2023-04-14 18:15:03

by David Yang

[permalink] [raw]
Subject: [PATCH 0/2] clk: Add basic register clock controller

These clocks were provided in `include/linux/clk-provider.h`, but lacks DT
bindings. Add a clock controller to avoid operation conflict on same
register.

*** BLURB HERE ***

David Yang (2):
dt-bindings: clock: Add reg-clock-controller
clk: Add basic register clock controller

.../bindings/clock/reg-clock-controller.yaml | 245 +++++++
drivers/clk/Makefile | 1 +
drivers/clk/clk-reg.c | 638 ++++++++++++++++++
3 files changed, 884 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
create mode 100644 drivers/clk/clk-reg.c


base-commit: 7a934f4bd7d6f9da84c8812da3ba42ee10f5778e
--
2.39.2


2023-04-14 18:15:24

by David Yang

[permalink] [raw]
Subject: [PATCH 2/2] clk: Add basic register clock controller

These clocks were provided in `include/linux/clk-provider.h`, but lacks DT
bindings. Add a clock controller to avoid operation conflict on same
register.

Signed-off-by: David Yang <[email protected]>
---
drivers/clk/Makefile | 1 +
drivers/clk/clk-reg.c | 638 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 639 insertions(+)
create mode 100644 drivers/clk/clk-reg.c

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index e3ca0d058a25..9468b2028a5b 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_COMMON_CLK) += clk-fractional-divider.o
obj-$(CONFIG_COMMON_CLK) += clk-gpio.o
ifeq ($(CONFIG_OF), y)
obj-$(CONFIG_COMMON_CLK) += clk-conf.o
+obj-$(CONFIG_COMMON_CLK) += clk-reg.o
endif

