[PATCH v5 0/9] mfd: watchdog: rtc: New driver for ST's LPC IP

[PATCH v5 0/9] mfd: watchdog: rtc: New driver for ST's LPC IP

[Lee Jones]

ST's Low Power Controller (LPC) controls two devices; watchdog and RTC.
Only one of the devices can be used at any one time, which is enforced
by the Device Driver model.
 
This driver set provides everything you need to choose one (and only
one) of the LPC devices to run per I/P block, of which there are two
on the enabled STiH407 h/w.

Version 5:
 - Disable WDT clock over suspend
 - GPL v2 => GPL to reflect the information in the header
 - Change module name in Kconfig help and file header 
 
Version 4:
 - Use {readl,writel}_relaxed() calls
 - Add Guenter's Reviewed-by
 - Rebased onto v4.0-rc1
 
Version 3:
 - Move Regmap pointer into core device data structure
 - Remove error message from devm_ioremap_resource
 
Version 2:
 - Only calculate keepalive once in probe()
 - Check for a 0 clk_rate
 - Set limits using predefined attributes from watchdog_device
 - CONFIG_PM => CONFIG_SLEEP
 - Call st_wdog_setup() on resume
 - Remove MFD driver -- instead rely on driver probing mechanism
   which continues attempting to bind to different drivers until
   one does not return -ENODEV

Lee Jones (9):
  mfd: dt-bindings: Provide human readable defines for LPC mode choosing
  ARM: multi_v7_defconfig: Enable support for ST's LPC Watchdog
  ARM: multi_v7_defconfig: Enable support for ST's LPC RTC
  ARM: STi: DT: STiH407: Add Device Tree node for the LPC
  watchdog: bindings: Provide ST bindings for ST's LPC Watchdog device
  watchdog: st_wdt: Add new driver for ST's LPC Watchdog
  rtc: bindings: Provide ST bindings for ST's LPC RTC device
  rtc: st: add new driver for ST's LPC RTC
  MAINTAINERS: Add Watchdog and RTC files to STI's maintainer entry

 .../devicetree/bindings/rtc/rtc-st-lpc.txt         |  25 ++
 .../devicetree/bindings/watchdog/st_lpc_wdt.txt    |  38 +++
 MAINTAINERS                                        |   2 +
 arch/arm/boot/dts/stih407-family.dtsi              |  20 ++
 arch/arm/configs/multi_v7_defconfig                |   2 +
 drivers/rtc/Kconfig                                |  12 +
 drivers/rtc/Makefile                               |   1 +
 drivers/rtc/rtc-st-lpc.c                           | 354 +++++++++++++++++++++
 drivers/watchdog/Kconfig                           |  13 +
 drivers/watchdog/Makefile                          |   1 +
 drivers/watchdog/st_lpc_wdt.c                      | 344 ++++++++++++++++++++
 include/dt-bindings/mfd/st-lpc.h                   |  15 +
 12 files changed, 827 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/rtc-st-lpc.txt
 create mode 100644 Documentation/devicetree/bindings/watchdog/st_lpc_wdt.txt
 create mode 100644 drivers/rtc/rtc-st-lpc.c
 create mode 100644 drivers/watchdog/st_lpc_wdt.c
 create mode 100644 include/dt-bindings/mfd/st-lpc.h

-- 
1.9.1

[PATCH v5 1/9] mfd: dt-bindings: Provide human readable defines for LPC mode choosing

[Lee Jones]

ST's Low Power Controller can currently operate in two supported modes;
Watchdog and Real Time Clock.  These defines will aid engineers to easily
identify the selected mode.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 include/dt-bindings/mfd/st-lpc.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 include/dt-bindings/mfd/st-lpc.h

diff --git a/include/dt-bindings/mfd/st-lpc.h b/include/dt-bindings/mfd/st-lpc.h
new file mode 100644
index 0000000..e3e6c75
--- /dev/null
+++ b/include/dt-bindings/mfd/st-lpc.h
@@ -0,0 +1,15 @@
+/*
+ * This header provides shared DT/Driver defines for ST's LPC device
+ *
+ * Copyright (C) 2014 STMicroelectronics -- All Rights Reserved
+ *
+ * Author: Lee Jones <lee.jones@linaro.org> for STMicroelectronics
+ */
+
+#ifndef __DT_BINDINGS_ST_LPC_H__
+#define __DT_BINDINGS_ST_LPC_H__
+
+#define ST_LPC_MODE_RTC		0
+#define ST_LPC_MODE_WDT		1
+
+#endif /* __DT_BINDINGS_ST_LPC_H__ */
-- 
1.9.1

Re: [v5, 1/9] mfd: dt-bindings: Provide human readable defines for LPC mode choosing

[Guenter Roeck]

On Wed, Mar 04, 2015 at 06:06:30PM +0000, Lee Jones wrote:
> ST's Low Power Controller can currently operate in two supported modes;
> Watchdog and Real Time Clock.  These defines will aid engineers to easily
> identify the selected mode.
> 
> Signed-off-by: Lee Jones <lee.jones@linaro.org>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

[PATCH v5 2/9] ARM: multi_v7_defconfig: Enable support for ST's LPC Watchdog

[Lee Jones]

