Re: [PATCH v2 1/2] clk: add stub clock driver

On 27/05/2024 19:12, Caleb Connolly wrote:

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.

Signed-off-by: Caleb Connolly caleb.connolly@linaro.org

drivers/clk/Kconfig | 7 ++++++ drivers/clk/Makefile | 1 + drivers/clk/clk-stub.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 71 insertions(+)

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index 9acbc47fe8ed..965bc4959403 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 847b9b291100..b2cea41419b7 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -10,8 +10,9 @@ obj-$(CONFIG_$(SPL_TPL_)CLK) += clk_fixed_factor.o obj-$(CONFIG_$(SPL_TPL_)CLK_CCF) += clk.o clk-divider.o clk-mux.o clk-gate.o obj-$(CONFIG_$(SPL_TPL_)CLK_CCF) += clk-fixed-factor.o obj-$(CONFIG_$(SPL_TPL_)CLK_COMPOSITE_CCF) += clk-composite.o obj-$(CONFIG_$(SPL_TPL_)CLK_GPIO) += clk-gpio.o +obj-$(CONFIG_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 000000000000..3f9c758ef115 --- /dev/null +++ b/drivers/clk/clk-stub.c @@ -0,0 +1,63 @@ +// 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" },

If you resend, please add: - qcom,sm8550-rpmh-clk - qcom,sm8650-rpmh-clk

Thanks, Neil

• { }

+};

+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,

+};