Subject: [PATCH v3] ARM: davinci: aemif: get rid of davinci-nand driver dependency on aemif

From: [email-masked] (ivan.khoronzhuk)
Date: Wed, 18 Dec 2013 13:51:32 +0200

On 12/05/2013 08:11 PM, Ivan Khoronzhuk wrote:
> The problem that the set timings code contains the call of Davinci
> platform function davinci_aemif_setup_timing() which is not
> accessible if kernel is built for another platform like Keystone.
> 
> The Keysone platform is going to use TI AEMIF driver.
> If TI AEMIF is used we don't need to set timings and bus width.
> It is done by AEMIF driver.
> 
> To get rid of davinci-nand driver dependency on aemif platform code
> we moved aemif code to davinci platform.
> 
> The platform AEMIF code (aemif.c) has to be removed once Davinci
> will be converted to DT and use ti-aemif.c driver.
> 
> Signed-off-by: Sekhar Nori <[email-masked]>
> Signed-off-by: Ivan Khoronzhuk <[email-masked]>
> ---
> v3..v2:
> - rebased on following patch series:
> 	[PATCH v3 0/9] Reuse davinci-nand driver for Keystone arch
> 	http://www.spinics.net/lists/arm-kernel/msg291723.html
> - removed AEMIF setup from next boards:
> 	 arch/arm/mach-davinci/board-dm355-evm.c
> 	 arch/arm/mach-davinci/board-dm355-leopard.c
> 	 arch/arm/mach-davinci/board-dm365-evm.c
> 	 arch/arm/mach-davinci/board-neuros-osd2.c
> 	 arch/arm/mach-davinci/devices-tnetv107x.c
> - removed repeated clk_get() from davinci_aemif_setup_timing()
> 
> v2..v1:
> - enabled AEMIF clock
> - removed EXPORT_SYMBOL(davinci_aemif_setup)
> - renamed ugly name davinci_ntosd2_nandflash_device
> CC:
> Sekhar Nori <[email-masked]>
> 
>   arch/arm/mach-davinci/aemif.c                   |  106 ++++++++++++++++++++---
>   arch/arm/mach-davinci/board-da830-evm.c         |    3 +
>   arch/arm/mach-davinci/board-da850-evm.c         |    3 +
>   arch/arm/mach-davinci/board-dm644x-evm.c        |    5 ++
>   arch/arm/mach-davinci/board-dm646x-evm.c        |    3 +
>   arch/arm/mach-davinci/board-mityomapl138.c      |    3 +
>   drivers/mtd/nand/davinci_nand.c                 |   22 -----
>   include/linux/platform_data/mtd-davinci-aemif.h |    5 +-
>   8 files changed, 115 insertions(+), 35 deletions(-)
> 
> diff --git a/arch/arm/mach-davinci/aemif.c b/arch/arm/mach-davinci/aemif.c
> index f091a90..7adfb7e 100644
> --- a/arch/arm/mach-davinci/aemif.c
> +++ b/arch/arm/mach-davinci/aemif.c
> @@ -16,6 +16,7 @@
>   #include <linux/time.h>
>   
>   #include <linux/platform_data/mtd-davinci-aemif.h>
> +#include <linux/platform_data/mtd-davinci.h>
>   
>   /* Timing value configuration */
>   
> @@ -43,6 +44,17 @@
>   				WSTROBE(WSTROBE_MAX) | \
>   				WSETUP(WSETUP_MAX))
>   
> +static inline unsigned int davinci_aemif_readl(void __iomem *base, int offset)
> +{
> +	return readl_relaxed(base + offset);
> +}
> +
> +static inline void davinci_aemif_writel(void __iomem *base,
> +					int offset, unsigned long value)
> +{
> +	writel_relaxed(value, base + offset);
> +}
> +
>   /*
>    * aemif_calc_rate - calculate timing data.
>    * @wanted: The cycle time needed in nanoseconds.
> @@ -76,6 +88,7 @@ static int aemif_calc_rate(int wanted, unsigned long clk, int max)
>    * @t: timing values to be progammed
>    * @base: The virtual base address of the AEMIF interface
>    * @cs: chip-select to program the timing values for
> + * @clkrate: the AEMIF clkrate
>    *
>    * This function programs the given timing values (in real clock) into the
>    * AEMIF registers taking the AEMIF clock into account.
> @@ -86,24 +99,17 @@ static int aemif_calc_rate(int wanted, unsigned long clk, int max)
>    *
>    * Returns 0 on success, else negative errno.
