devtree.c File Reference

Devicetree bus. More...

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <ipxe/device.h>
#include <ipxe/fdt.h>
#include <ipxe/iomap.h>
#include <ipxe/devtree.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
void *	dt_ioremap (struct dt_device *dt, unsigned int offset, unsigned int index, size_t len)
	Map devicetree range. More...
static struct dt_driver *	dt_find_driver (struct dt_device *dt, unsigned int offset)
	Find devicetree driver. More...
static int	dt_probe (struct dt_device *dt, unsigned int offset)
	Probe devicetree device. More...
static void	dt_remove (struct dt_device *dt)
	Remove devicetree device. More...
int	dt_probe_node (struct device *parent, unsigned int offset)
	Probe devicetree node. More...
void	dt_remove_node (struct device *parent)
	Remove devicetree node. More...
int	dt_probe_children (struct dt_device *parent, unsigned int offset)
	Probe devicetree children. More...
void	dt_remove_children (struct dt_device *parent)
	Remove devicetree children. More...
static int	dt_probe_all (struct root_device *rootdev)
	Probe devicetree bus. More...
static void	dt_remove_all (struct root_device *rootdev)
	Remove devicetree bus. More...

Variables
static struct dt_driver dt_node_driver	__dt_driver
	Generic node driver. More...
static struct root_driver	dt_root_driver
	Devicetree bus root device driver. More...
struct root_device dt_root_device	__root_device
	Devicetree bus root device. More...

Detailed Description

Devicetree bus.

Definition in file devtree.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

dt_ioremap()

void* dt_ioremap	(	struct dt_device *	dt,
		unsigned int	offset,
		unsigned int	index,
		size_t	len
	)

Map devicetree range.

Parameters

dt	Devicetree device
offset	Starting node offset
index	Region index
len	Length to map, or 0 to map whole region

Return values

io_addr

I/O address, or NULL on error

Definition at line 52 of file devtree.c.

                                                     {
        struct fdt_reg_cells regs;
        uint64_t address;
        uint64_t size;
        void *io_addr;
        int rc;

        /* Get parent region cell size specification */
        if ( ( rc = fdt_parent_reg_cells ( &sysfdt, offset, &regs ) ) != 0 ) {
                DBGC ( dt, "DT %s could not get region cell sizes: %s\n",
                       dt->name, strerror ( rc ) );
                return NULL;
        }

        /* Read address */
        if ( ( rc = fdt_reg_address ( &sysfdt, offset, &regs, index,
                                      &address ) ) != 0 ) {
                DBGC ( dt, "DT %s could not read region %d address: %s\n",
                       dt->name, index, strerror ( rc ) );
                return NULL;
        }

        /* Read size (or assume sufficient, if tree specifies no sizes) */
        size = len;
        if ( regs.size_cells &&
             ( ( rc = fdt_reg_size ( &sysfdt, offset, &regs, index,
                                     &size ) ) != 0 ) ) {
                DBGC ( dt, "DT %s could not read region %d size: %s\n",
                       dt->name, index, strerror ( rc ) );
                return NULL;
        }

        /* Use region size as length if not specified */
        if ( ! len )
                len = size;
        DBGC ( dt, "DT %s region %d at %#08llx+%#04llx\n",
               dt->name, index, ( ( unsigned long long ) address ),
               ( ( unsigned long long ) size ) );

        /* Verify size */
        if ( len > size ) {
                DBGC ( dt, "DT %s region %d is too small (%#llx/%#zx bytes)\n",
                       dt->name, index, ( ( unsigned long long ) size ), len );
                return NULL;
        }

        /* Map region */
        io_addr = ioremap ( address, len );
        if ( ! io_addr ) {
                DBGC ( dt, "DT %s could not map region %d\n",
                       dt->name, index );
                return NULL;
        }

        return io_addr;
}

References address, DBGC, fdt_parent_reg_cells(), fdt_reg_address(), fdt_reg_size(), index, ioremap(), len, dt_device::name, NULL, offset, rc, regs, size, strerror(), and sysfdt.

Referenced by cgem_probe(), dwgpio_group_probe(), dwmac_probe(), dwuart_probe(), and dwusb_probe().

dt_find_driver()

static struct dt_driver* dt_find_driver ( struct dt_device *  dt, unsigned int  offset  )

static

Find devicetree driver.

Parameters

dt	Devicetree device
offset	Starting node offset

Return values

driver

Driver

Definition at line 117 of file devtree.c.

