[PATCH v3] clk: exynos5420: Remove aclk66_peric from the clock tree description

[PATCH v3] clk: exynos5420: Remove aclk66_peric from the clock tree description

[Doug Anderson]

The "aclk66_peric" clock is a gate clock with a whole bunch of gates
underneath it.  This big gate isn't very useful to include in our
clock tree.  If any of the children need to be turned on then the big
gate will need to be on anyway.  ...and there are plenty of other "big
gates" that aren't described in our clock tree, some of which shut off
collections of clocks that have no relationship in the hierarchy so
are hard to model.

"aclk66_peric" is causing earlyprintk problems since it gets disabled
as part of the boot process, so let's just remove it.

Strangely (and for no good reason) this clock is exported as part of
the common clock bindings.  Remove it since there are no in-kernel
device trees using it and no reason anyone out of tree should refer to
it either.

Signed-off-by: Doug Anderson <dianders@chromium.org>
---
Changes in v3:
- Now just remove aclk66_peric from the tree as suggested by Tomasz.

Changes in v2:
- Use GATE_A and clk_get().  Save the clock for putting later.
- Return 0 from exynos5420_clk_late_init().

 drivers/clk/samsung/clk-exynos5420.c   | 85 ++++++++++++++++++++++------------
 include/dt-bindings/clock/exynos5420.h |  1 -
 2 files changed, 55 insertions(+), 31 deletions(-)

diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
index 9d7d7ee..61eccf0 100644
--- a/drivers/clk/samsung/clk-exynos5420.c
+++ b/drivers/clk/samsung/clk-exynos5420.c
@@ -890,8 +890,6 @@ static struct samsung_gate_clock exynos5x_gate_clks[] __initdata = {
 			GATE_BUS_TOP, 9, CLK_IGNORE_UNUSED, 0),
 	GATE(0, "aclk66_psgen", "mout_user_aclk66_psgen",
 			GATE_BUS_TOP, 10, CLK_IGNORE_UNUSED, 0),
-	GATE(CLK_ACLK66_PERIC, "aclk66_peric", "mout_user_aclk66_peric",
-			GATE_BUS_TOP, 11, CLK_IGNORE_UNUSED, 0),
 	GATE(0, "aclk266_isp", "mout_user_aclk266_isp",
 			GATE_BUS_TOP, 13, 0, 0),
 	GATE(0, "aclk166", "mout_user_aclk166",
@@ -994,34 +992,61 @@ static struct samsung_gate_clock exynos5x_gate_clks[] __initdata = {
 			SRC_MASK_FSYS, 24, CLK_SET_RATE_PARENT, 0),
 