# hardware specific clock types
diff --git a/drivers/clk/clk-reg.c b/drivers/clk/clk-reg.c
new file mode 100644
index 000000000000..a115921a9cbd
--- /dev/null
+++ b/drivers/clk/clk-reg.c
@@ -0,0 +1,638 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/*
+ * Copyright (c) 2023 David Yang
+ *
+ * Simple straight-forward register clocks bindings
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_clk.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+
+struct regclk_ctrl {
+ spinlock_t lock;
+
+ void __iomem *base;
+ struct reset_controller_dev rcdev;
+ bool rst_set_to_disable;
+};
+
+struct regclk_flag {
+ const char *prop;
+ unsigned long flag;
+};
+
+static const struct regclk_flag regclk_flags[] = {
+ { "set-rate-gate", CLK_SET_RATE_GATE },
+ { "set-parent-gate", CLK_SET_PARENT_GATE },
+ { "set-rate-parent", CLK_SET_RATE_PARENT },
+ { "ignore-unused", CLK_IGNORE_UNUSED },
+ { "get-rate-nocache", CLK_GET_RATE_NOCACHE },
+ { "set-rate-no-reparent", CLK_SET_RATE_NO_REPARENT },
+ { "get-accuracy-nocache", CLK_GET_ACCURACY_NOCACHE },
+ { "recalc-new-rates", CLK_RECALC_NEW_RATES },
+ { "set-rate-ungate", CLK_SET_RATE_UNGATE },
+ { "critical", CLK_IS_CRITICAL },
+ { "ops-parent-enable", CLK_OPS_PARENT_ENABLE },
+ { "duty-cycle-parent", CLK_DUTY_CYCLE_PARENT },
+ { }
+};
+
+static const struct regclk_flag regclk_gate_flags[] = {
+ { "set-to-disable", CLK_GATE_SET_TO_DISABLE },
+ { "hiword-mask", CLK_GATE_HIWORD_MASK },
+ { "big-endian", CLK_GATE_BIG_ENDIAN },
+ { }
+};
+
+static const struct regclk_flag regclk_divider_flags[] = {
+ { "one-based", CLK_DIVIDER_ONE_BASED },
+ { "power-of-two", CLK_DIVIDER_POWER_OF_TWO },
+ { "allow-zero", CLK_DIVIDER_ALLOW_ZERO },
+ { "hiword-mask", CLK_DIVIDER_HIWORD_MASK },
+ { "round-closest", CLK_DIVIDER_ROUND_CLOSEST },
+ { "read-only", CLK_DIVIDER_READ_ONLY },
+ { "max-at-zero", CLK_DIVIDER_MAX_AT_ZERO },
+ { "big-endian", CLK_DIVIDER_BIG_ENDIAN },
+ { }
+};
+
+static const struct regclk_flag regclk_mux_flags[] = {
+ { "index-one", CLK_MUX_INDEX_ONE },
+ { "index-bit", CLK_MUX_INDEX_BIT },
+ { "hiword-mask", CLK_MUX_HIWORD_MASK },
+ { "read-only", CLK_MUX_READ_ONLY },
+ { "round-closest", CLK_MUX_ROUND_CLOSEST },
+ { "big-endian", CLK_MUX_BIG_ENDIAN },
+ { }
+};
+
+static const struct regclk_flag regclk_fractional_divider_flags[] = {
+ { "zero-based", CLK_FRAC_DIVIDER_ZERO_BASED },
+ { "big-endian", CLK_FRAC_DIVIDER_BIG_ENDIAN },
+ { "power-of-two-ps", CLK_FRAC_DIVIDER_POWER_OF_TWO_PS },
+ { }
+};
+
+static unsigned long
+regclk_get_flags(struct device_node *np, const struct regclk_flag *defs)
+{
+ unsigned long flags = 0;
+
+ for (int i = 0; defs[i].prop; i++)
+ if (of_property_read_bool(np, defs[i].prop))
+ flags |= defs[i].flag;
+
+ return flags;
+}
+
+static const char *regclk_name(struct device_node *np)
+{
+ const char *name;
+
+ if (!of_property_read_string(np, "clock-output-name", &name))
+ return name;
+
+ return of_node_full_name(np);
+}
+
+static struct clk_hw *
+regclk_register_gate(struct device_node *np, struct regclk_ctrl *priv)
+{
+ const char *name;
+ const char *parent_name;
+ unsigned long flags;
+ void __iomem *reg;
+ u32 bit_idx;
+ unsigned long clk_gate_flags;
+
+ const char *property;
+ struct clk_hw *hw;
+ struct clk_hw *retptr;
+ int ret;
+
+ reg = of_iomap(np, 0);
+ if (!reg)
+ return ERR_PTR(-ENOMEM);
+ name = regclk_name(np);
+ if (!name)
+ return ERR_PTR(-EINVAL);
+
+ property = "bit-index";
+ if (of_property_read_u32(np, property, &bit_idx))
+ goto err_property;
+
+ parent_name = of_clk_get_parent_name(np, 0);
+ flags = regclk_get_flags(np, regclk_flags);
+ clk_gate_flags = regclk_get_flags(np, regclk_gate_flags);
+
+ hw = __clk_hw_register_gate(NULL, np, name, parent_name,
+ NULL, NULL, flags, reg, bit_idx,
+ clk_gate_flags, &priv->lock);
+ if (IS_ERR(hw))
+ return hw;
+
+ ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
+ if (ret) {
+ retptr = ERR_PTR(ret);
+ goto err_register;
+ }
+
+ return hw;
+
+err_register:
+ clk_hw_unregister(hw);
+ return retptr;
+
+err_property:
+ pr_err("%s: clock %s missing required property \"%s\"\n",
+ __func__, name, property);
+ return ERR_PTR(-EINVAL);
+}
+
+static struct clk_hw *
+regclk_register_divider(struct device_node *np, struct regclk_ctrl *priv)
+{
+ const char *name;
+ const char *parent_name;
+ unsigned long flags;
+ void __iomem *reg;
+ u32 shift;
+ u32 width;
+ unsigned long clk_divider_flags;
+ struct clk_div_table *table = NULL;
+
+ struct property *prop;
+ const char *property;
+ struct clk_hw *hw;
+ struct clk_hw *retptr;
+ int ret;
+
+ reg = of_iomap(np, 0);
+ if (!reg)
+ return ERR_PTR(-ENOMEM);
+
+ name = regclk_name(np);
+ if (!name)
+ return ERR_PTR(-EINVAL);
+
+ property = "shift";
+ if (of_property_read_u32(np, property, &shift))
+ goto err_property;
+ property = "width";
+ if (of_property_read_u32(np, property, &width))
+ goto err_property;
+
+ prop = of_find_property(np, "dividers", NULL);
+ if (prop) {
+ unsigned int len = (prop->length / sizeof(u32) + 1) / 2;
+
