From patchwork Wed Apr 25 15:28:13 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [23/33] ARM i.MX: Add common clock support for 2bit gate From: Sascha Hauer X-Patchwork-Id: 155019 Message-Id: <1335367703-19929-24-git-send-email-s.hauer@pengutronix.de> To: Cc: Sascha Hauer , Shawn Guo Date: Wed, 25 Apr 2012 17:28:13 +0200 This gate consists of two bits: 0b00: clk disabled 0b01: clk enabled in run mode and disabled in sleep mode 0b11: clk enabled Currently only disabled and enabled are supported. As it's unlikely that we find something like this in another SoC create a i.MX specific clk helper for this. Signed-off-by: Sascha Hauer --- arch/arm/mach-imx/Makefile | 2 +- arch/arm/mach-imx/clk-gate2.c | 115 +++++++++++++++++++++++++++++++++++++++++ arch/arm/mach-imx/clk.h | 12 +++++ 3 files changed, 128 insertions(+), 1 deletion(-) create mode 100644 arch/arm/mach-imx/clk-gate2.c diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile index 66bc6be..1b3f2ae 100644 --- a/arch/arm/mach-imx/Makefile +++ b/arch/arm/mach-imx/Makefile @@ -11,7 +11,7 @@ obj-$(CONFIG_SOC_IMX35) += mm-imx3.o cpu-imx35.o clock-imx35.o ehci-imx35.o pm-i obj-$(CONFIG_SOC_IMX5) += cpu-imx5.o mm-imx5.o clock-mx51-mx53.o ehci-imx5.o pm-imx5.o cpu_op-mx51.o -obj-$(CONFIG_COMMON_CLK) += clk-pllv1.o clk-pllv2.o clk-pllv3.o +obj-$(CONFIG_COMMON_CLK) += clk-pllv1.o clk-pllv2.o clk-pllv3.o clk-gate2.o # Support for CMOS sensor interface obj-$(CONFIG_MX1_VIDEO) += mx1-camera-fiq.o mx1-camera-fiq-ksym.o diff --git a/arch/arm/mach-imx/clk-gate2.c b/arch/arm/mach-imx/clk-gate2.c new file mode 100644 index 0000000..3e4713c8 --- /dev/null +++ b/arch/arm/mach-imx/clk-gate2.c @@ -0,0 +1,115 @@ +/* + * Copyright (C) 2010-2011 Canonical Ltd + * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd + * + * 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 +#include +#include +#include +#include +#include + +/** + * 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 + */ + +#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw) + +static int clk_gate2_enable(struct clk_hw *hw) +{ + struct clk_gate *gate = to_clk_gate(hw); + u32 reg; + unsigned long flags = 0; + + if (gate->lock) + spin_lock_irqsave(gate->lock, flags); + + reg = readl(gate->reg); + reg |= 3 << gate->bit_idx; + writel(reg, gate->reg); + + if (gate->lock) + spin_unlock_irqrestore(gate->lock, flags); + + return 0; +} + +static void clk_gate2_disable(struct clk_hw *hw) +{ + struct clk_gate *gate = to_clk_gate(hw); + u32 reg; + unsigned long flags = 0; + + if (gate->lock) + spin_lock_irqsave(gate->lock, flags); + + reg = readl(gate->reg); + reg &= ~(3 << gate->bit_idx); + writel(reg, gate->reg); + + if (gate->lock) + spin_unlock_irqrestore(gate->lock, flags); +} + +static int clk_gate2_is_enabled(struct clk_hw *hw) +{ + u32 reg; + struct clk_gate *gate = to_clk_gate(hw); + + reg = readl(gate->reg); + + if (((reg >> gate->bit_idx) & 3) == 3) + return 1; + + return 0; +} + +static struct clk_ops clk_gate2_ops = { + .enable = clk_gate2_enable, + .disable = clk_gate2_disable, + .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) +{ + struct clk_gate *gate; + struct clk *clk; + + gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL); + if (!gate) { + pr_err("%s: could not allocate gated clk\n", __func__); + return ERR_PTR(-ENOMEM); + } + + /* struct clk_gate assignments */ + gate->reg = reg; + gate->bit_idx = bit_idx; + gate->flags = clk_gate2_flags; + gate->lock = lock; + + clk = clk_register(dev, name, + &clk_gate2_ops, &gate->hw, + (parent_name ? &parent_name : NULL), + (parent_name ? 1 : 0), + flags); + if (IS_ERR(clk)) + kfree(clk); + + return clk; +} diff --git a/arch/arm/mach-imx/clk.h b/arch/arm/mach-imx/clk.h index 331316d..5f6e435 100644 --- a/arch/arm/mach-imx/clk.h +++ b/arch/arm/mach-imx/clk.h @@ -24,6 +24,18 @@ struct clk *imx_clk_pllv3(enum imx_pllv3_type type, const char *name, const char *parent_name, void __iomem *base, u32 gate_mask, u32 div_mask); +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_gate_flags, spinlock_t *lock); + +static inline struct clk *imx_clk_gate2(const char *name, const char *parent, + void __iomem *reg, u8 shift) +{ + return clk_register_gate2(NULL, name, parent, CLK_SET_RATE_PARENT, reg, + shift, 0, &imx_ccm_lock); +} + static inline struct clk *imx_clk_fixed(const char *name, int rate) { return clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);