[PATCH v3 0/9] Atmel System Timer cleanups

[PATCH v3 0/9] Atmel System Timer cleanups

[Alexandre Belloni]

This patch set cleans up the system timer driver.

The main goal is to get rid of the mach/ headers dependency. At the same time,
it introduces proper probing and locking (using a regmap) for the watchdog
driver.

This is based on 4.0-rc1 and will have two merge conflicts with my cleanup #1 in
mach-at91/at91rm9200.c

Changes in v3:
 - stop using an mfd and get the syscon directly from the watchdog driver
 - introduce a proper reset driver to handle reset

Changes in v2:
 - cleaned up more includes in the watchdog driver
 - stop using if OF when selecting CLKSRC_OF
 - stop initializing .owner

Alexandre Belloni (9):
  ARM: at91/dt: declare atmel,at91rm9200-st as a syscon
  mfd: syscon: Add atmel system timer registers definition
  watchdog: at91rm9200: use the system timer syscon
  power: reset: Add AT91RM9200 reset driver
  ARM: at91: at91rm9200: remove deprecated arm_pm_restart
  ARM: at91: time: move the system timer driver to drivers/clocksource
  clocksource: atmel-st: properly initialize driver
  clocksource: atmel-st: use syscon/regmap
  ARM: at91: remove useless include

 .../devicetree/bindings/arm/atmel-at91.txt         |   2 +-
 arch/arm/boot/dts/at91rm9200.dtsi                  |   2 +-
 arch/arm/mach-at91/Makefile                        |   2 +-
 arch/arm/mach-at91/at91rm9200.c                    |  19 ----
 arch/arm/mach-at91/generic.h                       |   3 -
 arch/arm/mach-at91/include/mach/at91_st.h          |  61 ------------
 drivers/clocksource/Kconfig                        |   4 +
 drivers/clocksource/Makefile                       |   1 +
 .../clocksource/timer-atmel-st.c                   | 103 ++++++++-------------
 drivers/power/reset/Kconfig                        |   7 ++
 drivers/power/reset/Makefile                       |   1 +
 drivers/power/reset/at91rm9200-reset.c             |  70 ++++++++++++++
 drivers/watchdog/Kconfig                           |   2 +-
 drivers/watchdog/at91rm9200_wdt.c                  |  21 +++--
 include/linux/mfd/syscon/atmel-st.h                |  47 ++++++++++
 15 files changed, 189 insertions(+), 156 deletions(-)
 delete mode 100644 arch/arm/mach-at91/include/mach/at91_st.h
 rename arch/arm/mach-at91/at91rm9200_time.c => drivers/clocksource/timer-atmel-st.c (77%)
 create mode 100644 drivers/power/reset/at91rm9200-reset.c
 create mode 100644 include/linux/mfd/syscon/atmel-st.h

-- 
2.1.0

[PATCH v3 1/9] ARM: at91/dt: declare atmel,at91rm9200-st as a syscon

[Alexandre Belloni]

The system timer register range is also used for the watchdog. Declare it as a
syscon to be able to get a regmap early enough in the boot process

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 Documentation/devicetree/bindings/arm/atmel-at91.txt | 2 +-
 arch/arm/boot/dts/at91rm9200.dtsi                    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/arm/atmel-at91.txt b/Documentation/devicetree/bindings/arm/atmel-at91.txt
index ad319f84f560..0fbb3582ec9d 100644
--- a/Documentation/devicetree/bindings/arm/atmel-at91.txt
+++ b/Documentation/devicetree/bindings/arm/atmel-at91.txt
@@ -46,7 +46,7 @@ PIT Timer required properties:
   shared across all System Controller members.
 
 System Timer (ST) required properties:
-- compatible: Should be "atmel,at91rm9200-st"
+- compatible: Should be "atmel,at91rm9200-st", "syscon"
 - reg: Should contain registers location and length
 - interrupts: Should contain interrupt for the ST which is the IRQ line
   shared across all System Controller members.
diff --git a/arch/arm/boot/dts/at91rm9200.dtsi b/arch/arm/boot/dts/at91rm9200.dtsi
index 21c2b504f977..1b1c1ac2c4f6 100644
--- a/arch/arm/boot/dts/at91rm9200.dtsi
+++ b/arch/arm/boot/dts/at91rm9200.dtsi
@@ -356,7 +356,7 @@
 			};
 
 			st: timer@fffffd00 {
-				compatible = "atmel,at91rm9200-st";
+				compatible = "atmel,at91rm9200-st", "syscon";
 				reg = <0xfffffd00 0x100>;
 				interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
 			};
-- 
2.1.0

[PATCH v3 2/9] mfd: syscon: Add atmel system timer registers definition

[Alexandre Belloni]

