Re: [PATCH v2 5/7] MTD: NAND: ams-delta: use GPIO instead ofcustom I/O

From: Tony Lindgren
Date: Wed Dec 21 2011 - 14:12:21 EST

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* Janusz Krzysztofik <jkrzyszt@xxxxxxxxxxxx> [111219 14:41]:
> Don't use Amstrad Delta custom I/O functions for controlling the device,
> use GPIO API instead.
>
> While being at it, add missing gpio_free(AMS_DELTA_GPIO_PIN_NAND_RB).
>
> Depends on patch 2/7 "ARM: OMAP1: ams-delta: convert latches to
> basic_mmio_gpio"
>
> Signed-off-by: Janusz Krzysztofik <jkrzyszt@xxxxxxxxxxxx>
> Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
> Cc: Tony Lindgren <tony@xxxxxxxxxxx>

Artem, care to ack this one?

Regards,

Tony

> ---
> Changes against initial version:
> * no functional changes,
> * rebased on top of v2 of patch 2/7, just in case.
>
> Comments copied from initial submission:
>
> Hi,
> I considered dropping the Amstrad Delta NAND driver and moving to either
> gpio-nand or gen_nand, but finally decided to keep it for now.
>
> The problem with the gpio-nand is that it seems to match a different
> hardware interface model. Having no knowledge about the original
> hardware that driver was designed in mind, I'd rather not try to
> modify it, and creating another GPIO based NAND driver also seems not
> a really good idea.
>
> If I decided to use gen_nand instead, I would have to move virtually all
> of the old driver callback functions somewhere under arch, either to the
> board file or to a new one, and still use some hacks unless either
> nand_base.c or plat_nand.c is modified.
>
> I'm willing to take one of those two approaches in a follow up series if
> I get a positive feedback.
>
> Thanks,
> Janusz
>
>
> arch/arm/mach-omap1/board-ams-delta.c | 30 --------
> arch/arm/plat-omap/include/plat/board-ams-delta.h | 6 --
> drivers/mtd/nand/ams-delta.c | 74 ++++++++++++++------
> 3 files changed, 52 insertions(+), 58 deletions(-)
>
> diff --git a/arch/arm/mach-omap1/board-ams-delta.c b/arch/arm/mach-omap1/board-ams-delta.c
> index 034d009..cc6f962 100644
> --- a/arch/arm/mach-omap1/board-ams-delta.c
> +++ b/arch/arm/mach-omap1/board-ams-delta.c
> @@ -237,36 +237,6 @@ static struct gpio latch_gpios[] __initconst = {
> .label = "lcd_ndisp",
> },
> {
> - .gpio = AMS_DELTA_GPIO_PIN_NAND_NCE,
> - .flags = GPIOF_OUT_INIT_LOW,
> - .label = "nand_nce",
> - },
> - {
> - .gpio = AMS_DELTA_GPIO_PIN_NAND_NRE,
> - .flags = GPIOF_OUT_INIT_LOW,
> - .label = "nand_nre",
> - },
> - {
> - .gpio = AMS_DELTA_GPIO_PIN_NAND_NWP,
> - .flags = GPIOF_OUT_INIT_LOW,
> - .label = "nand_nwp",
> - },
> - {
> - .gpio = AMS_DELTA_GPIO_PIN_NAND_NWE,
> - .flags = GPIOF_OUT_INIT_LOW,
> - .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",
> - },
> - {
> .gpio = AMS_DELTA_GPIO_PIN_KEYBRD_PWR,
> .flags = GPIOF_OUT_INIT_LOW,
> .label = "keybrd_pwr",
> diff --git a/arch/arm/plat-omap/include/plat/board-ams-delta.h b/arch/arm/plat-omap/include/plat/board-ams-delta.h
> index a0f86ca..3e57833 100644
> --- a/arch/arm/plat-omap/include/plat/board-ams-delta.h
> +++ b/arch/arm/plat-omap/include/plat/board-ams-delta.h
> @@ -30,12 +30,6 @@
>
> #define AMS_DELTA_LATCH2_LCD_VBLEN 0x0001
> #define AMS_DELTA_LATCH2_LCD_NDISP 0x0002
> -#define AMS_DELTA_LATCH2_NAND_NCE 0x0004
> -#define AMS_DELTA_LATCH2_NAND_NRE 0x0008
> -#define AMS_DELTA_LATCH2_NAND_NWP 0x0010
> -#define AMS_DELTA_LATCH2_NAND_NWE 0x0020
> -#define AMS_DELTA_LATCH2_NAND_ALE 0x0040
> -#define AMS_DELTA_LATCH2_NAND_CLE 0x0080
> #define AMD_DELTA_LATCH2_KEYBRD_PWR 0x0100
> #define AMD_DELTA_LATCH2_KEYBRD_DATA 0x0200
> #define AMD_DELTA_LATCH2_SCARD_RSTIN 0x0400
> diff --git a/drivers/mtd/nand/ams-delta.c b/drivers/mtd/nand/ams-delta.c
> index 9e6b498..5769bd2 100644
> --- a/drivers/mtd/nand/ams-delta.c
> +++ b/drivers/mtd/nand/ams-delta.c
> @@ -26,7 +26,7 @@
