OpenCloudOS-Kernel/drivers/bus/moxtet.c

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bus: Add support for Moxtet bus 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. Link: https://lore.kernel.org/r/20190812161118.21476-2-marek.behun@nic.cz Signed-off-by: Marek Behún <marek.behun@nic.cz> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-08-13 00:11:14 +08:00
// 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(bin) * 2 + 1];
bus: Add support for Moxtet bus 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. Link: https://lore.kernel.org/r/20190812161118.21476-2-marek.behun@nic.cz Signed-off-by: Marek Behún <marek.behun@nic.cz> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-08-13 00:11:14 +08:00
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];
ssize_t res;
bus: Add support for Moxtet bus 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. Link: https://lore.kernel.org/r/20190812161118.21476-2-marek.behun@nic.cz Signed-off-by: Marek Behún <marek.behun@nic.cz> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-08-13 00:11:14 +08:00
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);
free_irq(moxtet->dev_irq, moxtet);
moxtet_irq_free(moxtet);
moxtet_unregister_debugfs(moxtet);
device_for_each_child(moxtet->dev, NULL, __unregister);
bus: Add support for Moxtet bus 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. Link: https://lore.kernel.org/r/20190812161118.21476-2-marek.behun@nic.cz Signed-off-by: Marek Behún <marek.behun@nic.cz> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-08-13 00:11:14 +08:00
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");