[PATCH 1/8] clk: mxs: add mxs specific clocks
Shawn Guo
shawn.guo at linaro.org
Sat Apr 21 11:57:13 EDT 2012
Add mxs specific clocks, pll, reference clock (PFD), integer divider
and fractional divider.
Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
---
drivers/clk/mxs/Makefile | 5 ++
drivers/clk/mxs/clk-div.c | 102 ++++++++++++++++++++++++++++++++
drivers/clk/mxs/clk-frac.c | 127 ++++++++++++++++++++++++++++++++++++++++
drivers/clk/mxs/clk-pll.c | 123 +++++++++++++++++++++++++++++++++++++++
drivers/clk/mxs/clk-ref.c | 139 ++++++++++++++++++++++++++++++++++++++++++++
drivers/clk/mxs/clk.h | 75 ++++++++++++++++++++++++
6 files changed, 571 insertions(+), 0 deletions(-)
create mode 100644 drivers/clk/mxs/Makefile
create mode 100644 drivers/clk/mxs/clk-div.c
create mode 100644 drivers/clk/mxs/clk-frac.c
create mode 100644 drivers/clk/mxs/clk-pll.c
create mode 100644 drivers/clk/mxs/clk-ref.c
create mode 100644 drivers/clk/mxs/clk.h
diff --git a/drivers/clk/mxs/Makefile b/drivers/clk/mxs/Makefile
new file mode 100644
index 0000000..067c231
--- /dev/null
+++ b/drivers/clk/mxs/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for mxs specific clk
+#
+
+obj-y += clk-pll.o clk-ref.o clk-div.o clk-frac.o
diff --git a/drivers/clk/mxs/clk-div.c b/drivers/clk/mxs/clk-div.c
new file mode 100644
index 0000000..679a927
--- /dev/null
+++ b/drivers/clk/mxs/clk-div.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include "clk.h"
+
+/**
+ * struct clk_div - mxs integer divider clock
+ * @divider: the parent class
+ * @ops: pointer to clk_ops of parent class
+ * @reg: register address
+ * @busy: busy bit shift
+ *
+ * The mxs divider clock is a subclass of basic clk_divider with an
+ * addtional busy bit.
+ */
+struct clk_div {
+ struct clk_divider divider;
+ const struct clk_ops *ops;
+ void __iomem *reg;
+ u8 busy;
+};
+
+static inline struct clk_div *to_clk_div(struct clk_hw *hw)
+{
+ struct clk_divider *divider = container_of(hw, struct clk_divider, hw);
+
+ return container_of(divider, struct clk_div, divider);
+}
+
+static unsigned long clk_div_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_div *div = to_clk_div(hw);
+
+ return div->ops->recalc_rate(&div->divider.hw, parent_rate);
+}
+
+static long clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct clk_div *div = to_clk_div(hw);
+
+ return div->ops->round_rate(&div->divider.hw, rate, prate);
+}
+
+static int clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_div *div = to_clk_div(hw);
+ int ret;
+
+ ret = div->ops->set_rate(&div->divider.hw, rate, parent_rate);
+ if (!ret)
+ ret = mxs_clk_wait(div->reg, div->busy);
+
+ return ret;
+}
+
+static struct clk_ops clk_div_ops = {
+ .recalc_rate = clk_div_recalc_rate,
+ .round_rate = clk_div_round_rate,
+ .set_rate = clk_div_set_rate,
+};
+
+struct clk *mxs_clk_div(const char *name, const char *parent_name,
+ void __iomem *reg, u8 shift, u8 width, u8 busy)
+{
+ struct clk_div *div;
+ struct clk *clk;
+
+ div = kzalloc(sizeof(*div), GFP_KERNEL);
+ if (!div)
+ return ERR_PTR(-ENOMEM);
+
+ div->reg = reg;
+ div->busy = busy;
+
+ div->divider.reg = reg;
+ div->divider.shift = shift;
+ div->divider.width = width;
+ div->divider.flags = CLK_DIVIDER_ONE_BASED;
+ div->ops = &clk_divider_ops;
+
+ clk = clk_register(NULL, name, &clk_div_ops, &div->divider.hw,
+ &parent_name, 1, CLK_SET_RATE_PARENT);
+ if (!clk)
+ kfree(div);
+
+ return clk;
+}
diff --git a/drivers/clk/mxs/clk-frac.c b/drivers/clk/mxs/clk-frac.c
new file mode 100644
index 0000000..9acf1fc
--- /dev/null
+++ b/drivers/clk/mxs/clk-frac.c
@@ -0,0 +1,127 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include "clk.h"
+
+/**
+ * struct clk_frac - mxs fractional divider clock
+ * @hw: clk_hw for the fractional divider clock
+ * @reg: register address
+ * @shift: the divider bit shift
+ * @width: the divider bit width
+ * @busy: busy bit shift
+ *
+ * The clock is an adjustable fractional divider with a busy bit to wait
+ * when the divider is adjusted.