+ table = kmalloc_array(len + 1, sizeof(*table), GFP_KERNEL);
+ if (!table)
+ return ERR_PTR(-ENOMEM);
+
+ for (unsigned int i = 0; i <= len; i++) {
+ u32 val;
+ u32 div;
+
+ if (of_property_read_u32_index(np, "dividers",
+ 2 * i + 0, &val)) {
+ retptr = ERR_PTR(-EINVAL);
+ goto err_table;
+ }
+ if (of_property_read_u32_index(np, "dividers",
+ 2 * i + 1, &div)) {
+ if (i == len)
+ div = 0;
+ retptr = ERR_PTR(-EINVAL);
+ goto err_table;
+ }
+
+ table[i].val = val;
+ table[i].div = div;
+ }
+
+ memset(&table[len], 0, sizeof(table[len]));
+ }
+
+ parent_name = of_clk_get_parent_name(np, 0);
+ flags = regclk_get_flags(np, regclk_flags);
+ clk_divider_flags = regclk_get_flags(np, regclk_divider_flags);
+
+ hw = __clk_hw_register_divider(NULL, np, name, parent_name,
+ NULL, NULL, flags, reg, shift, width,
+ clk_divider_flags, table, &priv->lock);
+ if (IS_ERR(hw)) {
+ retptr = hw;
+ goto err_table;
+ }
+
+ ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
+ if (ret) {
+ retptr = ERR_PTR(ret);
+ goto err_register;
+ }
+
+ return hw;
+
+err_register:
+ clk_hw_unregister(hw);
+err_table:
+ kfree(table);
+ return retptr;
+
+err_property:
+ pr_err("%s: clock %s missing required property \"%s\"\n",
+ __func__, name, property);
+ return ERR_PTR(-EINVAL);
+}
+
+static struct clk_hw *
+regclk_register_mux(struct device_node *np, struct regclk_ctrl *priv)
+{
+ const char *name;
+ u8 num_parents;
+ const char **parent_names;
+ unsigned long flags;
+ void __iomem *reg;
+ u32 shift;
+ u32 mask;
+ unsigned long clk_mux_flags;
+ u32 *table;
+
+ const char *property;
+ struct clk_hw *hw;
+ struct clk_hw *retptr;
+ int ret;
+
+ reg = of_iomap(np, 0);
+ if (!reg)
+ return ERR_PTR(-ENOMEM);
+ name = regclk_name(np);
+ if (!name)
+ return ERR_PTR(-EINVAL);
+
+ property = "shift";
+ if (of_property_read_u32(np, property, &shift))
+ goto err_property;
+ property = "mask";
+ if (of_property_read_u32(np, property, &mask))
+ goto err_property;
+
+ num_parents = of_clk_get_parent_count(np);
+
+ parent_names = kmalloc_array(num_parents, sizeof(*parent_names),
+ GFP_KERNEL);
+ if (!parent_names)
+ return ERR_PTR(-ENOMEM);
+ for (int i = 0; i < num_parents; i++) {
+ parent_names[i] = of_clk_get_parent_name(np, i);
+ if (!parent_names[i]) {
+ retptr = ERR_PTR(-EINVAL);
+ goto err_parents;
+ }
+ }
+
+ table = kmalloc_array(num_parents, sizeof(*table), GFP_KERNEL);
+ if (!table) {
+ retptr = ERR_PTR(-ENOMEM);
+ goto err_parents;
+ }
+ for (int i = 0; i < num_parents; i++) {
+ if (of_property_read_u32(np, "table", &table[i])) {
+ retptr = ERR_PTR(-EINVAL);
+ goto err_table;
+ }
+ }
+
+ flags = regclk_get_flags(np, regclk_flags);
+ clk_mux_flags = regclk_get_flags(np, regclk_mux_flags);
+
+ hw = __clk_hw_register_mux(NULL, np, name, num_parents, parent_names,
+ NULL, NULL, flags, reg, shift, mask,
+ clk_mux_flags, table, &priv->lock);
+ if (IS_ERR(hw))
+ goto err_table;
+
+ ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
+ if (ret) {
+ retptr = ERR_PTR(ret);
+ goto err_register;
+ }
+
+ return hw;
+
+err_register:
+ clk_hw_unregister(hw);
+err_table:
+ kfree(table);
+err_parents:
+ kfree(parent_names);
+ return retptr;
+
+err_property:
+ pr_err("%s: clock %s missing required property \"%s\"\n",
+ __func__, name, property);
+ return ERR_PTR(-EINVAL);
+}
+
+static struct clk_hw *
+regclk_register_fractional_divider(struct device_node *np, struct regclk_ctrl *priv)
+{
+ const char *name;
+ const char *parent_name;
+ unsigned long flags;
+ void __iomem *reg;
+ u32 mshift;
+ u32 mwidth;
+ u32 nshift;
+ u32 nwidth;
+ unsigned long clk_divider_flags;
+
+ const char *property;
+ struct clk_hw *hw;
+ struct clk_hw *retptr;
+ int ret;
+
+ reg = of_iomap(np, 0);
+ if (!reg)
+ return ERR_PTR(-ENOMEM);
+ name = regclk_name(np);
+ if (!name)
+ return ERR_PTR(-EINVAL);
+
+ property = "numerator-shift";
+ if (of_property_read_u32(np, property, &mshift))
+ goto err_property;
+ property = "numerator-width";
+ if (of_property_read_u32(np, property, &mwidth))
+ goto err_property;
+ property = "denominator-shift";
+ if (of_property_read_u32(np, property, &nshift))
+ goto err_property;
+ property = "denominator-width";
+ if (of_property_read_u32(np, property, &nwidth))
+ goto err_property;
+
+ parent_name = of_clk_get_parent_name(np, 0);
+ flags = regclk_get_flags(np, regclk_flags);
+ clk_divider_flags = regclk_get_flags(np, regclk_fractional_divider_flags);
+
+ hw = clk_hw_register_fractional_divider(NULL, name, parent_name,
+ flags, reg, mshift, mwidth,
+ nshift, nwidth,
+ clk_divider_flags, &priv->lock);
+ if (IS_ERR(hw))
+ return hw;
+
+ ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
+ if (ret) {
+ retptr = ERR_PTR(ret);
+ goto err_register;
+ }
+
+ return hw;
+
+err_register:
+ clk_hw_unregister(hw);
+ return retptr;
+
+err_property:
+ pr_err("%s: clock %s missing required property \"%s\"\n",
+ __func__, name, property);
+ return ERR_PTR(-EINVAL);
+}
+
+/** regclk **/
+
+static void regclk_unsetup(struct device_node *np)
+{
+ struct clk_hw *hw = np->data;
+
+ if (!hw)