>    */
> -int davinci_aemif_setup_timing(struct davinci_aemif_timing *t,
> -					void __iomem *base, unsigned cs)
> +static int davinci_aemif_setup_timing(struct davinci_aemif_timing *t,
> +					void __iomem *base, unsigned cs,
> +					unsigned long clkrate)
>   {
>   	unsigned set, val;
>   	int ta, rhold, rstrobe, rsetup, whold, wstrobe, wsetup;
>   	unsigned offset = A1CR_OFFSET + cs * 4;
> -	struct clk *aemif_clk;
> -	unsigned long clkrate;
>   
>   	if (!t)
>   		return 0;	/* Nothing to do */
>   
> -	aemif_clk = clk_get(NULL, "aemif");
> -	if (IS_ERR(aemif_clk))
> -		return PTR_ERR(aemif_clk);
> -
> -	clkrate = clk_get_rate(aemif_clk);
> -
>   	clkrate /= 1000;	/* turn clock into kHz for ease of use */
>   
>   	ta	= aemif_calc_rate(t->ta, clkrate, TA_MAX);
> @@ -130,4 +136,82 @@ int davinci_aemif_setup_timing(struct davinci_aemif_timing *t,
>   
>   	return 0;
>   }
> -EXPORT_SYMBOL(davinci_aemif_setup_timing);
> +
> +/**
> + * davinci_aemif_setup - setup AEMIF interface by davinci_nand_pdata
> + * @pdev - link to platform device to setup settings for
> + *
> + * This function does not use any locking while programming the AEMIF
> + * because it is expected that there is only one user of a given
> + * chip-select.
> + *
> + * Returns 0 on success, else negative errno.
> + */
> +int davinci_aemif_setup(struct platform_device *pdev)
> +{
> +	struct davinci_nand_pdata *pdata = dev_get_platdata(&pdev->dev);
> +	uint32_t val;
> +	unsigned long clkrate;
> +	struct resource	*res;
> +	void __iomem *base;
> +	struct clk* clk;
> +	int ret = 0;
> +
> +	clk = clk_get(&pdev->dev, "aemif");
> +	if (IS_ERR(clk)) {
> +		ret = PTR_ERR(clk);
> +		dev_dbg(&pdev->dev, "unable to get AEMIF clock, err %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(clk);
> +	if (ret < 0) {
> +		dev_dbg(&pdev->dev, "unable to enable AEMIF clock, err %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +	if (!res) {
> +		dev_err(&pdev->dev, "cannot get IORESOURCE_MEM\n");
> +		ret = -ENOMEM;
> +		goto err;
> +	}
> +
> +	base = ioremap(res->start, resource_size(res));
> +	if (!base) {
> +		dev_err(&pdev->dev, "ioremap failed for resource %pR\n", res);
> +		ret = -ENOMEM;
> +		goto err;
> +	}
> +
> +	/*
> +	 * Setup Async configuration register in case we did not boot
> +	 * from NAND and so bootloader did not bother to set it up.
> +	 */
> +	val = davinci_aemif_readl(base, A1CR_OFFSET + pdev->id * 4);
> +	/*
> +	 * Extended Wait is not valid and Select Strobe mode is not
> +	 * used
> +	 */
> +	val &= ~(ACR_ASIZE_MASK | ACR_EW_MASK | ACR_SS_MASK);
> +	if (pdata->options & NAND_BUSWIDTH_16)
> +		val |= 0x1;
> +
> +	davinci_aemif_writel(base, A1CR_OFFSET + pdev->id * 4, val);
> +
> +	clkrate = clk_get_rate(clk);
> +
> +	if (pdata->timing)
> +		ret = davinci_aemif_setup_timing(pdata->timing, base, pdev->id,
> +						 clkrate);
> +
> +	if (ret < 0)
> +		dev_dbg(&pdev->dev, "NAND timing values setup fail\n");
> +
> +	iounmap(base);
> +err:
> +	clk_disable_unprepare(clk);
> +	clk_put(clk);
> +	return ret;
> +}
> diff --git a/arch/arm/mach-davinci/board-da830-evm.c b/arch/arm/mach-davinci/board-da830-evm.c
> index d1f45af..5623131 100644
> --- a/arch/arm/mach-davinci/board-da830-evm.c
> +++ b/arch/arm/mach-davinci/board-da830-evm.c
> @@ -419,6 +419,9 @@ static inline void da830_evm_init_nand(int mux_mode)
