[PATCH 0/8] ARM RealView DeviceTree support v5

[PATCH 0/8] ARM RealView DeviceTree support v5

[Linus Walleij]

I've updated the RealView DeviceTree patch.

Main changes:
- Push l2x0 setup into the device tree
- Abstractify syscon LEDs
- Abstractify syscon reboot

Florian Fainelli (1):
  ARM: l2c: parse 'cache-size' and 'cache-sets' properties

Linus Walleij (7):
  leds: add a driver for syscon-based LEDs
  leds: add device tree bindings for register bit LEDs
  power: reset: driver for the Versatile syscon reboot
  soc: add driver for the ARM RealView
  ARM: l2x0: move DT parsing for cache props
  ARM: l2x0: support associativity from DT
  ARM: realview: basic device tree implementation

 Documentation/devicetree/bindings/arm/arm-boards   |  65 ++++++
 Documentation/devicetree/bindings/arm/gic.txt      |   1 +
 Documentation/devicetree/bindings/arm/l2cc.txt     |   3 +
 .../devicetree/bindings/leds/register-bit-led.txt  |  99 +++++++++
 arch/arm/boot/dts/Makefile                         |   1 +
 arch/arm/boot/dts/arm-realview-pb1176.dts          | 246 +++++++++++++++++++++
 arch/arm/mach-realview/Kconfig                     |  13 ++
 arch/arm/mach-realview/Makefile                    |   1 +
 arch/arm/mach-realview/realview-dt.c               |  47 ++++
 arch/arm/mm/cache-l2x0.c                           |  82 ++++++-
 drivers/irqchip/irq-gic.c                          |   2 +
 drivers/leds/Kconfig                               |  10 +
 drivers/leds/Makefile                              |   1 +
 drivers/leds/leds-syscon.c                         | 165 ++++++++++++++
 drivers/power/reset/Kconfig                        |   9 +
 drivers/power/reset/Makefile                       |   1 +
 drivers/power/reset/arm-versatile-reboot.c         | 111 ++++++++++
 drivers/soc/Kconfig                                |   1 +
 drivers/soc/Makefile                               |   1 +
 drivers/soc/versatile/Kconfig                      |  10 +
 drivers/soc/versatile/Makefile                     |   1 +
 drivers/soc/versatile/soc-realview.c               | 144 ++++++++++++
 22 files changed, 1009 insertions(+), 5 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/leds/register-bit-led.txt
 create mode 100644 arch/arm/boot/dts/arm-realview-pb1176.dts
 create mode 100644 arch/arm/mach-realview/realview-dt.c
 create mode 100644 drivers/leds/leds-syscon.c
 create mode 100644 drivers/power/reset/arm-versatile-reboot.c
 create mode 100644 drivers/soc/versatile/Kconfig
 create mode 100644 drivers/soc/versatile/Makefile
 create mode 100644 drivers/soc/versatile/soc-realview.c

-- 
1.9.3

[PATCH 1/8 v2] leds: add a driver for syscon-based LEDs

[Linus Walleij]

This makes it possible to create a set of LEDs from a syscon
MFD instance, which is lean mean and clean on the ARM
reference designs and can replace the Versatile LEDs driver
in the long run, as well as other custom syscon LEDs drivers.

Cc: Bryan Wu <cooloney@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v1->v2:
- Augment driver to probe all nodes of a syscon to see if they
  are "register-bit-led"s, and then allocate them under the syscon
  if that is the case.
- Switch compatible string from "syscon-leds" to "register-bit-led"
---
 drivers/leds/Kconfig       |  10 +++
 drivers/leds/Makefile      |   1 +
 drivers/leds/leds-syscon.c | 165 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 176 insertions(+)
 create mode 100644 drivers/leds/leds-syscon.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 8c96e2ddf43b..ea05b6e2ea58 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -478,6 +478,16 @@ config LEDS_BLINKM
 	  This option enables support for the BlinkM RGB LED connected
 	  through I2C. Say Y to enable support for the BlinkM LED.
 
+config LEDS_SYSCON
+	bool "LED support for LEDs on system controllers"
+	depends on LEDS_CLASS
+	depends on MFD_SYSCON
+	depends on OF
+	help
+	  This option enabled support for the LEDs on syscon type
+	  devices. This will only work with device tree enabled
+	  devices.
+
 config LEDS_VERSATILE
 	tristate "LED support for the ARM Versatile and RealView"
 	depends on ARCH_REALVIEW || ARCH_VERSATILE
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index d8cc5f2777de..822dd83ef97a 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_LEDS_ASIC3)		+= leds-asic3.o
 obj-$(CONFIG_LEDS_MAX8997)		+= leds-max8997.o
 obj-$(CONFIG_LEDS_LM355x)		+= leds-lm355x.o
 obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
+obj-$(CONFIG_LEDS_SYSCON)		+= leds-syscon.o
 obj-$(CONFIG_LEDS_VERSATILE)		+= leds-versatile.o
 
 # LED SPI Drivers
diff --git a/drivers/leds/leds-syscon.c b/drivers/leds/leds-syscon.c
new file mode 100644
index 000000000000..b6174f421ef2
--- /dev/null
+++ b/drivers/leds/leds-syscon.c
@@ -0,0 +1,165 @@
+/*
+ * Generic Syscon LEDs Driver
+ *
+ * Copyright (c) 2014, Linaro Limited
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ * This driver provides system reboot functionality for APM X-Gene SoC.
+ * For system shutdown, this is board specify. If a board designer
+ * implements GPIO shutdown, use the gpio-poweroff.c driver.
+ */
+#include <linux/io.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/leds.h>
+
+/**
+ * struct syscon_led - state container for syscon based LEDs
+ * @cdev: LED class device for this LED
+ * @map: regmap to access the syscon device backing this LED
+ * @offset: the offset into the syscon regmap for the LED register
+ * @mask: the bit in the register corresponding to the LED
+ * @state: current state of the LED
+ */
+struct syscon_led {
+	struct led_classdev cdev;
+	struct regmap *map;
+	u32 offset;
+	u32 mask;
+	bool state;
+};
+
+static void syscon_led_set(struct led_classdev *led_cdev,
+	enum led_brightness value)
+{
+	struct syscon_led *sled =
+		container_of(led_cdev, struct syscon_led, cdev);
+	u32 val;
+	int ret;
+
+	if (value == LED_OFF) {
+		val = 0;
+		sled->state = false;
+	} else {
+		val = sled->mask;
+		sled->state = true;
+	}
+
+	ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val);
+	if (ret < 0)
+		dev_err(sled->cdev.dev, "error updating LED status\n");
+}
+
+static const struct of_device_id syscon_match[] = {
+	{ .compatible = "syscon", },
+};
+
+static int __init syscon_leds_init(void)
+{
+	const struct of_device_id *devid;
+	struct device_node *np;
+	struct device_node *child;
+	struct regmap *map;
+	struct platform_device *pdev;
+	struct device *dev;
+	int ret;
+
+	np = of_find_matching_node_and_match(NULL, syscon_match,
+					     &devid);
+	if (!np)
+		return -ENODEV;
+
+	map = syscon_node_to_regmap(np);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	/*
+	 * If the map is there, the device should be there, we allocate
+	 * memory on the syscon device's behalf here.
+	 */
+	pdev = of_find_device_by_node(np);
+	if (!pdev)
+		return -ENODEV;
+	dev = &pdev->dev;
+
+	for_each_available_child_of_node(np, child) {
+		struct syscon_led *sled;
+		const char *state;
+
+		/* Only check for register-bit-leds */
+		if (of_property_match_string(child, "compatible",
+					     "register-bit-led") < 0)
+			continue;
+
+		sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
+		if (!sled)
+			return -ENOMEM;
+
+		sled->map = map;
+
+		if (of_property_read_u32(child, "offset", &sled->offset))
+			return -EINVAL;
+		if (of_property_read_u32(child, "mask", &sled->mask))
+			return -EINVAL;
+		sled->cdev.name =
+			of_get_property(child, "label", NULL) ? : child->name;
+		sled->cdev.default_trigger =
+			of_get_property(child, "linux,default-trigger", NULL);
+
+		state = of_get_property(child, "default-state", NULL);
+		if (state) {
+			if (!strcmp(state, "keep")) {
+				u32 val;
+
+				ret = regmap_read(map, sled->offset, &val);
+				if (ret < 0)
+					return ret;
+				sled->state = !!(val & sled->mask);
+			} else if (!strcmp(state, "on")) {
+				sled->state = true;
+				ret = regmap_update_bits(map, sled->offset,
+							 sled->mask,
+							 sled->mask);
+				if (ret < 0)
+					return ret;
+			} else {
+				sled->state = false;
+				ret = regmap_update_bits(map, sled->offset,
+							 sled->mask, 0);
+				if (ret < 0)
+					return ret;
+			}
+
+		}
+		sled->cdev.brightness_set = syscon_led_set;
+
+		ret = led_classdev_register(dev, &sled->cdev);
+		if (ret < 0)
+			return ret;
+
+		dev_info(dev, "registered LED %s\n", sled->cdev.name);
+	}
+
+       return 0;
+}
+device_initcall(syscon_leds_init);
-- 
1.9.3

[PATCH 2/8 v2] leds: add device tree bindings for register bit LEDs

[Linus Walleij]

This adds the device tree bindings used by register bit LEDs.

