From 70c79dc88f9678653919c1d1545817876f1c0802 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Wed, 20 Nov 2024 08:36:39 -0700 Subject: [PATCH 1/3] common: Drop check for DM in initf_dm() This is enabled by all boards, so drop the condition. Signed-off-by: Simon Glass Reviewed-by: Tom Rini --- common/board_f.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/common/board_f.c b/common/board_f.c index 54c48d42ee9..d2c24d418fb 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -815,9 +815,11 @@ static int initf_bootstage(void) static int initf_dm(void) { -#if defined(CONFIG_DM) && CONFIG_IS_ENABLED(SYS_MALLOC_F) int ret; + if (!CONFIG_IS_ENABLED(SYS_MALLOC_F)) + return 0; + bootstage_start(BOOTSTAGE_ID_ACCUM_DM_F, "dm_f"); ret = dm_init_and_scan(true); bootstage_accum(BOOTSTAGE_ID_ACCUM_DM_F); @@ -829,7 +831,6 @@ static int initf_dm(void) if (ret) return ret; } -#endif return 0; } From 21dd873572a01d74bfdfceb7a30b056f8ccba187 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Wed, 20 Nov 2024 08:36:40 -0700 Subject: [PATCH 2/3] dm: core: Simplify dm_probe_devices() There is no point in checking the pre_reloc flag, since devices not marked as pre-reloc will not have been bound, so won't exist yet. There doesn't seem to be any point in checking if the device has a valid devicetree node either, so drop that too. Signed-off-by: Simon Glass --- drivers/core/root.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/drivers/core/root.c b/drivers/core/root.c index c7fb58285ca..6388444bfb1 100644 --- a/drivers/core/root.c +++ b/drivers/core/root.c @@ -288,26 +288,20 @@ void *dm_priv_to_rw(void *priv) } #endif -static int dm_probe_devices(struct udevice *dev, bool pre_reloc_only) +static int dm_probe_devices(struct udevice *dev) { - ofnode node = dev_ofnode(dev); struct udevice *child; - int ret; - - if (pre_reloc_only && - (!ofnode_valid(node) || !ofnode_pre_reloc(node)) && - !(dev->driver->flags & DM_FLAG_PRE_RELOC)) - goto probe_children; if (dev_get_flags(dev) & DM_FLAG_PROBE_AFTER_BIND) { + int ret; + ret = device_probe(dev); if (ret) return ret; } -probe_children: list_for_each_entry(child, &dev->child_head, sibling_node) - dm_probe_devices(child, pre_reloc_only); + dm_probe_devices(child); return 0; } @@ -344,7 +338,7 @@ static int dm_scan(bool pre_reloc_only) if (ret) return ret; - return dm_probe_devices(gd->dm_root, pre_reloc_only); + return dm_probe_devices(gd->dm_root); } int dm_init_and_scan(bool pre_reloc_only) From 6995f2c8be901b5f3f4183ccc4a58c209e8bce52 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Wed, 20 Nov 2024 08:36:41 -0700 Subject: [PATCH 3/3] common: Move autoprobe out to board init Rather than doing autoprobe within the driver model code, move it out to the board-init code. This makes it clear that it is a separate step from binding devices. For now this is always done twice, before and after relocation, but we should discuss whether it might be possible to drop the post-relocation probe. For boards with SPL, the autoprobe is still done there as well. Note that with this change, autoprobe happens after the EVT_DM_POST_INIT_R/F events are sent, rather than before. Link: https://lore.kernel.org/u-boot/20240626235717.272219-1-marex@denx.de/ Signed-off-by: Simon Glass --- common/board_f.c | 4 ++++ common/board_r.c | 2 +- common/spl/spl.c | 4 ++++ doc/develop/driver-model/design.rst | 17 +++++++++++++++++ drivers/core/root.c | 22 +++++++++++++++++++++- include/dm/root.h | 15 +++++++++++++++ 6 files changed, 62 insertions(+), 2 deletions(-) diff --git a/common/board_f.c b/common/board_f.c index d2c24d418fb..6c5c3bfab48 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -826,6 +826,10 @@ static int initf_dm(void) if (ret) return ret; + ret = dm_autoprobe(); + if (ret) + return ret; + if (IS_ENABLED(CONFIG_TIMER_EARLY)) { ret = dm_timer_init(); if (ret) diff --git a/common/board_r.c b/common/board_r.c index f63c6aed4d5..179259b00de 100644 --- a/common/board_r.c +++ b/common/board_r.c @@ -250,7 +250,7 @@ static int initr_dm(void) if (ret) return ret; - return 0; + return dm_autoprobe(); } #endif diff --git a/common/spl/spl.c b/common/spl/spl.c index ad31a2f8b6c..02269fff93c 100644 --- a/common/spl/spl.c +++ b/common/spl/spl.c @@ -500,6 +500,10 @@ static int spl_common_init(bool setup_malloc) debug("dm_init_and_scan() returned error %d\n", ret); return ret; } + + ret = dm_autoprobe(); + if (ret) + return ret; } return 0; diff --git a/doc/develop/driver-model/design.rst b/doc/develop/driver-model/design.rst index 8c2c81d7ac9..92f638a0204 100644 --- a/doc/develop/driver-model/design.rst +++ b/doc/develop/driver-model/design.rst @@ -842,6 +842,23 @@ steps (see device_probe()): cause the uclass to do some housekeeping to record the device as activated and 'known' by the uclass. +For some platforms, certain devices must be probed to get the platform into +a working state. To help with this, drivers marked with DM_FLAG_PROBE_AFTER_BIND +will be probed immediately after all devices are bound. For now, this happens in +SPL, before relocation and after relocation. See the call to ``dm_autoprobe()`` +for where this is done. + +The auto-probe feature is tricky because it bypasses the normal ordering of +probing. General, if device A (e.g. video) needs device B (e.g. clock), then +A's probe() method uses ``clk_get_by_index()`` and B is probed before A. But +A is only probed when it is used. Therefore care should be taken when using +auto-probe, limiting it to devices which truly are essential, such as power +domains or critical clocks. + +See here for more discussion of this feature: + +:Link: https://patchwork.ozlabs.org/project/uboot/patch/20240626235717.272219-1-marex@denx.de/ + Running stage ^^^^^^^^^^^^^ diff --git a/drivers/core/root.c b/drivers/core/root.c index 6388444bfb1..15b8c83fee9 100644 --- a/drivers/core/root.c +++ b/drivers/core/root.c @@ -288,6 +288,15 @@ void *dm_priv_to_rw(void *priv) } #endif +/** + * dm_probe_devices() - Check whether to probe a device and all children + * + * Probes the device if DM_FLAG_PROBE_AFTER_BIND is enabled for it. Then scans + * all its children recursively to do the same. + * + * @dev: Device to (maybe) probe + * Return 0 if OK, -ve on error + */ static int dm_probe_devices(struct udevice *dev) { struct udevice *child; @@ -306,6 +315,17 @@ static int dm_probe_devices(struct udevice *dev) return 0; } +int dm_autoprobe(void) +{ + int ret; + + ret = dm_probe_devices(gd->dm_root); + if (ret) + return log_msg_ret("pro", ret); + + return 0; +} + /** * dm_scan() - Scan tables to bind devices * @@ -338,7 +358,7 @@ static int dm_scan(bool pre_reloc_only) if (ret) return ret; - return dm_probe_devices(gd->dm_root); + return 0; } int dm_init_and_scan(bool pre_reloc_only) diff --git a/include/dm/root.h b/include/dm/root.h index 5651b868c8b..286bd9a2ddd 100644 --- a/include/dm/root.h +++ b/include/dm/root.h @@ -136,6 +136,21 @@ int dm_scan_other(bool pre_reloc_only); */ int dm_init_and_scan(bool pre_reloc_only); +/** + * dm_autoprobe() - Probe devices which are marked for probe-after-bind + * + * This probes all devices with a DM_FLAG_PROBE_AFTER_BIND flag. It checks the + * entire tree, so parent nodes need not have the flag set. + * + * It recursively probes parent nodes, so they do not need to have the flag + * set themselves. Since parents are always probed before children, if a child + * has the flag set, then its parent (and any devices up the chain to the root + * device) will be probed too. + * + * Return: 0 if OK, -ve on error + */ +int dm_autoprobe(void); + /** * dm_init() - Initialise Driver Model structures *