[PATCH v5 0/8] Add board support for TS-4600

[PATCH v5 0/8] Add board support for TS-4600

[Sebastien Bourdelin]

This patch serie adds support for the TS-4600 boards rev A and B. These
boards, manufactured by Technologic Systems, are based on an i.MX28.

This serie include the support for the watchdog which could be enable
at Linux boot time depending on the bootloader.

The watchdog and few peripherals are implemented in a FPGA, and can
only be access using a custom GPIOs bit-banged bus which is called the
NBUS by Technologic Systems.
A driver for this bus is also included and used by the watchdog.

Sebastien Bourdelin (8):
  of: documentation: add bindings documentation for TS-4600
  ARM: dts: TS-4600: add basic device tree
  dt-bindings: bus: Add documentation for the Technologic Systems NBUS
  bus: add driver for the Technologic Systems NBUS
  ARM: dts: TS-4600: add NBUS support
  dt-bindings: watchdog: add documentation for TS4600 watchdog
    controller
  watchdog: TS-4600: add driver for TS-4600 watchdog controller
  ARM: dts: TS-4600: add watchdog support

 .../devicetree/bindings/arm/technologic.txt        |   5 +
 Documentation/devicetree/bindings/bus/ts-nbus.txt  |  50 +++
 .../devicetree/bindings/watchdog/ts4600-wdt.txt    |  16 +
 arch/arm/boot/dts/Makefile                         |   2 +
 arch/arm/boot/dts/imx28-ts4600-common.dtsi         | 126 +++++++
 arch/arm/boot/dts/imx28-ts4600-rev-a.dts           |  22 ++
 arch/arm/boot/dts/imx28-ts4600-rev-b.dts           |  22 ++
 drivers/bus/Kconfig                                |   8 +
 drivers/bus/Makefile                               |   1 +
 drivers/bus/ts-nbus.c                              | 375 +++++++++++++++++++++
 drivers/watchdog/Kconfig                           |  11 +
 drivers/watchdog/Makefile                          |   1 +
 drivers/watchdog/ts4600_wdt.c                      | 185 ++++++++++
 include/linux/ts-nbus.h                            |  18 +
 14 files changed, 842 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/ts-nbus.txt
 create mode 100644 Documentation/devicetree/bindings/watchdog/ts4600-wdt.txt
 create mode 100644 arch/arm/boot/dts/imx28-ts4600-common.dtsi
 create mode 100644 arch/arm/boot/dts/imx28-ts4600-rev-a.dts
 create mode 100644 arch/arm/boot/dts/imx28-ts4600-rev-b.dts
 create mode 100644 drivers/bus/ts-nbus.c
 create mode 100644 drivers/watchdog/ts4600_wdt.c
 create mode 100644 include/linux/ts-nbus.h

-- 
2.13.0

[PATCH v5 1/8] of: documentation: add bindings documentation for TS-4600

[Sebastien Bourdelin]

This adds the documentation for the TS-4600 by Technologic Systems.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
---
Changes v4 -> v5:
  - fix missing signed off

Changes v3 -> v4:
  - rebase on master

Changes v2 -> v3:
  - rebase on master

Changes v1 -> v2:
  - rebase on master
  - add ack by Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/arm/technologic.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/technologic.txt b/Documentation/devicetree/bindings/arm/technologic.txt
index 33797acad846..e9d6d6575566 100644
--- a/Documentation/devicetree/bindings/arm/technologic.txt
+++ b/Documentation/devicetree/bindings/arm/technologic.txt
@@ -1,6 +1,11 @@
 Technologic Systems Platforms Device Tree Bindings
 --------------------------------------------------
 
+TS-4600 is a System-on-Module based on the Freescale i.MX28 System-on-Chip.
+It can be mounted on a carrier board providing additional peripheral connectors.
+Required root node properties:
+	- compatible = "technologic,imx28-ts4600", "fsl,imx28"
+
 TS-4800 board
 Required root node properties:
 	- compatible = "technologic,imx51-ts4800", "fsl,imx51";
-- 
2.13.0

[PATCH v5 2/8] ARM: dts: TS-4600: add basic device tree

[Sebastien Bourdelin]

These device trees add support for the TS-4600 by Technologic Systems.

More details here:
  http://wiki.embeddedarm.com/wiki/TS-4600

Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
---
Changes v4 -> v5:
  - fix missing signed off

Changes v3 -> v4:
  - rebase on master

Changes v2 -> v3:
  - rebase on master

Changes v1 -> v2:
  - rebase on master
---
 arch/arm/boot/dts/Makefile                 |  2 +
 arch/arm/boot/dts/imx28-ts4600-common.dtsi | 78 ++++++++++++++++++++++++++++++
 arch/arm/boot/dts/imx28-ts4600-rev-a.dts   | 22 +++++++++
 arch/arm/boot/dts/imx28-ts4600-rev-b.dts   | 22 +++++++++
 4 files changed, 124 insertions(+)
 create mode 100644 arch/arm/boot/dts/imx28-ts4600-common.dtsi
 create mode 100644 arch/arm/boot/dts/imx28-ts4600-rev-a.dts
 create mode 100644 arch/arm/boot/dts/imx28-ts4600-rev-b.dts

diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index 4b17f35dc9a7..a3c8b7af192b 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -525,6 +525,8 @@ dtb-$(CONFIG_ARCH_MXS) += \
 	imx28-m28cu3.dtb \
 	imx28-m28evk.dtb \
 	imx28-sps1.dtb \
+	imx28-ts4600-rev-a.dtb \
+	imx28-ts4600-rev-b.dtb \
 	imx28-tx28.dtb
 dtb-$(CONFIG_ARCH_NOMADIK) += \
 	ste-nomadik-s8815.dtb \
diff --git a/arch/arm/boot/dts/imx28-ts4600-common.dtsi b/arch/arm/boot/dts/imx28-ts4600-common.dtsi
new file mode 100644
index 000000000000..04bd5a5c0cb4
--- /dev/null
+++ b/arch/arm/boot/dts/imx28-ts4600-common.dtsi
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2016 Savoir-Faire Linux
+ * Author: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/dts-v1/;
+#include "imx28.dtsi"
+#include "dt-bindings/gpio/gpio.h"
+
+/ {
+
+	compatible = "technologic,imx28-ts4600", "fsl,imx28";
+
+	apb@80000000 {
+		apbh@80000000 {
+			ssp0: ssp@80010000 {
+				compatible = "fsl,imx28-mmc";
+				pinctrl-names = "default";
+				pinctrl-0 = <&mmc0_4bit_pins_a
+					     &mmc0_sck_cfg
+					     &en_sd_pwr>;
+				broken-cd = <1>;
+				bus-width = <4>;
+				vmmc-supply = <&reg_vddio_sd0>;
+				status = "okay";
+			};
+
+			pinctrl@80018000 {
+				pinctrl-names = "default";
+
+				en_sd_pwr: en_sd_pwr {
+					fsl,pinmux-ids = <
+						MX28_PAD_PWM3__GPIO_3_28
+					>;
+					fsl,drive-strength = <MXS_DRIVE_4mA>;
+					fsl,voltage = <MXS_VOLTAGE_HIGH>;
+					fsl,pull-up = <MXS_PULL_DISABLE>;
+				};
+
+			};
+		};
+
+		apbx@80040000 {
+			pwm: pwm@80064000 {
+				pinctrl-names = "default";
+				pinctrl-0 = <&pwm2_pins_a>;
+				status = "okay";
+			};
+
+			duart: serial@80074000 {
+				pinctrl-names = "default";
+				pinctrl-0 = <&duart_pins_a>;
+				status = "okay";
+			};
+		};
+	};
+
+	regulators {
+		compatible = "simple-bus";
+
+		reg_vddio_sd0: vddio-sd0 {
+			compatible = "regulator-fixed";
+			regulator-name = "vddio-sd0";
+			regulator-min-microvolt = <3300000>;
+			regulator-max-microvolt = <3300000>;
+			regulator-boot-on;
+			gpio = <&gpio3 28 0>;
+		};
+	};
+
+};
diff --git a/arch/arm/boot/dts/imx28-ts4600-rev-a.dts b/arch/arm/boot/dts/imx28-ts4600-rev-a.dts
new file mode 100644
index 000000000000..e8cb72988fcf
--- /dev/null
+++ b/arch/arm/boot/dts/imx28-ts4600-rev-a.dts
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2016 Savoir-Faire Linux
+ * Author: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include "imx28-ts4600-common.dtsi"
+
+/ {
+	model = "Technologic Systems i.MX28 TS-4600 Rev A";
+
+	memory {
+		reg = <0x40000000 0x08000000>;   /* 128MB */
+	};
+
+};
diff --git a/arch/arm/boot/dts/imx28-ts4600-rev-b.dts b/arch/arm/boot/dts/imx28-ts4600-rev-b.dts
new file mode 100644
index 000000000000..a115f831fe2b
--- /dev/null
+++ b/arch/arm/boot/dts/imx28-ts4600-rev-b.dts
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2016 Savoir-Faire Linux
+ * Author: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include "imx28-ts4600-common.dtsi"
+
+/ {
+	model = "Technologic Systems i.MX28 TS-4600 Rev B";
+
+	memory {
+		reg = <0x40000000 0x10000000>;   /* 256MB */
+	};
+
+};
-- 
2.13.0

