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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/clk/clk-gate.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/clk/clk-gate.c')
-rw-r--r--drivers/clk/clk-gate.c259
1 files changed, 259 insertions, 0 deletions
diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c
new file mode 100644
index 000000000..44f5e0c53
--- /dev/null
+++ b/drivers/clk/clk-gate.c
@@ -0,0 +1,259 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
+ * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
+ *
+ * Gated clock implementation
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/string.h>
+
+/**
+ * DOC: basic gateable clock which can gate and ungate its output
+ *
+ * Traits of this clock:
+ * prepare - clk_(un)prepare only ensures parent is (un)prepared
+ * enable - clk_enable and clk_disable are functional & control gating
+ * rate - inherits rate from parent. No clk_set_rate support
+ * parent - fixed parent. No clk_set_parent support
+ */
+
+static inline u32 clk_gate_readl(struct clk_gate *gate)
+{
+ if (gate->flags & CLK_GATE_BIG_ENDIAN)
+ return ioread32be(gate->reg);
+
+ return readl(gate->reg);
+}
+
+static inline void clk_gate_writel(struct clk_gate *gate, u32 val)
+{
+ if (gate->flags & CLK_GATE_BIG_ENDIAN)
+ iowrite32be(val, gate->reg);
+ else
+ writel(val, gate->reg);
+}
+
+/*
+ * It works on following logic:
+ *
+ * For enabling clock, enable = 1
+ * set2dis = 1 -> clear bit -> set = 0
+ * set2dis = 0 -> set bit -> set = 1
+ *
+ * For disabling clock, enable = 0
+ * set2dis = 1 -> set bit -> set = 1
+ * set2dis = 0 -> clear bit -> set = 0
+ *
+ * So, result is always: enable xor set2dis.
+ */
+static void clk_gate_endisable(struct clk_hw *hw, int enable)
+{
+ struct clk_gate *gate = to_clk_gate(hw);
+ int set = gate->flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0;
+ unsigned long flags;
+ u32 reg;
+
+ set ^= enable;
+
+ if (gate->lock)
+ spin_lock_irqsave(gate->lock, flags);
+ else
+ __acquire(gate->lock);
+
+ if (gate->flags & CLK_GATE_HIWORD_MASK) {
+ reg = BIT(gate->bit_idx + 16);
+ if (set)
+ reg |= BIT(gate->bit_idx);
+ } else {
+ reg = clk_gate_readl(gate);
+
+ if (set)
+ reg |= BIT(gate->bit_idx);
+ else
+ reg &= ~BIT(gate->bit_idx);
+ }
+
+ clk_gate_writel(gate, reg);
+
+ if (gate->lock)
+ spin_unlock_irqrestore(gate->lock, flags);
+ else
+ __release(gate->lock);
+}
+
+static int clk_gate_enable(struct clk_hw *hw)
+{
+ clk_gate_endisable(hw, 1);
+
+ return 0;
+}
+
+static void clk_gate_disable(struct clk_hw *hw)
+{
+ clk_gate_endisable(hw, 0);
+}
+
+int clk_gate_is_enabled(struct clk_hw *hw)
+{
+ u32 reg;
+ struct clk_gate *gate = to_clk_gate(hw);
+
+ reg = clk_gate_readl(gate);
+
+ /* if a set bit disables this clk, flip it before masking */
+ if (gate->flags & CLK_GATE_SET_TO_DISABLE)
+ reg ^= BIT(gate->bit_idx);
+
+ reg &= BIT(gate->bit_idx);
+
+ return reg ? 1 : 0;
+}
+EXPORT_SYMBOL_GPL(clk_gate_is_enabled);
+
+const struct clk_ops clk_gate_ops = {
+ .enable = clk_gate_enable,
+ .disable = clk_gate_disable,
+ .is_enabled = clk_gate_is_enabled,
+};
+EXPORT_SYMBOL_GPL(clk_gate_ops);