Cc: devicetree at vger.kernel.org
Cc: Bryan Wu <cooloney@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v1->v2:
- Rename binding "register-bit-led"
- Define that such nodes appear only as children of syscon
- Group required and optional parameters
- Number nodes as foo@<offset>.<bit>
- Update example
---
 .../devicetree/bindings/leds/register-bit-led.txt  | 99 ++++++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/register-bit-led.txt

diff --git a/Documentation/devicetree/bindings/leds/register-bit-led.txt b/Documentation/devicetree/bindings/leds/register-bit-led.txt
new file mode 100644
index 000000000000..379cefdc0bda
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/register-bit-led.txt
@@ -0,0 +1,99 @@
+Device Tree Bindings for Register Bit LEDs
+
+Register bit leds are used with syscon multifunctional devices
+where single bits in a certain register can turn on/off a
+single LED. The register bit LEDs appear as children to the
+syscon device, with the proper compatible string. For the
+syscon bindings see:
+Documentation/devicetree/bindings/mfd/syscon.txt
+
+Each LED is represented as a sub-node of the syscon device. Each
+node's name represents the name of the corresponding LED.
+
+LED sub-node properties:
+
+Required properties:
+- compatible : must be "register-bit-led"
+- offset : register offset to the register controlling this LED
+- mask : bit mask for the bit controlling this LED in the register
+  typically 0x01, 0x02, 0x04 ...
+
+Optional properties:
+- label : (optional)
+  see Documentation/devicetree/bindings/leds/common.txt
+- linux,default-trigger : (optional)
+  see Documentation/devicetree/bindings/leds/common.txt
+- default-state: (optional) The initial state of the LED. Valid
+  values are "on", "off", and "keep". If the LED is already on or off
+  and the default-state property is set the to same value, then no
+  glitch should be produced where the LED momentarily turns off (or
+  on). The "keep" setting will keep the LED at whatever its current
+  state is, without producing a glitch.  The default is off if this
+  property is not present.
+
+Example:
+
+syscon: syscon at 10000000 {
+	compatible = "arm,realview-pb1176-syscon", "syscon";
+	reg = <0x10000000 0x1000>;
+
+	led at 08.0 {
+		compatible = "register-bit-led";
+		offset = <0x08>;
+		mask = <0x01>;
+		label = "versatile:0";
+		linux,default-trigger = "heartbeat";
+		default-state = "on";
+	};
+	led at 08.1 {
+		compatible = "register-bit-led";
+		offset = <0x08>;
+		mask = <0x02>;
+		label = "versatile:1";
+		linux,default-trigger = "mmc0";
+		default-state = "off";
+	};
+	led at 08.2 {
+		compatible = "register-bit-led";
+		offset = <0x08>;
+		mask = <0x04>;
+		label = "versatile:2";
+		linux,default-trigger = "cpu0";
+		default-state = "off";
+	};
+	led at 08.3 {
+		compatible = "register-bit-led";
+		offset = <0x08>;
+		mask = <0x08>;
+		label = "versatile:3";
+		default-state = "off";
+	};
+	led at 08.4 {
+		compatible = "register-bit-led";
+		offset = <0x08>;
+		mask = <0x10>;
+		label = "versatile:4";
+		default-state = "off";
+	};
+	led at 08.5 {
+		compatible = "register-bit-led";
+		offset = <0x08>;
+		mask = <0x20>;
+		label = "versatile:5";
+		default-state = "off";
+	};
+	led at 08.6 {
+		compatible = "register-bit-led";
+		offset = <0x08>;
+		mask = <0x40>;
+		label = "versatile:6";
+		default-state = "off";
+	};
+	led at 08.7 {
+		compatible = "register-bit-led";
+		offset = <0x08>;
+		mask = <0x80>;
+		label = "versatile:7";
+		default-state = "off";
+	};
+};
-- 
1.9.3

[PATCH 3/8 v2] power: reset: driver for the Versatile syscon reboot

[Linus Walleij]

This driver enabled us to drive the reboot of the Versatile family
of ARM reference boards. Even though only the RealView boards are
supported initially, these boards all have the same procedure for
reboot:

- Write a magic value into an unlocking register
- Write another magic value into a reset control register

The driver will be reusable for Versatile and possibly also the
Integrator family of reference boards.

Cc: Sebastian Reichel <sre@kernel.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v1->v2:
- Do not probe from a platform device, instead use a device_initcall()
  and look up the syscon device from its node. If that device is
  not yet registered, the call will be deferred. This is done so that
  the Linux driver model is not reflected into the device tree, as
  the reboot property of the syscon is not a separate device.
---
 drivers/power/reset/Kconfig                |   9 +++
 drivers/power/reset/Makefile               |   1 +
 drivers/power/reset/arm-versatile-reboot.c | 111 +++++++++++++++++++++++++++++
 3 files changed, 121 insertions(+)
 create mode 100644 drivers/power/reset/arm-versatile-reboot.c

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index ca41523bbebf..2447c76e2f1a 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -75,6 +75,15 @@ config POWER_RESET_SUN6I
 	help
 	  Reboot support for the Allwinner A31 SoCs.
 