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/arm/configs/multi_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index e8a4c95..0f172f8 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -288,6 +288,7 @@ CONFIG_WATCHDOG=y
 CONFIG_XILINX_WATCHDOG=y
 CONFIG_ARM_SP805_WATCHDOG=y
 CONFIG_ORION_WATCHDOG=y
+CONFIG_ST_LPC_WATCHDOG=y
 CONFIG_SUNXI_WATCHDOG=y
 CONFIG_MESON_WATCHDOG=y
 CONFIG_MFD_AS3722=y
-- 
1.9.1

[PATCH v5 3/9] ARM: multi_v7_defconfig: Enable support for ST's LPC RTC

[Lee Jones]

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/arm/configs/multi_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index 0f172f8..1a861c9 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -423,6 +423,7 @@ CONFIG_RTC_DRV_DS1307=y
 CONFIG_RTC_DRV_MAX8907=y
 CONFIG_RTC_DRV_MAX77686=y
 CONFIG_RTC_DRV_PALMAS=y
+CONFIG_RTC_DRV_ST_LPC=y
 CONFIG_RTC_DRV_TWL4030=y
 CONFIG_RTC_DRV_TPS6586X=y
 CONFIG_RTC_DRV_TPS65910=y
-- 
1.9.1

[PATCH v5 4/9] ARM: STi: DT: STiH407: Add Device Tree node for the LPC

[Lee Jones]

On current ST platforms the LPC controls a number of functions.  This
patch enables support for the LPC Watchdog and LPC RTC devices on LPC1
and LPC2 respectively.

Signed-off-by: David Paris <david.paris@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/arm/boot/dts/stih407-family.dtsi | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/arm/boot/dts/stih407-family.dtsi b/arch/arm/boot/dts/stih407-family.dtsi
index c06a546..2b2315d 100644
--- a/arch/arm/boot/dts/stih407-family.dtsi
+++ b/arch/arm/boot/dts/stih407-family.dtsi
@@ -7,6 +7,7 @@
  * publishhed by the Free Software Foundation.
  */
 #include "stih407-pinctrl.dtsi"
+#include <dt-bindings/mfd/st-lpc.h>
 #include <dt-bindings/reset-controller/stih407-resets.h>
 / {
 	#address-cells = <1>;
@@ -336,5 +337,24 @@
 				resets = <&softreset STIH407_MIPHY2_SOFTRESET>;
 			};
 		};
+
+		/* Watchdog and Real-Time Clock */
+		lpc@8787000 {
+			compatible = "st,stih407-lpc";
+			reg = <0x8787000 0x1000>;
+			interrupts = <GIC_SPI 129 IRQ_TYPE_EDGE_RISING>;
+			clocks = <&clk_s_d3_flexgen CLK_LPC_0>;
+			timeout-sec = <120>;
+			st,syscfg = <&syscfg_core>;
+			st,lpc-mode = <ST_LPC_MODE_WDT>;
+		};
+
+		lpc@8788000 {
+			compatible = "st,stih407-lpc";
+			reg = <0x8788000 0x1000>;
+			interrupts = <GIC_SPI 130 IRQ_TYPE_EDGE_RISING>;
+			clocks = <&clk_s_d3_flexgen CLK_LPC_1>;
+			st,lpc-mode = <ST_LPC_MODE_RTC>;
+		};
 	};
 };
-- 
1.9.1

[PATCH v5 5/9] watchdog: bindings: Provide ST bindings for ST's LPC Watchdog device

[Lee Jones]

On current ST platforms the LPC controls a number of functions including
Watchdog and Real Time Clock.  This patch provides the bindings used to
configure LPC in Watchdog mode.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 .../devicetree/bindings/watchdog/st_lpc_wdt.txt    | 38 ++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/st_lpc_wdt.txt

diff --git a/Documentation/devicetree/bindings/watchdog/st_lpc_wdt.txt b/Documentation/devicetree/bindings/watchdog/st_lpc_wdt.txt
new file mode 100644
index 0000000..1bdf023
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/st_lpc_wdt.txt
@@ -0,0 +1,38 @@
+STMicroelectronics Low Power Controller (LPC) - Watchdog
+========================================================
+
+LPC currently supports Watchdog OR Real Time Clock functionality.
+
+[See: ../rtc/rtc-st-lpc.txt for RTC options]
+
+Required properties
+
+- compatible 	: Must be one of: "st,stih407-lpc" "st,stih416-lpc"
+				  "st,stih415-lpc" "st,stid127-lpc"
+- reg		: LPC registers base address + size
+- interrupts    : LPC interrupt line number and associated flags
+- clocks	: Clock used by LPC device (See: ../clock/clock-bindings.txt)
+- st,lpc-mode	: The LPC can run either one of two modes ST_LPC_MODE_RTC [0] or
+		  ST_LPC_MODE_WDT [1].  One (and only one) mode must be
+		  selected.
+
+Required properties [watchdog mode]
+
+- st,syscfg	: Phandle to syscfg node used to enable watchdog and configure
+		  CPU reset type.
+- timeout-sec	: Watchdog timeout in seconds
+
+Optional properties [watchdog mode]
+
+- st,warm-reset	: If present reset type will be 'warm' - if not it will be cold
+
+Example:
+	lpc@fde05000 {
+		compatible	= "st,stih416-lpc-watchdog";
+		reg		= <0xfde05000 0x1000>;
+		clocks 		= <&clk_s_d3_flexgen CLK_LPC_0>;
+		st,syscfg	= <&syscfg_core>;
+		timeout-sec	= <120>;
+		st,lpc-mode	= <ST_LPC_MODE_WDT>;
+		st,warm-reset;
+	};
-- 
1.9.1

