Before XO refclk is distributed to PCIe/USB/eDP PHYs, it passes through a QREF block. QREF is powered by dedicated LDO rails, and the clkref_en register controls whether refclk is gated through to the PHY side.
These clkref controls are different from typical GCC branch clocks: - only a single enable bit is present, without branch-style config bits - regulators must be voted before enable and unvoted after disable Model this as a dedicated clk_ref clock type with custom clk_ops instead of reusing struct clk_branch semantics. Also provide a common registration/probe API so the same clkref model can be reused regardless of where clkref_en registers are placed, e.g. TCSR on glymur and TLMM on SM8750. Reviewed-by: Konrad Dybcio <[email protected]> Signed-off-by: Qiang Yu <[email protected]> --- drivers/clk/qcom/Makefile | 1 + drivers/clk/qcom/clk-ref.c | 205 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/clk/qcom.h | 67 +++++++++++++++ 3 files changed, 273 insertions(+) diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile index 81237e2c8db3..143fb7253d65 100644 --- a/drivers/clk/qcom/Makefile +++ b/drivers/clk/qcom/Makefile @@ -8,6 +8,7 @@ clk-qcom-y += clk-pll.o clk-qcom-y += clk-rcg.o clk-qcom-y += clk-rcg2.o clk-qcom-y += clk-branch.o +clk-qcom-y += clk-ref.o clk-qcom-y += clk-regmap-divider.o clk-qcom-y += clk-regmap-mux.o clk-qcom-y += clk-regmap-mux-div.o diff --git a/drivers/clk/qcom/clk-ref.c b/drivers/clk/qcom/clk-ref.c new file mode 100644 index 000000000000..3efdf6749770 --- /dev/null +++ b/drivers/clk/qcom/clk-ref.c @@ -0,0 +1,205 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2026, Qualcomm Technologies, Inc. and/or its subsidiaries. + */ + +#include <linux/clk-provider.h> +#include <linux/clk/qcom.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/slab.h> + +#define QCOM_CLK_REF_EN_MASK BIT(0) + +struct qcom_clk_ref_provider { + size_t num_refs; + struct qcom_clk_ref refs[] __counted_by(num_refs); +}; + +static inline struct qcom_clk_ref *to_qcom_clk_ref(struct clk_hw *hw) +{ + return container_of(hw, struct qcom_clk_ref, hw); +} + +static const struct clk_parent_data qcom_clk_ref_parent_data = { + .index = 0, +}; + +static int qcom_clk_ref_prepare(struct clk_hw *hw) +{ + struct qcom_clk_ref *rclk = to_qcom_clk_ref(hw); + int ret; + + if (!rclk->desc.num_regulators) + return 0; + + ret = regulator_bulk_enable(rclk->desc.num_regulators, rclk->regulators); + if (ret) + pr_err("Failed to enable regulators for %s: %d\n", + clk_hw_get_name(hw), ret); + + return ret; +} + +static void qcom_clk_ref_unprepare(struct clk_hw *hw) +{ + struct qcom_clk_ref *rclk = to_qcom_clk_ref(hw); + + if (rclk->desc.num_regulators) + regulator_bulk_disable(rclk->desc.num_regulators, rclk->regulators); +} + +static int qcom_clk_ref_enable(struct clk_hw *hw) +{ + struct qcom_clk_ref *rclk = to_qcom_clk_ref(hw); + int ret; + + ret = regmap_set_bits(rclk->regmap, rclk->desc.offset, QCOM_CLK_REF_EN_MASK); + if (ret) + return ret; + + udelay(10); + + return 0; +} + +static void qcom_clk_ref_disable(struct clk_hw *hw) +{ + struct qcom_clk_ref *rclk = to_qcom_clk_ref(hw); + + regmap_clear_bits(rclk->regmap, rclk->desc.offset, QCOM_CLK_REF_EN_MASK); + udelay(10); +} + +static int qcom_clk_ref_is_enabled(struct clk_hw *hw) +{ + struct qcom_clk_ref *rclk = to_qcom_clk_ref(hw); + u32 val; + int ret; + + ret = regmap_read(rclk->regmap, rclk->desc.offset, &val); + if (ret) + return 0; + + return !!(val & QCOM_CLK_REF_EN_MASK); +} + +static const struct clk_ops qcom_clk_ref_ops = { + .prepare = qcom_clk_ref_prepare, + .unprepare = qcom_clk_ref_unprepare, + .enable = qcom_clk_ref_enable, + .disable = qcom_clk_ref_disable, + .is_enabled = qcom_clk_ref_is_enabled, +}; + +static int qcom_clk_ref_register(struct device *dev, struct regmap *regmap, + struct qcom_clk_ref *clk_refs, + const struct qcom_clk_ref_desc * const *descs, + size_t num_clk_refs) +{ + const struct qcom_clk_ref_desc *desc; + struct clk_init_data init_data = {}; + struct qcom_clk_ref *clk_ref; + size_t clk_idx; + unsigned int i; + int ret; + + for (clk_idx = 0; clk_idx < num_clk_refs; clk_idx++) { + clk_ref = &clk_refs[clk_idx]; + desc = descs[clk_idx]; + + /* Skip