From: Rob Herring <robherring2@gmail.com>
To: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 4/4] clk: Add simple gated clock
Date: Fri, 20 May 2011 22:19:56 +0000 [thread overview]
Message-ID: <4DD6E90C.9030109@gmail.com> (raw)
In-Reply-To: <1305876469.327589.409938867568.4.gpush@pororo>
On 05/20/2011 02:27 AM, Jeremy Kerr wrote:
> Signed-off-by: Jeremy Kerr<jeremy.kerr@canonical.com>
>
> ---
> drivers/clk/Kconfig | 4 ++++
> drivers/clk/Makefile | 1 +
> drivers/clk/clk-gate.c | 41 +++++++++++++++++++++++++++++++++++++++++
> include/linux/clk.h | 13 +++++++++++++
> 4 files changed, 59 insertions(+)
>
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 0a27963..75d2902 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -9,3 +9,7 @@ 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..833e0da
> --- /dev/null
> +++ b/drivers/clk/clk-gate.c
> @@ -0,0 +1,41 @@
> +
> +#include<linux/clk.h>
> +#include<linux/module.h>
> +#include<asm/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 int clk_gate_enable(struct clk_hw *clk)
> +{
> + struct clk_gate *gate = to_clk_gate(clk);
> + u32 reg;
> +
> + reg = __raw_readl(gate->reg);
> + reg |= 1<< gate->bit_idx;
> + __raw_writel(reg, gate->reg);
This should be protected with a spinlock for h/w access. You could have
a mixture of enable bits with divider fields in one register, so the
enable lock won't help here. However, you would have to find a way to
have a common spinlock for all accesses to the h/w.
Rob
next prev parent reply other threads:[~2011-05-20 22:19 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-20 7:27 [PATCH 0/4] Add a generic struct clk Jeremy Kerr
2011-05-20 7:27 ` [PATCH 4/4] clk: Add simple gated clock Jeremy Kerr
2011-05-20 11:37 ` Arnd Bergmann
2011-05-20 22:19 ` Rob Herring [this message]
2011-05-20 7:27 ` [PATCH 2/4] clk: Implement clk_set_rate Jeremy Kerr
2011-05-20 12:25 ` Sascha Hauer
2011-05-24 7:59 ` Colin Cross
2011-05-25 19:03 ` Sascha Hauer
[not found] ` <1306373867.2875.162.camel@pororo>
2011-05-26 6:54 ` Sascha Hauer
2011-05-30 5:05 ` Mike Frysinger
2011-05-20 7:27 ` [PATCH 3/4] clk: Add fixed-rate clock Jeremy Kerr
2011-05-30 5:01 ` Mike Frysinger
2011-05-30 5:02 ` Mike Frysinger
2011-05-20 7:27 ` [PATCH 1/4] clk: Add a generic clock infrastructure Jeremy Kerr
2011-05-20 11:59 ` Sascha Hauer
2011-05-20 13:25 ` Thomas Gleixner
2011-05-20 13:36 ` Sascha Hauer
2011-05-23 23:55 ` Colin Cross
2011-05-24 7:02 ` Sascha Hauer
2011-05-24 7:51 ` Colin Cross
2011-05-24 8:38 ` Sascha Hauer
2011-05-25 11:22 ` Richard Zhao
2011-05-25 11:43 ` Thomas Gleixner
2011-05-24 4:30 ` viresh kumar
2011-05-25 10:47 ` Richard Zhao
2011-05-30 5:00 ` Mike Frysinger
2011-05-23 23:12 ` [PATCH 0/4] Add a generic struct clk Colin Cross
2011-05-24 6:26 ` Sascha Hauer
2011-05-24 7:31 ` Colin Cross
2011-05-24 8:09 ` Sascha Hauer
2011-05-24 19:41 ` Colin Cross
2011-05-25 2:32 ` Richard Zhao
2011-05-25 6:23 ` Sascha Hauer
2011-05-25 7:51 ` Thomas Gleixner
2011-05-27 14:39 ` Mark Brown
2011-05-24 17:22 ` Richard Zhao
2011-05-24 17:52 ` Colin Cross
2011-05-25 2:08 ` Richard Zhao
2011-05-30 5:20 ` Mike Frysinger
2011-07-10 9:09 ` Mark Brown
2011-07-10 9:50 ` Russell King - ARM Linux
2011-07-10 10:00 ` Russell King - ARM Linux
2011-07-10 11:27 ` Mark Brown
2011-07-10 11:52 ` Russell King - ARM Linux
2011-07-11 2:49 ` Jeremy Kerr
2011-07-11 3:57 ` Mark Brown
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