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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/clk/clk-gate.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
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);