 	/* PERIC Block */
-	GATE(CLK_UART0, "uart0", "aclk66_peric", GATE_IP_PERIC, 0, 0, 0),
-	GATE(CLK_UART1, "uart1", "aclk66_peric", GATE_IP_PERIC, 1, 0, 0),
-	GATE(CLK_UART2, "uart2", "aclk66_peric", GATE_IP_PERIC, 2, 0, 0),
-	GATE(CLK_UART3, "uart3", "aclk66_peric", GATE_IP_PERIC, 3, 0, 0),
-	GATE(CLK_I2C0, "i2c0", "aclk66_peric", GATE_IP_PERIC, 6, 0, 0),
-	GATE(CLK_I2C1, "i2c1", "aclk66_peric", GATE_IP_PERIC, 7, 0, 0),
-	GATE(CLK_I2C2, "i2c2", "aclk66_peric", GATE_IP_PERIC, 8, 0, 0),
-	GATE(CLK_I2C3, "i2c3", "aclk66_peric", GATE_IP_PERIC, 9, 0, 0),
-	GATE(CLK_USI0, "usi0", "aclk66_peric", GATE_IP_PERIC, 10, 0, 0),
-	GATE(CLK_USI1, "usi1", "aclk66_peric", GATE_IP_PERIC, 11, 0, 0),
-	GATE(CLK_USI2, "usi2", "aclk66_peric", GATE_IP_PERIC, 12, 0, 0),
-	GATE(CLK_USI3, "usi3", "aclk66_peric", GATE_IP_PERIC, 13, 0, 0),
-	GATE(CLK_I2C_HDMI, "i2c_hdmi", "aclk66_peric", GATE_IP_PERIC, 14, 0, 0),
-	GATE(CLK_TSADC, "tsadc", "aclk66_peric", GATE_IP_PERIC, 15, 0, 0),
-	GATE(CLK_SPI0, "spi0", "aclk66_peric", GATE_IP_PERIC, 16, 0, 0),
-	GATE(CLK_SPI1, "spi1", "aclk66_peric", GATE_IP_PERIC, 17, 0, 0),
-	GATE(CLK_SPI2, "spi2", "aclk66_peric", GATE_IP_PERIC, 18, 0, 0),
-	GATE(CLK_I2S1, "i2s1", "aclk66_peric", GATE_IP_PERIC, 20, 0, 0),
-	GATE(CLK_I2S2, "i2s2", "aclk66_peric", GATE_IP_PERIC, 21, 0, 0),
-	GATE(CLK_PCM1, "pcm1", "aclk66_peric", GATE_IP_PERIC, 22, 0, 0),
-	GATE(CLK_PCM2, "pcm2", "aclk66_peric", GATE_IP_PERIC, 23, 0, 0),
-	GATE(CLK_PWM, "pwm", "aclk66_peric", GATE_IP_PERIC, 24, 0, 0),
-	GATE(CLK_SPDIF, "spdif", "aclk66_peric", GATE_IP_PERIC, 26, 0, 0),
-	GATE(CLK_USI4, "usi4", "aclk66_peric", GATE_IP_PERIC, 28, 0, 0),
-	GATE(CLK_USI5, "usi5", "aclk66_peric", GATE_IP_PERIC, 30, 0, 0),
-	GATE(CLK_USI6, "usi6", "aclk66_peric", GATE_IP_PERIC, 31, 0, 0),
-
-	GATE(CLK_KEYIF, "keyif", "aclk66_peric", GATE_BUS_PERIC, 22, 0, 0),
+	GATE(CLK_UART0, "uart0", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 0, 0, 0),
+	GATE(CLK_UART1, "uart1", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 1, 0, 0),
+	GATE(CLK_UART2, "uart2", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 2, 0, 0),
+	GATE(CLK_UART3, "uart3", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 3, 0, 0),
+	GATE(CLK_I2C0, "i2c0", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 6, 0, 0),
+	GATE(CLK_I2C1, "i2c1", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 7, 0, 0),
+	GATE(CLK_I2C2, "i2c2", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 8, 0, 0),
+	GATE(CLK_I2C3, "i2c3", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 9, 0, 0),
+	GATE(CLK_USI0, "usi0", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 10, 0, 0),
+	GATE(CLK_USI1, "usi1", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 11, 0, 0),
+	GATE(CLK_USI2, "usi2", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 12, 0, 0),
+	GATE(CLK_USI3, "usi3", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 13, 0, 0),
+	GATE(CLK_I2C_HDMI, "i2c_hdmi", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 14, 0, 0),
+	GATE(CLK_TSADC, "tsadc", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 15, 0, 0),
+	GATE(CLK_SPI0, "spi0", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 16, 0, 0),
+	GATE(CLK_SPI1, "spi1", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 17, 0, 0),
+	GATE(CLK_SPI2, "spi2", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 18, 0, 0),
+	GATE(CLK_I2S1, "i2s1", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 20, 0, 0),
+	GATE(CLK_I2S2, "i2s2", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 21, 0, 0),
+	GATE(CLK_PCM1, "pcm1", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 22, 0, 0),
+	GATE(CLK_PCM2, "pcm2", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 23, 0, 0),
+	GATE(CLK_PWM, "pwm", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 24, 0, 0),
+	GATE(CLK_SPDIF, "spdif", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 26, 0, 0),
+	GATE(CLK_USI4, "usi4", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 28, 0, 0),
+	GATE(CLK_USI5, "usi5", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 30, 0, 0),
+	GATE(CLK_USI6, "usi6", "mout_user_aclk66_peric",
+			GATE_IP_PERIC, 31, 0, 0),
+
+	GATE(CLK_KEYIF, "keyif", "mout_user_aclk66_peric",
+			GATE_BUS_PERIC, 22, 0, 0),
 
