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mtd: rawnand: sunxi: Remove support for GPIO-based Ready/Busy polling

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None of the existing platforms connect the R/B pin to a GPIO (they all
use one of the dedicated R/B pin).
Anyway, if we ever get short of native R/B pins, it's probably better
to fallback to STATUS reg polling than trying to poll a GPIO.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
This commit is contained in:
Boris Brezillon 2018-03-27 09:06:14 +02:00
parent 290450dddb
commit ddd5ed3a90
2 changed files with 15 additions and 78 deletions
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2
Documentation/devicetree/bindings/mtd/sunxi-nand.txt
View File

@ -22,8 +22,6 @@ 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.
- nand-ecc-mode : one of the supported ECC modes ("hw", "soft", "soft_bch" or
"none")

91
drivers/mtd/nand/raw/sunxi_nand.c
View File

@ -165,49 +165,16 @@
#define NFC_MAX_CS 7
/*
* Ready/Busy detection type: describes the Ready/Busy detection modes
*
* @RB_NONE: no external detection available, rely on STATUS command
* and software timeouts
* @RB_NATIVE: use sunxi NAND controller Ready/Busy support. The Ready/Busy
* pin of the NAND flash chip must be connected to one of the
* native NAND R/B pins (those which can be muxed to the NAND
* Controller)
* @RB_GPIO: use a simple GPIO to handle Ready/Busy status. The Ready/Busy
* pin of the NAND flash chip must be connected to a GPIO capable
* pin.
*/
enum sunxi_nand_rb_type {
RB_NONE,
RB_NATIVE,
RB_GPIO,
};
/*
* Ready/Busy structure: stores information related to Ready/Busy detection
*
* @type: the Ready/Busy detection mode
* @info: information related to the R/B detection mode. Either a gpio
* id or a native R/B id (those supported by the NAND controller).
*/
struct sunxi_nand_rb {
enum sunxi_nand_rb_type type;
union {
int gpio;
int nativeid;
} info;
};
/*
* Chip Select structure: stores information related to NAND Chip Select
*
* @cs: the NAND CS id used to communicate with a NAND Chip
* @rb: the Ready/Busy description
* @rb: the Ready/Busy pin ID. -1 means no R/B pin connected to the
* NFC
*/
struct sunxi_nand_chip_sel {
u8 cs;
struct sunxi_nand_rb rb;
s8 rb;
};
/*
@ -440,30 +407,19 @@ static int sunxi_nfc_dev_ready(struct mtd_info *mtd)
struct nand_chip *nand = mtd_to_nand(mtd);
struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
struct sunxi_nand_rb *rb;
int ret;
u32 mask;
if (sunxi_nand->selected < 0)
return 0;
rb = &sunxi_nand->sels[sunxi_nand->selected].rb;
switch (rb->type) {
case RB_NATIVE:
ret = !!(readl(nfc->regs + NFC_REG_ST) &
NFC_RB_STATE(rb->info.nativeid));
break;
case RB_GPIO:
ret = gpio_get_value(rb->info.gpio);
break;
case RB_NONE:
default:
ret = 0;
if (sunxi_nand->sels[sunxi_nand->selected].rb < 0) {
dev_err(nfc->dev, "cannot check R/B NAND status!\n");
break;
return 0;
}
return ret;
mask = NFC_RB_STATE(sunxi_nand->sels[sunxi_nand->selected].rb);
return !!(readl(nfc->regs + NFC_REG_ST) & mask);
}
static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip)
@ -488,12 +444,11 @@ static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip)
ctl |= NFC_CE_SEL(sel->cs) | NFC_EN |
NFC_PAGE_SHIFT(nand->page_shift);
if (sel->rb.type == RB_NONE) {
if (sel->rb < 0) {
nand->dev_ready = NULL;
} else {
nand->dev_ready = sunxi_nfc_dev_ready;
if (sel->rb.type == RB_NATIVE)
ctl |= NFC_RB_SEL(sel->rb.info.nativeid);
ctl |= NFC_RB_SEL(sel->rb);
}
writel(mtd->writesize, nfc->regs + NFC_REG_SPARE_AREA);
@ -1946,26 +1901,10 @@ static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc,
chip->sels[i].cs = tmp;
if (!of_property_read_u32_index(np, "allwinner,rb", i, &tmp) &&
tmp < 2) {
chip->sels[i].rb.type = RB_NATIVE;
chip->sels[i].rb.info.nativeid = tmp;
} else {
ret = of_get_named_gpio(np, "rb-gpios", i);
if (ret >= 0) {
tmp = ret;
chip->sels[i].rb.type = RB_GPIO;
chip->sels[i].rb.info.gpio = tmp;
ret = devm_gpio_request(dev, tmp, "nand-rb");
if (ret)
return ret;
ret = gpio_direction_input(tmp);
if (ret)
return ret;
} else {
chip->sels[i].rb.type = RB_NONE;
}
}
tmp < 2)
chip->sels[i].rb = tmp;
else
chip->sels[i].rb = -1;
}
nand = &chip->nand;