[PATCH v5 6/9] watchdog: st_wdt: Add new driver for ST's LPC Watchdog

[Lee Jones]

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David Paris <david.paris@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/watchdog/Kconfig      |  13 ++
 drivers/watchdog/Makefile     |   1 +
 drivers/watchdog/st_lpc_wdt.c | 344 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 358 insertions(+)
 create mode 100644 drivers/watchdog/st_lpc_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 16f2023..8ccd9d9 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -471,6 +471,19 @@ config SIRFSOC_WATCHDOG
 	  Support for CSR SiRFprimaII and SiRFatlasVI watchdog. When
 	  the watchdog triggers the system will be reset.
 
+config ST_LPC_WATCHDOG
+	tristate "STMicroelectronics LPC Watchdog"
+	depends on ARCH_STI
+	depends on OF
+	select WATCHDOG_CORE
+	select MFD_ST_LPC
+	help
+	  Say Y here to include STMicroelectronics Low Power Controller
+	  (LPC) based Watchdog timer support.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called st_lpc_wdt.
+
 config TEGRA_WATCHDOG
 	tristate "Tegra watchdog"
 	depends on (ARCH_TEGRA || COMPILE_TEST) && HAS_IOMEM
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 5c19294..d98768c 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -59,6 +59,7 @@ obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
 obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
 obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o
 obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o
+obj-$(CONFIG_ST_LPC_WATCHDOG) += st_lpc_wdt.o
 obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o
 obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o
 obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o
diff --git a/drivers/watchdog/st_lpc_wdt.c b/drivers/watchdog/st_lpc_wdt.c
new file mode 100644
index 0000000..f32be15
--- /dev/null
+++ b/drivers/watchdog/st_lpc_wdt.c
@@ -0,0 +1,344 @@
+/*
+ * ST's LPC Watchdog
+ *
+ * Copyright (C) 2014 STMicroelectronics -- All Rights Reserved
+ *
+ * Author: David Paris <david.paris@st.com> for STMicroelectronics
+ *         Lee Jones <lee.jones@linaro.org> for STMicroelectronics
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/watchdog.h>
+
+#include <dt-bindings/mfd/st-lpc.h>
+
+/* Low Power Alarm */
+#define LPC_LPA_LSB_OFF			0x410
+#define LPC_LPA_START_OFF		0x418
+
+/* LPC as WDT */
+#define LPC_WDT_OFF			0x510
+
+static struct watchdog_device st_wdog_dev;
+
+struct st_wdog_syscfg {
+	unsigned int reset_type_reg;
+	unsigned int reset_type_mask;
+	unsigned int enable_reg;
+	unsigned int enable_mask;
+};
+
+struct st_wdog {
+	void __iomem *base;
+	struct device *dev;
+	struct regmap *regmap;
+	struct st_wdog_syscfg *syscfg;
+	struct clk *clk;
+	unsigned long clkrate;
+	bool warm_reset;
+};
+
+static struct st_wdog_syscfg stid127_syscfg = {
+	.reset_type_reg		= 0x004,
+	.reset_type_mask	= BIT(2),
+	.enable_reg		= 0x000,
+	.enable_mask		= BIT(2),
+};
+
+static struct st_wdog_syscfg stih415_syscfg = {
+	.reset_type_reg		= 0x0B8,
+	.reset_type_mask	= BIT(6),
+	.enable_reg		= 0x0B4,
+	.enable_mask		= BIT(7),
+};
+
+static struct st_wdog_syscfg stih416_syscfg = {
+	.reset_type_reg		= 0x88C,
+	.reset_type_mask	= BIT(6),
+	.enable_reg		= 0x888,
+	.enable_mask		= BIT(7),
+};
+
+static struct st_wdog_syscfg stih407_syscfg = {
+	.enable_reg		= 0x204,
+	.enable_mask		= BIT(19),
+};
+
+static const struct of_device_id st_wdog_match[] = {
+	{
+		.compatible = "st,stih407-lpc",
+		.data = &stih407_syscfg,
+	},
+	{
+		.compatible = "st,stih416-lpc",
+		.data = &stih416_syscfg,
+	},
+	{
+		.compatible = "st,stih415-lpc",
+		.data = &stih415_syscfg,
+	},
+	{
+		.compatible = "st,stid127-lpc",
+		.data = &stid127_syscfg,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, st_wdog_match);
+
+static void st_wdog_setup(struct st_wdog *st_wdog, bool enable)
+{
+	/* Type of watchdog reset - 0: Cold 1: Warm */
+	if (st_wdog->syscfg->reset_type_reg)
+		regmap_update_bits(st_wdog->regmap,
+				   st_wdog->syscfg->reset_type_reg,
+				   st_wdog->syscfg->reset_type_mask,
+				   st_wdog->warm_reset);
+
+	/* Mask/unmask watchdog reset */
+	regmap_update_bits(st_wdog->regmap,
+			   st_wdog->syscfg->enable_reg,
+			   st_wdog->syscfg->enable_mask,
+			   enable ? 0 : st_wdog->syscfg->enable_mask);
+}
+
+static void st_wdog_load_timer(struct st_wdog *st_wdog, unsigned int timeout)
+{
+	unsigned long clkrate = st_wdog->clkrate;
+
+	writel_relaxed(timeout * clkrate, st_wdog->base + LPC_LPA_LSB_OFF);
+	writel_relaxed(1, st_wdog->base + LPC_LPA_START_OFF);
+}
+
+static int st_wdog_start(struct watchdog_device *wdd)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
+
+	writel_relaxed(1, st_wdog->base + LPC_WDT_OFF);
+
+	return 0;
+}
+