+
+struct clk_hw *__clk_hw_register_gate(struct device *dev,
+ struct device_node *np, const char *name,
+ const char *parent_name, const struct clk_hw *parent_hw,
+ const struct clk_parent_data *parent_data,
+ unsigned long flags,
+ void __iomem *reg, u8 bit_idx,
+ u8 clk_gate_flags, spinlock_t *lock)
+{
+ struct clk_gate *gate;
+ struct clk_hw *hw;
+ struct clk_init_data init = {};
+ int ret = -EINVAL;
+
+ if (clk_gate_flags & CLK_GATE_HIWORD_MASK) {
+ if (bit_idx > 15) {
+ pr_err("gate bit exceeds LOWORD field\n");
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ /* allocate the gate */
+ gate = kzalloc_obj(*gate);
+ if (!gate)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &clk_gate_ops;
+ init.flags = flags;
+ init.parent_names = parent_name ? &parent_name : NULL;
+ init.parent_hws = parent_hw ? &parent_hw : NULL;
+ init.parent_data = parent_data;
+ if (parent_name || parent_hw || parent_data)
+ init.num_parents = 1;
+ else
+ init.num_parents = 0;
+
+ /* struct clk_gate assignments */
+ gate->reg = reg;
+ gate->bit_idx = bit_idx;
+ gate->flags = clk_gate_flags;
+ gate->lock = lock;
+ gate->hw.init = &init;
+
+ hw = &gate->hw;
+ if (dev || !np)
+ ret = clk_hw_register(dev, hw);
+ else if (np)
+ ret = of_clk_hw_register(np, hw);
+ if (ret) {
+ kfree(gate);
+ hw = ERR_PTR(ret);
+ }
+
+ return hw;
+
+}
+EXPORT_SYMBOL_GPL(__clk_hw_register_gate);
+
+struct clk *clk_register_gate(struct device *dev, const char *name,
+ const char *parent_name, unsigned long flags,
+ void __iomem *reg, u8 bit_idx,
+ u8 clk_gate_flags, spinlock_t *lock)
+{
+ struct clk_hw *hw;
+
+ hw = clk_hw_register_gate(dev, name, parent_name, flags, reg,
+ bit_idx, clk_gate_flags, lock);
+ if (IS_ERR(hw))
+ return ERR_CAST(hw);
+ return hw->clk;
+}
+EXPORT_SYMBOL_GPL(clk_register_gate);
+
+void clk_unregister_gate(struct clk *clk)
+{
+ struct clk_gate *gate;
+ struct clk_hw *hw;
+
+ hw = __clk_get_hw(clk);
+ if (!hw)
+ return;
+
+ gate = to_clk_gate(hw);
+
+ clk_unregister(clk);
+ kfree(gate);
+}
+EXPORT_SYMBOL_GPL(clk_unregister_gate);
+
+void clk_hw_unregister_gate(struct clk_hw *hw)
+{
+ struct clk_gate *gate;
+
+ gate = to_clk_gate(hw);
+
+ clk_hw_unregister(hw);
+ kfree(gate);
+}
+EXPORT_SYMBOL_GPL(clk_hw_unregister_gate);
+
+static void devm_clk_hw_release_gate(struct device *dev, void *res)
+{
+ clk_hw_unregister_gate(*(struct clk_hw **)res);
+}
+
+struct clk_hw *__devm_clk_hw_register_gate(struct device *dev,
+ struct device_node *np, const char *name,
+ const char *parent_name, const struct clk_hw *parent_hw,
+ const struct clk_parent_data *parent_data,
+ unsigned long flags,
+ void __iomem *reg, u8 bit_idx,
+ u8 clk_gate_flags, spinlock_t *lock)
+{
+ struct clk_hw **ptr, *hw;
+
+ ptr = devres_alloc(devm_clk_hw_release_gate, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ hw = __clk_hw_register_gate(dev, np, name, parent_name, parent_hw,
+ parent_data, flags, reg, bit_idx,
+ clk_gate_flags, lock);
+
+ if (!IS_ERR(hw)) {
+ *ptr = hw;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return hw;
+}
+EXPORT_SYMBOL_GPL(__devm_clk_hw_register_gate);