AT91RM920 has a memory range reserved for timer and watchdog configuration.
Expose those registers so that drivers can make use of the system timer syscon
declared in at91 DTs.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 include/linux/mfd/syscon/atmel-st.h | 47 +++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 include/linux/mfd/syscon/atmel-st.h

diff --git a/include/linux/mfd/syscon/atmel-st.h b/include/linux/mfd/syscon/atmel-st.h
new file mode 100644
index 000000000000..8e29a1028807
--- /dev/null
+++ b/include/linux/mfd/syscon/atmel-st.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2005 Ivan Kokshaysky
+ * Copyright (C) SAN People
+ *
+ * System Timer (ST) - System peripherals registers.
+ * Based on AT91RM9200 datasheet revision E.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef _LINUX_MFD_SYSCON_ATMEL_ST_H
+#define _LINUX_MFD_SYSCON_ATMEL_ST_H
+
+#define	AT91_ST_CR	0x00	/* Control Register */
+#define		AT91_ST_WDRST	(1 << 0)	/* Watchdog Timer Restart */
+
+#define	AT91_ST_PIMR	0x04	/* Period Interval Mode Register */
+#define		AT91_ST_PIV	(0xffff <<  0)	/* Period Interval Value */
+
+#define	AT91_ST_WDMR	0x08	/* Watchdog Mode Register */
+#define		AT91_ST_WDV	(0xffff <<  0)	/* Watchdog Counter Value */
+#define		AT91_ST_RSTEN	(1 << 16)	/* Reset Enable */
+#define		AT91_ST_EXTEN	(1 << 17)	/* External Signal Assertion Enable */
+
+#define	AT91_ST_RTMR	0x0c	/* Real-time Mode Register */
+#define		AT91_ST_RTPRES	(0xffff <<  0)	/* Real-time Prescalar Value */
+
+#define	AT91_ST_SR	0x10	/* Status Register */
+#define		AT91_ST_PITS	(1 << 0)	/* Period Interval Timer Status */
+#define		AT91_ST_WDOVF	(1 << 1)	/* Watchdog Overflow */
+#define		AT91_ST_RTTINC	(1 << 2)	/* Real-time Timer Increment */
+#define		AT91_ST_ALMS	(1 << 3)	/* Alarm Status */
+
+#define	AT91_ST_IER	0x14	/* Interrupt Enable Register */
+#define	AT91_ST_IDR	0x18	/* Interrupt Disable Register */
+#define	AT91_ST_IMR	0x1c	/* Interrupt Mask Register */
+
+#define	AT91_ST_RTAR	0x20	/* Real-time Alarm Register */
+#define		AT91_ST_ALMV	(0xfffff << 0)	/* Alarm Value */
+
+#define	AT91_ST_CRTR	0x24	/* Current Real-time Register */
+#define		AT91_ST_CRTV	(0xfffff << 0)	/* Current Real-Time Value */
+
+#endif /* _LINUX_MFD_SYSCON_ATMEL_ST_H */
-- 
2.1.0

[PATCH v3 3/9] watchdog: at91rm9200: use the system timer syscon

[Alexandre Belloni]

Use a syscon regmap to access the systemr timer registers.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/watchdog/Kconfig          |  2 +-
 drivers/watchdog/at91rm9200_wdt.c | 21 +++++++++++++++------
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 16f202350997..ce4f3a7f95fd 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -154,7 +154,7 @@ config ARM_SP805_WATCHDOG
 
 config AT91RM9200_WATCHDOG
 	tristate "AT91RM9200 watchdog"
-	depends on SOC_AT91RM9200
+	depends on SOC_AT91RM9200 && MFD_SYSCON
 	help
 	  Watchdog timer embedded into AT91RM9200 chips. This will reboot your
 	  system when the timeout is reached.
diff --git a/drivers/watchdog/at91rm9200_wdt.c b/drivers/watchdog/at91rm9200_wdt.c
index d244112d5b6f..34dd5eec79d8 100644
--- a/drivers/watchdog/at91rm9200_wdt.c
+++ b/drivers/watchdog/at91rm9200_wdt.c
@@ -17,22 +17,25 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/atmel-st.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
 #include <linux/uaccess.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
-#include <mach/at91_st.h>
 
 #define WDT_DEFAULT_TIME	5	/* seconds */
 #define WDT_MAX_TIME		256	/* seconds */
 
 static int wdt_time = WDT_DEFAULT_TIME;
 static bool nowayout = WATCHDOG_NOWAYOUT;
+static struct regmap *regmap_st;
 
 module_param(wdt_time, int, 0);
 MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
@@ -55,7 +58,7 @@ static unsigned long at91wdt_busy;
  */
 static inline void at91_wdt_stop(void)
 {
-	at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN);
+	regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN);
 }
 
 /*
@@ -63,9 +66,9 @@ static inline void at91_wdt_stop(void)
  */
 static inline void at91_wdt_start(void)
 {
-	at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
+	regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
 				(((65536 * wdt_time) >> 8) & AT91_ST_WDV));
-	at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
+	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
 }
 
 /*
@@ -73,7 +76,7 @@ static inline void at91_wdt_start(void)
  */
 static inline void at91_wdt_reload(void)
 {
-	at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
+	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
 }
 
 /* ......................................................................... */
@@ -203,12 +206,17 @@ static struct miscdevice at91wdt_miscdev = {
 
 static int at91wdt_probe(struct platform_device *pdev)
 {
+	struct device_node *np = pdev->dev.of_node;
 	int res;
 
 	if (at91wdt_miscdev.parent)
 		return -EBUSY;
 	at91wdt_miscdev.parent = &pdev->dev;
 
