[PATCH v3 0/2] power: reset: support for Atmel alternative Shutdown Controller

[PATCH v3 0/2] power: reset: support for Atmel alternative Shutdown Controller

[Nicolas Ferre]

This is a series to add driver for a new Atmel Shutdown Controller. This new IP
is extensible and some features will be added later (see the TODO section).
Its extensible nature led to write a new binding so that wake-up sources can be
described easily.

Changes in v3:
- get and use slow clock and specify its handler in binding
- add the slow clock handle as the IP uses it
- remove useless protection at the beginning of pm_power_off handler
- allow to compile it as a module
- add COMPILE_TEST directive in Kconfig
- update description in file header

Changes in v2:
- add MODULE_DEVICE_TABLE as advised by Sebastian Reichel
- review indentation and braces to correct errors pointed out by checkpatch

Nicolas Ferre (2):
  ARM: at91/dt: shdwc binding: add new shutdown controller documentation
  power: reset: at91-shdwc: add new shutdown controller driver

 .../devicetree/bindings/arm/atmel-at91.txt         |  54 ++++
 drivers/power/reset/Kconfig                        |   8 +
 drivers/power/reset/Makefile                       |   1 +
 drivers/power/reset/at91-shdwc.c                   | 288 +++++++++++++++++++++
 4 files changed, 351 insertions(+)
 create mode 100644 drivers/power/reset/at91-shdwc.c

-- 
2.1.3

[PATCH v3 1/2] ARM: at91/dt: shdwc binding: add new shutdown controller documentation

[Nicolas Ferre]

The new shutdown controller compatible with sama5d2 has a new binding
documentation and properties.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---

Changes in v3:
- get and use slow clock and specify its handler in binding

Changes in v2: None

 .../devicetree/bindings/arm/atmel-at91.txt         | 54 ++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/atmel-at91.txt b/Documentation/devicetree/bindings/arm/atmel-at91.txt
index 7fd64ec9ee1d..253e573f28c4 100644
--- a/Documentation/devicetree/bindings/arm/atmel-at91.txt
+++ b/Documentation/devicetree/bindings/arm/atmel-at91.txt
@@ -147,6 +147,60 @@ Example:
 		clocks = <&clk32k>;
 	};
 
+SHDWC Shutdown Controller (Alternative)
+
+1) shdwc node
+
+required properties:
+- compatible: should be "atmel,sama5d2-shdwc".
+- reg: should contain registers location and length
+- clocks: phandle to input clock.
+- #address-cells: should be one. The cell is the wake-up input index.
+- #size-cells: should be zero.
+
+optional properties:
+
+- atmel,wakeup-debouncer: minimum wake-up inputs debouncer period in
+  micro-seconds. It's usually a board-related property.
+- atmel,wakeup-rtc-timer: boolean to enable Real-Time Clock wake-up.
+
+The node contains child nodes for each wake-up input that the platform uses.
+
+2) input nodes
+
+Wake-up input nodes are usually described in the "board" part of the Device
+Tree. Note also that input 0 is linked to the wake-up pin and is frequently
+used.
+
+Required properties:
+- reg: should contain the wake-up input index [0 - 15].
+
+Optional properties:
+- atmel,wakeup-type: string, operation mode of the input described by the child
+  node. Supported values are: "high" or "low".
+
+Example:
+
+On the SoC side:
+	shdwc at f8048010 {
+		compatible = "atmel,sama5d2-shdwc";
+		reg = <0xf8048010 0x10>;
+		clocks = <&clk32k>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		atmel,wakeup-rtc-timer;
+	};
+
+On the board side:
+	shdwc at f8048010 {
+		atmel,shdwc-debouncer = <976>;
+
+		input at 0 {
+			reg = <0>;
+			atmel,wakeup-type = "low";
+		};
+	};
+
 Special Function Registers (SFR)
 
 Special Function Registers (SFR) manage specific aspects of the integrated
-- 
2.1.3

[PATCH v3 1/2] ARM: at91/dt: shdwc binding: add new shutdown controller documentation

[Alexandre Belloni]