 	/* PERIS Block */
 	GATE(CLK_CHIPID, "chipid", "aclk66_psgen",
diff --git a/include/dt-bindings/clock/exynos5420.h b/include/dt-bindings/clock/exynos5420.h
index 97dcb89..14e1c8f 100644
--- a/include/dt-bindings/clock/exynos5420.h
+++ b/include/dt-bindings/clock/exynos5420.h
@@ -63,7 +63,6 @@
 #define CLK_SCLK_MPHY_IXTAL24	161
 
 /* gate clocks */
-#define CLK_ACLK66_PERIC	256
 #define CLK_UART0		257
 #define CLK_UART1		258
 #define CLK_UART2		259
-- 
2.0.0.526.g5318336

Re: [PATCH v3] clk: exynos5420: Remove aclk66_peric from the clock tree description

[Tomasz Figa]

On 05.06.2014 22:35, Doug Anderson wrote:
> The "aclk66_peric" clock is a gate clock with a whole bunch of gates
> underneath it.  This big gate isn't very useful to include in our
> clock tree.  If any of the children need to be turned on then the big
> gate will need to be on anyway.  ...and there are plenty of other "big
> gates" that aren't described in our clock tree, some of which shut off
> collections of clocks that have no relationship in the hierarchy so
> are hard to model.
> 
> "aclk66_peric" is causing earlyprintk problems since it gets disabled
> as part of the boot process, so let's just remove it.
> 
> Strangely (and for no good reason) this clock is exported as part of
> the common clock bindings.  Remove it since there are no in-kernel
> device trees using it and no reason anyone out of tree should refer to
> it either.
> 
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> ---
> Changes in v3:
> - Now just remove aclk66_peric from the tree as suggested by Tomasz.
> 
> Changes in v2:
> - Use GATE_A and clk_get().  Save the clock for putting later.
> - Return 0 from exynos5420_clk_late_init().
> 
>  drivers/clk/samsung/clk-exynos5420.c   | 85 ++++++++++++++++++++++------------
>  include/dt-bindings/clock/exynos5420.h |  1 -
>  2 files changed, 55 insertions(+), 31 deletions(-)
> 

Mike, I can take this patch to my tree as a fix for 3.16-rc, or if still
possible and you don't mind, feel free to apply it directly with my ACK:

Acked-by: Tomasz Figa <t.figa@samsung.com>

Best regards,
Tomasz

Re: [PATCH v3] clk: exynos5420: Remove aclk66_peric from the clock tree description

[Mike Turquette]

Quoting Tomasz Figa (2014-06-05 15:26:31)
> On 05.06.2014 22:35, Doug Anderson wrote:
> > The "aclk66_peric" clock is a gate clock with a whole bunch of gates
> > underneath it.  This big gate isn't very useful to include in our
> > clock tree.  If any of the children need to be turned on then the big
> > gate will need to be on anyway.  ...and there are plenty of other "big
> > gates" that aren't described in our clock tree, some of which shut off
> > collections of clocks that have no relationship in the hierarchy so
> > are hard to model.
> > 
> > "aclk66_peric" is causing earlyprintk problems since it gets disabled
> > as part of the boot process, so let's just remove it.
> > 
> > Strangely (and for no good reason) this clock is exported as part of
> > the common clock bindings.  Remove it since there are no in-kernel
> > device trees using it and no reason anyone out of tree should refer to
> > it either.
> > 
> > Signed-off-by: Doug Anderson <dianders@chromium.org>
> > ---
> > Changes in v3:
> > - Now just remove aclk66_peric from the tree as suggested by Tomasz.
> > 
> > Changes in v2:
> > - Use GATE_A and clk_get().  Save the clock for putting later.
> > - Return 0 from exynos5420_clk_late_init().
> > 
> >  drivers/clk/samsung/clk-exynos5420.c   | 85 ++++++++++++++++++++++------------
> >  include/dt-bindings/clock/exynos5420.h |  1 -
> >  2 files changed, 55 insertions(+), 31 deletions(-)
> > 
> 
> Mike, I can take this patch to my tree as a fix for 3.16-rc, or if still
> possible and you don't mind, feel free to apply it directly with my ACK:
> 
> Acked-by: Tomasz Figa <t.figa@samsung.com>