+ return;
+
+ if (of_device_is_compatible(np, "gate-clock"))
+ clk_hw_unregister_gate(hw);
+ else if (of_device_is_compatible(np, "divider-clock"))
+ clk_hw_unregister_divider(hw);
+ else if (of_device_is_compatible(np, "mux-clock"))
+ clk_hw_unregister_mux(hw);
+ else if (of_device_is_compatible(np, "fractional-divider-clock"))
+ clk_hw_unregister_fractional_divider(hw);
+}
+
+static int regclk_setup(struct device_node *np, struct regclk_ctrl *priv)
+{
+ struct clk_hw *hw = np->data;
+
+ if (of_device_is_compatible(np, "gate-clock"))
+ hw = regclk_register_gate(np, priv);
+ else if (of_device_is_compatible(np, "divider-clock"))
+ hw = regclk_register_divider(np, priv);
+ else if (of_device_is_compatible(np, "mux-clock"))
+ hw = regclk_register_mux(np, priv);
+ else if (of_device_is_compatible(np, "fractional-divider-clock"))
+ hw = regclk_register_fractional_divider(np, priv);
+ else {
+ pr_warn("%s: starnge node %s ...\n",
+ __func__, of_node_full_name(np));
+ return 0;
+ }
+
+ if (IS_ERR(hw)) {
+ int ret = PTR_ERR(hw);
+
+ pr_err("%s: cannot register clock %s, ret %d\n",
+ __func__, of_node_full_name(np), ret);
+ return ret;
+ }
+
+ np->data = hw;
+ return 0;
+}
+
+/** regclk_reset **/
+
+#if IS_ENABLED(CONFIG_RESET_CONTROLLER)
+static int
+regclk_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+ struct regclk_ctrl *priv = container_of(rcdev, struct regclk_ctrl, rcdev);
+ unsigned long flags;
+ u32 offset = id >> 5;
+ u8 bit = id & 0x1f;
+ u32 val;
+
+ if (WARN_ON(!priv->base))
+ return 0;
+
+ spin_lock_irqsave(&priv->lock, flags);
+
+ val = readl(priv->base + offset);
+ if (priv->rst_set_to_disable)
+ val &= ~BIT(bit);
+ else
+ val |= BIT(bit);
+ writel(val, priv->base + offset);
+
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ return 0;
+}
+
+static int
+regclk_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+ struct regclk_ctrl *priv = container_of(rcdev, struct regclk_ctrl, rcdev);
+ unsigned long flags;
+ u32 offset = id >> 5;
+ u8 bit = id & 0x1f;
+ u32 val;
+
+ if (WARN_ON(!priv->base))
+ return 0;
+
+ spin_lock_irqsave(&priv->lock, flags);
+
+ val = readl(priv->base + offset);
+ if (priv->rst_set_to_disable)
+ val |= BIT(bit);
+ else
+ val &= ~BIT(bit);
+ writel(val, priv->base + offset);
+
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ return 0;
+}
+
+static const struct reset_control_ops regclk_reset_ops = {
+ .assert = regclk_reset_assert,
+ .deassert = regclk_reset_deassert,
+};
+
+static int regclk_reset_of_xlate(struct reset_controller_dev *rcdev,
+ const struct of_phandle_args *reset_spec)
+{
+ return (reset_spec->args[0] << 5) | (reset_spec->args[1] & 0x1f);
+}
+
+static void regclk_reset_unsetup(struct device_node *np)
+{
+ struct regclk_ctrl *priv = np->data;
+
+ reset_controller_unregister(&priv->rcdev);
+}
+
+static int regclk_reset_setup(struct device_node *np, struct regclk_ctrl *priv)
+{
+ priv->base = of_iomap(np, 0);
+ priv->rst_set_to_disable = of_property_read_bool(np, "set-to-disable");
+
+ /* register no matter whether reg exists, to detect dts bug */
+ priv->rcdev.ops = &regclk_reset_ops;
+ priv->rcdev.of_node = np;
+ priv->rcdev.of_reset_n_cells = 2;
+ priv->rcdev.of_xlate = regclk_reset_of_xlate;
+ return reset_controller_register(&priv->rcdev);
+}
+#else
+static void regclk_reset_unsetup(struct device_node *np)
+{
+}
+
+static int regclk_reset_setup(struct device_node *np, struct regclk_ctrl *priv)
+{
+ return 0;
+}
+#endif
+
+/** regclk_ctrl **/
+
+static void regclk_ctrl_unsetup(struct device_node *np)
+{
+ struct device_node *child;
+
+ regclk_reset_unsetup(np);
+
+ for_each_child_of_node(np, child)
+ regclk_unsetup(child);
+
+ kfree(np->data);
+}
+
+static int regclk_ctrl_setup(struct device_node *np)
+{
+ struct regclk_ctrl *priv;
+ struct device_node *child;
+ int ret;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ spin_lock_init(&priv->lock);
+ np->data = priv;
+
+ for_each_child_of_node(np, child) {
+ ret = regclk_setup(child, priv);
+ if (ret)
+ goto err;
+ }
+
+ ret = regclk_reset_setup(np, priv);
+ if (ret)
+ goto err;
+
+ return 0;
+
+err:
+ regclk_ctrl_unsetup(np);
+ return ret;
+}
+
+/** driver **/
+
+static void __init regclk_ctrl_init(struct device_node *np)
+{
+ regclk_ctrl_setup(np);
+}
+CLK_OF_DECLARE(regclk_ctrl, "reg-clock-controller", regclk_ctrl_init);
+
+static int regclk_ctrl_remove(struct platform_device *pdev)
+{
+ regclk_ctrl_unsetup(pdev->dev.of_node);
+
+ return 0;
+}
+
+/* This function is not executed when regclk_ctrl_init succeeded. */
+static int regclk_ctrl_probe(struct platform_device *pdev)
+{
+ return regclk_ctrl_setup(pdev->dev.of_node);
+}
+
+static const struct of_device_id regclk_ctrl_ids[] = {
+ { .compatible = "reg-clock-controller" },
+ { }
+};
+
+static struct platform_driver regclk_ctrl_driver = {
+ .driver = {
+ .name = "reg_clk_controller",
+ .of_match_table = regclk_ctrl_ids,
+ },
+ .probe = regclk_ctrl_probe,
+ .remove = regclk_ctrl_remove,
+};
+builtin_platform_driver(regclk_ctrl_driver);
--
2.39.2