[PATCH v5 3/8] dt-bindings: bus: Add documentation for the Technologic Systems NBUS

[Sebastien Bourdelin]

Add binding documentation for the Technologic Systems NBUS that is used
to interface with peripherals in the FPGA of the TS-4600 SoM.

Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
---
Changes v4 -> v5:
  - fix missing signed off

Changes v3 -> v4:
  - rebase on master
  - fix vendor prefixes for dts properties (suggested by Rob Herring)
  - v3 was acked by Linus Walleij

Changes v2 -> v3:
  - rebase on master
  - fix typo (suggested by Rob Herring)

Changes v1 -> v2:
  - rebase on master
  - remove the simple-bus compatibility as the root node will now
  populate child nodes (suggested by Rob Herring)
  - use the ts vendor prefix for gpios (suggested by Rob Herring)
---
 Documentation/devicetree/bindings/bus/ts-nbus.txt | 50 +++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/ts-nbus.txt

diff --git a/Documentation/devicetree/bindings/bus/ts-nbus.txt b/Documentation/devicetree/bindings/bus/ts-nbus.txt
new file mode 100644
index 000000000000..2a10d065b9fa
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/ts-nbus.txt
@@ -0,0 +1,50 @@
+Technologic Systems NBUS
+
+The NBUS is a bus used to interface with peripherals in the Technologic
+Systems FPGA on the TS-4600 SoM.
+
+Required properties :
+ - compatible		: "technologic,ts-nbus"
+ - #address-cells	: must be 1
+ - #size-cells		: must be 0
+ - pwms			: The PWM bound to the FPGA
+ - ts,data-gpios	: The 8 GPIO pins connected to the data lines on the FPGA
+ - ts,csn-gpios		: The GPIO pin connected to the csn line on the FPGA
+ - ts,txrx-gpios	: The GPIO pin connected to the txrx line on the FPGA
+ - ts,strobe-gpios	: The GPIO pin connected to the stobe line on the FPGA
+ - ts,ale-gpios		: The GPIO pin connected to the ale line on the FPGA
+ - ts,rdy-gpios		: The GPIO pin connected to the rdy line on the FPGA
+
+Child nodes:
+
+The NBUS node can contain zero or more child nodes representing peripherals
+on the bus.
+
+Example:
+
+	nbus {
+		compatible = "technologic,ts-nbus";
+		pinctrl-0 = <&nbus_pins>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		pwms = <&pwm 2 83>;
+		ts,data-gpios   = <&gpio0 0 GPIO_ACTIVE_HIGH
+				   &gpio0 1 GPIO_ACTIVE_HIGH
+				   &gpio0 2 GPIO_ACTIVE_HIGH
+				   &gpio0 3 GPIO_ACTIVE_HIGH
+				   &gpio0 4 GPIO_ACTIVE_HIGH
+				   &gpio0 5 GPIO_ACTIVE_HIGH
+				   &gpio0 6 GPIO_ACTIVE_HIGH
+				   &gpio0 7 GPIO_ACTIVE_HIGH>;
+		ts,csn-gpios    = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+		ts,txrx-gpios   = <&gpio0 24 GPIO_ACTIVE_HIGH>;
+		ts,strobe-gpios = <&gpio0 25 GPIO_ACTIVE_HIGH>;
+		ts,ale-gpios    = <&gpio0 26 GPIO_ACTIVE_HIGH>;
+		ts,rdy-gpios    = <&gpio0 21 GPIO_ACTIVE_HIGH>;
+
+		watchdog@2a {
+			compatible = "...";
+
+			/* ... */
+		};
+	};
-- 
2.13.0

[PATCH v5 4/8] bus: add driver for the Technologic Systems NBUS

[Sebastien Bourdelin]

This driver implements a GPIOs bit-banged bus, called the NBUS by
Technologic Systems. It is used to communicate with the peripherals in
the FPGA on the TS-4600 SoM.

Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
---
Changes v4 -> v5:
  - fix missing signed off

Changes v3 -> v4:
  - rebase on master
  - fix vendor prefixes for dts properties (suggested by Rob Herring)
  - v3 was acked by Linus Walleij

Changes v2 -> v3:
  - rebase on master
  - remove all call to the "inline" keyword in functions to let the
  compiler decide when required (suggested by Linus Walleij)
  - move the struct ts_nbus to the driver code instead of its header
  file (suggested by Linus Walleij)
  - use the bitops header and the BIT macro (suggested by Linus Walleij)
  - move the mutex to the struct ts_nbus instead to have it statically
  declared in the driver code (suggested by Linus Walleij)
  - remove the ts_nbus_set_mode function to simplify the logic
  (suggested by Linus Walleij)
  - the nbus will always need 8 data lines, remove the use of the
  ndescs when dealing with the data gpios and hardcode the value for
  simplicity instead (suggested by Linus Walleij)
  - add more comments (suggested by Linus Walleij)
  - rework all the ts_nbus_read_... functions to propagate the
  gpiod_get_value_... errno code (suggested by Linus Walleij)
  - few typos and code reformating for lisibility

Changes v1 -> v2:
  - rebase on master
  - the driver now populate its child nodes
  - remove the 'default y' option from the Kconfig
  - rework the driver to not use singleton anymore (suggested by Linus
  Walleij)
  - replace the use of the legacy GPIO API with gpiod (suggested by
  Linus Walleij)
  - use the ts vendor prefix for gpios (suggested by Rob Herring)
---
 drivers/bus/Kconfig     |   8 ++
 drivers/bus/Makefile    |   1 +
 drivers/bus/ts-nbus.c   | 375 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/ts-nbus.h |  18 +++
 4 files changed, 402 insertions(+)
 create mode 100644 drivers/bus/ts-nbus.c
 create mode 100644 include/linux/ts-nbus.h

diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 2408ea38a39c..3465e0decac5 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -157,6 +157,14 @@ config TEGRA_GMI
 	  Driver for the Tegra Generic Memory Interface bus which can be used
 	  to attach devices such as NOR, UART, FPGA and more.
 
