Add a clock driver for clock deleters in the TZ1090 SoC, which delete up
to 1023 out of every 1024 clock pulses. There are 4 of these in TZ1090,
for the system clock, the Meta core clock, and one for each UCC.
The tz1090_clk_register_deleters() helper function can be used to
register a set of deleters from static initialisation data. A DEL()
macro is provided in tz1090/clk.h to aid the creation of this data, for
example:
static const struct tz1090_clk_deleter deleters[] __initconst = {
DEL(CLK_TOP_SYS, "sys_undeleted", "sys", TOP_CLKDELETE),
...
};
...
tz1090_clk_register_deleters(p, deleters, ARRAY_SIZE(deleters));
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Mike Turquette <mturquette@xxxxxxxxxx>
Cc: linux-metag@xxxxxxxxxxxxxxx
---
Changes since v1 (patch 10):
- Renamed function prefixes from clk_tz1090_ to tz1090_clk_ for
consistency with the rest.
- Drop DT binding as it will be instantiated directly from a provider.
- Add tz1090_clk_register_deleters() to conveniently register a set of
deleters in a clock provider from static initilisation data.
- Extend tz1090/clk.h interface for easy static initialisation with
macros.
---
drivers/clk/tz1090/Makefile | 1 +
drivers/clk/tz1090/clk-tz1090-deleter.c | 132 ++++++++++++++++++++++++++++++++
drivers/clk/tz1090/clk.h | 31 ++++++++
3 files changed, 164 insertions(+)
create mode 100644 drivers/clk/tz1090/clk-tz1090-deleter.c
diff --git a/drivers/clk/tz1090/Makefile b/drivers/clk/tz1090/Makefile
index d44acac..39c29ac 100644
--- a/drivers/clk/tz1090/Makefile
+++ b/drivers/clk/tz1090/Makefile
@@ -1,5 +1,6 @@
# Makefile for TZ1090-specific clocks
obj-y += clk.o
+obj-y += clk-tz1090-deleter.o
obj-y += clk-tz1090-gate-bank.o
obj-y += clk-tz1090-mux-bank.o
diff --git a/drivers/clk/tz1090/clk-tz1090-deleter.c b/drivers/clk/tz1090/clk-tz1090-deleter.c
new file mode 100644
index 0000000..9ec604d
--- /dev/null
+++ b/drivers/clk/tz1090/clk-tz1090-deleter.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2012-2014 Imagination Technologies 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.
+ *
+ * Clock deleter in TZ1090
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+#include "clk.h"
+
+/**
+ * struct tz1090_clk_deleter_priv - Clock deleter
+ *
+ * @hw: handle between common and hardware-specific interfaces
+ * @reg: delete register
+ * @period: cycle period
+ * @mask: bit mask of delete field
+ * @shift: start bit of delete field
+ *
+ * Deleter in TZ1090, allowing up to period-1 out of each period cycles to be
+ * deleted.
+ */
+struct tz1090_clk_deleter_priv {
+ struct clk_hw hw;
+ void __iomem *reg;
+ u32 period;
+ u32 mask;
+ u8 shift;
+};
+
+#define to_tz1090_clk_deleter(_hw) \
+ container_of(_hw, struct tz1090_clk_deleter_priv, hw)
+
+static unsigned long tz1090_clk_deleter_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct tz1090_clk_deleter_priv *deleter = to_tz1090_clk_deleter(hw);
+ u32 delete;
+ u64 rate;
+
+ delete = (readl(deleter->reg) & deleter->mask) >> deleter->shift;
+ rate = (u64)parent_rate * (deleter->period - delete);
+ do_div(rate, deleter->period);
+ return rate;
+}
+
+static const struct clk_ops tz1090_clk_deleter_ops = {
+ .recalc_rate = tz1090_clk_deleter_recalc_rate,
+};
+
+/**
+ * __register_deleter() - register a clock deleter
+ * @name: name of this clock
+ * @parent_name: name of clock's parent
+ * @flags: framework-specific flags
+ * @reg: register address to adjust deleter
+ * @period: delete cycle period
+ * @mask: mask of delete field
+ * @shift: start bit of delete field
+ *
+ * Register a TZ1090 clock deleter with the clock framework.
+ */
+static struct clk *__init __register_deleter(const char *name,
+ const char *parent_name,
+ unsigned long flags,
+ void __iomem *reg,
+ u32 period,
+ u32 mask,
+ u8 shift)
+{
+ struct tz1090_clk_deleter_priv *deleter;
+ struct clk *clk;
+ struct clk_init_data init;
+
+ /* allocate the deleter */
+ deleter = kzalloc(sizeof(struct tz1090_clk_deleter_priv), GFP_KERNEL);
+ if (!deleter)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &tz1090_clk_deleter_ops;
+ init.flags = flags | CLK_IS_BASIC;
+ init.parent_names = (parent_name ? &parent_name : NULL);
+ init.num_parents = (parent_name ? 1 : 0);
+
+ /* struct tz1090_clk_deleter_priv assignments */
+ deleter->reg = reg;
+ deleter->period = period;
+ deleter->mask = mask;
+ deleter->shift = shift;
+ deleter->hw.init = &init;
+
+ /* register the clock */
+ clk = clk_register(NULL, &deleter->hw);
+
+ if (IS_ERR(clk))
+ kfree(deleter);
+
+ return clk;
+}
+
+/**
+ * tz1090_clk_register_deleters() - Register set of deleters with a provider.
+ * @p: TZ1090 clock provider.
+ * @deleters: Array of deleter descriptions.
+ * @count Number of deleters described in the array.
+ */
+void __init tz1090_clk_register_deleters(struct tz1090_clk_provider *p,
+ const struct tz1090_clk_deleter *deleters,
+ unsigned int count)
+{
+ const struct tz1090_clk_deleter *del;
+ struct clk *clk;
+ unsigned int i;
+
+ for (del = deleters, i = 0; i < count; ++del, ++i) {
+ clk = __register_deleter(tz1090_clk_xlate(p, del->name),
+ tz1090_clk_xlate(p, del->parent), 0,
+ p->base + del->reg, 1024, 0x3ff, 0);
+ p->clk_data.clks[del->id] = clk;
+ }
+}
diff --git a/drivers/clk/tz1090/clk.h b/drivers/clk/tz1090/clk.h
index c9fe6ca..8f90908 100644
--- a/drivers/clk/tz1090/clk.h
+++ b/drivers/clk/tz1090/clk.h
@@ -135,4 +135,35 @@ struct tz1090_clk_mux_bank {
void tz1090_clk_register_mux_bank(struct tz1090_clk_provider *p,
const struct tz1090_clk_mux_bank *bank);
+
+/* Deleters */
+
+/**
+ * struct tz1090_clk_deleter - Describes a clock deleter.
+ * @id: Id of output clock in provider.
+ * @reg: Offset of deleter register in the MMIO region.
+ * @name: Name of deleted clock to provide.
+ * @parent: Name of parent/source clocks.
+ *
+ * The deleter is assumed to have a period of 1024.
+ */
+struct tz1090_clk_deleter {
+ unsigned int id;
+ unsigned long reg;
+ const char *name;
+ const char *parent;
+};
+
+#define DEL(_id, _parent, _name, _reg) \
+ { \
+ .id = (_id), \
+ .reg = (_reg), \
+ .name = (_name), \
+ .parent = (_parent), \
+ }
+
+void tz1090_clk_register_deleters(struct tz1090_clk_provider *p,
+ const struct tz1090_clk_deleter *deleters,
+ unsigned int count);
+
#endif
--
2.0.4
--
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