* [PATCH v2 2/2] i2c: mv64xxx: Fix clock resource by adding an optional bus clock
@ 2018-01-10 17:07 ` Gregory CLEMENT
0 siblings, 0 replies; 12+ messages in thread
From: Gregory CLEMENT @ 2018-01-10 17:07 UTC (permalink / raw)
To: linux-arm-kernel
On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
is optional because not all the SoCs need them but at least for Armada
7K/8K it is actually mandatory.
The binding documentation is updating accordingly.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
.../devicetree/bindings/i2c/i2c-mv64xxx.txt | 20 ++++++++++++++++++++
drivers/i2c/busses/i2c-mv64xxx.c | 12 +++++++++++-
2 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
index 5c30026921ae..a835b724c738 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
@@ -25,6 +25,15 @@ default frequency is 100kHz
whenever you're using the "allwinner,sun6i-a31-i2c"
compatible.
+ - clocks: : pointers to the reference clocks for this device, the first
+ one is the one used for the clock on the i2c bus, the second
+ one is the clock used for the functional part of the
+ controller
+
+ - clock-names : names of used clocks, mandatory if the second clock is
+ : used, the name must be "core", and "axi_clk" (the latter is
+ only for Armada 7K/8K).
+
Examples:
i2c at 11000 {
@@ -42,3 +51,14 @@ For the Armada XP:
interrupts = <29>;
clock-frequency = <100000>;
};
+
+For the Armada 7040:
+
+ i2c at 701000 {
+ compatible = "marvell,mv78230-i2c";
+ reg = <0x701000 0x20>;
+ interrupts = <29>;
+ clock-frequency = <100000>;
+ clock-names = "core", "axi";
+ clocks = <&core_clock>, <&axi_clock>;
+ };
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index f69066266faa..cce37d8ecf41 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -135,6 +135,7 @@ struct mv64xxx_i2c_data {
u32 freq_m;
u32 freq_n;
struct clk *clk;
+ struct clk *axi_clk;
wait_queue_head_t waitq;
spinlock_t lock;
struct i2c_msg *msg;
@@ -894,13 +895,20 @@ mv64xxx_i2c_probe(struct platform_device *pd)
init_waitqueue_head(&drv_data->waitq);
spin_lock_init(&drv_data->lock);
- /* Not all platforms have a clk */
+ /* Not all platforms have clocks */
drv_data->clk = devm_clk_get(&pd->dev, NULL);
if (IS_ERR(drv_data->clk) && PTR_ERR(drv_data->clk) == -EPROBE_DEFER)
return -EPROBE_DEFER;
if (!IS_ERR(drv_data->clk))
clk_prepare_enable(drv_data->clk);
+ drv_data->axi_clk = devm_clk_get(&pd->dev, "axi");
+ if (IS_ERR(drv_data->axi_clk) &&
+ PTR_ERR(drv_data->axi_clk) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ if (!IS_ERR(drv_data->axi_clk))
+ clk_prepare_enable(drv_data->axi_clk);
+
drv_data->irq = platform_get_irq(pd, 0);
if (pdata) {
@@ -950,6 +958,7 @@ mv64xxx_i2c_probe(struct platform_device *pd)
exit_reset:
reset_control_assert(drv_data->rstc);
exit_clk:
+ clk_disable_unprepare(drv_data->axi_clk);
clk_disable_unprepare(drv_data->clk);
return rc;
@@ -963,6 +972,7 @@ mv64xxx_i2c_remove(struct platform_device *dev)
i2c_del_adapter(&drv_data->adapter);
free_irq(drv_data->irq, drv_data);
reset_control_assert(drv_data->rstc);
+ clk_disable_unprepare(drv_data->axi_clk);
clk_disable_unprepare(drv_data->clk);
return 0;
--
2.15.1
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH v2 2/2] i2c: mv64xxx: Fix clock resource by adding an optional bus clock
2018-01-10 17:07 ` Gregory CLEMENT
@ 2018-01-10 17:14 ` Thomas Petazzoni
-1 siblings, 0 replies; 12+ messages in thread
From: Thomas Petazzoni @ 2018-01-10 17:14 UTC (permalink / raw)
To: Gregory CLEMENT
Cc: Wolfram Sang, linux-i2c, Jason Cooper, Andrew Lunn,
Sebastian Hesselbarth, linux-arm-kernel, Antoine Tenart,
Miquèl Raynal, Nadav Haklai, Shadi Ammouri, Yehuda Yitschak,
Omri Itach, Hanna Hawa, Igal Liberman, Marcin Wojtas
Hello,
On Wed, 10 Jan 2018 18:07:43 +0100, Gregory CLEMENT wrote:
> On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
> is optional because not all the SoCs need them but at least for Armada
> 7K/8K it is actually mandatory.