+static int st_wdog_stop(struct watchdog_device *wdd)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
+
+	writel_relaxed(0, st_wdog->base + LPC_WDT_OFF);
+
+	return 0;
+}
+
+static int st_wdog_set_timeout(struct watchdog_device *wdd,
+			       unsigned int timeout)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
+
+	wdd->timeout = timeout;
+	st_wdog_load_timer(st_wdog, timeout);
+
+	return 0;
+}
+
+static int st_wdog_keepalive(struct watchdog_device *wdd)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
+
+	st_wdog_load_timer(st_wdog, wdd->timeout);
+
+	return 0;
+}
+
+static const struct watchdog_info st_wdog_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.identity = "ST LPC WDT",
+};
+
+static const struct watchdog_ops st_wdog_ops = {
+	.owner		= THIS_MODULE,
+	.start		= st_wdog_start,
+	.stop		= st_wdog_stop,
+	.ping		= st_wdog_keepalive,
+	.set_timeout	= st_wdog_set_timeout,
+};
+
+static struct watchdog_device st_wdog_dev = {
+	.info		= &st_wdog_info,
+	.ops		= &st_wdog_ops,
+};
+
+static int st_wdog_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct device_node *np = pdev->dev.of_node;
+	struct st_wdog *st_wdog;
+	struct regmap *regmap;
+	struct resource *res;
+	struct clk *clk;
+	void __iomem *base;
+	uint32_t mode;
+	int ret;
+
+	ret = of_property_read_u32(np, "st,lpc-mode", &mode);
+	if (ret) {
+		dev_err(&pdev->dev, "An LPC mode must be provided\n");
+		return -EINVAL;
+	}
+
+	/* LPC can either run in RTC or WDT mode */
+	if (mode != ST_LPC_MODE_WDT)
+		return -ENODEV;
+
+	st_wdog = devm_kzalloc(&pdev->dev, sizeof(*st_wdog), GFP_KERNEL);
+	if (!st_wdog)
+		return -ENOMEM;
+
+	match = of_match_device(st_wdog_match, &pdev->dev);
+	if (!match) {
+		dev_err(&pdev->dev, "Couldn't match device\n");
+		return -ENODEV;
+	}
+	st_wdog->syscfg	= (struct st_wdog_syscfg *)match->data;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
+	if (IS_ERR(regmap)) {
+		dev_err(&pdev->dev, "No syscfg phandle specified\n");
+		return PTR_ERR(regmap);
+	}
+
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "Unable to request clock\n");
+		return PTR_ERR(clk);
+	}
+
+	st_wdog->dev		= &pdev->dev;
+	st_wdog->base		= base;
+	st_wdog->clk		= clk;
+	st_wdog->regmap		= regmap;
+	st_wdog->warm_reset	= of_property_read_bool(np, "st,warm_reset");
+	st_wdog->clkrate	= clk_get_rate(st_wdog->clk);
+
+	if (!st_wdog->clkrate) {
+		dev_err(&pdev->dev, "Unable to fetch clock rate\n");
+		return -EINVAL;
+	}
+	st_wdog_dev.max_timeout = 0xFFFFFFFF / st_wdog->clkrate;
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to enable clock\n");
+		return ret;
+	}
+
+	watchdog_set_drvdata(&st_wdog_dev, st_wdog);
+	watchdog_set_nowayout(&st_wdog_dev, WATCHDOG_NOWAYOUT);
+
+	/* Init Watchdog timeout with value in DT */
+	ret = watchdog_init_timeout(&st_wdog_dev, 0, &pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to initialise watchdog timeout\n");
+		clk_disable_unprepare(clk);
+		return ret;
+	}
+
+	ret = watchdog_register_device(&st_wdog_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to register watchdog\n");
+		clk_disable_unprepare(clk);
+		return ret;
+	}
+
+	st_wdog_setup(st_wdog, true);
+
+	dev_info(&pdev->dev, "LPC Watchdog driver registered, reset type is %s",
+		 st_wdog->warm_reset ? "warm" : "cold");
+
+	return ret;
+}
+
+static int st_wdog_remove(struct platform_device *pdev)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev);
+
+	st_wdog_setup(st_wdog, false);
+	watchdog_unregister_device(&st_wdog_dev);
+	clk_disable_unprepare(st_wdog->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int st_wdog_suspend(struct device *dev)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev);
+
+	if (watchdog_active(&st_wdog_dev))
+		st_wdog_stop(&st_wdog_dev);
+
+	st_wdog_setup(st_wdog, false);
+
+	clk_disable(st_wdog->clk);
+
+	return 0;
+}
+
+static int st_wdog_resume(struct device *dev)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev);
+	int ret;
+
+	ret = clk_enable(st_wdog->clk);
+	if (ret) {
+		dev_err(dev, "Unable to re-enable clock\n");
+		watchdog_unregister_device(&st_wdog_dev);
+		clk_unprepare(st_wdog->clk);
+		return ret;
+	}
+
+	st_wdog_setup(st_wdog, true);
+
+	if (watchdog_active(&st_wdog_dev)) {
+		st_wdog_load_timer(st_wdog, st_wdog_dev.timeout);
+		st_wdog_start(&st_wdog_dev);
+	}
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(st_wdog_pm_ops,
+			 st_wdog_suspend,
+			 st_wdog_resume);
+
+static struct platform_driver st_wdog_driver = {
+	.driver	= {
+		.name = "st-lpc-wdt",
+		.pm = &st_wdog_pm_ops,
+		.of_match_table = st_wdog_match,
+	},
+	.probe = st_wdog_probe,
+	.remove = st_wdog_remove,
+};
+module_platform_driver(st_wdog_driver);
+
+MODULE_AUTHOR("David Paris <david.paris@st.com>");
+MODULE_DESCRIPTION("ST LPC Watchdog Driver");
+MODULE_LICENSE("GPL");
-- 
1.9.1