2023-04-14 18:15:54

by David Yang

[permalink] [raw]
Subject: [PATCH 1/2] dt-bindings: clock: Add reg-clock-controller

Add DT bindings documentation for reg-clock-controller, collection of
basic clocks common to many platforms.

Signed-off-by: David Yang <[email protected]>
---
.../bindings/clock/reg-clock-controller.yaml | 245 ++++++++++++++++++
1 file changed, 245 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/reg-clock-controller.yaml

diff --git a/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
new file mode 100644
index 000000000000..a6a7e0b05821
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
@@ -0,0 +1,245 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/reg-clock-controller.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Simple straight-forward register-based clocks
+
+maintainers:
+ - David Yang <[email protected]>
+
+description: |
+ Basic clocks common to many platforms.
+
+ If your clocks don't fit into these catagories, simply create your clock
+ controller. This driver normally work well with other controllers as long as
+ they operate on different registers.
+
+ See linux/clk-provider.h for details about properties for each type of clock.
+
+properties:
+ compatible:
+ enum:
+ - reg-clock-controller
+
+ ranges: true
+
+ '#address-cells':
+ const: 1
+
+ '#size-cells':
+ const: 1
+
+required:
+ - compatible
+ - ranges
+ - '#address-cells'
+ - '#size-cells'
+
+patternProperties:
+ ".*gate-clock@.*":
+ type: object
+
+ description: |
+ Clock which can gate its output.
+
+ properties:
+ compatible:
+ const: gate-clock
+
+ reg:
+ maxItems: 1
+
+ '#clock-cells':
+ const: 0
+
+ clocks:
+ maxItems: 1
+ description:
+ Parent clock.
+
+ clock-output-name:
+ maxItems: 1
+
+ bit-index:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Bit index which controls the output.
+
+ required:
+ - compatible
+ - reg
+ - '#clock-cells'
+ - bit-index
+
+ additionalProperties: false
+
+ ".*divider-clock@.*":
+ type: object
+
+ description: |
+ Clock with an adjustable divider affecting its output frequency.
+
+ properties:
+ compatible:
+ const: divider-clock
+
+ reg:
+ maxItems: 1
+
+ '#clock-cells':
+ const: 0
+
+ clocks:
+ description:
+ Parent clocks.
+
+ clock-output-name:
+ maxItems: 1
+
+ shift:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Shift to the divider bit field.
+
+ width:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Width of the divider bit field.
+
+ dividers:
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+ description:
+ Array of value/divider pairs.
+
+ required:
+ - compatible
+ - reg
+ - '#clock-cells'
+ - shift
+ - width
+
+ additionalProperties: false
+
+ ".*mux-clock@.*":
+ type: object
+
+ description: |
+ Clock with multiple selectable parents.
+
+ properties:
+ compatible:
+ const: mux-clock
+
+ reg:
+ maxItems: 1
+
+ '#clock-cells':
+ const: 0
+
+ clocks:
+ minItems: 1
+ description:
+ Parent clock.
+
+ clock-output-name:
+ maxItems: 1
+
+ shift:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Shift to multiplexer bit field.
+
+ mask:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Mask of mutliplexer bit field.
+
+ table:
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+ description:
+ Array of register values corresponding to the parent index.
+
+ required:
+ - compatible
+ - reg
+ - '#clock-cells'
+ - shift
+ - mask
+
+ additionalProperties: false
+
+ ".*fractional-divider-clock@.*":
+ type: object
+
+ description: |
+ Clock with adjustable fractional divider affecting its output frequency.
+
+ properties:
+ compatible:
+ const: fractional_divider-clock
+
+ reg:
+ maxItems: 1
+
+ '#clock-cells':
+ const: 0
+
+ clocks:
+ maxItems: 1
+ description:
+ Parent clock.
+
+ clock-output-name:
+ maxItems: 1
+
+ numerator-shift:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Shift to the numerator bit field.
+
+ numerator-width:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Width of the numerator bit field.
+
+ denominator-shift:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Shift to the denominator bit field.
+
+ denominator-width:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Width of the denominator bit field.
+
+ required:
+ - compatible
+ - reg
+ - '#clock-cells'
+ - numerator-shift
+ - numerator-width
+ - denominator-shift
+ - denominator-width
+
+ additionalProperties: false
+
+additionalProperties: true
+
+examples:
+ - |
+ clks: reg-clk-ctrl@ffff0000 {
+ compatible = "reg-clock-controller";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0 0xffff0000 0x1000>;
+
+ my_clk: gate-clock@cc-3 {
+ compatible = "gate-clock";
+ #clock-cells = <0>;
+ reg = <0xcc 4>;
+ bit-index = <3>;
+ clock-output-name = "my-clk";
+ };
+ };
--
2.39.2

2023-04-14 21:16:16

by Krzysztof Kozlowski

[permalink] [raw]
Subject: Re: [PATCH 1/2] dt-bindings: clock: Add reg-clock-controller

On 14/04/2023 20:12, David Yang wrote:
> Add DT bindings documentation for reg-clock-controller, collection of
> basic clocks common to many platforms.
>
> Signed-off-by: David Yang <[email protected]>
> ---
> .../bindings/clock/reg-clock-controller.yaml | 245 ++++++++++++++++++
> 1 file changed, 245 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
>
> diff --git a/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> new file mode 100644
> index 000000000000..a6a7e0b05821
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> @@ -0,0 +1,245 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/clock/reg-clock-controller.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Simple straight-forward register-based clocks
> +
> +maintainers:
> + - David Yang <[email protected]>
> +
> +description: |
> + Basic clocks common to many platforms.
> +
> + If your clocks don't fit into these catagories, simply create your clock

typo: categories

> + controller. This driver normally work well with other controllers as long as
> + they operate on different registers.
> +
> + See linux/clk-provider.h for details about properties for each type of clock.

Describe here what is this device, what such simple clock controller
represents.

> +
> +properties:
> + compatible:
> + enum:
> + - reg-clock-controller
> +
> + ranges: true
> +
> + '#address-cells':
> + const: 1
> +
> + '#size-cells':
> + const: 1
> +
> +required:
> + - compatible
> + - ranges
> + - '#address-cells'
> + - '#size-cells'

required goes after patternProperties.