On 30/09/2015 at 18:22:00 +0200, Nicolas Ferre wrote :
> +SHDWC Shutdown Controller (Alternative)
> +
> +1) shdwc node
> +
> +required properties:
> +- compatible: should be "atmel,sama5d2-shdwc".
> +- reg: should contain registers location and length
> +- clocks: phandle to input clock.
> +- #address-cells: should be one. The cell is the wake-up input index.
> +- #size-cells: should be zero.
> +
> +optional properties:
> +
> +- atmel,wakeup-debouncer: minimum wake-up inputs debouncer period in

Shouldn't that property be called atmel,wakeup-debouncer-ms ?

> +
> +2) input nodes
> +
> +Wake-up input nodes are usually described in the "board" part of the Device
> +Tree. Note also that input 0 is linked to the wake-up pin and is frequently
> +used.
> +
> +Required properties:
> +- reg: should contain the wake-up input index [0 - 15].
> +
> +Optional properties:
> +- atmel,wakeup-type: string, operation mode of the input described by the child
> +  node. Supported values are: "high" or "low".
> +

Maybe we could avoid parsing string and use an integer with a few defines

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[PATCH v3 1/2] ARM: at91/dt: shdwc binding: add new shutdown controller documentation

[Nicolas Ferre]

Le 03/10/2015 19:02, Alexandre Belloni a ?crit :
> On 30/09/2015 at 18:22:00 +0200, Nicolas Ferre wrote :
>> +SHDWC Shutdown Controller (Alternative)
>> +
>> +1) shdwc node
>> +
>> +required properties:
>> +- compatible: should be "atmel,sama5d2-shdwc".
>> +- reg: should contain registers location and length
>> +- clocks: phandle to input clock.
>> +- #address-cells: should be one. The cell is the wake-up input index.
>> +- #size-cells: should be zero.
>> +
>> +optional properties:
>> +
>> +- atmel,wakeup-debouncer: minimum wake-up inputs debouncer period in
> 
> Shouldn't that property be called atmel,wakeup-debouncer-ms ?

Well, as it's microseconds, it should be "-us", according to the file:
Documentation/devicetree/bindings/property-units.txt.

Reworking on this I realised that a kind "generic" property exists for
this type: "debounce-delay-ms", without a vendor prefix.

So, for the DT people, what do you think if I change my private property
to this one that seems to be used in a bunch of bindings already in its
milliseconds variant:
gpio-matrix-keypad.txt, tc3589x.txt, extcon-palmas.txt or with a vendor
prefix in nvidia,tegra20-kbc.txt or lpc32xx-key.txt

and if I diversify it to a "debounce-delay-us" variant and use it in
this driver?

>> +
>> +2) input nodes
>> +
>> +Wake-up input nodes are usually described in the "board" part of the Device
>> +Tree. Note also that input 0 is linked to the wake-up pin and is frequently
>> +used.
>> +
>> +Required properties:
>> +- reg: should contain the wake-up input index [0 - 15].
>> +
>> +Optional properties:
>> +- atmel,wakeup-type: string, operation mode of the input described by the child
>> +  node. Supported values are: "high" or "low".
>> +
> 
> Maybe we could avoid parsing string and use an integer with a few defines

Yes, even a boolean should do the trick. What about:

- atmel,wakeup-active-high: boolean, the corresponding wake-up
  input described by the child, forces the wake-up of the core power
  supply on a high level. The default is to be active low.

Thanks for your insights. Best regards,
-- 
Nicolas Ferre

[PATCH v3 2/2] power: reset: at91-shdwc: add new shutdown controller driver

[Nicolas Ferre]

Sama5d2 SoC has a completely new shutdown controller with new features and
register layout. It thus makes sense to add a new driver for this new
peripheral.

