[PATCH v4 armsoc/drivers/bus+gpio 0/5] Add Moxtet bus and GPIO over Moxtet bus

[PATCH v4 armsoc/drivers/bus+gpio 0/5] Add Moxtet bus and GPIO over Moxtet bus

[Marek Behún]

Hello,

this is the fourth version of patches to support the Moxtet bus and
GPIOs over it. Moxtet is a Turris Mox specific tiny bus over SPI.

I know that merge window is now closed, but I am trying this anyway now, since
Documentation/process/2.Process.rst mentions that even when merge window is
closed, "An occasional exception is made for drivers for previously-unsupported
hardware; if they touch no in-tree code, they cannot cause regressions and
should be safe to add at any time."

These patches apply to current linux/master, linux-gpio/devel
and arm-soc/arm/drivers.

I would appreciate reviews for the changes I made. I removed the Acked-by,
since the changes in drivers/bus/moxtet.c are non-trivial.

Marek

Changes since v3:
  - added module_description file in /sys/bus/moxtet/devices/*/
  - moved debugging into debugfs:
    - removed input_value and output_value debug files from
      /sys/bus/moxtet/devices/*/
    - added input and output debug files to debugfs/moxtet
  - added support for interrupts into moxtet driver:
    Some modules send interrupt via a shared line for all modules.
    In addition to this, they also send interrupt information via the SPI
    shift register, so that the system can distinguish which modules exactly
    sent it and won't have to check all modules.
    This is also needed to fix some bugs when one module sent IRQ and then
    another module sent another IRQ before the first was handled by the system,
    but the handling was already in progress. Since the shared line is
    falling-edge, the second IRQ was never handled.
  - since moxtet driver is now also interrupt controller, device-tree binding
    documentation is also changed

Changes since v2:
  - addressed the issues in device tree documentation pointed by Rob Herring
  - cosmetic changes suggested by Linus Walleij
  - added sysfs ABI documentation for /sys/bus/moxtet/devices attribute files
    as suggested by Linus Walleij

Marek Behún (5):
  bus: Add support for Moxtet bus
  dt-bindings: bus: Document moxtet bus binding
  bus: moxtet: Add sysfs and debugfs documentation
  drivers: gpio: Add support for GPIOs over Moxtet bus
  dt-bindings: gpio: Document GPIOs via Moxtet bus

 Documentation/ABI/testing/debugfs-moxtet      |  23 +
 .../ABI/testing/sysfs-bus-moxtet-devices      |  17 +
 .../devicetree/bindings/bus/moxtet.txt        |  44 +
 .../devicetree/bindings/gpio/gpio-moxtet.txt  |  18 +
 MAINTAINERS                                   |  12 +
 drivers/bus/Kconfig                           |  10 +
 drivers/bus/Makefile                          |   1 +
 drivers/bus/moxtet.c                          | 886 ++++++++++++++++++
 drivers/gpio/Kconfig                          |   9 +
 drivers/gpio/Makefile                         |   1 +
 drivers/gpio/gpio-moxtet.c                    | 179 ++++
 include/dt-bindings/bus/moxtet.h              |  16 +
 include/linux/moxtet.h                        | 109 +++
 13 files changed, 1325 insertions(+)
 create mode 100644 Documentation/ABI/testing/debugfs-moxtet
 create mode 100644 Documentation/ABI/testing/sysfs-bus-moxtet-devices
 create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
 create mode 100644 drivers/bus/moxtet.c
 create mode 100644 drivers/gpio/gpio-moxtet.c
 create mode 100644 include/dt-bindings/bus/moxtet.h
 create mode 100644 include/linux/moxtet.h

-- 
2.19.2

[PATCH v4 armsoc/drivers/bus+gpio 0/5] Add Moxtet bus and GPIO over Moxtet bus

[Marek Behún]

Hello,

this is the fourth version of patches to support the Moxtet bus and
GPIOs over it. Moxtet is a Turris Mox specific tiny bus over SPI.

I know that merge window is now closed, but I am trying this anyway now, since
Documentation/process/2.Process.rst mentions that even when merge window is
closed, "An occasional exception is made for drivers for previously-unsupported
hardware; if they touch no in-tree code, they cannot cause regressions and
should be safe to add at any time."

These patches apply to current linux/master, linux-gpio/devel
and arm-soc/arm/drivers.

I would appreciate reviews for the changes I made. I removed the Acked-by,
since the changes in drivers/bus/moxtet.c are non-trivial.

Marek

Changes since v3:
  - added module_description file in /sys/bus/moxtet/devices/*/
  - moved debugging into debugfs:
    - removed input_value and output_value debug files from
      /sys/bus/moxtet/devices/*/
    - added input and output debug files to debugfs/moxtet
  - added support for interrupts into moxtet driver:
    Some modules send interrupt via a shared line for all modules.
    In addition to this, they also send interrupt information via the SPI
    shift register, so that the system can distinguish which modules exactly
    sent it and won't have to check all modules.
    This is also needed to fix some bugs when one module sent IRQ and then
    another module sent another IRQ before the first was handled by the system,
    but the handling was already in progress. Since the shared line is
    falling-edge, the second IRQ was never handled.
  - since moxtet driver is now also interrupt controller, device-tree binding
    documentation is also changed

Changes since v2:
  - addressed the issues in device tree documentation pointed by Rob Herring
  - cosmetic changes suggested by Linus Walleij
  - added sysfs ABI documentation for /sys/bus/moxtet/devices attribute files
    as suggested by Linus Walleij

Marek Behún (5):
  bus: Add support for Moxtet bus
  dt-bindings: bus: Document moxtet bus binding
  bus: moxtet: Add sysfs and debugfs documentation
  drivers: gpio: Add support for GPIOs over Moxtet bus
  dt-bindings: gpio: Document GPIOs via Moxtet bus

 Documentation/ABI/testing/debugfs-moxtet      |  23 +
 .../ABI/testing/sysfs-bus-moxtet-devices      |  17 +
 .../devicetree/bindings/bus/moxtet.txt        |  44 +
 .../devicetree/bindings/gpio/gpio-moxtet.txt  |  18 +
 MAINTAINERS                                   |  12 +
 drivers/bus/Kconfig                           |  10 +
 drivers/bus/Makefile                          |   1 +
 drivers/bus/moxtet.c                          | 886 ++++++++++++++++++
 drivers/gpio/Kconfig                          |   9 +
 drivers/gpio/Makefile                         |   1 +
 drivers/gpio/gpio-moxtet.c                    | 179 ++++
 include/dt-bindings/bus/moxtet.h              |  16 +
 include/linux/moxtet.h                        | 109 +++
 13 files changed, 1325 insertions(+)
 create mode 100644 Documentation/ABI/testing/debugfs-moxtet
 create mode 100644 Documentation/ABI/testing/sysfs-bus-moxtet-devices
 create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
 create mode 100644 drivers/bus/moxtet.c
 create mode 100644 drivers/gpio/gpio-moxtet.c
 create mode 100644 include/dt-bindings/bus/moxtet.h
 create mode 100644 include/linux/moxtet.h

-- 
2.19.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v4 armsoc/drivers/bus+gpio 1/5] bus: Add support for Moxtet bus

[Marek Behún]

On the Turris Mox router different modules can be connected to the main
CPU board: currently a module with a SFP cage, a module with MiniPCIe
connector, a PCIe pass-through MiniPCIe connector module, a 4-port
switch module, an 8-port switch module, and a 4-port USB3 module.

For example:
  [CPU]-[PCIe-pass-through]-[PCIe]-[8-port switch]-[8-port switch]-[SFP]

Each of this modules has an input and output shift register, and these
are connected via SPI to the CPU board.

Via SPI we are able to discover which modules are connected, in which
order, and we can also read some information about the modules (eg.
their interrupt status), and configure them.
>From each module 8 bits can be read (of which low 4 bits identify the
module) and 8 bits can be written.

For example from the module with a SFP cage we can read the LOS,
TX-FAULT and MOD-DEF0 signals, while we can write TX-DISABLE and
RATE-SELECT signals.

This driver creates a new bus type, called "moxtet". For each Mox module
it finds via SPI, it creates a new device on the moxtet bus so that
drivers can be written for them.

It also implements a virtual interrupt controller for the modules which
send their interrupt status over the SPI shift register. These modules
do this in addition to sending their interrupt status via the shared
interrupt line. When the shared interrupt is triggered, we read from the
shift register and handle IRQs for all devices which are in interrupt.

The topology of how Mox modules are connected can then be read by
listing /sys/bus/moxtet/devices.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
 MAINTAINERS                      |   7 +
 drivers/bus/Kconfig              |  10 +
 drivers/bus/Makefile             |   1 +
 drivers/bus/moxtet.c             | 886 +++++++++++++++++++++++++++++++
 include/dt-bindings/bus/moxtet.h |  16 +
 include/linux/moxtet.h           | 109 ++++
 6 files changed, 1029 insertions(+)
 create mode 100644 drivers/bus/moxtet.c
 create mode 100644 include/dt-bindings/bus/moxtet.h
 create mode 100644 include/linux/moxtet.h

diff --git a/MAINTAINERS b/MAINTAINERS
index a419acaa01c5..d96d36c83bc3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1498,6 +1498,13 @@ F:	drivers/clocksource/timer-atlas7.c
 N:	[^a-z]sirf
 X:	drivers/gnss
 
+ARM/CZ.NIC TURRIS MOX SUPPORT
+M:	Marek Behun <marek.behun@nic.cz>
+W:	http://mox.turris.cz
+S:	Maintained
+F:	include/linux/moxtet.h
+F:	drivers/bus/moxtet.c
+
 ARM/EBSA110 MACHINE SUPPORT
 M:	Russell King <linux@armlinux.org.uk>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 1851112ccc29..6b331061d34b 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -29,6 +29,16 @@ config BRCMSTB_GISB_ARB
 	  arbiter. This driver provides timeout and target abort error handling
 	  and internal bus master decoding.
 
+config MOXTET
+	tristate "CZ.NIC Turris Mox module configuration bus"
+	depends on SPI_MASTER && OF
+	help
+	  Say yes here to add support for the module configuration bus found
+	  on CZ.NIC's Turris Mox. This is needed for the ability to discover
+	  the order in which the modules are connected and to get/set some of
+	  their settings. For example the GPIOs on Mox SFP module are
+	  configured through this bus.
+
 config HISILICON_LPC
 	bool "Support for ISA I/O space on HiSilicon Hip06/7"
 	depends on ARM64 && (ARCH_HISI || COMPILE_TEST)
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index ca300b1914ce..16b43d3468c6 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_ARM_CCI)		+= arm-cci.o
 
 obj-$(CONFIG_HISILICON_LPC)	+= hisi_lpc.o
 obj-$(CONFIG_BRCMSTB_GISB_ARB)	+= brcmstb_gisb.o
+obj-$(CONFIG_MOXTET)		+= moxtet.o
 