>
> The binding documentation is updating accordingly.
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
> .../devicetree/bindings/i2c/i2c-mv64xxx.txt | 20 ++++++++++++++++++++
> drivers/i2c/busses/i2c-mv64xxx.c | 12 +++++++++++-
> 2 files changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> index 5c30026921ae..a835b724c738 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> @@ -25,6 +25,15 @@ default frequency is 100kHz
> whenever you're using the "allwinner,sun6i-a31-i2c"
> compatible.
>
> + - clocks: : pointers to the reference clocks for this device, the first
> + one is the one used for the clock on the i2c bus, the second
> + one is the clock used for the functional part of the
> + controller
> +
> + - clock-names : names of used clocks, mandatory if the second clock is
> + : used, the name must be "core", and "axi_clk" (the latter is
Spurious ":" at beginning of line. In addition, the name is "axi" not
"axi_clk", at least according to your code.
Best regards,
Thomas
--
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v2 2/2] i2c: mv64xxx: Fix clock resource by adding an optional bus clock
@ 2018-01-10 17:14 ` Thomas Petazzoni
0 siblings, 0 replies; 12+ messages in thread
From: Thomas Petazzoni @ 2018-01-10 17:14 UTC (permalink / raw)
To: linux-arm-kernel
Hello,
On Wed, 10 Jan 2018 18:07:43 +0100, Gregory CLEMENT wrote:
> On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
> is optional because not all the SoCs need them but at least for Armada
> 7K/8K it is actually mandatory.
>
> The binding documentation is updating accordingly.
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
> .../devicetree/bindings/i2c/i2c-mv64xxx.txt | 20 ++++++++++++++++++++
> drivers/i2c/busses/i2c-mv64xxx.c | 12 +++++++++++-
> 2 files changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> index 5c30026921ae..a835b724c738 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> @@ -25,6 +25,15 @@ default frequency is 100kHz
> whenever you're using the "allwinner,sun6i-a31-i2c"
> compatible.
>
> + - clocks: : pointers to the reference clocks for this device, the first
> + one is the one used for the clock on the i2c bus, the second
> + one is the clock used for the functional part of the
> + controller
> +
> + - clock-names : names of used clocks, mandatory if the second clock is
> + : used, the name must be "core", and "axi_clk" (the latter is
Spurious ":" at beginning of line. In addition, the name is "axi" not
"axi_clk", at least according to your code.
Best regards,
Thomas
--
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v2 2/2] i2c: mv64xxx: Fix clock resource by adding an optional bus clock
2018-01-10 17:07 ` Gregory CLEMENT
@ 2018-01-10 20:32 ` Andrew Lunn
-1 siblings, 0 replies; 12+ messages in thread
From: Andrew Lunn @ 2018-01-10 20:32 UTC (permalink / raw)
To: Gregory CLEMENT
Cc: Thomas Petazzoni, Yehuda Yitschak, Jason Cooper, Wolfram Sang,
Igal Liberman, Antoine Tenart, Omri Itach, Nadav Haklai,
Shadi Ammouri, linux-i2c, Miquèl Raynal, Marcin Wojtas,
Hanna Hawa, linux-arm-kernel, Sebastian Hesselbarth
On Wed, Jan 10, 2018 at 06:07:43PM +0100, Gregory CLEMENT wrote:
> On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
> is optional because not all the SoCs need them but at least for Armada
> 7K/8K it is actually mandatory.
>
> The binding documentation is updating accordingly.
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
> .../devicetree/bindings/i2c/i2c-mv64xxx.txt | 20 ++++++++++++++++++++
> drivers/i2c/busses/i2c-mv64xxx.c | 12 +++++++++++-
> 2 files changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> index 5c30026921ae..a835b724c738 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> @@ -25,6 +25,15 @@ default frequency is 100kHz
> whenever you're using the "allwinner,sun6i-a31-i2c"
> compatible.