[PATCH v5 7/9] rtc: bindings: Provide ST bindings for ST's LPC RTC device

[Lee Jones]

On current ST platforms the LPC controls a number of functions including
Watchdog and Real Time Clock.  This patch provides the bindings used to
configure LPC in RTC mode.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 .../devicetree/bindings/rtc/rtc-st-lpc.txt         | 25 ++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/rtc-st-lpc.txt

diff --git a/Documentation/devicetree/bindings/rtc/rtc-st-lpc.txt b/Documentation/devicetree/bindings/rtc/rtc-st-lpc.txt
new file mode 100644
index 0000000..aaf9855
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/rtc-st-lpc.txt
@@ -0,0 +1,25 @@
+STMicroelectronics Low Power Controller (LPC) - RTC
+===================================================
+
+LPC currently supports Watchdog OR Real Time Clock functionality.
+
+[See: ../watchdog/st_lpc_wdt.txt for Watchdog options]
+
+Required properties
+
+- compatible 	: Must be one of: "st,stih407-lpc" "st,stih416-lpc"
+				  "st,stih415-lpc" "st,stid127-lpc"
+- reg		: LPC registers base address + size
+- interrupts    : LPC interrupt line number and associated flags
+- clocks	: Clock used by LPC device (See: ../clock/clock-bindings.txt)
+- st,lpc-mode	: The LPC can run either one of two modes ST_LPC_MODE_RTC [0] or
+		  ST_LPC_MODE_WDT [1].  One (and only one) mode must be
+		  selected.
+
+Example:
+	lpc@fde05000 {
+		compatible	= "st,stih416-lpc-watchdog";
+		reg		= <0xfde05000 0x1000>;
+		clocks 		= <&clk_s_d3_flexgen CLK_LPC_0>;
+		st,lpc-mode	= <ST_LPC_MODE_RTC>;
+	};
-- 
1.9.1

[PATCH v5 8/9] rtc: st: add new driver for ST's LPC RTC

[Lee Jones]

ST's Low Power Controller (LPC) controls two devices; watchdog and RTC.
Only one of the devices can be used at any one time.  This is enforced
by the correlating MFD driver.  This portion of the driver-set controls
the Real Time Clock.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/rtc/Kconfig      |  12 ++
 drivers/rtc/Makefile     |   1 +
 drivers/rtc/rtc-st-lpc.c | 354 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 367 insertions(+)
 create mode 100644 drivers/rtc/rtc-st-lpc.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index b5b5c3d..08a1020 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1500,6 +1500,18 @@ config RTC_DRV_SIRFSOC
 	  Say "yes" here to support the real time clock on SiRF SOC chips.
 	  This driver can also be built as a module called rtc-sirfsoc.
 