+config POWER_RESET_VERSATILE
+	bool "ARM Versatile family reboot driver"
+	depends on ARM
+	depends on MFD_SYSCON
+	depends on OF
+	help
+	  Power off and restart support for ARM Versatile family of
+	  reference boards.
+
 config POWER_RESET_VEXPRESS
 	bool "ARM Versatile Express power-off and reset driver"
 	depends on ARM || ARM64
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index a42e70edd037..41ab0e7b92b8 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
 obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
 obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
 obj-$(CONFIG_POWER_RESET_SUN6I) += sun6i-reboot.o
+obj-$(CONFIG_POWER_RESET_VERSATILE) += arm-versatile-reboot.o
 obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
 obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o
 obj-$(CONFIG_POWER_RESET_KEYSTONE) += keystone-reset.o
diff --git a/drivers/power/reset/arm-versatile-reboot.c b/drivers/power/reset/arm-versatile-reboot.c
new file mode 100644
index 000000000000..5b08bffcf1a8
--- /dev/null
+++ b/drivers/power/reset/arm-versatile-reboot.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2014 Linaro Ltd.
+ *
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/init.h>
+#include <linux/mfd/syscon.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+#include <asm/system_misc.h>
+
+#define REALVIEW_SYS_LOCK_OFFSET	0x20
+#define REALVIEW_SYS_LOCK_VAL		0xA05F
+#define REALVIEW_SYS_RESETCTL_OFFSET	0x40
+
+/*
+ * We detect the different syscon types from the compatible strings.
+ */
+enum versatile_reboot {
+	REALVIEW_REBOOT_EB,
+	REALVIEW_REBOOT_PB1176,
+	REALVIEW_REBOOT_PB11MP,
+	REALVIEW_REBOOT_PBA8,
+	REALVIEW_REBOOT_PBX,
+};
+
+/* Pointer to the system controller */
+static struct regmap *syscon_regmap;
+static enum versatile_reboot versatile_reboot_type;
+
+static const struct of_device_id versatile_reboot_of_match[] = {
+	{
+		.compatible = "arm,realview-eb-syscon",
+		.data = (void *)REALVIEW_REBOOT_EB,
+	},
+	{
+		.compatible = "arm,realview-pb1176-syscon",
+		.data = (void *)REALVIEW_REBOOT_PB1176,
+	},
+	{
+		.compatible = "arm,realview-pb11mp-syscon",
+		.data = (void *)REALVIEW_REBOOT_PB11MP,
+	},
+	{
+		.compatible = "arm,realview-pba8-syscon",
+		.data = (void *)REALVIEW_REBOOT_PBA8,
+	},
+	{
+		.compatible = "arm,realview-pbx-syscon",
+		.data = (void *)REALVIEW_REBOOT_PBX,
+	},
+};
+
+static void versatile_reboot(enum reboot_mode mode, const char *cmd)
+{
+	/* Unlock the reset register */
+	regmap_write(syscon_regmap, REALVIEW_SYS_LOCK_OFFSET,
+		     REALVIEW_SYS_LOCK_VAL);
+	/* Then hit reset on the different machines */
+	switch (versatile_reboot_type) {
+	case REALVIEW_REBOOT_EB:
+		regmap_write(syscon_regmap,
+			     REALVIEW_SYS_RESETCTL_OFFSET, 0x0008);
+		break;
+	case REALVIEW_REBOOT_PB1176:
+		regmap_write(syscon_regmap,
+			     REALVIEW_SYS_RESETCTL_OFFSET, 0x0100);
+		break;
+	case REALVIEW_REBOOT_PB11MP:
+	case REALVIEW_REBOOT_PBA8:
+		regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
+			     0x0000);
+		regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
+			     0x0004);
+		break;
+	case REALVIEW_REBOOT_PBX:
+		regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
+			     0x00f0);
+		regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
+			     0x00f4);
+		break;
+	}
+	dsb();
+}
+
+static int __init versatile_reboot_probe(void)
+{
+	const struct of_device_id *reboot_id;
+	struct device_node *np;
+
+	np = of_find_matching_node_and_match(NULL, versatile_reboot_of_match,
+						 &reboot_id);
+	if (!np)
+		return -ENODEV;
+	versatile_reboot_type = (enum versatile_reboot)reboot_id->data;
+
+	syscon_regmap = syscon_node_to_regmap(np);
+	if (IS_ERR(syscon_regmap))
+		return PTR_ERR(syscon_regmap);
+
+	arm_pm_restart = versatile_reboot;
+	pr_info("versatile reboot driver registered\n");
+	return 0;
+}
+device_initcall(versatile_reboot_probe);
-- 
1.9.3

[PATCH 4/8] soc: add driver for the ARM RealView

[Linus Walleij]

This adds a SoC driver to be used by the ARM RealView
reference boards. We create the "versatile" directory to hold
the different ARM reference designs as per the pattern of the
clk directory layout. The driver utilze the syscon to get to
the register needed. After this we can use sysfs to get at
some SoC properties on RealView DT variants like this:

> cd /sysbus/soc/devices/soc0
> ls
board         family        machine       power         subsystem
build         fpga          manufacturer  soc_id        uevent
> cat family
Versatile
> cat fpga
Multi-layer AXI
> cat board
HBI-0147
> cat build
03

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/soc/Kconfig                  |   1 +
 drivers/soc/Makefile                 |   1 +
 drivers/soc/versatile/Kconfig        |  10 +++
 drivers/soc/versatile/Makefile       |   1 +
 drivers/soc/versatile/soc-realview.c | 144 +++++++++++++++++++++++++++++++++++
 5 files changed, 157 insertions(+)
 create mode 100644 drivers/soc/versatile/Kconfig
 create mode 100644 drivers/soc/versatile/Makefile
 create mode 100644 drivers/soc/versatile/soc-realview.c

diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index c8543855aa82..6ed3590253cf 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -1,5 +1,6 @@
 menu "SOC (System On Chip) specific Drivers"
 
 source "drivers/soc/qcom/Kconfig"
+source "drivers/soc/versatile/Kconfig"
 
 endmenu
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 3b1b95d932d1..d20d8f625732 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -4,3 +4,4 @@
 
 obj-$(CONFIG_ARCH_QCOM)		+= qcom/
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
+obj-$(CONFIG_PLAT_VERSATILE)	+= versatile/
diff --git a/drivers/soc/versatile/Kconfig b/drivers/soc/versatile/Kconfig
new file mode 100644
index 000000000000..bf5ee9c85330
--- /dev/null
+++ b/drivers/soc/versatile/Kconfig
@@ -0,0 +1,10 @@
+#
+# ARM Versatile SoC drivers
+#
+config SOC_REALVIEW
+	bool "SoC bus device for the ARM RealView platforms"
+	depends on ARCH_REALVIEW
+	select SOC_BUS
+	help
+	  Include support for the SoC bus on the ARM RealView platforms
+	  providing some sysfs information about the ASIC variant.
diff --git a/drivers/soc/versatile/Makefile b/drivers/soc/versatile/Makefile
new file mode 100644
index 000000000000..ad547435648e
--- /dev/null
+++ b/drivers/soc/versatile/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_SOC_REALVIEW)	+= soc-realview.o
diff --git a/drivers/soc/versatile/soc-realview.c b/drivers/soc/versatile/soc-realview.c
new file mode 100644
index 000000000000..cea8ea3491d2
--- /dev/null
+++ b/drivers/soc/versatile/soc-realview.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2014 Linaro Ltd.
+ *
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+
+/* System ID in syscon */
+#define REALVIEW_SYS_ID_OFFSET 0x00
+
+static const struct of_device_id realview_soc_of_match[] = {
+	{ .compatible = "arm,realview-eb-soc",	},
+	{ .compatible = "arm,realview-pb1176-soc", },
+	{ .compatible = "arm,realview-pb11mp-soc", },
+	{ .compatible = "arm,realview-pba8-soc", },
+	{ .compatible = "arm,realview-pbx-soc", },
+};
+
+static u32 realview_coreid;
+
+static const char *realview_board_str(u32 id)
+{
+	switch ((id >> 16) & 0xfff) {
+	case 0x0147:
+		return "HBI-0147";
+	default:
+		return "Unknown";
+	}
+}
+
+static const char *realview_arch_str(u32 id)
+{
+	switch ((id >> 8) & 0xf) {
+	case 0x05:
+		return "Multi-layer AXI";
+	default:
+		return "Unknown";
+	}
+}
+
+static ssize_t realview_get_manf(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	return sprintf(buf, "%02x\n", realview_coreid >> 24);
+}
+
+static struct device_attribute realview_manf_attr =
+	__ATTR(manufacturer,  S_IRUGO, realview_get_manf,  NULL);
+
+static ssize_t realview_get_board(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	return sprintf(buf, "%s\n", realview_board_str(realview_coreid));
+}
+
+static struct device_attribute realview_board_attr =
+	__ATTR(board,  S_IRUGO, realview_get_board,  NULL);
+
+static ssize_t realview_get_arch(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	return sprintf(buf, "%s\n", realview_arch_str(realview_coreid));
+}
+
+static struct device_attribute realview_arch_attr =
+	__ATTR(fpga,  S_IRUGO, realview_get_arch,  NULL);
+
+static ssize_t realview_get_build(struct device *dev,
+			       struct device_attribute *attr,
+			       char *buf)
+{
+	return sprintf(buf, "%02x\n", (realview_coreid & 0xFF));
+}
+
+static struct device_attribute realview_build_attr =
+	__ATTR(build,  S_IRUGO, realview_get_build,  NULL);
+
+static int realview_soc_probe(struct platform_device *pdev)
+{
+	static struct regmap *syscon_regmap;
+	struct soc_device *soc_dev;
+	struct soc_device_attribute *soc_dev_attr;
+	struct device_node *np = pdev->dev.of_node;
+	int ret;
+
+	syscon_regmap = syscon_regmap_lookup_by_phandle(np, "regmap");
+	if (IS_ERR(syscon_regmap))
+		return PTR_ERR(syscon_regmap);
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		return -ENOMEM;
+
+	ret = of_property_read_string(np, "compatible",
+				      &soc_dev_attr->soc_id);
+	if (ret)
+		return -EINVAL;
+
+	soc_dev_attr->machine = "RealView";
+	soc_dev_attr->family = "Versatile";
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev)) {
+		kfree(soc_dev_attr);
+		return -ENODEV;
+	}
+	ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET,
+			  &realview_coreid);
+	if (ret)
+		return -ENODEV;
+
+	device_create_file(soc_device_to_device(soc_dev), &realview_manf_attr);
+	device_create_file(soc_device_to_device(soc_dev), &realview_board_attr);
+	device_create_file(soc_device_to_device(soc_dev), &realview_arch_attr);
+	device_create_file(soc_device_to_device(soc_dev), &realview_build_attr);
+
+	dev_info(&pdev->dev, "RealView Syscon Core ID: 0x%08x\n",
+		 realview_coreid);
+	/* FIXME: add attributes for SoC to sysfs */
+	return 0;
+}
+
+static struct platform_driver realview_soc_driver = {
+	.probe = realview_soc_probe,
+	.driver = {
+		.name = "realview-soc",
+		.of_match_table = realview_soc_of_match,
+	},
+};
+module_platform_driver(realview_soc_driver);
-- 
1.9.3