>
> + - clocks: : pointers to the reference clocks for this device, the first
> + one is the one used for the clock on the i2c bus, the second
> + one is the clock used for the functional part of the
> + controller
> +
> + - clock-names : names of used clocks, mandatory if the second clock is
> + : used, the name must be "core", and "axi_clk" (the latter is
> + only for Armada 7K/8K).
Hi Gregory
Are these two clocks related?
Ethernet on Dove needs two clocks enabled.
static const struct clk_gating_soc_desc dove_gating_desc[] __initconst = {
{ "usb0", NULL, 0, 0 },
{ "usb1", NULL, 1, 0 },
{ "ge", "gephy", 2, 0 },
{ "sata", NULL, 3, 0 },
ge has a parent clock gephy. When you enable ge, the common clock code
walks up the tree of clocks, so will also turn on gephy.
Does this child/parent relationship exist with these i2c clocks?
Andrew
^ permalink raw reply [flat|nested] 12+ messages in thread* [PATCH v2 2/2] i2c: mv64xxx: Fix clock resource by adding an optional bus clock
@ 2018-01-10 20:32 ` Andrew Lunn
0 siblings, 0 replies; 12+ messages in thread
From: Andrew Lunn @ 2018-01-10 20:32 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Jan 10, 2018 at 06:07:43PM +0100, Gregory CLEMENT wrote:
> On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
> is optional because not all the SoCs need them but at least for Armada
> 7K/8K it is actually mandatory.
>
> The binding documentation is updating accordingly.
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
> .../devicetree/bindings/i2c/i2c-mv64xxx.txt | 20 ++++++++++++++++++++
> drivers/i2c/busses/i2c-mv64xxx.c | 12 +++++++++++-
> 2 files changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> index 5c30026921ae..a835b724c738 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> @@ -25,6 +25,15 @@ default frequency is 100kHz
> whenever you're using the "allwinner,sun6i-a31-i2c"
> compatible.
>
> + - clocks: : pointers to the reference clocks for this device, the first
> + one is the one used for the clock on the i2c bus, the second
> + one is the clock used for the functional part of the
> + controller
> +
> + - clock-names : names of used clocks, mandatory if the second clock is
> + : used, the name must be "core", and "axi_clk" (the latter is
> + only for Armada 7K/8K).
Hi Gregory
Are these two clocks related?
Ethernet on Dove needs two clocks enabled.
static const struct clk_gating_soc_desc dove_gating_desc[] __initconst = {
{ "usb0", NULL, 0, 0 },
{ "usb1", NULL, 1, 0 },
{ "ge", "gephy", 2, 0 },
{ "sata", NULL, 3, 0 },
ge has a parent clock gephy. When you enable ge, the common clock code
walks up the tree of clocks, so will also turn on gephy.
Does this child/parent relationship exist with these i2c clocks?
Andrew
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH v2 2/2] i2c: mv64xxx: Fix clock resource by adding an optional bus clock
2018-01-10 20:32 ` Andrew Lunn
@ 2018-01-11 8:16 ` Gregory CLEMENT
-1 siblings, 0 replies; 12+ messages in thread
From: Gregory CLEMENT @ 2018-01-11 8:16 UTC (permalink / raw)
To: Andrew Lunn
Cc: Wolfram Sang, linux-i2c, Jason Cooper, Sebastian Hesselbarth,
Thomas Petazzoni, linux-arm-kernel, Antoine Tenart,
Miquèl Raynal, Nadav Haklai, Shadi Ammouri, Yehuda Yitschak,
Omri Itach, Hanna Hawa, Igal Liberman, Marcin Wojtas
Hi Andrew,
On mer., janv. 10 2018, Andrew Lunn <andrew@lunn.ch> wrote:
> On Wed, Jan 10, 2018 at 06:07:43PM +0100, Gregory CLEMENT wrote:
>> On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
>> is optional because not all the SoCs need them but at least for Armada
>> 7K/8K it is actually mandatory.
>>
>> The binding documentation is updating accordingly.