+config RTC_DRV_ST_LPC
+	tristate "STMicroelectronics LPC RTC"
+	depends on ARCH_STI
+	depends on OF
+	select MFD_ST_LPC
+	help
+	  Say Y here to include STMicroelectronics Low Power Controller
+	  (LPC) based RTC support.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called rtc-st-lpc.
+
 config RTC_DRV_MOXART
 	tristate "MOXA ART RTC"
 	depends on ARCH_MOXART || COMPILE_TEST
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 69c8706..dda6e33 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -152,4 +152,5 @@ obj-$(CONFIG_RTC_DRV_WM8350)	+= rtc-wm8350.o
 obj-$(CONFIG_RTC_DRV_X1205)	+= rtc-x1205.o
 obj-$(CONFIG_RTC_DRV_XGENE)	+= rtc-xgene.o
 obj-$(CONFIG_RTC_DRV_SIRFSOC)	+= rtc-sirfsoc.o
+obj-$(CONFIG_RTC_DRV_ST_LPC)	+= rtc-st-lpc.o
 obj-$(CONFIG_RTC_DRV_MOXART)	+= rtc-moxart.o
diff --git a/drivers/rtc/rtc-st-lpc.c b/drivers/rtc/rtc-st-lpc.c
new file mode 100644
index 0000000..ab8cee9
--- /dev/null
+++ b/drivers/rtc/rtc-st-lpc.c
@@ -0,0 +1,354 @@
+/*
+ * rtc-st-lpc.c - ST's LPC RTC, powered by the Low Power Timer
+ *
+ * Copyright (C) 2014 STMicroelectronics Limited
+ *
+ * Author: David Paris <david.paris@st.com> for STMicroelectronics
+ *         Lee Jones <lee.jones@linaro.org> for STMicroelectronics
+ *
+ * Based on the original driver written by Stuart Menefy.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+#include <dt-bindings/mfd/st-lpc.h>
+
+/* Low Power Timer */
+#define LPC_LPT_LSB_OFF		0x400
+#define LPC_LPT_MSB_OFF		0x404
+#define LPC_LPT_START_OFF	0x408
+
+/* Low Power Alarm */
+#define LPC_LPA_LSB_OFF		0x410
+#define LPC_LPA_MSB_OFF		0x414
+#define LPC_LPA_START_OFF	0x418
+
+/* LPC as WDT */
+#define LPC_WDT_OFF		0x510
+#define LPC_WDT_FLAG_OFF	0x514
+
+struct st_rtc {
+	struct rtc_device *rtc_dev;
+	struct rtc_wkalrm alarm;
+	struct resource *res;
+	struct clk *clk;
+	unsigned long clkrate;
+	void __iomem *ioaddr;
+	bool irq_enabled:1;
+	spinlock_t lock;
+	short irq;
+};
+
+static void st_rtc_set_hw_alarm(struct st_rtc *rtc,
+				unsigned long msb, unsigned long  lsb)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&rtc->lock, flags);
+
+	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);
+
+	writel_relaxed(msb, rtc->ioaddr + LPC_LPA_MSB_OFF);
+	writel_relaxed(lsb, rtc->ioaddr + LPC_LPA_LSB_OFF);
+	writel_relaxed(1, rtc->ioaddr + LPC_LPA_START_OFF);
+
+	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);
+
+	spin_unlock_irqrestore(&rtc->lock, flags);
+}
+
+static irqreturn_t st_rtc_handler(int this_irq, void *data)
+{
+	struct st_rtc *rtc = (struct st_rtc *)data;
+
+	rtc_update_irq(rtc->rtc_dev, 1, RTC_AF);
+
+	return IRQ_HANDLED;
+}
+
+static int st_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct st_rtc *rtc = dev_get_drvdata(dev);
+	unsigned long lpt_lsb, lpt_msb;
+	unsigned long long lpt;
+	unsigned long flags;
+
+	spin_lock_irqsave(&rtc->lock, flags);
+
+	do {
+		lpt_msb = readl_relaxed(rtc->ioaddr + LPC_LPT_MSB_OFF);
+		lpt_lsb = readl_relaxed(rtc->ioaddr + LPC_LPT_LSB_OFF);
+	} while (readl_relaxed(rtc->ioaddr + LPC_LPT_MSB_OFF) != lpt_msb);
+
+	spin_unlock_irqrestore(&rtc->lock, flags);
+
+	lpt = ((unsigned long long)lpt_msb << 32) | lpt_lsb;
+	do_div(lpt, rtc->clkrate);
+	rtc_time_to_tm(lpt, tm);
+
+	return 0;
+}
+
+static int st_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct st_rtc *rtc = dev_get_drvdata(dev);
+	unsigned long long lpt;
+	unsigned long secs, flags;
+	int ret;
+
+	ret = rtc_tm_to_time(tm, &secs);
+	if (ret)
+		return ret;
+
+	lpt = (unsigned long long)secs * rtc->clkrate;
+
+	spin_lock_irqsave(&rtc->lock, flags);
+
+	writel_relaxed(lpt >> 32, rtc->ioaddr + LPC_LPT_MSB_OFF);
+	writel_relaxed(lpt, rtc->ioaddr + LPC_LPT_LSB_OFF);
+	writel_relaxed(1, rtc->ioaddr + LPC_LPT_START_OFF);
+
+	spin_unlock_irqrestore(&rtc->lock, flags);
+
+	return 0;
+}
+
+static int st_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
+{
+	struct st_rtc *rtc = dev_get_drvdata(dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&rtc->lock, flags);
+
+	memcpy(wkalrm, &rtc->alarm, sizeof(struct rtc_wkalrm));
+
+	spin_unlock_irqrestore(&rtc->lock, flags);
+
+	return 0;
+}
+
+static int st_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct st_rtc *rtc = dev_get_drvdata(dev);
+
+	if (enabled && !rtc->irq_enabled) {
+		enable_irq(rtc->irq);
+		rtc->irq_enabled = true;
+	} else if (!enabled && rtc->irq_enabled) {
+		disable_irq(rtc->irq);
+		rtc->irq_enabled = false;
+	}
+
+	return 0;
+}
+
+static int st_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+	struct st_rtc *rtc = dev_get_drvdata(dev);
+	struct rtc_time now;
+	unsigned long now_secs;
+	unsigned long alarm_secs;
+	unsigned long long lpa;