I'll send a second PR next week that includes this.

Regards,
Mike

> 
> Best regards,
> Tomasz

Re: [PATCH v3] clk: exynos5420: Remove aclk66_peric from the clock tree description

[Doug Anderson]

Tomasz,

On Fri, Jun 6, 2014 at 4:41 PM, Mike Turquette <mturquette@linaro.org> wrote:
> Quoting Tomasz Figa (2014-06-05 15:26:31)
>> On 05.06.2014 22:35, Doug Anderson wrote:
>> > The "aclk66_peric" clock is a gate clock with a whole bunch of gates
>> > underneath it.  This big gate isn't very useful to include in our
>> > clock tree.  If any of the children need to be turned on then the big
>> > gate will need to be on anyway.  ...and there are plenty of other "big
>> > gates" that aren't described in our clock tree, some of which shut off
>> > collections of clocks that have no relationship in the hierarchy so
>> > are hard to model.
>> >
>> > "aclk66_peric" is causing earlyprintk problems since it gets disabled
>> > as part of the boot process, so let's just remove it.
>> >
>> > Strangely (and for no good reason) this clock is exported as part of
>> > the common clock bindings.  Remove it since there are no in-kernel
>> > device trees using it and no reason anyone out of tree should refer to
>> > it either.
>> >
>> > Signed-off-by: Doug Anderson <dianders@chromium.org>
>> > ---
>> > Changes in v3:
>> > - Now just remove aclk66_peric from the tree as suggested by Tomasz.
>> >
>> > Changes in v2:
>> > - Use GATE_A and clk_get().  Save the clock for putting later.
>> > - Return 0 from exynos5420_clk_late_init().
>> >
>> >  drivers/clk/samsung/clk-exynos5420.c   | 85 ++++++++++++++++++++++------------
>> >  include/dt-bindings/clock/exynos5420.h |  1 -
>> >  2 files changed, 55 insertions(+), 31 deletions(-)
>> >
>>
>> Mike, I can take this patch to my tree as a fix for 3.16-rc, or if still
>> possible and you don't mind, feel free to apply it directly with my ACK:
>>
>> Acked-by: Tomasz Figa <t.figa@samsung.com>
>
> I'll send a second PR next week that includes this.

This doesn't apply cleanly to Mike's tree.  Can you add it to your
tree and send it out for 3.16?  Mike said you should add his Ack and
I've confirmed that the patch applies cleanly to the most recent
linuxnext (next-20140606) as well as to the top of your
'samsung-clk-next' tree (2ce16c5 clk: samsung: exynos3250: Add clocks
using common clock framework).

Thanks!

-Doug

Re: [PATCH v3] clk: exynos5420: Remove aclk66_peric from the clock tree description

[Mike Turquette]

Quoting Doug Anderson (2014-06-05 13:35:14)
> The "aclk66_peric" clock is a gate clock with a whole bunch of gates
> underneath it.  This big gate isn't very useful to include in our
> clock tree.  If any of the children need to be turned on then the big
> gate will need to be on anyway.  ...and there are plenty of other "big
> gates" that aren't described in our clock tree, some of which shut off
> collections of clocks that have no relationship in the hierarchy so
> are hard to model.

I think this is a common problem. On OMAP we have something similar to
this called "clock domains" or "clkdm" and it has been historically
handled outside of the Linux clock framework[1]. There is a relationship
to the clock framework of course and in the future it might be
worthwhile to see if there is a generic way to handle this stuff.