+config TS_NBUS
+	tristate "Technologic Systems NBUS Driver"
+	depends on SOC_IMX28
+	depends on OF_GPIO && PWM
+	help
+	  Driver for the Technologic Systems NBUS which is used to interface
+	  with the peripherals in the FPGA of the TS-4600 SoM.
+
 config UNIPHIER_SYSTEM_BUS
 	tristate "UniPhier System Bus driver"
 	depends on ARCH_UNIPHIER && OF
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index cc6364bec054..72377f77651c 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_SUNXI_RSB)		+= sunxi-rsb.o
 obj-$(CONFIG_SIMPLE_PM_BUS)	+= simple-pm-bus.o
 obj-$(CONFIG_TEGRA_ACONNECT)	+= tegra-aconnect.o
 obj-$(CONFIG_TEGRA_GMI)		+= tegra-gmi.o
+obj-$(CONFIG_TS_NBUS)		+= ts-nbus.o
 obj-$(CONFIG_UNIPHIER_SYSTEM_BUS)	+= uniphier-system-bus.o
 obj-$(CONFIG_VEXPRESS_CONFIG)	+= vexpress-config.o
 
diff --git a/drivers/bus/ts-nbus.c b/drivers/bus/ts-nbus.c
new file mode 100644
index 000000000000..073fd9011154
--- /dev/null
+++ b/drivers/bus/ts-nbus.c
@@ -0,0 +1,375 @@
+/*
+ * NBUS driver for TS-4600 based boards
+ *
+ * Copyright (c) 2016 - Savoir-faire Linux
+ * Author: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
+ *
+ * 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.
+ *
+ * This driver implements a GPIOs bit-banged bus, called the NBUS by Technologic
+ * Systems. It is used to communicate with the peripherals in the FPGA on the
+ * TS-4600 SoM.
+ */
+
+#include <linux/bitops.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/ts-nbus.h>
+
+#define TS_NBUS_DIRECTION_IN  0
+#define TS_NBUS_DIRECTION_OUT 1
+#define TS_NBUS_WRITE_ADR 0
+#define TS_NBUS_WRITE_VAL 1
+
+struct ts_nbus {
+	struct pwm_device *pwm;
+	struct gpio_descs *data;
+	struct gpio_desc *csn;
+	struct gpio_desc *txrx;
+	struct gpio_desc *strobe;
+	struct gpio_desc *ale;
+	struct gpio_desc *rdy;
+	struct mutex lock;
+};
+
+/*
+ * request all gpios required by the bus.
+ */
+static int ts_nbus_init_pdata(struct platform_device *pdev, struct ts_nbus
+		*ts_nbus)
+{
+	ts_nbus->data = devm_gpiod_get_array(&pdev->dev, "ts,data",
+			GPIOD_OUT_HIGH);
+	if (IS_ERR(ts_nbus->data)) {
+		dev_err(&pdev->dev, "failed to retrieve ts,data-gpio from dts\n");
+		return PTR_ERR(ts_nbus->data);
+	}
+
+	ts_nbus->csn = devm_gpiod_get(&pdev->dev, "ts,csn", GPIOD_OUT_HIGH);
+	if (IS_ERR(ts_nbus->csn)) {
+		dev_err(&pdev->dev, "failed to retrieve ts,csn-gpio from dts\n");
+		return PTR_ERR(ts_nbus->csn);
+	}
+
+	ts_nbus->txrx = devm_gpiod_get(&pdev->dev, "ts,txrx", GPIOD_OUT_HIGH);
+	if (IS_ERR(ts_nbus->txrx)) {
+		dev_err(&pdev->dev, "failed to retrieve ts,txrx-gpio from dts\n");
+		return PTR_ERR(ts_nbus->txrx);
+	}
+
+	ts_nbus->strobe = devm_gpiod_get(&pdev->dev, "ts,strobe", GPIOD_OUT_HIGH);
+	if (IS_ERR(ts_nbus->strobe)) {
+		dev_err(&pdev->dev, "failed to retrieve ts,strobe-gpio from dts\n");
+		return PTR_ERR(ts_nbus->strobe);
+	}
+
+	ts_nbus->ale = devm_gpiod_get(&pdev->dev, "ts,ale", GPIOD_OUT_HIGH);
+	if (IS_ERR(ts_nbus->ale)) {
+		dev_err(&pdev->dev, "failed to retrieve ts,ale-gpio from dts\n");
+		return PTR_ERR(ts_nbus->ale);
+	}
+
+	ts_nbus->rdy = devm_gpiod_get(&pdev->dev, "ts,rdy", GPIOD_IN);
+	if (IS_ERR(ts_nbus->rdy)) {
+		dev_err(&pdev->dev, "failed to retrieve ts,rdy-gpio from dts\n");
+		return PTR_ERR(ts_nbus->rdy);
+	}
+
+	return 0;
+}
+
+/*
+ * the data gpios are used for reading and writing values, their directions
+ * should be adjusted accordingly.
+ */
+static void ts_nbus_set_direction(struct ts_nbus *ts_nbus, int direction)
+{
+	int i;
+
+	for (i = 0; i < 8; i++) {
+		if (direction == TS_NBUS_DIRECTION_IN)
+			gpiod_direction_input(ts_nbus->data->desc[i]);
+		else
+			/* when used as output the default state of the data
+			 * lines are set to high */
+			gpiod_direction_output(ts_nbus->data->desc[i], 1);
+	}
+}
+
+/*
+ * reset the bus in its initial state.
+ * The data, csn, strobe and ale lines must be zero'ed to let the FPGA knows a
+ * new transaction can be process.
+ */
+static void ts_nbus_reset_bus(struct ts_nbus *ts_nbus)
+{
+	int i;
+	int values[8];
+
+	for (i = 0; i < 8; i++)
+		values[i] = 0;
+
+	gpiod_set_array_value_cansleep(8, ts_nbus->data->desc, values);
+	gpiod_set_value_cansleep(ts_nbus->csn, 0);
+	gpiod_set_value_cansleep(ts_nbus->strobe, 0);
+	gpiod_set_value_cansleep(ts_nbus->ale, 0);
+}
+
+/*
+ * let the FPGA knows it can process.
+ */
+static void ts_nbus_start_transaction(struct ts_nbus *ts_nbus)
+{
+	gpiod_set_value_cansleep(ts_nbus->strobe, 1);
+}
+
+/*
+ * read a byte value from the data gpios.
+ * return 0 on success or negative errno on failure.
+ */
+static int ts_nbus_read_byte(struct ts_nbus *ts_nbus, u8 *val)
+{
+	struct gpio_descs *gpios = ts_nbus->data;
+	int ret, i;
+
+	*val = 0;
+	for (i = 0; i < 8; i++) {
+		ret = gpiod_get_value_cansleep(gpios->desc[i]);
+		if (ret < 0)
+			return ret;
+		if (ret)
+			*val |= BIT(i);
+	}
+
+	return 0;
+}
+
+/*
+ * set the data gpios accordingly to the byte value.
+ */
+static void ts_nbus_write_byte(struct ts_nbus *ts_nbus, u8 byte)
+{
+	struct gpio_descs *gpios = ts_nbus->data;
+	int i;
+	int values[8];
+
+	for (i = 0; i < 8; i++)
+		if (byte & BIT(i))
+			values[i] = 1;
+		else
+			values[i] = 0;
+
+	gpiod_set_array_value_cansleep(8, gpios->desc, values);
+}
+
+/*
+ * reading the bus consists of resetting the bus, then notifying the FPGA to
+ * send the data in the data gpios and return the read value.
+ * return 0 on success or negative errno on failure.
+ */
+static int ts_nbus_read_bus(struct ts_nbus *ts_nbus, u8 *val)
+{
+	ts_nbus_reset_bus(ts_nbus);