+
+	st_rtc_read_time(dev, &now);
+	rtc_tm_to_time(&now, &now_secs);
+	rtc_tm_to_time(&t->time, &alarm_secs);
+
+	/* Invalid alarm time */
+	if (now_secs > alarm_secs)
+		return -EINVAL;
+
+	memcpy(&rtc->alarm, t, sizeof(struct rtc_wkalrm));
+
+	/* Now many secs to fire */
+	alarm_secs -= now_secs;
+	lpa = (unsigned long long)alarm_secs * rtc->clkrate;
+
+	st_rtc_set_hw_alarm(rtc, lpa >> 32, lpa);
+	st_rtc_alarm_irq_enable(dev, t->enabled);
+
+	return 0;
+}
+
+static struct rtc_class_ops st_rtc_ops = {
+	.read_time		= st_rtc_read_time,
+	.set_time		= st_rtc_set_time,
+	.read_alarm		= st_rtc_read_alarm,
+	.set_alarm		= st_rtc_set_alarm,
+	.alarm_irq_enable	= st_rtc_alarm_irq_enable,
+};
+
+static int st_rtc_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct st_rtc *rtc;
+	struct resource *res;
+	struct rtc_time tm_check;
+	uint32_t mode;
+	int ret = 0;
+
+	ret = of_property_read_u32(np, "st,lpc-mode", &mode);
+	if (ret) {
+		dev_err(&pdev->dev, "An LPC mode must be provided\n");
+		return -EINVAL;
+	}
+
+	/* LPC can either run in RTC or WDT mode */
+	if (mode != ST_LPC_MODE_RTC)
+		return -ENODEV;
+
+	rtc = devm_kzalloc(&pdev->dev, sizeof(struct st_rtc), GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	spin_lock_init(&rtc->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	rtc->ioaddr = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(rtc->ioaddr))
+		return PTR_ERR(rtc->ioaddr);
+
+	rtc->irq = irq_of_parse_and_map(np, 0);
+	if (!rtc->irq) {
+		dev_err(&pdev->dev, "IRQ missing or invalid\n");
+		return -EINVAL;
+	}
+
+	ret = devm_request_irq(&pdev->dev, rtc->irq, st_rtc_handler, 0,
+			       pdev->name, rtc);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq %i\n", rtc->irq);
+		return ret;
+	}
+
+	enable_irq_wake(rtc->irq);
+	disable_irq(rtc->irq);
+
+	rtc->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(rtc->clk)) {
+		dev_err(&pdev->dev, "Unable to request clock\n");
+		return PTR_ERR(rtc->clk);
+	}
+
+	clk_prepare_enable(rtc->clk);
+
+	rtc->clkrate = clk_get_rate(rtc->clk);
+	if (!rtc->clkrate) {
+		dev_err(&pdev->dev, "Unable to fetch clock rate\n");
+		return -EINVAL;
+	}
+
+	device_set_wakeup_capable(&pdev->dev, 1);
+
+	platform_set_drvdata(pdev, rtc);
+
+	/*
+	 * The RTC-LPC is able to manage date.year > 2038
+	 * but currently the kernel can not manage this date!
+	 * If the RTC-LPC has a date.year > 2038 then
+	 * it's set to the epoch "Jan 1st 2000"
+	 */
+	st_rtc_read_time(&pdev->dev, &tm_check);
+
+	if (tm_check.tm_year >=  (2038 - 1900)) {
+		memset(&tm_check, 0, sizeof(tm_check));
+		tm_check.tm_year = 100;
+		tm_check.tm_mday = 1;
+		st_rtc_set_time(&pdev->dev, &tm_check);
+	}
+
+	rtc->rtc_dev = rtc_device_register("st-lpc-rtc", &pdev->dev,
+					   &st_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc->rtc_dev)) {
+		clk_disable_unprepare(rtc->clk);
+		return PTR_ERR(rtc->rtc_dev);
+	}
+
+	return 0;
+}
+
+static int st_rtc_remove(struct platform_device *pdev)
+{
+	struct st_rtc *rtc = platform_get_drvdata(pdev);
+
+	if (likely(rtc->rtc_dev))
+		rtc_device_unregister(rtc->rtc_dev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int st_rtc_suspend(struct device *dev)
+{
+	struct st_rtc *rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		return 0;
+
+	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);
+	writel_relaxed(0, rtc->ioaddr + LPC_LPA_START_OFF);
+	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);
+
+	return 0;
+}
+
+static int st_rtc_resume(struct device *dev)
+{
+	struct st_rtc *rtc = dev_get_drvdata(dev);
+
+	rtc_alarm_irq_enable(rtc->rtc_dev, 0);
+
+	/*
+	 * clean 'rtc->alarm' to allow a new
+	 * .set_alarm to the upper RTC layer
+	 */
+	memset(&rtc->alarm, 0, sizeof(struct rtc_wkalrm));
+
+	writel_relaxed(0, rtc->ioaddr + LPC_LPA_MSB_OFF);
+	writel_relaxed(0, rtc->ioaddr + LPC_LPA_LSB_OFF);
+	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);
+	writel_relaxed(1, rtc->ioaddr + LPC_LPA_START_OFF);
+	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(st_rtc_pm_ops, st_rtc_suspend, st_rtc_resume);
+
+static const struct of_device_id st_rtc_match[] = {
+	{ .compatible = "st,stih407-lpc" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, st_wdog_match);
+
+static struct platform_driver st_rtc_platform_driver = {
+	.driver = {
+		.name = "st-lpc-rtc",
+		.pm = &st_rtc_pm_ops,
+		.of_match_table = st_rtc_match,
+	},
+	.probe = st_rtc_probe,
+	.remove = st_rtc_remove,
+};
+
+module_platform_driver(st_rtc_platform_driver);
+
+MODULE_DESCRIPTION("STMicroelectronics LPC RTC driver");
+MODULE_AUTHOR("David Paris <david.paris@st.com>");
+MODULE_LICENSE("GPLv2");
-- 
1.9.1

