[PATCH 5/6 v2] mtd: rawnand: ams-delta: use GPIO lookup table

[Janusz Krzysztofik]

Now as the Amstrad Delta board provides GPIO lookup tables, switch from
GPIO numbers to GPIO descriptors and use the table to locate required
GPIO pins.

Declare static variables for storing GPIO descriptors and replace
gpio_ functions with their gpiod_ equivalents. Return -EPROBE_DEFER
if the GPIO pins are not yet available so device initialization is
postponed instead of aborted.

Pin naming used by the driver should be followed while respective GPIO
lookup table is initialized by a board init code.

Created and tested against linux-4.17-rc3, on top of patch 1/6 "ARM:
OMAP1: ams-delta: add GPIO lookup tables" (already applied to
omap-for-v4.18/soc tree).

Changes since v1:
- fix handling of devm_gpiod_get_optional() return values - thanks to
  Andy Shevchenko.

Signed-off-by: Janusz Krzysztofik <jmkrzyszt@xxxxxxxxx>
---
 drivers/mtd/nand/raw/ams-delta.c | 120 +++++++++++++++++++++------------------
 1 file changed, 64 insertions(+), 56 deletions(-)

diff --git a/drivers/mtd/nand/raw/ams-delta.c b/drivers/mtd/nand/raw/ams-delta.c
index 37a3cc21c7bc..524ceaf12de0 100644
--- a/drivers/mtd/nand/raw/ams-delta.c
+++ b/drivers/mtd/nand/raw/ams-delta.c
@@ -20,23 +20,28 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/delay.h>
+#include <linux/gpio/consumer.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/rawnand.h>
 #include <linux/mtd/partitions.h>
-#include <linux/gpio.h>
 #include <linux/platform_data/gpio-omap.h>
 
 #include <asm/io.h>
 #include <asm/sizes.h>
 
-#include <mach/board-ams-delta.h>
-
 #include <mach/hardware.h>
 
 /*
  * MTD structure for E3 (Delta)
  */
 static struct mtd_info *ams_delta_mtd = NULL;
+static struct gpio_desc *gpiod_rdy;
+static struct gpio_desc *gpiod_nce;
+static struct gpio_desc *gpiod_nre;
+static struct gpio_desc *gpiod_nwp;
+static struct gpio_desc *gpiod_nwe;
+static struct gpio_desc *gpiod_ale;
+static struct gpio_desc *gpiod_cle;
 
 /*
  * Define partitions for flash devices
@@ -70,9 +75,9 @@ static void ams_delta_write_byte(struct mtd_info *mtd, u_char byte)
 
 	writew(0, io_base + OMAP_MPUIO_IO_CNTL);
 	writew(byte, this->IO_ADDR_W);
-	gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NWE, 0);
+	gpiod_set_value(gpiod_nwe, 0);
 	ndelay(40);
-	gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NWE, 1);
+	gpiod_set_value(gpiod_nwe, 1);
 }
 
 static u_char ams_delta_read_byte(struct mtd_info *mtd)
@@ -81,11 +86,11 @@ static u_char ams_delta_read_byte(struct mtd_info *mtd)
 	struct nand_chip *this = mtd_to_nand(mtd);
 	void __iomem *io_base = (void __iomem *)nand_get_controller_data(this);
 
-	gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NRE, 0);
+	gpiod_set_value(gpiod_nre, 0);
 	ndelay(40);
 	writew(~0, io_base + OMAP_MPUIO_IO_CNTL);
 	res = readw(this->IO_ADDR_R);
-	gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NRE, 1);
+	gpiod_set_value(gpiod_nre, 1);
 
 	return res;
 }
@@ -120,12 +125,9 @@ static void ams_delta_hwcontrol(struct mtd_info *mtd, int cmd,
 {
 
 	if (ctrl & NAND_CTRL_CHANGE) {
-		gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NCE,
-				(ctrl & NAND_NCE) == 0);
-		gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_CLE,
-				(ctrl & NAND_CLE) != 0);
-		gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_ALE,
-				(ctrl & NAND_ALE) != 0);
+		gpiod_set_value(gpiod_nce, !(ctrl & NAND_NCE));
+		gpiod_set_value(gpiod_cle, !!(ctrl & NAND_CLE));
+		gpiod_set_value(gpiod_ale, !!(ctrl & NAND_ALE));
 	}
 
 	if (cmd != NAND_CMD_NONE)
@@ -134,41 +136,9 @@ static void ams_delta_hwcontrol(struct mtd_info *mtd, int cmd,
 
 static int ams_delta_nand_ready(struct mtd_info *mtd)
 {
-	return gpio_get_value(AMS_DELTA_GPIO_PIN_NAND_RB);
+	return gpiod_get_value(gpiod_rdy);
 }
 