This driver is Device Tree only and handles events from the wake-up pin and
the RTC.
As the register layout may change in the future, so some values are encoded
in a configuration structure.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---

Changes in v3:
- add the slow clock handle as the IP uses it
- remove useless protection at the beginning of pm_power_off handler
- allow to compile it as a module
- add COMPILE_TEST directive in Kconfig
- update description in file header

Changes in v2:
- add MODULE_DEVICE_TABLE as advised by Sebastian Reichel
- review indentation and braces to correct errors pointed out by checkpatch

 drivers/power/reset/Kconfig      |   8 ++
 drivers/power/reset/Makefile     |   1 +
 drivers/power/reset/at91-shdwc.c | 288 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 297 insertions(+)
 create mode 100644 drivers/power/reset/at91-shdwc.c

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 1131cf75acc6..c989ffae7143 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -30,6 +30,14 @@ config POWER_RESET_AT91_RESET
 	  This driver supports restart for Atmel AT91SAM9 and SAMA5
 	  SoCs
 
+config POWER_RESET_AT91_SHDWC
+	tristate "Atmel AT91 shutdown controller driver"
+	depends on ARCH_AT91 || COMPILE_TEST
+	default SOC_SAMA5
+	help
+	  This driver supports the alternate shutdown controller for some Atmel
+	  SAMA5 SoCs. It is present for example on SAMA5D2 SoC.
+
 config POWER_RESET_AXXIA
 	bool "LSI Axxia reset driver"
 	depends on ARCH_AXXIA
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 096fa67047f6..6b9020ed3fb7 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -1,6 +1,7 @@
 obj-$(CONFIG_POWER_RESET_AS3722) += as3722-poweroff.o
 obj-$(CONFIG_POWER_RESET_AT91_POWEROFF) += at91-poweroff.o
 obj-$(CONFIG_POWER_RESET_AT91_RESET) += at91-reset.o
+obj-$(CONFIG_POWER_RESET_AT91_SHDWC) += at91-shdwc.o
 obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o
 obj-$(CONFIG_POWER_RESET_BRCMSTB) += brcmstb-reboot.o
 obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
diff --git a/drivers/power/reset/at91-shdwc.c b/drivers/power/reset/at91-shdwc.c
new file mode 100644
index 000000000000..9163ebde9f14
--- /dev/null
+++ b/drivers/power/reset/at91-shdwc.c
@@ -0,0 +1,288 @@
+/*
+ * Atmel alternative Shutdown Controller (SHDWC) driver.
+ * Found on some SoCs as the sama5d2 for instance.
+ *
+ * Copyright (C) 2015 Atmel Corporation,
+ *                    Nicolas Ferre <nicolas.ferre@atmel.com>
+ *
+ * Evolved from driver at91-poweroff.c.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * TODO:
+ * - addition to status of other wake-up inputs [1 - 15]
+ * - Analog Comparator wake-up alarm
+ * - Serial RX wake-up alarm
+ * - low power debouncer
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+
+#define SLOW_CLOCK_FREQ	32768
+
+#define AT91_SHDW_CR	0x00		/* Shut Down Control Register */
+#define AT91_SHDW_SHDW		BIT(0)			/* Shut Down command */
+#define AT91_SHDW_KEY		(0xa5 << 24)		/* KEY Password */
+
+#define AT91_SHDW_MR	0x04		/* Shut Down Mode Register */
+#define AT91_SHDW_WKUPDBC_SHIFT	24
+#define AT91_SHDW_WKUPDBC_MASK	GENMASK(31, 16)
+#define AT91_SHDW_WKUPDBC(x)	(((x) << AT91_SHDW_WKUPDBC_SHIFT) \
+						& AT91_SHDW_WKUPDBC_MASK)
+
+#define AT91_SHDW_SR	0x08		/* Shut Down Status Register */
