[PATCH 01/10] dtoc: add support to scan drivers

[Simon Glass <sjg@chromium.org>]

Hi Walter,

On Fri, 29 May 2020 at 12:15, Walter Lozano <walter.lozano@collabora.com> wrote:
>
> Currently dtoc scans dtbs to convert them to struct platdata and
> to generate U_BOOT_DEVICE entries. These entries need to be filled
> with the driver name, but at this moment the information used is the
> compatible name present in the dtb. This causes that only nodes with
> a compatible name that matches a driver name generate a working
> entry.
>
> In order to improve this behaviour, this patch adds to dtoc the
> capability of scan drivers source code to generate a list of valid driver
> names. This allows to rise a warning in the case that an U_BOOT_DEVICE
> entry will try to use a name not valid.
>
> Additionally, in order to add more flexibility to the solution, adds the
> U_BOOT_DRIVER_ALIAS macro, which generates no code at all, but allows an
> easy way to declare driver name aliases. Thanks to this, dtoc can look
> for the driver name based on its alias when it populates the U_BOOT_DEVICE
> entry.
>
> Signed-off-by: Walter Lozano <walter.lozano@collabora.com>
> ---
>  include/dm/device.h        |  7 ++++
>  tools/dtoc/dtb_platdata.py | 83 ++++++++++++++++++++++++++++++++++++--
>  2 files changed, 86 insertions(+), 4 deletions(-)
>
> diff --git a/include/dm/device.h b/include/dm/device.h
> index 975eec5d0e..2cfe10766f 100644
> --- a/include/dm/device.h
> +++ b/include/dm/device.h
> @@ -282,6 +282,13 @@ struct driver {
>  #define DM_GET_DRIVER(__name)                                          \
>         ll_entry_get(struct driver, __name, driver)
>
> +/**
> + * Declare a macro to state a alias for a driver name. This macro will
> + * produce no code but its information will be parsed by tools like
> + * dtoc
> + */
> +#define U_BOOT_DRIVER_ALIAS(__name, __alias)
> +
>  /**
>   * dev_get_platdata() - Get the platform data for a device
>   *
> diff --git a/tools/dtoc/dtb_platdata.py b/tools/dtoc/dtb_platdata.py
> index ecfe0624d1..23cfda2f88 100644
> --- a/tools/dtoc/dtb_platdata.py
> +++ b/tools/dtoc/dtb_platdata.py
> @@ -13,6 +13,8 @@ static data.
>
>  import collections
>  import copy
> +import os
> +import re
>  import sys
>
>  from dtoc import fdt
> @@ -140,6 +142,9 @@ class DtbPlatdata(object):
>          _include_disabled: true to include nodes marked status = "disabled"
>          _outfile: The current output file (sys.stdout or a real file)
>          _lines: Stashed list of output lines for outputting in the future
> +        _aliases: Dict that hold aliases for compatible strings
key: The driver name, i.e. the part between brackets in U_BOOT_DRIVER(xx)  ??
value: ...
> +        _drivers: List of valid driver names found in drivers/
> +        _driver_aliases: Dict that holds aliases for driver names
key:
vaue:

>      """
>      def __init__(self, dtb_fname, include_disabled):
>          self._fdt = None
> @@ -149,6 +154,35 @@ class DtbPlatdata(object):
>          self._outfile = None
>          self._lines = []
>          self._aliases = {}
> +        self._drivers = []
> +        self._driver_aliases = {}
> +
> +    def get_normalized_compat_name(self, node):
> +        """Get a node's normalized compat name
> +
> +        Returns a valid driver name by retrieving node's first compatible
> +        string as a C identifier and perfomrming a check against _drivers

performing

> +        and a lookup in driver_aliases rising a warning in case of failure.

s/ rising/, printing/

> +
> +        Args:
> +            node: Node object to check
> +        Return:
> +            Tuple:
> +                Driver name associated with the first compatible string
> +                List of C identifiers for all the other compatible strings
> +                    (possibly empty)

Can you update this comment to explain what is returned when it is not found?

> +        """
> +        compat_c, aliases_c = get_compat_name(node)
> +        if compat_c not in self._drivers:
> +            compat_c_old = compat_c
> +            compat_c = self._driver_aliases.get(compat_c)
> +            if not compat_c:
> +                print('WARNING: the driver %s was not found in the driver list' % (compat_c_old))

This creates lots of warnings at present. Either we need a patch to
clean up the differences in the source code, or we need to disable the
warning.