[PATCH 5/8] ARM: l2x0: move DT parsing for cache props

[Linus Walleij]

The current diagnostic prints in the l2x0 driver will print
warnings like this if the AUX register i modified by the
mask and set words passed to the l2x0_init() function:

L2C: platform modifies aux control register: 0x02020fff -> 0x02730fff
L2C: DT/platform modifies aux control register: 0x02020fff -> 0x02730fff
L2C-220 cache controller enabled, 8 ways, 128 kB
L2C-220: CACHE_ID 0x41000486, AUX_CTRL 0x06730fff

However this is not printed properly if the DT modifies
the AUX register, even if the debug print says so. As the
call to ->of_parse for the cache variant is placed after this
print.

Move the ->of_parse call above the print so we get proper
diagnostics.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 arch/arm/mm/cache-l2x0.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 5f2c988a06ac..363c27bee3f6 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -1518,6 +1518,11 @@ int __init l2x0_of_init(u32 aux_val, u32 aux_mask)
 	    of_property_read_bool(np, "arm,io-coherent"))
 		data = &of_l2c310_coherent_data;
 
+	/* L2 configuration can only be changed if the cache is disabled */
+	if (!(readl_relaxed(l2x0_base + L2X0_CTRL) & L2X0_CTRL_EN))
+		if (data->of_parse)
+			data->of_parse(np, &aux_val, &aux_mask);
+
 	old_aux = readl_relaxed(l2x0_base + L2X0_AUX_CTRL);
 	if (old_aux != ((old_aux & aux_mask) | aux_val)) {
 		pr_warn("L2C: platform modifies aux control register: 0x%08x -> 0x%08x\n",
@@ -1530,11 +1535,6 @@ int __init l2x0_of_init(u32 aux_val, u32 aux_mask)
 	if (!of_property_read_bool(np, "cache-unified"))
 		pr_err("L2C: device tree omits to specify unified cache\n");
 
-	/* L2 configuration can only be changed if the cache is disabled */
-	if (!(readl_relaxed(l2x0_base + L2X0_CTRL) & L2X0_CTRL_EN))
-		if (data->of_parse)
-			data->of_parse(np, &aux_val, &aux_mask);
-
 	if (cache_id_part_number_from_dt)
 		cache_id = cache_id_part_number_from_dt;
 	else
-- 
1.9.3

[PATCH 6/8] ARM: l2c: parse 'cache-size' and 'cache-sets' properties

[Linus Walleij]

From: Florian Fainelli <f.fainelli@gmail.com>

When both 'cache-size' and 'cache-sets' are specified for a L2 cache
controller node, parse those properties and make sure we validate the
way_size based on which type of L2 cache controller we are using.

Update the L2 cache controller Device Tree binding with the optional
'cache-size' and 'cache-sets' properties.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 Documentation/devicetree/bindings/arm/l2cc.txt |  2 +
 arch/arm/mm/cache-l2x0.c                       | 61 ++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt
index af527ee111c2..d33ed2344c7e 100644
--- a/Documentation/devicetree/bindings/arm/l2cc.txt
+++ b/Documentation/devicetree/bindings/arm/l2cc.txt
@@ -44,6 +44,8 @@ Optional properties:
   I/O coherent mode. Valid only when the arm,pl310-cache compatible
   string is used.
 - interrupts : 1 combined interrupt.
+- cache-size : specifies the size in bytes of the cache
+- cache-sets : specifies the number of associativity sets of the cache
 - cache-id-part: cache id part number to be used if it is not present
   on hardware
 - wt-override: If present then L2 is forced to Write through mode
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 363c27bee3f6..c735f792c3d5 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -945,6 +945,61 @@ static int l2_wt_override;
  * pass it though the device tree */
 static u32 cache_id_part_number_from_dt;
 
+static void __init l2x0_cache_size_of_parse(const struct device_node *np,
+					    u32 *aux_val, u32 *aux_mask,
+					    u32 max_way_size)
+{
+	u32 mask = 0, val = 0;
+	u32 size = 0, sets = 0;
+	u32 way_size = 0, way_size_bits = 1;
+
+	of_property_read_u32(np, "cache-size", &size);
+	of_property_read_u32(np, "cache-sets", &sets);
+
+	if (!size || !sets)
+		return;
+
+	way_size = size / sets;
+
+	if (way_size > max_way_size) {
+		pr_warn("L2C: way size %dKB is too large\n", way_size >> 10);
+		return;
+	}
+
+	way_size >>= 10;
+	switch (way_size) {
+	case 512:
+		way_size_bits = 6;
+		break;
+	case 256:
+		way_size_bits = 5;
+		break;
+	case 128:
+		way_size_bits = 4;
+		break;
+	case 64:
+		way_size_bits = 3;
+		break;
+	case 32:
+		way_size_bits = 2;
+		break;
+	case 16:
+		way_size_bits = 1;
+		break;
+	default:
+		pr_err("cache way size: %d KB is not mapped\n",
+		       way_size);
+		break;
+	}
+
+	mask |= L2C_AUX_CTRL_WAY_SIZE_MASK;
+	val |= (way_size_bits << L2C_AUX_CTRL_WAY_SIZE_SHIFT);
+
+	*aux_val &= ~mask;
+	*aux_val |= val;
+	*aux_mask &= ~mask;
+}
+
 static void __init l2x0_of_parse(const struct device_node *np,
 				 u32 *aux_val, u32 *aux_mask)
 {
@@ -974,6 +1029,8 @@ static void __init l2x0_of_parse(const struct device_node *np,
 		val |= (dirty - 1) << L2X0_AUX_CTRL_DIRTY_LATENCY_SHIFT;
 	}
 
+	l2x0_cache_size_of_parse(np, aux_val, aux_mask, SZ_256K);
+
 	*aux_val &= ~mask;
 	*aux_val |= val;
 	*aux_mask &= ~mask;
@@ -1047,6 +1104,8 @@ static void __init l2c310_of_parse(const struct device_node *np,
 		writel_relaxed((filter[0] & ~(SZ_1M - 1)) | L310_ADDR_FILTER_EN,
 			       l2x0_base + L310_ADDR_FILTER_START);
 	}
+
+	l2x0_cache_size_of_parse(np, aux_val, aux_mask, SZ_512K);
 }
 
 static const struct l2c_init_data of_l2c310_data __initconst = {
@@ -1253,6 +1312,8 @@ static void __init aurora_of_parse(const struct device_node *np,
 	*aux_val &= ~mask;
 	*aux_val |= val;
 	*aux_mask &= ~mask;
+
+	l2x0_cache_size_of_parse(np, aux_val, aux_mask, SZ_256K);
 }
 
 static const struct l2c_init_data of_aurora_with_outer_data __initconst = {
-- 
1.9.3

[PATCH 7/8] ARM: l2x0: support associativity from DT

[Linus Walleij]

The ARM RealView platforms comes with boot loaders that fail
to set up cache size, ways and associativity correctly. This
complements Florian's patch to set up cache size and sets from
the device tree with the possibility to set up associativity
on the L2C-220 cache variant.

Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 Documentation/devicetree/bindings/arm/l2cc.txt |  1 +
 arch/arm/mm/cache-l2x0.c                       | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt
index d33ed2344c7e..94b02f704f1d 100644
--- a/Documentation/devicetree/bindings/arm/l2cc.txt
+++ b/Documentation/devicetree/bindings/arm/l2cc.txt
@@ -44,6 +44,7 @@ Optional properties:
   I/O coherent mode. Valid only when the arm,pl310-cache compatible
   string is used.
 - interrupts : 1 combined interrupt.
+- cache-associativity : specifies the associativity of the cache
 - cache-size : specifies the size in bytes of the cache
 - cache-sets : specifies the number of associativity sets of the cache
 - cache-id-part: cache id part number to be used if it is not present
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index c735f792c3d5..ebed9638b96c 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -1007,6 +1007,7 @@ static void __init l2x0_of_parse(const struct device_node *np,
 	u32 tag = 0;
 	u32 dirty = 0;
 	u32 val = 0, mask = 0;
+	u32 assoc = 0;
 
 	of_property_read_u32(np, "arm,tag-latency", &tag);
 	if (tag) {
@@ -1029,6 +1030,16 @@ static void __init l2x0_of_parse(const struct device_node *np,
 		val |= (dirty - 1) << L2X0_AUX_CTRL_DIRTY_LATENCY_SHIFT;
 	}
 
+	of_property_read_u32(np, "cache-associativity", &assoc);
+	if (assoc) {
+		if (assoc > 8) {
+			pr_warn("L2C: associativity %d is too large\n", assoc);
+		} else {
+			mask |= L2X0_AUX_CTRL_ASSOC_MASK;
+			val |= (assoc << L2X0_AUX_CTRL_ASSOC_SHIFT);
+		}
+	}
+
 	l2x0_cache_size_of_parse(np, aux_val, aux_mask, SZ_256K);
 
 	*aux_val &= ~mask;
-- 
1.9.3

[PATCH 8/8 v5] ARM: realview: basic device tree implementation

[Linus Walleij]

This implements basic device tree boot support for the RealView
platforms, with a basic device tree for ARM PB1176 as an example.

The implementation is done with a new DT-specific board file
using only pre-existing bindings for the basic IRQ, timer and
serial port drivers. A new compatible type is added to the GIC
for the ARM1176.

This implementation uses the MFD syscon handle from day one to
access the system controller registers, and register the devices
using the SoC bus.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh@kernel.org>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v4->v5:
- Move the l2x0_init() aux set-ups over to the device tree,
  using one patch from Florian Fainelli and one patch from
  myself to support the needed bits.
- Put "simple-bus" last in binding documentation, examples
  and device tree so we go from most to least specific.
- Use the compatible arm11mp-gic binding for the GIC, and add
  a more specific binding "arm,arm1176jzf-devchip-gic" for the
  variant specifically found on the ARM1176JZF development
  chip. Add IRQCHIP_DECLARE() for both variants.
- Drop the "reboot device" node as we rewrote the driver to
  hog onto the syscon node directly.
- Augment device tree for the new register-bit-leds used with
  the syscon.
ChangeLog v3->v4:
- Switch the LEDs to usa a new syscon-LEDs driver so we can
  use the syscon as a hub for all these registers
- Split out the SoC driver to its own file in drivers/soc
ChangeLog v2->v3:
- Rename uart at 0x12345678 to serial at 0x12345678 in DTS file
- Drop static remapping for the LEDs, using my new invention
  syscon-leds instead
- Drop the hunk selecting ARM_DMA_MEM_BUFFERABLE for the DT
  version of the RealView platform. We think this is a local
  optimization we can live without.
- Split off the reset driver to a separate syscon-based reset
  driver in drivers/power/reset, add separate device tree
  bindings for this driver.
- To make sure the reset driver is always available for this
  system a few extra select statements are needed in Kconfig
- Split off the SoC bus driver to an easily identifiable chunk
  inside the mach-realview/realview-dt.c file. This *can* be
  spun off as a separate driver under drivers/soc for example
  but we need some separate discussion on this subject.
- Augment the SoC driver to display some system info so it's
  clear why this driver is there.
- Drop surplus string "with device tree" from machine
  description in the DTS file.
- Move the new GIC compatible string in alphabetic order.
ChangeLog v1->v2:
- Adjust timer clock names to be the same as the example in the
  device tree binding.
- Remove all memory fixup code - this should be handled by the
  device tree specification of memory areas or by special MM hacks
  for the RealView PBX.
- Fix the documentation around syscon to specify that it can be in
  any node, need not be the root node.
- Switch device tree license to the BSD license, taken from
  arch/powerpc/boot/dts/p1024rdb_32b.dts
- Add a hunk for the new compatible string to
  Documentation/devicetree/bindings/arm/gic.txt
- Move the clocks out of the SoC node, certainly the xtal is not
  sitting on the SoC...
- Sort the selects in Kconfig alphabetically
- Use IS_ENABLED() for the l2x0 code snippet
- Instead of checking the board variant in the reset routine to
  figure out how to tweak the reset controller, have a compatible
  string for each syscon variant, map it to an enum that provides a
  unique type ID and that way figure out how to handle it in a maybe
  more elegant way.
- Open issue: what do to with the l2x0 stuff?
---
 Documentation/devicetree/bindings/arm/arm-boards |  65 ++++++
 Documentation/devicetree/bindings/arm/gic.txt    |   1 +
 arch/arm/boot/dts/Makefile                       |   1 +
 arch/arm/boot/dts/arm-realview-pb1176.dts        | 246 +++++++++++++++++++++++
 arch/arm/mach-realview/Kconfig                   |  13 ++
 arch/arm/mach-realview/Makefile                  |   1 +
 arch/arm/mach-realview/realview-dt.c             |  47 +++++
 drivers/irqchip/irq-gic.c                        |   2 +
 8 files changed, 376 insertions(+)
 create mode 100644 arch/arm/boot/dts/arm-realview-pb1176.dts
 create mode 100644 arch/arm/mach-realview/realview-dt.c