> +
> +patternProperties:
> + ".*gate-clock@.*":

"gate-clock@" should be equivalent. However this should be just "clock".

> + type: object
> +
> + description: |

Do not need '|' unless you need to preserve formatting.

> + Clock which can gate its output.
> +
> + properties:
> + compatible:
> + const: gate-clock
> +
> + reg:
> + maxItems: 1
> +
> + '#clock-cells':
> + const: 0
> +
> + clocks:
> + maxItems: 1
> + description:
> + Parent clock.
> +
> + clock-output-name:

names

Don't create your own properties.

> + maxItems: 1
> +
> + bit-index:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Bit index which controls the output.

I suggest to use same property as nvme, so bits.

> +
> + required:
> + - compatible
> + - reg
> + - '#clock-cells'
> + - bit-index
> +
> + additionalProperties: false
> +
> + ".*divider-clock@.*":
> + type: object
> +
> + description: |
> + Clock with an adjustable divider affecting its output frequency.
> +
> + properties:
> + compatible:
> + const: divider-clock
> +
> + reg:
> + maxItems: 1
> +
> + '#clock-cells':
> + const: 0
> +
> + clocks:
> + description:
> + Parent clocks.
> +
> + clock-output-name:
> + maxItems: 1
> +
> + shift:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Shift to the divider bit field.
> +
> + width:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Width of the divider bit field.
> +
> + dividers:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + description:
> + Array of value/divider pairs.

Then it looks like matrix.

> +
> + required:
> + - compatible
> + - reg
> + - '#clock-cells'
> + - shift
> + - width
> +
> + additionalProperties: false
> +
> + ".*mux-clock@.*":
> + type: object
> +
> + description: |
> + Clock with multiple selectable parents.
> +
> + properties:
> + compatible:
> + const: mux-clock
> +
> + reg:
> + maxItems: 1
> +
> + '#clock-cells':
> + const: 0
> +
> + clocks:
> + minItems: 1
> + description:
> + Parent clock.
> +
> + clock-output-name:
> + maxItems: 1
> +
> + shift:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Shift to multiplexer bit field.
> +
> + mask:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Mask of mutliplexer bit field.
> +
> + table:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + description:
> + Array of register values corresponding to the parent index.
> +
> + required:
> + - compatible
> + - reg
> + - '#clock-cells'
> + - shift
> + - mask
> +
> + additionalProperties: false
> +
> + ".*fractional-divider-clock@.*":
> + type: object
> +
> + description: |
> + Clock with adjustable fractional divider affecting its output frequency.
> +
> + properties:
> + compatible:
> + const: fractional_divider-clock
> +
> + reg:
> + maxItems: 1
> +
> + '#clock-cells':
> + const: 0
> +
> + clocks:
> + maxItems: 1
> + description:
> + Parent clock.
> +
> + clock-output-name:
> + maxItems: 1
> +
> + numerator-shift:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Shift to the numerator bit field.
> +
> + numerator-width:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Width of the numerator bit field.
> +
> + denominator-shift:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Shift to the denominator bit field.
> +
> + denominator-width:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Width of the denominator bit field.
> +
> + required:
> + - compatible
> + - reg
> + - '#clock-cells'
> + - numerator-shift
> + - numerator-width
> + - denominator-shift
> + - denominator-width
> +
> + additionalProperties: false
> +
> +additionalProperties: true

No, come on. This must be false.

> +
> +examples:
> + - |
> + clks: reg-clk-ctrl@ffff0000 {

Names should be generic, so clock-controller

Drop the label.

> + compatible = "reg-clock-controller";
> + #address-cells = <1>;
> + #size-cells = <1>;
> + ranges = <0 0xffff0000 0x1000>;
> +
> + my_clk: gate-clock@cc-3 {

Drop label.

That's a new unit address to me. Did I miss a change in DT spec?

> + compatible = "gate-clock";
> + #clock-cells = <0>;
> + reg = <0xcc 4>;

reg is after compatible.

> + bit-index = <3>;
> + clock-output-name = "my-clk";

Plus, test your patches. This fails testing...

> + };
> + };

Best regards,
Krzysztof

2023-04-17 13:16:04

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH 1/2] dt-bindings: clock: Add reg-clock-controller


On Sat, 15 Apr 2023 02:12:59 +0800, David Yang wrote:
> Add DT bindings documentation for reg-clock-controller, collection of
> basic clocks common to many platforms.
>
> Signed-off-by: David Yang <[email protected]>
> ---
> .../bindings/clock/reg-clock-controller.yaml | 245 ++++++++++++++++++
> 1 file changed, 245 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
>

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/clock/reg-clock-controller.example.dtb: reg-clk-ctrl@ffff0000: 'gate-clock@cc-3' does not match any of the regexes: '.*-names$', '.*-supply$', '^#.*-cells$', '^#[a-zA-Z0-9,+\\-._]{0,63}$', '^[a-zA-Z0-9][a-zA-Z0-9,+\\-._]{0,63}$', '^[a-zA-Z][a-zA-Z0-9,+\\-._]{0,63}@[0-9a-fA-F]+(,[0-9a-fA-F]+)*$', '^__.*__$', 'pinctrl-[0-9]+'
From schema: /usr/local/lib/python3.10/dist-packages/dtschema/schemas/dt-core.yaml

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/[email protected]

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

2023-04-17 17:54:16

by David Yang

[permalink] [raw]
Subject: Re: [PATCH 1/2] dt-bindings: clock: Add reg-clock-controller