 # DPAA2 fsl-mc bus
 obj-$(CONFIG_FSL_MC_BUS)	+= fsl-mc/
diff --git a/drivers/bus/moxtet.c b/drivers/bus/moxtet.c
new file mode 100644
index 000000000000..1ee4570e7e17
--- /dev/null
+++ b/drivers/bus/moxtet.c
@@ -0,0 +1,886 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Turris Mox module configuration bus driver
+ *
+ * Copyright (C) 2019 Marek Behun <marek.behun@nic.cz>
+ */
+
+#include <dt-bindings/bus/moxtet.h>
+#include <linux/bitops.h>
+#include <linux/debugfs.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/moxtet.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/spi/spi.h>
+
+/*
+ * @name:	module name for sysfs
+ * @hwirq_base:	base index for IRQ for this module (-1 if no IRQs)
+ * @nirqs:	how many interrupts does the shift register provide
+ * @desc:	module description for kernel log
+ */
+static const struct {
+	const char *name;
+	int hwirq_base;
+	int nirqs;
+	const char *desc;
+} mox_module_table[] = {
+	/* do not change order of this array! */
+	{ NULL,		 0,			0, NULL },
+	{ "sfp",	-1,			0, "MOX D (SFP cage)" },
+	{ "pci",	MOXTET_IRQ_PCI,		1, "MOX B (Mini-PCIe)" },
+	{ "topaz",	MOXTET_IRQ_TOPAZ,	1, "MOX C (4 port switch)" },
+	{ "peridot",	MOXTET_IRQ_PERIDOT(0),	1, "MOX E (8 port switch)" },
+	{ "usb3",	MOXTET_IRQ_USB3,	2, "MOX F (USB 3.0)" },
+	{ "pci-bridge",	-1,			0, "MOX G (Mini-PCIe bridge)" },
+};
+
+static inline bool mox_module_known(unsigned int id)
+{
+	return id >= TURRIS_MOX_MODULE_FIRST && id <= TURRIS_MOX_MODULE_LAST;
+}
+
+static inline const char *mox_module_name(unsigned int id)
+{
+	if (mox_module_known(id))
+		return mox_module_table[id].name;
+	else
+		return "unknown";
+}
+
+#define DEF_MODULE_ATTR(name, fmt, ...)					\
+static ssize_t								\
+module_##name##_show(struct device *dev, struct device_attribute *a,	\
+		     char *buf)						\
+{									\
+	struct moxtet_device *mdev = to_moxtet_device(dev);		\
+	return sprintf(buf, (fmt), __VA_ARGS__);			\
+}									\
+static DEVICE_ATTR_RO(module_##name)
+
+DEF_MODULE_ATTR(id, "0x%x\n", mdev->id);
+DEF_MODULE_ATTR(name, "%s\n", mox_module_name(mdev->id));
+DEF_MODULE_ATTR(description, "%s\n",
+		mox_module_known(mdev->id) ? mox_module_table[mdev->id].desc
+					   : "");
+
+static struct attribute *moxtet_dev_attrs[] = {
+	&dev_attr_module_id.attr,
+	&dev_attr_module_name.attr,
+	&dev_attr_module_description.attr,
+	NULL,
+};
+
+static const struct attribute_group moxtet_dev_group = {
+	.attrs = moxtet_dev_attrs,
+};
+
+static const struct attribute_group *moxtet_dev_groups[] = {
+	&moxtet_dev_group,
+	NULL,
+};
+
+static int moxtet_match(struct device *dev, struct device_driver *drv)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet_driver *tdrv = to_moxtet_driver(drv);
+	const enum turris_mox_module_id *t;
+
+	if (of_driver_match_device(dev, drv))
+		return 1;
+
+	if (!tdrv->id_table)
+		return 0;
+
+	for (t = tdrv->id_table; *t; ++t)
+		if (*t == mdev->id)
+			return 1;
+
+	return 0;
+}
+
+struct bus_type moxtet_bus_type = {
+	.name		= "moxtet",
+	.dev_groups	= moxtet_dev_groups,
+	.match		= moxtet_match,
+};
+EXPORT_SYMBOL_GPL(moxtet_bus_type);
+
+int __moxtet_register_driver(struct module *owner,
+			     struct moxtet_driver *mdrv)
+{
+	mdrv->driver.owner = owner;
+	mdrv->driver.bus = &moxtet_bus_type;
+	return driver_register(&mdrv->driver);
+}
+EXPORT_SYMBOL_GPL(__moxtet_register_driver);
+
+static int moxtet_dev_check(struct device *dev, void *data)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet_device *new_dev = data;
+
+	if (mdev->moxtet == new_dev->moxtet && mdev->id == new_dev->id &&
+	    mdev->idx == new_dev->idx)
+		return -EBUSY;
+	return 0;
+}
+
+static void moxtet_dev_release(struct device *dev)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+
+	put_device(mdev->moxtet->dev);
+	kfree(mdev);
+}
+
+static struct moxtet_device *
+moxtet_alloc_device(struct moxtet *moxtet)
+{
+	struct moxtet_device *dev;
+
+	if (!get_device(moxtet->dev))
+		return NULL;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev) {
+		put_device(moxtet->dev);
+		return NULL;
+	}
+
+	dev->moxtet = moxtet;
+	dev->dev.parent = moxtet->dev;
+	dev->dev.bus = &moxtet_bus_type;
+	dev->dev.release = moxtet_dev_release;
+
+	device_initialize(&dev->dev);
+
+	return dev;
+}
+
+static int moxtet_add_device(struct moxtet_device *dev)
+{
+	static DEFINE_MUTEX(add_mutex);
+	int ret;
+
+	if (dev->idx >= TURRIS_MOX_MAX_MODULES || dev->id > 0xf)
+		return -EINVAL;
+
+	dev_set_name(&dev->dev, "moxtet-%s.%u", mox_module_name(dev->id),
+		     dev->idx);
+
+	mutex_lock(&add_mutex);
+
+	ret = bus_for_each_dev(&moxtet_bus_type, NULL, dev,
+			       moxtet_dev_check);
+	if (ret)
+		goto done;
+
+	ret = device_add(&dev->dev);
+	if (ret < 0)
+		dev_err(dev->moxtet->dev, "can't add %s, status %d\n",
+			dev_name(dev->moxtet->dev), ret);
+
+done:
+	mutex_unlock(&add_mutex);
+	return ret;
+}
+
+static int __unregister(struct device *dev, void *null)
+{
+	if (dev->of_node) {
+		of_node_clear_flag(dev->of_node, OF_POPULATED);
+		of_node_put(dev->of_node);
+	}
+
+	device_unregister(dev);
+
+	return 0;
+}
+
+static struct moxtet_device *
+of_register_moxtet_device(struct moxtet *moxtet, struct device_node *nc)
+{
+	struct moxtet_device *dev;
+	u32 val;
+	int ret;
+
+	dev = moxtet_alloc_device(moxtet);
+	if (!dev) {
+		dev_err(moxtet->dev,
+			"Moxtet device alloc error for %pOF\n", nc);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ret = of_property_read_u32(nc, "reg", &val);
+	if (ret) {
+		dev_err(moxtet->dev, "%pOF has no valid 'reg' property (%d)\n",
+			nc, ret);
+		goto err_put;
+	}
+
+	dev->idx = val;
+
+	if (dev->idx >= TURRIS_MOX_MAX_MODULES) {
+		dev_err(moxtet->dev, "%pOF Moxtet address 0x%x out of range\n",
+			nc, dev->idx);
+		ret = -EINVAL;
+		goto err_put;
+	}
+
+	dev->id = moxtet->modules[dev->idx];
+
+	if (!dev->id) {
+		dev_err(moxtet->dev, "%pOF Moxtet address 0x%x is empty\n", nc,
+			dev->idx);
+		ret = -ENODEV;
+		goto err_put;
+	}
+
+	of_node_get(nc);
+	dev->dev.of_node = nc;
+
+	ret = moxtet_add_device(dev);
+	if (ret) {
+		dev_err(moxtet->dev,
+			"Moxtet device register error for %pOF\n", nc);
+		of_node_put(nc);
+		goto err_put;
+	}
+
+	return dev;
+
+err_put:
+	put_device(&dev->dev);
+	return ERR_PTR(ret);
+}
+
+static void of_register_moxtet_devices(struct moxtet *moxtet)
+{
+	struct moxtet_device *dev;
+	struct device_node *nc;
+
+	if (!moxtet->dev->of_node)
+		return;
+
+	for_each_available_child_of_node(moxtet->dev->of_node, nc) {
+		if (of_node_test_and_set_flag(nc, OF_POPULATED))
+			continue;
+		dev = of_register_moxtet_device(moxtet, nc);
+		if (IS_ERR(dev)) {
+			dev_warn(moxtet->dev,
+				 "Failed to create Moxtet device for %pOF\n",
+				 nc);
+			of_node_clear_flag(nc, OF_POPULATED);
+		}
+	}
+}
+
+static void
+moxtet_register_devices_from_topology(struct moxtet *moxtet)
+{
+	struct moxtet_device *dev;
+	int i, ret;
+
+	for (i = 0; i < moxtet->count; ++i) {
+		dev = moxtet_alloc_device(moxtet);
+		if (!dev) {
+			dev_err(moxtet->dev, "Moxtet device %u alloc error\n",
+				i);
+			continue;
+		}
+
+		dev->idx = i;
+		dev->id = moxtet->modules[i];
+
+		ret = moxtet_add_device(dev);
+		if (ret && ret != -EBUSY) {
+			put_device(&dev->dev);
+			dev_err(moxtet->dev,
+				"Moxtet device %u register error: %i\n", i,
+				ret);
+		}
+	}
+}
+
+/*
+ * @nsame:	how many modules with same id are already in moxtet->modules
+ */
+static int moxtet_set_irq(struct moxtet *moxtet, int idx, int id, int nsame)
+{
+	int i, first;
+	struct moxtet_irqpos *pos;
+
+	first = mox_module_table[id].hwirq_base +
+		nsame * mox_module_table[id].nirqs;
+
+	if (first + mox_module_table[id].nirqs > MOXTET_NIRQS)
+		return -EINVAL;
+
+	for (i = 0; i < mox_module_table[id].nirqs; ++i) {
+		pos = &moxtet->irq.position[first + i];
+		pos->idx = idx;
+		pos->bit = i;
+		moxtet->irq.exists |= BIT(first + i);
+	}
+
+	return 0;
+}
+
+static int moxtet_find_topology(struct moxtet *moxtet)
+{
+	u8 buf[TURRIS_MOX_MAX_MODULES];
+	int cnts[TURRIS_MOX_MODULE_LAST];
+	int i, ret;
+
+	memset(cnts, 0, sizeof(cnts));
+
+	ret = spi_read(to_spi_device(moxtet->dev), buf, TURRIS_MOX_MAX_MODULES);
+	if (ret < 0)
+		return ret;
+
+	if (buf[0] == TURRIS_MOX_CPU_ID_EMMC) {
+		dev_info(moxtet->dev, "Found MOX A (eMMC CPU) module\n");
+	} else if (buf[0] == TURRIS_MOX_CPU_ID_SD) {
+		dev_info(moxtet->dev, "Found MOX A (CPU) module\n");
+	} else {
+		dev_err(moxtet->dev, "Invalid Turris MOX A CPU module 0x%02x\n",
+			buf[0]);
+		return -ENODEV;
+	}
+
+	moxtet->count = 0;
+
+	for (i = 1; i < TURRIS_MOX_MAX_MODULES; ++i) {
+		int id;
+
+		if (buf[i] == 0xff)
+			break;
+
+		id = buf[i] & 0xf;
+
+		moxtet->modules[i-1] = id;
+		++moxtet->count;
+
+		if (mox_module_known(id)) {
+			dev_info(moxtet->dev, "Found %s module\n",
+				 mox_module_table[id].desc);
+
+			if (moxtet_set_irq(moxtet, i-1, id, cnts[id]++) < 0)
+				dev_err(moxtet->dev,
+					"  Cannot set IRQ for module %s\n",
+					mox_module_table[id].desc);
+		} else {
+			dev_warn(moxtet->dev,
+				 "Unknown Moxtet module found (ID 0x%02x)\n",
+				 id);
+		}
+	}
+
+	return 0;
+}
+
+static int moxtet_spi_read(struct moxtet *moxtet, u8 *buf)
+{
+	struct spi_transfer xfer = {
+		.rx_buf = buf,
+		.tx_buf = moxtet->tx,
+		.len = moxtet->count + 1
+	};
+	int ret;
+
+	mutex_lock(&moxtet->lock);
+
+	ret = spi_sync_transfer(to_spi_device(moxtet->dev), &xfer, 1);
+
+	mutex_unlock(&moxtet->lock);
+
+	return ret;
+}
+
+int moxtet_device_read(struct device *dev)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet *moxtet = mdev->moxtet;
+	u8 buf[TURRIS_MOX_MAX_MODULES];
+	int ret;
+
+	if (mdev->idx >= moxtet->count)
+		return -EINVAL;
+
+	ret = moxtet_spi_read(moxtet, buf);
+	if (ret < 0)
+		return ret;
+
+	return buf[mdev->idx + 1] >> 4;
+}
+EXPORT_SYMBOL_GPL(moxtet_device_read);
+
+int moxtet_device_write(struct device *dev, u8 val)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet *moxtet = mdev->moxtet;
+	int ret;
+
+	if (mdev->idx >= moxtet->count)
+		return -EINVAL;
+
+	mutex_lock(&moxtet->lock);
+
+	moxtet->tx[moxtet->count - mdev->idx] = val;
+
+	ret = spi_write(to_spi_device(moxtet->dev), moxtet->tx,
+			moxtet->count + 1);
+
+	mutex_unlock(&moxtet->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(moxtet_device_write);
+
+int moxtet_device_written(struct device *dev)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet *moxtet = mdev->moxtet;
+
+	if (mdev->idx >= moxtet->count)
+		return -EINVAL;
+
+	return moxtet->tx[moxtet->count - mdev->idx];
+}
+EXPORT_SYMBOL_GPL(moxtet_device_written);
+
+#ifdef CONFIG_DEBUG_FS
+static int moxtet_debug_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+
+	return nonseekable_open(inode, file);
+}
+
+static ssize_t input_read(struct file *file, char __user *buf, size_t len,
+			  loff_t *ppos)
+{
+	struct moxtet *moxtet = file->private_data;
+	u8 bin[TURRIS_MOX_MAX_MODULES];
+	u8 hex[sizeof(buf) * 2 + 1];
+	int ret, n;
+
+	ret = moxtet_spi_read(moxtet, bin);
+	if (ret < 0)
+		return ret;
+
+	n = moxtet->count + 1;
+	bin2hex(hex, bin, n);
+
+	hex[2*n] = '\n';
+
+	return simple_read_from_buffer(buf, len, ppos, hex, 2*n + 1);
+}
+
+static const struct file_operations input_fops = {
+	.owner	= THIS_MODULE,
+	.open	= moxtet_debug_open,
+	.read	= input_read,
+	.llseek	= no_llseek,
+};
+
+static ssize_t output_read(struct file *file, char __user *buf, size_t len,
+			   loff_t *ppos)
+{
+	struct moxtet *moxtet = file->private_data;
+	u8 hex[TURRIS_MOX_MAX_MODULES * 2 + 1];
+	u8 *p = hex;
+	int i;
+
+	mutex_lock(&moxtet->lock);
+
+	for (i = 0; i < moxtet->count; ++i)
+		p = hex_byte_pack(p, moxtet->tx[moxtet->count - i]);
+
+	mutex_unlock(&moxtet->lock);
+
+	*p++ = '\n';
+
+	return simple_read_from_buffer(buf, len, ppos, hex, p - hex);
+}
+
+static ssize_t output_write(struct file *file, const char __user *buf,
+			    size_t len, loff_t *ppos)
+{
+	struct moxtet *moxtet = file->private_data;
+	u8 bin[TURRIS_MOX_MAX_MODULES];
+	u8 hex[sizeof(bin) * 2 + 1];
+	size_t res;
+	loff_t dummy = 0;
+	int err, i;
+
+	if (len > 2 * moxtet->count + 1 || len < 2 * moxtet->count)
+		return -EINVAL;
+
+	res = simple_write_to_buffer(hex, sizeof(hex), &dummy, buf, len);
+	if (res < 0)
+		return res;
+
+	if (len % 2 == 1 && hex[len - 1] != '\n')
+		return -EINVAL;
+
+	err = hex2bin(bin, hex, moxtet->count);
+	if (err < 0)
+		return -EINVAL;
+
+	mutex_lock(&moxtet->lock);
+
+	for (i = 0; i < moxtet->count; ++i)
+		moxtet->tx[moxtet->count - i] = bin[i];
+
+	err = spi_write(to_spi_device(moxtet->dev), moxtet->tx,
+			moxtet->count + 1);
+
+	mutex_unlock(&moxtet->lock);
+
+	return err < 0 ? err : len;
+}
+
+static const struct file_operations output_fops = {
+	.owner	= THIS_MODULE,
+	.open	= moxtet_debug_open,
+	.read	= output_read,
+	.write	= output_write,
+	.llseek	= no_llseek,
+};
+
+static int moxtet_register_debugfs(struct moxtet *moxtet)
+{
+	struct dentry *root, *entry;
+
+	root = debugfs_create_dir("moxtet", NULL);
+
+	if (IS_ERR(root))
+		return PTR_ERR(root);
+
+	entry = debugfs_create_file_unsafe("input", 0444, root, moxtet,
+					   &input_fops);
+	if (IS_ERR(entry))
+		goto err_remove;
+
+	entry = debugfs_create_file_unsafe("output", 0644, root, moxtet,
+					   &output_fops);
+	if (IS_ERR(entry))
+		goto err_remove;
+
+	moxtet->debugfs_root = root;
+
+	return 0;
+err_remove:
+	debugfs_remove_recursive(root);
+	return PTR_ERR(entry);
+}
+
+static void moxtet_unregister_debugfs(struct moxtet *moxtet)
+{
+	debugfs_remove_recursive(moxtet->debugfs_root);
+}
+#else
+static inline int moxtet_register_debugfs(struct moxtet *moxtet)
+{
+	return 0;
+}
+
+static inline void moxtet_unregister_debugfs(struct moxtet *moxtet)
+{
+}
+#endif
+
+static int moxtet_irq_domain_map(struct irq_domain *d, unsigned int irq,
+				 irq_hw_number_t hw)
+{
+	struct moxtet *moxtet = d->host_data;
+
+	if (hw >= MOXTET_NIRQS || !(moxtet->irq.exists & BIT(hw))) {
+		dev_err(moxtet->dev, "Invalid hw irq number\n");
+		return -EINVAL;
+	}
+
+	irq_set_chip_data(irq, d->host_data);
+	irq_set_chip_and_handler(irq, &moxtet->irq.chip, handle_level_irq);
+
+	return 0;
+}
+
+static int moxtet_irq_domain_xlate(struct irq_domain *d,
+				   struct device_node *ctrlr,
+				   const u32 *intspec, unsigned int intsize,
+				   unsigned long *out_hwirq,
+				   unsigned int *out_type)
+{
+	struct moxtet *moxtet = d->host_data;
+	int irq;
+
+	if (WARN_ON(intsize < 1))
+		return -EINVAL;
+
+	irq = intspec[0];
+
+	if (irq >= MOXTET_NIRQS || !(moxtet->irq.exists & BIT(irq)))
+		return -EINVAL;
+
+	*out_hwirq = irq;
+	*out_type = IRQ_TYPE_NONE;
+	return 0;
+}
+
+static const struct irq_domain_ops moxtet_irq_domain = {
+	.map = moxtet_irq_domain_map,
+	.xlate = moxtet_irq_domain_xlate,
+};
+
+static void moxtet_irq_mask(struct irq_data *d)
+{
+	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
+
+	moxtet->irq.masked |= BIT(d->hwirq);
+}
+
+static void moxtet_irq_unmask(struct irq_data *d)
+{
+	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
+
+	moxtet->irq.masked &= ~BIT(d->hwirq);
+}
+
+static void moxtet_irq_print_chip(struct irq_data *d, struct seq_file *p)
+{
+	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
+	struct moxtet_irqpos *pos = &moxtet->irq.position[d->hwirq];
+	int id;
+
+	id = moxtet->modules[pos->idx];
+
+	seq_printf(p, " moxtet-%s.%i#%i", mox_module_name(id), pos->idx,
+		   pos->bit);
+}
+
+static const struct irq_chip moxtet_irq_chip = {
+	.name			= "moxtet",
+	.irq_mask		= moxtet_irq_mask,
+	.irq_unmask		= moxtet_irq_unmask,
+	.irq_print_chip		= moxtet_irq_print_chip,
+};
+
+static int moxtet_irq_read(struct moxtet *moxtet, unsigned long *map)
+{
+	struct moxtet_irqpos *pos = moxtet->irq.position;
+	u8 buf[TURRIS_MOX_MAX_MODULES];
+	int i, ret;
+
+	ret = moxtet_spi_read(moxtet, buf);
+	if (ret < 0)
+		return ret;
+
+	*map = 0;
+
+	for_each_set_bit(i, &moxtet->irq.exists, MOXTET_NIRQS) {
+		if (!(buf[pos[i].idx + 1] & BIT(4 + pos[i].bit)))
+			set_bit(i, map);
+	}
+
+	return 0;
+}
+
+static irqreturn_t moxtet_irq_thread_fn(int irq, void *data)
+{
+	struct moxtet *moxtet = data;
+	unsigned long set;
+	int nhandled = 0, i, sub_irq, ret;
+
+	ret = moxtet_irq_read(moxtet, &set);
+	if (ret < 0)
+		goto out;
+
+	set &= ~moxtet->irq.masked;
+
+	do {
+		for_each_set_bit(i, &set, MOXTET_NIRQS) {
+			sub_irq = irq_find_mapping(moxtet->irq.domain, i);
+			handle_nested_irq(sub_irq);
+			dev_dbg(moxtet->dev, "%i irq\n", i);
+			++nhandled;
+		}
+
+		ret = moxtet_irq_read(moxtet, &set);
+		if (ret < 0)
+			goto out;
+
+		set &= ~moxtet->irq.masked;
+	} while (set);
+
+out:
+	return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
+}
+
+static void moxtet_irq_free(struct moxtet *moxtet)
+{
+	int i, irq;
+
+	for (i = 0; i < MOXTET_NIRQS; ++i) {
+		if (moxtet->irq.exists & BIT(i)) {
+			irq = irq_find_mapping(moxtet->irq.domain, i);
+			irq_dispose_mapping(irq);
+		}
+	}
+
+	irq_domain_remove(moxtet->irq.domain);
+}
+
+static int moxtet_irq_setup(struct moxtet *moxtet)
+{
+	int i, ret;
+
+	moxtet->irq.domain = irq_domain_add_simple(moxtet->dev->of_node,
+						   MOXTET_NIRQS, 0,
+						   &moxtet_irq_domain, moxtet);
+	if (moxtet->irq.domain == NULL) {
+		dev_err(moxtet->dev, "Could not add IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < MOXTET_NIRQS; ++i)
+		if (moxtet->irq.exists & BIT(i))
+			irq_create_mapping(moxtet->irq.domain, i);
+
+	moxtet->irq.chip = moxtet_irq_chip;
+	moxtet->irq.masked = ~0;
+
+	ret = request_threaded_irq(moxtet->dev_irq, NULL, moxtet_irq_thread_fn,
+				   IRQF_ONESHOT, "moxtet", moxtet);
+	if (ret < 0)
+		goto err_free;
+
+	return 0;
+
+err_free:
+	moxtet_irq_free(moxtet);
+	return ret;
+}
+
+static int moxtet_probe(struct spi_device *spi)
+{
+	struct moxtet *moxtet;
+	int ret;
+
+	ret = spi_setup(spi);
+	if (ret < 0)
+		return ret;
+
+	moxtet = devm_kzalloc(&spi->dev, sizeof(struct moxtet),
+			      GFP_KERNEL);
+	if (!moxtet)
+		return -ENOMEM;
+
+	moxtet->dev = &spi->dev;
+	spi_set_drvdata(spi, moxtet);
+
+	mutex_init(&moxtet->lock);
+
+	moxtet->dev_irq = of_irq_get(moxtet->dev->of_node, 0);
+	if (moxtet->dev_irq == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	if (moxtet->dev_irq <= 0) {
+		dev_err(moxtet->dev, "No IRQ resource found\n");
+		return -ENXIO;
+	}
+
+	ret = moxtet_find_topology(moxtet);
+	if (ret < 0)
+		return ret;
+
+	if (moxtet->irq.exists) {
+		ret = moxtet_irq_setup(moxtet);
+		if (ret < 0)
+			return ret;
+	}
+
+	of_register_moxtet_devices(moxtet);
+	moxtet_register_devices_from_topology(moxtet);
+
+	ret = moxtet_register_debugfs(moxtet);
+	if (ret < 0)
+		dev_warn(moxtet->dev, "Failed creating debugfs entries: %i\n",
+			 ret);
+
+	return 0;
+}
+
+static int moxtet_remove(struct spi_device *spi)
+{
+	struct moxtet *moxtet = spi_get_drvdata(spi);
+	int dummy;
+
+	free_irq(moxtet->dev_irq, moxtet);
+
+	moxtet_irq_free(moxtet);
+
+	moxtet_unregister_debugfs(moxtet);
+
+	dummy = device_for_each_child(moxtet->dev, NULL, __unregister);
+
+	mutex_destroy(&moxtet->lock);
+
+	return 0;
+}
+
+static const struct of_device_id moxtet_dt_ids[] = {
+	{ .compatible = "cznic,moxtet" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, moxtet_dt_ids);
+
+static struct spi_driver moxtet_spi_driver = {
+	.driver = {
+		.name		= "moxtet",
+		.of_match_table = moxtet_dt_ids,
+	},
+	.probe		= moxtet_probe,
+	.remove		= moxtet_remove,
+};
+
+static int __init moxtet_init(void)
+{
+	int ret;
+
+	ret = bus_register(&moxtet_bus_type);
+	if (ret < 0) {
+		pr_err("moxtet bus registration failed: %d\n", ret);
+		goto error;
+	}
+
+	ret = spi_register_driver(&moxtet_spi_driver);
+	if (ret < 0) {
+		pr_err("moxtet spi driver registration failed: %d\n", ret);
+		goto error_bus;
+	}
+
+	return 0;
+
+error_bus:
+	bus_unregister(&moxtet_bus_type);
+error:
+	return ret;
+}
+postcore_initcall_sync(moxtet_init);
+
+static void __exit moxtet_exit(void)
+{
+	spi_unregister_driver(&moxtet_spi_driver);
+	bus_unregister(&moxtet_bus_type);
+}
+module_exit(moxtet_exit);
+
+MODULE_AUTHOR("Marek Behun <marek.behun@nic.cz>");
+MODULE_DESCRIPTION("CZ.NIC's Turris Mox module configuration bus");
+MODULE_LICENSE("GPL v2");
diff --git a/include/dt-bindings/bus/moxtet.h b/include/dt-bindings/bus/moxtet.h
new file mode 100644
index 000000000000..dc9345440ebe
--- /dev/null
+++ b/include/dt-bindings/bus/moxtet.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Constant for device tree bindings for Turris Mox module configuration bus
+ *
+ * Copyright (C) 2019 Marek Behun <marek.behun@nic.cz>
+ */
+
+#ifndef _DT_BINDINGS_BUS_MOXTET_H
+#define _DT_BINDINGS_BUS_MOXTET_H
+
+#define MOXTET_IRQ_PCI		0
+#define MOXTET_IRQ_USB3		4
+#define MOXTET_IRQ_PERIDOT(n)	(8 + (n))
+#define MOXTET_IRQ_TOPAZ	12
+
+#endif /* _DT_BINDINGS_BUS_MOXTET_H */
diff --git a/include/linux/moxtet.h b/include/linux/moxtet.h
new file mode 100644
index 000000000000..490db6886dcc
--- /dev/null
+++ b/include/linux/moxtet.h
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Turris Mox module configuration bus driver
+ *
+ * Copyright (C) 2019 Marek Behun <marek.behun@nic.cz>
+ */
+
+#ifndef __LINUX_MOXTET_H
+#define __LINUX_MOXTET_H
+
+#include <linux/device.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mutex.h>
+
+#define TURRIS_MOX_MAX_MODULES	10
+
+enum turris_mox_cpu_module_id {
+	TURRIS_MOX_CPU_ID_EMMC	= 0x00,
+	TURRIS_MOX_CPU_ID_SD	= 0x10,
+};
+
+enum turris_mox_module_id {
+	TURRIS_MOX_MODULE_FIRST		= 0x01,
+
+	TURRIS_MOX_MODULE_SFP		= 0x01,
+	TURRIS_MOX_MODULE_PCI		= 0x02,
+	TURRIS_MOX_MODULE_TOPAZ		= 0x03,
+	TURRIS_MOX_MODULE_PERIDOT	= 0x04,
+	TURRIS_MOX_MODULE_USB3		= 0x05,
+	TURRIS_MOX_MODULE_PCI_BRIDGE	= 0x06,
+
+	TURRIS_MOX_MODULE_LAST		= 0x06,
+};
+
+#define MOXTET_NIRQS	16
+
+extern struct bus_type moxtet_type;
+
+struct moxtet {
+	struct device			*dev;
+	struct mutex			lock;
+	u8				modules[TURRIS_MOX_MAX_MODULES];
+	int				count;
+	u8				tx[TURRIS_MOX_MAX_MODULES];
+	int				dev_irq;
+	struct {
+		struct irq_domain	*domain;
+		struct irq_chip		chip;
+		unsigned long		masked, exists;
+		struct moxtet_irqpos {
+					u8 idx;
+					u8 bit;
+		} position[MOXTET_NIRQS];
+	} irq;
+#ifdef CONFIG_DEBUG_FS
+	struct dentry			*debugfs_root;
+#endif
+};
+
+struct moxtet_driver {
+	const enum turris_mox_module_id	*id_table;
+	struct device_driver		driver;
+};
+
+static inline struct moxtet_driver *
+to_moxtet_driver(struct device_driver *drv)
+{
+	if (!drv)
+		return NULL;
+	return container_of(drv, struct moxtet_driver, driver);
+}
+
+extern int __moxtet_register_driver(struct module *owner,
+				    struct moxtet_driver *mdrv);
+
+static inline void moxtet_unregister_driver(struct moxtet_driver *mdrv)
+{
+	if (mdrv)
+		driver_unregister(&mdrv->driver);
+}
+
+#define moxtet_register_driver(driver) \
+	__moxtet_register_driver(THIS_MODULE, driver)
+
+#define module_moxtet_driver(__moxtet_driver) \
+	module_driver(__moxtet_driver, moxtet_register_driver, \
+			moxtet_unregister_driver)
+
+struct moxtet_device {
+	struct device			dev;
+	struct moxtet			*moxtet;
+	enum turris_mox_module_id	id;
+	unsigned int			idx;
+};
+
+extern int moxtet_device_read(struct device *dev);
+extern int moxtet_device_write(struct device *dev, u8 val);
+extern int moxtet_device_written(struct device *dev);
+
+static inline struct moxtet_device *
+to_moxtet_device(struct device *dev)
+{
+	if (!dev)
+		return NULL;
+	return container_of(dev, struct moxtet_device, dev);
+}
+
+#endif /* __LINUX_MOXTET_H */
-- 
2.19.2

[PATCH v4 armsoc/drivers/bus+gpio 1/5] bus: Add support for Moxtet bus

[Marek Behún]

On the Turris Mox router different modules can be connected to the main
CPU board: currently a module with a SFP cage, a module with MiniPCIe
connector, a PCIe pass-through MiniPCIe connector module, a 4-port
switch module, an 8-port switch module, and a 4-port USB3 module.

