diff mbox

i2c: designware: add reset interface

Message ID 1479789700-19532-1-git-send-email-zhangfei.gao@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Zhangfei Gao Nov. 22, 2016, 4:41 a.m. UTC 
Some platforms like hi3660 need do reset first to allow accessing registers

Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
---
 drivers/i2c/busses/i2c-designware-core.h    | 1 +
 drivers/i2c/busses/i2c-designware-platdrv.c | 5 +++++
 2 files changed, 6 insertions(+)

Comments

Wolfram Sang Dec. 13, 2016, 8:34 p.m. UTC | #1 
On Tue, Nov 22, 2016 at 12:41:40PM +0800, Zhangfei Gao wrote:
> Some platforms like hi3660 need do reset first to allow accessing registers
> 
> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>

Adding designware maintainers to CC...

> ---
>  drivers/i2c/busses/i2c-designware-core.h    | 1 +
>  drivers/i2c/busses/i2c-designware-platdrv.c | 5 +++++
>  2 files changed, 6 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
> index 0d44d2a..94b14fa 100644
> --- a/drivers/i2c/busses/i2c-designware-core.h
> +++ b/drivers/i2c/busses/i2c-designware-core.h
> @@ -80,6 +80,7 @@ struct dw_i2c_dev {
>  	void __iomem		*base;
>  	struct completion	cmd_complete;
>  	struct clk		*clk;
> +	struct reset_control	*rst;
>  	u32			(*get_clk_rate_khz) (struct dw_i2c_dev *dev);
>  	struct dw_pci_controller *controller;
>  	int			cmd_err;
> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
> index 0b42a12..fd80e58 100644
> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
> @@ -38,6 +38,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/property.h>
>  #include <linux/io.h>
> +#include <linux/reset.h>
>  #include <linux/slab.h>
>  #include <linux/acpi.h>
>  #include <linux/platform_data/i2c-designware.h>
> @@ -176,6 +177,10 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
>  	dev->irq = irq;
>  	platform_set_drvdata(pdev, dev);
>  
> +	dev->rst = devm_reset_control_get(&pdev->dev, NULL);
> +	if (!IS_ERR(dev->rst))
> +		reset_control_reset(dev->rst);
> +
>  	/* fast mode by default because of legacy reasons */
>  	dev->clk_freq = 400000;
>  
> -- 
> 2.7.4
>
Andy Shevchenko Dec. 14, 2016, 7 p.m. UTC | #2 
On Tue, 2016-12-13 at 21:34 +0100, Wolfram Sang wrote:
> On Tue, Nov 22, 2016 at 12:41:40PM +0800, Zhangfei Gao wrote:
> > Some platforms like hi3660 need do reset first to allow accessing
> > registers
> > 
> > Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
> 
> Adding designware maintainers to CC...
> 
> > ---
> >  drivers/i2c/busses/i2c-designware-core.h    | 1 +
> >  drivers/i2c/busses/i2c-designware-platdrv.c | 5 +++++
> >  2 files changed, 6 insertions(+)
> > 
> > diff --git a/drivers/i2c/busses/i2c-designware-core.h
> > b/drivers/i2c/busses/i2c-designware-core.h
> > index 0d44d2a..94b14fa 100644
> > --- a/drivers/i2c/busses/i2c-designware-core.h
> > +++ b/drivers/i2c/busses/i2c-designware-core.h
> > @@ -80,6 +80,7 @@ struct dw_i2c_dev {
> >  	void __iomem		*base;
> >  	struct completion	cmd_complete;
> >  	struct clk		*clk;
> > +	struct reset_control	*rst;
> >  	u32			(*get_clk_rate_khz) (struct
> > dw_i2c_dev *dev);
> >  	struct dw_pci_controller *controller;
> >  	int			cmd_err;
> > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c
> > b/drivers/i2c/busses/i2c-designware-platdrv.c
> > index 0b42a12..fd80e58 100644
> > --- a/drivers/i2c/busses/i2c-designware-platdrv.c
> > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
> > @@ -38,6 +38,7 @@
> >  #include <linux/pm_runtime.h>
> >  #include <linux/property.h>
> >  #include <linux/io.h>
> > +#include <linux/reset.h>
> >  #include <linux/slab.h>
> >  #include <linux/acpi.h>
> >  #include <linux/platform_data/i2c-designware.h>
> > @@ -176,6 +177,10 @@ static int dw_i2c_plat_probe(struct
> > platform_device *pdev)
> >  	dev->irq = irq;
> >  	platform_set_drvdata(pdev, dev);
> >  
> > +	dev->rst = devm_reset_control_get(&pdev->dev, NULL);
> > +	if (!IS_ERR(dev->rst))
> > +		reset_control_reset(dev->rst);

Do we care about EPROBE_DEFER?