Krzysztof Kozlowski <[email protected]> 于2023年4月15日周六 05:08写道:
>
> On 14/04/2023 20:12, David Yang wrote:
> > Add DT bindings documentation for reg-clock-controller, collection of
> > basic clocks common to many platforms.
> >
> > Signed-off-by: David Yang <[email protected]>
> > ---
> > .../bindings/clock/reg-clock-controller.yaml | 245 ++++++++++++++++++
> > 1 file changed, 245 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> > new file mode 100644
> > index 000000000000..a6a7e0b05821
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> > @@ -0,0 +1,245 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/clock/reg-clock-controller.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Simple straight-forward register-based clocks
> > +
> > +maintainers:
> > + - David Yang <[email protected]>
> > +
> > +description: |
> > + Basic clocks common to many platforms.
> > +
> > + If your clocks don't fit into these catagories, simply create your clock
>
> typo: categories

Fixed in v2.

>
> > + controller. This driver normally work well with other controllers as long as
> > + they operate on different registers.
> > +
> > + See linux/clk-provider.h for details about properties for each type of clock.
>
> Describe here what is this device, what such simple clock controller
> represents.

Description has been rewritten in v3, to describe the device.

>
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - reg-clock-controller
> > +
> > + ranges: true
> > +
> > + '#address-cells':
> > + const: 1
> > +
> > + '#size-cells':
> > + const: 1
> > +
> > +required:
> > + - compatible
> > + - ranges
> > + - '#address-cells'
> > + - '#size-cells'
>
> required goes after patternProperties.

Fixed in v2.

>
> > +
> > +patternProperties:
> > + ".*gate-clock@.*":
>
> "gate-clock@" should be equivalent. However this should be just "clock".

Fixed in v3.

>
> > + type: object
> > +
> > + description: |
>
> Do not need '|' unless you need to preserve formatting.

Fixed in v2.

>
> > + Clock which can gate its output.
> > +
> > + properties:
> > + compatible:
> > + const: gate-clock
> > +
> > + reg:
> > + maxItems: 1
> > +
> > + '#clock-cells':
> > + const: 0
> > +
> > + clocks:
> > + maxItems: 1
> > + description:
> > + Parent clock.
> > +
> > + clock-output-name:
>
> names
>
> Don't create your own properties.

Fixed in v2, "clock-output-names".

>
> > + maxItems: 1
> > +
> > + bit-index:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + Bit index which controls the output.
>
> I suggest to use same property as nvme, so bits.

Replaced with "bits" in v2.

>
> > +
> > + required:
> > + - compatible
> > + - reg
> > + - '#clock-cells'
> > + - bit-index
> > +
> > + additionalProperties: false
> > +
> > + ".*divider-clock@.*":
> > + type: object
> > +
> > + description: |
> > + Clock with an adjustable divider affecting its output frequency.
> > +
> > + properties:
> > + compatible:
> > + const: divider-clock
> > +
> > + reg:
> > + maxItems: 1
> > +
> > + '#clock-cells':
> > + const: 0
> > +
> > + clocks:
> > + description:
> > + Parent clocks.
> > +
> > + clock-output-name:
> > + maxItems: 1
> > +
> > + shift:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + Shift to the divider bit field.
> > +
> > + width:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + Width of the divider bit field.
> > +
> > + dividers:
> > + $ref: /schemas/types.yaml#/definitions/uint32-array
> > + description:
> > + Array of value/divider pairs.
>
> Then it looks like matrix.

This part of bindings has been (temporarily) removed from this series
since v2, to make it simpler.

>
> > +
> > + required:
> > + - compatible
> > + - reg
> > + - '#clock-cells'
> > + - shift
> > + - width
> > +
> > + additionalProperties: false
> > +
> > + ".*mux-clock@.*":
> > + type: object
> > +
> > + description: |
> > + Clock with multiple selectable parents.
> > +
> > + properties:
> > + compatible:
> > + const: mux-clock
> > +
> > + reg:
> > + maxItems: 1
> > +
> > + '#clock-cells':
> > + const: 0
> > +
> > + clocks:
> > + minItems: 1
> > + description:
> > + Parent clock.
> > +
> > + clock-output-name:
> > + maxItems: 1
> > +
> > + shift:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + Shift to multiplexer bit field.
> > +
> > + mask:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + Mask of mutliplexer bit field.
> > +
> > + table:
> > + $ref: /schemas/types.yaml#/definitions/uint32-array
> > + description:
> > + Array of register values corresponding to the parent index.
> > +
> > + required:
> > + - compatible
> > + - reg
> > + - '#clock-cells'
> > + - shift
> > + - mask
> > +
> > + additionalProperties: false
> > +
> > + ".*fractional-divider-clock@.*":
> > + type: object
> > +
> > + description: |
> > + Clock with adjustable fractional divider affecting its output frequency.
> > +
> > + properties:
> > + compatible:
> > + const: fractional_divider-clock
> > +
> > + reg:
> > + maxItems: 1
> > +
> > + '#clock-cells':
> > + const: 0
> > +
> > + clocks:
> > + maxItems: 1
> > + description:
> > + Parent clock.
> > +
> > + clock-output-name:
> > + maxItems: 1
> > +
> > + numerator-shift:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + Shift to the numerator bit field.
> > +
> > + numerator-width:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + Width of the numerator bit field.
> > +
> > + denominator-shift:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + Shift to the denominator bit field.
> > +
> > + denominator-width:
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + description:
> > + Width of the denominator bit field.
> > +
> > + required:
> > + - compatible
> > + - reg
> > + - '#clock-cells'
> > + - numerator-shift
> > + - numerator-width
> > + - denominator-shift
> > + - denominator-width
> > +
> > + additionalProperties: false
> > +
> > +additionalProperties: true
>
> No, come on. This must be false.