For example:
  [CPU]-[PCIe-pass-through]-[PCIe]-[8-port switch]-[8-port switch]-[SFP]

Each of this modules has an input and output shift register, and these
are connected via SPI to the CPU board.

Via SPI we are able to discover which modules are connected, in which
order, and we can also read some information about the modules (eg.
their interrupt status), and configure them.
From each module 8 bits can be read (of which low 4 bits identify the
module) and 8 bits can be written.

For example from the module with a SFP cage we can read the LOS,
TX-FAULT and MOD-DEF0 signals, while we can write TX-DISABLE and
RATE-SELECT signals.

This driver creates a new bus type, called "moxtet". For each Mox module
it finds via SPI, it creates a new device on the moxtet bus so that
drivers can be written for them.

It also implements a virtual interrupt controller for the modules which
send their interrupt status over the SPI shift register. These modules
do this in addition to sending their interrupt status via the shared
interrupt line. When the shared interrupt is triggered, we read from the
shift register and handle IRQs for all devices which are in interrupt.

The topology of how Mox modules are connected can then be read by
listing /sys/bus/moxtet/devices.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
 MAINTAINERS                      |   7 +
 drivers/bus/Kconfig              |  10 +
 drivers/bus/Makefile             |   1 +
 drivers/bus/moxtet.c             | 886 +++++++++++++++++++++++++++++++
 include/dt-bindings/bus/moxtet.h |  16 +
 include/linux/moxtet.h           | 109 ++++
 6 files changed, 1029 insertions(+)
 create mode 100644 drivers/bus/moxtet.c
 create mode 100644 include/dt-bindings/bus/moxtet.h
 create mode 100644 include/linux/moxtet.h

diff --git a/MAINTAINERS b/MAINTAINERS
index a419acaa01c5..d96d36c83bc3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1498,6 +1498,13 @@ F:	drivers/clocksource/timer-atlas7.c
 N:	[^a-z]sirf
 X:	drivers/gnss
 
+ARM/CZ.NIC TURRIS MOX SUPPORT
+M:	Marek Behun <marek.behun@nic.cz>
+W:	http://mox.turris.cz
+S:	Maintained
+F:	include/linux/moxtet.h
+F:	drivers/bus/moxtet.c
+
 ARM/EBSA110 MACHINE SUPPORT
 M:	Russell King <linux@armlinux.org.uk>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 1851112ccc29..6b331061d34b 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -29,6 +29,16 @@ config BRCMSTB_GISB_ARB
 	  arbiter. This driver provides timeout and target abort error handling
 	  and internal bus master decoding.
 
+config MOXTET
+	tristate "CZ.NIC Turris Mox module configuration bus"
+	depends on SPI_MASTER && OF
+	help
+	  Say yes here to add support for the module configuration bus found
+	  on CZ.NIC's Turris Mox. This is needed for the ability to discover
+	  the order in which the modules are connected and to get/set some of
+	  their settings. For example the GPIOs on Mox SFP module are
+	  configured through this bus.
+
 config HISILICON_LPC
 	bool "Support for ISA I/O space on HiSilicon Hip06/7"
 	depends on ARM64 && (ARCH_HISI || COMPILE_TEST)
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index ca300b1914ce..16b43d3468c6 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_ARM_CCI)		+= arm-cci.o
 
 obj-$(CONFIG_HISILICON_LPC)	+= hisi_lpc.o
 obj-$(CONFIG_BRCMSTB_GISB_ARB)	+= brcmstb_gisb.o
+obj-$(CONFIG_MOXTET)		+= moxtet.o
 
 # DPAA2 fsl-mc bus
 obj-$(CONFIG_FSL_MC_BUS)	+= fsl-mc/
diff --git a/drivers/bus/moxtet.c b/drivers/bus/moxtet.c
new file mode 100644
index 000000000000..1ee4570e7e17
--- /dev/null
+++ b/drivers/bus/moxtet.c
@@ -0,0 +1,886 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Turris Mox module configuration bus driver
+ *
+ * Copyright (C) 2019 Marek Behun <marek.behun@nic.cz>
+ */
+
+#include <dt-bindings/bus/moxtet.h>
+#include <linux/bitops.h>
+#include <linux/debugfs.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/moxtet.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/spi/spi.h>
+
+/*
+ * @name:	module name for sysfs
+ * @hwirq_base:	base index for IRQ for this module (-1 if no IRQs)
+ * @nirqs:	how many interrupts does the shift register provide
+ * @desc:	module description for kernel log
+ */
+static const struct {
+	const char *name;
+	int hwirq_base;
+	int nirqs;
+	const char *desc;
+} mox_module_table[] = {
+	/* do not change order of this array! */
+	{ NULL,		 0,			0, NULL },
+	{ "sfp",	-1,			0, "MOX D (SFP cage)" },
+	{ "pci",	MOXTET_IRQ_PCI,		1, "MOX B (Mini-PCIe)" },
+	{ "topaz",	MOXTET_IRQ_TOPAZ,	1, "MOX C (4 port switch)" },
+	{ "peridot",	MOXTET_IRQ_PERIDOT(0),	1, "MOX E (8 port switch)" },
+	{ "usb3",	MOXTET_IRQ_USB3,	2, "MOX F (USB 3.0)" },
+	{ "pci-bridge",	-1,			0, "MOX G (Mini-PCIe bridge)" },
+};
+
+static inline bool mox_module_known(unsigned int id)
+{
+	return id >= TURRIS_MOX_MODULE_FIRST && id <= TURRIS_MOX_MODULE_LAST;
+}
+
+static inline const char *mox_module_name(unsigned int id)
+{
+	if (mox_module_known(id))
+		return mox_module_table[id].name;
+	else
+		return "unknown";
+}
+
+#define DEF_MODULE_ATTR(name, fmt, ...)					\
+static ssize_t								\
+module_##name##_show(struct device *dev, struct device_attribute *a,	\
+		     char *buf)						\
+{									\
+	struct moxtet_device *mdev = to_moxtet_device(dev);		\
+	return sprintf(buf, (fmt), __VA_ARGS__);			\
+}									\
+static DEVICE_ATTR_RO(module_##name)
+
+DEF_MODULE_ATTR(id, "0x%x\n", mdev->id);
+DEF_MODULE_ATTR(name, "%s\n", mox_module_name(mdev->id));
+DEF_MODULE_ATTR(description, "%s\n",
+		mox_module_known(mdev->id) ? mox_module_table[mdev->id].desc
+					   : "");
+
+static struct attribute *moxtet_dev_attrs[] = {
+	&dev_attr_module_id.attr,
+	&dev_attr_module_name.attr,
+	&dev_attr_module_description.attr,
+	NULL,
+};
+
+static const struct attribute_group moxtet_dev_group = {
+	.attrs = moxtet_dev_attrs,
+};
+
+static const struct attribute_group *moxtet_dev_groups[] = {
+	&moxtet_dev_group,
+	NULL,
+};
+
+static int moxtet_match(struct device *dev, struct device_driver *drv)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet_driver *tdrv = to_moxtet_driver(drv);
+	const enum turris_mox_module_id *t;
+
+	if (of_driver_match_device(dev, drv))
+		return 1;
+
+	if (!tdrv->id_table)
+		return 0;
+
+	for (t = tdrv->id_table; *t; ++t)
+		if (*t == mdev->id)
+			return 1;
+
+	return 0;
+}
+
+struct bus_type moxtet_bus_type = {
+	.name		= "moxtet",
+	.dev_groups	= moxtet_dev_groups,
+	.match		= moxtet_match,
+};
+EXPORT_SYMBOL_GPL(moxtet_bus_type);
+
+int __moxtet_register_driver(struct module *owner,
+			     struct moxtet_driver *mdrv)
+{
+	mdrv->driver.owner = owner;
+	mdrv->driver.bus = &moxtet_bus_type;
+	return driver_register(&mdrv->driver);
+}
+EXPORT_SYMBOL_GPL(__moxtet_register_driver);
+
+static int moxtet_dev_check(struct device *dev, void *data)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet_device *new_dev = data;
+
+	if (mdev->moxtet == new_dev->moxtet && mdev->id == new_dev->id &&
+	    mdev->idx == new_dev->idx)
+		return -EBUSY;
+	return 0;
+}
+
+static void moxtet_dev_release(struct device *dev)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+
+	put_device(mdev->moxtet->dev);
+	kfree(mdev);
+}
+
+static struct moxtet_device *
+moxtet_alloc_device(struct moxtet *moxtet)
+{
+	struct moxtet_device *dev;
+
+	if (!get_device(moxtet->dev))
+		return NULL;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev) {
+		put_device(moxtet->dev);
+		return NULL;
+	}
+
+	dev->moxtet = moxtet;
+	dev->dev.parent = moxtet->dev;
+	dev->dev.bus = &moxtet_bus_type;
+	dev->dev.release = moxtet_dev_release;
+
+	device_initialize(&dev->dev);
+
+	return dev;
+}
+
+static int moxtet_add_device(struct moxtet_device *dev)
+{
+	static DEFINE_MUTEX(add_mutex);
+	int ret;
+
+	if (dev->idx >= TURRIS_MOX_MAX_MODULES || dev->id > 0xf)
+		return -EINVAL;
+
+	dev_set_name(&dev->dev, "moxtet-%s.%u", mox_module_name(dev->id),
+		     dev->idx);
+
+	mutex_lock(&add_mutex);
+
+	ret = bus_for_each_dev(&moxtet_bus_type, NULL, dev,
+			       moxtet_dev_check);
+	if (ret)
+		goto done;
+
+	ret = device_add(&dev->dev);
+	if (ret < 0)
+		dev_err(dev->moxtet->dev, "can't add %s, status %d\n",
+			dev_name(dev->moxtet->dev), ret);
+
+done:
+	mutex_unlock(&add_mutex);
+	return ret;
+}
+
+static int __unregister(struct device *dev, void *null)
+{
+	if (dev->of_node) {
+		of_node_clear_flag(dev->of_node, OF_POPULATED);
+		of_node_put(dev->of_node);
+	}
+
+	device_unregister(dev);
+
+	return 0;
+}
+
+static struct moxtet_device *
+of_register_moxtet_device(struct moxtet *moxtet, struct device_node *nc)
+{
+	struct moxtet_device *dev;
+	u32 val;
+	int ret;
+
+	dev = moxtet_alloc_device(moxtet);
+	if (!dev) {
+		dev_err(moxtet->dev,
+			"Moxtet device alloc error for %pOF\n", nc);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ret = of_property_read_u32(nc, "reg", &val);
+	if (ret) {
+		dev_err(moxtet->dev, "%pOF has no valid 'reg' property (%d)\n",
+			nc, ret);
+		goto err_put;
+	}
+
+	dev->idx = val;
+
+	if (dev->idx >= TURRIS_MOX_MAX_MODULES) {
+		dev_err(moxtet->dev, "%pOF Moxtet address 0x%x out of range\n",
+			nc, dev->idx);
+		ret = -EINVAL;
+		goto err_put;
+	}
+
+	dev->id = moxtet->modules[dev->idx];
+
+	if (!dev->id) {
+		dev_err(moxtet->dev, "%pOF Moxtet address 0x%x is empty\n", nc,
+			dev->idx);
+		ret = -ENODEV;
+		goto err_put;
+	}
+
+	of_node_get(nc);
+	dev->dev.of_node = nc;
+
+	ret = moxtet_add_device(dev);
+	if (ret) {
+		dev_err(moxtet->dev,
+			"Moxtet device register error for %pOF\n", nc);
+		of_node_put(nc);
+		goto err_put;
+	}
+
+	return dev;
+
+err_put:
+	put_device(&dev->dev);
+	return ERR_PTR(ret);
+}
+
+static void of_register_moxtet_devices(struct moxtet *moxtet)
+{
+	struct moxtet_device *dev;
+	struct device_node *nc;
+
+	if (!moxtet->dev->of_node)
+		return;
+
+	for_each_available_child_of_node(moxtet->dev->of_node, nc) {
+		if (of_node_test_and_set_flag(nc, OF_POPULATED))
+			continue;
+		dev = of_register_moxtet_device(moxtet, nc);
+		if (IS_ERR(dev)) {
+			dev_warn(moxtet->dev,
+				 "Failed to create Moxtet device for %pOF\n",
+				 nc);
+			of_node_clear_flag(nc, OF_POPULATED);
+		}
+	}
+}
+
+static void
+moxtet_register_devices_from_topology(struct moxtet *moxtet)
+{
+	struct moxtet_device *dev;
+	int i, ret;
+
+	for (i = 0; i < moxtet->count; ++i) {
+		dev = moxtet_alloc_device(moxtet);
+		if (!dev) {
+			dev_err(moxtet->dev, "Moxtet device %u alloc error\n",
+				i);
+			continue;
+		}
+
+		dev->idx = i;
+		dev->id = moxtet->modules[i];
+
+		ret = moxtet_add_device(dev);
+		if (ret && ret != -EBUSY) {
+			put_device(&dev->dev);
+			dev_err(moxtet->dev,
+				"Moxtet device %u register error: %i\n", i,
+				ret);
+		}
+	}
+}
+
+/*
+ * @nsame:	how many modules with same id are already in moxtet->modules
+ */
+static int moxtet_set_irq(struct moxtet *moxtet, int idx, int id, int nsame)
+{
+	int i, first;
+	struct moxtet_irqpos *pos;
+
+	first = mox_module_table[id].hwirq_base +
+		nsame * mox_module_table[id].nirqs;
+
+	if (first + mox_module_table[id].nirqs > MOXTET_NIRQS)
+		return -EINVAL;
+
+	for (i = 0; i < mox_module_table[id].nirqs; ++i) {
+		pos = &moxtet->irq.position[first + i];
+		pos->idx = idx;
+		pos->bit = i;
+		moxtet->irq.exists |= BIT(first + i);
+	}
+
+	return 0;
+}
+
+static int moxtet_find_topology(struct moxtet *moxtet)
+{
+	u8 buf[TURRIS_MOX_MAX_MODULES];
+	int cnts[TURRIS_MOX_MODULE_LAST];
+	int i, ret;
+
+	memset(cnts, 0, sizeof(cnts));
+
+	ret = spi_read(to_spi_device(moxtet->dev), buf, TURRIS_MOX_MAX_MODULES);
+	if (ret < 0)
+		return ret;
+
+	if (buf[0] == TURRIS_MOX_CPU_ID_EMMC) {
+		dev_info(moxtet->dev, "Found MOX A (eMMC CPU) module\n");
+	} else if (buf[0] == TURRIS_MOX_CPU_ID_SD) {
+		dev_info(moxtet->dev, "Found MOX A (CPU) module\n");
+	} else {
+		dev_err(moxtet->dev, "Invalid Turris MOX A CPU module 0x%02x\n",
+			buf[0]);
+		return -ENODEV;
+	}
+
+	moxtet->count = 0;
+
+	for (i = 1; i < TURRIS_MOX_MAX_MODULES; ++i) {
+		int id;
+
+		if (buf[i] == 0xff)
+			break;
+
+		id = buf[i] & 0xf;
+
+		moxtet->modules[i-1] = id;
+		++moxtet->count;
+
+		if (mox_module_known(id)) {
+			dev_info(moxtet->dev, "Found %s module\n",
+				 mox_module_table[id].desc);
+
+			if (moxtet_set_irq(moxtet, i-1, id, cnts[id]++) < 0)
+				dev_err(moxtet->dev,
+					"  Cannot set IRQ for module %s\n",
+					mox_module_table[id].desc);
+		} else {
+			dev_warn(moxtet->dev,
+				 "Unknown Moxtet module found (ID 0x%02x)\n",
+				 id);
+		}
+	}
+
+	return 0;
+}
+
+static int moxtet_spi_read(struct moxtet *moxtet, u8 *buf)
+{
+	struct spi_transfer xfer = {
+		.rx_buf = buf,
+		.tx_buf = moxtet->tx,
+		.len = moxtet->count + 1
+	};
+	int ret;
+
+	mutex_lock(&moxtet->lock);
+
+	ret = spi_sync_transfer(to_spi_device(moxtet->dev), &xfer, 1);
+
+	mutex_unlock(&moxtet->lock);
+
+	return ret;
+}
+
+int moxtet_device_read(struct device *dev)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet *moxtet = mdev->moxtet;
+	u8 buf[TURRIS_MOX_MAX_MODULES];
+	int ret;
+
+	if (mdev->idx >= moxtet->count)
+		return -EINVAL;
+
+	ret = moxtet_spi_read(moxtet, buf);
+	if (ret < 0)
+		return ret;
+
+	return buf[mdev->idx + 1] >> 4;
+}
+EXPORT_SYMBOL_GPL(moxtet_device_read);
+
+int moxtet_device_write(struct device *dev, u8 val)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet *moxtet = mdev->moxtet;
+	int ret;
+
+	if (mdev->idx >= moxtet->count)
+		return -EINVAL;
+
+	mutex_lock(&moxtet->lock);
+
+	moxtet->tx[moxtet->count - mdev->idx] = val;
+
+	ret = spi_write(to_spi_device(moxtet->dev), moxtet->tx,
+			moxtet->count + 1);
+
+	mutex_unlock(&moxtet->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(moxtet_device_write);
+
+int moxtet_device_written(struct device *dev)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet *moxtet = mdev->moxtet;
+
+	if (mdev->idx >= moxtet->count)
+		return -EINVAL;
+
+	return moxtet->tx[moxtet->count - mdev->idx];
+}
+EXPORT_SYMBOL_GPL(moxtet_device_written);
+
+#ifdef CONFIG_DEBUG_FS
+static int moxtet_debug_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+
+	return nonseekable_open(inode, file);
+}
+
+static ssize_t input_read(struct file *file, char __user *buf, size_t len,
+			  loff_t *ppos)
+{
+	struct moxtet *moxtet = file->private_data;
+	u8 bin[TURRIS_MOX_MAX_MODULES];
+	u8 hex[sizeof(buf) * 2 + 1];
+	int ret, n;
+
+	ret = moxtet_spi_read(moxtet, bin);
+	if (ret < 0)
+		return ret;
+
+	n = moxtet->count + 1;
+	bin2hex(hex, bin, n);
+
+	hex[2*n] = '\n';
+
+	return simple_read_from_buffer(buf, len, ppos, hex, 2*n + 1);
+}
+
+static const struct file_operations input_fops = {
+	.owner	= THIS_MODULE,
+	.open	= moxtet_debug_open,
+	.read	= input_read,
+	.llseek	= no_llseek,
+};
+
+static ssize_t output_read(struct file *file, char __user *buf, size_t len,
+			   loff_t *ppos)
+{
+	struct moxtet *moxtet = file->private_data;
+	u8 hex[TURRIS_MOX_MAX_MODULES * 2 + 1];
+	u8 *p = hex;
+	int i;
+
+	mutex_lock(&moxtet->lock);
+
+	for (i = 0; i < moxtet->count; ++i)
+		p = hex_byte_pack(p, moxtet->tx[moxtet->count - i]);
+
+	mutex_unlock(&moxtet->lock);
+
+	*p++ = '\n';
+
+	return simple_read_from_buffer(buf, len, ppos, hex, p - hex);
+}
+
+static ssize_t output_write(struct file *file, const char __user *buf,
+			    size_t len, loff_t *ppos)
+{
+	struct moxtet *moxtet = file->private_data;
+	u8 bin[TURRIS_MOX_MAX_MODULES];
+	u8 hex[sizeof(bin) * 2 + 1];
+	size_t res;
+	loff_t dummy = 0;
+	int err, i;
+
+	if (len > 2 * moxtet->count + 1 || len < 2 * moxtet->count)
+		return -EINVAL;
+
+	res = simple_write_to_buffer(hex, sizeof(hex), &dummy, buf, len);
+	if (res < 0)
+		return res;
+
+	if (len % 2 == 1 && hex[len - 1] != '\n')
+		return -EINVAL;
+
+	err = hex2bin(bin, hex, moxtet->count);
+	if (err < 0)
+		return -EINVAL;
+
+	mutex_lock(&moxtet->lock);
+
+	for (i = 0; i < moxtet->count; ++i)
+		moxtet->tx[moxtet->count - i] = bin[i];
+
+	err = spi_write(to_spi_device(moxtet->dev), moxtet->tx,
+			moxtet->count + 1);
+
+	mutex_unlock(&moxtet->lock);
+
+	return err < 0 ? err : len;
+}
+
+static const struct file_operations output_fops = {
+	.owner	= THIS_MODULE,
+	.open	= moxtet_debug_open,
+	.read	= output_read,
+	.write	= output_write,
+	.llseek	= no_llseek,
+};
+
+static int moxtet_register_debugfs(struct moxtet *moxtet)
+{
+	struct dentry *root, *entry;
+
+	root = debugfs_create_dir("moxtet", NULL);
+
+	if (IS_ERR(root))
+		return PTR_ERR(root);
+
+	entry = debugfs_create_file_unsafe("input", 0444, root, moxtet,
+					   &input_fops);
+	if (IS_ERR(entry))
+		goto err_remove;
+
+	entry = debugfs_create_file_unsafe("output", 0644, root, moxtet,
+					   &output_fops);
+	if (IS_ERR(entry))
+		goto err_remove;
+
+	moxtet->debugfs_root = root;
+
+	return 0;
+err_remove:
+	debugfs_remove_recursive(root);
+	return PTR_ERR(entry);
+}
+
+static void moxtet_unregister_debugfs(struct moxtet *moxtet)
+{
+	debugfs_remove_recursive(moxtet->debugfs_root);
+}
+#else
+static inline int moxtet_register_debugfs(struct moxtet *moxtet)
+{
+	return 0;
+}
+
+static inline void moxtet_unregister_debugfs(struct moxtet *moxtet)
+{
+}
+#endif
+
+static int moxtet_irq_domain_map(struct irq_domain *d, unsigned int irq,
+				 irq_hw_number_t hw)
+{
+	struct moxtet *moxtet = d->host_data;
+
+	if (hw >= MOXTET_NIRQS || !(moxtet->irq.exists & BIT(hw))) {
+		dev_err(moxtet->dev, "Invalid hw irq number\n");
+		return -EINVAL;
+	}
+
+	irq_set_chip_data(irq, d->host_data);
+	irq_set_chip_and_handler(irq, &moxtet->irq.chip, handle_level_irq);
+
+	return 0;
+}
+
+static int moxtet_irq_domain_xlate(struct irq_domain *d,
+				   struct device_node *ctrlr,
+				   const u32 *intspec, unsigned int intsize,
+				   unsigned long *out_hwirq,
+				   unsigned int *out_type)
+{
+	struct moxtet *moxtet = d->host_data;
+	int irq;
+
+	if (WARN_ON(intsize < 1))
+		return -EINVAL;
+
+	irq = intspec[0];
+
+	if (irq >= MOXTET_NIRQS || !(moxtet->irq.exists & BIT(irq)))
+		return -EINVAL;
+
+	*out_hwirq = irq;
+	*out_type = IRQ_TYPE_NONE;
+	return 0;
+}
+
+static const struct irq_domain_ops moxtet_irq_domain = {
+	.map = moxtet_irq_domain_map,
+	.xlate = moxtet_irq_domain_xlate,
+};
+
+static void moxtet_irq_mask(struct irq_data *d)
+{
+	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
+
+	moxtet->irq.masked |= BIT(d->hwirq);
+}
+
+static void moxtet_irq_unmask(struct irq_data *d)
+{
+	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
+
+	moxtet->irq.masked &= ~BIT(d->hwirq);
+}
+
+static void moxtet_irq_print_chip(struct irq_data *d, struct seq_file *p)
+{
+	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
+	struct moxtet_irqpos *pos = &moxtet->irq.position[d->hwirq];
+	int id;
+
+	id = moxtet->modules[pos->idx];
+
+	seq_printf(p, " moxtet-%s.%i#%i", mox_module_name(id), pos->idx,
+		   pos->bit);
+}
+
+static const struct irq_chip moxtet_irq_chip = {
+	.name			= "moxtet",
+	.irq_mask		= moxtet_irq_mask,
+	.irq_unmask		= moxtet_irq_unmask,
+	.irq_print_chip		= moxtet_irq_print_chip,
+};
+
+static int moxtet_irq_read(struct moxtet *moxtet, unsigned long *map)
+{
+	struct moxtet_irqpos *pos = moxtet->irq.position;
+	u8 buf[TURRIS_MOX_MAX_MODULES];
+	int i, ret;
+
+	ret = moxtet_spi_read(moxtet, buf);
+	if (ret < 0)
+		return ret;
+
+	*map = 0;
+
+	for_each_set_bit(i, &moxtet->irq.exists, MOXTET_NIRQS) {
+		if (!(buf[pos[i].idx + 1] & BIT(4 + pos[i].bit)))
+			set_bit(i, map);
+	}
+
+	return 0;
+}
+
+static irqreturn_t moxtet_irq_thread_fn(int irq, void *data)
+{
+	struct moxtet *moxtet = data;
+	unsigned long set;
+	int nhandled = 0, i, sub_irq, ret;
+
+	ret = moxtet_irq_read(moxtet, &set);
+	if (ret < 0)
+		goto out;
+
+	set &= ~moxtet->irq.masked;
+
+	do {
+		for_each_set_bit(i, &set, MOXTET_NIRQS) {
+			sub_irq = irq_find_mapping(moxtet->irq.domain, i);
+			handle_nested_irq(sub_irq);
+			dev_dbg(moxtet->dev, "%i irq\n", i);
+			++nhandled;
+		}
+
+		ret = moxtet_irq_read(moxtet, &set);
+		if (ret < 0)
+			goto out;
+
+		set &= ~moxtet->irq.masked;
+	} while (set);
+
+out:
+	return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
+}
+
+static void moxtet_irq_free(struct moxtet *moxtet)
+{
+	int i, irq;
+
+	for (i = 0; i < MOXTET_NIRQS; ++i) {
+		if (moxtet->irq.exists & BIT(i)) {
+			irq = irq_find_mapping(moxtet->irq.domain, i);
+			irq_dispose_mapping(irq);
+		}
+	}
+
+	irq_domain_remove(moxtet->irq.domain);
+}
+
+static int moxtet_irq_setup(struct moxtet *moxtet)
+{
+	int i, ret;
+
+	moxtet->irq.domain = irq_domain_add_simple(moxtet->dev->of_node,
+						   MOXTET_NIRQS, 0,
+						   &moxtet_irq_domain, moxtet);
+	if (moxtet->irq.domain == NULL) {
+		dev_err(moxtet->dev, "Could not add IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < MOXTET_NIRQS; ++i)
+		if (moxtet->irq.exists & BIT(i))
+			irq_create_mapping(moxtet->irq.domain, i);
+
+	moxtet->irq.chip = moxtet_irq_chip;
+	moxtet->irq.masked = ~0;
+
+	ret = request_threaded_irq(moxtet->dev_irq, NULL, moxtet_irq_thread_fn,
+				   IRQF_ONESHOT, "moxtet", moxtet);
+	if (ret < 0)
+		goto err_free;
+
+	return 0;
+
+err_free:
+	moxtet_irq_free(moxtet);
+	return ret;
+}
+
+static int moxtet_probe(struct spi_device *spi)
+{
+	struct moxtet *moxtet;
+	int ret;
+
+	ret = spi_setup(spi);
+	if (ret < 0)
+		return ret;
+
+	moxtet = devm_kzalloc(&spi->dev, sizeof(struct moxtet),
+			      GFP_KERNEL);
+	if (!moxtet)
+		return -ENOMEM;
+
+	moxtet->dev = &spi->dev;
+	spi_set_drvdata(spi, moxtet);
+
+	mutex_init(&moxtet->lock);
+
+	moxtet->dev_irq = of_irq_get(moxtet->dev->of_node, 0);
+	if (moxtet->dev_irq == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	if (moxtet->dev_irq <= 0) {
+		dev_err(moxtet->dev, "No IRQ resource found\n");
+		return -ENXIO;
+	}
+
+	ret = moxtet_find_topology(moxtet);
+	if (ret < 0)
+		return ret;
+
+	if (moxtet->irq.exists) {
+		ret = moxtet_irq_setup(moxtet);
+		if (ret < 0)
+			return ret;
+	}
+
+	of_register_moxtet_devices(moxtet);
+	moxtet_register_devices_from_topology(moxtet);
+
+	ret = moxtet_register_debugfs(moxtet);
+	if (ret < 0)
+		dev_warn(moxtet->dev, "Failed creating debugfs entries: %i\n",
+			 ret);
+
+	return 0;
+}
+
+static int moxtet_remove(struct spi_device *spi)
+{
+	struct moxtet *moxtet = spi_get_drvdata(spi);
+	int dummy;
+
+	free_irq(moxtet->dev_irq, moxtet);
+
+	moxtet_irq_free(moxtet);
+
+	moxtet_unregister_debugfs(moxtet);
+
+	dummy = device_for_each_child(moxtet->dev, NULL, __unregister);
+
+	mutex_destroy(&moxtet->lock);
+
+	return 0;
+}
+
+static const struct of_device_id moxtet_dt_ids[] = {
+	{ .compatible = "cznic,moxtet" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, moxtet_dt_ids);
+
+static struct spi_driver moxtet_spi_driver = {
+	.driver = {
+		.name		= "moxtet",
+		.of_match_table = moxtet_dt_ids,
+	},
+	.probe		= moxtet_probe,
+	.remove		= moxtet_remove,
+};
+
+static int __init moxtet_init(void)
+{
+	int ret;
+
+	ret = bus_register(&moxtet_bus_type);
+	if (ret < 0) {
+		pr_err("moxtet bus registration failed: %d\n", ret);
+		goto error;
+	}
+
+	ret = spi_register_driver(&moxtet_spi_driver);
+	if (ret < 0) {
+		pr_err("moxtet spi driver registration failed: %d\n", ret);
+		goto error_bus;
+	}
+
+	return 0;
+
+error_bus:
+	bus_unregister(&moxtet_bus_type);
+error:
+	return ret;
+}
+postcore_initcall_sync(moxtet_init);
+
+static void __exit moxtet_exit(void)
+{
+	spi_unregister_driver(&moxtet_spi_driver);
+	bus_unregister(&moxtet_bus_type);
+}
+module_exit(moxtet_exit);
+
+MODULE_AUTHOR("Marek Behun <marek.behun@nic.cz>");
+MODULE_DESCRIPTION("CZ.NIC's Turris Mox module configuration bus");
+MODULE_LICENSE("GPL v2");
diff --git a/include/dt-bindings/bus/moxtet.h b/include/dt-bindings/bus/moxtet.h
new file mode 100644
index 000000000000..dc9345440ebe
--- /dev/null
+++ b/include/dt-bindings/bus/moxtet.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Constant for device tree bindings for Turris Mox module configuration bus
+ *
+ * Copyright (C) 2019 Marek Behun <marek.behun@nic.cz>
+ */
+
+#ifndef _DT_BINDINGS_BUS_MOXTET_H
+#define _DT_BINDINGS_BUS_MOXTET_H
+
+#define MOXTET_IRQ_PCI		0
+#define MOXTET_IRQ_USB3		4
+#define MOXTET_IRQ_PERIDOT(n)	(8 + (n))
+#define MOXTET_IRQ_TOPAZ	12
+
+#endif /* _DT_BINDINGS_BUS_MOXTET_H */
diff --git a/include/linux/moxtet.h b/include/linux/moxtet.h
new file mode 100644
index 000000000000..490db6886dcc
--- /dev/null
+++ b/include/linux/moxtet.h
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Turris Mox module configuration bus driver
+ *
+ * Copyright (C) 2019 Marek Behun <marek.behun@nic.cz>
+ */
+
+#ifndef __LINUX_MOXTET_H
+#define __LINUX_MOXTET_H
+
+#include <linux/device.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mutex.h>
+
+#define TURRIS_MOX_MAX_MODULES	10
+
+enum turris_mox_cpu_module_id {
+	TURRIS_MOX_CPU_ID_EMMC	= 0x00,
+	TURRIS_MOX_CPU_ID_SD	= 0x10,
+};
+
+enum turris_mox_module_id {
+	TURRIS_MOX_MODULE_FIRST		= 0x01,
+
+	TURRIS_MOX_MODULE_SFP		= 0x01,
+	TURRIS_MOX_MODULE_PCI		= 0x02,
+	TURRIS_MOX_MODULE_TOPAZ		= 0x03,
+	TURRIS_MOX_MODULE_PERIDOT	= 0x04,
+	TURRIS_MOX_MODULE_USB3		= 0x05,
+	TURRIS_MOX_MODULE_PCI_BRIDGE	= 0x06,
+
+	TURRIS_MOX_MODULE_LAST		= 0x06,
+};
+
+#define MOXTET_NIRQS	16
+
+extern struct bus_type moxtet_type;
+
+struct moxtet {
+	struct device			*dev;
+	struct mutex			lock;
+	u8				modules[TURRIS_MOX_MAX_MODULES];
+	int				count;
+	u8				tx[TURRIS_MOX_MAX_MODULES];
+	int				dev_irq;
+	struct {
+		struct irq_domain	*domain;
+		struct irq_chip		chip;
+		unsigned long		masked, exists;
+		struct moxtet_irqpos {
+					u8 idx;
+					u8 bit;
+		} position[MOXTET_NIRQS];
+	} irq;
+#ifdef CONFIG_DEBUG_FS
+	struct dentry			*debugfs_root;
+#endif
+};
+
+struct moxtet_driver {
+	const enum turris_mox_module_id	*id_table;
+	struct device_driver		driver;
+};
+
+static inline struct moxtet_driver *
+to_moxtet_driver(struct device_driver *drv)
+{
+	if (!drv)
+		return NULL;
+	return container_of(drv, struct moxtet_driver, driver);
+}
+
+extern int __moxtet_register_driver(struct module *owner,
+				    struct moxtet_driver *mdrv);
+
+static inline void moxtet_unregister_driver(struct moxtet_driver *mdrv)
+{
+	if (mdrv)
+		driver_unregister(&mdrv->driver);
+}
+
+#define moxtet_register_driver(driver) \
+	__moxtet_register_driver(THIS_MODULE, driver)
+
+#define module_moxtet_driver(__moxtet_driver) \
+	module_driver(__moxtet_driver, moxtet_register_driver, \
+			moxtet_unregister_driver)
+
+struct moxtet_device {
+	struct device			dev;
+	struct moxtet			*moxtet;
+	enum turris_mox_module_id	id;
+	unsigned int			idx;
+};
+
+extern int moxtet_device_read(struct device *dev);
+extern int moxtet_device_write(struct device *dev, u8 val);
+extern int moxtet_device_written(struct device *dev);
+
+static inline struct moxtet_device *
+to_moxtet_device(struct device *dev)
+{
+	if (!dev)
+		return NULL;
+	return container_of(dev, struct moxtet_device, dev);
+}
+
+#endif /* __LINUX_MOXTET_H */
-- 
2.19.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v4 armsoc/drivers/bus+gpio 1/5] bus: Add support for Moxtet bus

