Mike,
On 09/22/2011 05:26 PM, Mike Turquette wrote:
From: Jeremy Kerr jeremy.kerr@canonical.com
Signed-off-by: Jeremy Kerr jeremy.kerr@canonical.com Signed-off-by: Mark Brown broonie@opensource.wolfsonmicro.com Signed-off-by: Jamie Iles jamie@jamieiles.com Signed-off-by: Mike Turquette mturquette@ti.com
Changes since v1: Add copyright header Fold in Jamie's patch for set-to-disable clks Use BIT macro instead of shift
drivers/clk/Kconfig | 4 ++ drivers/clk/Makefile | 1 + drivers/clk/clk-gate.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/clk.h | 13 ++++++++ 4 files changed, 96 insertions(+), 0 deletions(-) create mode 100644 drivers/clk/clk-gate.c
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index d8313d7..a78967c 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -12,3 +12,7 @@ config GENERIC_CLK config GENERIC_CLK_FIXED bool depends on GENERIC_CLK
+config GENERIC_CLK_GATE
- bool
- depends on GENERIC_CLK
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 9a3325a..d186446 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -2,3 +2,4 @@ obj-$(CONFIG_CLKDEV_LOOKUP) += clkdev.o obj-$(CONFIG_GENERIC_CLK) += clk.o obj-$(CONFIG_GENERIC_CLK_FIXED) += clk-fixed.o +obj-$(CONFIG_GENERIC_CLK_GATE) += clk-gate.o diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c new file mode 100644 index 0000000..a1d8e79 --- /dev/null +++ b/drivers/clk/clk-gate.c @@ -0,0 +1,78 @@ +/*
- Copyright (C) 2010-2011 Canonical Ltd jeremy.kerr@canonical.com
- 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.
- Simple clk gate implementation
- */
+#include <linux/clk.h> +#include <linux/module.h> +#include <asm/io.h>
use linux/io.h
+#define to_clk_gate(clk) container_of(clk, struct clk_gate, hw)
+static unsigned long clk_gate_get_rate(struct clk_hw *clk) +{
- return clk_get_rate(clk_get_parent(clk->clk));
+}
+static void clk_gate_set_bit(struct clk_hw *clk) +{
- struct clk_gate *gate = to_clk_gate(clk);
- u32 reg;
- reg = __raw_readl(gate->reg);
- reg |= BIT(gate->bit_idx);
- __raw_writel(reg, gate->reg);
Don't these read-mod-writes need a spinlock around it?
It's possible to have an enable bits and dividers in the same register. If you did a set_rate and while doing an enable/disable, there would be a problem. Also, it may be 2 different clocks in the same register, so the spinlock needs to be shared and not per clock.
+}
+static void clk_gate_clear_bit(struct clk_hw *clk) +{
- struct clk_gate *gate = to_clk_gate(clk);
- u32 reg;
- reg = __raw_readl(gate->reg);
- reg &= ~BIT(gate->bit_idx);
- __raw_writel(reg, gate->reg);
+}
+static int clk_gate_enable_set(struct clk_hw *clk) +{
- clk_gate_set_bit(clk);
- return 0;
+}
+static void clk_gate_disable_clear(struct clk_hw *clk) +{
- clk_gate_clear_bit(clk);
+}
+struct clk_hw_ops clk_gate_set_enable_ops = {
const?
- .recalc_rate = clk_gate_get_rate,
- .enable = clk_gate_enable_set,
- .disable = clk_gate_disable_clear,
+}; +EXPORT_SYMBOL_GPL(clk_gate_set_enable_ops);
+static int clk_gate_enable_clear(struct clk_hw *clk) +{
- clk_gate_clear_bit(clk);
- return 0;
+}
+static void clk_gate_disable_set(struct clk_hw *clk) +{
- clk_gate_set_bit(clk);
+}
Are these wrapper functions really needed? Just assign set_bit and clear_bit functions directly to the ops structs. Only the ops struct name is exposed to the user.
+struct clk_hw_ops clk_gate_set_disable_ops = {
const?
Rob