[PATCH V2 2/6] SPEAr: clk: Add Auxiliary Synthesizer clock
Viresh Kumar
viresh.linux at gmail.com
Thu Apr 19 12:28:17 EDT 2012
All SPEAr SoC's contain Auxiliary Synthesizers. Their Fout is derived based on
values of eq, x and y.
Fout from synthesizer can be given from two equations:
Fout1 = (Fin * X/Y)/2 EQ1
Fout2 = Fin * X/Y EQ2
This patch adds in support for this type of clock.
Signed-off-by: Viresh Kumar <viresh.kumar at st.com>
---
drivers/clk/spear/Makefile | 2 +-
drivers/clk/spear/clk-aux-synth.c | 187 +++++++++++++++++++++++++++++++++++++
drivers/clk/spear/clk.h | 43 +++++++++
3 files changed, 231 insertions(+), 1 deletions(-)
create mode 100644 drivers/clk/spear/clk-aux-synth.c
diff --git a/drivers/clk/spear/Makefile b/drivers/clk/spear/Makefile
index f59469f..407a8e0 100644
--- a/drivers/clk/spear/Makefile
+++ b/drivers/clk/spear/Makefile
@@ -2,4 +2,4 @@
# SPEAr Clock specific Makefile
#
-obj-y += clk-vco-pll.o
+obj-y += clk-aux-synth.o clk-vco-pll.o
diff --git a/drivers/clk/spear/clk-aux-synth.c b/drivers/clk/spear/clk-aux-synth.c
new file mode 100644
index 0000000..1a7ab7d
--- /dev/null
+++ b/drivers/clk/spear/clk-aux-synth.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 2012 ST Microelectronics
+ * Viresh Kumar <viresh.kumar at st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * Auxiliary Synthesizer clock implementation
+ */
+
+#define pr_fmt(fmt) "clk-aux-synth: " fmt
+
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include "clk.h"
+
+/*
+ * DOC: Auxiliary Synthesizer clock
+ *
+ * Aux synth gives rate for different values of eq, x and y
+ *
+ * Fout from synthesizer can be given from two equations:
+ * Fout1 = (Fin * X/Y)/2 EQ1
+ * Fout2 = Fin * X/Y EQ2
+ */
+
+#define to_clk_aux(_hw) container_of(_hw, struct clk_aux, hw)
+
+static struct aux_clk_masks default_aux_masks = {
+ .eq_sel_mask = AUX_EQ_SEL_MASK,
+ .eq_sel_shift = AUX_EQ_SEL_SHIFT,
+ .eq1_mask = AUX_EQ1_SEL,
+ .eq2_mask = AUX_EQ2_SEL,
+ .xscale_sel_mask = AUX_XSCALE_MASK,
+ .xscale_sel_shift = AUX_XSCALE_SHIFT,
+ .yscale_sel_mask = AUX_YSCALE_MASK,
+ .yscale_sel_shift = AUX_YSCALE_SHIFT,
+ .enable_bit = AUX_SYNT_ENB,
+};
+
+static unsigned long aux_calc_rate(struct clk_hw *hw, unsigned long prate,
+ int index)
+{
+ struct clk_aux *aux = to_clk_aux(hw);
+ struct aux_rate_tbl *rtbl = aux->rtbl;
+ u8 eq = rtbl[index].eq ? 1 : 2;
+
+ return (((prate / 10000) * rtbl[index].xscale) /
+ (rtbl[index].yscale * eq)) * 10000;
+}
+
+static long clk_aux_round_rate(struct clk_hw *hw, unsigned long drate,
+ unsigned long *prate)
+{
+ struct clk_aux *aux = to_clk_aux(hw);
+ int unused;
+
+ return clk_round_rate_index(hw, drate, aux_calc_rate, aux->rtbl_cnt,
+ &unused);
+}
+
+static unsigned long clk_aux_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_aux *aux = to_clk_aux(hw);
+ unsigned int num = 1, den = 1, val, eqn;
+ unsigned long flags = 0;
+
+ if (aux->lock)
+ spin_lock_irqsave(aux->lock, flags);
+
+ val = readl_relaxed(aux->reg);
+
+ if (aux->lock)
+ spin_unlock_irqrestore(aux->lock, flags);
+
+ eqn = (val >> aux->masks->eq_sel_shift) & aux->masks->eq_sel_mask;
+ if (eqn == aux->masks->eq1_mask)
+ den = 2;
+
+ /* calculate numerator */
+ num = (val >> aux->masks->xscale_sel_shift) &
+ aux->masks->xscale_sel_mask;
+
+ /* calculate denominator */
+ den *= (val >> aux->masks->yscale_sel_shift) &
+ aux->masks->yscale_sel_mask;
+
+ if (!den)
+ return 0;
+
+ return (((parent_rate / 10000) * num) / den) * 10000;
+}
+
+/* Configures new clock rate of aux */
+static int clk_aux_set_rate(struct clk_hw *hw, unsigned long drate)
+{
+ struct clk_aux *aux = to_clk_aux(hw);
+ struct aux_rate_tbl *rtbl = aux->rtbl;
+ unsigned long val, flags = 0;
+ int i;
+
+ clk_round_rate_index(hw, drate, aux_calc_rate, aux->rtbl_cnt, &i);