>>
>> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
>> ---
>> .../devicetree/bindings/i2c/i2c-mv64xxx.txt | 20 ++++++++++++++++++++
>> drivers/i2c/busses/i2c-mv64xxx.c | 12 +++++++++++-
>> 2 files changed, 31 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
>> index 5c30026921ae..a835b724c738 100644
>> --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
>> +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
>> @@ -25,6 +25,15 @@ default frequency is 100kHz
>> whenever you're using the "allwinner,sun6i-a31-i2c"
>> compatible.
>>
>> + - clocks: : pointers to the reference clocks for this device, the first
>> + one is the one used for the clock on the i2c bus, the second
>> + one is the clock used for the functional part of the
>> + controller
>> +
>> + - clock-names : names of used clocks, mandatory if the second clock is
>> + : used, the name must be "core", and "axi_clk" (the latter is
>> + only for Armada 7K/8K).
>
> Hi Gregory
>
> Are these two clocks related?
>
> Ethernet on Dove needs two clocks enabled.
>
> static const struct clk_gating_soc_desc dove_gating_desc[] __initconst = {
> { "usb0", NULL, 0, 0 },
> { "usb1", NULL, 1, 0 },
> { "ge", "gephy", 2, 0 },
> { "sata", NULL, 3, 0 },
>
> ge has a parent clock gephy. When you enable ge, the common clock code
> walks up the tree of clocks, so will also turn on gephy.
>
> Does this child/parent relationship exist with these i2c clocks?
The child/parent relationship was the wrong assumption we made when we
wrote the clock driver for Armada 7K/8K. But now with more
documentation, it turned out that these 2 clocks are independant but
both are needed for i2c on Armada 7K/8K.
Gregory
>
> Andrew
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply [flat|nested] 12+ messages in thread* [PATCH v2 2/2] i2c: mv64xxx: Fix clock resource by adding an optional bus clock
@ 2018-01-11 8:16 ` Gregory CLEMENT
0 siblings, 0 replies; 12+ messages in thread
From: Gregory CLEMENT @ 2018-01-11 8:16 UTC (permalink / raw)
To: linux-arm-kernel
Hi Andrew,
On mer., janv. 10 2018, Andrew Lunn <andrew@lunn.ch> wrote:
> On Wed, Jan 10, 2018 at 06:07:43PM +0100, Gregory CLEMENT wrote:
>> On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
>> is optional because not all the SoCs need them but at least for Armada
>> 7K/8K it is actually mandatory.
>>
>> The binding documentation is updating accordingly.
>>
>> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
>> ---
>> .../devicetree/bindings/i2c/i2c-mv64xxx.txt | 20 ++++++++++++++++++++
>> drivers/i2c/busses/i2c-mv64xxx.c | 12 +++++++++++-
>> 2 files changed, 31 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
>> index 5c30026921ae..a835b724c738 100644
>> --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
>> +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
>> @@ -25,6 +25,15 @@ default frequency is 100kHz
>> whenever you're using the "allwinner,sun6i-a31-i2c"
>> compatible.
>>
>> + - clocks: : pointers to the reference clocks for this device, the first
>> + one is the one used for the clock on the i2c bus, the second
>> + one is the clock used for the functional part of the
>> + controller
>> +
>> + - clock-names : names of used clocks, mandatory if the second clock is
>> + : used, the name must be "core", and "axi_clk" (the latter is
>> + only for Armada 7K/8K).
>
> Hi Gregory
>
> Are these two clocks related?
>
> Ethernet on Dove needs two clocks enabled.
>
> static const struct clk_gating_soc_desc dove_gating_desc[] __initconst = {
> { "usb0", NULL, 0, 0 },
> { "usb1", NULL, 1, 0 },
> { "ge", "gephy", 2, 0 },
> { "sata", NULL, 3, 0 },
>
> ge has a parent clock gephy. When you enable ge, the common clock code
> walks up the tree of clocks, so will also turn on gephy.
>
> Does this child/parent relationship exist with these i2c clocks?
The child/parent relationship was the wrong assumption we made when we
wrote the clock driver for Armada 7K/8K. But now with more
documentation, it turned out that these 2 clocks are independant but
both are needed for i2c on Armada 7K/8K.
Gregory
>
> Andrew
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply [flat|nested] 12+ messages in thread