[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 at free-electrons.com>:
> On Mon, 20 Jun 2016 12:48:38 +0800
> Icenowy Zheng <icenowy at 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 at 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