+
+ if (aux->lock)
+ spin_lock_irqsave(aux->lock, flags);
+
+ val = readl_relaxed(aux->reg) &
+ ~(aux->masks->eq_sel_mask << aux->masks->eq_sel_shift);
+ val |= (rtbl[i].eq & aux->masks->eq_sel_mask) <<
+ aux->masks->eq_sel_shift;
+ val &= ~(aux->masks->xscale_sel_mask << aux->masks->xscale_sel_shift);
+ val |= (rtbl[i].xscale & aux->masks->xscale_sel_mask) <<
+ aux->masks->xscale_sel_shift;
+ val &= ~(aux->masks->yscale_sel_mask << aux->masks->yscale_sel_shift);
+ val |= (rtbl[i].yscale & aux->masks->yscale_sel_mask) <<
+ aux->masks->yscale_sel_shift;
+ writel_relaxed(val, aux->reg);
+
+ if (aux->lock)
+ spin_unlock_irqrestore(aux->lock, flags);
+
+ return 0;
+}
+
+static struct clk_ops clk_aux_ops = {
+ .recalc_rate = clk_aux_recalc_rate,
+ .round_rate = clk_aux_round_rate,
+ .set_rate = clk_aux_set_rate,
+};
+
+struct clk *clk_register_aux(const char *aux_name, const char *gate_name,
+ const char *parent_name, unsigned long flags, void __iomem *reg,
+ struct aux_clk_masks *masks, struct aux_rate_tbl *rtbl,
+ u8 rtbl_cnt, spinlock_t *lock, struct clk **gate_clk)
+{
+ struct clk_aux *aux;
+ struct clk *clk;
+
+ if (!aux_name || !parent_name || !reg || !rtbl || !rtbl_cnt) {
+ pr_err("Invalid arguments passed");
+ return ERR_PTR(-EINVAL);
+ }
+
+ aux = kzalloc(sizeof(*aux), GFP_KERNEL);
+ if (!aux) {
+ pr_err("could not allocate aux clk\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ /* struct clk_aux assignments */
+ if (!masks)
+ aux->masks = &default_aux_masks;
+
+ aux->reg = reg;
+ aux->rtbl = rtbl;
+ aux->rtbl_cnt = rtbl_cnt;
+ aux->lock = lock;
+
+ clk = clk_register(NULL, aux_name, &clk_aux_ops, &aux->hw, &parent_name,
+ 1, flags);
+ if (IS_ERR_OR_NULL(clk))
+ goto free_aux;
+
+ if (gate_name) {
+ struct clk *tgate_clk;
+
+ tgate_clk = clk_register_gate(NULL, gate_name, aux_name, 0, reg,
+ aux->masks->enable_bit, 0, lock);
+ if (IS_ERR_OR_NULL(tgate_clk))
+ goto free_aux;
+
+ if (gate_clk)
+ *gate_clk = tgate_clk;
+ }
+
+ return clk;
+
+free_aux:
+ kfree(aux);
+ pr_err("clk register failed\n");
+
+ return NULL;
+}
diff --git a/drivers/clk/spear/clk.h b/drivers/clk/spear/clk.h
index a66024e..5e279ee 100644
--- a/drivers/clk/spear/clk.h
+++ b/drivers/clk/spear/clk.h
@@ -16,6 +16,45 @@
#include <linux/spinlock_types.h>
#include <linux/types.h>
+/* Auxiliary Synth clk */
+/* Default masks */
+#define AUX_EQ_SEL_SHIFT 30
+#define AUX_EQ_SEL_MASK 1
+#define AUX_EQ1_SEL 0
+#define AUX_EQ2_SEL 1
+#define AUX_XSCALE_SHIFT 16
+#define AUX_XSCALE_MASK 0xFFF
+#define AUX_YSCALE_SHIFT 0
+#define AUX_YSCALE_MASK 0xFFF
+#define AUX_SYNT_ENB 31
+
+struct aux_clk_masks {
+ u32 eq_sel_mask;
+ u32 eq_sel_shift;
+ u32 eq1_mask;
+ u32 eq2_mask;
+ u32 xscale_sel_mask;
+ u32 xscale_sel_shift;
+ u32 yscale_sel_mask;
+ u32 yscale_sel_shift;
+ u32 enable_bit;
+};
+
+struct aux_rate_tbl {
+ u16 xscale;
+ u16 yscale;
+ u8 eq;
+};
+
+struct clk_aux {
+ struct clk_hw hw;
+ void __iomem *reg;
+ struct aux_clk_masks *masks;
+ struct aux_rate_tbl *rtbl;
+ u8 rtbl_cnt;
+ spinlock_t *lock;
+};
+
/* VCO-PLL clk */
struct pll_rate_tbl {
u8 mode;
@@ -44,6 +83,10 @@ typedef unsigned long (*clk_calc_rate)(struct clk_hw *hw, unsigned long prate,
int index);
/* clk register routines */
+struct clk *clk_register_aux(const char *aux_name, const char *gate_name,
+ const char *parent_name, unsigned long flags, void __iomem *reg,
+ struct aux_clk_masks *masks, struct aux_rate_tbl *rtbl,
+ u8 rtbl_cnt, spinlock_t *lock, struct clk **gate_clk);
struct clk *clk_register_vco_pll(const char *vco_name, const char *pll_name,
const char *vco_gate_name, const char *parent_name,
unsigned long flags, void __iomem *mode_reg, void __iomem
--
1.7.9
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