+#define AT91_SHDW_WKUPIS_SHIFT	16
+#define AT91_SHDW_WKUPIS_MASK	GENMASK(31, 16)
+#define AT91_SHDW_WKUPIS(x)	((1 << (x)) << AT91_SHDW_WKUPIS_SHIFT \
+						& AT91_SHDW_WKUPIS_MASK)
+
+#define AT91_SHDW_WUIR	0x0c		/* Shutdown Wake-up Inputs Register */
+#define AT91_SHDW_WKUPEN_MASK	GENMASK(15, 0)
+#define AT91_SHDW_WKUPEN(x)	((1 << (x)) & AT91_SHDW_WKUPEN_MASK)
+#define AT91_SHDW_WKUPT_SHIFT	16
+#define AT91_SHDW_WKUPT_MASK	GENMASK(31, 16)
+#define AT91_SHDW_WKUPT(x)	((1 << (x)) << AT91_SHDW_WKUPT_SHIFT \
+						& AT91_SHDW_WKUPT_MASK)
+
+#define SHDW_WK_PIN(reg, cfg)	((reg) & AT91_SHDW_WKUPIS((cfg)->wkup_pin_input))
+#define SHDW_RTCWK(reg, cfg)	(((reg) >> ((cfg)->sr_rtcwk_shift)) & 0x1)
+#define SHDW_RTCWKEN(cfg)	(1 << ((cfg)->mr_rtcwk_shift))
+
+#define DBC_PERIOD_US(x)	DIV_ROUND_UP_ULL((1000000 * (x)), \
+							SLOW_CLOCK_FREQ)
+
+struct shdwc_config {
+	u8 wkup_pin_input;
+	u8 mr_rtcwk_shift;
+	u8 sr_rtcwk_shift;
+};
+
+struct shdwc {
+	struct shdwc_config *cfg;
+	void __iomem *at91_shdwc_base;
+};
+
+/*
+ * Hold configuration here, cannot be more than one instance of the driver
+ * since pm_power_off itself is global.
+ */
+static struct shdwc *at91_shdwc;
+static struct clk *sclk;
+
+static const unsigned long long sdwc_dbc_period[] = {
+	0, 3, 32, 512, 4096, 32768,
+};
+
+static void __init at91_wakeup_status(struct platform_device *pdev)
+{
+	struct shdwc *shdw = platform_get_drvdata(pdev);
+	u32 reg;
+	char *reason = "unknown";
+
+	reg = readl(shdw->at91_shdwc_base + AT91_SHDW_SR);
+
+	dev_dbg(&pdev->dev, "%s: status = %#x\n", __func__, reg);
+
+	/* Simple power-on, just bail out */
+	if (!reg)
+		return;
+
+	if (SHDW_WK_PIN(reg, shdw->cfg))
+		reason = "WKUP pin";
+	else if (SHDW_RTCWK(reg, shdw->cfg))
+		reason = "RTC";
+
+	pr_info("AT91: Wake-Up source: %s\n", reason);
+}
+
+static void at91_poweroff(void)
+{
+	writel(AT91_SHDW_KEY | AT91_SHDW_SHDW,
+			at91_shdwc->at91_shdwc_base + AT91_SHDW_CR);
+}
+
+static u32 at91_shdwc_debouncer_value(struct platform_device *pdev,
+				      u32 in_period_us)
+{
+	int i;
+	int max_idx = ARRAY_SIZE(sdwc_dbc_period) - 1;
+	unsigned long long period_us;
+	unsigned long long max_period_us = DBC_PERIOD_US(sdwc_dbc_period[max_idx]);
+
+	if (in_period_us > max_period_us) {
+		dev_warn(&pdev->dev,
+			 "debouncer period %u too big, reduced to %llu us\n",
+			 in_period_us, max_period_us);
+		return max_idx;
+	}
+
+	for (i = max_idx - 1; i > 0; i--) {
+		period_us = DBC_PERIOD_US(sdwc_dbc_period[i]);
+		dev_dbg(&pdev->dev, "%s: ref[%d] = %llu\n",
+						__func__, i, period_us);
+		if (in_period_us > period_us)
+			break;
+	}
+
+	return i + 1;
+}
+
+static u32 at91_shdwc_get_wakeup_input(struct platform_device *pdev,
+				       struct device_node *np)
+{
+	struct device_node *cnp;
+	const char *pm;
+	u32 wk_input_mask;
+	u32 wuir = 0;
+	u32 wk_input;
+
+	for_each_child_of_node(np, cnp) {
+		if (of_property_read_u32(cnp, "reg", &wk_input)) {
+			dev_warn(&pdev->dev, "reg property is missing for %s\n",
+				 cnp->full_name);
+			continue;
+		}
+
+		wk_input_mask = 1 << wk_input;
+		if (!(wk_input_mask & AT91_SHDW_WKUPEN_MASK)) {
+			dev_warn(&pdev->dev,
+				 "wake-up input %d out of bounds ignore\n",
+				 wk_input);
+			continue;
+		}
+		wuir |= wk_input_mask;
+