+ */
+struct clk_frac {
+ struct clk_hw hw;
+ void __iomem *reg;
+ u8 shift;
+ u8 width;
+ u8 busy;
+};
+
+#define to_clk_frac(_hw) container_of(_hw, struct clk_frac, hw)
+
+static unsigned long clk_frac_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_frac *frac = to_clk_frac(hw);
+ u32 div;
+
+ div = readl_relaxed(frac->reg) >> frac->shift;
+ div &= (1 << frac->width) - 1;
+
+ return (parent_rate >> frac->width) * div;
+}
+
+static long clk_frac_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct clk_frac *frac = to_clk_frac(hw);
+ unsigned long parent_rate = *prate;
+ u32 div;
+ u64 tmp;
+
+ if (rate > parent_rate)
+ return -EINVAL;
+
+ tmp = rate;
+ tmp <<= frac->width;
+ do_div(tmp, parent_rate);
+ div = tmp;
+
+ if (!div)
+ return -EINVAL;
+
+ return (parent_rate >> frac->width) * div;
+}
+
+static int clk_frac_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_frac *frac = to_clk_frac(hw);
+ u32 div, val;
+ u64 tmp;
+
+ if (rate > parent_rate)
+ return -EINVAL;
+
+ tmp = rate;
+ tmp <<= frac->width;
+ do_div(tmp, parent_rate);
+ div = tmp;
+
+ if (!div)
+ return -EINVAL;
+
+ val = readl_relaxed(frac->reg);
+ val &= ~(((1 << frac->width) - 1) << frac->shift);
+ val |= div << frac->shift;
+ writel_relaxed(val, frac->reg);
+
+ return mxs_clk_wait(frac->reg, frac->busy);
+}
+
+static struct clk_ops clk_frac_ops = {
+ .recalc_rate = clk_frac_recalc_rate,
+ .round_rate = clk_frac_round_rate,
+ .set_rate = clk_frac_set_rate,
+};
+
+struct clk *mxs_clk_frac(const char *name, const char *parent_name,
+ void __iomem *reg, u8 shift, u8 width, u8 busy)
+{
+ struct clk_frac *frac;
+ struct clk *clk;
+
+ frac = kzalloc(sizeof(*frac), GFP_KERNEL);
+ if (!frac)
+ return ERR_PTR(-ENOMEM);
+
+ frac->reg = reg;
+ frac->shift = shift;
+ frac->width = width;
+ frac->busy = busy;
+
+ clk = clk_register(NULL, name, &clk_frac_ops, &frac->hw,
+ &parent_name, 1, CLK_SET_RATE_PARENT);
+ if (!clk)
+ kfree(frac);
+
+ return clk;
+}
diff --git a/drivers/clk/mxs/clk-pll.c b/drivers/clk/mxs/clk-pll.c
new file mode 100644
index 0000000..bde928d
--- /dev/null
+++ b/drivers/clk/mxs/clk-pll.c
@@ -0,0 +1,123 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include "clk.h"
+
+/**
+ * struct clk_pll - mxs pll clock
+ * @hw: clk_hw for the pll
+ * @base: base address of the pll
+ * @power_shift: the shift of power control bit
+ * @gate_shift: the shift of gate control bit
+ * @rate: the clock rate of the pll
+ * @flags: the pll specific flags
+ * PLL_SET_GATE_DISABLE - By default, pll sets gate bit to enable clock.
+ * Settting this flag will have pll set gate bit to disable clock.
+ *
+ * The mxs pll is a fixed rate clock with power and gate control.
