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Commit 10f22ee3 authored by Roger Quadros's avatar Roger Quadros
Browse files

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: default avatarRoger Quadros <rogerq@ti.com>
Acked-by: default avatarBrian Norris <computersforpeace@gmail.com>
Acked-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: default avatarTony Lindgren <tony@atomide.com>
parent 9e694621

Documentation/devicetree/bindings/mtd/gpmc-nand.txt

+2 −0
Original line number Diff line number Diff line
@@ -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>;

drivers/mtd/nand/omap2.c

+18 −11
Original line number Diff line number Diff line
@@ -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 {

include/linux/platform_data/mtd-nand-omap2.h

+1 −1
Original line number Diff line number Diff line
@@ -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