Patchwork [v4,2/2] i2c: designware: add two optional property tx/rx-fifo-size

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Submitter Zhangfei Gao
Date July 26, 2013, 1:22 p.m.
Message ID <1374844938-25505-3-git-send-email-zhangfei.gao@linaro.org>
Download mbox | patch
Permalink /patch/262159/
State Superseded
Headers show

Comments

Zhangfei Gao - July 26, 2013, 1:22 p.m.
Some platform can not get fifo-size info form register DW_IC_COMP_PARAM_1.
Give chance to update rx-fifo-size and tx-fifo-size if provided in dts.

Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Acked-by: Baruch Siach <baruch@tkos.co.il>
---
 .../devicetree/bindings/i2c/i2c-designware.txt     |    7 +++++++
 drivers/i2c/busses/i2c-designware-platdrv.c        |    3 +++
 2 files changed, 10 insertions(+)
Mark Rutland - Aug. 10, 2013, 12:50 p.m.
On Fri, Jul 26, 2013 at 02:22:18PM +0100, Zhangfei Gao wrote:
> Some platform can not get fifo-size info form register DW_IC_COMP_PARAM_1.

s/form/from/

Why can they not get info from the register? Is it not implemented, or
buggy? It would be nice to mention why.

> Give chance to update rx-fifo-size and tx-fifo-size if provided in dts.
> 
> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
> Acked-by: Baruch Siach <baruch@tkos.co.il>
> ---
>  .../devicetree/bindings/i2c/i2c-designware.txt     |    7 +++++++
>  drivers/i2c/busses/i2c-designware-platdrv.c        |    3 +++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
> index 7fd7fa2..af0bf8f 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
> @@ -6,6 +6,11 @@ Required properties :
>   - reg : Offset and length of the register set for the device
>   - interrupts : <IRQ> where IRQ is the interrupt number.
>  
> +Optional properties:
> +
> + - rx-fifo-size : 1 cell, Rx fifo size
> + - tx-fifo-size : 1 cell, Tx fifo size

Units? I assume these are in bytes?

It would be nice to mention in the bidning when you need these
properties (i.e. only hwen you can't figure it out from
DW_IC_COMP_PARAM_1 becase ________.

Thanks,
Mark.
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zhangfei gao - Aug. 11, 2013, 7:29 a.m.
On Sat, Aug 10, 2013 at 8:50 PM, Mark Rutland <mark.rutland@arm.com> wrote:
> On Fri, Jul 26, 2013 at 02:22:18PM +0100, Zhangfei Gao wrote:
>> Some platform can not get fifo-size info form register DW_IC_COMP_PARAM_1.
>
> s/form/from/
>
> Why can they not get info from the register? Is it not implemented, or
> buggy? It would be nice to mention why.

Dear Mark

Thanks for asking me such question.
When trying to answer this question, I find this patch is not needed now.
It should be caused by my mistake.

Really appreciated.

>
>> Give chance to update rx-fifo-size and tx-fifo-size if provided in dts.
>>
>> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
>> Acked-by: Baruch Siach <baruch@tkos.co.il>
>> ---
>>  .../devicetree/bindings/i2c/i2c-designware.txt     |    7 +++++++
>>  drivers/i2c/busses/i2c-designware-platdrv.c        |    3 +++
>>  2 files changed, 10 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
>> index 7fd7fa2..af0bf8f 100644
>> --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt
>> +++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
>> @@ -6,6 +6,11 @@ Required properties :
>>   - reg : Offset and length of the register set for the device
>>   - interrupts : <IRQ> where IRQ is the interrupt number.
>>
>> +Optional properties:
>> +
>> + - rx-fifo-size : 1 cell, Rx fifo size
>> + - tx-fifo-size : 1 cell, Tx fifo size
>
> Units? I assume these are in bytes?
>
> It would be nice to mention in the bidning when you need these
> properties (i.e. only hwen you can't figure it out from
> DW_IC_COMP_PARAM_1 becase ________.
>
> Thanks,
> Mark.
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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Patch

diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
index 7fd7fa2..af0bf8f 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
@@ -6,6 +6,11 @@  Required properties :
  - reg : Offset and length of the register set for the device
  - interrupts : <IRQ> where IRQ is the interrupt number.
 
+Optional properties:
+
+ - rx-fifo-size : 1 cell, Rx fifo size
+ - tx-fifo-size : 1 cell, Tx fifo size
+
 Recommended properties :
 
  - clock-frequency : desired I2C bus clock frequency in Hz.
@@ -22,6 +27,8 @@  Example :
 		compatible = "snps,designware-i2c";
 		reg = <0xf0000 0x1000>;
 		interrupts = <11>;
+		rx-fifo-size = <16>;
+		tx-fifo-size = <16>;
 		clock-frequency = <400000>;
 	};
 
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 36ceebc..f657e65 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -86,6 +86,7 @@  static int dw_i2c_probe(struct platform_device *pdev)
 	struct dw_i2c_dev *dev;
 	struct i2c_adapter *adap;
 	struct resource *mem;
+	struct device_node *np = pdev->dev.of_node;
 	int irq, r;
 
 	irq = platform_get_irq(pdev, 0);
@@ -145,6 +146,8 @@  static int dw_i2c_probe(struct platform_device *pdev)
 		dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 		dev->adapter.nr = pdev->id;
 	}
+	of_property_read_u32(np, "rx-fifo-size", &dev->rx_fifo_depth);
+	of_property_read_u32(np, "tx-fifo-size", &dev->tx_fifo_depth);
 	r = i2c_dw_init(dev);
 	if (r)
 		return r;