> 
> "aclk66_peric" is causing earlyprintk problems since it gets disabled
> as part of the boot process, so let's just remove it.
> 
> Strangely (and for no good reason) this clock is exported as part of
> the common clock bindings.  Remove it since there are no in-kernel
> device trees using it and no reason anyone out of tree should refer to
> it either.

So Linux has no control over the big gate now, correct? You are
dependent on the bootloader to ungate this thing?

Regards,
Mike

[1] http://deferred.io/images/clkdm.png

> 
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> ---
> Changes in v3:
> - Now just remove aclk66_peric from the tree as suggested by Tomasz.
> 
> Changes in v2:
> - Use GATE_A and clk_get().  Save the clock for putting later.
> - Return 0 from exynos5420_clk_late_init().
> 
>  drivers/clk/samsung/clk-exynos5420.c   | 85 ++++++++++++++++++++++------------
>  include/dt-bindings/clock/exynos5420.h |  1 -
>  2 files changed, 55 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
> index 9d7d7ee..61eccf0 100644
> --- a/drivers/clk/samsung/clk-exynos5420.c
> +++ b/drivers/clk/samsung/clk-exynos5420.c
> @@ -890,8 +890,6 @@ static struct samsung_gate_clock exynos5x_gate_clks[] __initdata = {
>                         GATE_BUS_TOP, 9, CLK_IGNORE_UNUSED, 0),
>         GATE(0, "aclk66_psgen", "mout_user_aclk66_psgen",
>                         GATE_BUS_TOP, 10, CLK_IGNORE_UNUSED, 0),
> -       GATE(CLK_ACLK66_PERIC, "aclk66_peric", "mout_user_aclk66_peric",
> -                       GATE_BUS_TOP, 11, CLK_IGNORE_UNUSED, 0),
>         GATE(0, "aclk266_isp", "mout_user_aclk266_isp",
>                         GATE_BUS_TOP, 13, 0, 0),
>         GATE(0, "aclk166", "mout_user_aclk166",
> @@ -994,34 +992,61 @@ static struct samsung_gate_clock exynos5x_gate_clks[] __initdata = {
>                         SRC_MASK_FSYS, 24, CLK_SET_RATE_PARENT, 0),
>  
>         /* PERIC Block */
> -       GATE(CLK_UART0, "uart0", "aclk66_peric", GATE_IP_PERIC, 0, 0, 0),
> -       GATE(CLK_UART1, "uart1", "aclk66_peric", GATE_IP_PERIC, 1, 0, 0),
> -       GATE(CLK_UART2, "uart2", "aclk66_peric", GATE_IP_PERIC, 2, 0, 0),
> -       GATE(CLK_UART3, "uart3", "aclk66_peric", GATE_IP_PERIC, 3, 0, 0),
> -       GATE(CLK_I2C0, "i2c0", "aclk66_peric", GATE_IP_PERIC, 6, 0, 0),
> -       GATE(CLK_I2C1, "i2c1", "aclk66_peric", GATE_IP_PERIC, 7, 0, 0),
> -       GATE(CLK_I2C2, "i2c2", "aclk66_peric", GATE_IP_PERIC, 8, 0, 0),
> -       GATE(CLK_I2C3, "i2c3", "aclk66_peric", GATE_IP_PERIC, 9, 0, 0),
> -       GATE(CLK_USI0, "usi0", "aclk66_peric", GATE_IP_PERIC, 10, 0, 0),
> -       GATE(CLK_USI1, "usi1", "aclk66_peric", GATE_IP_PERIC, 11, 0, 0),
> -       GATE(CLK_USI2, "usi2", "aclk66_peric", GATE_IP_PERIC, 12, 0, 0),
> -       GATE(CLK_USI3, "usi3", "aclk66_peric", GATE_IP_PERIC, 13, 0, 0),
> -       GATE(CLK_I2C_HDMI, "i2c_hdmi", "aclk66_peric", GATE_IP_PERIC, 14, 0, 0),
> -       GATE(CLK_TSADC, "tsadc", "aclk66_peric", GATE_IP_PERIC, 15, 0, 0),
> -       GATE(CLK_SPI0, "spi0", "aclk66_peric", GATE_IP_PERIC, 16, 0, 0),
> -       GATE(CLK_SPI1, "spi1", "aclk66_peric", GATE_IP_PERIC, 17, 0, 0),
> -       GATE(CLK_SPI2, "spi2", "aclk66_peric", GATE_IP_PERIC, 18, 0, 0),
> -       GATE(CLK_I2S1, "i2s1", "aclk66_peric", GATE_IP_PERIC, 20, 0, 0),
> -       GATE(CLK_I2S2, "i2s2", "aclk66_peric", GATE_IP_PERIC, 21, 0, 0),
> -       GATE(CLK_PCM1, "pcm1", "aclk66_peric", GATE_IP_PERIC, 22, 0, 0),
> -       GATE(CLK_PCM2, "pcm2", "aclk66_peric", GATE_IP_PERIC, 23, 0, 0),
> -       GATE(CLK_PWM, "pwm", "aclk66_peric", GATE_IP_PERIC, 24, 0, 0),