+ */
+struct clk_pll {
+ struct clk_hw hw;
+ void __iomem *base;
+ u8 power_shift;
+ u8 gate_shift;
+ unsigned long rate;
+ unsigned long flags;
+};
+
+#define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)
+
+static int clk_pll_prepare(struct clk_hw *hw)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+
+ writel_relaxed(1 << pll->power_shift, pll->base + SET);
+
+ udelay(10);
+
+ return 0;
+}
+
+static void clk_pll_unprepare(struct clk_hw *hw)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+
+ writel_relaxed(1 << pll->power_shift, pll->base + CLR);
+}
+
+static int clk_pll_enable(struct clk_hw *hw)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+
+ if (pll->flags & PLL_SET_GATE_DISABLE)
+ writel_relaxed(1 << pll->gate_shift, pll->base + CLR);
+ else
+ writel_relaxed(1 << pll->gate_shift, pll->base + SET);
+
+ return 0;
+}
+
+static void clk_pll_disable(struct clk_hw *hw)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+
+ if (pll->flags & PLL_SET_GATE_DISABLE)
+ writel_relaxed(1 << pll->gate_shift, pll->base + SET);
+ else
+ writel_relaxed(1 << pll->gate_shift, pll->base + CLR);
+}
+
+static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+
+ return pll->rate;
+}
+
+static const struct clk_ops clk_pll_ops = {
+ .prepare = clk_pll_prepare,
+ .unprepare = clk_pll_unprepare,
+ .enable = clk_pll_enable,
+ .disable = clk_pll_disable,
+ .recalc_rate = clk_pll_recalc_rate,
+};
+
+struct clk *mxs_clk_pll(const char *name, const char *parent_name,
+ void __iomem *base, u8 power_shift, u8 gate_shift,
+ unsigned long rate, unsigned long flags)
+{
+ struct clk_pll *pll;
+ struct clk *clk;
+
+ pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+ if (!pll)
+ return ERR_PTR(-ENOMEM);
+
+ pll->base = base;
+ pll->rate = rate;
+ pll->power_shift = power_shift;
+ pll->gate_shift = gate_shift;
+ pll->flags = flags;
+
+ clk = clk_register(NULL, name, &clk_pll_ops, &pll->hw,
+ &parent_name, 1, 0);
+ if (!clk)
+ kfree(pll);
+
+ return clk;
+}
diff --git a/drivers/clk/mxs/clk-ref.c b/drivers/clk/mxs/clk-ref.c
new file mode 100644
index 0000000..bb2027a
--- /dev/null
+++ b/drivers/clk/mxs/clk-ref.c
@@ -0,0 +1,139 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include "clk.h"
+
+/**
+ * struct clk_ref - mxs reference clock
+ * @hw: clk_hw for the reference clock
+ * @reg: register address
+ * @idx: the index of the reference clock within the same register
+ *
+ * The mxs reference clock sources from pll. Every 4 reference clocks share
+ * one register space, and @idx is used to identify them. Each reference
+ * clock has a gate control and a fractional * divider. The rate is calculated
+ * as pll rate * (18 / FRAC), where FRAC = 18 ~ 35.