+		if (!of_property_read_string(cnp, "atmel,wakeup-type", &pm)) {
+			if (!strcasecmp(pm, "high"))
+				/*
+				 * only add a type if "high" is specified. Low
+				 * is the default.
+				 */
+				wuir |= AT91_SHDW_WKUPT(wk_input);
+		}
+		dev_dbg(&pdev->dev, "%s: (child %d) wuir = %#x\n",
+						__func__, wk_input, wuir);
+	}
+
+	return wuir;
+}
+
+static void at91_shdwc_dt_configure(struct platform_device *pdev)
+{
+	struct shdwc *shdw = platform_get_drvdata(pdev);
+	struct device_node *np = pdev->dev.of_node;
+	u32 mode = 0, tmp, input;
+
+	if (!np) {
+		dev_err(&pdev->dev, "device node not found\n");
+		return;
+	}
+
+	if (!of_property_read_u32(np, "atmel,shdwc-debouncer", &tmp))
+		mode |= AT91_SHDW_WKUPDBC(at91_shdwc_debouncer_value(pdev, tmp));
+
+	if (of_property_read_bool(np, "atmel,wakeup-rtc-timer"))
+		mode |= SHDW_RTCWKEN(shdw->cfg);
+
+	dev_dbg(&pdev->dev, "%s: mode = %#x\n", __func__, mode);
+	writel(mode, shdw->at91_shdwc_base + AT91_SHDW_MR);
+
+	input = at91_shdwc_get_wakeup_input(pdev, np);
+	writel(input, shdw->at91_shdwc_base + AT91_SHDW_WUIR);
+}
+
+static const struct shdwc_config sama5d2_shdwc_config = {
+	.wkup_pin_input = 0,
+	.mr_rtcwk_shift = 17,
+	.sr_rtcwk_shift = 5,
+};
+
+static const struct of_device_id at91_shdwc_of_match[] = {
+	{
+		.compatible = "atmel,sama5d2-shdwc",
+		.data = &sama5d2_shdwc_config,
+	}, {
+		/*sentinel*/
+	}
+};
+MODULE_DEVICE_TABLE(of, at91_shdwc_of_match);
+
+static int __init at91_shdwc_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	const struct of_device_id *match;
+	int ret;
+
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	at91_shdwc = devm_kzalloc(&pdev->dev, sizeof(*at91_shdwc), GFP_KERNEL);
+	if (!at91_shdwc)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, at91_shdwc);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	at91_shdwc->at91_shdwc_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(at91_shdwc->at91_shdwc_base)) {
+		dev_err(&pdev->dev, "Could not map reset controller address\n");
+		return PTR_ERR(at91_shdwc->at91_shdwc_base);
+	}
+
+	match = of_match_node(at91_shdwc_of_match, pdev->dev.of_node);
+	at91_shdwc->cfg = (struct shdwc_config *)(match->data);
+
+	sclk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sclk))
+		return PTR_ERR(sclk);
+
+	ret = clk_prepare_enable(sclk);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not enable slow clock\n");
+		return ret;
+	}
+
+	at91_wakeup_status(pdev);
+
+	at91_shdwc_dt_configure(pdev);
+
+	pm_power_off = at91_poweroff;
+
+	return 0;
+}
+
+static int __exit at91_shdwc_remove(struct platform_device *pdev)
+{
+	struct shdwc *shdw = platform_get_drvdata(pdev);
+
+	if (pm_power_off == at91_poweroff)
+		pm_power_off = NULL;
+
+	/* Reset values to disable wake-up features  */
+	writel(0, shdw->at91_shdwc_base + AT91_SHDW_MR);
+	writel(0, shdw->at91_shdwc_base + AT91_SHDW_WUIR);
+
+	clk_disable_unprepare(sclk);
+
+	return 0;
+}
+
+static struct platform_driver at91_shdwc_driver = {
+	.remove = __exit_p(at91_shdwc_remove),
+	.driver = {
+		.name = "at91-shdwc",
+		.of_match_table = at91_shdwc_of_match,
+	},
+};
+module_platform_driver_probe(at91_shdwc_driver, at91_shdwc_probe);
+
+MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
+MODULE_DESCRIPTION("Atmel shutdown controller driver");
+MODULE_LICENSE("GPL v2");
-- 
2.1.3