[Marek Behún]

On the Turris Mox router different modules can be connected to the main
CPU board: currently a module with a SFP cage, a module with MiniPCIe
connector, a PCIe pass-through MiniPCIe connector module, a 4-port
switch module, an 8-port switch module, and a 4-port USB3 module.

For example:
  [CPU]-[PCIe-pass-through]-[PCIe]-[8-port switch]-[8-port switch]-[SFP]

Each of this modules has an input and output shift register, and these
are connected via SPI to the CPU board.

Via SPI we are able to discover which modules are connected, in which
order, and we can also read some information about the modules (eg.
their interrupt status), and configure them.
From each module 8 bits can be read (of which low 4 bits identify the
module) and 8 bits can be written.

For example from the module with a SFP cage we can read the LOS,
TX-FAULT and MOD-DEF0 signals, while we can write TX-DISABLE and
RATE-SELECT signals.

This driver creates a new bus type, called "moxtet". For each Mox module
it finds via SPI, it creates a new device on the moxtet bus so that
drivers can be written for them.

It also implements a virtual interrupt controller for the modules which
send their interrupt status over the SPI shift register. These modules
do this in addition to sending their interrupt status via the shared
interrupt line. When the shared interrupt is triggered, we read from the
shift register and handle IRQs for all devices which are in interrupt.

The topology of how Mox modules are connected can then be read by
listing /sys/bus/moxtet/devices.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
 MAINTAINERS                      |   7 +
 drivers/bus/Kconfig              |  10 +
 drivers/bus/Makefile             |   1 +
 drivers/bus/moxtet.c             | 886 +++++++++++++++++++++++++++++++
 include/dt-bindings/bus/moxtet.h |  16 +
 include/linux/moxtet.h           | 109 ++++
 6 files changed, 1029 insertions(+)
 create mode 100644 drivers/bus/moxtet.c
 create mode 100644 include/dt-bindings/bus/moxtet.h
 create mode 100644 include/linux/moxtet.h

diff --git a/MAINTAINERS b/MAINTAINERS
index a419acaa01c5..d96d36c83bc3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1498,6 +1498,13 @@ F:	drivers/clocksource/timer-atlas7.c
 N:	[^a-z]sirf
 X:	drivers/gnss
 
+ARM/CZ.NIC TURRIS MOX SUPPORT
+M:	Marek Behun <marek.behun@nic.cz>
+W:	http://mox.turris.cz
+S:	Maintained
+F:	include/linux/moxtet.h
+F:	drivers/bus/moxtet.c
+
 ARM/EBSA110 MACHINE SUPPORT
 M:	Russell King <linux@armlinux.org.uk>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 1851112ccc29..6b331061d34b 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -29,6 +29,16 @@ config BRCMSTB_GISB_ARB
 	  arbiter. This driver provides timeout and target abort error handling
 	  and internal bus master decoding.
 
