@@ -31,6 +31,7 @@ struct ingenic_soc_info {
unsigned int num_channels;
bool has_ost;
bool has_tcu_clk;
+ bool allow_missing_tcu_clk;
};
struct ingenic_tcu_clk_info {
@@ -320,7 +321,8 @@ static const struct ingenic_soc_info jz4770_soc_info = {
static const struct ingenic_soc_info x1000_soc_info = {
.num_channels = 8,
.has_ost = false, /* X1000 has OST, but it not belong TCU */
- .has_tcu_clk = false,
+ .has_tcu_clk = true,
+ .allow_missing_tcu_clk = true,
};
static const struct of_device_id __maybe_unused ingenic_tcu_of_match[] __initconst = {
@@ -355,14 +357,29 @@ static int __init ingenic_tcu_probe(struct device_node *np)
tcu->clk = of_clk_get_by_name(np, "tcu");
if (IS_ERR(tcu->clk)) {
ret = PTR_ERR(tcu->clk);
- pr_crit("Cannot get TCU clock\n");
- goto err_free_tcu;
- }
- ret = clk_prepare_enable(tcu->clk);
- if (ret) {
- pr_crit("Unable to enable TCU clock\n");
- goto err_put_clk;
+ /*
+ * Old versions of this driver incorrectly specified
+ * some SoCs as not having a TCU clock, so old device
+ * trees didn't define one. We try to allow the kernel
+ * to boot with an old device tree by just continuing
+ * on without the clock and hoping it won't get turned
+ * off (eg. with "clk_ignore_unused" kernel argument).
+ */
+ if (ret == -EINVAL &&
+ tcu->soc_info->allow_missing_tcu_clk) {
+ pr_warn("TCU clock missing from device tree, please update your device tree\n");
+ tcu->clk = NULL;
+ } else {
+ pr_crit("Cannot get TCU clock\n");
+ goto err_free_tcu;
+ }
+ } else {
+ ret = clk_prepare_enable(tcu->clk);
+ if (ret) {
+ pr_crit("Unable to enable TCU clock\n");
+ goto err_put_clk;
+ }
}
}
@@ -432,10 +449,10 @@ static int __init ingenic_tcu_probe(struct device_node *np)
clk_hw_unregister(tcu->clocks->hws[i]);
kfree(tcu->clocks);
err_clk_disable:
- if (tcu->soc_info->has_tcu_clk)
+ if (tcu->clk)
clk_disable_unprepare(tcu->clk);
err_put_clk:
- if (tcu->soc_info->has_tcu_clk)
+ if (tcu->clk)
clk_put(tcu->clk);
err_free_tcu:
kfree(tcu);
The X1000 and X1830 have a TCU clock gate, so pass it to the driver. Without this the TCU can be gated automatically, which prevents timers from running. Add a workaround to allow the driver to probe even if the TCU clock is missing on the affected SoCs; in this case the TCU clock is ignored, as it was before. With workarounds like "clk_ignore_unused" on the kernel command line, this allows users who upgrade the kernel but use the old device tree to boot successfully. They will now get a warning encouraging them to update the device tree. Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com> --- drivers/clk/ingenic/tcu.c | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-)