[PATCH v3 2/2] power: reset: at91-shdwc: add new shutdown controller driver

[kbuild test robot]

Hi Nicolas,

[auto build test results on v4.3-rc3 -- if it's inappropriate base, please ignore]

config: x86_64-allmodconfig (attached as .config)
reproduce:
  git checkout c2df3a7df512b1d640247d7c9b7542217bfb9ab1
  # save the attached .config to linux build tree
  make ARCH=x86_64 

All warnings (new ones prefixed by >>):

   drivers/power/reset/at91-shdwc.c: In function 'at91_poweroff':
>> drivers/power/reset/at91-shdwc.c:32:24: warning: large integer implicitly truncated to unsigned type [-Woverflow]
    #define AT91_SHDW_KEY  (0xa5 << 24)  /* KEY Password */
                           ^
>> drivers/power/reset/at91-shdwc.c:107:9: note: in expansion of macro 'AT91_SHDW_KEY'
     writel(AT91_SHDW_KEY | AT91_SHDW_SHDW,
            ^

vim +32 drivers/power/reset/at91-shdwc.c

    26	#include <linux/printk.h>
    27	
    28	#define SLOW_CLOCK_FREQ	32768
    29	
    30	#define AT91_SHDW_CR	0x00		/* Shut Down Control Register */
    31	#define AT91_SHDW_SHDW		BIT(0)			/* Shut Down command */
  > 32	#define AT91_SHDW_KEY		(0xa5 << 24)		/* KEY Password */
    33	
    34	#define AT91_SHDW_MR	0x04		/* Shut Down Mode Register */
    35	#define AT91_SHDW_WKUPDBC_SHIFT	24
    36	#define AT91_SHDW_WKUPDBC_MASK	GENMASK(31, 16)
    37	#define AT91_SHDW_WKUPDBC(x)	(((x) << AT91_SHDW_WKUPDBC_SHIFT) \
    38							& AT91_SHDW_WKUPDBC_MASK)
    39	
    40	#define AT91_SHDW_SR	0x08		/* Shut Down Status Register */
    41	#define AT91_SHDW_WKUPIS_SHIFT	16
    42	#define AT91_SHDW_WKUPIS_MASK	GENMASK(31, 16)
    43	#define AT91_SHDW_WKUPIS(x)	((1 << (x)) << AT91_SHDW_WKUPIS_SHIFT \
    44							& AT91_SHDW_WKUPIS_MASK)
    45	
    46	#define AT91_SHDW_WUIR	0x0c		/* Shutdown Wake-up Inputs Register */
    47	#define AT91_SHDW_WKUPEN_MASK	GENMASK(15, 0)
    48	#define AT91_SHDW_WKUPEN(x)	((1 << (x)) & AT91_SHDW_WKUPEN_MASK)
    49	#define AT91_SHDW_WKUPT_SHIFT	16
    50	#define AT91_SHDW_WKUPT_MASK	GENMASK(31, 16)
    51	#define AT91_SHDW_WKUPT(x)	((1 << (x)) << AT91_SHDW_WKUPT_SHIFT \
    52							& AT91_SHDW_WKUPT_MASK)
    53	
    54	#define SHDW_WK_PIN(reg, cfg)	((reg) & AT91_SHDW_WKUPIS((cfg)->wkup_pin_input))
    55	#define SHDW_RTCWK(reg, cfg)	(((reg) >> ((cfg)->sr_rtcwk_shift)) & 0x1)
    56	#define SHDW_RTCWKEN(cfg)	(1 << ((cfg)->mr_rtcwk_shift))
    57	
    58	#define DBC_PERIOD_US(x)	DIV_ROUND_UP_ULL((1000000 * (x)), \
    59								SLOW_CLOCK_FREQ)
    60	
    61	struct shdwc_config {
    62		u8 wkup_pin_input;
    63		u8 mr_rtcwk_shift;
    64		u8 sr_rtcwk_shift;
    65	};
    66	
    67	struct shdwc {
    68		struct shdwc_config *cfg;
    69		void __iomem *at91_shdwc_base;
    70	};
    71	
    72	/*
    73	 * Hold configuration here, cannot be more than one instance of the driver
    74	 * since pm_power_off itself is global.
    75	 */
    76	static struct shdwc *at91_shdwc;
    77	static struct clk *sclk;
    78	
    79	static const unsigned long long sdwc_dbc_period[] = {
    80		0, 3, 32, 512, 4096, 32768,
    81	};
    82	
    83	static void __init at91_wakeup_status(struct platform_device *pdev)
    84	{
    85		struct shdwc *shdw = platform_get_drvdata(pdev);
    86		u32 reg;
    87		char *reason = "unknown";
    88	
    89		reg = readl(shdw->at91_shdwc_base + AT91_SHDW_SR);
    90	
    91		dev_dbg(&pdev->dev, "%s: status = %#x\n", __func__, reg);
    92	
    93		/* Simple power-on, just bail out */
    94		if (!reg)
    95			return;
    96	
    97		if (SHDW_WK_PIN(reg, shdw->cfg))
    98			reason = "WKUP pin";
    99		else if (SHDW_RTCWK(reg, shdw->cfg))
   100			reason = "RTC";
   101	
   102		pr_info("AT91: Wake-Up source: %s\n", reason);
   103	}
   104	
   105	static void at91_poweroff(void)
   106	{
 > 107		writel(AT91_SHDW_KEY | AT91_SHDW_SHDW,
   108				at91_shdwc->at91_shdwc_base + AT91_SHDW_CR);
   109	}
   110	

