[PATCH v6 1/2] mtd: nand: sunxi: update DT bindings

[PATCH v6 1/2] mtd: nand: sunxi: update DT bindings

[Icenowy Zheng]

Document the reset lines

Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
---
Changes since v2:
  - Nothing.

 Documentation/devicetree/bindings/mtd/sunxi-nand.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/sunxi-nand.txt b/Documentation/devicetree/bindings/mtd/sunxi-nand.txt
index 086d6f4..a328fbb 100644
--- a/Documentation/devicetree/bindings/mtd/sunxi-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/sunxi-nand.txt
@@ -15,6 +15,8 @@ Optional children nodes:
 Children nodes represent the available nand chips.
 
 Optional properties:
+- reset : phandle + reset specifier pair
+- reset-names : must contain "ahb"
 - allwinner,rb : shall contain the native Ready/Busy ids.
  or
 - rb-gpios : shall contain the gpios used as R/B pins.
-- 
2.9.0

[PATCH v6 2/2] mtd: nand: sunxi: add reset line support

[Icenowy Zheng]

The NAND controller on some sun8i chips needs its reset line to be
deasserted before they can enter working state.

Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
---
  Changes in v2:
    - Corrected the error checking code of reset line.

  Changes in v3:
    - Corrected a more serious error brought in the "fix" of v2.

  Changes in v4:
    - Removed unneeded code block after "else".

  Changes in v5:
    - Added reassertion code in case of initialization error and device
      remove.

  Changes in v6:
    - Fixed a resource leak by not using goto to exit in case of error.

 drivers/mtd/nand/sunxi_nand.c | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index a83a690..08d5e88 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -39,6 +39,7 @@
 #include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/iopoll.h>
+#include <linux/reset.h>
 
 #define NFC_REG_CTL		0x0000
 #define NFC_REG_ST		0x0004
@@ -269,6 +270,7 @@ struct sunxi_nfc {
 	void __iomem *regs;
 	struct clk *ahb_clk;
 	struct clk *mod_clk;
+	struct reset_control *reset;
 	unsigned long assigned_cs;
 	unsigned long clk_rate;
 	struct list_head chips;
@@ -1871,26 +1873,42 @@ static int sunxi_nfc_probe(struct platform_device *pdev)
 	if (ret)
 		goto out_ahb_clk_unprepare;
 
+	nfc->reset = devm_reset_control_get_optional(dev, "ahb");
+
+	if (!IS_ERR(nfc->reset)) {
+		ret = reset_control_deassert(nfc->reset);
+		if (ret) {
+			dev_err(dev, "reset err %d\n", ret);
+			goto out_mod_clk_unprepare;
+		}
+	} else if (PTR_ERR(nfc->reset) != -ENOENT) {
+		ret = PTR_ERR(nfc->reset);
+		goto out_mod_clk_unprepare;
+	}
+
 	ret = sunxi_nfc_rst(nfc);
 	if (ret)
-		goto out_mod_clk_unprepare;
+		goto out_ahb_reset_reassert;
 
 	writel(0, nfc->regs + NFC_REG_INT);
 	ret = devm_request_irq(dev, irq, sunxi_nfc_interrupt,
 			       0, "sunxi-nand", nfc);
 	if (ret)
-		goto out_mod_clk_unprepare;
+		goto out_ahb_reset_reassert;
 
 	platform_set_drvdata(pdev, nfc);
 
 	ret = sunxi_nand_chips_init(dev, nfc);
 	if (ret) {
 		dev_err(dev, "failed to init nand chips\n");
-		goto out_mod_clk_unprepare;
+		goto out_ahb_reset_reassert;
 	}
 
 	return 0;
 
+out_ahb_reset_reassert:
+	if (!IS_ERR(nfc->reset))
+		reset_control_assert(nfc->reset);
 out_mod_clk_unprepare:
 	clk_disable_unprepare(nfc->mod_clk);
 out_ahb_clk_unprepare:
@@ -1904,6 +1922,10 @@ static int sunxi_nfc_remove(struct platform_device *pdev)
 	struct sunxi_nfc *nfc = platform_get_drvdata(pdev);
 
 	sunxi_nand_chips_cleanup(nfc);
+
+	if (!IS_ERR(nfc->reset))
+		reset_control_assert(nfc->reset);
+
 	clk_disable_unprepare(nfc->mod_clk);
 	clk_disable_unprepare(nfc->ahb_clk);
 
-- 
2.9.0

Re: [PATCH v6 2/2] mtd: nand: sunxi: add reset line support

[Maxime Ripard]

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On Mon, Jun 20, 2016 at 12:48:38PM +0800, Icenowy Zheng wrote:
> The NAND controller on some sun8i chips needs its reset line to be
> deasserted before they can enter working state.
> 
> Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>

Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Thanks,
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH v6 2/2] mtd: nand: sunxi: add reset line support

[Boris Brezillon]

On Mon, 20 Jun 2016 12:48:38 +0800
Icenowy Zheng <icenowy@aosc.xyz> wrote:

> The NAND controller on some sun8i chips needs its reset line to be
> deasserted before they can enter working state.
> 
> Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
> ---
>   Changes in v2:
>     - Corrected the error checking code of reset line.
> 
>   Changes in v3:
>     - Corrected a more serious error brought in the "fix" of v2.
> 
>   Changes in v4:
>     - Removed unneeded code block after "else".
> 
>   Changes in v5:
>     - Added reassertion code in case of initialization error and device
>       remove.
> 
>   Changes in v6:
>     - Fixed a resource leak by not using goto to exit in case of error.
> 
>  drivers/mtd/nand/sunxi_nand.c | 28 +++++++++++++++++++++++++---
>  1 file changed, 25 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
> index a83a690..08d5e88 100644
> --- a/drivers/mtd/nand/sunxi_nand.c
> +++ b/drivers/mtd/nand/sunxi_nand.c
> @@ -39,6 +39,7 @@
>  #include <linux/gpio.h>
>  #include <linux/interrupt.h>
>  #include <linux/iopoll.h>
> +#include <linux/reset.h>
>  
>  #define NFC_REG_CTL		0x0000
>  #define NFC_REG_ST		0x0004
> @@ -269,6 +270,7 @@ struct sunxi_nfc {
>  	void __iomem *regs;
>  	struct clk *ahb_clk;
>  	struct clk *mod_clk;
> +	struct reset_control *reset;
>  	unsigned long assigned_cs;
>  	unsigned long clk_rate;
>  	struct list_head chips;
> @@ -1871,26 +1873,42 @@ static int sunxi_nfc_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto out_ahb_clk_unprepare;
>  
> +	nfc->reset = devm_reset_control_get_optional(dev, "ahb");
> +
> +	if (!IS_ERR(nfc->reset)) {
> +		ret = reset_control_deassert(nfc->reset);
> +		if (ret) {
> +			dev_err(dev, "reset err %d\n", ret);
> +			goto out_mod_clk_unprepare;
> +		}
> +	} else if (PTR_ERR(nfc->reset) != -ENOENT) {
> +		ret = PTR_ERR(nfc->reset);

You should return -EDEFER_PROBE here.

And can you please rebase this series on top of nand/next [1]?

[1]https://github.com/linux-nand/linux/tree/nand/next

Re: [PATCH v6 2/2] mtd: nand: sunxi: add reset line support

[Icenowy Zheng]

In my opinion, return directly PTR_ERR(nfc->reset) is OK here.
If devm_reset_control_get_optional() return -EPROBE_DEFER, the code here will also return it. However, if we get other error, why should it return -EPROBE_DEFER again?

24.06.2016, 00:01, "Boris Brezillon" <boris.brezillon@free-electrons.com>:
> On Mon, 20 Jun 2016 12:48:38 +0800
> Icenowy Zheng <icenowy@aosc.xyz> wrote:
>
>>  The NAND controller on some sun8i chips needs its reset line to be
>>  deasserted before they can enter working state.
>>
>>  Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
>>  ---
>>    Changes in v2:
>>      - Corrected the error checking code of reset line.
>>
>>    Changes in v3:
>>      - Corrected a more serious error brought in the "fix" of v2.
>>
>>    Changes in v4:
>>      - Removed unneeded code block after "else".
>>
>>    Changes in v5:
>>      - Added reassertion code in case of initialization error and device
>>        remove.
>>
>>    Changes in v6:
>>      - Fixed a resource leak by not using goto to exit in case of error.
>>
>>   drivers/mtd/nand/sunxi_nand.c | 28 +++++++++++++++++++++++++---
>>   1 file changed, 25 insertions(+), 3 deletions(-)
>>
>>  diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
>>  index a83a690..08d5e88 100644
>>  --- a/drivers/mtd/nand/sunxi_nand.c
>>  +++ b/drivers/mtd/nand/sunxi_nand.c
>>  @@ -39,6 +39,7 @@
>>   #include <linux/gpio.h>
>>   #include <linux/interrupt.h>
>>   #include <linux/iopoll.h>
>>  +#include <linux/reset.h>
>>
>>   #define NFC_REG_CTL 0x0000
>>   #define NFC_REG_ST 0x0004
>>  @@ -269,6 +270,7 @@ struct sunxi_nfc {
>>           void __iomem *regs;
>>           struct clk *ahb_clk;
>>           struct clk *mod_clk;
>>  + struct reset_control *reset;
>>           unsigned long assigned_cs;
>>           unsigned long clk_rate;
>>           struct list_head chips;
>>  @@ -1871,26 +1873,42 @@ static int sunxi_nfc_probe(struct platform_device *pdev)
>>           if (ret)
>>                   goto out_ahb_clk_unprepare;
>>
>>  + nfc->reset = devm_reset_control_get_optional(dev, "ahb");
>>  +
>>  + if (!IS_ERR(nfc->reset)) {
>>  + ret = reset_control_deassert(nfc->reset);
>>  + if (ret) {
>>  + dev_err(dev, "reset err %d\n", ret);
>>  + goto out_mod_clk_unprepare;
>>  + }
>>  + } else if (PTR_ERR(nfc->reset) != -ENOENT) {
>>  + ret = PTR_ERR(nfc->reset);
>
> You should return -EDEFER_PROBE here.
>
> And can you please rebase this series on top of nand/next [1]?
>
> [1]https://github.com/linux-nand/linux/tree/nand/next