+	regmap_st = syscon_node_to_regmap(np);
+	if (!regmap_st)
+		return -ENODEV;
+
 	res = misc_register(&at91wdt_miscdev);
 	if (res)
 		return res;
@@ -255,6 +263,7 @@ static int at91wdt_resume(struct platform_device *pdev)
 #endif
 
 static const struct of_device_id at91_wdt_dt_ids[] = {
+	{ .compatible = "atmel,at91rm9200-st" },
 	{ .compatible = "atmel,at91rm9200-wdt" },
 	{ /* sentinel */ }
 };
@@ -267,7 +276,7 @@ static struct platform_driver at91wdt_driver = {
 	.suspend	= at91wdt_suspend,
 	.resume		= at91wdt_resume,
 	.driver		= {
-		.name	= "at91_wdt",
+		.name	= "atmel_st_watchdog",
 		.of_match_table = at91_wdt_dt_ids,
 	},
 };
-- 
2.1.0

[PATCH v3 4/9] power: reset: Add AT91RM9200 reset driver

[Alexandre Belloni]

AT91RM9200 uses the watchdog from the system timer to reset.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/power/reset/Kconfig            |  7 ++++
 drivers/power/reset/Makefile           |  1 +
 drivers/power/reset/at91rm9200-reset.c | 70 ++++++++++++++++++++++++++++++++++
 3 files changed, 78 insertions(+)
 create mode 100644 drivers/power/reset/at91rm9200-reset.c

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 27f6646731b0..8d79e45ae754 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -30,6 +30,13 @@ config POWER_RESET_AT91_RESET
 	  This driver supports restart for Atmel AT91SAM9 and SAMA5
 	  SoCs
 
+config POWER_RESET_AT91RM9200_RESET
+	bool "Atmel AT91RM9200 reset driver"
+	depends on ARCH_AT91 && MFD_SYSCON
+	default SOC_AT91RM9200
+	help
+	  This driver supports restart for Atmel AT91RM9200.
+
 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 11de15bae52e..96e972bbb922 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_AT91RM9200_RESET) += at91rm9200-reset.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/at91rm9200-reset.c b/drivers/power/reset/at91rm9200-reset.c
new file mode 100644
index 000000000000..b4c542e39512
--- /dev/null
+++ b/drivers/power/reset/at91rm9200-reset.c
@@ -0,0 +1,70 @@
+/*
+ * Atmel AT91 SAM9 SoCs reset code
+ *
+ * Copyright (C) 2007 Atmel Corporation.
+ * Copyright (C) BitBox Ltd 2010
+ * Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcosoft.com>
+ * Copyright (C) 2014 Free Electrons
+ *
+ * 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/atmel-st.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+
+static struct regmap *regmap_st;
+
+static int at91rm9200_restart(struct notifier_block *this,
+					unsigned long mode, void *cmd)
+{
+	/*
+	 * Perform a hardware reset with the use of the Watchdog timer.
+	 */
+	regmap_write(regmap_st, AT91_ST_WDMR,
+		     AT91_ST_RSTEN | AT91_ST_EXTEN | 1);
+	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
+
+	mdelay(2000);
+
+	pr_emerg("Unable to restart system\n");
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block at91rm9200_restart_nb = {
+	.notifier_call = at91rm9200_restart,
+	.priority = 192,
+};
+
+static int at91rm9200_reset_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+
+	regmap_st = syscon_node_to_regmap(np);
+	if (!regmap_st)
+		return -ENODEV;
+
+	return register_restart_handler(&at91rm9200_restart_nb);
+}
+
+static const struct of_device_id at91rm9200_reset_of_match[] = {
+	{ .compatible = "atmel,at91rm9200-st" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver at91rm9200_reset_driver = {
+	.probe = at91rm9200_reset_probe,
+	.driver = {
+		.name = "at91rm9200-reset",
+		.of_match_table = at91rm9200_reset_of_match,
+	},
+};
+module_platform_driver(at91rm9200_reset_driver);
-- 
2.1.0

[PATCH v3 5/9] ARM: at91: at91rm9200: remove deprecated arm_pm_restart

[Alexandre Belloni]

Now that a proper driver is available, remove at91rm9200_restart.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 arch/arm/mach-at91/at91rm9200.c | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/arch/arm/mach-at91/at91rm9200.c b/arch/arm/mach-at91/at91rm9200.c
index 8fcfb70f7124..2386d08d65e8 100644
--- a/arch/arm/mach-at91/at91rm9200.c
+++ b/arch/arm/mach-at91/at91rm9200.c
@@ -24,19 +24,8 @@
 #include <asm/mach/irq.h>
 #include <asm/system_misc.h>
 
-#include <mach/at91_st.h>
-
 #include "generic.h"
 
-static void at91rm9200_restart(enum reboot_mode reboot_mode, const char *cmd)
-{
-	/*
-	 * Perform a hardware reset with the use of the Watchdog timer.
-	 */
-	at91_st_write(AT91_ST_WDMR, AT91_ST_RSTEN | AT91_ST_EXTEN | 1);
-	at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
-}
-
 static void __init at91rm9200_dt_timer_init(void)
 {
 	of_clk_init(NULL);
@@ -48,7 +37,6 @@ static void __init at91rm9200_dt_device_init(void)
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 
 	arm_pm_idle = at91rm9200_idle;
-	arm_pm_restart = at91rm9200_restart;
 	at91rm9200_pm_init();
 }
 
