[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

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

[Maxime Ripard]

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

[Maxime Ripard]

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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[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

[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

[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