> #include <asm/io.h>
> #include <mach/hardware.h>
> #include <asm/sizes.h>
> -#include <asm/gpio.h>
> +#include <linux/gpio.h>
> #include <plat/board-ams-delta.h>
>
> /*
> @@ -34,8 +34,6 @@
> */
> static struct mtd_info *ams_delta_mtd = NULL;
>
> -#define NAND_MASK (AMS_DELTA_LATCH2_NAND_NRE | AMS_DELTA_LATCH2_NAND_NWE | AMS_DELTA_LATCH2_NAND_CLE | AMS_DELTA_LATCH2_NAND_ALE | AMS_DELTA_LATCH2_NAND_NCE | AMS_DELTA_LATCH2_NAND_NWP)
> -
> /*
> * Define partitions for flash devices
> */
> @@ -68,10 +66,9 @@ 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);
> - ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NWE, 0);
> + gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NWE, 0);
> ndelay(40);
> - ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NWE,
> - AMS_DELTA_LATCH2_NAND_NWE);
> + gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NWE, 1);
> }
>
> static u_char ams_delta_read_byte(struct mtd_info *mtd)
> @@ -80,12 +77,11 @@ static u_char ams_delta_read_byte(struct mtd_info *mtd)
> struct nand_chip *this = mtd->priv;
> void __iomem *io_base = this->priv;
>
> - ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NRE, 0);
> + gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NRE, 0);
> ndelay(40);
> writew(~0, io_base + OMAP_MPUIO_IO_CNTL);
> res = readw(this->IO_ADDR_R);
> - ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_NRE,
> - AMS_DELTA_LATCH2_NAND_NRE);
> + gpio_set_value(AMS_DELTA_GPIO_PIN_NAND_NRE, 1);
>
> return res;
> }
> @@ -132,15 +128,12 @@ static void ams_delta_hwcontrol(struct mtd_info *mtd, int cmd,
> {
>
> if (ctrl & NAND_CTRL_CHANGE) {
> - unsigned long bits;
> -
> - bits = (~ctrl & NAND_NCE) ? AMS_DELTA_LATCH2_NAND_NCE : 0;
> - bits |= (ctrl & NAND_CLE) ? AMS_DELTA_LATCH2_NAND_CLE : 0;
> - bits |= (ctrl & NAND_ALE) ? AMS_DELTA_LATCH2_NAND_ALE : 0;
> -
> - ams_delta_latch2_write(AMS_DELTA_LATCH2_NAND_CLE |
> - AMS_DELTA_LATCH2_NAND_ALE |
> - AMS_DELTA_LATCH2_NAND_NCE, bits);
> + 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);
> }
>
> if (cmd != NAND_CMD_NONE)
> @@ -152,6 +145,39 @@ static int ams_delta_nand_ready(struct mtd_info *mtd)
> return gpio_get_value(AMS_DELTA_GPIO_PIN_NAND_RB);
> }
>
> +static struct gpio _mandatory_gpio[] __initconst_or_module = {
> + {
> + .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
> */
> @@ -223,10 +249,9 @@ static int __devinit ams_delta_init(struct platform_device *pdev)
> platform_set_drvdata(pdev, io_base);
>
> /* Set chip enabled, but */
> - ams_delta_latch2_write(NAND_MASK, AMS_DELTA_LATCH2_NAND_NRE |
> - AMS_DELTA_LATCH2_NAND_NWE |
> - AMS_DELTA_LATCH2_NAND_NCE |
> - AMS_DELTA_LATCH2_NAND_NWP);
> + err = gpio_request_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
> + if (err)
> + goto out_gpio;
>
> /* Scan to find existence of the device */
> if (nand_scan(ams_delta_mtd, 1)) {
> @@ -241,7 +266,10 @@ static int __devinit ams_delta_init(struct platform_device *pdev)
> goto out;
>
> out_mtd:
> + gpio_free_array(_mandatory_gpio, ARRAY_SIZE(_mandatory_gpio));
> +out_gpio:
> platform_set_drvdata(pdev, NULL);
> + gpio_free(AMS_DELTA_GPIO_PIN_NAND_RB);
> iounmap(io_base);
> out_release_io:
> release_mem_region(res->start, resource_size(res));
> @@ -262,6 +290,8 @@ static int __devexit 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);
> release_mem_region(res->start, resource_size(res));
>
> --
> 1.7.3.4
>
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Next message: John W. Linville: "Re: linux-next: Tree for Dec 19 (nfc)"
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In reply to: Janusz Krzysztofik: "[PATCH v2 5/7] MTD: NAND: ams-delta: use GPIO instead of custom I/O"
Next in thread: Janusz Krzysztofik: "Re: [PATCH v2 5/7] MTD: NAND: ams-delta: use GPIO instead of custom I/O"
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