+config MOXTET
+	tristate "CZ.NIC Turris Mox module configuration bus"
+	depends on SPI_MASTER && OF
+	help
+	  Say yes here to add support for the module configuration bus found
+	  on CZ.NIC's Turris Mox. This is needed for the ability to discover
+	  the order in which the modules are connected and to get/set some of
+	  their settings. For example the GPIOs on Mox SFP module are
+	  configured through this bus.
+
 config HISILICON_LPC
 	bool "Support for ISA I/O space on HiSilicon Hip06/7"
 	depends on ARM64 && (ARCH_HISI || COMPILE_TEST)
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index ca300b1914ce..16b43d3468c6 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_ARM_CCI)		+= arm-cci.o
 
 obj-$(CONFIG_HISILICON_LPC)	+= hisi_lpc.o
 obj-$(CONFIG_BRCMSTB_GISB_ARB)	+= brcmstb_gisb.o
+obj-$(CONFIG_MOXTET)		+= moxtet.o
 
 # DPAA2 fsl-mc bus
 obj-$(CONFIG_FSL_MC_BUS)	+= fsl-mc/
diff --git a/drivers/bus/moxtet.c b/drivers/bus/moxtet.c
new file mode 100644
index 000000000000..1ee4570e7e17
--- /dev/null
+++ b/drivers/bus/moxtet.c
@@ -0,0 +1,886 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Turris Mox module configuration bus driver
+ *
+ * Copyright (C) 2019 Marek Behun <marek.behun@nic.cz>
+ */
+
+#include <dt-bindings/bus/moxtet.h>
+#include <linux/bitops.h>
+#include <linux/debugfs.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/moxtet.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/spi/spi.h>
+
+/*
+ * @name:	module name for sysfs
+ * @hwirq_base:	base index for IRQ for this module (-1 if no IRQs)
+ * @nirqs:	how many interrupts does the shift register provide
+ * @desc:	module description for kernel log
+ */
+static const struct {
+	const char *name;
+	int hwirq_base;
+	int nirqs;
+	const char *desc;
+} mox_module_table[] = {
+	/* do not change order of this array! */
+	{ NULL,		 0,			0, NULL },
+	{ "sfp",	-1,			0, "MOX D (SFP cage)" },
+	{ "pci",	MOXTET_IRQ_PCI,		1, "MOX B (Mini-PCIe)" },
+	{ "topaz",	MOXTET_IRQ_TOPAZ,	1, "MOX C (4 port switch)" },
+	{ "peridot",	MOXTET_IRQ_PERIDOT(0),	1, "MOX E (8 port switch)" },
+	{ "usb3",	MOXTET_IRQ_USB3,	2, "MOX F (USB 3.0)" },
+	{ "pci-bridge",	-1,			0, "MOX G (Mini-PCIe bridge)" },
+};
+
+static inline bool mox_module_known(unsigned int id)
+{
+	return id >= TURRIS_MOX_MODULE_FIRST && id <= TURRIS_MOX_MODULE_LAST;
+}
+
+static inline const char *mox_module_name(unsigned int id)
+{
+	if (mox_module_known(id))
+		return mox_module_table[id].name;
+	else
+		return "unknown";
+}
+
+#define DEF_MODULE_ATTR(name, fmt, ...)					\
+static ssize_t								\
+module_##name##_show(struct device *dev, struct device_attribute *a,	\
+		     char *buf)						\
+{									\
+	struct moxtet_device *mdev = to_moxtet_device(dev);		\
+	return sprintf(buf, (fmt), __VA_ARGS__);			\
+}									\
+static DEVICE_ATTR_RO(module_##name)
+
+DEF_MODULE_ATTR(id, "0x%x\n", mdev->id);
+DEF_MODULE_ATTR(name, "%s\n", mox_module_name(mdev->id));
+DEF_MODULE_ATTR(description, "%s\n",
+		mox_module_known(mdev->id) ? mox_module_table[mdev->id].desc
+					   : "");
+
+static struct attribute *moxtet_dev_attrs[] = {
+	&dev_attr_module_id.attr,
+	&dev_attr_module_name.attr,
+	&dev_attr_module_description.attr,
+	NULL,
+};
+
+static const struct attribute_group moxtet_dev_group = {
+	.attrs = moxtet_dev_attrs,
+};
+
+static const struct attribute_group *moxtet_dev_groups[] = {
+	&moxtet_dev_group,
+	NULL,
+};
+
+static int moxtet_match(struct device *dev, struct device_driver *drv)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet_driver *tdrv = to_moxtet_driver(drv);
+	const enum turris_mox_module_id *t;
+
+	if (of_driver_match_device(dev, drv))
+		return 1;
+
+	if (!tdrv->id_table)
+		return 0;
+
+	for (t = tdrv->id_table; *t; ++t)
+		if (*t == mdev->id)
+			return 1;
+
+	return 0;
+}
+
+struct bus_type moxtet_bus_type = {
+	.name		= "moxtet",
+	.dev_groups	= moxtet_dev_groups,
+	.match		= moxtet_match,
+};
+EXPORT_SYMBOL_GPL(moxtet_bus_type);
+
+int __moxtet_register_driver(struct module *owner,
+			     struct moxtet_driver *mdrv)
+{
+	mdrv->driver.owner = owner;
+	mdrv->driver.bus = &moxtet_bus_type;
+	return driver_register(&mdrv->driver);
+}
+EXPORT_SYMBOL_GPL(__moxtet_register_driver);
+
+static int moxtet_dev_check(struct device *dev, void *data)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet_device *new_dev = data;
+
+	if (mdev->moxtet == new_dev->moxtet && mdev->id == new_dev->id &&
+	    mdev->idx == new_dev->idx)
+		return -EBUSY;
+	return 0;
+}
+
+static void moxtet_dev_release(struct device *dev)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+
+	put_device(mdev->moxtet->dev);
+	kfree(mdev);
+}
+
+static struct moxtet_device *
+moxtet_alloc_device(struct moxtet *moxtet)
+{
+	struct moxtet_device *dev;
+
+	if (!get_device(moxtet->dev))
+		return NULL;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev) {
+		put_device(moxtet->dev);
+		return NULL;
+	}
+
+	dev->moxtet = moxtet;
+	dev->dev.parent = moxtet->dev;
+	dev->dev.bus = &moxtet_bus_type;
+	dev->dev.release = moxtet_dev_release;
+
+	device_initialize(&dev->dev);
+
+	return dev;
+}
+
+static int moxtet_add_device(struct moxtet_device *dev)
+{
+	static DEFINE_MUTEX(add_mutex);
+	int ret;
+
+	if (dev->idx >= TURRIS_MOX_MAX_MODULES || dev->id > 0xf)
+		return -EINVAL;
+
+	dev_set_name(&dev->dev, "moxtet-%s.%u", mox_module_name(dev->id),
+		     dev->idx);
+
+	mutex_lock(&add_mutex);
+
+	ret = bus_for_each_dev(&moxtet_bus_type, NULL, dev,
+			       moxtet_dev_check);
+	if (ret)
+		goto done;
+
+	ret = device_add(&dev->dev);
+	if (ret < 0)
+		dev_err(dev->moxtet->dev, "can't add %s, status %d\n",
+			dev_name(dev->moxtet->dev), ret);
+
+done:
+	mutex_unlock(&add_mutex);
+	return ret;
+}
+
+static int __unregister(struct device *dev, void *null)
+{
+	if (dev->of_node) {
+		of_node_clear_flag(dev->of_node, OF_POPULATED);
+		of_node_put(dev->of_node);
+	}
+
+	device_unregister(dev);
+
+	return 0;
+}
+
+static struct moxtet_device *
+of_register_moxtet_device(struct moxtet *moxtet, struct device_node *nc)
+{
+	struct moxtet_device *dev;
+	u32 val;
+	int ret;
+
+	dev = moxtet_alloc_device(moxtet);
+	if (!dev) {
+		dev_err(moxtet->dev,
+			"Moxtet device alloc error for %pOF\n", nc);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ret = of_property_read_u32(nc, "reg", &val);
+	if (ret) {
+		dev_err(moxtet->dev, "%pOF has no valid 'reg' property (%d)\n",
+			nc, ret);
+		goto err_put;
+	}
+
+	dev->idx = val;
+
+	if (dev->idx >= TURRIS_MOX_MAX_MODULES) {
+		dev_err(moxtet->dev, "%pOF Moxtet address 0x%x out of range\n",
+			nc, dev->idx);
+		ret = -EINVAL;
+		goto err_put;
+	}
+
+	dev->id = moxtet->modules[dev->idx];
+
+	if (!dev->id) {
+		dev_err(moxtet->dev, "%pOF Moxtet address 0x%x is empty\n", nc,
+			dev->idx);
+		ret = -ENODEV;
+		goto err_put;
+	}
+
+	of_node_get(nc);
+	dev->dev.of_node = nc;
+
+	ret = moxtet_add_device(dev);
+	if (ret) {
+		dev_err(moxtet->dev,
+			"Moxtet device register error for %pOF\n", nc);
+		of_node_put(nc);
+		goto err_put;
+	}
+
+	return dev;
+
+err_put:
+	put_device(&dev->dev);
+	return ERR_PTR(ret);
+}
+
+static void of_register_moxtet_devices(struct moxtet *moxtet)
+{
+	struct moxtet_device *dev;
+	struct device_node *nc;
+
+	if (!moxtet->dev->of_node)
+		return;
+
+	for_each_available_child_of_node(moxtet->dev->of_node, nc) {
+		if (of_node_test_and_set_flag(nc, OF_POPULATED))
+			continue;
+		dev = of_register_moxtet_device(moxtet, nc);
+		if (IS_ERR(dev)) {
+			dev_warn(moxtet->dev,
+				 "Failed to create Moxtet device for %pOF\n",
+				 nc);
+			of_node_clear_flag(nc, OF_POPULATED);
+		}
+	}
+}
+
+static void
+moxtet_register_devices_from_topology(struct moxtet *moxtet)
+{
+	struct moxtet_device *dev;
+	int i, ret;
+
+	for (i = 0; i < moxtet->count; ++i) {
+		dev = moxtet_alloc_device(moxtet);
+		if (!dev) {
+			dev_err(moxtet->dev, "Moxtet device %u alloc error\n",
+				i);
+			continue;
+		}
+
+		dev->idx = i;
+		dev->id = moxtet->modules[i];
+
+		ret = moxtet_add_device(dev);
+		if (ret && ret != -EBUSY) {
+			put_device(&dev->dev);
+			dev_err(moxtet->dev,
+				"Moxtet device %u register error: %i\n", i,
+				ret);
+		}
+	}
+}
+
+/*
+ * @nsame:	how many modules with same id are already in moxtet->modules
+ */
+static int moxtet_set_irq(struct moxtet *moxtet, int idx, int id, int nsame)
+{
+	int i, first;
+	struct moxtet_irqpos *pos;
+
+	first = mox_module_table[id].hwirq_base +
+		nsame * mox_module_table[id].nirqs;
+
+	if (first + mox_module_table[id].nirqs > MOXTET_NIRQS)
+		return -EINVAL;
+
+	for (i = 0; i < mox_module_table[id].nirqs; ++i) {
+		pos = &moxtet->irq.position[first + i];
+		pos->idx = idx;
+		pos->bit = i;
+		moxtet->irq.exists |= BIT(first + i);
+	}
+
+	return 0;
+}
+
+static int moxtet_find_topology(struct moxtet *moxtet)
+{
+	u8 buf[TURRIS_MOX_MAX_MODULES];
+	int cnts[TURRIS_MOX_MODULE_LAST];
+	int i, ret;
+
+	memset(cnts, 0, sizeof(cnts));
+
+	ret = spi_read(to_spi_device(moxtet->dev), buf, TURRIS_MOX_MAX_MODULES);
+	if (ret < 0)
+		return ret;
+
+	if (buf[0] == TURRIS_MOX_CPU_ID_EMMC) {
+		dev_info(moxtet->dev, "Found MOX A (eMMC CPU) module\n");
+	} else if (buf[0] == TURRIS_MOX_CPU_ID_SD) {
+		dev_info(moxtet->dev, "Found MOX A (CPU) module\n");
+	} else {
+		dev_err(moxtet->dev, "Invalid Turris MOX A CPU module 0x%02x\n",
+			buf[0]);
+		return -ENODEV;
+	}
+
+	moxtet->count = 0;
+
+	for (i = 1; i < TURRIS_MOX_MAX_MODULES; ++i) {
+		int id;
+
+		if (buf[i] == 0xff)
+			break;
+
+		id = buf[i] & 0xf;
+
+		moxtet->modules[i-1] = id;
+		++moxtet->count;
+
+		if (mox_module_known(id)) {
+			dev_info(moxtet->dev, "Found %s module\n",
+				 mox_module_table[id].desc);
+
+			if (moxtet_set_irq(moxtet, i-1, id, cnts[id]++) < 0)
+				dev_err(moxtet->dev,
+					"  Cannot set IRQ for module %s\n",
+					mox_module_table[id].desc);
+		} else {
+			dev_warn(moxtet->dev,
+				 "Unknown Moxtet module found (ID 0x%02x)\n",
+				 id);
+		}
+	}
+
+	return 0;
+}
+
+static int moxtet_spi_read(struct moxtet *moxtet, u8 *buf)
+{
+	struct spi_transfer xfer = {
+		.rx_buf = buf,
+		.tx_buf = moxtet->tx,
+		.len = moxtet->count + 1
+	};
+	int ret;
+
+	mutex_lock(&moxtet->lock);
+
+	ret = spi_sync_transfer(to_spi_device(moxtet->dev), &xfer, 1);
+
+	mutex_unlock(&moxtet->lock);
+
+	return ret;
+}
+
+int moxtet_device_read(struct device *dev)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet *moxtet = mdev->moxtet;
+	u8 buf[TURRIS_MOX_MAX_MODULES];
+	int ret;
+
+	if (mdev->idx >= moxtet->count)
+		return -EINVAL;
+
+	ret = moxtet_spi_read(moxtet, buf);
+	if (ret < 0)
+		return ret;
+
+	return buf[mdev->idx + 1] >> 4;
+}
+EXPORT_SYMBOL_GPL(moxtet_device_read);
+
+int moxtet_device_write(struct device *dev, u8 val)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet *moxtet = mdev->moxtet;
+	int ret;
+
+	if (mdev->idx >= moxtet->count)
+		return -EINVAL;
+
+	mutex_lock(&moxtet->lock);
+
+	moxtet->tx[moxtet->count - mdev->idx] = val;
+
+	ret = spi_write(to_spi_device(moxtet->dev), moxtet->tx,
+			moxtet->count + 1);
+
+	mutex_unlock(&moxtet->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(moxtet_device_write);
+
+int moxtet_device_written(struct device *dev)
+{
+	struct moxtet_device *mdev = to_moxtet_device(dev);
+	struct moxtet *moxtet = mdev->moxtet;
+
+	if (mdev->idx >= moxtet->count)
+		return -EINVAL;
+
+	return moxtet->tx[moxtet->count - mdev->idx];
+}
+EXPORT_SYMBOL_GPL(moxtet_device_written);
+
+#ifdef CONFIG_DEBUG_FS
+static int moxtet_debug_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+
+	return nonseekable_open(inode, file);
+}
+
+static ssize_t input_read(struct file *file, char __user *buf, size_t len,
+			  loff_t *ppos)
+{
+	struct moxtet *moxtet = file->private_data;
+	u8 bin[TURRIS_MOX_MAX_MODULES];
+	u8 hex[sizeof(buf) * 2 + 1];
+	int ret, n;
+
+	ret = moxtet_spi_read(moxtet, bin);
+	if (ret < 0)
+		return ret;
+
+	n = moxtet->count + 1;
+	bin2hex(hex, bin, n);
+
+	hex[2*n] = '\n';
+
+	return simple_read_from_buffer(buf, len, ppos, hex, 2*n + 1);
+}
+
+static const struct file_operations input_fops = {
+	.owner	= THIS_MODULE,
+	.open	= moxtet_debug_open,
+	.read	= input_read,
+	.llseek	= no_llseek,
+};
+
+static ssize_t output_read(struct file *file, char __user *buf, size_t len,
+			   loff_t *ppos)
+{
+	struct moxtet *moxtet = file->private_data;
+	u8 hex[TURRIS_MOX_MAX_MODULES * 2 + 1];
+	u8 *p = hex;
+	int i;
+
+	mutex_lock(&moxtet->lock);
+
+	for (i = 0; i < moxtet->count; ++i)
+		p = hex_byte_pack(p, moxtet->tx[moxtet->count - i]);
+
+	mutex_unlock(&moxtet->lock);
+
+	*p++ = '\n';
+
+	return simple_read_from_buffer(buf, len, ppos, hex, p - hex);
+}
+
+static ssize_t output_write(struct file *file, const char __user *buf,
+			    size_t len, loff_t *ppos)
+{
+	struct moxtet *moxtet = file->private_data;
+	u8 bin[TURRIS_MOX_MAX_MODULES];
+	u8 hex[sizeof(bin) * 2 + 1];
+	size_t res;
+	loff_t dummy = 0;
+	int err, i;
+
+	if (len > 2 * moxtet->count + 1 || len < 2 * moxtet->count)
+		return -EINVAL;
+
+	res = simple_write_to_buffer(hex, sizeof(hex), &dummy, buf, len);
+	if (res < 0)
+		return res;
+
+	if (len % 2 == 1 && hex[len - 1] != '\n')
+		return -EINVAL;
+
+	err = hex2bin(bin, hex, moxtet->count);
+	if (err < 0)
+		return -EINVAL;
+
+	mutex_lock(&moxtet->lock);
+
+	for (i = 0; i < moxtet->count; ++i)
+		moxtet->tx[moxtet->count - i] = bin[i];
+
+	err = spi_write(to_spi_device(moxtet->dev), moxtet->tx,
+			moxtet->count + 1);
+
+	mutex_unlock(&moxtet->lock);
+
+	return err < 0 ? err : len;
+}
+
+static const struct file_operations output_fops = {
+	.owner	= THIS_MODULE,
+	.open	= moxtet_debug_open,
+	.read	= output_read,
+	.write	= output_write,
+	.llseek	= no_llseek,
+};
+
+static int moxtet_register_debugfs(struct moxtet *moxtet)
+{
+	struct dentry *root, *entry;
+
+	root = debugfs_create_dir("moxtet", NULL);
+
+	if (IS_ERR(root))
+		return PTR_ERR(root);
+
+	entry = debugfs_create_file_unsafe("input", 0444, root, moxtet,
+					   &input_fops);
+	if (IS_ERR(entry))
+		goto err_remove;
+
+	entry = debugfs_create_file_unsafe("output", 0644, root, moxtet,
+					   &output_fops);
+	if (IS_ERR(entry))
+		goto err_remove;
+
+	moxtet->debugfs_root = root;
+
+	return 0;
+err_remove:
+	debugfs_remove_recursive(root);
+	return PTR_ERR(entry);
+}
+
+static void moxtet_unregister_debugfs(struct moxtet *moxtet)
+{
+	debugfs_remove_recursive(moxtet->debugfs_root);
+}
+#else
+static inline int moxtet_register_debugfs(struct moxtet *moxtet)
+{
+	return 0;
+}
+
+static inline void moxtet_unregister_debugfs(struct moxtet *moxtet)
+{
+}
+#endif
+
+static int moxtet_irq_domain_map(struct irq_domain *d, unsigned int irq,
+				 irq_hw_number_t hw)
+{
+	struct moxtet *moxtet = d->host_data;
+
+	if (hw >= MOXTET_NIRQS || !(moxtet->irq.exists & BIT(hw))) {
+		dev_err(moxtet->dev, "Invalid hw irq number\n");
+		return -EINVAL;
+	}
+
+	irq_set_chip_data(irq, d->host_data);
+	irq_set_chip_and_handler(irq, &moxtet->irq.chip, handle_level_irq);
+
+	return 0;
+}
+
+static int moxtet_irq_domain_xlate(struct irq_domain *d,
+				   struct device_node *ctrlr,
+				   const u32 *intspec, unsigned int intsize,
+				   unsigned long *out_hwirq,
+				   unsigned int *out_type)
+{
+	struct moxtet *moxtet = d->host_data;
+	int irq;
+
+	if (WARN_ON(intsize < 1))
+		return -EINVAL;
+
+	irq = intspec[0];
+
+	if (irq >= MOXTET_NIRQS || !(moxtet->irq.exists & BIT(irq)))
+		return -EINVAL;
+
+	*out_hwirq = irq;
+	*out_type = IRQ_TYPE_NONE;
+	return 0;
+}
+
+static const struct irq_domain_ops moxtet_irq_domain = {
+	.map = moxtet_irq_domain_map,
+	.xlate = moxtet_irq_domain_xlate,
+};
+
+static void moxtet_irq_mask(struct irq_data *d)
+{
+	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
+
+	moxtet->irq.masked |= BIT(d->hwirq);
+}
+
+static void moxtet_irq_unmask(struct irq_data *d)
+{
+	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
+
+	moxtet->irq.masked &= ~BIT(d->hwirq);
+}
+
+static void moxtet_irq_print_chip(struct irq_data *d, struct seq_file *p)
+{
+	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
+	struct moxtet_irqpos *pos = &moxtet->irq.position[d->hwirq];
+	int id;
+
+	id = moxtet->modules[pos->idx];
+
+	seq_printf(p, " moxtet-%s.%i#%i", mox_module_name(id), pos->idx,
+		   pos->bit);
+}
+
+static const struct irq_chip moxtet_irq_chip = {
+	.name			= "moxtet",
+	.irq_mask		= moxtet_irq_mask,
+	.irq_unmask		= moxtet_irq_unmask,
+	.irq_print_chip		= moxtet_irq_print_chip,
+};
+
+static int moxtet_irq_read(struct moxtet *moxtet, unsigned long *map)
+{
+	struct moxtet_irqpos *pos = moxtet->irq.position;
+	u8 buf[TURRIS_MOX_MAX_MODULES];
+	int i, ret;
+
+	ret = moxtet_spi_read(moxtet, buf);
+	if (ret < 0)
+		return ret;
+
+	*map = 0;
+
+	for_each_set_bit(i, &moxtet->irq.exists, MOXTET_NIRQS) {
+		if (!(buf[pos[i].idx + 1] & BIT(4 + pos[i].bit)))
+			set_bit(i, map);
+	}
+
+	return 0;
+}
+
+static irqreturn_t moxtet_irq_thread_fn(int irq, void *data)
+{
+	struct moxtet *moxtet = data;
+	unsigned long set;
+	int nhandled = 0, i, sub_irq, ret;
+
+	ret = moxtet_irq_read(moxtet, &set);
+	if (ret < 0)
+		goto out;
+
+	set &= ~moxtet->irq.masked;
+
+	do {
+		for_each_set_bit(i, &set, MOXTET_NIRQS) {
+			sub_irq = irq_find_mapping(moxtet->irq.domain, i);
+			handle_nested_irq(sub_irq);
+			dev_dbg(moxtet->dev, "%i irq\n", i);
+			++nhandled;
+		}
+
+		ret = moxtet_irq_read(moxtet, &set);
+		if (ret < 0)
+			goto out;
+
+		set &= ~moxtet->irq.masked;
+	} while (set);
+
+out:
+	return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
+}
+
+static void moxtet_irq_free(struct moxtet *moxtet)
+{
+	int i, irq;
+
+	for (i = 0; i < MOXTET_NIRQS; ++i) {
+		if (moxtet->irq.exists & BIT(i)) {
+			irq = irq_find_mapping(moxtet->irq.domain, i);
+			irq_dispose_mapping(irq);
+		}
+	}
+
+	irq_domain_remove(moxtet->irq.domain);
+}
+
+static int moxtet_irq_setup(struct moxtet *moxtet)
+{
+	int i, ret;
+
+	moxtet->irq.domain = irq_domain_add_simple(moxtet->dev->of_node,
+						   MOXTET_NIRQS, 0,
+						   &moxtet_irq_domain, moxtet);
+	if (moxtet->irq.domain == NULL) {
+		dev_err(moxtet->dev, "Could not add IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < MOXTET_NIRQS; ++i)
+		if (moxtet->irq.exists & BIT(i))
+			irq_create_mapping(moxtet->irq.domain, i);
+
+	moxtet->irq.chip = moxtet_irq_chip;
+	moxtet->irq.masked = ~0;
+
+	ret = request_threaded_irq(moxtet->dev_irq, NULL, moxtet_irq_thread_fn,
+				   IRQF_ONESHOT, "moxtet", moxtet);
+	if (ret < 0)
+		goto err_free;
+
+	return 0;
+
+err_free:
+	moxtet_irq_free(moxtet);
+	return ret;
+}
+
+static int moxtet_probe(struct spi_device *spi)
+{
+	struct moxtet *moxtet;
+	int ret;
+
+	ret = spi_setup(spi);
+	if (ret < 0)
+		return ret;
+
+	moxtet = devm_kzalloc(&spi->dev, sizeof(struct moxtet),
+			      GFP_KERNEL);
+	if (!moxtet)
+		return -ENOMEM;
+
+	moxtet->dev = &spi->dev;
+	spi_set_drvdata(spi, moxtet);
+
+	mutex_init(&moxtet->lock);
+
+	moxtet->dev_irq = of_irq_get(moxtet->dev->of_node, 0);
+	if (moxtet->dev_irq == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	if (moxtet->dev_irq <= 0) {
+		dev_err(moxtet->dev, "No IRQ resource found\n");
+		return -ENXIO;
+	}
+
+	ret = moxtet_find_topology(moxtet);
+	if (ret < 0)
+		return ret;
+
+	if (moxtet->irq.exists) {
+		ret = moxtet_irq_setup(moxtet);
+		if (ret < 0)
+			return ret;
+	}
+
+	of_register_moxtet_devices(moxtet);
+	moxtet_register_devices_from_topology(moxtet);
+
+	ret = moxtet_register_debugfs(moxtet);
+	if (ret < 0)
+		dev_warn(moxtet->dev, "Failed creating debugfs entries: %i\n",
+			 ret);
+
+	return 0;
+}
+
+static int moxtet_remove(struct spi_device *spi)
+{
+	struct moxtet *moxtet = spi_get_drvdata(spi);
+	int dummy;
+
+	free_irq(moxtet->dev_irq, moxtet);
+
+	moxtet_irq_free(moxtet);
+
+	moxtet_unregister_debugfs(moxtet);
+
+	dummy = device_for_each_child(moxtet->dev, NULL, __unregister);
+
+	mutex_destroy(&moxtet->lock);
+
+	return 0;
+}
+
+static const struct of_device_id moxtet_dt_ids[] = {
+	{ .compatible = "cznic,moxtet" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, moxtet_dt_ids);
+
+static struct spi_driver moxtet_spi_driver = {
+	.driver = {
+		.name		= "moxtet",
+		.of_match_table = moxtet_dt_ids,
+	},
+	.probe		= moxtet_probe,
+	.remove		= moxtet_remove,
+};
+
+static int __init moxtet_init(void)
+{
+	int ret;
+
+	ret = bus_register(&moxtet_bus_type);
+	if (ret < 0) {
+		pr_err("moxtet bus registration failed: %d\n", ret);
+		goto error;
+	}
+
+	ret = spi_register_driver(&moxtet_spi_driver);
+	if (ret < 0) {
+		pr_err("moxtet spi driver registration failed: %d\n", ret);
+		goto error_bus;
+	}
+
+	return 0;
+
+error_bus:
+	bus_unregister(&moxtet_bus_type);
+error:
+	return ret;
+}
+postcore_initcall_sync(moxtet_init);
+
+static void __exit moxtet_exit(void)
+{
+	spi_unregister_driver(&moxtet_spi_driver);
+	bus_unregister(&moxtet_bus_type);
+}
+module_exit(moxtet_exit);
+
+MODULE_AUTHOR("Marek Behun <marek.behun@nic.cz>");
+MODULE_DESCRIPTION("CZ.NIC's Turris Mox module configuration bus");
+MODULE_LICENSE("GPL v2");
diff --git a/include/dt-bindings/bus/moxtet.h b/include/dt-bindings/bus/moxtet.h
new file mode 100644
index 000000000000..dc9345440ebe
--- /dev/null
+++ b/include/dt-bindings/bus/moxtet.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Constant for device tree bindings for Turris Mox module configuration bus
+ *
+ * Copyright (C) 2019 Marek Behun <marek.behun@nic.cz>
+ */
+
+#ifndef _DT_BINDINGS_BUS_MOXTET_H
+#define _DT_BINDINGS_BUS_MOXTET_H
+
+#define MOXTET_IRQ_PCI		0
+#define MOXTET_IRQ_USB3		4
+#define MOXTET_IRQ_PERIDOT(n)	(8 + (n))
+#define MOXTET_IRQ_TOPAZ	12
+
+#endif /* _DT_BINDINGS_BUS_MOXTET_H */
diff --git a/include/linux/moxtet.h b/include/linux/moxtet.h
new file mode 100644
index 000000000000..490db6886dcc
--- /dev/null
+++ b/include/linux/moxtet.h
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Turris Mox module configuration bus driver
+ *
+ * Copyright (C) 2019 Marek Behun <marek.behun@nic.cz>
+ */
+
+#ifndef __LINUX_MOXTET_H
+#define __LINUX_MOXTET_H
+
+#include <linux/device.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mutex.h>
+
+#define TURRIS_MOX_MAX_MODULES	10
+
+enum turris_mox_cpu_module_id {
+	TURRIS_MOX_CPU_ID_EMMC	= 0x00,
+	TURRIS_MOX_CPU_ID_SD	= 0x10,
+};
+
+enum turris_mox_module_id {
+	TURRIS_MOX_MODULE_FIRST		= 0x01,
+
+	TURRIS_MOX_MODULE_SFP		= 0x01,
+	TURRIS_MOX_MODULE_PCI		= 0x02,
+	TURRIS_MOX_MODULE_TOPAZ		= 0x03,
+	TURRIS_MOX_MODULE_PERIDOT	= 0x04,
+	TURRIS_MOX_MODULE_USB3		= 0x05,
+	TURRIS_MOX_MODULE_PCI_BRIDGE	= 0x06,
+
+	TURRIS_MOX_MODULE_LAST		= 0x06,
+};
+
+#define MOXTET_NIRQS	16
+
+extern struct bus_type moxtet_type;
+
+struct moxtet {
+	struct device			*dev;
+	struct mutex			lock;
+	u8				modules[TURRIS_MOX_MAX_MODULES];
+	int				count;
+	u8				tx[TURRIS_MOX_MAX_MODULES];
+	int				dev_irq;
+	struct {
+		struct irq_domain	*domain;
+		struct irq_chip		chip;
+		unsigned long		masked, exists;
+		struct moxtet_irqpos {
+					u8 idx;
+					u8 bit;
+		} position[MOXTET_NIRQS];
+	} irq;
+#ifdef CONFIG_DEBUG_FS
+	struct dentry			*debugfs_root;
+#endif
+};
+
+struct moxtet_driver {
+	const enum turris_mox_module_id	*id_table;
+	struct device_driver		driver;
+};
+
+static inline struct moxtet_driver *
+to_moxtet_driver(struct device_driver *drv)
+{
+	if (!drv)
+		return NULL;
+	return container_of(drv, struct moxtet_driver, driver);
+}
+
+extern int __moxtet_register_driver(struct module *owner,
+				    struct moxtet_driver *mdrv);
+
+static inline void moxtet_unregister_driver(struct moxtet_driver *mdrv)
+{
+	if (mdrv)
+		driver_unregister(&mdrv->driver);
+}
+
+#define moxtet_register_driver(driver) \
+	__moxtet_register_driver(THIS_MODULE, driver)
+
+#define module_moxtet_driver(__moxtet_driver) \
+	module_driver(__moxtet_driver, moxtet_register_driver, \
+			moxtet_unregister_driver)
+
+struct moxtet_device {
+	struct device			dev;
+	struct moxtet			*moxtet;
+	enum turris_mox_module_id	id;
+	unsigned int			idx;
+};
+
+extern int moxtet_device_read(struct device *dev);
+extern int moxtet_device_write(struct device *dev, u8 val);
+extern int moxtet_device_written(struct device *dev);
+
+static inline struct moxtet_device *
+to_moxtet_device(struct device *dev)
+{
+	if (!dev)
+		return NULL;
+	return container_of(dev, struct moxtet_device, dev);
+}
+
+#endif /* __LINUX_MOXTET_H */
-- 
2.19.2