Fixed with "false" in v2.

>
> > +
> > +examples:
> > + - |
> > + clks: reg-clk-ctrl@ffff0000 {
>
> Names should be generic, so clock-controller
>
> Drop the label.

Dropped in v2.

>
> > + compatible = "reg-clock-controller";
> > + #address-cells = <1>;
> > + #size-cells = <1>;
> > + ranges = <0 0xffff0000 0x1000>;
> > +
> > + my_clk: gate-clock@cc-3 {
>
> Drop label.
>
> That's a new unit address to me. Did I miss a change in DT spec?

Dropped label in v2.

>
> > + compatible = "gate-clock";
> > + #clock-cells = <0>;
> > + reg = <0xcc 4>;
>
> reg is after compatible.
>
> > + bit-index = <3>;
> > + clock-output-name = "my-clk";
>
> Plus, test your patches. This fails testing...

Fix name error in v3.

>
> > + };
> > + };
>
> Best regards,
> Krzysztof
>

2023-04-17 20:51:25

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH 1/2] dt-bindings: clock: Add reg-clock-controller

On Sat, Apr 15, 2023 at 02:12:59AM +0800, David Yang wrote:
> Add DT bindings documentation for reg-clock-controller, collection of
> basic clocks common to many platforms.
>
> Signed-off-by: David Yang <[email protected]>
> ---
> .../bindings/clock/reg-clock-controller.yaml | 245 ++++++++++++++++++
> 1 file changed, 245 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
>
> diff --git a/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> new file mode 100644
> index 000000000000..a6a7e0b05821
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> @@ -0,0 +1,245 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/clock/reg-clock-controller.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Simple straight-forward register-based clocks

'simple' means extended one property at a time with little foresight. In
the end, 'simple' bindings are never simple. s/simple/generic/ as well.

When we first started the clock binding, we had exactly this. There's
still bindings for at least some of it. It turned out to be a bad
idea because it was difficult to get correct and complete. So this
binding is exactly what we don't want.

Rob

2023-04-17 21:42:14

by David Yang

[permalink] [raw]
Subject: Re: [PATCH 1/2] dt-bindings: clock: Add reg-clock-controller

Rob Herring <[email protected]> 于2023年4月18日周二 04:49写道:
>
> On Sat, Apr 15, 2023 at 02:12:59AM +0800, David Yang wrote:
> > Add DT bindings documentation for reg-clock-controller, collection of
> > basic clocks common to many platforms.
> >
> > Signed-off-by: David Yang <[email protected]>
> > ---
> > .../bindings/clock/reg-clock-controller.yaml | 245 ++++++++++++++++++
> > 1 file changed, 245 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> > new file mode 100644
> > index 000000000000..a6a7e0b05821
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> > @@ -0,0 +1,245 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/clock/reg-clock-controller.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Simple straight-forward register-based clocks
>
> 'simple' means extended one property at a time with little foresight. In
> the end, 'simple' bindings are never simple. s/simple/generic/ as well.
>
> When we first started the clock binding, we had exactly this. There's
> still bindings for at least some of it. It turned out to be a bad
> idea because it was difficult to get correct and complete. So this
> binding is exactly what we don't want.
>
> Rob

Thanks. So in the next version v2, clock-controller are made merely
container of clocks. The real jobs are done by sub clock nodes, so
that clocks, with or without hardware-specific clock types
"compatible", can be declared independently and individually as dt
nodes, instead of hardware clock "controllers" with quite arbitrary
clock identifiers listed under include/dt-bindings/clock/.

2023-04-18 00:20:24

by Stephen Boyd

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Subject: Re: [PATCH 1/2] dt-bindings: clock: Add reg-clock-controller

Quoting Yangfl (2023-04-17 14:39:23)
> Rob Herring <[email protected]> 于2023年4月18日周二 04:49写道:
> >
> > On Sat, Apr 15, 2023 at 02:12:59AM +0800, David Yang wrote:
> > > Add DT bindings documentation for reg-clock-controller, collection of
> > > basic clocks common to many platforms.
> > >
> > > Signed-off-by: David Yang <[email protected]>
> > > ---
> > > .../bindings/clock/reg-clock-controller.yaml | 245 ++++++++++++++++++
> > > 1 file changed, 245 insertions(+)
> > > create mode 100644 Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> > > new file mode 100644
> > > index 000000000000..a6a7e0b05821
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/clock/reg-clock-controller.yaml
> > > @@ -0,0 +1,245 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/clock/reg-clock-controller.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Simple straight-forward register-based clocks
> >
> > 'simple' means extended one property at a time with little foresight. In
> > the end, 'simple' bindings are never simple. s/simple/generic/ as well.
> >
> > When we first started the clock binding, we had exactly this. There's
> > still bindings for at least some of it. It turned out to be a bad
> > idea because it was difficult to get correct and complete. So this
> > binding is exactly what we don't want.
> >
> > Rob
>
> Thanks. So in the next version v2, clock-controller are made merely
> container of clocks. The real jobs are done by sub clock nodes, so
> that clocks, with or without hardware-specific clock types
> "compatible", can be declared independently and individually as dt
> nodes, instead of hardware clock "controllers" with quite arbitrary
> clock identifiers listed under include/dt-bindings/clock/.

No. Write actual drivers and actual bindings for real devices.