> -       GATE(CLK_SPDIF, "spdif", "aclk66_peric", GATE_IP_PERIC, 26, 0, 0),
> -       GATE(CLK_USI4, "usi4", "aclk66_peric", GATE_IP_PERIC, 28, 0, 0),
> -       GATE(CLK_USI5, "usi5", "aclk66_peric", GATE_IP_PERIC, 30, 0, 0),
> -       GATE(CLK_USI6, "usi6", "aclk66_peric", GATE_IP_PERIC, 31, 0, 0),
> -
> -       GATE(CLK_KEYIF, "keyif", "aclk66_peric", GATE_BUS_PERIC, 22, 0, 0),
> +       GATE(CLK_UART0, "uart0", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 0, 0, 0),
> +       GATE(CLK_UART1, "uart1", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 1, 0, 0),
> +       GATE(CLK_UART2, "uart2", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 2, 0, 0),
> +       GATE(CLK_UART3, "uart3", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 3, 0, 0),
> +       GATE(CLK_I2C0, "i2c0", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 6, 0, 0),
> +       GATE(CLK_I2C1, "i2c1", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 7, 0, 0),
> +       GATE(CLK_I2C2, "i2c2", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 8, 0, 0),
> +       GATE(CLK_I2C3, "i2c3", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 9, 0, 0),
> +       GATE(CLK_USI0, "usi0", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 10, 0, 0),
> +       GATE(CLK_USI1, "usi1", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 11, 0, 0),
> +       GATE(CLK_USI2, "usi2", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 12, 0, 0),
> +       GATE(CLK_USI3, "usi3", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 13, 0, 0),
> +       GATE(CLK_I2C_HDMI, "i2c_hdmi", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 14, 0, 0),
> +       GATE(CLK_TSADC, "tsadc", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 15, 0, 0),
> +       GATE(CLK_SPI0, "spi0", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 16, 0, 0),
> +       GATE(CLK_SPI1, "spi1", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 17, 0, 0),
> +       GATE(CLK_SPI2, "spi2", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 18, 0, 0),
> +       GATE(CLK_I2S1, "i2s1", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 20, 0, 0),
> +       GATE(CLK_I2S2, "i2s2", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 21, 0, 0),
> +       GATE(CLK_PCM1, "pcm1", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 22, 0, 0),
> +       GATE(CLK_PCM2, "pcm2", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 23, 0, 0),
> +       GATE(CLK_PWM, "pwm", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 24, 0, 0),
> +       GATE(CLK_SPDIF, "spdif", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 26, 0, 0),
> +       GATE(CLK_USI4, "usi4", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 28, 0, 0),
> +       GATE(CLK_USI5, "usi5", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 30, 0, 0),
> +       GATE(CLK_USI6, "usi6", "mout_user_aclk66_peric",
> +                       GATE_IP_PERIC, 31, 0, 0),
> +
> +       GATE(CLK_KEYIF, "keyif", "mout_user_aclk66_peric",
> +                       GATE_BUS_PERIC, 22, 0, 0),
>  
>         /* PERIS Block */
>         GATE(CLK_CHIPID, "chipid", "aclk66_psgen",
> diff --git a/include/dt-bindings/clock/exynos5420.h b/include/dt-bindings/clock/exynos5420.h
> index 97dcb89..14e1c8f 100644
> --- a/include/dt-bindings/clock/exynos5420.h
> +++ b/include/dt-bindings/clock/exynos5420.h
> @@ -63,7 +63,6 @@
>  #define CLK_SCLK_MPHY_IXTAL24  161
>  
>  /* gate clocks */
> -#define CLK_ACLK66_PERIC       256
>  #define CLK_UART0              257
>  #define CLK_UART1              258
>  #define CLK_UART2              259
> -- 
> 2.0.0.526.g5318336
> 