Re: [PATCH v4 armsoc/drivers/bus+gpio 1/5] bus: Add support for Moxtet bus

[Linus Walleij]

On Thu, Mar 7, 2019 at 1:53 PM Marek Behún <marek.behun@nic.cz> wrote:

> On the Turris Mox router different modules can be connected to the main
> CPU board: currently a module with a SFP cage, a module with MiniPCIe
> connector, a PCIe pass-through MiniPCIe connector module, a 4-port
> switch module, an 8-port switch module, and a 4-port USB3 module.
>
> For example:
>   [CPU]-[PCIe-pass-through]-[PCIe]-[8-port switch]-[8-port switch]-[SFP]
>
> Each of this modules has an input and output shift register, and these
> are connected via SPI to the CPU board.
>
> Via SPI we are able to discover which modules are connected, in which
> order, and we can also read some information about the modules (eg.
> their interrupt status), and configure them.
> From each module 8 bits can be read (of which low 4 bits identify the
> module) and 8 bits can be written.
>
> For example from the module with a SFP cage we can read the LOS,
> TX-FAULT and MOD-DEF0 signals, while we can write TX-DISABLE and
> RATE-SELECT signals.
>
> This driver creates a new bus type, called "moxtet". For each Mox module
> it finds via SPI, it creates a new device on the moxtet bus so that
> drivers can be written for them.
>
> It also implements a virtual interrupt controller for the modules which
> send their interrupt status over the SPI shift register. These modules
> do this in addition to sending their interrupt status via the shared
> interrupt line. When the shared interrupt is triggered, we read from the
> shift register and handle IRQs for all devices which are in interrupt.
>
> The topology of how Mox modules are connected can then be read by
> listing /sys/bus/moxtet/devices.
>
> Signed-off-by: Marek Behún <marek.behun@nic.cz>

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

Yours,
Linus Walleij

Re: [PATCH v4 armsoc/drivers/bus+gpio 1/5] bus: Add support for Moxtet bus

[Linus Walleij]

On Thu, Mar 7, 2019 at 1:53 PM Marek Behún <marek.behun@nic.cz> wrote:

> On the Turris Mox router different modules can be connected to the main
> CPU board: currently a module with a SFP cage, a module with MiniPCIe
> connector, a PCIe pass-through MiniPCIe connector module, a 4-port
> switch module, an 8-port switch module, and a 4-port USB3 module.
>
> For example:
>   [CPU]-[PCIe-pass-through]-[PCIe]-[8-port switch]-[8-port switch]-[SFP]
>
> Each of this modules has an input and output shift register, and these
> are connected via SPI to the CPU board.
>
> Via SPI we are able to discover which modules are connected, in which
> order, and we can also read some information about the modules (eg.
> their interrupt status), and configure them.
> From each module 8 bits can be read (of which low 4 bits identify the
> module) and 8 bits can be written.
>
> For example from the module with a SFP cage we can read the LOS,
> TX-FAULT and MOD-DEF0 signals, while we can write TX-DISABLE and
> RATE-SELECT signals.
>
> This driver creates a new bus type, called "moxtet". For each Mox module
> it finds via SPI, it creates a new device on the moxtet bus so that
> drivers can be written for them.
>
> It also implements a virtual interrupt controller for the modules which
> send their interrupt status over the SPI shift register. These modules
> do this in addition to sending their interrupt status via the shared
> interrupt line. When the shared interrupt is triggered, we read from the
> shift register and handle IRQs for all devices which are in interrupt.
>
> The topology of how Mox modules are connected can then be read by
> listing /sys/bus/moxtet/devices.
>
> Signed-off-by: Marek Behún <marek.behun@nic.cz>

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

Yours,
Linus Walleij

_______________________________________________
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[PATCH v4 armsoc/drivers/bus+gpio 2/5] dt-bindings: bus: Document moxtet bus binding

[Marek Behún]

This adds device tree binding documentation for the Moxtet bus, a bus
via which the different modules connected to the Turris Mox router can
be configured.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 .../devicetree/bindings/bus/moxtet.txt        | 44 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 45 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt

diff --git a/Documentation/devicetree/bindings/bus/moxtet.txt b/Documentation/devicetree/bindings/bus/moxtet.txt
new file mode 100644
index 000000000000..7be9d00c1767
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/moxtet.txt
@@ -0,0 +1,44 @@
+Turris Mox module status and configuration bus (over SPI)
+
+Required properties:
+ - compatible		: Should be "cznic,moxtet"
+ - #address-cells	: Has to be 1
+ - #size-cells		: Has to be 0
+ - spi-cpol		: Required inverted clock polarity
+ - spi-cpha		: Required shifted clock phase
+ - interrupts		: Must contain reference to the shared interrupt line
+ - interrupt-controller	: Required
+ - #interrupt-cells	: Has to be 1
+
+For other required and optional properties of SPI slave nodes please refer to
+../spi/spi-bus.txt.
+
+Required properties of subnodes:
+ - reg			: Should be position on the Moxtet bus
+
+The driver finds the devices connected to the bus by itself, but it may be
+needed to reference some of them from other parts of the device tree. In that
+case the devices can be defined as subnodes of the moxtet node.
+
+Example:
+
+	moxtet@1 {
+		compatible = "cznic,moxtet";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <1>;
+		spi-max-frequency = <10000000>;
+		spi-cpol;
+		spi-cpha;
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		interrupt-parent = <&gpiosb>;
+		interrupts = <5 IRQ_TYPE_EDGE_FALLING>;
+
+		moxtet_sfp: gpio@0 {
+			compatible = "cznic,moxtet-sfp";
+			gpio-controller;
+			#gpio-cells = <2>;
+			reg = <0>;
+		}
+	};
diff --git a/MAINTAINERS b/MAINTAINERS
index d96d36c83bc3..3f461a2d776a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1502,6 +1502,7 @@ ARM/CZ.NIC TURRIS MOX SUPPORT
 M:	Marek Behun <marek.behun@nic.cz>
 W:	http://mox.turris.cz
 S:	Maintained
+F:	Documentation/devicetree/bindings/bus/moxtet.txt
 F:	include/linux/moxtet.h
 F:	drivers/bus/moxtet.c
 
-- 
2.19.2

[PATCH v4 armsoc/drivers/bus+gpio 2/5] dt-bindings: bus: Document moxtet bus binding

[Marek Behún]

This adds device tree binding documentation for the Moxtet bus, a bus
via which the different modules connected to the Turris Mox router can
be configured.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 .../devicetree/bindings/bus/moxtet.txt        | 44 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 45 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt

diff --git a/Documentation/devicetree/bindings/bus/moxtet.txt b/Documentation/devicetree/bindings/bus/moxtet.txt
new file mode 100644
index 000000000000..7be9d00c1767
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/moxtet.txt
@@ -0,0 +1,44 @@
+Turris Mox module status and configuration bus (over SPI)
+
+Required properties:
+ - compatible		: Should be "cznic,moxtet"
+ - #address-cells	: Has to be 1
+ - #size-cells		: Has to be 0
+ - spi-cpol		: Required inverted clock polarity
+ - spi-cpha		: Required shifted clock phase
+ - interrupts		: Must contain reference to the shared interrupt line
+ - interrupt-controller	: Required
+ - #interrupt-cells	: Has to be 1
+
+For other required and optional properties of SPI slave nodes please refer to
+../spi/spi-bus.txt.
+
+Required properties of subnodes:
+ - reg			: Should be position on the Moxtet bus
+
+The driver finds the devices connected to the bus by itself, but it may be
+needed to reference some of them from other parts of the device tree. In that
+case the devices can be defined as subnodes of the moxtet node.
+
+Example:
+
+	moxtet@1 {
+		compatible = "cznic,moxtet";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <1>;
+		spi-max-frequency = <10000000>;
+		spi-cpol;
+		spi-cpha;
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		interrupt-parent = <&gpiosb>;
+		interrupts = <5 IRQ_TYPE_EDGE_FALLING>;
+
+		moxtet_sfp: gpio@0 {
+			compatible = "cznic,moxtet-sfp";
+			gpio-controller;
+			#gpio-cells = <2>;
+			reg = <0>;
+		}
+	};
diff --git a/MAINTAINERS b/MAINTAINERS
index d96d36c83bc3..3f461a2d776a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1502,6 +1502,7 @@ ARM/CZ.NIC TURRIS MOX SUPPORT
 M:	Marek Behun <marek.behun@nic.cz>
 W:	http://mox.turris.cz
 S:	Maintained
+F:	Documentation/devicetree/bindings/bus/moxtet.txt
 F:	include/linux/moxtet.h
 F:	drivers/bus/moxtet.c
 
-- 
2.19.2


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Re: [PATCH v4 armsoc/drivers/bus+gpio 2/5] dt-bindings: bus: Document moxtet bus binding

[Rob Herring]

On Thu, Mar 07, 2019 at 01:52:48PM +0100, Marek Behún wrote:
> This adds device tree binding documentation for the Moxtet bus, a bus
> via which the different modules connected to the Turris Mox router can
> be configured.
> 
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  .../devicetree/bindings/bus/moxtet.txt        | 44 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 45 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt
> 
> diff --git a/Documentation/devicetree/bindings/bus/moxtet.txt b/Documentation/devicetree/bindings/bus/moxtet.txt
> new file mode 100644
> index 000000000000..7be9d00c1767
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/bus/moxtet.txt
> @@ -0,0 +1,44 @@
> +Turris Mox module status and configuration bus (over SPI)
> +
> +Required properties:
> + - compatible		: Should be "cznic,moxtet"
> + - #address-cells	: Has to be 1
> + - #size-cells		: Has to be 0
> + - spi-cpol		: Required inverted clock polarity
> + - spi-cpha		: Required shifted clock phase
> + - interrupts		: Must contain reference to the shared interrupt line
> + - interrupt-controller	: Required
> + - #interrupt-cells	: Has to be 1
> +
> +For other required and optional properties of SPI slave nodes please refer to
> +../spi/spi-bus.txt.
> +
> +Required properties of subnodes:
> + - reg			: Should be position on the Moxtet bus

'position' is a little vague.

> +
> +The driver finds the devices connected to the bus by itself, but it may be
> +needed to reference some of them from other parts of the device tree. In that
> +case the devices can be defined as subnodes of the moxtet node.
> +
> +Example:
> +
> +	moxtet@1 {
> +		compatible = "cznic,moxtet";
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		reg = <1>;
> +		spi-max-frequency = <10000000>;
> +		spi-cpol;
> +		spi-cpha;
> +		interrupt-controller;
> +		#interrupt-cells = <1>;
> +		interrupt-parent = <&gpiosb>;
> +		interrupts = <5 IRQ_TYPE_EDGE_FALLING>;
> +
> +		moxtet_sfp: gpio@0 {
> +			compatible = "cznic,moxtet-sfp";

cznic,moxtet-gpio according to the next patch.

