[PATCH v2 20/22] mtd: nand: omap2: Implement NAND ready using gpiolib

From: Roger Quadros
Date: Fri Aug 07 2015 - 05:16:29 EST


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@xxxxxx>
---
drivers/mtd/nand/omap2.c | 29 +++++++++++++++++-----------
include/linux/platform_data/mtd-nand-omap2.h | 2 +-
2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index b009d1d..8ace767 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -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>
@@ -184,6 +185,8 @@ struct omap_nand_info {
/* fields specific for BCHx_HW ECC scheme */
struct device *elm_dev;
struct device_node *of_node;
+ /* NAND ready gpio */
+ struct gpio_desc *ready_gpiod;
};

/**
@@ -1041,22 +1044,17 @@ 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 = container_of(mtd, struct omap_nand_info,
mtd);

- val = readl(info->reg.gpmc_status);
-
- if ((val & 0x100) == 0x100) {
- return 1;
- } else {
- return 0;
- }
+ return gpiod_get_value(info->ready_gpiod);
}

/**
@@ -1776,7 +1774,9 @@ static int omap_nand_probe(struct platform_device *pdev)
info->reg = pdata->reg;
info->of_node = pdata->of_node;
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;
@@ -1809,6 +1809,13 @@ 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, "ready",
+ 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
@@ -1816,7 +1823,7 @@ 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 {
diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux/platform_data/mtd-nand-omap2.h
index ff27e5a..19e509d 100644
--- a/include/linux/platform_data/mtd-nand-omap2.h
+++ b/include/linux/platform_data/mtd-nand-omap2.h
@@ -70,7 +70,6 @@ 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;
@@ -81,5 +80,6 @@ struct omap_nand_platform_data {
/* deprecated */
struct gpmc_nand_regs reg;
struct device_node *of_node;
+ bool dev_ready;
};
#endif
--
2.1.4

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