diff --git a/Documentation/devicetree/bindings/arm/arm-boards b/Documentation/devicetree/bindings/arm/arm-boards
index c554ed3d44fb..556c8665fdbf 100644
--- a/Documentation/devicetree/bindings/arm/arm-boards
+++ b/Documentation/devicetree/bindings/arm/arm-boards
@@ -92,3 +92,68 @@ Required nodes:
 - core-module: the root node to the Versatile platforms must have
   a core-module with regs and the compatible strings
   "arm,core-module-versatile", "syscon"
+
+ARM RealView Boards
+-------------------
+The RealView boards cover tailored evaluation boards that are used to explore
+the ARM11 and Cortex A-8 and Cortex A-9 processors.
+
+Required properties (in root node):
+	/* RealView Emulation Baseboard */
+	compatible = "arm,realview-eb";
+	 /* RealView Platform Baseboard for ARM1176JZF-S */
+	compatible = "arm,realview-pb1176";
+	/* RealView Platform Baseboard for ARM11 MPCore */
+	compatible = "arm,realview-pb11mp";
+	/* RealView Platform Baseboard for Cortex A-8 */
+	compatible = "arm,realview-pba8";
+	/* RealView Platform Baseboard Explore for Cortex A-9 */
+	compatible = "arm,realview-pbx";
+
+Required nodes:
+
+- soc: some node of the RealView platforms must be the SoC
+  node that contain the SoC-specific devices, withe the compatible
+  string set to one of these tuples:
+   "arm,realview-eb-soc", "simple-bus"
+   "arm,realview-pb1176-soc", "simple-bus"
+   "arm,realview-pb11mp-soc", "simple-bus"
+   "arm,realview-pba8-soc", "simple-bus"
+   "arm,realview-pbx-soc", "simple-bus"
+
+- syscon: some subnode of the RealView SoC node must be a
+  system controller node pointing to the control registers,
+  with the compatible string set to one of these tuples:
+   "arm,realview-eb-syscon", "syscon"
+   "arm,realview-pb1176-syscon", "syscon"
+   "arm,realview-pb11mp-syscon", "syscon"
+   "arm,realview-pba8-syscon", "syscon"
+   "arm,realview-pbx-syscon", "syscon"
+
+  Required properties for the system controller:
+  - regs: the location and size of the system controller registers,
+    one range of 0x1000 bytes.
+
+Example:
+
+/dts-v1/;
+#include <dt-bindings/interrupt-controller/irq.h>
+#include "skeleton.dtsi"
+
+/ {
+	model = "ARM RealView PB1176 with device tree";
+	compatible = "arm,realview-pb1176";
+
+	soc {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "arm,realview-pb1176-soc", "simple-bus";
+		ranges;
+
+		syscon: syscon at 10000000 {
+			compatible = "arm,realview-syscon", "syscon";
+			reg = <0x10000000 0x1000>;
+		};
+
+	};
+};
diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
index c7d2fa156678..b38608af66db 100644
--- a/Documentation/devicetree/bindings/arm/gic.txt
+++ b/Documentation/devicetree/bindings/arm/gic.txt
@@ -17,6 +17,7 @@ Main node required properties:
 	"arm,cortex-a7-gic"
 	"arm,arm11mp-gic"
 	"brcm,brahma-b15-gic"
+	"arm,arm1176jzf-devchip-gic"
 - interrupt-controller : Identifies the node as an interrupt controller
 - #interrupt-cells : Specifies the number of cells needed to encode an
   interrupt source.  The type shall be a <u32> and the value shall be 3.
diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index b8c5cd3ddeb9..e55d28eed151 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -344,6 +344,7 @@ dtb-$(CONFIG_ARCH_QCOM) += \
 	qcom-apq8084-mtp.dtb \
 	qcom-msm8660-surf.dtb \
 	qcom-msm8960-cdp.dtb
+dtb-$(CONFIG_ARCH_REALVIEW) += arm-realview-pb1176.dtb
 dtb-$(CONFIG_ARCH_ROCKCHIP) += \
 	rk3066a-bqcurie2.dtb \
 	rk3188-radxarock.dtb \
diff --git a/arch/arm/boot/dts/arm-realview-pb1176.dts b/arch/arm/boot/dts/arm-realview-pb1176.dts
new file mode 100644
index 000000000000..04d4d64e2ada
--- /dev/null
+++ b/arch/arm/boot/dts/arm-realview-pb1176.dts
@@ -0,0 +1,246 @@
+/*
+ * Copyright 2014 Linaro Ltd
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/dts-v1/;
+#include <dt-bindings/interrupt-controller/irq.h>
+#include "skeleton.dtsi"
+
+/ {
+	model = "ARM RealView PB1176";
+	compatible = "arm,realview-pb1176";
+
+	chosen { };
+
+	aliases {
+		serial0 = &pb1176_serial0;
+		serial1 = &pb1176_serial1;
+		serial2 = &pb1176_serial2;
+		serial3 = &pb1176_serial3;
+	};
+
+	memory {
+		/* 128 MiB memory @ 0x0 */
+		reg = <0x00000000 0x08000000>;
+	};
+
+	xtal24mhz: xtal24mhz at 24M {
+		#clock-cells = <0>;
+		compatible = "fixed-clock";
+		clock-frequency = <24000000>;
+	};
+
+	timclk: timclk at 1M {
+		#clock-cells = <0>;
+		compatible = "fixed-factor-clock";
+		clock-div = <24>;
+		clock-mult = <1>;
+		clocks = <&xtal24mhz>;
+	};
+
+	uartclk: uartclk at 24M {
+		#clock-cells = <0>;
+		compatible = "fixed-factor-clock";
+		clock-div = <1>;
+		clock-mult = <1>;
+		clocks = <&xtal24mhz>;
+	};
+
+	/* FIXME: this actually hangs off the PLL clocks */
+	pclk: pclk at 0 {
+		#clock-cells = <0>;
+		compatible = "fixed-clock";
+		clock-frequency = <0>;
+	};
+
+	soc {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "arm,realview-pb1176-soc", "simple-bus";
+		regmap = <&syscon>;
+		ranges;
+
+		syscon: syscon at 10000000 {
+			compatible = "arm,realview-pb1176-syscon", "syscon";
+			reg = <0x10000000 0x1000>;
+
+			led at 08.0 {
+				compatible = "register-bit-led";
+				offset = <0x08>;
+				mask = <0x01>;
+				label = "versatile:0";
+				linux,default-trigger = "heartbeat";
+				default-state = "on";
+			};
+			led at 08.1 {
+				compatible = "register-bit-led";
+				offset = <0x08>;
+				mask = <0x02>;
+				label = "versatile:1";
+				linux,default-trigger = "mmc0";
+				default-state = "off";
+			};
+			led at 08.2 {
+				compatible = "register-bit-led";
+				offset = <0x08>;
+				mask = <0x04>;
+				label = "versatile:2";
+				linux,default-trigger = "cpu0";
+				default-state = "off";
+			};
+			led at 08.3 {
+				compatible = "register-bit-led";
+				offset = <0x08>;
+				mask = <0x08>;
+				label = "versatile:3";
+				default-state = "off";
+			};
+			led at 08.4 {
+				compatible = "register-bit-led";
+				offset = <0x08>;
+				mask = <0x10>;
+				label = "versatile:4";
+				default-state = "off";
+			};
+			led at 08.5 {
+				compatible = "register-bit-led";
+				offset = <0x08>;
+				mask = <0x20>;
+				label = "versatile:5";
+				default-state = "off";
+			};
+			led at 08.6 {
+				compatible = "register-bit-led";
+				offset = <0x08>;
+				mask = <0x40>;
+				label = "versatile:6";
+				default-state = "off";
+			};
+			led at 08.7 {
+				compatible = "register-bit-led";
+				offset = <0x08>;
+				mask = <0x80>;
+				label = "versatile:7";
+				default-state = "off";
+			};
+		};
+
+		/* Primary DevChip GIC synthesized with the CPU */
+		intc_dc1176: interrupt-controller at 10120000 {
+			compatible = "arm,arm1176jzf-devchip-gic", "arm,arm11mp-gic";
+			#interrupt-cells = <3>;
+			#address-cells = <1>;
+			interrupt-controller;
+			reg = <0x10121000 0x1000>,
+			      <0x10120000 0x100>;
+		};
+
+		/* This GIC on the board is cascaded off the DevChip GIC */
+		intc_pb1176: interrupt-controller at 10040000 {
+			compatible = "arm,arm1176jzf-devchip-gic", "arm,arm11mp-gic";
+			#interrupt-cells = <3>;
+			#address-cells = <1>;
+			interrupt-controller;
+			reg = <0x10041000 0x1000>,
+			      <0x10040000 0x100>;
+			interrupt-parent = <&intc_dc1176>;
+			interrupts = <0 31 IRQ_TYPE_LEVEL_HIGH>;
+		};
+
+		L2: l2-cache {
+			compatible = "arm,l220-cache";
+			reg = <0x10110000 0x1000>;
+			interrupt-parent = <&intc_dc1176>;
+			interrupts = <0 13 IRQ_TYPE_LEVEL_HIGH>;
+			cache-unified;
+			cache-level = <2>;
+			/*
+			 * Override default cache size, sets and
+			 * associativity as these may be erroneously set
+			 * up by boot loader(s).
+			 */
+			cache-size = <131072>; // 128kB
+			cache-sets = <8>;
+			cache-associativity = <8>;
+		};
+
+		pmu {
+			compatible = "arm,arm1176-pmu";
+			interrupt-parent = <&intc_dc1176>;
+			interrupts = <0 7 IRQ_TYPE_LEVEL_HIGH>;
+		};
+
+		timer01: timer at 10104000 {
+			compatible = "arm,sp804", "arm,primecell";
+			reg = <0x10104000 0x1000>;
+			interrupt-parent = <&intc_dc1176>;
+			interrupts = <0 8 IRQ_TYPE_LEVEL_HIGH>, <0 9 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&timclk>, <&timclk>, <&pclk>;
+			clock-names = "timer1", "timer2", "apb_pclk";
+		};
+
+		timer23: timer at 10105000 {
+			compatible = "arm,sp804", "arm,primecell";
+			reg = <0x10105000 0x1000>;
+			interrupt-parent = <&intc_dc1176>;
+			interrupts = <0 10 IRQ_TYPE_LEVEL_HIGH>;
+			arm,sp804-has-irq = <1>;
+			clocks = <&timclk>, <&timclk>, <&pclk>;
+			clock-names = "timer1", "timer2", "apb_pclk";
+		};
+
+		pb1176_serial0: serial at 1010c000 {
+			compatible = "arm,pl011", "arm,primecell";
+			reg = <0x1010c000 0x1000>;
+			interrupt-parent = <&intc_dc1176>;
+			interrupts = <0 18 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&uartclk>, <&pclk>;
+			clock-names = "uartclk", "apb_pclk";
+		};
+
+		pb1176_serial1: serial at 1010d000 {
+			compatible = "arm,pl011", "arm,primecell";
+			reg = <0x1010d000 0x1000>;
+			interrupt-parent = <&intc_dc1176>;
+			interrupts = <0 19 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&uartclk>, <&pclk>;
+			clock-names = "uartclk", "apb_pclk";
+		};
+
+		pb1176_serial2: serial at 1010e000 {
+			compatible = "arm,pl011", "arm,primecell";
+			reg = <0x1010e000 0x1000>;
+			interrupt-parent = <&intc_dc1176>;
+			interrupts = <0 20 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&uartclk>, <&pclk>;
+			clock-names = "uartclk", "apb_pclk";
+		};
+
+		pb1176_serial3: serial at 1010f000 {
+			compatible = "arm,pl011", "arm,primecell";
+			reg = <0x1010f000 0x1000>;
+			interrupt-parent = <&intc_dc1176>;
+			interrupts = <0 21 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&uartclk>, <&pclk>;
+			clock-names = "uartclk", "apb_pclk";
+		};
+	};
+};
diff --git a/arch/arm/mach-realview/Kconfig b/arch/arm/mach-realview/Kconfig
index 9db2029aa632..565925f37dc5 100644
--- a/arch/arm/mach-realview/Kconfig
+++ b/arch/arm/mach-realview/Kconfig
@@ -1,6 +1,19 @@
 menu "RealView platform type"
 	depends on ARCH_REALVIEW
 
