This fixes the case where assigned-clocks is used to define a clock defaults inside this same clock's node. This is used sometimes to setup a default parents and/or rate for a clock.
example: muxed_clock: muxed_clock { clocks = <&clk_provider 0>, <&clk_provider 1>; #clock-cells = <0>; assigned-clocks = <&muxed_clock>; assigned-clock-parents = <&clk_provider 1>; };
It doesn't work in u-boot because the assigned-clocks are setup *before* the clock is probed. (clk_set_parent() will likely crash or fail if called before the device probe function) Making it work by handling "assigned-clocks" in 2 steps: first before the clk device is probed, and then after the clk device is probed.
Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com ---
drivers/clk/clk-uclass.c | 48 +++++++++++++++++++++++++++++++++++----- drivers/core/device.c | 2 +- include/clk.h | 7 ++++-- 3 files changed, 48 insertions(+), 9 deletions(-)
diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c index e7ec6347de..75d618a47b 100644 --- a/drivers/clk/clk-uclass.c +++ b/drivers/clk/clk-uclass.c @@ -178,7 +178,7 @@ bulk_get_err: return ret; }
-static int clk_set_default_parents(struct udevice *dev) +static int clk_set_default_parents(struct udevice *dev, int stage) { struct clk clk, parent_clk; int index; @@ -214,8 +214,18 @@ static int clk_set_default_parents(struct udevice *dev) return ret; }
- ret = clk_set_parent(&clk, &parent_clk); + /* This is clk provider device trying to reparent itself + * It cannot be done right now but need to wait after the + * device is probed + */ + if (stage == 0 && clk.dev == dev) + continue; + + if (stage > 0 && clk.dev != dev) + /* do not setup twice the parent clocks */ + continue;
+ ret = clk_set_parent(&clk, &parent_clk); /* * Not all drivers may support clock-reparenting (as of now). * Ignore errors due to this. @@ -233,7 +243,7 @@ static int clk_set_default_parents(struct udevice *dev) return 0; }
-static int clk_set_default_rates(struct udevice *dev) +static int clk_set_default_rates(struct udevice *dev, int stage) { struct clk clk; int index; @@ -268,7 +278,19 @@ static int clk_set_default_rates(struct udevice *dev) continue; }
+ /* This is clk provider device trying to program itself + * It cannot be done right now but need to wait after the + * device is probed + */ + if (stage == 0 && clk.dev == dev) + continue; + + if (stage > 0 && clk.dev != dev) + /* do not setup twice the parent clocks */ + continue; + ret = clk_set_rate(&clk, rates[index]); + if (ret < 0) { debug("%s: failed to set rate on clock index %d (%ld) for %s\n", __func__, index, clk.id, dev_read_name(dev)); @@ -281,7 +303,7 @@ fail: return ret; }
-int clk_set_defaults(struct udevice *dev) +int clk_set_defaults(struct udevice *dev, int stage) { int ret;
@@ -294,11 +316,11 @@ int clk_set_defaults(struct udevice *dev)
debug("%s(%s)\n", __func__, dev_read_name(dev));
- ret = clk_set_default_parents(dev); + ret = clk_set_default_parents(dev, stage); if (ret) return ret;
- ret = clk_set_default_rates(dev); + ret = clk_set_default_rates(dev, stage); if (ret < 0) return ret;
@@ -673,7 +695,21 @@ void devm_clk_put(struct udevice *dev, struct clk *clk) WARN_ON(rc); }
+int clk_uclass_post_probe(struct udevice *dev) +{ + /* + * when a clock provider is probed. Call clk_set_defaults() + * also after the device is probed. This takes care of cases + * where the DT is used to setup default parents and rates + * using assigned-clocks + */ + clk_set_defaults(dev, 1); + + return 0; +} + UCLASS_DRIVER(clk) = { .id = UCLASS_CLK, .name = "clk", + .post_probe = clk_uclass_post_probe, }; diff --git a/drivers/core/device.c b/drivers/core/device.c index 05dadf98f9..cbcbb1b15d 100644 --- a/drivers/core/device.c +++ b/drivers/core/device.c @@ -416,7 +416,7 @@ int device_probe(struct udevice *dev) * Process 'assigned-{clocks/clock-parents/clock-rates}' * properties */ - ret = clk_set_defaults(dev); + ret = clk_set_defaults(dev, 0); if (ret) goto fail; } diff --git a/include/clk.h b/include/clk.h index 6c5bf8ad67..f6739f7149 100644 --- a/include/clk.h +++ b/include/clk.h @@ -244,10 +244,13 @@ static inline int clk_release_all(struct clk *clk, int count) * * @dev: A device to process (the ofnode associated with this device * will be processed). + * @stage: A integer. 0 indicates that this is called before the device + * is probed. 1 indicates that this is called just after the + * device has been probed */ -int clk_set_defaults(struct udevice *dev); +int clk_set_defaults(struct udevice *dev, int stage); #else -static inline int clk_set_defaults(struct udevice *dev) +static inline int clk_set_defaults(struct udevice *dev, int stage) { return 0; }