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>

diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
index ff3215d203431299fe279c96434d27acb0e19f96..3ee7e202657cdb83f7e430ff7b00a29ba69ed097 100644 (file)
--- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
@@ -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>;

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 35b8f3359c176af25785a8975561570e3ac6c395..e0b2b2f0fbdea7cda03746516fb9e726849a5bfa 100644 (file)
--- 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>
@@ -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 {

diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux/platform_data/mtd-nand-omap2.h
index 7f6de5377f803b87efbbffcecaa909a9e2b385e7..17d57a18bac575b94f8aac1a372e642160b0b684 100644 (file)
--- a/include/linux/platform_data/mtd-nand-omap2.h
+++ b/include/linux/platform_data/mtd-nand-omap2.h
@@ -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