-- 
2.1.0

[PATCH v3 6/9] ARM: at91: time: move the system timer driver to drivers/clocksource

[Alexandre Belloni]

Import at91rm9200_time.c from mach-at91 as timer-atmel-st.c. Further cleanup is
required to get rid of the mach-at91 headers.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 arch/arm/mach-at91/Makefile                                           | 2 +-
 drivers/clocksource/Kconfig                                           | 4 ++++
 drivers/clocksource/Makefile                                          | 1 +
 .../at91rm9200_time.c => drivers/clocksource/timer-atmel-st.c         | 0
 4 files changed, 6 insertions(+), 1 deletion(-)
 rename arch/arm/mach-at91/at91rm9200_time.c => drivers/clocksource/timer-atmel-st.c (100%)

diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile
index 827fdbcce1c7..963c29169242 100644
--- a/arch/arm/mach-at91/Makefile
+++ b/arch/arm/mach-at91/Makefile
@@ -7,7 +7,7 @@ obj-y		:= setup.o
 obj-$(CONFIG_SOC_AT91SAM9)	+= sam9_smc.o
 
 # CPU-specific support
-obj-$(CONFIG_SOC_AT91RM9200)	+= at91rm9200.o at91rm9200_time.o
+obj-$(CONFIG_SOC_AT91RM9200)	+= at91rm9200.o
 obj-$(CONFIG_SOC_AT91SAM9)	+= at91sam9.o
 obj-$(CONFIG_SOC_SAMA5)		+= sama5.o
 
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 1c2506f68122..d1d15985a4ec 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -138,6 +138,10 @@ config ATMEL_PIT
 	select CLKSRC_OF if OF
 	def_bool SOC_AT91SAM9 || SOC_SAMA5
 
+config ATMEL_ST
+	select CLKSRC_OF if OF
+	def_bool SOC_AT91RM9200
+
 config CLKSRC_METAG_GENERIC
 	def_bool y if METAG
 	help
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 752d5c70b0ef..5b85f6adb258 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -1,5 +1,6 @@
 obj-$(CONFIG_CLKSRC_OF)	+= clksrc-of.o
 obj-$(CONFIG_ATMEL_PIT)		+= timer-atmel-pit.o
+obj-$(CONFIG_ATMEL_ST)		+= timer-atmel-st.o
 obj-$(CONFIG_ATMEL_TCB_CLKSRC)	+= tcb_clksrc.o
 obj-$(CONFIG_X86_PM_TIMER)	+= acpi_pm.o
 obj-$(CONFIG_SCx200HR_TIMER)	+= scx200_hrt.o
diff --git a/arch/arm/mach-at91/at91rm9200_time.c b/drivers/clocksource/timer-atmel-st.c
similarity index 100%
rename from arch/arm/mach-at91/at91rm9200_time.c
rename to drivers/clocksource/timer-atmel-st.c
-- 
2.1.0

[PATCH v3 7/9] clocksource: atmel-st: properly initialize driver

[Alexandre Belloni]

Use clocksource_of_init to initialize the system timer instead of relying on a
custom function.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 arch/arm/mach-at91/at91rm9200.c      | 7 -------
 arch/arm/mach-at91/generic.h         | 3 ---
 drivers/clocksource/timer-atmel-st.c | 4 +++-
 3 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/arch/arm/mach-at91/at91rm9200.c b/arch/arm/mach-at91/at91rm9200.c
index 2386d08d65e8..5efb075294e5 100644
--- a/arch/arm/mach-at91/at91rm9200.c
+++ b/arch/arm/mach-at91/at91rm9200.c
@@ -26,12 +26,6 @@
 
 #include "generic.h"
 
-static void __init at91rm9200_dt_timer_init(void)
-{
-	of_clk_init(NULL);
-	at91rm9200_timer_init();
-}
-
 static void __init at91rm9200_dt_device_init(void)
 {
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
@@ -48,7 +42,6 @@ static const char *at91rm9200_dt_board_compat[] __initconst = {
 };
 
 DT_MACHINE_START(at91rm9200_dt, "Atmel AT91RM9200")
-	.init_time      = at91rm9200_dt_timer_init,
 	.map_io		= at91_map_io,
 	.init_machine	= at91rm9200_dt_device_init,
 	.dt_compat	= at91rm9200_dt_board_compat,
diff --git a/arch/arm/mach-at91/generic.h b/arch/arm/mach-at91/generic.h
index 583369ffc284..6c953bff13d6 100644
--- a/arch/arm/mach-at91/generic.h
+++ b/arch/arm/mach-at91/generic.h
@@ -18,9 +18,6 @@
 extern void __init at91_map_io(void);
 extern void __init at91_alt_map_io(void);
 
