Add a stub clock driver which can be used to bind clock controllers
which aren't required for the platform to boot, but which are needed for
U-Boot drivers to work.
In addition, add a NOP parent driver to allow for binding the parent
nodes of the clock.
Initially this driver supports a Qualcomm platform where the MMC driver
tries to fetch the RPM clock controller, which is not actually required
for the device to work.
Reviewed-by: Neil Armstrong <neil.armstr...@linaro.org>
Acked-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
Signed-off-by: Caleb Connolly <caleb.conno...@linaro.org>
---
drivers/clk/Kconfig | 7 ++++++
drivers/clk/Makefile | 1 +
drivers/clk/clk-stub.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 74 insertions(+)
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index
d9d518d70387120f6261ac4a6ae7038992c5f888..18bd640a68b60a9ba8a87fcd1d5489140653c344
100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -95,8 +95,15 @@ config SPL_CLK_GPIO
help
Enable this option to add GPIO-controlled clock gate driver
in U-Boot SPL.
+config CLK_STUB
+ bool "Stub clock driver"
+ depends on CLK
+ help
+ Enable this to provide a stub clock driver for non-essential clock
+ controllers.
+
config CLK_BCM6345
bool "Clock controller driver for BCM6345"
depends on CLK && ARCH_BMIPS
default y
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index
7f84f22d4b1d100a1116db4c71b067e30283d162..fe0e49f6112e19e86db29c2b039d67ded774eae9
100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -10,8 +10,9 @@ obj-$(CONFIG_$(PHASE_)CLK) += clk_fixed_factor.o
obj-$(CONFIG_$(PHASE_)CLK_CCF) += clk.o clk-divider.o clk-mux.o clk-gate.o
obj-$(CONFIG_$(PHASE_)CLK_CCF) += clk-fixed-factor.o
obj-$(CONFIG_$(PHASE_)CLK_COMPOSITE_CCF) += clk-composite.o
obj-$(CONFIG_$(PHASE_)CLK_GPIO) += clk-gpio.o
+obj-$(CONFIG_$(PHASE_)CLK_STUB) += clk-stub.o
obj-y += adi/
obj-y += analogbits/
obj-y += imx/
diff --git a/drivers/clk/clk-stub.c b/drivers/clk/clk-stub.c
new file mode 100644
index
0000000000000000000000000000000000000000..ea817031fa6c0cc1ea21000273b5651be5d05e65
--- /dev/null
+++ b/drivers/clk/clk-stub.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Stub clk driver for non-essential clocks.
+ *
+ * This driver should be used for clock controllers
+ * which are described as dependencies in DT but aren't
+ * actually necessary for hardware functionality.
+ */
+
+#include <clk-uclass.h>
+#include <dm.h>
+
+/* NOP parent nodes to stub clocks */
+static const struct udevice_id nop_parent_ids[] = {
+ { .compatible = "qcom,rpm-proc" },
+ { .compatible = "qcom,glink-rpm" },
+ { .compatible = "qcom,rpm-sm6115" },
+ { }
+};
+
+U_BOOT_DRIVER(nop_parent) = {
+ .name = "nop_parent",
+ .id = UCLASS_NOP,
+ .of_match = nop_parent_ids,
+ .bind = dm_scan_fdt_dev,
+ .flags = DM_FLAG_DEFAULT_PD_CTRL_OFF,
+};
+
+static ulong stub_clk_set_rate(struct clk *clk, ulong rate)
+{
+ return (clk->rate = rate);
+}
+
+static ulong stub_clk_get_rate(struct clk *clk)
+{
+ return clk->rate;
+}
+
+static int stub_clk_nop(struct clk *clk)
+{
+ return 0;
+}
+
+static struct clk_ops stub_clk_ops = {
+ .set_rate = stub_clk_set_rate,
+ .get_rate = stub_clk_get_rate,
+ .enable = stub_clk_nop,
+ .disable = stub_clk_nop,
+};
+
+static const struct udevice_id stub_clk_ids[] = {
+ { .compatible = "qcom,rpmcc" },
+ { .compatible = "qcom,sm8250-rpmh-clk" },
+ { .compatible = "qcom,sm8550-rpmh-clk" },
+ { .compatible = "qcom,sm8650-rpmh-clk" },
+ { }
+};
+
+U_BOOT_DRIVER(clk_stub) = {
+ .name = "clk_stub",
+ .id = UCLASS_CLK,
+ .ops = &stub_clk_ops,
+ .of_match = stub_clk_ids,
+ .flags = DM_FLAG_DEFAULT_PD_CTRL_OFF,
+};
+
--
2.48.1
