path: root/drivers/bus/moxtet.c

// 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;
}

static struct bus_type moxtet_bus_type = {
	.name		= "moxtet",
	.dev_groups	= moxtet_dev_groups,
	.match		= moxtet_match,
};

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