+	ts_nbus_start_transaction(ts_nbus);
+
+	return ts_nbus_read_byte(ts_nbus, val);
+}
+
+/*
+ * writing to the bus consists of resetting the bus, then define the type of
+ * command (address/value), write the data and notify the FPGA to retrieve the
+ * value in the data gpios.
+ */
+static void ts_nbus_write_bus(struct ts_nbus *ts_nbus, int cmd, u8 val)
+{
+	ts_nbus_reset_bus(ts_nbus);
+
+	if (cmd == TS_NBUS_WRITE_ADR)
+		gpiod_set_value_cansleep(ts_nbus->ale, 1);
+
+	ts_nbus_write_byte(ts_nbus, val);
+	ts_nbus_start_transaction(ts_nbus);
+}
+
+/*
+ * read the value in the FPGA register at the given address.
+ * return 0 on success or negative errno on failure.
+ */
+int ts_nbus_read(struct ts_nbus *ts_nbus, u8 adr, u16 *val)
+{
+	int ret, i;
+	u8 byte;
+
+	/* bus access must be atomic */
+	mutex_lock(&ts_nbus->lock);
+
+	/* set the bus in read mode */
+	gpiod_set_value_cansleep(ts_nbus->txrx, 0);
+
+	/* write address */
+	ts_nbus_write_bus(ts_nbus, TS_NBUS_WRITE_ADR, adr);
+
+	/* set the data gpios direction as input before reading */
+	ts_nbus_set_direction(ts_nbus, TS_NBUS_DIRECTION_IN);
+
+	/* reading value MSB first */
+	do {
+		*val = 0;
+		byte = 0;
+		for (i = 1; i >= 0; i--) {
+			/* read a byte from the bus, leave on error */
+			ret = ts_nbus_read_bus(ts_nbus, &byte);
+			if (ret < 0)
+				goto err;
+
+			/* append the byte read to the final value */
+			*val |= byte << (i * 8);
+		}
+		gpiod_set_value_cansleep(ts_nbus->csn, 1);
+		ret = gpiod_get_value_cansleep(ts_nbus->rdy);
+	} while (ret);
+
+err:
+	/* restore the data gpios direction as output after reading */
+	ts_nbus_set_direction(ts_nbus, TS_NBUS_DIRECTION_OUT);
+
+	mutex_unlock(&ts_nbus->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ts_nbus_read);
+
+/*
+ * write the desired value in the FPGA register at the given address.
+ */
+int ts_nbus_write(struct ts_nbus *ts_nbus, u8 adr, u16 val)
+{
+	int i;
+
+	/* bus access must be atomic */
+	mutex_lock(&ts_nbus->lock);
+
+	/* set the bus in write mode */
+	gpiod_set_value_cansleep(ts_nbus->txrx, 1);
+
+	/* write address */
+	ts_nbus_write_bus(ts_nbus, TS_NBUS_WRITE_ADR, adr);
+
+	/* writing value MSB first */
+	for (i = 1; i >= 0; i--)
+		ts_nbus_write_bus(ts_nbus, TS_NBUS_WRITE_VAL, (u8)(val >> (i * 8)));
+
+	/* wait for completion */
+	gpiod_set_value_cansleep(ts_nbus->csn, 1);
+	while (gpiod_get_value_cansleep(ts_nbus->rdy) != 0) {
+		gpiod_set_value_cansleep(ts_nbus->csn, 0);
+		gpiod_set_value_cansleep(ts_nbus->csn, 1);
+	}
+
+	mutex_unlock(&ts_nbus->lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ts_nbus_write);
+
+static int ts_nbus_probe(struct platform_device *pdev)
+{
+	struct pwm_device *pwm;
+	struct pwm_args pargs;
+	struct device *dev = &pdev->dev;
+	struct ts_nbus *ts_nbus;
+	int ret;
+
+	ts_nbus = devm_kzalloc(dev, sizeof(*ts_nbus), GFP_KERNEL);
+	if (!ts_nbus)
+		return -ENOMEM;
+
+	mutex_init(&ts_nbus->lock);
+
+	ret = ts_nbus_init_pdata(pdev, ts_nbus);
+	if (ret < 0)
+		return ret;
+
+	pwm = devm_pwm_get(dev, NULL);
+	if (IS_ERR(pwm)) {
+		ret = PTR_ERR(pwm);
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "unable to request PWM\n");
+		return ret;
+	}
+
+	pwm_get_args(pwm, &pargs);
+	if (!pargs.period) {
+		dev_err(&pdev->dev, "invalid PWM period\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * FIXME: pwm_apply_args() should be removed when switching to
+	 * the atomic PWM API.
+	 */
+	pwm_apply_args(pwm);
+	ret = pwm_config(pwm, pargs.period, pargs.period);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * we can now start the FPGA and populate the peripherals.
+	 */
+	pwm_enable(pwm);
+	ts_nbus->pwm = pwm;
+
+	/*
+	 * let the child nodes retrieve this instance of the ts-nbus.
+	 */
+	dev_set_drvdata(dev, ts_nbus);
+
+	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
+	if (ret < 0)
+		return ret;
+
+	dev_info(dev, "initialized\n");
+
+	return 0;
+}
+
+static int ts_nbus_remove(struct platform_device *pdev)
+{
+	struct ts_nbus *ts_nbus = dev_get_drvdata(&pdev->dev);
+
+	/* shutdown the FPGA */
+	mutex_lock(&ts_nbus->lock);
+	pwm_disable(ts_nbus->pwm);
+	mutex_unlock(&ts_nbus->lock);
+
+	return 0;
+}
+
+static const struct of_device_id ts_nbus_of_match[] = {
+	{ .compatible = "technologic,ts-nbus", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ts_nbus_of_match);
+
+static struct platform_driver ts_nbus_driver = {
+	.probe		= ts_nbus_probe,
+	.remove		= ts_nbus_remove,
+	.driver		= {
+		.name	= "ts_nbus",
+		.of_match_table = ts_nbus_of_match,
+	},
+};
+
+module_platform_driver(ts_nbus_driver);
+
+MODULE_ALIAS("platform:ts_nbus");
+MODULE_AUTHOR("Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>");
+MODULE_DESCRIPTION("Technologic Systems NBUS");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/ts-nbus.h b/include/linux/ts-nbus.h
new file mode 100644
index 000000000000..5bd4c822f7cf
--- /dev/null
+++ b/include/linux/ts-nbus.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2016 - Savoir-faire Linux
+ * Author: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
+ *
+ * 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.
+ */
+
+#ifndef _TS_NBUS_H
+#define _TS_NBUS_H
+
+struct ts_nbus;
+
+extern int ts_nbus_read(struct ts_nbus *ts_nbus, u8 adr, u16 *val);
+extern int ts_nbus_write(struct ts_nbus *ts_nbus, u8 adr, u16 val);
+
+#endif /* _TS_NBUS_H */
-- 
2.13.0

[PATCH v5 5/8] ARM: dts: TS-4600: add NBUS support

[Sebastien Bourdelin]

This commit enables the NBUS on the TS-4600, using the ts-nbus driver.

Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
---
Changes v4 -> v5:
  - fix missing signed off

Changes v3 -> v4:
  - rebase on master
  - fix vendor prefixes for dts properties (suggested by Rob Herring)
  - v3 was acked by Linus Walleij

Changes v2 -> v3:
  - rebase on master

Changes v1 -> v2:
  - rebase on master
  - remove the simple-bus compatibility as the root node will now
  populate the child nodes (suggested by Rob Herring)
  - add the vendor prefix to all gpio (suggested by Rob Herring)
---
 arch/arm/boot/dts/imx28-ts4600-common.dtsi | 43 ++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/arch/arm/boot/dts/imx28-ts4600-common.dtsi b/arch/arm/boot/dts/imx28-ts4600-common.dtsi
index 04bd5a5c0cb4..a90bd934e4a3 100644
--- a/arch/arm/boot/dts/imx28-ts4600-common.dtsi
+++ b/arch/arm/boot/dts/imx28-ts4600-common.dtsi
@@ -44,6 +44,28 @@
 					fsl,pull-up = <MXS_PULL_DISABLE>;
 				};
 
+				nbus_pins: nbus_pins {
+					fsl,pinmux-ids = <
+						MX28_PAD_GPMI_D00__GPIO_0_0
+						MX28_PAD_GPMI_D01__GPIO_0_1
+						MX28_PAD_GPMI_D02__GPIO_0_2
+						MX28_PAD_GPMI_D03__GPIO_0_3
+						MX28_PAD_GPMI_D04__GPIO_0_4
+						MX28_PAD_GPMI_D05__GPIO_0_5
+						MX28_PAD_GPMI_D06__GPIO_0_6
+						MX28_PAD_GPMI_D07__GPIO_0_7
+						MX28_PAD_GPMI_CE0N__GPIO_0_16
+						MX28_PAD_GPMI_RDY1__GPIO_0_21
+						MX28_PAD_GPMI_RDN__GPIO_0_24
+						MX28_PAD_GPMI_WRN__GPIO_0_25
+						MX28_PAD_GPMI_ALE__GPIO_0_26
+					>;
+					fsl,drive-strength = <MXS_DRIVE_4mA>;
+					fsl,voltage = <MXS_VOLTAGE_HIGH>;
+					fsl,pull-up = <MXS_PULL_DISABLE>;
+
+				};
+
 			};
 		};
 
@@ -75,4 +97,25 @@
 		};
 	};
 
+	nbus {
+		compatible = "technologic,ts-nbus";
+		pinctrl-0 = <&nbus_pins>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		pwms = <&pwm 2 83>;
+		ts,data-gpios   = <&gpio0 0 GPIO_ACTIVE_HIGH
+				   &gpio0 1 GPIO_ACTIVE_HIGH
+				   &gpio0 2 GPIO_ACTIVE_HIGH
+				   &gpio0 3 GPIO_ACTIVE_HIGH
+				   &gpio0 4 GPIO_ACTIVE_HIGH
+				   &gpio0 5 GPIO_ACTIVE_HIGH
+				   &gpio0 6 GPIO_ACTIVE_HIGH
+				   &gpio0 7 GPIO_ACTIVE_HIGH>;
+		ts,csn-gpios    = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+		ts,txrx-gpios   = <&gpio0 24 GPIO_ACTIVE_HIGH>;
+		ts,strobe-gpios = <&gpio0 25 GPIO_ACTIVE_HIGH>;
+		ts,ale-gpios    = <&gpio0 26 GPIO_ACTIVE_HIGH>;
+		ts,rdy-gpios    = <&gpio0 21 GPIO_ACTIVE_HIGH>;
+	};
+
 };
-- 
2.13.0

[PATCH v5 6/8] dt-bindings: watchdog: add documentation for TS4600 watchdog controller

[Sebastien Bourdelin]

This patch adds dt-binding documentation for TS4600 watchdog controller.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
---
Changes v4 -> v5:
  - fix missing signed off

v4:
  - this documentation was previously merged with the watchdog driver
  and had been acked by Rob Herring, no changes have been done since.
---
 .../devicetree/bindings/watchdog/ts4600-wdt.txt          | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/ts4600-wdt.txt

diff --git a/Documentation/devicetree/bindings/watchdog/ts4600-wdt.txt b/Documentation/devicetree/bindings/watchdog/ts4600-wdt.txt
new file mode 100644
index 000000000000..7de00ceae341
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/ts4600-wdt.txt
@@ -0,0 +1,16 @@
+TS-4600 Technologic Systems Watchdog
+
+Required properties:
+- compatible: must be "technologic,ts4600-wdt"
+- reg: offset to the FPGA's watchdog register
+
+Optional property:
+- timeout-sec: contains the watchdog timeout in seconds.
+
+Example:
+
+watchdog {
+	compatible = "technologic,ts4600-wdt";
+	reg = <0x2a>;
+	timeout-sec = <10>;
+};
-- 
2.13.0

[PATCH v5 7/8] watchdog: TS-4600: add driver for TS-4600 watchdog controller

[Sebastien Bourdelin]

This watchdog is instantiated in a FPGA and can only be access using a
GPIOs bit-banged bus, called the NBUS by Technologic Systems.
The watchdog is made of only one register, called the feed register.
Writing to this register will re-arm the watchdog for a given time (and
enable it if it was disable). It can be disabled by writing a special
value into it.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
---
Changes v4 -> v5:
  - fix missing signed off

Changes v3 -> v4:
  - rebase on master
  - remove the dts and the documentation associated from the driver
  commit (suggested by Shawn Guo)
  - the driver in v3 was acked by Guenter Roeck and no changes on the
  driver have been done.

Changes v2 -> v3:
  - rebase on master
  - remove the timeout table to simplify the logic (suggested by
  Guenter Roeck)
  - fix the set_timeout function (suggested by Guenter Roeck)
  - hardcode the max_hw_heartbeat_ms value based on the ts4600 max
  timeout value supported (suggested by Guenter Roeck)
  - remove the max_timeout usage and set a default timeout value
(suggested by Guenter Roeck)
  - use the devm_watchdog_register_device function instead of
  watchdog_register_device (suggested by Guenter Roeck)
  - v2 was acked by Rob Herring

Changes v1 -> v2:
  - rebase on master
  - retrieve the ts_nbus instantiated by the parent node (suggested by
  Linus Walleij)
  - rename the wdt by watchdog in the device tree and in the
  documentation (suggested by Rob Herring)
  - add a dependency to the TS_NBUS driver in the Kconfig (suggested by
  Guenter Roeck)
  - simplify the set_timeout function (suggested by Guenter Roeck)
  - use the max_hw_heartbeat_ms callback instead of the max_timeout
  callback (suggested by Guenter Roeck)
---
 drivers/watchdog/Kconfig      |  11 +++
 drivers/watchdog/Makefile     |   1 +
 drivers/watchdog/ts4600_wdt.c | 185 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 197 insertions(+)
 create mode 100644 drivers/watchdog/ts4600_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index c722cbfdc7e6..d50fbc232d9e 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -531,6 +531,17 @@ config NUC900_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called nuc900_wdt.
 