- /* Timer */
-extern void at91rm9200_timer_init(void);
-
 /* idle */
 extern void at91rm9200_idle(void);
 extern void at91sam9_idle(void);
diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksource/timer-atmel-st.c
index b00d09555f2b..7d062ab32674 100644
--- a/drivers/clocksource/timer-atmel-st.c
+++ b/drivers/clocksource/timer-atmel-st.c
@@ -222,7 +222,7 @@ err:
 /*
  * ST (system timer) module supports both clockevents and clocksource.
  */
-void __init at91rm9200_timer_init(void)
+static void __init atmel_st_timer_init(struct device_node *node)
 {
 	/* For device tree enabled device: initialize here */
 	of_at91rm9200_st_init();
@@ -249,3 +249,5 @@ void __init at91rm9200_timer_init(void)
 	/* register clocksource */
 	clocksource_register_hz(&clk32k, AT91_SLOW_CLOCK);
 }
+CLOCKSOURCE_OF_DECLARE(atmel_st_timer, "atmel,at91rm9200-st",
+		       atmel_st_timer_init);
-- 
2.1.0

[PATCH v3 8/9] clocksource: atmel-st: use syscon/regmap

[Alexandre Belloni]

The register range from the system timer is also used by the watchdog driver.
Use a regmap to handle concurrent accesses.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 drivers/clocksource/timer-atmel-st.c | 99 ++++++++++++++----------------------
 1 file changed, 37 insertions(+), 62 deletions(-)

diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksource/timer-atmel-st.c
index 7d062ab32674..c4a52e32675e 100644
--- a/drivers/clocksource/timer-atmel-st.c
+++ b/drivers/clocksource/timer-atmel-st.c
@@ -24,19 +24,19 @@
 #include <linux/irq.h>
 #include <linux/clockchips.h>
 #include <linux/export.h>
-#include <linux/of.h>
-#include <linux/of_address.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/atmel-st.h>
 #include <linux/of_irq.h>
+#include <linux/regmap.h>
 
 #include <asm/mach/time.h>
 
-#include <mach/at91_st.h>
-#include <mach/hardware.h>
-
 static unsigned long last_crtr;
 static u32 irqmask;
 static struct clock_event_device clkevt;
+static struct regmap *regmap_st;
 
+#define AT91_SLOW_CLOCK		32768
 #define RM9200_TIMER_LATCH	((AT91_SLOW_CLOCK + HZ/2) / HZ)
 
 /*
@@ -46,11 +46,11 @@ static struct clock_event_device clkevt;
  */
 static inline unsigned long read_CRTR(void)
 {
-	unsigned long x1, x2;
+	unsigned int x1, x2;
 
-	x1 = at91_st_read(AT91_ST_CRTR);
+	regmap_read(regmap_st, AT91_ST_CRTR, &x1);
 	do {
-		x2 = at91_st_read(AT91_ST_CRTR);
+		regmap_read(regmap_st, AT91_ST_CRTR, &x2);
 		if (x1 == x2)
 			break;
 		x1 = x2;
@@ -63,7 +63,10 @@ static inline unsigned long read_CRTR(void)
  */
 static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id)
 {
-	u32	sr = at91_st_read(AT91_ST_SR) & irqmask;
+	u32 sr;
+
+	regmap_read(regmap_st, AT91_ST_SR, &sr);
+	sr &= irqmask;
 
 	/*
 	 * irqs should be disabled here, but as the irq is shared they are only
@@ -96,7 +99,7 @@ static struct irqaction at91rm9200_timer_irq = {
 	.name		= "at91_tick",
 	.flags		= IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
 	.handler	= at91rm9200_timer_interrupt,
-	.irq		= NR_IRQS_LEGACY + AT91_ID_SYS,
+	.irq		= 0,
 };
 
 static cycle_t read_clk32k(struct clocksource *cs)
@@ -115,23 +118,25 @@ static struct clocksource clk32k = {
 static void
 clkevt32k_mode(enum clock_event_mode mode, struct clock_event_device *dev)
 {
+	unsigned int val;
+
 	/* Disable and flush pending timer interrupts */
-	at91_st_write(AT91_ST_IDR, AT91_ST_PITS | AT91_ST_ALMS);
-	at91_st_read(AT91_ST_SR);
+	regmap_write(regmap_st, AT91_ST_IDR, AT91_ST_PITS | AT91_ST_ALMS);
+	regmap_read(regmap_st, AT91_ST_SR, &val);
 
 	last_crtr = read_CRTR();
 	switch (mode) {
 	case CLOCK_EVT_MODE_PERIODIC:
 		/* PIT for periodic irqs; fixed rate of 1/HZ */
 		irqmask = AT91_ST_PITS;
-		at91_st_write(AT91_ST_PIMR, RM9200_TIMER_LATCH);
+		regmap_write(regmap_st, AT91_ST_PIMR, RM9200_TIMER_LATCH);
 		break;
 	case CLOCK_EVT_MODE_ONESHOT:
 		/* ALM for oneshot irqs, set by next_event()
 		 * before 32 seconds have passed
 		 */
 		irqmask = AT91_ST_ALMS;
-		at91_st_write(AT91_ST_RTAR, last_crtr);
+		regmap_write(regmap_st, AT91_ST_RTAR, last_crtr);
 		break;
 	case CLOCK_EVT_MODE_SHUTDOWN:
 	case CLOCK_EVT_MODE_UNUSED:
@@ -139,7 +144,7 @@ clkevt32k_mode(enum clock_event_mode mode, struct clock_event_device *dev)
 		irqmask = 0;
 		break;
 	}
-	at91_st_write(AT91_ST_IER, irqmask);
+	regmap_write(regmap_st, AT91_ST_IER, irqmask);
 }
 
 static int
@@ -147,6 +152,7 @@ clkevt32k_next_event(unsigned long delta, struct clock_event_device *dev)
 {
 	u32		alm;
 	int		status = 0;
+	unsigned int	val;
 