Also the warning is not really actionable. It needs to add mention of
U_BOOT_DEVICE and ...ALIAS.

In future we can scan the compatible strings and tell the user what
changes to make, I suppose.

> +                compat_c = compat_c_old
> +            else: # pragma: no cover

Need to fix the coverage here

> +                aliases_c = [compat_c_old] + aliases_c
> +
> +        return compat_c, aliases_c
>
>      def setup_output(self, fname):
>          """Set up the output destination
> @@ -243,6 +277,46 @@ class DtbPlatdata(object):
>              return PhandleInfo(max_args, args)
>          return None
>
> +    def scan_driver(self, fn):
> +        """Scan a driver file to build a list of driver names and aliases
> +
> +        This procedure will populate self._drivers and self._driver_aliases
> +
> +        Args
> +            fn: Driver filename to scan
> +        """
> +        with open(fn) as fd:
> +

drop blank line

> +            buff = fd.read()
> +
> +            # The following re will search for driver names declared as
> +            # U_BOOT_DRIVER(driver_name)
> +            drivers = re.findall('U_BOOT_DRIVER\((.*)\)', buff)
> +
> +            for driver in drivers:
> +                self._drivers.append(driver)
> +
> +            # The following re will search for driver aliases declared as
> +            # U_BOOT_DRIVER_ALIAS(alias, driver_name)
> +            driver_aliases = re.findall('U_BOOT_DRIVER_ALIAS\(\s*(\w+)\s*,\s*(\w+)\s*\)', buff)
> +
> +            for alias in driver_aliases: # pragma: no cover
> +                if len(alias) != 2:
> +                    continue
> +                self._driver_aliases[alias[1]] = alias[0]
> +
> +    def scan_drivers(self):
> +        """Scan the driver folders to build a list of driver names and aliases
> +
> +        This procedure will populate self._drivers and self._driver_aliases
> +
> +        """
> +        for (dirpath, dirnames, filenames) in os.walk('./'):

This doesn't work for out-of-tree cases (make O=xxx). You may need to
pass $(srctree) to dtc as an argument.

> +            for fn in filenames:
> +                if not fn.endswith('.c'):
> +                    continue
> +                self.scan_driver(dirpath + '/' + fn)
> +
>      def scan_dtb(self):
>          """Scan the device tree to obtain a tree of nodes and properties
>
> @@ -353,7 +427,7 @@ class DtbPlatdata(object):
>          """
>          structs = {}
>          for node in self._valid_nodes:
> -            node_name, _ = get_compat_name(node)
> +            node_name, _ = self.get_normalized_compat_name(node)
>              fields = {}
>
>              # Get a list of all the valid properties in this node.
> @@ -377,14 +451,14 @@ class DtbPlatdata(object):
>
>          upto = 0
>          for node in self._valid_nodes:
> -            node_name, _ = get_compat_name(node)
> +            node_name, _ = self.get_normalized_compat_name(node)
>              struct = structs[node_name]
>              for name, prop in node.props.items():
>                  if name not in PROP_IGNORE_LIST and name[0] != '#':
>                      prop.Widen(struct[name])
>              upto += 1
>
> -            struct_name, aliases = get_compat_name(node)
> +            struct_name, aliases = self.get_normalized_compat_name(node)
>              for alias in aliases:
>                  self._aliases[alias] = struct_name
>
> @@ -461,7 +535,7 @@ class DtbPlatdata(object):
>          Args:
>              node: node to output
>          """
> -        struct_name, _ = get_compat_name(node)
> +        struct_name, _ = self.get_normalized_compat_name(node)
>          var_name = conv_name_to_c(node.name)
>          self.buf('static const struct %s%s %s%s = {\n' %
>                   (STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name))
> @@ -562,6 +636,7 @@ def run_steps(args, dtb_file, include_disabled, output):
>          raise ValueError('Please specify a command: struct, platdata')
>
>      plat = DtbPlatdata(dtb_file, include_disabled)
> +    plat.scan_drivers()
>      plat.scan_dtb()
>      plat.scan_tree()
>      plat.scan_reg_sizes()
> --
> 2.20.1
>

Regards,
Simon