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authorTom Rini <trini@konsulko.com>2020-10-30 15:24:30 -0400
committerTom Rini <trini@konsulko.com>2020-10-30 15:24:30 -0400
commit63d4607e03e5f1f7ab9a18bc640e31f7d28874b4 (patch)
treebdea1f28ad176fcd44f209bf943d25c8bddbe8d2 /doc
parent096912b5fe9bb2fd90599d86a714001df6924198 (diff)
parent2424057b2ad0eacdd2d81e35e7bea5df97802b8f (diff)
Merge tag 'dm-pull-30oct20' of https://gitlab.denx.de/u-boot/custodians/u-boot-dm
of-platdata and dtoc improvements sandbox SPL tests binman support for compressed sections
Diffstat (limited to 'doc')
-rw-r--r--doc/driver-model/of-plat.rst42
1 files changed, 19 insertions, 23 deletions
diff --git a/doc/driver-model/of-plat.rst b/doc/driver-model/of-plat.rst
index 1e3fad137b..58481665ce 100644
--- a/doc/driver-model/of-plat.rst
+++ b/doc/driver-model/of-plat.rst
@@ -66,12 +66,6 @@ strictly necessary. Notable problems include:
normally also supports device tree it must use #ifdef to separate
out this code, since the structures are only available in SPL.
- - Correct relations between nodes are not implemented. This means that
- parent/child relations (like bus device iteration) do not work yet.
- Some phandles (those that are recognised as such) are converted into
- a pointer to struct driver_info. This pointer can be used to access
- the referenced device.
-
How it works
------------
@@ -134,10 +128,14 @@ the following C struct declaration:
fdt32_t vmmc_supply;
};
-and the following device declaration:
+and the following device declarations:
.. code-block:: c
+ /* Node /clock-controller@ff760000 index 0 */
+ ...
+
+ /* Node /dwmmc@ff0c0000 index 2 */
static struct dtd_rockchip_rk3288_dw_mshc dtv_dwmmc_at_ff0c0000 = {
.fifo_depth = 0x100,
.cap_sd_highspeed = true,
@@ -145,10 +143,10 @@ and the following device declaration:
.clock_freq_min_max = {0x61a80, 0x8f0d180},
.vmmc_supply = 0xb,
.num_slots = 0x1,
- .clocks = {{NULL, 456},
- {NULL, 68},
- {NULL, 114},
- {NULL, 118}},
+ .clocks = {{0, 456},
+ {0, 68},
+ {0, 114},
+ {0, 118}},
.cap_mmc_highspeed = true,
.disable_wp = true,
.bus_width = 0x4,
@@ -161,13 +159,10 @@ and the following device declaration:
.name = "rockchip_rk3288_dw_mshc",
.platdata = &dtv_dwmmc_at_ff0c0000,
.platdata_size = sizeof(dtv_dwmmc_at_ff0c0000),
+ .parent_idx = -1,
};
void dm_populate_phandle_data(void) {
- dtv_dwmmc_at_ff0c0000.clocks[0].node = DM_GET_DEVICE(clock_controller_at_ff760000);
- dtv_dwmmc_at_ff0c0000.clocks[1].node = DM_GET_DEVICE(clock_controller_at_ff760000);
- dtv_dwmmc_at_ff0c0000.clocks[2].node = DM_GET_DEVICE(clock_controller_at_ff760000);
- dtv_dwmmc_at_ff0c0000.clocks[3].node = DM_GET_DEVICE(clock_controller_at_ff760000);
}
The device is then instantiated at run-time and the platform data can be
@@ -193,6 +188,13 @@ In order to make this a bit more flexible U_BOOT_DRIVER_ALIAS macro can be
used to declare an alias for a driver name, typically a 'compatible' string.
This macro produces no code, but it is by dtoc tool.
+The parent_idx is the index of the parent driver_info structure within its
+linker list (instantiated by the U_BOOT_DEVICE() macro). This is used to support
+dev_get_parent(). The dm_populate_phandle_data() is included to allow for
+fix-ups required by dtoc. It is not currently used. The values in 'clocks' are
+the index of the driver_info for the target device followed by any phandle
+arguments. This is used to support device_get_by_driver_info_idx().
+
During the build process dtoc parses both U_BOOT_DRIVER and U_BOOT_DRIVER_ALIAS
to build a list of valid driver names and driver aliases. If the 'compatible'
string used for a device does not not match a valid driver name, it will be
@@ -339,12 +341,7 @@ spl/dt-platdata.c. It additionally contains the definition of
dm_populate_phandle_data() which is responsible of filling the phandle
information by adding references to U_BOOT_DEVICE by using DM_GET_DEVICE
-The beginnings of a libfdt Python module are provided. So far this only
-implements a subset of the features.
-
-The 'swig' tool is needed to build the libfdt Python module. If this is not
-found then the Python model is not used and a fallback is used instead, which
-makes use of fdtget.
+The pylibfdt Python module is used to access the devicetree.
Credits
@@ -357,11 +354,10 @@ Future work
-----------
- Consider programmatically reading binding files instead of device tree
contents
-- Complete the phandle feature
-- Move to using a full Python libfdt module
.. Simon Glass <sjg@chromium.org>
.. Google, Inc
.. 6/6/16
.. Updated Independence Day 2016
+.. Updated 1st October 2020