 	BUG_ON(delta < 2);
 
@@ -162,12 +168,12 @@ clkevt32k_next_event(unsigned long delta, struct clock_event_device *dev)
 	alm = read_CRTR();
 
 	/* Cancel any pending alarm; flush any pending IRQ */
-	at91_st_write(AT91_ST_RTAR, alm);
-	at91_st_read(AT91_ST_SR);
+	regmap_write(regmap_st, AT91_ST_RTAR, alm);
+	regmap_read(regmap_st, AT91_ST_SR, &val);
 
 	/* Schedule alarm by writing RTAR. */
 	alm += delta;
-	at91_st_write(AT91_ST_RTAR, alm);
+	regmap_write(regmap_st, AT91_ST_RTAR, alm);
 
 	return status;
 }
@@ -180,57 +186,26 @@ static struct clock_event_device clkevt = {
 	.set_mode	= clkevt32k_mode,
 };
 
-void __iomem *at91_st_base;
-EXPORT_SYMBOL_GPL(at91_st_base);
-
-static const struct of_device_id at91rm9200_st_timer_ids[] = {
-	{ .compatible = "atmel,at91rm9200-st" },
-	{ /* sentinel */ }
-};
-
-static int __init of_at91rm9200_st_init(void)
-{
-	struct device_node *np;
-	int ret;
-
-	np = of_find_matching_node(NULL, at91rm9200_st_timer_ids);
-	if (!np)
-		goto err;
-
-	at91_st_base = of_iomap(np, 0);
-	if (!at91_st_base)
-		goto node_err;
-
-	/* Get the interrupts property */
-	ret = irq_of_parse_and_map(np, 0);
-	if (!ret)
-		goto ioremap_err;
-	at91rm9200_timer_irq.irq = ret;
-
-	of_node_put(np);
-
-	return 0;
-
-ioremap_err:
-	iounmap(at91_st_base);
-node_err:
-	of_node_put(np);
-err:
-	return -EINVAL;
-}
-
 /*
  * ST (system timer) module supports both clockevents and clocksource.
  */
 static void __init atmel_st_timer_init(struct device_node *node)
 {
-	/* For device tree enabled device: initialize here */
-	of_at91rm9200_st_init();
+	unsigned int val;
+
+	regmap_st = syscon_node_to_regmap(node);
+	if (IS_ERR(regmap_st))
+		panic(pr_fmt("Unable to get regmap\n"));
 
 	/* Disable all timer interrupts, and clear any pending ones */
-	at91_st_write(AT91_ST_IDR,
+	regmap_write(regmap_st, AT91_ST_IDR,
 		AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS);
-	at91_st_read(AT91_ST_SR);
+	regmap_read(regmap_st, AT91_ST_SR, &val);
+
+	/* Get the interrupts property */
+	at91rm9200_timer_irq.irq  = irq_of_parse_and_map(node, 0);
+	if (!at91rm9200_timer_irq.irq)
+		panic(pr_fmt("Unable to get IRQ from DT\n"));
 
 	/* Make IRQs happen for the system timer */
 	setup_irq(at91rm9200_timer_irq.irq, &at91rm9200_timer_irq);
@@ -239,7 +214,7 @@ static void __init atmel_st_timer_init(struct device_node *node)
 	 * directly for the clocksource and all clockevents, after adjusting
 	 * its prescaler from the 1 Hz default.
 	 */
-	at91_st_write(AT91_ST_RTMR, 1);
+	regmap_write(regmap_st, AT91_ST_RTMR, 1);
 
 	/* Setup timer clockevent, with minimum of two ticks (important!!) */
 	clkevt.cpumask = cpumask_of(0);
-- 
2.1.0

[PATCH v3 9/9] ARM: at91: remove useless include

[Alexandre Belloni]

Both drivers using the system timer are now converted to an MFD. mach/at91_st.h
is now useless.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 arch/arm/mach-at91/include/mach/at91_st.h | 61 -------------------------------
 1 file changed, 61 deletions(-)
 delete mode 100644 arch/arm/mach-at91/include/mach/at91_st.h

