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

[Tony Lindgren <tony@atomide.com>]

* Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> [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@tis.icnet.pl>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Tony Lindgren <tony@atomide.com>

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
>