                                                                 {
        struct dt_driver *driver;
        const char *ids;
        const char *id;
        unsigned int count;
        unsigned int i;

        /* Read compatible programming model identifiers */
        ids = fdt_strings ( &sysfdt, offset, "compatible", &count );

        /* Look for a compatible driver */
        for ( id = ids ; count-- ; id += ( strlen ( id ) + 1 ) ) {
                DBGC2 ( &sysfdt, "DT %s is compatible with %s\n",
                        dt->name, id );
                for_each_table_entry ( driver, DT_DRIVERS ) {
                        for ( i = 0 ; i < driver->id_count ; i++ ) {
                                if ( strcmp ( id, driver->ids[i] ) == 0 ) {
                                        DBGC ( dt, "DT %s has %s driver %s\n",
                                               dt->name, id, driver->name );
                                        return driver;
                                }
                        }
                }
        }

        /* Use generic node driver if no other driver matches */
        return &dt_node_driver;
}

References count, DBGC, DBGC2, DT_DRIVERS, fdt_strings(), for_each_table_entry, id, dt_driver::id_count, dt_driver::ids, ids, dt_device::name, dt_driver::name, offset, strcmp(), strlen(), and sysfdt.

Referenced by dt_probe().

dt_probe()

static int dt_probe ( struct dt_device *  dt, unsigned int  offset  )

static

Probe devicetree device.

Parameters

dt	Devicetree device
offset	Starting node offset

Return values

rc	Return status code

Definition at line 154 of file devtree.c.

                                                                  {
        struct dt_driver *driver;
        int rc;

        /* Identify driver */
        driver = dt_find_driver ( dt, offset );
        dt->driver = driver;
        dt->dev.driver_name = driver->name;

        /* Probe device */
        if ( ( rc = driver->probe ( dt, offset ) ) != 0 ) {
                if ( driver != &dt_node_driver ) {
                        DBGC ( dt, "DT %s could not probe: %s\n",
                               dt->name, strerror ( rc ) );
                }
                return rc;
        }

        return 0;
}

References DBGC, dt_device::dev, dt_device::driver, device::driver_name, dt_find_driver(), dt_device::name, dt_driver::name, offset, dt_driver::probe, rc, and strerror().

Referenced by dt_probe_node().

dt_remove()

static void dt_remove ( struct dt_device *  dt )

static

Remove devicetree device.

Parameters

dt	Devicetree device

Definition at line 180 of file devtree.c.

                                               {
        struct dt_driver *driver = dt->driver;

        /* Remove device */
        driver->remove ( dt );
        if ( driver != &dt_node_driver )
                DBGC ( dt, "DT %s removed\n", dt->name );
}

References DBGC, dt_device::driver, dt_device::name, and dt_driver::remove.

Referenced by dt_probe_node(), and dt_remove_node().

dt_probe_node()

int dt_probe_node	(	struct device *	parent,
		unsigned int	offset
	)

Probe devicetree node.

Parameters

parent	Parent generic device
offset	Starting node offset

Return values

rc	Return status code

Definition at line 196 of file devtree.c.

                                                                 {
        struct fdt_descriptor desc;
        struct dt_device *dt;
        const char *name;
        int rc;

        /* Describe token */
        if ( ( rc = fdt_describe ( &sysfdt, offset, &desc ) ) != 0 )
                goto err_describe;

        /* Allocate and initialise device */
        dt = zalloc ( sizeof ( *dt ) );
        if ( ! dt ) {
                rc = -ENOMEM;
                goto err_alloc;
        }
        name = ( offset ? desc.name : "root node" );
        dt->name = dt->dev.name;
        snprintf ( dt->dev.name, sizeof ( dt->dev.name ), "%s", name );
        dt->dev.desc.bus_type = BUS_TYPE_DT;
        dt->dev.desc.location = fdt_phandle ( &sysfdt, offset );
        dt->dev.parent = parent;
        INIT_LIST_HEAD ( &dt->dev.children );
        list_add_tail ( &dt->dev.siblings, &parent->children );

        /* Probe device */
        if ( ( rc = dt_probe ( dt, offset ) ) != 0 )
                goto err_probe;

        return 0;

        dt_remove ( dt );
 err_probe:
        list_del ( &dt->dev.siblings );
        free ( dt );
 err_alloc:
 err_describe:
        return rc;
}

References device_description::bus_type, BUS_TYPE_DT, device::children, desc, device::desc, dt_device::dev, dt_probe(), dt_remove(), ENOMEM, fdt_describe(), fdt_phandle(), free, INIT_LIST_HEAD, list_add_tail, list_del, device_description::location, dt_device::name, device::name, name, offset, device::parent, rc, device::siblings, snprintf(), sysfdt, and zalloc().