diff --git a/arch/arm/mach-at91/include/mach/at91_st.h b/arch/arm/mach-at91/include/mach/at91_st.h
deleted file mode 100644
index 67fdbd13c3ed..000000000000
--- a/arch/arm/mach-at91/include/mach/at91_st.h
+++ /dev/null
@@ -1,61 +0,0 @@
-/*
- * arch/arm/mach-at91/include/mach/at91_st.h
- *
- * Copyright (C) 2005 Ivan Kokshaysky
- * Copyright (C) SAN People
- *
- * System Timer (ST) - System peripherals registers.
- * Based on AT91RM9200 datasheet revision E.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- */
-
-#ifndef AT91_ST_H
-#define AT91_ST_H
-
-#ifndef __ASSEMBLY__
-extern void __iomem *at91_st_base;
-
-#define at91_st_read(field) \
-	__raw_readl(at91_st_base + field)
-
-#define at91_st_write(field, value) \
-	__raw_writel(value, at91_st_base + field)
-#else
-.extern at91_st_base
-#endif
-
-#define	AT91_ST_CR		0x00			/* Control Register */
-#define 	AT91_ST_WDRST		(1 << 0)		/* Watchdog Timer Restart */
-
-#define	AT91_ST_PIMR		0x04			/* Period Interval Mode Register */
-#define		AT91_ST_PIV		(0xffff <<  0)		/* Period Interval Value */
-
-#define	AT91_ST_WDMR		0x08			/* Watchdog Mode Register */
-#define		AT91_ST_WDV		(0xffff <<  0)		/* Watchdog Counter Value */
-#define		AT91_ST_RSTEN		(1	<< 16)		/* Reset Enable */
-#define		AT91_ST_EXTEN		(1	<< 17)		/* External Signal Assertion Enable */
-
-#define	AT91_ST_RTMR		0x0c			/* Real-time Mode Register */
-#define		AT91_ST_RTPRES		(0xffff <<  0)		/* Real-time Prescalar Value */
-
-#define	AT91_ST_SR		0x10			/* Status Register */
-#define		AT91_ST_PITS		(1 << 0)		/* Period Interval Timer Status */
-#define		AT91_ST_WDOVF		(1 << 1) 		/* Watchdog Overflow */
-#define		AT91_ST_RTTINC		(1 << 2) 		/* Real-time Timer Increment */
-#define		AT91_ST_ALMS		(1 << 3) 		/* Alarm Status */
-
-#define	AT91_ST_IER		0x14			/* Interrupt Enable Register */
-#define	AT91_ST_IDR		0x18			/* Interrupt Disable Register */
-#define	AT91_ST_IMR		0x1c			/* Interrupt Mask Register */
-
-#define	AT91_ST_RTAR		0x20			/* Real-time Alarm Register */
-#define		AT91_ST_ALMV		(0xfffff << 0)		/* Alarm Value */
-
-#define	AT91_ST_CRTR		0x24			/* Current Real-time Register */
-#define		AT91_ST_CRTV		(0xfffff << 0)		/* Current Real-Time Value */
-
-#endif
-- 
2.1.0

Re: [PATCH v3 3/9] watchdog: at91rm9200: use the system timer syscon

[Guenter Roeck]

On 03/04/2015 06:21 AM, Alexandre Belloni wrote:
> Use a syscon regmap to access the systemr timer registers.
>
s/systemr/system/

> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
...
>
>   static const struct of_device_id at91_wdt_dt_ids[] = {
> +	{ .compatible = "atmel,at91rm9200-st" },
>   	{ .compatible = "atmel,at91rm9200-wdt" },
>   	{ /* sentinel */ }
>   };
> @@ -267,7 +276,7 @@ static struct platform_driver at91wdt_driver = {
>   	.suspend	= at91wdt_suspend,
>   	.resume		= at91wdt_resume,
>   	.driver		= {
> -		.name	= "at91_wdt",
> +		.name	= "atmel_st_watchdog",

If you change the driver name you also need to change the MODULE_ALIAS
a few lines down.

But why change it in the first place ? Maybe that was discussed somewhere,
but not here where it belongs, and not in patch 0/9 either.

Guenter

Re: [PATCH v3 3/9] watchdog: at91rm9200: use the system timer syscon

[Alexandre Belloni]

On 04/03/2015 at 06:51:51 -0800, Guenter Roeck wrote :
> >@@ -267,7 +276,7 @@ static struct platform_driver at91wdt_driver = {
> >  	.suspend	= at91wdt_suspend,
> >  	.resume		= at91wdt_resume,
> >  	.driver		= {
> >-		.name	= "at91_wdt",
> >+		.name	= "atmel_st_watchdog",
> 
> If you change the driver name you also need to change the MODULE_ALIAS
> a few lines down.
> 
> But why change it in the first place ? Maybe that was discussed somewhere,
> but not here where it belongs, and not in patch 0/9 either.
> 

That's because it conflicts with drivers/watchdog/at91sam9_wdt.c

I'm not sure that is relevant anymore as they will only be probed using
DT now.


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

Re: [PATCH v3 2/9] mfd: syscon: Add atmel system timer registers definition

[Lee Jones]

On Wed, 04 Mar 2015, Alexandre Belloni wrote:

> AT91RM920 has a memory range reserved for timer and watchdog configuration.
> Expose those registers so that drivers can make use of the system timer syscon
> declared in at91 DTs.
> 
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
>  include/linux/mfd/syscon/atmel-st.h | 47 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 47 insertions(+)
>  create mode 100644 include/linux/mfd/syscon/atmel-st.h
> 
> diff --git a/include/linux/mfd/syscon/atmel-st.h b/include/linux/mfd/syscon/atmel-st.h
> new file mode 100644
> index 000000000000..8e29a1028807
> --- /dev/null
> +++ b/include/linux/mfd/syscon/atmel-st.h
> @@ -0,0 +1,47 @@
> +/*
> + * Copyright (C) 2005 Ivan Kokshaysky
> + * Copyright (C) SAN People
> + *
> + * System Timer (ST) - System peripherals registers.
> + * Based on AT91RM9200 datasheet revision E.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#ifndef _LINUX_MFD_SYSCON_ATMEL_ST_H
> +#define _LINUX_MFD_SYSCON_ATMEL_ST_H
> +
> +#define	AT91_ST_CR	0x00	/* Control Register */
> +#define		AT91_ST_WDRST	(1 << 0)	/* Watchdog Timer Restart */

Please use BIT() for "1 <<".