---
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[PATCH v3 2/2] power: reset: at91-shdwc: add new shutdown controller driver

[kbuild test robot]

Hi Nicolas,

[auto build test results on v4.3-rc3 -- if it's inappropriate base, please ignore]

config: ia64-allmodconfig (attached as .config)
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout c2df3a7df512b1d640247d7c9b7542217bfb9ab1
        # save the attached .config to linux build tree
        make.cross ARCH=ia64 

All warnings (new ones prefixed by >>):

   In file included from include/linux/io.h:25:0,
                    from drivers/power/reset/at91-shdwc.c:22:
   drivers/power/reset/at91-shdwc.c: In function 'at91_poweroff':
   arch/ia64/include/asm/io.h:394:30: warning: large integer implicitly truncated to unsigned type [-Woverflow]
    #define writel(v,a) __writel((v), (a))
                                 ^
>> drivers/power/reset/at91-shdwc.c:107:2: note: in expansion of macro 'writel'
     writel(AT91_SHDW_KEY | AT91_SHDW_SHDW,
     ^

vim +/writel +107 drivers/power/reset/at91-shdwc.c

    16	 * - Analog Comparator wake-up alarm
    17	 * - Serial RX wake-up alarm
    18	 * - low power debouncer
    19	 */
    20	
    21	#include <linux/clk.h>
  > 22	#include <linux/io.h>
    23	#include <linux/module.h>
    24	#include <linux/of.h>
    25	#include <linux/platform_device.h>
    26	#include <linux/printk.h>
    27	
    28	#define SLOW_CLOCK_FREQ	32768
    29	
    30	#define AT91_SHDW_CR	0x00		/* Shut Down Control Register */
    31	#define AT91_SHDW_SHDW		BIT(0)			/* Shut Down command */
    32	#define AT91_SHDW_KEY		(0xa5 << 24)		/* KEY Password */
    33	
    34	#define AT91_SHDW_MR	0x04		/* Shut Down Mode Register */
    35	#define AT91_SHDW_WKUPDBC_SHIFT	24
    36	#define AT91_SHDW_WKUPDBC_MASK	GENMASK(31, 16)
    37	#define AT91_SHDW_WKUPDBC(x)	(((x) << AT91_SHDW_WKUPDBC_SHIFT) \
    38							& AT91_SHDW_WKUPDBC_MASK)
    39	
    40	#define AT91_SHDW_SR	0x08		/* Shut Down Status Register */
    41	#define AT91_SHDW_WKUPIS_SHIFT	16
    42	#define AT91_SHDW_WKUPIS_MASK	GENMASK(31, 16)
    43	#define AT91_SHDW_WKUPIS(x)	((1 << (x)) << AT91_SHDW_WKUPIS_SHIFT \
    44							& AT91_SHDW_WKUPIS_MASK)
    45	
    46	#define AT91_SHDW_WUIR	0x0c		/* Shutdown Wake-up Inputs Register */