> +			gpio-controller;
> +			#gpio-cells = <2>;
> +			reg = <0>;
> +		}
> +	};
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d96d36c83bc3..3f461a2d776a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1502,6 +1502,7 @@ ARM/CZ.NIC TURRIS MOX SUPPORT
>  M:	Marek Behun <marek.behun@nic.cz>
>  W:	http://mox.turris.cz
>  S:	Maintained
> +F:	Documentation/devicetree/bindings/bus/moxtet.txt
>  F:	include/linux/moxtet.h
>  F:	drivers/bus/moxtet.c
>  
> -- 
> 2.19.2
> 

Re: [PATCH v4 armsoc/drivers/bus+gpio 2/5] dt-bindings: bus: Document moxtet bus binding

[Rob Herring]

On Thu, Mar 07, 2019 at 01:52:48PM +0100, Marek Behún wrote:
> This adds device tree binding documentation for the Moxtet bus, a bus
> via which the different modules connected to the Turris Mox router can
> be configured.
> 
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  .../devicetree/bindings/bus/moxtet.txt        | 44 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 45 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt
> 
> diff --git a/Documentation/devicetree/bindings/bus/moxtet.txt b/Documentation/devicetree/bindings/bus/moxtet.txt
> new file mode 100644
> index 000000000000..7be9d00c1767
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/bus/moxtet.txt
> @@ -0,0 +1,44 @@
> +Turris Mox module status and configuration bus (over SPI)
> +
> +Required properties:
> + - compatible		: Should be "cznic,moxtet"
> + - #address-cells	: Has to be 1
> + - #size-cells		: Has to be 0
> + - spi-cpol		: Required inverted clock polarity
> + - spi-cpha		: Required shifted clock phase
> + - interrupts		: Must contain reference to the shared interrupt line
> + - interrupt-controller	: Required
> + - #interrupt-cells	: Has to be 1
> +
> +For other required and optional properties of SPI slave nodes please refer to
> +../spi/spi-bus.txt.
> +
> +Required properties of subnodes:
> + - reg			: Should be position on the Moxtet bus

'position' is a little vague.

> +
> +The driver finds the devices connected to the bus by itself, but it may be
> +needed to reference some of them from other parts of the device tree. In that
> +case the devices can be defined as subnodes of the moxtet node.
> +
> +Example:
> +
> +	moxtet@1 {
> +		compatible = "cznic,moxtet";
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		reg = <1>;
> +		spi-max-frequency = <10000000>;
> +		spi-cpol;
> +		spi-cpha;
> +		interrupt-controller;
> +		#interrupt-cells = <1>;
> +		interrupt-parent = <&gpiosb>;
> +		interrupts = <5 IRQ_TYPE_EDGE_FALLING>;
> +
> +		moxtet_sfp: gpio@0 {
> +			compatible = "cznic,moxtet-sfp";

cznic,moxtet-gpio according to the next patch.

> +			gpio-controller;
> +			#gpio-cells = <2>;
> +			reg = <0>;
> +		}
> +	};
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d96d36c83bc3..3f461a2d776a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1502,6 +1502,7 @@ ARM/CZ.NIC TURRIS MOX SUPPORT
>  M:	Marek Behun <marek.behun@nic.cz>
>  W:	http://mox.turris.cz
>  S:	Maintained
> +F:	Documentation/devicetree/bindings/bus/moxtet.txt
>  F:	include/linux/moxtet.h
>  F:	drivers/bus/moxtet.c
>  
> -- 
> 2.19.2
> 

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[PATCH v4.1 armsoc/drivers/bus+gpio 2/5] dt-bindings: bus: Document moxtet bus binding

[Marek Behún]

This adds device tree binding documentation for the Moxtet bus, a bus
via which the different modules connected to the Turris Mox router can
be configured.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 .../devicetree/bindings/bus/moxtet.txt        | 44 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 45 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt

diff --git a/Documentation/devicetree/bindings/bus/moxtet.txt b/Documentation/devicetree/bindings/bus/moxtet.txt
new file mode 100644
index 000000000000..7be9d00c1767
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/moxtet.txt
@@ -0,0 +1,46 @@
+Turris Mox module status and configuration bus (over SPI)
+
+Required properties:
+ - compatible		: Should be "cznic,moxtet"
+ - #address-cells	: Has to be 1
+ - #size-cells		: Has to be 0
+ - spi-cpol		: Required inverted clock polarity
+ - spi-cpha		: Required shifted clock phase
+ - interrupts		: Must contain reference to the shared interrupt line
+ - interrupt-controller	: Required
+ - #interrupt-cells	: Has to be 1
+
+For other required and optional properties of SPI slave nodes please refer to
+../spi/spi-bus.txt.
+
+Required properties of subnodes:
+ - reg			: Should be position on the Moxtet bus (how many Moxtet
+			  modules are between this module and CPU module, so
+			  either 0 or a positive integer)
+
+The driver finds the devices connected to the bus by itself, but it may be
+needed to reference some of them from other parts of the device tree. In that
+case the devices can be defined as subnodes of the moxtet node.
+
+Example:
+
+	moxtet@1 {
+		compatible = "cznic,moxtet";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <1>;
+		spi-max-frequency = <10000000>;
+		spi-cpol;
+		spi-cpha;
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		interrupt-parent = <&gpiosb>;
+		interrupts = <5 IRQ_TYPE_EDGE_FALLING>;
+
+		moxtet_sfp: gpio@0 {
+			compatible = "cznic,moxtet-gpio";
+			gpio-controller;
+			#gpio-cells = <2>;
+			reg = <0>;
+		}
+	};
diff --git a/MAINTAINERS b/MAINTAINERS
index d96d36c83bc3..3f461a2d776a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1502,6 +1502,7 @@ ARM/CZ.NIC TURRIS MOX SUPPORT
 M:	Marek Behun <marek.behun@nic.cz>
 W:	http://mox.turris.cz
 S:	Maintained
+F:	Documentation/devicetree/bindings/bus/moxtet.txt
 F:	include/linux/moxtet.h
 F:	drivers/bus/moxtet.c
 
-- 
2.19.2

[PATCH v4.1 armsoc/drivers/bus+gpio 2/5] dt-bindings: bus: Document moxtet bus binding

[Marek Behún]

This adds device tree binding documentation for the Moxtet bus, a bus
via which the different modules connected to the Turris Mox router can
be configured.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 .../devicetree/bindings/bus/moxtet.txt        | 44 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 45 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt

diff --git a/Documentation/devicetree/bindings/bus/moxtet.txt b/Documentation/devicetree/bindings/bus/moxtet.txt
new file mode 100644
index 000000000000..7be9d00c1767
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/moxtet.txt
@@ -0,0 +1,46 @@
+Turris Mox module status and configuration bus (over SPI)
+
+Required properties:
+ - compatible		: Should be "cznic,moxtet"
+ - #address-cells	: Has to be 1
+ - #size-cells		: Has to be 0
+ - spi-cpol		: Required inverted clock polarity
+ - spi-cpha		: Required shifted clock phase
+ - interrupts		: Must contain reference to the shared interrupt line
+ - interrupt-controller	: Required
+ - #interrupt-cells	: Has to be 1
+
+For other required and optional properties of SPI slave nodes please refer to
+../spi/spi-bus.txt.
+
+Required properties of subnodes:
+ - reg			: Should be position on the Moxtet bus (how many Moxtet
+			  modules are between this module and CPU module, so
+			  either 0 or a positive integer)
+
+The driver finds the devices connected to the bus by itself, but it may be
+needed to reference some of them from other parts of the device tree. In that
+case the devices can be defined as subnodes of the moxtet node.
+
+Example:
+
+	moxtet@1 {
+		compatible = "cznic,moxtet";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <1>;
+		spi-max-frequency = <10000000>;
+		spi-cpol;
+		spi-cpha;
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		interrupt-parent = <&gpiosb>;
+		interrupts = <5 IRQ_TYPE_EDGE_FALLING>;
+
+		moxtet_sfp: gpio@0 {
+			compatible = "cznic,moxtet-gpio";
+			gpio-controller;
+			#gpio-cells = <2>;
+			reg = <0>;
+		}
+	};
diff --git a/MAINTAINERS b/MAINTAINERS
index d96d36c83bc3..3f461a2d776a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1502,6 +1502,7 @@ ARM/CZ.NIC TURRIS MOX SUPPORT
 M:	Marek Behun <marek.behun@nic.cz>
 W:	http://mox.turris.cz
 S:	Maintained
+F:	Documentation/devicetree/bindings/bus/moxtet.txt
 F:	include/linux/moxtet.h
 F:	drivers/bus/moxtet.c
 
-- 
2.19.2


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Re: [PATCH v4.1 armsoc/drivers/bus+gpio 2/5] dt-bindings: bus: Document moxtet bus binding

[Rob Herring]

On Thu, 14 Mar 2019 16:01:35 +0100, =?UTF-8?q?Marek=20Beh=C3=BAn?= wrote:
> This adds device tree binding documentation for the Moxtet bus, a bus
> via which the different modules connected to the Turris Mox router can
> be configured.
> 
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  .../devicetree/bindings/bus/moxtet.txt        | 44 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 45 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt
> 

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

Re: [PATCH v4.1 armsoc/drivers/bus+gpio 2/5] dt-bindings: bus: Document moxtet bus binding

[Rob Herring]

On Thu, 14 Mar 2019 16:01:35 +0100, =?UTF-8?q?Marek=20Beh=C3=BAn?= wrote:
> This adds device tree binding documentation for the Moxtet bus, a bus
> via which the different modules connected to the Turris Mox router can
> be configured.
> 
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  .../devicetree/bindings/bus/moxtet.txt        | 44 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 45 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt
> 

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

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Re: [PATCH v4.1 armsoc/drivers/bus+gpio 2/5] dt-bindings: bus: Document moxtet bus binding

[Rob Herring]

On Thu, 14 Mar 2019 16:01:35 +0100, =?UTF-8?q?Marek=20Beh=C3=BAn?= wrote:
> This adds device tree binding documentation for the Moxtet bus, a bus
> via which the different modules connected to the Turris Mox router can
> be configured.
> 
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  .../devicetree/bindings/bus/moxtet.txt        | 44 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 45 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt
> 

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

[PATCH v4 armsoc/drivers/bus+gpio 3/5] bus: moxtet: Add sysfs and debugfs documentation

[Marek Behún]

Add sysfs ABI documentation for the attribute files module_id and
module_name

Add debugfs ABI documentation for reading input from the shift registers
and reading last written output or write output to the shift registers.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
 Documentation/ABI/testing/debugfs-moxtet      | 23 +++++++++++++++++++
 .../ABI/testing/sysfs-bus-moxtet-devices      | 17 ++++++++++++++
 MAINTAINERS                                   |  2 ++
 3 files changed, 42 insertions(+)
 create mode 100644 Documentation/ABI/testing/debugfs-moxtet
 create mode 100644 Documentation/ABI/testing/sysfs-bus-moxtet-devices

diff --git a/Documentation/ABI/testing/debugfs-moxtet b/Documentation/ABI/testing/debugfs-moxtet
new file mode 100644
index 000000000000..32a02e7d0f4e
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-moxtet
@@ -0,0 +1,23 @@
+What:		/sys/kernel/debug/moxtet/input
+Date:		March 2019
+KernelVersion:	5.2
+Contact:	Marek Behún <marek.behun@nic.cz>
+Description:	(R) Read input from the shift registers, in hexadecimal.
+		Returns N+1 bytes, where N is the number of Moxtet connected
+		modules. The first byte is from the CPU board itself.
+		Example: 101214
+			 10: CPU board with SD card
+			 12: 2 = PCIe module, 1 = IRQ not active
+			 14: 4 = Peridot module, 1 = IRQ not active
+
+What:		/sys/kernel/debug/moxtet/output
+Date:		March 2019
+KernelVersion:	5.2
+Contact:	Marek Behún <marek.behun@nic.cz>
+Description:	(RW) Read last written value to the shift registers, in
+		hexadecimal, or write values to the shift registers, also
+		in hexadecimal.
+		Example: 0102
+			 01: 01 was last written, or is to be written, to the
+			     first module's shift register
+			 02: the same for second module
diff --git a/Documentation/ABI/testing/sysfs-bus-moxtet-devices b/Documentation/ABI/testing/sysfs-bus-moxtet-devices
new file mode 100644
index 000000000000..3e3256b37a3c
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-moxtet-devices
@@ -0,0 +1,17 @@
+What:		/sys/bus/moxtet/devices/moxtet-<name>.<addr>/module_description
+Date:		March 2019
+KernelVersion:	5.2
+Contact:	Marek Behún <marek.behun@nic.cz>
+Description:	(R) Moxtet module description. Format: string
+
+What:		/sys/bus/moxtet/devices/moxtet-<name>.<addr>/module_id
+Date:		March 2019
+KernelVersion:	5.2
+Contact:	Marek Behún <marek.behun@nic.cz>
+Description:	(R) Moxtet module ID. Format: %x
+
+What:		/sys/bus/moxtet/devices/moxtet-<name>.<addr>/module_name
+Date:		March 2019
+KernelVersion:	5.2
+Contact:	Marek Behún <marek.behun@nic.cz>
+Description:	(R) Moxtet module name. Format: string
diff --git a/MAINTAINERS b/MAINTAINERS
index 3f461a2d776a..43de8eaa284b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1502,6 +1502,8 @@ ARM/CZ.NIC TURRIS MOX SUPPORT
 M:	Marek Behun <marek.behun@nic.cz>
 W:	http://mox.turris.cz
 S:	Maintained
+F:	Documentation/ABI/testing/debugfs-moxtet
+F:	Documentation/ABI/testing/sysfs-bus-moxtet-devices
 F:	Documentation/devicetree/bindings/bus/moxtet.txt
 F:	include/linux/moxtet.h
 F:	drivers/bus/moxtet.c
-- 
2.19.2

[PATCH v4 armsoc/drivers/bus+gpio 3/5] bus: moxtet: Add sysfs and debugfs documentation

[Marek Behún]

Add sysfs ABI documentation for the attribute files module_id and
module_name

Add debugfs ABI documentation for reading input from the shift registers
and reading last written output or write output to the shift registers.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
 Documentation/ABI/testing/debugfs-moxtet      | 23 +++++++++++++++++++
 .../ABI/testing/sysfs-bus-moxtet-devices      | 17 ++++++++++++++
 MAINTAINERS                                   |  2 ++
 3 files changed, 42 insertions(+)
 create mode 100644 Documentation/ABI/testing/debugfs-moxtet
 create mode 100644 Documentation/ABI/testing/sysfs-bus-moxtet-devices

diff --git a/Documentation/ABI/testing/debugfs-moxtet b/Documentation/ABI/testing/debugfs-moxtet
new file mode 100644
index 000000000000..32a02e7d0f4e
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-moxtet
@@ -0,0 +1,23 @@
+What:		/sys/kernel/debug/moxtet/input
+Date:		March 2019
+KernelVersion:	5.2
+Contact:	Marek Behún <marek.behun@nic.cz>
+Description:	(R) Read input from the shift registers, in hexadecimal.
+		Returns N+1 bytes, where N is the number of Moxtet connected
+		modules. The first byte is from the CPU board itself.
+		Example: 101214
+			 10: CPU board with SD card
+			 12: 2 = PCIe module, 1 = IRQ not active
+			 14: 4 = Peridot module, 1 = IRQ not active
+
+What:		/sys/kernel/debug/moxtet/output
+Date:		March 2019
+KernelVersion:	5.2
+Contact:	Marek Behún <marek.behun@nic.cz>
+Description:	(RW) Read last written value to the shift registers, in
+		hexadecimal, or write values to the shift registers, also
+		in hexadecimal.
+		Example: 0102
+			 01: 01 was last written, or is to be written, to the
+			     first module's shift register
+			 02: the same for second module
diff --git a/Documentation/ABI/testing/sysfs-bus-moxtet-devices b/Documentation/ABI/testing/sysfs-bus-moxtet-devices
new file mode 100644
index 000000000000..3e3256b37a3c
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-moxtet-devices
@@ -0,0 +1,17 @@
+What:		/sys/bus/moxtet/devices/moxtet-<name>.<addr>/module_description
+Date:		March 2019
+KernelVersion:	5.2
+Contact:	Marek Behún <marek.behun@nic.cz>
+Description:	(R) Moxtet module description. Format: string
+
+What:		/sys/bus/moxtet/devices/moxtet-<name>.<addr>/module_id
+Date:		March 2019
+KernelVersion:	5.2
+Contact:	Marek Behún <marek.behun@nic.cz>
+Description:	(R) Moxtet module ID. Format: %x
+
+What:		/sys/bus/moxtet/devices/moxtet-<name>.<addr>/module_name
+Date:		March 2019
+KernelVersion:	5.2
+Contact:	Marek Behún <marek.behun@nic.cz>
+Description:	(R) Moxtet module name. Format: string
diff --git a/MAINTAINERS b/MAINTAINERS
index 3f461a2d776a..43de8eaa284b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1502,6 +1502,8 @@ ARM/CZ.NIC TURRIS MOX SUPPORT
 M:	Marek Behun <marek.behun@nic.cz>
 W:	http://mox.turris.cz
 S:	Maintained
+F:	Documentation/ABI/testing/debugfs-moxtet
+F:	Documentation/ABI/testing/sysfs-bus-moxtet-devices
 F:	Documentation/devicetree/bindings/bus/moxtet.txt
 F:	include/linux/moxtet.h
 F:	drivers/bus/moxtet.c
-- 
2.19.2


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Re: [PATCH v4 armsoc/drivers/bus+gpio 3/5] bus: moxtet: Add sysfs and debugfs documentation

[Linus Walleij]

On Thu, Mar 7, 2019 at 1:53 PM Marek Behún <marek.behun@nic.cz> wrote:

> Add sysfs ABI documentation for the attribute files module_id and
> module_name
>
> Add debugfs ABI documentation for reading input from the shift registers
> and reading last written output or write output to the shift registers.
>
> Signed-off-by: Marek Behún <marek.behun@nic.cz>

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

Yours,
Linus Walleij

Re: [PATCH v4 armsoc/drivers/bus+gpio 3/5] bus: moxtet: Add sysfs and debugfs documentation

[Linus Walleij]

On Thu, Mar 7, 2019 at 1:53 PM Marek Behún <marek.behun@nic.cz> wrote:

> Add sysfs ABI documentation for the attribute files module_id and
> module_name
>
> Add debugfs ABI documentation for reading input from the shift registers
> and reading last written output or write output to the shift registers.
>
> Signed-off-by: Marek Behún <marek.behun@nic.cz>

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

Yours,
Linus Walleij

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[PATCH v4 armsoc/drivers/bus+gpio 4/5] drivers: gpio: Add support for GPIOs over Moxtet bus

[Marek Behún]

This adds support for interpreting the input and output bits of one
device on Moxtet bus as GPIOs.
This is needed for example by the SFP cage module of Turris Mox.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 MAINTAINERS                |   1 +
 drivers/gpio/Kconfig       |   9 ++
 drivers/gpio/Makefile      |   1 +
 drivers/gpio/gpio-moxtet.c | 179 +++++++++++++++++++++++++++++++++++++
 4 files changed, 190 insertions(+)
 create mode 100644 drivers/gpio/gpio-moxtet.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 43de8eaa284b..6af384154ce5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1507,6 +1507,7 @@ F:	Documentation/ABI/testing/sysfs-bus-moxtet-devices
 F:	Documentation/devicetree/bindings/bus/moxtet.txt
 F:	include/linux/moxtet.h
 F:	drivers/bus/moxtet.c
+F:	drivers/gpio/gpio-moxtet.c
 
 ARM/EBSA110 MACHINE SUPPORT
 M:	Russell King <linux@armlinux.org.uk>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b5a2845347ec..2c9ffa0e2287 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1400,6 +1400,15 @@ config GPIO_XRA1403
 	help
 	  GPIO driver for EXAR XRA1403 16-bit SPI-based GPIO expander.
 