> +#define	AT91_ST_PIMR	0x04	/* Period Interval Mode Register */
> +#define		AT91_ST_PIV	(0xffff <<  0)	/* Period Interval Value */
> +
> +#define	AT91_ST_WDMR	0x08	/* Watchdog Mode Register */
> +#define		AT91_ST_WDV	(0xffff <<  0)	/* Watchdog Counter Value */
> +#define		AT91_ST_RSTEN	(1 << 16)	/* Reset Enable */
> +#define		AT91_ST_EXTEN	(1 << 17)	/* External Signal Assertion Enable */
> +
> +#define	AT91_ST_RTMR	0x0c	/* Real-time Mode Register */
> +#define		AT91_ST_RTPRES	(0xffff <<  0)	/* Real-time Prescalar Value */
> +
> +#define	AT91_ST_SR	0x10	/* Status Register */
> +#define		AT91_ST_PITS	(1 << 0)	/* Period Interval Timer Status */
> +#define		AT91_ST_WDOVF	(1 << 1)	/* Watchdog Overflow */
> +#define		AT91_ST_RTTINC	(1 << 2)	/* Real-time Timer Increment */
> +#define		AT91_ST_ALMS	(1 << 3)	/* Alarm Status */
> +
> +#define	AT91_ST_IER	0x14	/* Interrupt Enable Register */
> +#define	AT91_ST_IDR	0x18	/* Interrupt Disable Register */
> +#define	AT91_ST_IMR	0x1c	/* Interrupt Mask Register */
> +
> +#define	AT91_ST_RTAR	0x20	/* Real-time Alarm Register */
> +#define		AT91_ST_ALMV	(0xfffff << 0)	/* Alarm Value */
> +
> +#define	AT91_ST_CRTR	0x24	/* Current Real-time Register */
> +#define		AT91_ST_CRTV	(0xfffff << 0)	/* Current Real-Time Value */
> +
> +#endif /* _LINUX_MFD_SYSCON_ATMEL_ST_H */

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

Re: [PATCH v3 4/9] power: reset: Add AT91RM9200 reset driver

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 599 bytes --]

Hi,

On Wed, Mar 04, 2015 at 03:21:32PM +0100, Alexandre Belloni wrote:
> AT91RM9200 uses the watchdog from the system timer to reset.
> [...]
> +	regmap_write(regmap_st, AT91_ST_WDMR,
> +		     AT91_ST_RSTEN | AT91_ST_EXTEN | 1);
> +	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
> +
> +	mdelay(2000);

At pity that you have to write into two registers, otherwise you
could have used the syscon-reboot driver.

> [...]
> +module_platform_driver(at91rm9200_reset_driver);

Apart from missing module metadata (MODULE_AUTHOR(),
MODULE_LICENSE(), ...) the driver looks fine to me.

-- Sebastian


[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

Re: [PATCH v3 3/9] watchdog: at91rm9200: use the system timer syscon

[Guenter Roeck]

On Wed, Mar 04, 2015 at 04:08:15PM +0100, Alexandre Belloni wrote:
> On 04/03/2015 at 06:51:51 -0800, Guenter Roeck wrote :
> > >@@ -267,7 +276,7 @@ static struct platform_driver at91wdt_driver = {
> > >  	.suspend	= at91wdt_suspend,
> > >  	.resume		= at91wdt_resume,
> > >  	.driver		= {
> > >-		.name	= "at91_wdt",
> > >+		.name	= "atmel_st_watchdog",
> > 
> > If you change the driver name you also need to change the MODULE_ALIAS
> > a few lines down.
> > 
> > But why change it in the first place ? Maybe that was discussed somewhere,
> > but not here where it belongs, and not in patch 0/9 either.
> > 
> 
> That's because it conflicts with drivers/watchdog/at91sam9_wdt.c
> 
You still have to update MODULE_ALIAS (or drop it if it is not needed anymore).

Guenter

> I'm not sure that is relevant anymore as they will only be probed using
> DT now.
> 
> 
> -- 
> Alexandre Belloni, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com

Re: [PATCH v3 4/9] power: reset: Add AT91RM9200 reset driver

[Alexandre Belloni]

On 04/03/2015 at 18:17:58 +0100, Sebastian Reichel wrote :
> Hi,
> 
> On Wed, Mar 04, 2015 at 03:21:32PM +0100, Alexandre Belloni wrote:
> > AT91RM9200 uses the watchdog from the system timer to reset.
> > [...]
> > +	regmap_write(regmap_st, AT91_ST_WDMR,
> > +		     AT91_ST_RSTEN | AT91_ST_EXTEN | 1);
> > +	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
> > +
> > +	mdelay(2000);
> 
> At pity that you have to write into two registers, otherwise you
> could have used the syscon-reboot driver.
> 

Exactly what I was thinking :)

> > [...]
> > +module_platform_driver(at91rm9200_reset_driver);
> 
> Apart from missing module metadata (MODULE_AUTHOR(),
> MODULE_LICENSE(), ...) the driver looks fine to me.
> 

I'll add those.

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