unpopulated indices; the array is indexed by clock ID. */ + if (!desc) + continue; + + if (WARN_ON(!desc->name)) + continue; + + clk_ref->regmap = regmap; + clk_ref->desc = *desc; + + if (clk_ref->desc.num_regulators) { + clk_ref->regulators = devm_kcalloc(dev, clk_ref->desc.num_regulators, + sizeof(*clk_ref->regulators), + GFP_KERNEL); + if (!clk_ref->regulators) + return -ENOMEM; + + for (i = 0; i < clk_ref->desc.num_regulators; i++) + clk_ref->regulators[i].supply = + clk_ref->desc.regulator_names[i]; + + ret = devm_regulator_bulk_get(dev, clk_ref->desc.num_regulators, + clk_ref->regulators); + if (ret) + return dev_err_probe(dev, ret, + "Failed to get regulators for %s\n", + clk_ref->desc.name); + } + + init_data.name = clk_ref->desc.name; + init_data.parent_data = &qcom_clk_ref_parent_data; + init_data.num_parents = 1; + init_data.ops = &qcom_clk_ref_ops; + clk_ref->hw.init = &init_data; + + ret = devm_clk_hw_register(dev, &clk_ref->hw); + if (ret) + return ret; + } + + return 0; +} + +static struct clk_hw *qcom_clk_ref_provider_get(struct of_phandle_args *clkspec, void *data) +{ + struct qcom_clk_ref_provider *provider = data; + unsigned int idx = clkspec->args[0]; + + if (idx >= provider->num_refs) + return ERR_PTR(-EINVAL); + + if (!provider->refs[idx].regmap) + return ERR_PTR(-ENOENT); + + return &provider->refs[idx].hw; +} + +int qcom_clk_ref_probe(struct platform_device *pdev, + const struct regmap_config *config, + const struct qcom_clk_ref_desc * const *descs, + size_t num_clk_refs) +{ + struct qcom_clk_ref_provider *provider; + struct device *dev = &pdev->dev; + struct regmap *regmap; + void __iomem *base; + int ret; + + base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(base)) + return PTR_ERR(base); + + regmap = devm_regmap_init_mmio(dev, base, config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + provider = devm_kzalloc(dev, struct_size(provider, refs, num_clk_refs), + GFP_KERNEL); + if (!provider) + return -ENOMEM; + + provider->num_refs = num_clk_refs; + + ret = qcom_clk_ref_register(dev, regmap, provider->refs, descs, + provider->num_refs); + if (ret) + return ret; + + return devm_of_clk_add_hw_provider(dev, qcom_clk_ref_provider_get, provider); +} +EXPORT_SYMBOL_GPL(qcom_clk_ref_probe); diff --git a/include/linux/clk/qcom.h b/include/linux/clk/qcom.h new file mode 100644 index 000000000000..11ac2d42ff9e --- /dev/null +++ b/include/linux/clk/qcom.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2026, Qualcomm Technologies, Inc. and/or its subsidiaries. + */ + +#ifndef __LINUX_CLK_QCOM_H +#define __LINUX_CLK_QCOM_H + +#include <linux/clk-provider.h> +#include <linux/errno.h> +#include <linux/kconfig.h> +#include <linux/regmap.h> +#include <linux/types.h> + +struct device; +struct platform_device; +struct regulator_bulk_data; + +/** + * struct qcom_clk_ref_desc - descriptor for a clkref_en gate clock + * @name: clock name exposed to the common clock framework + * @offset: clkref_en register offset from the block base + * @regulator_names: optional supply names enabled while preparing the clock + * @num_regulators: number of entries in @regulator_names + */ +struct qcom_clk_ref_desc { + const char *name; + u32 offset; + const char * const *regulator_names; + unsigned int num_regulators; +}; + +/** + * struct qcom_clk_ref - per-clock data for a clkref_en gate clock + * @hw: common clock framework hardware clock handle + * @regmap: register map backing the clkref_en register + * @desc: clock descriptor copied at registration time + * @regulators: optional bulk regulator handles for @desc.regulator_names + */ +struct qcom_clk_ref { + struct clk_hw hw; + struct regmap *regmap; + struct qcom_clk_ref_desc desc; + struct regulator_bulk_data *regulators; +}; + +#if IS_ENABLED(CONFIG_COMMON_CLK_QCOM) + +int qcom_clk_ref_probe(struct platform_device *pdev, + const struct regmap_config *config, + const struct qcom_clk_ref_desc * const *descs, + size_t num_clk_refs); + +#else + +static inline int +qcom_clk_ref_probe(struct platform_device *pdev, + const struct regmap_config *config, + const struct qcom_clk_ref_desc * const *descs, + size_t num_clk_refs) +{ + return -EOPNOTSUPP; +} + +#endif + +#endif -- 2.34.1
