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

On Fri, 24 Jun 2016 07:20:38 +0800
Icenowy Zheng [off-list ref] 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" [off-list ref]:

quoted

On Mon, 20 Jun 2016 12:48:38 +0800
Icenowy Zheng [off-list ref] wrote:
 

quoted

?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 [off-list ref]
?---
???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