Don't readw()/writew() data directly from/to GPIO port which is under
control of gpio-omap driver, use GPIO chip callbacks instead.

Thanks to utilization of get/set_multiple() callbacks, performance
degrade is minor for typical data transfers.

The driver should now work with any 8+-bit bidirectional GPIO port,
not only OMAP.

Signed-off-by: Janusz Krzysztofik <jmkrzy...@gmail.com>

# Conflicts:
#       drivers/mtd/nand/raw/ams-delta.c
---
 arch/arm/mach-omap1/board-ams-delta.c |  11 ----
 drivers/mtd/nand/raw/ams-delta.c      | 119 +++++++++++++++-------------------
 2 files changed, 52 insertions(+), 78 deletions(-)

diff --git a/arch/arm/mach-omap1/board-ams-delta.c 
b/arch/arm/mach-omap1/board-ams-delta.c
index 16f7bbe47607..08e732bc1cd2 100644
--- a/arch/arm/mach-omap1/board-ams-delta.c
+++ b/arch/arm/mach-omap1/board-ams-delta.c
@@ -321,20 +321,9 @@ struct modem_private_data {
 
 static struct modem_private_data modem_priv;
 
-static struct resource ams_delta_nand_resources[] = {
-       [0] = {
-               .start  = OMAP1_MPUIO_BASE,
-               .end    = OMAP1_MPUIO_BASE +
-                               OMAP_MPUIO_IO_CNTL + sizeof(u32) - 1,
-               .flags  = IORESOURCE_MEM,
-       },
-};
-
 static struct platform_device ams_delta_nand_device = {
        .name   = "ams-delta-nand",
        .id     = -1,
-       .num_resources  = ARRAY_SIZE(ams_delta_nand_resources),
-       .resource       = ams_delta_nand_resources,
 };
 
 #define OMAP_GPIO_LABEL                "gpio-0-15"
diff --git a/drivers/mtd/nand/raw/ams-delta.c b/drivers/mtd/nand/raw/ams-delta.c
index bd501f385e78..8fac8d2a444a 100644
--- a/drivers/mtd/nand/raw/ams-delta.c
+++ b/drivers/mtd/nand/raw/ams-delta.c
@@ -25,13 +25,11 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/rawnand.h>
 #include <linux/mtd/partitions.h>
-#include <linux/platform_data/gpio-omap.h>
+#include <linux/platform_device.h>
 
 #include <asm/io.h>
 #include <asm/sizes.h>
 
-#include <mach/hardware.h>
-
 /*
  * MTD structure for E3 (Delta)
  */
@@ -45,7 +43,9 @@ struct ams_delta_nand {
        struct gpio_desc        *gpiod_nwe;
        struct gpio_desc        *gpiod_ale;
        struct gpio_desc        *gpiod_cle;
-       void __iomem            *io_base;
+       struct gpio_chip        *data_gpioc;
+       unsigned long           data_mask;
+       int                     data_width;
 };
 
 /*
@@ -73,43 +73,55 @@ static const struct mtd_partition partition_info[] = {
          .size         =  3 * SZ_256K },
 };
 
-static void ams_delta_write_next_byte(struct ams_delta_nand *priv, u_char byte)
+static void ams_delta_write_commit(struct ams_delta_nand *priv)
 {
-       struct nand_chip *this = &priv->nand_chip;
-
-       writew(byte, this->IO_ADDR_W);
        gpiod_set_value(priv->gpiod_nwe, 0);
        ndelay(40);
        gpiod_set_value(priv->gpiod_nwe, 1);
 }
 
+static void ams_delta_write_next_byte(struct ams_delta_nand *priv, u_char byte)
+{
+       struct gpio_chip *data_gpioc = priv->data_gpioc;
+       unsigned long bits = byte;
+
+       data_gpioc->set_multiple(data_gpioc, &priv->data_mask, &bits);
+
+       ams_delta_write_commit(priv);
+}
+
 static void ams_delta_write_first_byte(struct ams_delta_nand *priv, u_char 
byte)
 {
-       void __iomem *io_base = priv->io_base;
+       struct gpio_chip *data_gpioc = priv->data_gpioc;
+       unsigned long bits = byte;
+       int i;
 
-       writew(0, io_base + OMAP_MPUIO_IO_CNTL);
+       for (i = 0; i < priv->data_width; i++)
+               data_gpioc->direction_output(data_gpioc, i, test_bit(i, &bits));
 
