Update documentation to reflect the new phandle support when OF_PLATDATA
is used. Now phandles are implemented as pointers to U_BOOT_DEVICE,
which makes it possible to get a pointer to the actual device.
Signed-off-by: Walter Lozano <walter.loz...@collabora.com>
---
doc/driver-model/of-plat.rst | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/doc/driver-model/of-plat.rst b/doc/driver-model/of-plat.rst
index 376d4409a5..1e3fad137b 100644
--- a/doc/driver-model/of-plat.rst
+++ b/doc/driver-model/of-plat.rst
@@ -69,9 +69,8 @@ strictly necessary. Notable problems include:
- 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 platform data. This pointer can potentially be used to
- access the referenced device (by searching for the pointer value).
- This feature is not yet implemented, however.
+ a pointer to struct driver_info. This pointer can be used to access
+ the referenced device.
How it works
@@ -146,10 +145,10 @@ and the following device declaration:
.clock_freq_min_max = {0x61a80, 0x8f0d180},
.vmmc_supply = 0xb,
.num_slots = 0x1,
- .clocks = {{&dtv_clock_controller_at_ff760000,
456},
- {&dtv_clock_controller_at_ff760000, 68},
- {&dtv_clock_controller_at_ff760000,
114},
- {&dtv_clock_controller_at_ff760000,
118}},
+ .clocks = {{NULL, 456},
+ {NULL, 68},
+ {NULL, 114},
+ {NULL, 118}},
.cap_mmc_highspeed = true,
.disable_wp = true,
.bus_width = 0x4,
@@ -164,6 +163,13 @@ and the following device declaration:
.platdata_size = sizeof(dtv_dwmmc_at_ff0c0000),
};
+ 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
accessed using:
@@ -329,7 +335,9 @@ prevents them being used inadvertently. All usage must be
bracketed with
#if CONFIG_IS_ENABLED(OF_PLATDATA).
The dt-platdata.c file contains the device declarations and is is built in
-spl/dt-platdata.c.
+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.
--
2.20.1