+ */
+struct clk_ref {
+ struct clk_hw hw;
+ void __iomem *reg;
+ u8 idx;
+};
+
+#define to_clk_ref(_hw) container_of(_hw, struct clk_ref, hw)
+
+static int clk_ref_enable(struct clk_hw *hw)
+{
+ struct clk_ref *ref = to_clk_ref(hw);
+
+ writel_relaxed(1 << ((ref->idx + 1) * 8 - 1), ref->reg + CLR);
+
+ return 0;
+}
+
+static void clk_ref_disable(struct clk_hw *hw)
+{
+ struct clk_ref *ref = to_clk_ref(hw);
+
+ writel_relaxed(1 << ((ref->idx + 1) * 8 - 1), ref->reg + SET);
+}
+
+static unsigned long clk_ref_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_ref *ref = to_clk_ref(hw);
+ u64 tmp = parent_rate;
+ u8 frac = (readl_relaxed(ref->reg) >> (ref->idx * 8)) & 0x3f;
+
+ tmp *= 18;
+ do_div(tmp, frac);
+
+ return tmp;
+}
+
+static long clk_ref_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ unsigned long parent_rate = *prate;
+ u64 tmp = parent_rate;
+ u8 frac;
+
+ tmp = tmp * 18 + rate / 2;
+ do_div(tmp, rate);
+ frac = tmp;
+
+ if (frac < 18)
+ frac = 18;
+ else if (frac > 35)
+ frac = 35;
+
+ tmp = parent_rate;
+ tmp *= 18;
+ do_div(tmp, frac);
+
+ return tmp;
+}
+
+static int clk_ref_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_ref *ref = to_clk_ref(hw);
+ u64 tmp = parent_rate;
+ u8 frac;
+
+ tmp = tmp * 18 + rate / 2;
+ do_div(tmp, rate);
+ frac = tmp;
+
+ if (frac < 18)
+ frac = 18;
+ else if (frac > 35)
+ frac = 35;
+
+ writel_relaxed(0x3f << (ref->idx * 8), ref->reg + CLR);
+ writel_relaxed(frac << (ref->idx * 8), ref->reg + SET);
+
+ return 0;
+}
+
+static const struct clk_ops clk_ref_ops = {
+ .enable = clk_ref_enable,
+ .disable = clk_ref_disable,
+ .recalc_rate = clk_ref_recalc_rate,
+ .round_rate = clk_ref_round_rate,
+ .set_rate = clk_ref_set_rate,
+};
+
+struct clk *mxs_clk_ref(const char *name, const char *parent_name,
+ void __iomem *reg, u8 idx)
+{
+ struct clk_ref *ref;
+ struct clk *clk;
+
+ ref = kzalloc(sizeof(*ref), GFP_KERNEL);
+ if (!ref)
+ return ERR_PTR(-ENOMEM);
+
+ ref->reg = reg;
+ ref->idx = idx;
+
+ clk = clk_register(NULL, name, &clk_ref_ops, &ref->hw,
+ &parent_name, 1, 0);
+ if (!clk)
+ kfree(ref);
+
+ return clk;
+}
diff --git a/drivers/clk/mxs/clk.h b/drivers/clk/mxs/clk.h
new file mode 100644
index 0000000..deb5c23
--- /dev/null
+++ b/drivers/clk/mxs/clk.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#ifndef __MXS_CLK_H
+#define __MXS_CLK_H
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#define SET 0x4
+#define CLR 0x8
+
+#define PLL_SET_GATE_DISABLE BIT(0)
+
+struct clk *mxs_clk_pll(const char *name, const char *parent_name,
+ void __iomem *base, u8 power_shift, u8 gate_shift,
+ unsigned long rate, unsigned long flags);
+
+struct clk *mxs_clk_ref(const char *name, const char *parent_name,
+ void __iomem *reg, u8 idx);
+
+struct clk *mxs_clk_div(const char *name, const char *parent_name,
+ void __iomem *reg, u8 shift, u8 width, u8 busy);
+
+struct clk *mxs_clk_frac(const char *name, const char *parent_name,
+ void __iomem *reg, u8 shift, u8 width, u8 busy);
+
+static inline struct clk *mxs_clk_fixed(const char *name, int rate)
+{
+ return clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);
+}
+
+static inline struct clk *mxs_clk_gate(const char *name,
+ const char *parent_name, void __iomem *reg, u8 shift)
+{
+ return clk_register_gate(NULL, name, parent_name, CLK_SET_RATE_PARENT,
+ reg, shift, CLK_GATE_SET_TO_DISABLE, NULL);
+}
+
+static inline struct clk *mxs_clk_mux(const char *name, void __iomem *reg,
+ u8 shift, u8 width, const char **parent_names, int num_parents)
+{
+ return clk_register_mux(NULL, name, parent_names, num_parents,
+ CLK_SET_RATE_PARENT, reg, shift, width,
+ 0, NULL);
+}
+
+static inline struct clk *mxs_clk_fixed_factor(const char *name,
+ const char *parent_name, unsigned int mult, unsigned int div)
+{
+ return clk_register_fixed_factor(NULL, name, parent_name,
+ CLK_SET_RATE_PARENT, mult, div);
+}
+
+static inline int mxs_clk_wait(void __iomem *reg, u8 shift)
+{
+ unsigned long timeout = jiffies + msecs_to_jiffies(10);
+
+ while (readl_relaxed(reg) & (1 << shift))
+ if (time_after(jiffies, timeout))
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+#endif /* __MXS_CLK_H */
--
1.7.5.4
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