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

From: Boris Brezillon
Date: Thu Jun 23 2016 - 12:04:27 EST


On Mon, 20 Jun 2016 12:48:38 +0800
Icenowy Zheng <icenowy@xxxxxxxx> 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@xxxxxxxx>
> ---
> ÂChanges in v2:
> ÂÂÂ- Corrected the error checking code of reset line.
>
> ÂChanges in v3:
> ÂÂÂ- Corrected a more serious error brought in the "fix" of v2.
>
> ÂChanges in v4:
> ÂÂÂ- Removed unneeded code block after "else".
>
> ÂChanges in v5:
> ÂÂÂ- Added reassertion code in case of initialization error and device
> ÂÂÂÂÂremove.
>
> 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