Re: [PATCH v3] clk: exynos5420: Remove aclk66_peric from the clock tree description

[Doug Anderson]

Mike,

On Thu, Jun 5, 2014 at 5:03 PM, Mike Turquette <mturquette@linaro.org> wrote:
> Quoting Doug Anderson (2014-06-05 13:35:14)
>> The "aclk66_peric" clock is a gate clock with a whole bunch of gates
>> underneath it.  This big gate isn't very useful to include in our
>> clock tree.  If any of the children need to be turned on then the big
>> gate will need to be on anyway.  ...and there are plenty of other "big
>> gates" that aren't described in our clock tree, some of which shut off
>> collections of clocks that have no relationship in the hierarchy so
>> are hard to model.
>
> I think this is a common problem. On OMAP we have something similar to
> this called "clock domains" or "clkdm" and it has been historically
> handled outside of the Linux clock framework[1]. There is a relationship
> to the clock framework of course and in the future it might be
> worthwhile to see if there is a generic way to handle this stuff.

That sounds like something that would be nice to solve, but it's not
going to happen now.

On the off chance that the user manual mentioned the existence of one
of these "big gate" bits, it tends to not be very specific about
_exactly_ which sets of clocks it disables.

Tracking down every one of these would be hugely time consuming.
Also: as Tomasz has indicated they don't provide a huge amount of
benefit since we're already dealing with clocks on a more fine-grained
level...


>> "aclk66_peric" is causing earlyprintk problems since it gets disabled
>> as part of the boot process, so let's just remove it.
>>
>> Strangely (and for no good reason) this clock is exported as part of
>> the common clock bindings.  Remove it since there are no in-kernel
>> device trees using it and no reason anyone out of tree should refer to
>> it either.
>
> So Linux has no control over the big gate now, correct? You are
> dependent on the bootloader to ungate this thing?

A better way to put it is that you're dependent on the bootloader not
to gate it.

...but that's also true for pretty much any clock marked IGNORE_UNUSED
and not explicitly enabled anywhere.


Are you opposed to this landing as-is to unblock things and people can
continue to work on the clock driver to make it even better?

-Doug

Re: [PATCH v3] clk: exynos5420: Remove aclk66_peric from the clock tree description

[Mike Turquette]

Quoting Doug Anderson (2014-06-05 17:46:23)
> Mike,
> 
> On Thu, Jun 5, 2014 at 5:03 PM, Mike Turquette <mturquette@linaro.org> wrote:
> > Quoting Doug Anderson (2014-06-05 13:35:14)
> >> The "aclk66_peric" clock is a gate clock with a whole bunch of gates
> >> underneath it.  This big gate isn't very useful to include in our
> >> clock tree.  If any of the children need to be turned on then the big
> >> gate will need to be on anyway.  ...and there are plenty of other "big
> >> gates" that aren't described in our clock tree, some of which shut off
> >> collections of clocks that have no relationship in the hierarchy so
> >> are hard to model.
> >
> > I think this is a common problem. On OMAP we have something similar to
> > this called "clock domains" or "clkdm" and it has been historically
> > handled outside of the Linux clock framework[1]. There is a relationship
> > to the clock framework of course and in the future it might be
> > worthwhile to see if there is a generic way to handle this stuff.
> 
> That sounds like something that would be nice to solve, but it's not
> going to happen now.
> 
> On the off chance that the user manual mentioned the existence of one
> of these "big gate" bits, it tends to not be very specific about
> _exactly_ which sets of clocks it disables.
> 
> Tracking down every one of these would be hugely time consuming.
> Also: as Tomasz has indicated they don't provide a huge amount of
> benefit since we're already dealing with clocks on a more fine-grained
> level...