-       ams_delta_write_next_byte(priv, byte);
+       ams_delta_write_commit(priv);
 }
 
 static u_char ams_delta_read_next_byte(struct ams_delta_nand *priv)
 {
-       struct nand_chip *this = &priv->nand_chip;
-       u_char res;
+       struct gpio_chip *data_gpioc = priv->data_gpioc;
+       unsigned long bits;
 
        gpiod_set_value(priv->gpiod_nre, 0);
        ndelay(40);
-       res = readw(this->IO_ADDR_R);
+       data_gpioc->get_multiple(data_gpioc, &priv->data_mask, &bits);
        gpiod_set_value(priv->gpiod_nre, 1);
 
-       return res;
+       return bits;
 }
 
 static u_char ams_delta_read_first_byte(struct ams_delta_nand *priv)
 {
-       void __iomem *io_base = priv->io_base;
+       struct gpio_chip *data_gpioc = priv->data_gpioc;
+       int i;
 
-       writew(~0, io_base + OMAP_MPUIO_IO_CNTL);
+       for (i = 0; i < priv->data_width; i++)
+               data_gpioc->direction_input(data_gpioc, i);
 
        return ams_delta_read_next_byte(priv);
 }
@@ -188,16 +200,11 @@ static int ams_delta_init(struct platform_device *pdev)
        struct ams_delta_nand *priv;
        struct nand_chip *this;
        struct mtd_info *mtd;
-       struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-       void __iomem *io_base;
        struct gpio_descs *data_gpiods;
        struct gpio_chip *data_gpioc;
        unsigned long mask, bits;
        int i, err = 0;
 
-       if (!res)
-               return -ENXIO;
-
        /* Allocate memory for MTD device structure and private data */
        priv = devm_kzalloc(&pdev->dev, sizeof(struct ams_delta_nand),
                            GFP_KERNEL);
@@ -210,25 +217,8 @@ static int ams_delta_init(struct platform_device *pdev)
        mtd = nand_to_mtd(this);
        mtd->dev.parent = &pdev->dev;
 
-       /*
-        * Don't try to request the memory region from here,
-        * it should have been already requested from the
-        * gpio-omap driver and requesting it again would fail.
-        */
-
-       io_base = ioremap(res->start, resource_size(res));
-       if (io_base == NULL) {
-               dev_err(&pdev->dev, "ioremap failed\n");
-               err = -EIO;
-               goto out_free;
-       }
-
-       priv->io_base = io_base;
        nand_set_controller_data(this, priv);
 
-       /* Set address of NAND IO lines */
-       this->IO_ADDR_R = io_base + OMAP_MPUIO_INPUT_LATCH;
-       this->IO_ADDR_W = io_base + OMAP_MPUIO_OUTPUT;
        this->read_byte = ams_delta_read_byte;
        this->write_buf = ams_delta_write_buf;
        this->read_buf = ams_delta_read_buf;
@@ -238,7 +228,7 @@ static int ams_delta_init(struct platform_device *pdev)
        if (IS_ERR(priv->gpiod_rdy)) {
                err = PTR_ERR(priv->gpiod_rdy);
                dev_warn(&pdev->dev, "RDY GPIO request failed (%d)\n", err);
-               goto out_mtd;
+               return err;
        }
 
        if (priv->gpiod_rdy)
@@ -256,49 +246,49 @@ static int ams_delta_init(struct platform_device *pdev)
        if (IS_ERR(priv->gpiod_nwp)) {
                err = PTR_ERR(priv->gpiod_nwp);
                dev_err(&pdev->dev, "NWP GPIO request failed (%d)\n", err);
-               goto out_mtd;
+               return err;
        }
 
        priv->gpiod_nce = devm_gpiod_get(&pdev->dev, "nce", GPIOD_OUT_HIGH);
        if (IS_ERR(priv->gpiod_nce)) {
                err = PTR_ERR(priv->gpiod_nce);
                dev_err(&pdev->dev, "NCE GPIO request failed (%d)\n", err);
-               goto out_mtd;
+               return err;
        }
 
        priv->gpiod_nre = devm_gpiod_get(&pdev->dev, "nre", GPIOD_OUT_HIGH);
        if (IS_ERR(priv->gpiod_nre)) {
                err = PTR_ERR(priv->gpiod_nre);
                dev_err(&pdev->dev, "NRE GPIO request failed (%d)\n", err);
-               goto out_mtd;
+               return err;
        }
 
        priv->gpiod_nwe = devm_gpiod_get(&pdev->dev, "nwe", GPIOD_OUT_HIGH);
        if (IS_ERR(priv->gpiod_nwe)) {
                err = PTR_ERR(priv->gpiod_nwe);
                dev_err(&pdev->dev, "NWE GPIO request failed (%d)\n", err);
-               goto out_mtd;
+               return err;
        }
 