+config TS4600_WATCHDOG
+	tristate "TS-4600 Watchdog"
+	depends on TS_NBUS
+	depends on HAS_IOMEM && OF
+	depends on SOC_IMX28 || COMPILE_TEST
+	select WATCHDOG_CORE
+	help
+	  Technologic Systems TS-4600 has watchdog timer implemented in
+	  an external FPGA. Say Y here if you want to support for the
+	  watchdog timer on TS-4600 board.
+
 config TS4800_WATCHDOG
 	tristate "TS-4800 Watchdog"
 	depends on HAS_IOMEM && OF
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 56adf9fa67d0..a95aa4a13b39 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -62,6 +62,7 @@ obj-$(CONFIG_RN5T618_WATCHDOG) += rn5t618_wdt.o
 obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
 obj-$(CONFIG_STMP3XXX_RTC_WATCHDOG) += stmp3xxx_rtc_wdt.o
 obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
+obj-$(CONFIG_TS4600_WATCHDOG) += ts4600_wdt.o
 obj-$(CONFIG_TS4800_WATCHDOG) += ts4800_wdt.o
 obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
 obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
diff --git a/drivers/watchdog/ts4600_wdt.c b/drivers/watchdog/ts4600_wdt.c
new file mode 100644
index 000000000000..ed530dd2f800
--- /dev/null
+++ b/drivers/watchdog/ts4600_wdt.c
@@ -0,0 +1,185 @@
+/*
+ * Watchdog driver for TS-4600 based boards
+ *
+ * Copyright (c) 2016 - Savoir-faire Linux
+ * Author: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
+ *
+ * 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.
+ *
+ * The watchdog on the TS-4600 based boards is in an FPGA and can only be
+ * accessed using a GPIO bit-banged bus called the NBUS by Technologic Systems.
+ * The logic for the watchdog is the same then for the TS-4800 SoM, only the way
+ * to access it change, therefore this driver is heavely based on the ts4800_wdt
+ * driver from Damien Riegel <damien.riegel@savoirfairelinux.com>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/ts-nbus.h>
+#include <linux/watchdog.h>
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+	"Watchdog cannot be stopped once started (default="
+	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+/*
+ * TS-4600 supports the following timeout values:
+ *
+ *   value desc
+ *   ---------------------
+ *     0    feed for 338ms
+ *     1    feed for 2.706s
+ *     2    feed for 10.824s
+ *     3    disable watchdog
+ */
+#define TS4600_WDT_FEED_2S       0x1
+#define TS4600_WDT_FEED_10S      0x2
+#define TS4600_WDT_DISABLE       0x3
+
+struct ts4600_wdt {
+	struct watchdog_device  wdd;
+	struct ts_nbus		*ts_nbus;
+	u32                     feed_offset;
+	u32                     feed_val;
+};
+
+static void ts4600_write_feed(struct ts4600_wdt *wdt, u32 val)
+{
+	ts_nbus_write(wdt->ts_nbus, wdt->feed_offset, val);
+}
+
+static int ts4600_wdt_start(struct watchdog_device *wdd)
+{
+	struct ts4600_wdt *wdt = watchdog_get_drvdata(wdd);
+
+	ts4600_write_feed(wdt, wdt->feed_val);
+
+	return 0;
+}
+
+static int ts4600_wdt_stop(struct watchdog_device *wdd)
+{
+	struct ts4600_wdt *wdt = watchdog_get_drvdata(wdd);
+
+	ts4600_write_feed(wdt, TS4600_WDT_DISABLE);
+	return 0;
+}
+
+static int ts4600_wdt_set_timeout(struct watchdog_device *wdd,
+				  unsigned int timeout)
+{
+	struct ts4600_wdt *wdt = watchdog_get_drvdata(wdd);
+
+	if (timeout <= 2) {
+		wdd->timeout = 2;
+		wdt->feed_val = TS4600_WDT_FEED_2S;
+	} else {
+		wdd->timeout = timeout < 10 ? 10 : timeout;
+		wdt->feed_val = TS4600_WDT_FEED_10S;
+	}
+
+	return 0;
+}
+
+static const struct watchdog_ops ts4600_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = ts4600_wdt_start,
+	.stop = ts4600_wdt_stop,
+	.set_timeout = ts4600_wdt_set_timeout,
+};
+
+static const struct watchdog_info ts4600_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
+	.identity = "TS-4600 Watchdog",
+};
+
+static int ts4600_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct ts_nbus *ts_nbus;
+	struct watchdog_device *wdd;
+	struct ts4600_wdt *wdt;
+	u32 reg;
+	int ret;
+
+	ret = of_property_read_u32(np, "reg", &reg);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "missing reg property\n");
+		return ret;
+	}
+
+	/* allocate memory for watchdog struct */
+	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+	if (!wdt)
+		return -ENOMEM;
+
+	/* set offset to know where to write */
+	wdt->feed_offset = reg;
+
+	/* keep a pointer to the ts_nbus instanciated by the parent node */
+	ts_nbus = dev_get_drvdata(dev->parent);
+	if (!ts_nbus) {
+		dev_err(dev, "missing ts-nbus compatible parent node\n");
+		return PTR_ERR(ts_nbus);
+	}
+	wdt->ts_nbus = ts_nbus;
+
+	/* Initialize struct watchdog_device */
+	wdd = &wdt->wdd;
+	wdd->parent = dev;
+	wdd->info = &ts4600_wdt_info;
+	wdd->ops = &ts4600_wdt_ops;
+	wdd->min_timeout = 2;
+	wdd->max_hw_heartbeat_ms = 10824;
+	wdd->timeout = 30;
+
+	watchdog_set_drvdata(wdd, wdt);
+	watchdog_set_nowayout(wdd, nowayout);
+	watchdog_init_timeout(wdd, 0, dev);
+
+	ts4600_wdt_set_timeout(wdd, wdd->timeout);
+
+	/*
+	 * The feed register is write-only, so it is not possible to determine
+	 * watchdog's state. Disable it to be in a known state.
+	 */
+	ts4600_wdt_stop(wdd);
+
+	ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdd);
+	if (ret) {
+		dev_err(dev, "failed to register watchdog device\n");
+		return ret;
+	}
+
+	dev_info(dev, "initialized (timeout = %d sec, nowayout = %d)\n",
+		 wdd->timeout, nowayout);
+
+	return 0;
+}
+
+static const struct of_device_id ts4600_wdt_of_match[] = {
+	{ .compatible = "technologic,ts4600-wdt", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ts4600_wdt_of_match);
+
+static struct platform_driver ts4600_wdt_driver = {
+	.probe		= ts4600_wdt_probe,
+	.driver		= {
+		.name	= "ts4600_wdt",
+		.of_match_table = ts4600_wdt_of_match,
+	},
+};
+
+module_platform_driver(ts4600_wdt_driver);
+
+MODULE_AUTHOR("Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:ts4600_wdt");
-- 
2.13.0

[PATCH v5 8/8] ARM: dts: TS-4600: add watchdog support

[Sebastien Bourdelin]

This enables support for the watchdog located in the FPGA.

Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
---
Changes v4 -> v5:
  - fix missing signed off
---
 arch/arm/boot/dts/imx28-ts4600-common.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/imx28-ts4600-common.dtsi b/arch/arm/boot/dts/imx28-ts4600-common.dtsi
index a90bd934e4a3..9e177d33ba9c 100644
--- a/arch/arm/boot/dts/imx28-ts4600-common.dtsi
+++ b/arch/arm/boot/dts/imx28-ts4600-common.dtsi
@@ -116,6 +116,11 @@
 		ts,strobe-gpios = <&gpio0 25 GPIO_ACTIVE_HIGH>;
 		ts,ale-gpios    = <&gpio0 26 GPIO_ACTIVE_HIGH>;
 		ts,rdy-gpios    = <&gpio0 21 GPIO_ACTIVE_HIGH>;
+
+		watchdog@2a {
+			compatible = "technologic,ts4600-wdt";
+			reg = <0x2a>;
+		};
 	};
 
 };
-- 
2.13.0

Re: [PATCH v5 3/8] dt-bindings: bus: Add documentation for the Technologic Systems NBUS

[Rob Herring]

On Fri, Jul 14, 2017 at 04:32:13PM -0400, Sebastien Bourdelin wrote:
> Add binding documentation for the Technologic Systems NBUS that is used
> to interface with peripherals in the FPGA of the TS-4600 SoM.
> 
> Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
> ---
> Changes v4 -> v5:
>   - fix missing signed off
> 
> Changes v3 -> v4:
>   - rebase on master
>   - fix vendor prefixes for dts properties (suggested by Rob Herring)
>   - v3 was acked by Linus Walleij
> 
> Changes v2 -> v3:
>   - rebase on master
>   - fix typo (suggested by Rob Herring)
> 
> Changes v1 -> v2:
>   - rebase on master
>   - remove the simple-bus compatibility as the root node will now
>   populate child nodes (suggested by Rob Herring)
>   - use the ts vendor prefix for gpios (suggested by Rob Herring)
> ---
>  Documentation/devicetree/bindings/bus/ts-nbus.txt | 50 +++++++++++++++++++++++
>  1 file changed, 50 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/bus/ts-nbus.txt

Acked-by: Rob Herring <robh@kernel.org>

Re: [PATCH v5 4/8] bus: add driver for the Technologic Systems NBUS

[Linus Walleij]

On Fri, Jul 14, 2017 at 10:32 PM, Sebastien Bourdelin
<sebastien.bourdelin@savoirfairelinux.com> wrote:

> This driver implements a GPIOs bit-banged bus, called the NBUS by
> Technologic Systems. It is used to communicate with the peripherals in
> the FPGA on the TS-4600 SoM.
>
> Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
> ---
> Changes v4 -> v5:
>   - fix missing signed off

Acked-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH v5 3/8] dt-bindings: bus: Add documentation for the Technologic Systems NBUS

[Linus Walleij]

On Fri, Jul 14, 2017 at 10:32 PM, Sebastien Bourdelin
<sebastien.bourdelin@savoirfairelinux.com> wrote:

> Add binding documentation for the Technologic Systems NBUS that is used
> to interface with peripherals in the FPGA of the TS-4600 SoM.
>
> Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
> ---
> Changes v4 -> v5:
>   - fix missing signed off

Acked-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH v5 0/8] Add board support for TS-4600

[Shawn Guo]

On Fri, Jul 14, 2017 at 04:32:10PM -0400, Sebastien Bourdelin wrote:
> This patch serie adds support for the TS-4600 boards rev A and B. These
> boards, manufactured by Technologic Systems, are based on an i.MX28.
> 
> This serie include the support for the watchdog which could be enable
> at Linux boot time depending on the bootloader.
> 
> The watchdog and few peripherals are implemented in a FPGA, and can
> only be access using a custom GPIOs bit-banged bus which is called the
> NBUS by Technologic Systems.
> A driver for this bus is also included and used by the watchdog.
> 
> Sebastien Bourdelin (8):
>   of: documentation: add bindings documentation for TS-4600
>   ARM: dts: TS-4600: add basic device tree
>   dt-bindings: bus: Add documentation for the Technologic Systems NBUS
>   bus: add driver for the Technologic Systems NBUS
>   ARM: dts: TS-4600: add NBUS support
>   dt-bindings: watchdog: add documentation for TS4600 watchdog
>     controller
>   watchdog: TS-4600: add driver for TS-4600 watchdog controller
>   ARM: dts: TS-4600: add watchdog support

You are mixing changes on 3 subsystem in a single patch series.  It
makes the merge process unnecessarily hard.  I suggest you split the
series as following:

 - nbus dt-bindings and driver
 - watchdog dt-bindings and driver
 - ts-4600 board bindings and dts

You should get the first two into mainline through corresponding
subsystem tree, and then submit the last one to me.  In that case, NBUS
and watchdog dts changes do not have to be separate patches.

Shawn

Re: [PATCH v5 0/8] Add board support for TS-4600

[Sebastien Bourdelin]

On 08/02/2017 09:26 PM, Shawn Guo wrote:
> On Fri, Jul 14, 2017 at 04:32:10PM -0400, Sebastien Bourdelin wrote:
>> This patch serie adds support for the TS-4600 boards rev A and B. These
>> boards, manufactured by Technologic Systems, are based on an i.MX28.
>>
>> This serie include the support for the watchdog which could be enable
>> at Linux boot time depending on the bootloader.
>>
>> The watchdog and few peripherals are implemented in a FPGA, and can
>> only be access using a custom GPIOs bit-banged bus which is called the
>> NBUS by Technologic Systems.
>> A driver for this bus is also included and used by the watchdog.
>>
>> Sebastien Bourdelin (8):
>>   of: documentation: add bindings documentation for TS-4600
>>   ARM: dts: TS-4600: add basic device tree
>>   dt-bindings: bus: Add documentation for the Technologic Systems NBUS
>>   bus: add driver for the Technologic Systems NBUS
>>   ARM: dts: TS-4600: add NBUS support
>>   dt-bindings: watchdog: add documentation for TS4600 watchdog
>>     controller
>>   watchdog: TS-4600: add driver for TS-4600 watchdog controller
>>   ARM: dts: TS-4600: add watchdog support
> 
> You are mixing changes on 3 subsystem in a single patch series.  It
> makes the merge process unnecessarily hard.  I suggest you split the
> series as following:
> 
>  - nbus dt-bindings and driver
>  - watchdog dt-bindings and driver
>  - ts-4600 board bindings and dts
> 
> You should get the first two into mainline through corresponding
> subsystem tree, and then submit the last one to me.  In that case, NBUS
> and watchdog dts changes do not have to be separate patches.
> 
> Shawn
> 

Hi Shawn,

Thanks i understand, however if it's ok, i would like to process in the
same time with the TS4600 board bindings and initial dts without the
part related to the nbus and watchdog.
There is no dependencies here and we can accellerate the process.

Regards,
Sebastien.

