* [PATCH v2] serial: 8250_of: Add reset support
@ 2017-05-26 1:55 Joel Stanley
2017-05-29 9:43 ` Philipp Zabel
0 siblings, 1 reply; 3+ messages in thread
From: Joel Stanley @ 2017-05-26 1:55 UTC (permalink / raw)
To: Greg Kroah-Hartman, Rob Herring, Mark Rutland, Philipp Zabel
Cc: linux-serial, devicetree, linux-kernel
This adds the hooks for an optional reset controller in the 8250 device
tree node.
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
v2:
Address Philipp's comments. Thanks for the review!
- use _shared variant
- remove unnecessary error handling
Documentation/devicetree/bindings/serial/8250.txt | 1 +
drivers/tty/serial/8250/8250_of.c | 10 ++++++++++
2 files changed, 11 insertions(+)
diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt
index 10276a46ecef..63e32393f82b 100644
--- a/Documentation/devicetree/bindings/serial/8250.txt
+++ b/Documentation/devicetree/bindings/serial/8250.txt
@@ -45,6 +45,7 @@ Optional properties:
property.
- tx-threshold: Specify the TX FIFO low water indication for parts with
programmable TX FIFO thresholds.
+- resets : phandle + reset specifier pairs
Note:
* fsl,ns16550:
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 1cbadafc6889..e95cc9698c32 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -19,11 +19,13 @@
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/clk.h>
+#include <linux/reset.h>
#include "8250.h"
struct of_serial_info {
struct clk *clk;
+ struct reset_control *rst;
int type;
int line;
};
@@ -132,6 +134,13 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
}
}
+ info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL);
+ if (IS_ERR(info->rst))
+ goto out;
+ ret = reset_control_deassert(info->rst);
+ if (ret)
+ goto out;
+
port->type = type;
port->uartclk = clk;
port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
@@ -231,6 +240,7 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
if (info->clk)
clk_disable_unprepare(info->clk);
+ reset_control_assert(info->rst);
kfree(info);
return 0;
}
--
2.11.0
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v2] serial: 8250_of: Add reset support
2017-05-26 1:55 [PATCH v2] serial: 8250_of: Add reset support Joel Stanley
@ 2017-05-29 9:43 ` Philipp Zabel
2017-05-29 9:57 ` Joel Stanley
0 siblings, 1 reply; 3+ messages in thread
From: Philipp Zabel @ 2017-05-29 9:43 UTC (permalink / raw)
To: Joel Stanley
Cc: Greg Kroah-Hartman, Rob Herring, Mark Rutland, linux-serial,
devicetree, linux-kernel
Hi Joel,
On Fri, 2017-05-26 at 11:55 +1000, Joel Stanley wrote:
> This adds the hooks for an optional reset controller in the 8250 device
> tree node.
>
> Signed-off-by: Joel Stanley <joel@jms.id.au>
>
> ---
> v2:
> Address Philipp's comments. Thanks for the review!
> - use _shared variant
> - remove unnecessary error handling
>
> Documentation/devicetree/bindings/serial/8250.txt | 1 +
> drivers/tty/serial/8250/8250_of.c | 10 ++++++++++
> 2 files changed, 11 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt
> index 10276a46ecef..63e32393f82b 100644
> --- a/Documentation/devicetree/bindings/serial/8250.txt
> +++ b/Documentation/devicetree/bindings/serial/8250.txt
> @@ -45,6 +45,7 @@ Optional properties:
> property.
> - tx-threshold: Specify the TX FIFO low water indication for parts with
> programmable TX FIFO thresholds.
