[PATCH v2 2/3 v4] mtd: rawnand: ams-delta: use GPIO lookup table

From: Janusz Krzysztofik
Date: Tue Jul 17 2018 - 19:15:17 EST


Now as Amstrad Delta board - the only user of this driver - 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_ function calls with their gpiod_ equivalents.

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

Signed-off-by: Janusz Krzysztofik <jmkrzyszt@xxxxxxxxx>
Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
---
Changelog:
v2: Fix handling of devm_gpiod_get_optional() return values - thanks to
Andy Shevchenko
v3: Remove problematic error code conversion, no longer needed if used
on top of commit d08605a64e67 ("ARM: OMAP1: ams-delta: move late
devices back to init_machine") already in linux-omap and commit
8853daf3b4ac ("gpiolib: Defer on non-DT find_chip_by_name()
failure") already in linux-next - thanks to Boris Brezillon
v4: Fix style issue - thanks to Boris Brezillon

Dependency on commit 8853daf3b4ac ("gpiolib: Defer on non-DT
find_chip_by_name() failure") is not critical for clean build or run, it
only prevents from unexpected future changes to driver initialization
order during device_initall.

drivers/mtd/nand/raw/ams-delta.c | 126 +++++++++++++++++++++------------------
1 file changed, 67 insertions(+), 59 deletions(-)

diff --git a/drivers/mtd/nand/raw/ams-delta.c b/drivers/mtd/nand/raw/ams-delta.c
index 37a3cc21c7bc..2a8872ebd14a 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 out_mtd;
}
+
+ 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;
@@ -230,9 +205,47 @@ 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));
- if (err)
- goto out_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 out_mtd;
+ }
+
+ 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 out_mtd;
+ }
+
+ 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 out_mtd;
+ }
+
+ 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 out_mtd;
+ }
+
+ 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 out_mtd;
+ }
+
+ 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);
+ goto out_mtd;
+ }

/* Scan to find existence of the device */
err = nand_scan(ams_delta_mtd, 1);
@@ -246,9 +259,6 @@ 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 */
--
2.16.4