Re: [PATCH v5 2/8] ARM: dts: TS-4600: add basic device tree

[Shawn Guo]

On Fri, Jul 14, 2017 at 04:32:12PM -0400, Sebastien Bourdelin wrote:
> These device trees add support for the TS-4600 by Technologic Systems.
> 
> More details here:
>   http://wiki.embeddedarm.com/wiki/TS-4600
> 
> Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
> ---
> Changes v4 -> v5:
>   - fix missing signed off
> 
> Changes v3 -> v4:
>   - rebase on master
> 
> Changes v2 -> v3:
>   - rebase on master
> 
> Changes v1 -> v2:
>   - rebase on master
> ---
>  arch/arm/boot/dts/Makefile                 |  2 +
>  arch/arm/boot/dts/imx28-ts4600-common.dtsi | 78 ++++++++++++++++++++++++++++++
>  arch/arm/boot/dts/imx28-ts4600-rev-a.dts   | 22 +++++++++
>  arch/arm/boot/dts/imx28-ts4600-rev-b.dts   | 22 +++++++++
>  4 files changed, 124 insertions(+)
>  create mode 100644 arch/arm/boot/dts/imx28-ts4600-common.dtsi
>  create mode 100644 arch/arm/boot/dts/imx28-ts4600-rev-a.dts
>  create mode 100644 arch/arm/boot/dts/imx28-ts4600-rev-b.dts
> 
> diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
> index 4b17f35dc9a7..a3c8b7af192b 100644
> --- a/arch/arm/boot/dts/Makefile
> +++ b/arch/arm/boot/dts/Makefile
> @@ -525,6 +525,8 @@ dtb-$(CONFIG_ARCH_MXS) += \
>  	imx28-m28cu3.dtb \
>  	imx28-m28evk.dtb \
>  	imx28-sps1.dtb \
> +	imx28-ts4600-rev-a.dtb \
> +	imx28-ts4600-rev-b.dtb \
>  	imx28-tx28.dtb
>  dtb-$(CONFIG_ARCH_NOMADIK) += \
>  	ste-nomadik-s8815.dtb \
> diff --git a/arch/arm/boot/dts/imx28-ts4600-common.dtsi b/arch/arm/boot/dts/imx28-ts4600-common.dtsi
> new file mode 100644
> index 000000000000..04bd5a5c0cb4
> --- /dev/null
> +++ b/arch/arm/boot/dts/imx28-ts4600-common.dtsi
> @@ -0,0 +1,78 @@
> +/*
> + * Copyright (C) 2016 Savoir-Faire Linux
> + * Author: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
> + *
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +
> +/dts-v1/;
> +#include "imx28.dtsi"
> +#include "dt-bindings/gpio/gpio.h"
> +
> +/ {
> +
> +	compatible = "technologic,imx28-ts4600", "fsl,imx28";
> +
> +	apb@80000000 {
> +		apbh@80000000 {
> +			ssp0: ssp@80010000 {
> +				compatible = "fsl,imx28-mmc";
> +				pinctrl-names = "default";
> +				pinctrl-0 = <&mmc0_4bit_pins_a
> +					     &mmc0_sck_cfg
> +					     &en_sd_pwr>;
> +				broken-cd = <1>;
> +				bus-width = <4>;
> +				vmmc-supply = <&reg_vddio_sd0>;
> +				status = "okay";
> +			};
> +
> +			pinctrl@80018000 {
> +				pinctrl-names = "default";

This line shouldn't be needed here.

> +
> +				en_sd_pwr: en_sd_pwr {

Please have a look at bindings/pinctrl/fsl,mxs-pinctrl.txt.  The node
without 'reg' property will be treated as a pure configuration rather
than pinmux node.  You should really have a 'reg' property for it.

Also, we prefer to use hyphen than underscore in node name.

> +					fsl,pinmux-ids = <
> +						MX28_PAD_PWM3__GPIO_3_28
> +					>;
> +					fsl,drive-strength = <MXS_DRIVE_4mA>;
> +					fsl,voltage = <MXS_VOLTAGE_HIGH>;
> +					fsl,pull-up = <MXS_PULL_DISABLE>;
> +				};
> +
> +			};
> +		};
> +
> +		apbx@80040000 {
> +			pwm: pwm@80064000 {
> +				pinctrl-names = "default";
> +				pinctrl-0 = <&pwm2_pins_a>;
> +				status = "okay";
> +			};
> +
> +			duart: serial@80074000 {
> +				pinctrl-names = "default";
> +				pinctrl-0 = <&duart_pins_a>;
> +				status = "okay";
> +			};
> +		};
> +	};
> +
> +	regulators {
> +		compatible = "simple-bus";
> +
> +		reg_vddio_sd0: vddio-sd0 {
> +			compatible = "regulator-fixed";
> +			regulator-name = "vddio-sd0";
> +			regulator-min-microvolt = <3300000>;
> +			regulator-max-microvolt = <3300000>;
> +			regulator-boot-on;
> +			gpio = <&gpio3 28 0>;

Please use the defines in include/dt-bindings/gpio/gpio.h for polarity
here?

> +		};
> +	};

We are asked by DT maintainers to put fixed regulator directly under
root instead of having a fake bus container node.  We prefer to use the
following naming schema:

	reg_xxx: regulator-xxx {
		...
	};

Shawn

> +
> +};
> diff --git a/arch/arm/boot/dts/imx28-ts4600-rev-a.dts b/arch/arm/boot/dts/imx28-ts4600-rev-a.dts
> new file mode 100644
> index 000000000000..e8cb72988fcf
> --- /dev/null
> +++ b/arch/arm/boot/dts/imx28-ts4600-rev-a.dts
> @@ -0,0 +1,22 @@
> +/*
> + * Copyright (C) 2016 Savoir-Faire Linux
> + * Author: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
> + *
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +
> +#include "imx28-ts4600-common.dtsi"
> +
> +/ {
> +	model = "Technologic Systems i.MX28 TS-4600 Rev A";
> +
> +	memory {
> +		reg = <0x40000000 0x08000000>;   /* 128MB */
> +	};
> +
> +};
> diff --git a/arch/arm/boot/dts/imx28-ts4600-rev-b.dts b/arch/arm/boot/dts/imx28-ts4600-rev-b.dts
> new file mode 100644
> index 000000000000..a115f831fe2b
> --- /dev/null
> +++ b/arch/arm/boot/dts/imx28-ts4600-rev-b.dts
> @@ -0,0 +1,22 @@
> +/*
> + * Copyright (C) 2016 Savoir-Faire Linux
> + * Author: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
> + *
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +
> +#include "imx28-ts4600-common.dtsi"
> +
> +/ {
> +	model = "Technologic Systems i.MX28 TS-4600 Rev B";
> +
> +	memory {
> +		reg = <0x40000000 0x10000000>;   /* 256MB */
> +	};
> +
> +};
> -- 
> 2.13.0
> 

Re: [PATCH v5 0/8] Add board support for TS-4600

[Shawn Guo]

On Thu, Aug 03, 2017 at 03:32:36PM -0400, Sebastien Bourdelin wrote:
> Hi Shawn,
> 
> Thanks i understand, however if it's ok, i would like to process in the
> same time with the TS4600 board bindings and initial dts without the
> part related to the nbus and watchdog.
> There is no dependencies here and we can accellerate the process.

Okay.  I just put a few comments on the initial dts patch.  I can pick
it up after the comments get addressed.

Shawn