+config GPIO_MOXTET
+	tristate "Turris Mox Moxtet bus GPIO expander"
+	depends on MOXTET
+	help
+	  Say yes here if you are building for the Turris Mox router.
+	  This is the driver needed for configuring the GPIOs via the Moxtet
+	  bus. For example the Mox module with SFP cage needs this driver
+	  so that phylink can use corresponding GPIOs.
+
 endmenu
 
 menu "USB GPIO expanders"
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 37628f8dbf70..3d0b28cbf62c 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -86,6 +86,7 @@ obj-$(CONFIG_GPIO_MC9S08DZ60)	+= gpio-mc9s08dz60.o
 obj-$(CONFIG_GPIO_ML_IOH)	+= gpio-ml-ioh.o
 obj-$(CONFIG_GPIO_MM_LANTIQ)	+= gpio-mm-lantiq.o
 obj-$(CONFIG_GPIO_MOCKUP)      += gpio-mockup.o
+obj-$(CONFIG_GPIO_MOXTET)	+= gpio-moxtet.o
 obj-$(CONFIG_GPIO_MPC5200)	+= gpio-mpc5200.o
 obj-$(CONFIG_GPIO_MPC8XXX)	+= gpio-mpc8xxx.o
 obj-$(CONFIG_GPIO_MSIC)		+= gpio-msic.o
diff --git a/drivers/gpio/gpio-moxtet.c b/drivers/gpio/gpio-moxtet.c
new file mode 100644
index 000000000000..3fd729994a38
--- /dev/null
+++ b/drivers/gpio/gpio-moxtet.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Turris Mox Moxtet GPIO expander
+ *
+ *  Copyright (C) 2018 Marek Behun <marek.behun@nic.cz>
+ */
+
+#include <linux/bitops.h>
+#include <linux/gpio/driver.h>
+#include <linux/moxtet.h>
+#include <linux/module.h>
+
+#define MOXTET_GPIO_NGPIOS	12
+#define MOXTET_GPIO_INPUTS	4
+
+struct moxtet_gpio_desc {
+	u16 in_mask;
+	u16 out_mask;
+};
+
+static const struct moxtet_gpio_desc descs[] = {
+	[TURRIS_MOX_MODULE_SFP] = {
+		.in_mask = GENMASK(2, 0),
+		.out_mask = GENMASK(5, 4),
+	},
+};
+
+struct moxtet_gpio_chip {
+	struct device			*dev;
+	struct gpio_chip		gpio_chip;
+	const struct moxtet_gpio_desc	*desc;
+};
+
+static int moxtet_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
+{
+	struct moxtet_gpio_chip *chip = gpiochip_get_data(gc);
+	int ret;
+
+	if (chip->desc->in_mask & BIT(offset)) {
+		ret = moxtet_device_read(chip->dev);
+	} else if (chip->desc->out_mask & BIT(offset)) {
+		ret = moxtet_device_written(chip->dev);
+		if (ret >= 0)
+			ret <<= MOXTET_GPIO_INPUTS;
+	} else {
+		return -EINVAL;
+	}
+
+	if (ret < 0)
+		return ret;
+
+	return !!(ret & BIT(offset));
+}
+
+static void moxtet_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
+				  int val)
+{
+	struct moxtet_gpio_chip *chip = gpiochip_get_data(gc);
+	int state;
+
+	state = moxtet_device_written(chip->dev);
+	if (state < 0)
+		return;
+
+	offset -= MOXTET_GPIO_INPUTS;
+
+	if (val)
+		state |= BIT(offset);
+	else
+		state &= ~BIT(offset);
+
+	moxtet_device_write(chip->dev, state);
+}
+
+static int moxtet_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	struct moxtet_gpio_chip *chip = gpiochip_get_data(gc);
+
+	/* All lines are hard wired to be either input or output, not both. */
+	if (chip->desc->in_mask & BIT(offset))
+		return 1;
+	else if (chip->desc->out_mask & BIT(offset))
+		return 0;
+	else
+		return -EINVAL;
+}
+
+static int moxtet_gpio_direction_input(struct gpio_chip *gc,
+				       unsigned int offset)
+{
+	struct moxtet_gpio_chip *chip = gpiochip_get_data(gc);
+
+	if (chip->desc->in_mask & BIT(offset))
+		return 0;
+	else if (chip->desc->out_mask & BIT(offset))
+		return -ENOTSUPP;
+	else
+		return -EINVAL;
+}
+
+static int moxtet_gpio_direction_output(struct gpio_chip *gc,
+					unsigned int offset, int val)
+{
+	struct moxtet_gpio_chip *chip = gpiochip_get_data(gc);
+
+	if (chip->desc->out_mask & BIT(offset))
+		moxtet_gpio_set_value(gc, offset, val);
+	else if (chip->desc->in_mask & BIT(offset))
+		return -ENOTSUPP;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+static int moxtet_gpio_probe(struct device *dev)
+{
+	struct moxtet_gpio_chip *chip;
+	struct device_node *nc = dev->of_node;
+	int id;
+
+	id = to_moxtet_device(dev)->id;
+
+	if (id >= ARRAY_SIZE(descs)) {
+		dev_err(dev, "%pOF Moxtet device id 0x%x is not supported by gpio-moxtet driver\n",
+			nc, id);
+		return -ENOTSUPP;
+	}
+
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->dev = dev;
+	chip->gpio_chip.parent = dev;
+	chip->desc = &descs[id];
+
+	dev_set_drvdata(dev, chip);
+
+	chip->gpio_chip.label = dev_name(dev);
+	chip->gpio_chip.get_direction = moxtet_gpio_get_direction;
+	chip->gpio_chip.direction_input = moxtet_gpio_direction_input;
+	chip->gpio_chip.direction_output = moxtet_gpio_direction_output;
+	chip->gpio_chip.get = moxtet_gpio_get_value;
+	chip->gpio_chip.set = moxtet_gpio_set_value;
+	chip->gpio_chip.base = -1;
+
+	chip->gpio_chip.ngpio = MOXTET_GPIO_NGPIOS;
+
+	chip->gpio_chip.can_sleep = true;
+	chip->gpio_chip.owner = THIS_MODULE;
+
+	return devm_gpiochip_add_data(dev, &chip->gpio_chip, chip);
+}
+
+static const struct of_device_id moxtet_gpio_dt_ids[] = {
+	{ .compatible = "cznic,moxtet-gpio", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, moxtet_gpio_dt_ids);
+
+static const enum turris_mox_module_id moxtet_gpio_module_table[] = {
+	TURRIS_MOX_MODULE_SFP,
+	0,
+};
+
+static struct moxtet_driver moxtet_gpio_driver = {
+	.driver = {
+		.name		= "moxtet-gpio",
+		.of_match_table	= moxtet_gpio_dt_ids,
+		.probe		= moxtet_gpio_probe,
+	},
+	.id_table = moxtet_gpio_module_table,
+};
+module_moxtet_driver(moxtet_gpio_driver);
+
+MODULE_AUTHOR("Marek Behun <marek.behun@nic.cz>");
+MODULE_DESCRIPTION("Turris Mox Moxtet GPIO expander");
+MODULE_LICENSE("GPL v2");
-- 
2.19.2

[PATCH v4 armsoc/drivers/bus+gpio 4/5] drivers: gpio: Add support for GPIOs over Moxtet bus

[Marek Behún]

This adds support for interpreting the input and output bits of one
device on Moxtet bus as GPIOs.
This is needed for example by the SFP cage module of Turris Mox.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 MAINTAINERS                |   1 +
 drivers/gpio/Kconfig       |   9 ++
 drivers/gpio/Makefile      |   1 +
 drivers/gpio/gpio-moxtet.c | 179 +++++++++++++++++++++++++++++++++++++
 4 files changed, 190 insertions(+)
 create mode 100644 drivers/gpio/gpio-moxtet.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 43de8eaa284b..6af384154ce5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1507,6 +1507,7 @@ F:	Documentation/ABI/testing/sysfs-bus-moxtet-devices
 F:	Documentation/devicetree/bindings/bus/moxtet.txt
 F:	include/linux/moxtet.h
 F:	drivers/bus/moxtet.c
+F:	drivers/gpio/gpio-moxtet.c
 
 ARM/EBSA110 MACHINE SUPPORT
 M:	Russell King <linux@armlinux.org.uk>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b5a2845347ec..2c9ffa0e2287 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1400,6 +1400,15 @@ config GPIO_XRA1403
 	help
 	  GPIO driver for EXAR XRA1403 16-bit SPI-based GPIO expander.
 
+config GPIO_MOXTET
+	tristate "Turris Mox Moxtet bus GPIO expander"
+	depends on MOXTET
+	help
+	  Say yes here if you are building for the Turris Mox router.
+	  This is the driver needed for configuring the GPIOs via the Moxtet
+	  bus. For example the Mox module with SFP cage needs this driver
+	  so that phylink can use corresponding GPIOs.
+
 endmenu
 
 menu "USB GPIO expanders"
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 37628f8dbf70..3d0b28cbf62c 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -86,6 +86,7 @@ obj-$(CONFIG_GPIO_MC9S08DZ60)	+= gpio-mc9s08dz60.o
 obj-$(CONFIG_GPIO_ML_IOH)	+= gpio-ml-ioh.o
 obj-$(CONFIG_GPIO_MM_LANTIQ)	+= gpio-mm-lantiq.o
 obj-$(CONFIG_GPIO_MOCKUP)      += gpio-mockup.o
+obj-$(CONFIG_GPIO_MOXTET)	+= gpio-moxtet.o
 obj-$(CONFIG_GPIO_MPC5200)	+= gpio-mpc5200.o
 obj-$(CONFIG_GPIO_MPC8XXX)	+= gpio-mpc8xxx.o
 obj-$(CONFIG_GPIO_MSIC)		+= gpio-msic.o
diff --git a/drivers/gpio/gpio-moxtet.c b/drivers/gpio/gpio-moxtet.c
new file mode 100644
index 000000000000..3fd729994a38
--- /dev/null
+++ b/drivers/gpio/gpio-moxtet.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Turris Mox Moxtet GPIO expander
+ *
+ *  Copyright (C) 2018 Marek Behun <marek.behun@nic.cz>
+ */
+
+#include <linux/bitops.h>
+#include <linux/gpio/driver.h>
+#include <linux/moxtet.h>
+#include <linux/module.h>
+
+#define MOXTET_GPIO_NGPIOS	12
+#define MOXTET_GPIO_INPUTS	4
+
+struct moxtet_gpio_desc {
+	u16 in_mask;
+	u16 out_mask;
+};
+
+static const struct moxtet_gpio_desc descs[] = {
+	[TURRIS_MOX_MODULE_SFP] = {
+		.in_mask = GENMASK(2, 0),
+		.out_mask = GENMASK(5, 4),
+	},
+};
+
+struct moxtet_gpio_chip {
+	struct device			*dev;
+	struct gpio_chip		gpio_chip;
+	const struct moxtet_gpio_desc	*desc;
+};
+
+static int moxtet_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
+{
+	struct moxtet_gpio_chip *chip = gpiochip_get_data(gc);
+	int ret;
+
+	if (chip->desc->in_mask & BIT(offset)) {
+		ret = moxtet_device_read(chip->dev);
+	} else if (chip->desc->out_mask & BIT(offset)) {
+		ret = moxtet_device_written(chip->dev);
+		if (ret >= 0)
+			ret <<= MOXTET_GPIO_INPUTS;
+	} else {
+		return -EINVAL;
+	}
+
+	if (ret < 0)
+		return ret;
+
+	return !!(ret & BIT(offset));
+}
+
+static void moxtet_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
+				  int val)
+{
+	struct moxtet_gpio_chip *chip = gpiochip_get_data(gc);
+	int state;
+
+	state = moxtet_device_written(chip->dev);
+	if (state < 0)
+		return;
+
+	offset -= MOXTET_GPIO_INPUTS;
+
+	if (val)
+		state |= BIT(offset);
+	else
+		state &= ~BIT(offset);
+
+	moxtet_device_write(chip->dev, state);
+}
+
+static int moxtet_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	struct moxtet_gpio_chip *chip = gpiochip_get_data(gc);
+
+	/* All lines are hard wired to be either input or output, not both. */
+	if (chip->desc->in_mask & BIT(offset))
+		return 1;
+	else if (chip->desc->out_mask & BIT(offset))
+		return 0;
+	else
+		return -EINVAL;
+}
+
+static int moxtet_gpio_direction_input(struct gpio_chip *gc,
+				       unsigned int offset)
+{
+	struct moxtet_gpio_chip *chip = gpiochip_get_data(gc);
+
+	if (chip->desc->in_mask & BIT(offset))
+		return 0;
+	else if (chip->desc->out_mask & BIT(offset))
+		return -ENOTSUPP;
+	else
+		return -EINVAL;
+}
+
+static int moxtet_gpio_direction_output(struct gpio_chip *gc,
+					unsigned int offset, int val)
+{
+	struct moxtet_gpio_chip *chip = gpiochip_get_data(gc);
+
+	if (chip->desc->out_mask & BIT(offset))
+		moxtet_gpio_set_value(gc, offset, val);
+	else if (chip->desc->in_mask & BIT(offset))
+		return -ENOTSUPP;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+static int moxtet_gpio_probe(struct device *dev)
+{
+	struct moxtet_gpio_chip *chip;
+	struct device_node *nc = dev->of_node;
+	int id;
+
+	id = to_moxtet_device(dev)->id;
+
+	if (id >= ARRAY_SIZE(descs)) {
+		dev_err(dev, "%pOF Moxtet device id 0x%x is not supported by gpio-moxtet driver\n",
+			nc, id);
+		return -ENOTSUPP;
+	}
+
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->dev = dev;
+	chip->gpio_chip.parent = dev;
+	chip->desc = &descs[id];
+
+	dev_set_drvdata(dev, chip);
+
+	chip->gpio_chip.label = dev_name(dev);
+	chip->gpio_chip.get_direction = moxtet_gpio_get_direction;
+	chip->gpio_chip.direction_input = moxtet_gpio_direction_input;
+	chip->gpio_chip.direction_output = moxtet_gpio_direction_output;
+	chip->gpio_chip.get = moxtet_gpio_get_value;
+	chip->gpio_chip.set = moxtet_gpio_set_value;
+	chip->gpio_chip.base = -1;
+
+	chip->gpio_chip.ngpio = MOXTET_GPIO_NGPIOS;
+
+	chip->gpio_chip.can_sleep = true;
+	chip->gpio_chip.owner = THIS_MODULE;
+
+	return devm_gpiochip_add_data(dev, &chip->gpio_chip, chip);
+}
+
+static const struct of_device_id moxtet_gpio_dt_ids[] = {
+	{ .compatible = "cznic,moxtet-gpio", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, moxtet_gpio_dt_ids);
+
+static const enum turris_mox_module_id moxtet_gpio_module_table[] = {
+	TURRIS_MOX_MODULE_SFP,
+	0,
+};
+
+static struct moxtet_driver moxtet_gpio_driver = {
+	.driver = {
+		.name		= "moxtet-gpio",
+		.of_match_table	= moxtet_gpio_dt_ids,
+		.probe		= moxtet_gpio_probe,
+	},
+	.id_table = moxtet_gpio_module_table,
+};
+module_moxtet_driver(moxtet_gpio_driver);
+
+MODULE_AUTHOR("Marek Behun <marek.behun@nic.cz>");
+MODULE_DESCRIPTION("Turris Mox Moxtet GPIO expander");
+MODULE_LICENSE("GPL v2");
-- 
2.19.2


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[PATCH v4 armsoc/drivers/bus+gpio 5/5] dt-bindings: gpio: Document GPIOs via Moxtet bus

[Marek Behún]

This patch adds documentation of the device tree bindings for GPIOs
on the devices connected via Moxtet bus.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 .../devicetree/bindings/gpio/gpio-moxtet.txt   | 18 ++++++++++++++++++
 MAINTAINERS                                    |  1 +
 2 files changed, 19 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-moxtet.txt

diff --git a/Documentation/devicetree/bindings/gpio/gpio-moxtet.txt b/Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
new file mode 100644
index 000000000000..410759de9f09
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
@@ -0,0 +1,18 @@
+Turris Mox Moxtet GPIO expander via Moxtet bus
+
+Required properties:
+ - compatible		: Should be "cznic,moxtet-gpio".
+ - gpio-controller	: Marks the device node as a GPIO controller.
+ - #gpio-cells		: Should be two. For consumer use see gpio.txt.
+
+Other properties are required for a Moxtet bus device, please refer to
+Documentation/devicetree/bindings/bus/moxtet.txt.
+
+Example:
+
+	moxtet_sfp: gpio@0 {
+		compatible = "cznic,moxtet-gpio";
+		gpio-controller;
+		#gpio-cells = <2>;
+		reg = <0>;
+	}
diff --git a/MAINTAINERS b/MAINTAINERS
index 6af384154ce5..ccb979f64431 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1505,6 +1505,7 @@ S:	Maintained
 F:	Documentation/ABI/testing/debugfs-moxtet
 F:	Documentation/ABI/testing/sysfs-bus-moxtet-devices
 F:	Documentation/devicetree/bindings/bus/moxtet.txt
+F:	Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
 F:	include/linux/moxtet.h
 F:	drivers/bus/moxtet.c
 F:	drivers/gpio/gpio-moxtet.c
-- 
2.19.2

[PATCH v4 armsoc/drivers/bus+gpio 5/5] dt-bindings: gpio: Document GPIOs via Moxtet bus

[Marek Behún]

This patch adds documentation of the device tree bindings for GPIOs
on the devices connected via Moxtet bus.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 .../devicetree/bindings/gpio/gpio-moxtet.txt   | 18 ++++++++++++++++++
 MAINTAINERS                                    |  1 +
 2 files changed, 19 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-moxtet.txt

diff --git a/Documentation/devicetree/bindings/gpio/gpio-moxtet.txt b/Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
new file mode 100644
index 000000000000..410759de9f09
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
@@ -0,0 +1,18 @@
+Turris Mox Moxtet GPIO expander via Moxtet bus
+
+Required properties:
+ - compatible		: Should be "cznic,moxtet-gpio".
+ - gpio-controller	: Marks the device node as a GPIO controller.
+ - #gpio-cells		: Should be two. For consumer use see gpio.txt.
+
+Other properties are required for a Moxtet bus device, please refer to
+Documentation/devicetree/bindings/bus/moxtet.txt.
+
+Example:
+
+	moxtet_sfp: gpio@0 {
+		compatible = "cznic,moxtet-gpio";
+		gpio-controller;
+		#gpio-cells = <2>;
+		reg = <0>;
+	}
diff --git a/MAINTAINERS b/MAINTAINERS
index 6af384154ce5..ccb979f64431 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1505,6 +1505,7 @@ S:	Maintained
 F:	Documentation/ABI/testing/debugfs-moxtet
 F:	Documentation/ABI/testing/sysfs-bus-moxtet-devices
 F:	Documentation/devicetree/bindings/bus/moxtet.txt
+F:	Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
 F:	include/linux/moxtet.h
 F:	drivers/bus/moxtet.c
 F:	drivers/gpio/gpio-moxtet.c
-- 
2.19.2


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Re: [PATCH v4 armsoc/drivers/bus+gpio 5/5] dt-bindings: gpio: Document GPIOs via Moxtet bus

[Linus Walleij]

On Thu, Mar 7, 2019 at 1:53 PM Marek Behún <marek.behun@nic.cz> wrote:

> This patch adds documentation of the device tree bindings for GPIOs
> on the devices connected via Moxtet bus.
>
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org

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

Yours,
Linus Walleij

Re: [PATCH v4 armsoc/drivers/bus+gpio 5/5] dt-bindings: gpio: Document GPIOs via Moxtet bus

[Linus Walleij]

On Thu, Mar 7, 2019 at 1:53 PM Marek Behún <marek.behun@nic.cz> wrote:

> This patch adds documentation of the device tree bindings for GPIOs
> on the devices connected via Moxtet bus.
>
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org

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

Yours,
Linus Walleij

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Re: [PATCH v4 armsoc/drivers/bus+gpio 5/5] dt-bindings: gpio: Document GPIOs via Moxtet bus

[Linus Walleij]

On Thu, Mar 7, 2019 at 1:53 PM Marek Behún <marek.behun@nic.cz> wrote:

> This patch adds documentation of the device tree bindings for GPIOs
> on the devices connected via Moxtet bus.
>
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org

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

Yours,
Linus Walleij

Re: [PATCH v4 armsoc/drivers/bus+gpio 5/5] dt-bindings: gpio: Document GPIOs via Moxtet bus

[Rob Herring]

On Thu,  7 Mar 2019 13:52:51 +0100, =?UTF-8?q?Marek=20Beh=C3=BAn?= wrote:
> This patch adds documentation of the device tree bindings for GPIOs
> on the devices connected via Moxtet bus.
> 
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  .../devicetree/bindings/gpio/gpio-moxtet.txt   | 18 ++++++++++++++++++
>  MAINTAINERS                                    |  1 +
>  2 files changed, 19 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
> 

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

Re: [PATCH v4 armsoc/drivers/bus+gpio 5/5] dt-bindings: gpio: Document GPIOs via Moxtet bus

[Rob Herring]

On Thu,  7 Mar 2019 13:52:51 +0100, =?UTF-8?q?Marek=20Beh=C3=BAn?= wrote:
> This patch adds documentation of the device tree bindings for GPIOs
> on the devices connected via Moxtet bus.
> 
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  .../devicetree/bindings/gpio/gpio-moxtet.txt   | 18 ++++++++++++++++++
>  MAINTAINERS                                    |  1 +
>  2 files changed, 19 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
> 

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

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Re: [PATCH v4 armsoc/drivers/bus+gpio 5/5] dt-bindings: gpio: Document GPIOs via Moxtet bus

[Rob Herring]

On Thu,  7 Mar 2019 13:52:51 +0100, =?UTF-8?q?Marek=20Beh=C3=BAn?= wrote:
> This patch adds documentation of the device tree bindings for GPIOs
> on the devices connected via Moxtet bus.
> 
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  .../devicetree/bindings/gpio/gpio-moxtet.txt   | 18 ++++++++++++++++++
>  MAINTAINERS                                    |  1 +
>  2 files changed, 19 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
> 

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