        priv->gpiod_ale = devm_gpiod_get(&pdev->dev, "ale", GPIOD_OUT_LOW);
        if (IS_ERR(priv->gpiod_ale)) {
                err = PTR_ERR(priv->gpiod_ale);
                dev_err(&pdev->dev, "ALE GPIO request failed (%d)\n", err);
-               goto out_mtd;
+               return err;
        }
 
        priv->gpiod_cle = devm_gpiod_get(&pdev->dev, "cle", GPIOD_OUT_LOW);
        if (IS_ERR(priv->gpiod_cle)) {
                err = PTR_ERR(priv->gpiod_cle);
                dev_err(&pdev->dev, "CLE GPIO request failed (%d)\n", err);
-               goto out_mtd;
+               return err;
        }
        /* Request array of data pins, initialize them as output and set low */
        data_gpiods = devm_gpiod_get_array(&pdev->dev, "data", GPIOD_OUT_LOW);
        if (IS_ERR(data_gpiods)) {
                err = PTR_ERR(data_gpiods);
                dev_err(&pdev->dev, "data GPIO request failed: %d\n", err);
-               goto out_mtd;
+               return err;
        }
 
        /* Use GPIO chip of first data GPIO pin descriptor */
@@ -312,7 +302,7 @@ static int ams_delta_init(struct platform_device *pdev)
                err = -EINVAL;
                dev_err(&pdev->dev,
                        "data GPIO chip does not support get/set_multiple()\n");
-               goto out_mtd;
+               return err;
        }
 
        /* Verify if get_multiple() returns all pins low as initialized above */
@@ -321,13 +311,13 @@ static int ams_delta_init(struct platform_device *pdev)
        if (err) {
                dev_err(&pdev->dev,
                        "data GPIO chip get_multiple() failed: %d\n", err);
-               goto out_mtd;
+               return err;
        }
        if (bits) {
                err = -EINVAL;
                dev_err(&pdev->dev,
                        "mismmatch of data GPIO initial value: %lu\n", bits);
-               goto out_mtd;
+               return err;
        }
 
        /* Verify each data GPIO pin */
@@ -337,7 +327,7 @@ static int ams_delta_init(struct platform_device *pdev)
                        err = -EINVAL;
                        dev_err(&pdev->dev, "GPIO chip mismatch of data bit 
%d\n",
                                i);
-                       goto out_mtd;
+                       return err;
                }
 
                /* Require all pins active high (not inverted) */
@@ -346,7 +336,7 @@ static int ams_delta_init(struct platform_device *pdev)
                        dev_err(&pdev->dev,
                                "unsupported polarity of data GPIO bit %d\n",
                                i);
-                       goto out_mtd;
+                       return err;
                }
 
                /*
@@ -360,13 +350,13 @@ static int ams_delta_init(struct platform_device *pdev)
                        dev_err(&pdev->dev,
                                "data bit %d GPIO chip get() failed: %d\n", i,
                                err);
-                       goto out_mtd;
+                       return err;
                }
                if (!err) {
                        err = -EINVAL;
                        dev_err(&pdev->dev, "mismatch of data GPIO bit %d 
value\n",
                                i);
-                       goto out_mtd;
+                       return err;
                }
 
                /*
@@ -379,14 +369,18 @@ static int ams_delta_init(struct platform_device *pdev)
                        dev_err(&pdev->dev,
                                "unsupported mode of data GPIO bit %d\n",
                                i);
-                       goto out_mtd;
+                       return err;
                }
        }
 
+       priv->data_gpioc = data_gpioc;
+       priv->data_width = data_gpiods->ndescs;
+       priv->data_mask = (1 << data_gpiods->ndescs) - 1;
+
        /* Scan to find existence of the device */
        err = nand_scan(mtd, 1);
        if (err)
-               goto out_mtd;
+               return err;
 
        /* As soon as the device is found, release write protection */
        gpiod_set_value(priv->gpiod_nwp, 1);
@@ -394,13 +388,7 @@ static int ams_delta_init(struct platform_device *pdev)
        /* Register the partitions */
        mtd_device_register(mtd, partition_info, ARRAY_SIZE(partition_info));
 
-       goto out;
-
- out_mtd:
-       iounmap(io_base);
-out_free:
- out:
-       return err;
+       return 0;
 }
 
 /*
@@ -410,16 +398,13 @@ static int ams_delta_cleanup(struct platform_device *pdev)
 {
        struct ams_delta_nand *priv = platform_get_drvdata(pdev);
        struct mtd_info *mtd = nand_to_mtd(&priv->nand_chip);
-       void __iomem *io_base = priv->io_base;
 
        /* Apply write protection */
        gpiod_set_value(priv->gpiod_nwp, 0);
 
-       /* Release resources, unregister device */
+       /* Unregister device */
        nand_release(mtd);
 
-       iounmap(io_base);
-
        return 0;
 }
 
-- 
2.16.4

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