Perhaps on error path we need to assert it.

And I guess it should be devm_reset_control_get_optional().

> > +
> >  	/* fast mode by default because of legacy reasons */
> >  	dev->clk_freq = 400000;
> >  
> > -- 
> > 2.7.4
> >
Zhangfei Gao Dec. 15, 2016, 8:56 a.m. UTC | #3 
On 2016年12月15日 03:00, Andy Shevchenko wrote:
> On Tue, 2016-12-13 at 21:34 +0100, Wolfram Sang wrote:
>> On Tue, Nov 22, 2016 at 12:41:40PM +0800, Zhangfei Gao wrote:
>>> Some platforms like hi3660 need do reset first to allow accessing
>>> registers
>>>
>>> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
>> Adding designware maintainers to CC...
>>
>>> ---
>>>   drivers/i2c/busses/i2c-designware-core.h    | 1 +
>>>   drivers/i2c/busses/i2c-designware-platdrv.c | 5 +++++
>>>   2 files changed, 6 insertions(+)
>>>
>>> diff --git a/drivers/i2c/busses/i2c-designware-core.h
>>> b/drivers/i2c/busses/i2c-designware-core.h
>>> index 0d44d2a..94b14fa 100644
>>> --- a/drivers/i2c/busses/i2c-designware-core.h
>>> +++ b/drivers/i2c/busses/i2c-designware-core.h
>>> @@ -80,6 +80,7 @@ struct dw_i2c_dev {
>>>   	void __iomem		*base;
>>>   	struct completion	cmd_complete;
>>>   	struct clk		*clk;
>>> +	struct reset_control	*rst;
>>>   	u32			(*get_clk_rate_khz) (struct
>>> dw_i2c_dev *dev);
>>>   	struct dw_pci_controller *controller;
>>>   	int			cmd_err;
>>> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c
>>> b/drivers/i2c/busses/i2c-designware-platdrv.c
>>> index 0b42a12..fd80e58 100644
>>> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
>>> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
>>> @@ -38,6 +38,7 @@
>>>   #include <linux/pm_runtime.h>
>>>   #include <linux/property.h>
>>>   #include <linux/io.h>
>>> +#include <linux/reset.h>
>>>   #include <linux/slab.h>
>>>   #include <linux/acpi.h>
>>>   #include <linux/platform_data/i2c-designware.h>
>>> @@ -176,6 +177,10 @@ static int dw_i2c_plat_probe(struct
>>> platform_device *pdev)
>>>   	dev->irq = irq;
>>>   	platform_set_drvdata(pdev, dev);
>>>   
>>> +	dev->rst = devm_reset_control_get(&pdev->dev, NULL);
>>> +	if (!IS_ERR(dev->rst))
>>> +		reset_control_reset(dev->rst);
> Do we care about EPROBE_DEFER?
>
> Perhaps on error path we need to assert it.
>
> And I guess it should be devm_reset_control_get_optional().

Thanks Andy
Good suggestion, will update accordingly.

Thanks
diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 0d44d2a..94b14fa 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -80,6 +80,7 @@  struct dw_i2c_dev {
 	void __iomem		*base;
 	struct completion	cmd_complete;
 	struct clk		*clk;
+	struct reset_control	*rst;
 	u32			(*get_clk_rate_khz) (struct dw_i2c_dev *dev);
 	struct dw_pci_controller *controller;
 	int			cmd_err;
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 0b42a12..fd80e58 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -38,6 +38,7 @@ 
 #include <linux/pm_runtime.h>
 #include <linux/property.h>
 #include <linux/io.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <linux/platform_data/i2c-designware.h>
@@ -176,6 +177,10 @@  static int dw_i2c_plat_probe(struct platform_device *pdev)
 	dev->irq = irq;
 	platform_set_drvdata(pdev, dev);
 
+	dev->rst = devm_reset_control_get(&pdev->dev, NULL);
+	if (!IS_ERR(dev->rst))
+		reset_control_reset(dev->rst);
+
 	/* fast mode by default because of legacy reasons */
 	dev->clk_freq = 400000;