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mtd: nand: omap2: Implement NAND ready using gpiolib 

The GPMC WAIT pin status are now available over gpiolib.
Update the omap_dev_ready() function to use gpio instead of
directly accessing GPMC register space.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Tony Lindgren <tony@atomide.com>
This commit is contained in:
Roger Quadros 2015-08-06 17:39:35 +03:00
parent 9e6946215d
commit 10f22ee367
3 changed files with 21 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/devicetree/bindings/mtd/gpmc-nand.txt
View File

@ -48,6 +48,7 @@ Optional properties:
locating ECC errors for BCHx algorithms. SoC devices which have
ELM hardware engines should specify this device node in .dtsi
Using ELM for ECC error correction frees some CPU cycles.
- rb-gpios: GPIO specifier for the ready/busy# pin.
For inline partition table parsing (optional):
@ -78,6 +79,7 @@ Example for an AM33xx board:
nand-bus-width = <16>;
ti,nand-ecc-opt = "bch8";
ti,nand-xfer-type = "polled";
rb-gpios = <&gpmc 0 GPIO_ACTIVE_HIGH>; /* gpmc_wait0 */
gpmc,sync-clk-ps = <0>;
gpmc,cs-on-ns = <0>;

29
drivers/mtd/nand/omap2.c
View File

@ -12,6 +12,7 @@
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
@ -182,6 +183,8 @@ struct omap_nand_info {
struct nand_ecclayout oobinfo;
/* fields specific for BCHx_HW ECC scheme */
struct device *elm_dev;
/* NAND ready gpio */
struct gpio_desc *ready_gpiod;
};
static inline struct omap_nand_info *mtd_to_omap(struct mtd_info *mtd)
@ -1023,21 +1026,16 @@ static int omap_wait(struct mtd_info *mtd, struct nand_chip *chip)
}
/**
* omap_dev_ready - calls the platform specific dev_ready function
* omap_dev_ready - checks the NAND Ready GPIO line
* @mtd: MTD device structure
*
* Returns true if ready and false if busy.
*/
static int omap_dev_ready(struct mtd_info *mtd)
{
unsigned int val = 0;
struct omap_nand_info *info = mtd_to_omap(mtd);
val = readl(info->reg.gpmc_status);
if ((val & 0x100) == 0x100) {
return 1;
} else {
return 0;
}
return gpiod_get_value(info->ready_gpiod);
}
/**
@ -1755,7 +1753,9 @@ static int omap_nand_probe(struct platform_device *pdev)
info->gpmc_cs = pdata->cs;
info->reg = pdata->reg;
info->ecc_opt = pdata->ecc_opt;
info->dev_ready = pdata->dev_ready;
if (pdata->dev_ready)
dev_info(&pdev->dev, "pdata->dev_ready is deprecated\n");
info->xfer_type = pdata->xfer_type;
info->devsize = pdata->devsize;
info->elm_of_node = pdata->elm_of_node;
@ -1787,6 +1787,13 @@ static int omap_nand_probe(struct platform_device *pdev)
nand_chip->IO_ADDR_W = nand_chip->IO_ADDR_R;
nand_chip->cmd_ctrl = omap_hwcontrol;
info->ready_gpiod = devm_gpiod_get_optional(&pdev->dev, "rb",
GPIOD_IN);
if (IS_ERR(info->ready_gpiod)) {
dev_err(dev, "failed to get ready gpio\n");
return PTR_ERR(info->ready_gpiod);
}
/*
* If RDY/BSY line is connected to OMAP then use the omap ready
* function and the generic nand_wait function which reads the status
@ -1794,7 +1801,7 @@ static int omap_nand_probe(struct platform_device *pdev)
* chip delay which is slightly more than tR (AC Timing) of the NAND
* device and read status register until you get a failure or success
*/
if (info->dev_ready) {
if (info->ready_gpiod) {
nand_chip->dev_ready = omap_dev_ready;
nand_chip->chip_delay = 0;
} else {

2
include/linux/platform_data/mtd-nand-omap2.h
View File

@ -71,7 +71,6 @@ struct omap_nand_platform_data {
int cs;
struct mtd_partition *parts;
int nr_parts;
bool dev_ready;
bool flash_bbt;
enum nand_io xfer_type;
int devsize;
@ -82,5 +81,6 @@ struct omap_nand_platform_data {
/* deprecated */
struct gpmc_nand_regs reg;
struct device_node *of_node;
bool dev_ready;
};
#endif