[PATCH v4 0/2] power: reset: support for Atmel alternative Shutdown Controller

[PATCH v4 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 v4:
- change property to debounce-delay-us so that we can use a generic property
  and we can have the unit explicitly included it the name according to
  Documentation/devicetree/bindings/property-units.txt.
- move to atmel,wakeup-active-high boolean property instead of a "high", "low"
  string comparison.
- fix warning found by 0-day robot: large integer implicitly truncated to
  unsigned type [-Woverflow]
- add entry in MAINTAINERS file

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: dts: at91: shdwc binding: add new shutdown controller
    documentation
  power: reset: at91-shdwc: add new shutdown controller driver

 .../devicetree/bindings/arm/atmel-at91.txt         |  59 +++++
 MAINTAINERS                                        |   5 +
 drivers/power/reset/Kconfig                        |   8 +
 drivers/power/reset/Makefile                       |   1 +
 drivers/power/reset/at91-shdwc.c                   | 282 +++++++++++++++++++++
 5 files changed, 355 insertions(+)
 create mode 100644 drivers/power/reset/at91-shdwc.c

-- 
2.1.3

[PATCH v4 1/2] ARM: dts: at91: 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>
Cc: devicetree@vger.kernel.org
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
---

Changes in v4:
- change property to debounce-delay-us so that we can use a generic property
  and we can have the unit explicitly included it the name according to
  Documentation/devicetree/bindings/property-units.txt.
- move to atmel,wakeup-active-high boolean property instead of a "high", "low"
  string comparison.

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

Changes in v2: None

 .../devicetree/bindings/arm/atmel-at91.txt         | 59 ++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/atmel-at91.txt b/Documentation/devicetree/bindings/arm/atmel-at91.txt
index 7fd64ec9ee1d..cfeb161cb0ae 100644
--- a/Documentation/devicetree/bindings/arm/atmel-at91.txt
+++ b/Documentation/devicetree/bindings/arm/atmel-at91.txt
@@ -147,6 +147,65 @@ 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:
+
+- debounce-delay-us: minimum wake-up inputs debouncer period in
+  microseconds. 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-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.
+
+Example:
+
+On the SoC side:
+	shdwc@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@f8048010 {
+		debounce-delay-us = <976>;
+
+		input@0 {
+			reg = <0>;
+		};
+
+		input@1 {
+			reg = <1>;
+			atmel,wakeup-active-high;
+		};
+	};
+
 Special Function Registers (SFR)
 
 Special Function Registers (SFR) manage specific aspects of the integrated
-- 
2.1.3

[PATCH v4 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 v4:
- fix warning found by 0-day robot: large integer implicitly truncated to
  unsigned type [-Woverflow]
- move to the property debounce-delay-us
- move to atmel,wakeup-active-high boolean
- add entry in MAINTAINERS file

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

 MAINTAINERS                      |   5 +
 drivers/power/reset/Kconfig      |   8 ++
 drivers/power/reset/Makefile     |   1 +
 drivers/power/reset/at91-shdwc.c | 282 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 296 insertions(+)
 create mode 100644 drivers/power/reset/at91-shdwc.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 5744af3d79ab..afac65c0d68c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1999,6 +1999,11 @@ M:	Nicolas Ferre <nicolas.ferre@atmel.com>
 S:	Supported
 F:	drivers/tty/serial/atmel_serial.c
 
+ATMEL AT91 Alternative Shutdown Controller
+M:	Nicolas Ferre <nicolas.ferre@atmel.com>
+S:	Supported
+F:	drivers/power/reset/at91-shdwc.c
+
 ATMEL SAMA5D2 ADC DRIVER
 M:	Ludovic Desroches <ludovic.desroches@atmel.com>
 L:	linux-iio@vger.kernel.org
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 0a6408a39c66..a23109bed7bd 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..e3b7b430de8e
--- /dev/null
+++ b/drivers/power/reset/at91-shdwc.c
@@ -0,0 +1,282 @@
+/*
+ * 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		(0xa5UL << 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;
+	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_bool(cnp, "atmel,wakeup-active-high"))
+			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, "debounce-delay-us", &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

Re: [PATCH v4 2/2] power: reset: at91-shdwc: add new shutdown controller driver

[Alexandre Belloni]

On 10/03/2016 at 16:37:40 +0100, Nicolas Ferre wrote :
> +ATMEL AT91 Alternative Shutdown Controller

Can't that be sama5d2 instead of alternative?

> +M:	Nicolas Ferre <nicolas.ferre@atmel.com>
> +S:	Supported
> +F:	drivers/power/reset/at91-shdwc.c

I would also use that in the filename. Because once there is a third
shdwc, I'm not sure how you will be able to name it.

> +config POWER_RESET_AT91_SHDWC

I would also include that in the config name.

> +	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.
> +

> +#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		(0xa5UL << 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);

This is still not properly aligned :)

> +}
> +
> +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);

Alignment is not correct.

> +		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;
> +	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_bool(cnp, "atmel,wakeup-active-high"))
> +			wuir |= AT91_SHDW_WKUPT(wk_input);
> +
> +		dev_dbg(&pdev->dev, "%s: (child %d) wuir = %#x\n",
> +						__func__, wk_input, wuir);

Alignment is not correct

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

Re: [PATCH v4 2/2] power: reset: at91-shdwc: add new shutdown controller driver

[Nicolas Ferre]

Le 14/03/2016 21:22, Alexandre Belloni a écrit :
> On 10/03/2016 at 16:37:40 +0100, Nicolas Ferre wrote :
>> +ATMEL AT91 Alternative Shutdown Controller
> 
> Can't that be sama5d2 instead of alternative?
> 
>> +M:	Nicolas Ferre <nicolas.ferre@atmel.com>
>> +S:	Supported
>> +F:	drivers/power/reset/at91-shdwc.c
> 
> I would also use that in the filename. Because once there is a third
> shdwc, I'm not sure how you will be able to name it.
> 
>> +config POWER_RESET_AT91_SHDWC
> 
> I would also include that in the config name.
> 
>> +	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.
>> +
> 
>> +#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		(0xa5UL << 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);
> 
> This is still not properly aligned :)

Ok for this one.


>> +}
>> +
>> +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);
> 
> Alignment is not correct.
> 
>> +		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;
>> +	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_bool(cnp, "atmel,wakeup-active-high"))
>> +			wuir |= AT91_SHDW_WKUPT(wk_input);
>> +
>> +		dev_dbg(&pdev->dev, "%s: (child %d) wuir = %#x\n",
>> +						__func__, wk_input, wuir);
> 
> Alignment is not correct

I don't agree with you on the 2 last ones. In Documentation/CodingStyle,
it is said that:

"Chapter 2: Breaking long lines and strings
[..]
Descendants are always substantially shorter than the parent and
are placed substantially to the right."

Together with the 80 column requirement that I also fulfil, I think that
my code is well aligned.

So I keep it like this ;-)

Bye,
-- 
Nicolas Ferre

Re: [PATCH v4 2/2] power: reset: at91-shdwc: add new shutdown controller driver

[Alexandre Belloni]

On 16/03/2016 at 12:36:56 +0100, Nicolas Ferre wrote :
> I don't agree with you on the 2 last ones. In Documentation/CodingStyle,
> it is said that:
> 
> "Chapter 2: Breaking long lines and strings
> [..]
> Descendants are always substantially shorter than the parent and
> are placed substantially to the right."
> 
> Together with the 80 column requirement that I also fulfil, I think that
> my code is well aligned.
> 
> So I keep it like this ;-)
> 

checkpatch.pl --strict disagrees with you


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