-static const struct gpio _mandatory_gpio[] = {
-	{
-		.gpio	= AMS_DELTA_GPIO_PIN_NAND_NCE,
-		.flags	= GPIOF_OUT_INIT_HIGH,
-		.label	= "nand_nce",
-	},
-	{
-		.gpio	= AMS_DELTA_GPIO_PIN_NAND_NRE,
-		.flags	= GPIOF_OUT_INIT_HIGH,
-		.label	= "nand_nre",
-	},
-	{
-		.gpio	= AMS_DELTA_GPIO_PIN_NAND_NWP,
-		.flags	= GPIOF_OUT_INIT_HIGH,
-		.label	= "nand_nwp",
-	},
-	{
-		.gpio	= AMS_DELTA_GPIO_PIN_NAND_NWE,
-		.flags	= GPIOF_OUT_INIT_HIGH,
-		.label	= "nand_nwe",
-	},
-	{
-		.gpio	= AMS_DELTA_GPIO_PIN_NAND_ALE,
-		.flags	= GPIOF_OUT_INIT_LOW,
-		.label	= "nand_ale",
-	},
-	{
-		.gpio	= AMS_DELTA_GPIO_PIN_NAND_CLE,
-		.flags	= GPIOF_OUT_INIT_LOW,
-		.label	= "nand_cle",
-	},
-};
 
 /*
  * Main initialization routine
@@ -216,12 +186,17 @@ static int ams_delta_init(struct platform_device *pdev)
 	this->write_buf = ams_delta_write_buf;
 	this->read_buf = ams_delta_read_buf;
 	this->cmd_ctrl = ams_delta_hwcontrol;
-	if (gpio_request(AMS_DELTA_GPIO_PIN_NAND_RB, "nand_rdy") == 0) {
-		this->dev_ready = ams_delta_nand_ready;
-	} else {
-		this->dev_ready = NULL;
-		pr_notice("Couldn't request gpio for Delta NAND ready.\n");
+
+	gpiod_rdy = devm_gpiod_get_optional(&pdev->dev, "rdy", GPIOD_IN);
+	if (IS_ERR(gpiod_rdy)) {
+		err = PTR_ERR(gpiod_rdy);
+		dev_warn(&pdev->dev, "RDY GPIO request failed (%d)\n", err);
+		goto err_gpiod;
 	}
+
+	if (gpiod_rdy)
+		this->dev_ready = ams_delta_nand_ready;
+
 	/* 25 us command delay time */
 	this->chip_delay = 30;
 	this->ecc.mode = NAND_ECC_SOFT;
@@ -230,7 +205,44 @@ static int ams_delta_init(struct platform_device *pdev)
 	platform_set_drvdata(pdev, io_base);
 
 	/* Set chip enabled, but  */
-	err = gpio_request_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
+	gpiod_nwp = devm_gpiod_get(&pdev->dev, "nwp", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpiod_nwp)) {
+		err = PTR_ERR(gpiod_nwp);
+		dev_err(&pdev->dev, "NWP GPIO request failed (%d)\n", err);
+		goto err_gpiod;
+	}
+	gpiod_nce = devm_gpiod_get(&pdev->dev, "nce", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpiod_nce)) {
+		err = PTR_ERR(gpiod_nce);
+		dev_err(&pdev->dev, "NCE GPIO request failed (%d)\n", err);
+		goto err_gpiod;
+	}
+	gpiod_nre = devm_gpiod_get(&pdev->dev, "nre", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpiod_nre)) {
+		err = PTR_ERR(gpiod_nre);
+		dev_err(&pdev->dev, "NRE GPIO request failed (%d)\n", err);
+		goto err_gpiod;
+	}
+	gpiod_nwe = devm_gpiod_get(&pdev->dev, "nwe", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpiod_nwe)) {
+		err = PTR_ERR(gpiod_nwe);
+		dev_err(&pdev->dev, "NWE GPIO request failed (%d)\n", err);
+		goto err_gpiod;
+	}
+	gpiod_ale = devm_gpiod_get(&pdev->dev, "ale", GPIOD_OUT_LOW);
+	if (IS_ERR(gpiod_ale)) {
+		err = PTR_ERR(gpiod_ale);
+		dev_err(&pdev->dev, "ALE GPIO request failed (%d)\n", err);
+		goto err_gpiod;
+	}
+	gpiod_cle = devm_gpiod_get(&pdev->dev, "cle", GPIOD_OUT_LOW);
+	if (IS_ERR(gpiod_cle)) {
+		err = PTR_ERR(gpiod_cle);
+		dev_err(&pdev->dev, "CLE GPIO request failed (%d)\n", err);
+	}
+err_gpiod:
+	if (err == -ENODEV || err == -ENOENT)
+		err = -EPROBE_DEFER;
 	if (err)
 		goto out_gpio;
 
@@ -246,9 +258,7 @@ static int ams_delta_init(struct platform_device *pdev)
 	goto out;
 
  out_mtd:
-	gpio_free_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
 out_gpio:
-	gpio_free(AMS_DELTA_GPIO_PIN_NAND_RB);
 	iounmap(io_base);
 out_free:
 	kfree(this);
@@ -266,8 +276,6 @@ static int ams_delta_cleanup(struct platform_device *pdev)
 	/* Release resources, unregister device */
 	nand_release(ams_delta_mtd);
 
-	gpio_free_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
-	gpio_free(AMS_DELTA_GPIO_PIN_NAND_RB);
 	iounmap(io_base);
 
 	/* Free the MTD device structure */
-- 
2.16.1