+config REALVIEW_DT
+	bool "Support RealView(R) Device Tree based boot"
+	select ARM_GIC
+	select MFD_SYSCON
+	select POWER_RESET
+	select POWER_RESET_VERSATILE
+	select POWER_SUPPLY
+	select SOC_REALVIEW
+	select USE_OF
+	help
+	  Include support for booting the ARM(R) RealView(R) evaluation
+	  boards using a device tree machine description.
+
 config MACH_REALVIEW_EB
 	bool "Support RealView(R) Emulation Baseboard"
 	select ARM_GIC
diff --git a/arch/arm/mach-realview/Makefile b/arch/arm/mach-realview/Makefile
index 541fa4c109ef..e07fdf7ae8a7 100644
--- a/arch/arm/mach-realview/Makefile
+++ b/arch/arm/mach-realview/Makefile
@@ -3,6 +3,7 @@
 #
 
 obj-y					:= core.o
+obj-$(CONFIG_REALVIEW_DT)		+= realview-dt.o
 obj-$(CONFIG_MACH_REALVIEW_EB)		+= realview_eb.o
 obj-$(CONFIG_MACH_REALVIEW_PB11MP)	+= realview_pb11mp.o
 obj-$(CONFIG_MACH_REALVIEW_PB1176)	+= realview_pb1176.o
diff --git a/arch/arm/mach-realview/realview-dt.c b/arch/arm/mach-realview/realview-dt.c
new file mode 100644
index 000000000000..fb85a32e2709
--- /dev/null
+++ b/arch/arm/mach-realview/realview-dt.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2014 Linaro Ltd.
+ *
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/of_platform.h>
+#include <asm/mach/arch.h>
+#include <asm/hardware/cache-l2x0.h>
+#include "core.h"
+
+static void __init realview_dt_init_machine(void)
+{
+	int ret;
+
+#if IS_ENABLED(CONFIG_CACHE_L2X0)
+	l2x0_of_init(0, ~0);
+#endif
+
+	ret = of_platform_populate(NULL, of_default_bus_match_table,
+				   NULL, NULL);
+	if (ret) {
+		pr_crit("could not populate device tree\n");
+		return;
+	}
+}
+
+static const char *realview_dt_platform_compat[] __initconst = {
+	"arm,realview-eb",
+	"arm,realview-pb1176",
+	"arm,realview-pb11mp",
+	"arm,realview-pba8",
+	"arm,realview-pbx",
+	NULL,
+};
+
+DT_MACHINE_START(REALVIEW_DT, "ARM RealView Machine (Device Tree Support)")
+	.init_machine	= realview_dt_init_machine,
+#ifdef CONFIG_ZONE_DMA
+	.dma_zone_size	= SZ_256M,
+#endif
+	.dt_compat	= realview_dt_platform_compat,
+MACHINE_END
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 4b959e606fe8..4e75e3f24a97 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -1022,6 +1022,8 @@ gic_of_init(struct device_node *node, struct device_node *parent)
 	return 0;
 }
 IRQCHIP_DECLARE(gic_400, "arm,gic-400", gic_of_init);
+IRQCHIP_DECLARE(arm11mp_gic, "arm,arm11mp-gic", gic_of_init);
+IRQCHIP_DECLARE(arm1176jzf_dc_gic, "arm,arm1176jzf-devchip-gic", gic_of_init);
 IRQCHIP_DECLARE(cortex_a15_gic, "arm,cortex-a15-gic", gic_of_init);
 IRQCHIP_DECLARE(cortex_a9_gic, "arm,cortex-a9-gic", gic_of_init);
 IRQCHIP_DECLARE(cortex_a7_gic, "arm,cortex-a7-gic", gic_of_init);
-- 
1.9.3

[PATCH 2/8 v2] leds: add device tree bindings for register bit LEDs

[Arnd Bergmann]

On Tuesday 02 September 2014 14:02:28 Linus Walleij wrote:
> +LED sub-node properties:
> +
> +Required properties:
> +- compatible : must be "register-bit-led"
> +- offset : register offset to the register controlling this LED
> +- mask : bit mask for the bit controlling this LED in the register
> +  typically 0x01, 0x02, 0x04 ...
> 

How does the driver know whether to do byte or word sized accesses?

	Arnd

[PATCH 3/8 v2] power: reset: driver for the Versatile syscon reboot

[Arnd Bergmann]

On Tuesday 02 September 2014 14:02:29 Linus Walleij wrote:
> +enum versatile_reboot {
> +       REALVIEW_REBOOT_EB,
> +       REALVIEW_REBOOT_PB1176,
> +       REALVIEW_REBOOT_PB11MP,
> +       REALVIEW_REBOOT_PBA8,
> +       REALVIEW_REBOOT_PBX,
> +};
> +static const struct of_device_id versatile_reboot_of_match[] = {
> +       {
> +               .compatible = "arm,realview-eb-syscon",
> +               .data = (void *)REALVIEW_REBOOT_EB,
> +       },
...
> +};
> +
> +static void versatile_reboot(enum reboot_mode mode, const char *cmd)
> +{
> +       /* Unlock the reset register */
> +       regmap_write(syscon_regmap, REALVIEW_SYS_LOCK_OFFSET,
> +                    REALVIEW_SYS_LOCK_VAL);
> +       /* Then hit reset on the different machines */
> +       switch (versatile_reboot_type) {
> +       case REALVIEW_REBOOT_EB:
> +               regmap_write(syscon_regmap,
> +                            REALVIEW_SYS_RESETCTL_OFFSET, 0x0008);
> +               break;
> ...
> +       }
> +       dsb();

Looks ok to me. Just an idea for further simplification, we could easily encode
the writes into the .data field:

	{
		.compatible = "arm,realview-eb-syscon",
		.data = (void *)0x00080000,
	},
	...
	{
               .compatible = "arm,realview-pbx-syscon",
               .data = (void *)0x00f000f4,
        },


static void versatile_reboot(enum reboot_mode mode, const char *cmd)
{

	/* Unlock the reset register */
	regmap_write(syscon_regmap, REALVIEW_SYS_LOCK_OFFSET,
		     REALVIEW_SYS_LOCK_VAL);

	regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
					versatile_reboot_type >> 16);

	if (versatile_reboot_type & 0xffff)
		regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
			     versatile_reboot_type >> 16);

	dsb();
}

It's definitely shorter, you can decide if you like it better or not,
and add my 'Acked-by: Arnd Bergmann <arnd@arndb.de>' whichever you choose.