Re: [PATCH v5 8/9] rtc: st: add new driver for ST's LPC RTC

[Paul Bolle]

Lee Jones schreef op wo 04-03-2015 om 18:06 [+0000]:
> --- /dev/null
> +++ b/drivers/rtc/rtc-st-lpc.c
> @@ -0,0 +1,354 @@
> +/*
> + * rtc-st-lpc.c - ST's LPC RTC, powered by the Low Power Timer
> + *
> + * Copyright (C) 2014 STMicroelectronics Limited
> + *
> + * Author: David Paris <david.paris@st.com> for STMicroelectronics
> + *         Lee Jones <lee.jones@linaro.org> for STMicroelectronics
> + *
> + * Based on the original driver written by Stuart Menefy.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public Licence
> + * as published by the Free Software Foundation; either version
> + * 2 of the Licence, or (at your option) any later version.
> + */

This states the license is GPL v2 or later.

> +MODULE_LICENSE("GPLv2");

This will taint the kernel at module load, won't it? You probably meant
"GPL v2", but only
    MODULE_LICENSE("GPL");

correctly matches the license in the comment at the top of this file. 

(I assume I missed all this when looking at the v4 series.)


Paul Bolle

Re: [PATCH v5 8/9] rtc: st: add new driver for ST's LPC RTC

[Lee Jones]

On Wed, 04 Mar 2015, Paul Bolle wrote:

> Lee Jones schreef op wo 04-03-2015 om 18:06 [+0000]:
> > --- /dev/null
> > +++ b/drivers/rtc/rtc-st-lpc.c
> > @@ -0,0 +1,354 @@
> > +/*
> > + * rtc-st-lpc.c - ST's LPC RTC, powered by the Low Power Timer
> > + *
> > + * Copyright (C) 2014 STMicroelectronics Limited
> > + *
> > + * Author: David Paris <david.paris@st.com> for STMicroelectronics
> > + *         Lee Jones <lee.jones@linaro.org> for STMicroelectronics
> > + *
> > + * Based on the original driver written by Stuart Menefy.
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public Licence
> > + * as published by the Free Software Foundation; either version
> > + * 2 of the Licence, or (at your option) any later version.
> > + */
> 
> This states the license is GPL v2 or later.
> 
> > +MODULE_LICENSE("GPLv2");
> 
> This will taint the kernel at module load, won't it? You probably meant
> "GPL v2", but only
>     MODULE_LICENSE("GPL");
> 
> correctly matches the license in the comment at the top of this file. 
> 
> (I assume I missed all this when looking at the v4 series.)

Actually, I've already fixed this along with another typo I found
after resubmitting.  Always the way sadly.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

[PATCH v5 9/9] MAINTAINERS: Add Watchdog and RTC files to STI's maintainer entry

[Lee Jones]

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 MAINTAINERS | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index ddc5a8c..19af007 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1461,10 +1461,12 @@ F:	drivers/phy/phy-stih407-usb.c
 F:	drivers/phy/phy-stih41x-usb.c
 F:	drivers/pinctrl/pinctrl-st.c
 F:	drivers/reset/sti/
+F:	drivers/rtc/rtc-st-lpc.c
 F:	drivers/tty/serial/st-asc.c
 F:	drivers/usb/dwc3/dwc3-st.c
 F:	drivers/usb/host/ehci-st.c
 F:	drivers/usb/host/ohci-st.c
+F:	drivers/watchdog/st_lpc_wdt.c
 F:	drivers/ata/ahci_st.c
 
 ARM/TECHNOLOGIC SYSTEMS TS7250 MACHINE SUPPORT
-- 
1.9.1