> +- resets : phandle + reset specifier pairs
>
> Note:
> * fsl,ns16550:
> diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
> index 1cbadafc6889..e95cc9698c32 100644
> --- a/drivers/tty/serial/8250/8250_of.c
> +++ b/drivers/tty/serial/8250/8250_of.c
> @@ -19,11 +19,13 @@
> #include <linux/of_irq.h>
> #include <linux/of_platform.h>
> #include <linux/clk.h>
> +#include <linux/reset.h>
>
> #include "8250.h"
>
> struct of_serial_info {
> struct clk *clk;
> + struct reset_control *rst;
> int type;
> int line;
> };
> @@ -132,6 +134,13 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
> }
> }
>
> + info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL);
> + if (IS_ERR(info->rst))
> + goto out;
> + ret = reset_control_deassert(info->rst);
> + if (ret)
> + goto out;
> +
> port->type = type;
> port->uartclk = clk;
> port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
> @@ -231,6 +240,7 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
>
> if (info->clk)
> clk_disable_unprepare(info->clk);
> + reset_control_assert(info->rst);
The clock is enabled before the reset is deasserted in
of_platform_serial_setup, I'd disable it after asserting the reset in
of_platform_serial_remove. Other than that,
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
regards
Philipp
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v2] serial: 8250_of: Add reset support
2017-05-29 9:43 ` Philipp Zabel
@ 2017-05-29 9:57 ` Joel Stanley
0 siblings, 0 replies; 3+ messages in thread
From: Joel Stanley @ 2017-05-29 9:57 UTC (permalink / raw)
To: Philipp Zabel
Cc: Greg Kroah-Hartman, Rob Herring, Mark Rutland, linux-serial,
devicetree, Linux Kernel Mailing List
On Mon, May 29, 2017 at 7:13 PM, Philipp Zabel <p.zabel@pengutronix.de> wrote:
> Hi Joel,
>
> On Fri, 2017-05-26 at 11:55 +1000, Joel Stanley wrote:
>> This adds the hooks for an optional reset controller in the 8250 device
>> tree node.
>>
>> Signed-off-by: Joel Stanley <joel@jms.id.au>
>>
>> ---
>> v2:
>> Address Philipp's comments. Thanks for the review!
>> - use _shared variant
>> - remove unnecessary error handling
>>
>> Documentation/devicetree/bindings/serial/8250.txt | 1 +
>> drivers/tty/serial/8250/8250_of.c | 10 ++++++++++
>> 2 files changed, 11 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt
>> index 10276a46ecef..63e32393f82b 100644
>> --- a/Documentation/devicetree/bindings/serial/8250.txt
>> +++ b/Documentation/devicetree/bindings/serial/8250.txt
>> @@ -45,6 +45,7 @@ Optional properties:
>> property.
>> - tx-threshold: Specify the TX FIFO low water indication for parts with
>> programmable TX FIFO thresholds.
>> +- resets : phandle + reset specifier pairs
>>
>> Note:
>> * fsl,ns16550:
>> diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
>> index 1cbadafc6889..e95cc9698c32 100644
>> --- a/drivers/tty/serial/8250/8250_of.c
>> +++ b/drivers/tty/serial/8250/8250_of.c
>> @@ -19,11 +19,13 @@
>> #include <linux/of_irq.h>
>> #include <linux/of_platform.h>
>> #include <linux/clk.h>
>> +#include <linux/reset.h>
>>
>> #include "8250.h"
>>
>> struct of_serial_info {
>> struct clk *clk;
>> + struct reset_control *rst;
>> int type;
>> int line;
>> };
>> @@ -132,6 +134,13 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
>> }
>> }
>>
>> + info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL);
>> + if (IS_ERR(info->rst))
>> + goto out;
>> + ret = reset_control_deassert(info->rst);
>> + if (ret)
>> + goto out;
>> +
>> port->type = type;
>> port->uartclk = clk;
>> port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
>> @@ -231,6 +240,7 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
>>
>> if (info->clk)
>> clk_disable_unprepare(info->clk);
>> + reset_control_assert(info->rst);
>
> The clock is enabled before the reset is deasserted in
> of_platform_serial_setup, I'd disable it after asserting the reset in
> of_platform_serial_remove. Other than that,
>
> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Doh, I'll send a v3 with your reviewed-by attached.
Thanks!
Joel
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-05-29 9:57 ` Joel Stanley
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