	Arnd

[PATCH 8/8 v5] ARM: realview: basic device tree implementation

[Arnd Bergmann]

On Tuesday 02 September 2014 14:02:34 Linus Walleij wrote:
> +static void __init realview_dt_init_machine(void)
> +{
> +       int ret;
> +
> +#if IS_ENABLED(CONFIG_CACHE_L2X0)
> +       l2x0_of_init(0, ~0);
> +#endif
> +
> +       ret = of_platform_populate(NULL, of_default_bus_match_table,
> +                                  NULL, NULL);
> +       if (ret) {
> +               pr_crit("could not populate device tree\n");
> +               return;
> +       }
> +}
> +
> +static const char *realview_dt_platform_compat[] __initconst = {
> +       "arm,realview-eb",
> +       "arm,realview-pb1176",
> +       "arm,realview-pb11mp",
> +       "arm,realview-pba8",
> +       "arm,realview-pbx",
> +       NULL,
> +};
> +
> +DT_MACHINE_START(REALVIEW_DT, "ARM RealView Machine (Device Tree Support)")
> +       .init_machine   = realview_dt_init_machine,
> +#ifdef CONFIG_ZONE_DMA
> +       .dma_zone_size  = SZ_256M,
> +#endif
> +       .dt_compat      = realview_dt_platform_compat,
> +MACHINE_END
> 

This looks almost perfect to me, but there is one simplification you
can do now:

If you add the .l2c_aux_val/.l2c_aux_mask fields to the
machine descriptor, you can remove the rest of the
realview_dt_init_machine function, and have only the
dma_zone_size setting left here.

On a related note, I think we need to add the same setting to the
default machine descriptor in setup_machine_fdt() so it gets set
up correctly there too.

	Arnd

[PATCH 5/8] ARM: l2x0: move DT parsing for cache props

[Russell King - ARM Linux]

On Tue, Sep 02, 2014 at 02:02:31PM +0200, Linus Walleij wrote:
> The current diagnostic prints in the l2x0 driver will print
> warnings like this if the AUX register i modified by the
> mask and set words passed to the l2x0_init() function:
> 
> L2C: platform modifies aux control register: 0x02020fff -> 0x02730fff
> L2C: DT/platform modifies aux control register: 0x02020fff -> 0x02730fff

Notice that there are two here.

The first means that the platform passed values which resulted in an
actual modification to the control register.  This happens in
l2x0_of_init() to identify values of aux_mask/aux_val which result
in manipulation of the control register by hard-coded platform values.

The second means that the platform _or_ the DT resulted in an actual
modification of the control register.  This happens in __l2c_init(),
after the DT has been parsed, or after the non-DT code paths to identify
any remaining modifications.

I don't see any point to this patch.

-- 
FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up
according to speedtest.net.

[PATCH 7/8] ARM: l2x0: support associativity from DT

[Russell King - ARM Linux]

On Tue, Sep 02, 2014 at 02:02:33PM +0200, Linus Walleij wrote:
> The ARM RealView platforms comes with boot loaders that fail
> to set up cache size, ways and associativity correctly. This
> complements Florian's patch to set up cache size and sets from
> the device tree with the possibility to set up associativity
> on the L2C-220 cache variant.

Do we need this?

If we have the cache size, the number of sets, and the cache block size
(cache line size) which are all ePAPR specified properties for a cache,
then:

	number of cache blocks = cache size / cache block size
	ways of associativity = number of cache blocks / number of sets
	way size = cache block size * number of sets

It's a tad annoying to have to convert between the two representations,
but ePAPR decided on size, sets and block size rather than size and
ways.

See arch/powerpc/kernel/cacheinfo.c line 260 for the powerpc
associativity calculations from these values.

-- 
FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up
according to speedtest.net.

[PATCH 2/8 v2] leds: add device tree bindings for register bit LEDs

[Geert Uytterhoeven]

Hi Linus,

On Tue, Sep 2, 2014 at 2:02 PM, Linus Walleij <linus.walleij@linaro.org> wrote:
> +LED sub-node properties:
> +
> +Required properties:
> +- compatible : must be "register-bit-led"
> +- offset : register offset to the register controlling this LED
> +- mask : bit mask for the bit controlling this LED in the register

Why don't you use a "reg" property with "#address-cells = <2>" and
"#size-cells = <1>", so you can store offset and mask there?

> +syscon: syscon at 10000000 {
> +       compatible = "arm,realview-pb1176-syscon", "syscon";
> +       reg = <0x10000000 0x1000>;
> +
> +       led at 08.0 {
> +               compatible = "register-bit-led";
> +               offset = <0x08>;
> +               mask = <0x01>;
> +               label = "versatile:0";
> +               linux,default-trigger = "heartbeat";
> +               default-state = "on";
> +       };

ePAPR v1.1 says:

"The unit-address must match the first address specified in the reg property
 of the node. If the node has no reg property, the @ and unit-address must
 be omitted ..."

So you cannot have the "@8.0" without a "reg" property.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

[PATCH 5/8] ARM: l2x0: move DT parsing for cache props

[Linus Walleij]

On Tue, Sep 2, 2014 at 2:43 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:

> I don't see any point to this patch.

Neither do I after looking closer. Hm. I must have been confusing
myself, I'm dropping this crap.

Yours,
Linus Walleij

[PATCH 2/8 v2] leds: add device tree bindings for register bit LEDs

[Linus Walleij]

On Tue, Sep 2, 2014 at 4:22 PM, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> On Tue, Sep 2, 2014 at 2:02 PM, Linus Walleij <linus.walleij@linaro.org> wrote:
>> +LED sub-node properties:
>> +
>> +Required properties:
>> +- compatible : must be "register-bit-led"
>> +- offset : register offset to the register controlling this LED
>> +- mask : bit mask for the bit controlling this LED in the register
>
> Why don't you use a "reg" property with "#address-cells = <2>" and
> "#size-cells = <1>", so you can store offset and mask there?

Because "reg" means a register range not based off another range,
i.e. not relative, and the OF cores does not allow overlapping
reg ranges as would be the case here IIRC.

>> +syscon: syscon at 10000000 {
>> +       compatible = "arm,realview-pb1176-syscon", "syscon";
>> +       reg = <0x10000000 0x1000>;
>> +
>> +       led at 08.0 {
>> +               compatible = "register-bit-led";
>> +               offset = <0x08>;
>> +               mask = <0x01>;
>> +               label = "versatile:0";
>> +               linux,default-trigger = "heartbeat";
>> +               default-state = "on";
>> +       };
>
> ePAPR v1.1 says:
>
> "The unit-address must match the first address specified in the reg property
>  of the node. If the node has no reg property, the @ and unit-address must
>  be omitted ..."
>
> So you cannot have the "@8.0" without a "reg" property.

This terminology was suggested by Rob Herring due to the fact that
there were no previous examples.

Rob: care to comment?

Right now I have that distinct feeling of despair as the v8 patch set
is still stuck in DT syntax discussions...

Yours,
Linus Walleij

[PATCH 2/8 v2] leds: add device tree bindings for register bit LEDs

[Linus Walleij]

On Tue, Sep 2, 2014 at 2:24 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Tuesday 02 September 2014 14:02:28 Linus Walleij wrote:
>> +LED sub-node properties:
>> +
>> +Required properties:
>> +- compatible : must be "register-bit-led"
>> +- offset : register offset to the register controlling this LED
>> +- mask : bit mask for the bit controlling this LED in the register
>> +  typically 0x01, 0x02, 0x04 ...
>>
>
> How does the driver know whether to do byte or word sized accesses?

Like with all other bindings based on
Documentation/devicetree/bindings/mfd/syscon.txt
it is implicit that the access size is 32 bit words. Just grep
for syscon in the bindings and you will see none define the access
width.

If this should be fixed, the parent syscon binding should be
altered to cover access width for all children as this is a property
of the entire register range.

So for example:

gpr: iomuxc-gpr at 020e0000 {
        compatible = "fsl,imx6q-iomuxc-gpr", "syscon";
        reg = <0x020e0000 0x38>;
        register-width = <32>;
        register-valid = <32>;
        register-stride = <4>;
};

So as to indicate that this register range is made up of 32 bit
words, all 32 bits are valid in each word, and the stride between
words i 4 bytes (i.e. tightly packed).

As mentioned by Rob, the "syscon" driver should be renamed
"register-range" and "syscon" deprecated as binding, as it is
Linux terminology.

I guess this adds up to the conclusion that the "syscon" binding
was badly reviewed and merged, and now we're suffering from it.

----

Not that anyone should care when reviewing device tree bindings,
but as it happens, the Linux driver
drivers/mfd/syscon.c
explicitly assumes all sycons are 32bit:

static struct regmap_config syscon_regmap_config = {
        .reg_bits = 32,
        .val_bits = 32,
        .reg_stride = 4,
};

If one happens to work on Linux (we would never assume such a
thing, but if one by infinitesimal chance would still happen to do that)
we can leave a note in this posting that the syscon driver would need to
be altered to marshall it's regmap differently on stumbling onto this
new property.

Yours,
Linus Walleij