    47	#define AT91_SHDW_WKUPEN_MASK	GENMASK(15, 0)
    48	#define AT91_SHDW_WKUPEN(x)	((1 << (x)) & AT91_SHDW_WKUPEN_MASK)
    49	#define AT91_SHDW_WKUPT_SHIFT	16
    50	#define AT91_SHDW_WKUPT_MASK	GENMASK(31, 16)
    51	#define AT91_SHDW_WKUPT(x)	((1 << (x)) << AT91_SHDW_WKUPT_SHIFT \
    52							& AT91_SHDW_WKUPT_MASK)
    53	
    54	#define SHDW_WK_PIN(reg, cfg)	((reg) & AT91_SHDW_WKUPIS((cfg)->wkup_pin_input))
    55	#define SHDW_RTCWK(reg, cfg)	(((reg) >> ((cfg)->sr_rtcwk_shift)) & 0x1)
    56	#define SHDW_RTCWKEN(cfg)	(1 << ((cfg)->mr_rtcwk_shift))
    57	
    58	#define DBC_PERIOD_US(x)	DIV_ROUND_UP_ULL((1000000 * (x)), \
    59								SLOW_CLOCK_FREQ)
    60	
    61	struct shdwc_config {
    62		u8 wkup_pin_input;
    63		u8 mr_rtcwk_shift;
    64		u8 sr_rtcwk_shift;
    65	};
    66	
    67	struct shdwc {
    68		struct shdwc_config *cfg;
    69		void __iomem *at91_shdwc_base;
    70	};
    71	
    72	/*
    73	 * Hold configuration here, cannot be more than one instance of the driver
    74	 * since pm_power_off itself is global.
    75	 */
    76	static struct shdwc *at91_shdwc;
    77	static struct clk *sclk;
    78	
    79	static const unsigned long long sdwc_dbc_period[] = {
    80		0, 3, 32, 512, 4096, 32768,
    81	};
    82	
    83	static void __init at91_wakeup_status(struct platform_device *pdev)
    84	{
    85		struct shdwc *shdw = platform_get_drvdata(pdev);
    86		u32 reg;
    87		char *reason = "unknown";
    88	
    89		reg = readl(shdw->at91_shdwc_base + AT91_SHDW_SR);
    90	
    91		dev_dbg(&pdev->dev, "%s: status = %#x\n", __func__, reg);
    92	
    93		/* Simple power-on, just bail out */
    94		if (!reg)
    95			return;
    96	
    97		if (SHDW_WK_PIN(reg, shdw->cfg))
    98			reason = "WKUP pin";
    99		else if (SHDW_RTCWK(reg, shdw->cfg))
   100			reason = "RTC";
   101	
   102		pr_info("AT91: Wake-Up source: %s\n", reason);
   103	}
   104	
   105	static void at91_poweroff(void)
   106	{
 > 107		writel(AT91_SHDW_KEY | AT91_SHDW_SHDW,
   108				at91_shdwc->at91_shdwc_base + AT91_SHDW_CR);
   109	}
   110	

---
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https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
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