
> Change in v7:
>         - Remove define of member *dev in wake_irq to fix conflict with commit
>         c8377adfa781 ("PM / wakeup: Show wakeup sources stats in sysfs"), user
>         will use ws->dev->parent instead.
>         - Remove '#include <linux/of_device.h>' because it is not used.
>
> Change in v6:
>         - Add wakeup_source_get_star() and wakeup_source_get_stop() to aligned
>         with wakeup_sources_stats_seq_start/nex/stop.
>
> Change in v5:
>         - Update commit message, add decription of walk through all wakeup
>         source objects.
>         - Add SCU protection in function wakeup_source_get_next().
>         - Rename wakeup_source member 'attached_dev' to 'dev' and move it up
>         (before wakeirq).
>
> Change in v4:
>         - None.
>
> Change in v3:
>         - Adjust indentation of *attached_dev;.
>
> Change in v2:
>         - None.
>
>  drivers/base/power/wakeup.c | 37 +++++++++++++++++++++++++++++++++++++
>  include/linux/pm_wakeup.h   |  3 +++
>  2 files changed, 40 insertions(+)
>
> diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
> index 5817b51..dee1b09 100644
> --- a/drivers/base/power/wakeup.c
> +++ b/drivers/base/power/wakeup.c
> @@ -248,6 +248,43 @@ void wakeup_source_unregister(struct wakeup_source *ws)
>  EXPORT_SYMBOL_GPL(wakeup_source_unregister);
>
>  /**
> + * wakeup_source_get_star - Begin a walk on wakeup source list

The "get" in the name suggests acquiring a reference of some kind
which doesn't happen here.

What about renaming it to wakeup_sources_walk_start()?

> + * @srcuidx: Lock index allocated for this caller.
> + */
> +struct wakeup_source *wakeup_source_get_start(int *srcuidx)

I don't quite like the calling convention here with passing an int
pointer to get the SRCU index back.

What about splitting this into, say, wakeup_sources_read_lock() (that
will return the SRCU index) and wakeup_sources_walk_start() (that will
return the first list entry)?

Then, you could do something like

idx = wakeup_sources_read_lock();

ws = wakeup_sources_walk_start();
while (ws) {

        stuff

        ws = wakeup_sources_walk_next();
}

wakeup_sources_read_unlock(idx);

Or even define for_each_wakeup_source(ws) as

    for (ws = wakeup_sources_walk_start(); ws; ws = wakeup_sources_walk_next())

and use that under a _read_lock()/_read_unlock() pair?