Re: [PATCH v6 2/2] mtd: nand: sunxi: add reset line support

[Boris Brezillon]

On Fri, 24 Jun 2016 07:20:38 +0800
Icenowy Zheng <icenowy@aosc.xyz> wrote:

> In my opinion, return directly PTR_ERR(nfc->reset) is OK here.
> If devm_reset_control_get_optional() return -EPROBE_DEFER, the code here will also return it. However, if we get other error, why should it return -EPROBE_DEFER again?

Sorry, I just had a brainfart :-). Your implementation is correct.
BTW, can you avoid top-posting and reply inline?

> 
> 24.06.2016, 00:01, "Boris Brezillon" <boris.brezillon@free-electrons.com>:
> > On Mon, 20 Jun 2016 12:48:38 +0800
> > Icenowy Zheng <icenowy@aosc.xyz> wrote:
> >  
> >>  The NAND controller on some sun8i chips needs its reset line to be
> >>  deasserted before they can enter working state.
> >>
> >>  Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
> >>  ---
> >>    Changes in v2:
> >>      - Corrected the error checking code of reset line.
> >>
> >>    Changes in v3:
> >>      - Corrected a more serious error brought in the "fix" of v2.
> >>
> >>    Changes in v4:
> >>      - Removed unneeded code block after "else".
> >>
> >>    Changes in v5:
> >>      - Added reassertion code in case of initialization error and device
> >>        remove.
> >>
> >>    Changes in v6:
> >>      - Fixed a resource leak by not using goto to exit in case of error.
> >>
> >>   drivers/mtd/nand/sunxi_nand.c | 28 +++++++++++++++++++++++++---
> >>   1 file changed, 25 insertions(+), 3 deletions(-)
> >>
> >>  diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
> >>  index a83a690..08d5e88 100644
> >>  --- a/drivers/mtd/nand/sunxi_nand.c
> >>  +++ b/drivers/mtd/nand/sunxi_nand.c
> >>  @@ -39,6 +39,7 @@
> >>   #include <linux/gpio.h>
> >>   #include <linux/interrupt.h>
> >>   #include <linux/iopoll.h>
> >>  +#include <linux/reset.h>
> >>
> >>   #define NFC_REG_CTL 0x0000
> >>   #define NFC_REG_ST 0x0004
> >>  @@ -269,6 +270,7 @@ struct sunxi_nfc {
> >>           void __iomem *regs;
> >>           struct clk *ahb_clk;
> >>           struct clk *mod_clk;
> >>  + struct reset_control *reset;
> >>           unsigned long assigned_cs;
> >>           unsigned long clk_rate;
> >>           struct list_head chips;
> >>  @@ -1871,26 +1873,42 @@ static int sunxi_nfc_probe(struct platform_device *pdev)
> >>           if (ret)
> >>                   goto out_ahb_clk_unprepare;
> >>
> >>  + nfc->reset = devm_reset_control_get_optional(dev, "ahb");
> >>  +
> >>  + if (!IS_ERR(nfc->reset)) {
> >>  + ret = reset_control_deassert(nfc->reset);
> >>  + if (ret) {
> >>  + dev_err(dev, "reset err %d\n", ret);
> >>  + goto out_mod_clk_unprepare;
> >>  + }
> >>  + } else if (PTR_ERR(nfc->reset) != -ENOENT) {
> >>  + ret = PTR_ERR(nfc->reset);  
> >
> > You should return -EDEFER_PROBE here.
> >
> > And can you please rebase this series on top of nand/next [1]?
> >
> > [1]https://github.com/linux-nand/linux/tree/nand/next  

Re: [PATCH v6 1/2] mtd: nand: sunxi: update DT bindings

[Maxime Ripard]

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On Mon, Jun 20, 2016 at 12:48:37PM +0800, Icenowy Zheng wrote:
> Document the reset lines
> 
> Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>

Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Thanks,
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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