Referenced by dt_probe_all(), dt_probe_children(), and fdtcon_default().

dt_remove_node()

void dt_remove_node

(

struct device *

parent

)

Remove devicetree node.

Parameters

parent

Parent generic device

Definition at line 241 of file devtree.c.

                                              {
        struct dt_device *dt;

        /* Identify most recently added child */
        dt = list_last_entry ( &parent->children, struct dt_device,
                               dev.siblings );
        assert ( dt != NULL );

        /* Remove driver */
        dt_remove ( dt );

        /* Delete and free device */
        list_del ( &dt->dev.siblings );
        free ( dt );
}

References assert(), device::children, dt_device::dev, dt_remove(), free, list_del, list_last_entry, NULL, and device::siblings.

Referenced by dt_remove_all(), and dt_remove_children().

dt_probe_children()

int dt_probe_children	(	struct dt_device *	parent,
		unsigned int	offset
	)

Probe devicetree children.

Parameters

parent	Parent device
offset	Starting node offset

Return values

rc	Return status code

Definition at line 264 of file devtree.c.

                                                                        {
        struct fdt_descriptor desc;
        int depth;
        int rc;

        /* Probe any immediate child nodes */
        for ( depth = -1 ; ; depth += desc.depth, offset = desc.next ) {

                /* Describe token */
                if ( ( rc = fdt_describe ( &sysfdt, offset, &desc ) ) != 0 ) {
                        DBGC ( &sysfdt, "DT %s has malformed node: %s\n",
                               parent->name, strerror ( rc ) );
                        goto err_describe;
                }

                /* Terminate when we exit this node */
                if ( ( depth == 0 ) && ( desc.depth < 0 ) )
                        break;

                /* Probe child node, if applicable */
                if ( ( depth == 0 ) && desc.name && ( ! desc.data ) ) {
                        DBGC2 ( &sysfdt, "DT %s is child of %s\n",
                                desc.name, parent->name );
                        dt_probe_node ( &parent->dev, desc.offset );
                }
        }

        /* Fail if we have no children (so that this device will be freed) */
        if ( list_empty ( &parent->dev.children ) ) {
                rc = -ENODEV;
                goto err_no_children;
        }

        return 0;

 err_no_children:
 err_describe:
        dt_remove_children ( parent );
        return rc;
}

References device::children, DBGC, DBGC2, fdt_descriptor::depth, desc, dt_device::dev, dt_probe_node(), dt_remove_children(), ENODEV, fdt_describe(), list_empty, dt_device::name, offset, rc, strerror(), and sysfdt.

Referenced by dwgpio_group_probe().

dt_remove_children()

void dt_remove_children

(

struct dt_device *

parent

)

Remove devicetree children.

Parameters

parent

Parent device

Definition at line 310 of file devtree.c.

                                                     {

        /* Remove all child nodes */
        while ( ! list_empty ( &parent->dev.children ) )
                dt_remove_node ( &parent->dev );
}

References device::children, dt_device::dev, dt_remove_node(), and list_empty.

Referenced by dt_probe_children(), dwgpio_group_probe(), and dwgpio_group_remove().

dt_probe_all()

static int dt_probe_all ( struct root_device *  rootdev )

static

Probe devicetree bus.

Parameters

rootdev

Devicetree root device

Return values

rc	Return status code

Definition at line 330 of file devtree.c.

                                                        {

        /* Probe root node */
        return dt_probe_node ( &rootdev->dev, 0 );
}

References root_device::dev, and dt_probe_node().

dt_remove_all()

static void dt_remove_all ( struct root_device *  rootdev )

static

Remove devicetree bus.

Parameters

rootdev

Devicetree root device

Definition at line 341 of file devtree.c.

                                                          {

        /* Remove root node */
        dt_remove_node ( &rootdev->dev );
}

References root_device::dev, and dt_remove_node().

Variable Documentation

__dt_driver

struct dt_driver dt_node_driver __dt_driver

static

Initial value:

= {
        .name = "node",
        .probe = dt_probe_children,
        .remove = dt_remove_children,
}

Generic node driver.

Definition at line 41 of file devtree.c.

dt_root_driver

struct root_driver dt_root_driver

static

Initial value:

= {
        .probe = dt_probe_all,
        .remove = dt_remove_all,
}

Devicetree bus root device driver.

Definition at line 348 of file devtree.c.

__root_device

struct root_device dt_root_device __root_device

Initial value:

= {
        .dev = { .name = "DT" },
        .driver = &dt_root_driver,
}

Devicetree bus root device.

Definition at line 354 of file devtree.c.