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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-26 20:34:35 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-26 20:34:35 +0200 |
commit | 4aa705b18bf17c4ff33ff7bbcd3f0c596443fa81 (patch) | |
tree | 3b166bff290d123ccaa88598ad2d45be67f5b358 /drivers/clk/imx/clk-gate2.c | |
parent | Merge tag 'armsoc-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/a... (diff) | |
parent | Merge tag 'omap-for-v4.2/soc-pt1-take2' of git://git.kernel.org/pub/scm/linux... (diff) | |
download | linux-4aa705b18bf17c4ff33ff7bbcd3f0c596443fa81.tar.xz linux-4aa705b18bf17c4ff33ff7bbcd3f0c596443fa81.zip |
Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC platform support updates from Kevin Hilman:
"Our SoC branch usually contains expanded support for new SoCs and
other core platform code. Some highlights from this round:
- sunxi: SMP support for A23 SoC
- socpga: big-endian support
- pxa: conversion to common clock framework
- bcm: SMP support for BCM63138
- imx: support new I.MX7D SoC
- zte: basic support for ZX296702 SoC"
* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (134 commits)
ARM: zx: Add basic defconfig support for ZX296702
ARM: dts: zx: add an initial zx296702 dts and doc
clk: zx: add clock support to zx296702
dt-bindings: Add #defines for ZTE ZX296702 clocks
ARM: socfpga: fix build error due to secondary_startup
MAINTAINERS: ARM64: EXYNOS: Extend entry for ARM64 DTS
ARM: ep93xx: simone: support for SPI-based MMC/SD cards
MAINTAINERS: update Shawn's email to use kernel.org one
ARM: socfpga: support suspend to ram
ARM: socfpga: add CPU_METHOD_OF_DECLARE for Arria 10
ARM: socfpga: use CPU_METHOD_OF_DECLARE for socfpga_cyclone5
ARM: EXYNOS: register power domain driver from core_initcall
ARM: EXYNOS: use PS_HOLD based poweroff for all supported SoCs
ARM: SAMSUNG: Constify platform_device_id
ARM: EXYNOS: Constify irq_domain_ops
ARM: EXYNOS: add coupled cpuidle support for Exynos3250
ARM: EXYNOS: add exynos_get_boot_addr() helper
ARM: EXYNOS: add exynos_set_boot_addr() helper
ARM: EXYNOS: make exynos_core_restart() less verbose
ARM: EXYNOS: fix exynos_boot_secondary() return value on timeout
...
Diffstat (limited to 'drivers/clk/imx/clk-gate2.c')
-rw-r--r-- | drivers/clk/imx/clk-gate2.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-gate2.c b/drivers/clk/imx/clk-gate2.c new file mode 100644 index 000000000000..8935bff99fe7 --- /dev/null +++ b/drivers/clk/imx/clk-gate2.c @@ -0,0 +1,160 @@ +/* + * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com> + * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Gated clock implementation + */ + +#include <linux/clk-provider.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/err.h> +#include <linux/string.h> +#include "clk.h" + +/** + * DOC: basic gatable clock which can gate and ungate it's ouput + * + * 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 + */ + +struct clk_gate2 { + struct clk_hw hw; + void __iomem *reg; + u8 bit_idx; + u8 flags; + spinlock_t *lock; + unsigned int *share_count; +}; + +#define to_clk_gate2(_hw) container_of(_hw, struct clk_gate2, hw) + +static int clk_gate2_enable(struct clk_hw *hw) +{ + struct clk_gate2 *gate = to_clk_gate2(hw); + u32 reg; + unsigned long flags = 0; + + spin_lock_irqsave(gate->lock, flags); + + if (gate->share_count && (*gate->share_count)++ > 0) + goto out; + + reg = readl(gate->reg); + reg |= 3 << gate->bit_idx; + writel(reg, gate->reg); + +out: + spin_unlock_irqrestore(gate->lock, flags); + + return 0; +} + +static void clk_gate2_disable(struct clk_hw *hw) +{ + struct clk_gate2 *gate = to_clk_gate2(hw); + u32 reg; + unsigned long flags = 0; + + spin_lock_irqsave(gate->lock, flags); + + if (gate->share_count) { + if (WARN_ON(*gate->share_count == 0)) + goto out; + else if (--(*gate->share_count) > 0) + goto out; + } + + reg = readl(gate->reg); + reg &= ~(3 << gate->bit_idx); + writel(reg, gate->reg); + +out: + spin_unlock_irqrestore(gate->lock, flags); +} + +static int clk_gate2_reg_is_enabled(void __iomem *reg, u8 bit_idx) +{ + u32 val = readl(reg); + + if (((val >> bit_idx) & 1) == 1) + return 1; + + return 0; +} + +static int clk_gate2_is_enabled(struct clk_hw *hw) +{ + struct clk_gate2 *gate = to_clk_gate2(hw); + + return clk_gate2_reg_is_enabled(gate->reg, gate->bit_idx); +} + +static void clk_gate2_disable_unused(struct clk_hw *hw) +{ + struct clk_gate2 *gate = to_clk_gate2(hw); + unsigned long flags = 0; + u32 reg; + + spin_lock_irqsave(gate->lock, flags); + + if (!gate->share_count || *gate->share_count == 0) { + reg = readl(gate->reg); + reg &= ~(3 << gate->bit_idx); + writel(reg, gate->reg); + } + + spin_unlock_irqrestore(gate->lock, flags); +} + +static struct clk_ops clk_gate2_ops = { + .enable = clk_gate2_enable, + .disable = clk_gate2_disable, + .disable_unused = clk_gate2_disable_unused, + .is_enabled = clk_gate2_is_enabled, +}; + +struct clk *clk_register_gate2(struct device *dev, const char *name, + const char *parent_name, unsigned long flags, + void __iomem *reg, u8 bit_idx, + u8 clk_gate2_flags, spinlock_t *lock, + unsigned int *share_count) +{ + struct clk_gate2 *gate; + struct clk *clk; + struct clk_init_data init; + + gate = kzalloc(sizeof(struct clk_gate2), GFP_KERNEL); + if (!gate) + return ERR_PTR(-ENOMEM); + + /* struct clk_gate2 assignments */ + gate->reg = reg; + gate->bit_idx = bit_idx; + gate->flags = clk_gate2_flags; + gate->lock = lock; + gate->share_count = share_count; + + init.name = name; + init.ops = &clk_gate2_ops; + init.flags = flags; + init.parent_names = parent_name ? &parent_name : NULL; + init.num_parents = parent_name ? 1 : 0; + + gate->hw.init = &init; + + clk = clk_register(dev, &gate->hw); + if (IS_ERR(clk)) + kfree(gate); + + return clk; +} |