Sounds like you are dealing with crappy documentation :-(

> 
> 
> >> "aclk66_peric" is causing earlyprintk problems since it gets disabled
> >> as part of the boot process, so let's just remove it.
> >>
> >> Strangely (and for no good reason) this clock is exported as part of
> >> the common clock bindings.  Remove it since there are no in-kernel
> >> device trees using it and no reason anyone out of tree should refer to
> >> it either.
> >
> > So Linux has no control over the big gate now, correct? You are
> > dependent on the bootloader to ungate this thing?
> 
> A better way to put it is that you're dependent on the bootloader not
> to gate it.
> 
> ...but that's also true for pretty much any clock marked IGNORE_UNUSED
> and not explicitly enabled anywhere.
> 
> 
> Are you opposed to this landing as-is to unblock things and people can
> continue to work on the clock driver to make it even better?

No. I'm just trying to understand how things work so that we can arrive
to the right decision. I know what it is like to try and quickly unblock
everyone else and the rush to do so often leads to less awesome
solutions.

Anyways, getting back on point, Tomasz was right about the whole clk_get
thing. So I'm happy to take either V1 or V3 of your patch. I will be
submitting a second PR for 3.16 next week and it will include whichever
version you and Tomasz agree is best.

Regards,
Mike

> 
> -Doug

Re: [PATCH v3] clk: exynos5420: Remove aclk66_peric from the clock tree description

[Doug Anderson]

Mike,

On Fri, Jun 6, 2014 at 3:31 PM, Mike Turquette <mturquette-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> Anyways, getting back on point, Tomasz was right about the whole clk_get
> thing. So I'm happy to take either V1 or V3 of your patch. I will be
> submitting a second PR for 3.16 next week and it will include whichever
> version you and Tomasz agree is best.

I like V3 slightly better and it has Tomasz's Ack.  Unless he emails
and suggests that he really V1 better then I'd say go with V3.  If we
go back to V1 we'll need to add the "return 0", which I'm happy to do.

Thanks!

-Doug
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Re: [PATCH v3] clk: exynos5420: Remove aclk66_peric from the clock tree description

[Tomasz Figa]

On 05.06.2014 22:35, Doug Anderson wrote:
> The "aclk66_peric" clock is a gate clock with a whole bunch of gates
> underneath it.  This big gate isn't very useful to include in our
> clock tree.  If any of the children need to be turned on then the big
> gate will need to be on anyway.  ...and there are plenty of other "big
> gates" that aren't described in our clock tree, some of which shut off
> collections of clocks that have no relationship in the hierarchy so
> are hard to model.
> 
> "aclk66_peric" is causing earlyprintk problems since it gets disabled
> as part of the boot process, so let's just remove it.
> 
> Strangely (and for no good reason) this clock is exported as part of
> the common clock bindings.  Remove it since there are no in-kernel
> device trees using it and no reason anyone out of tree should refer to
> it either.
> 
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> ---
> Changes in v3:
> - Now just remove aclk66_peric from the tree as suggested by Tomasz.
> 
> Changes in v2:
> - Use GATE_A and clk_get().  Save the clock for putting later.
> - Return 0 from exynos5420_clk_late_init().
> 
>  drivers/clk/samsung/clk-exynos5420.c   | 85 ++++++++++++++++++++++------------
>  include/dt-bindings/clock/exynos5420.h |  1 -
>  2 files changed, 55 insertions(+), 31 deletions(-)

Applied as a fix for 3.16.

Best regards,
Tomasz