>   	if (ret)
>   		pr_warning("da830_evm_init: NAND device not registered.\n");
>   
> +	if (davinci_aemif_setup(&da830_evm_nand_device))
> +		pr_warn("%s: Cannot configure AEMIF.\n", __func__);
> +
>   	gpio_direction_output(mux_mode, 1);
>   }
>   #else
> diff --git a/arch/arm/mach-davinci/board-da850-evm.c b/arch/arm/mach-davinci/board-da850-evm.c
> index e0af0ec..234c5bb 100644
> --- a/arch/arm/mach-davinci/board-da850-evm.c
> +++ b/arch/arm/mach-davinci/board-da850-evm.c
> @@ -358,6 +358,9 @@ static inline void da850_evm_setup_nor_nand(void)
>   
>   		platform_add_devices(da850_evm_devices,
>   					ARRAY_SIZE(da850_evm_devices));
> +
> +		if (davinci_aemif_setup(&da850_evm_nandflash_device))
> +			pr_warn("%s: Cannot configure AEMIF.\n", __func__);
>   	}
>   }
>   
> diff --git a/arch/arm/mach-davinci/board-dm644x-evm.c b/arch/arm/mach-davinci/board-dm644x-evm.c
> index 987605b7..5602957 100644
> --- a/arch/arm/mach-davinci/board-dm644x-evm.c
> +++ b/arch/arm/mach-davinci/board-dm644x-evm.c
> @@ -778,6 +778,11 @@ static __init void davinci_evm_init(void)
>   		/* only one device will be jumpered and detected */
>   		if (HAS_NAND) {
>   			platform_device_register(&davinci_evm_nandflash_device);
> +
> +			if (davinci_aemif_setup(&davinci_evm_nandflash_device))
> +				pr_warn("%s: Cannot configure AEMIF.\n",
> +					__func__);
> +
>   			evm_leds[7].default_trigger = "nand-disk";
>   			if (HAS_NOR)
>   				pr_warning("WARNING: both NAND and NOR flash "
> diff --git a/arch/arm/mach-davinci/board-dm646x-evm.c b/arch/arm/mach-davinci/board-dm646x-evm.c
> index 13d0801..ae129bc 100644
> --- a/arch/arm/mach-davinci/board-dm646x-evm.c
> +++ b/arch/arm/mach-davinci/board-dm646x-evm.c
> @@ -805,6 +805,9 @@ static __init void evm_init(void)
>   
>   	platform_device_register(&davinci_nand_device);
>   
> +	if (davinci_aemif_setup(&davinci_nand_device))
> +		pr_warn("%s: Cannot configure AEMIF.\n", __func__);
> +
>   	dm646x_init_edma(dm646x_edma_rsv);
>   
>   	if (HAS_ATA)
> diff --git a/arch/arm/mach-davinci/board-mityomapl138.c b/arch/arm/mach-davinci/board-mityomapl138.c
> index 7aa105b..98a66ff 100644
> --- a/arch/arm/mach-davinci/board-mityomapl138.c
> +++ b/arch/arm/mach-davinci/board-mityomapl138.c
> @@ -432,6 +432,9 @@ static void __init mityomapl138_setup_nand(void)
>   {
>   	platform_add_devices(mityomapl138_devices,
>   				 ARRAY_SIZE(mityomapl138_devices));
> +
> +	if (davinci_aemif_setup(&mityomapl138_nandflash_device))
> +		pr_warn("%s: Cannot configure AEMIF.\n", __func__);
>   }
>   
>   static const short mityomap_mii_pins[] = {
> diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c
> index 0cd4dbc..4463b0e 100644
> --- a/drivers/mtd/nand/davinci_nand.c
> +++ b/drivers/mtd/nand/davinci_nand.c
> @@ -741,28 +741,6 @@ static int __init nand_davinci_probe(struct platform_device *pdev)
>   		goto err_clk_enable;
>   	}
>   
> -	/*
> -	 * Setup Async configuration register in case we did not boot from
> -	 * NAND and so bootloader did not bother to set it up.
> -	 */
> -	val = davinci_nand_readl(info, A1CR_OFFSET + info->core_chipsel * 4);
> -
> -	/* Extended Wait is not valid and Select Strobe mode is not used */
> -	val &= ~(ACR_ASIZE_MASK | ACR_EW_MASK | ACR_SS_MASK);
> -	if (info->chip.options & NAND_BUSWIDTH_16)
> -		val |= 0x1;
> -
> -	davinci_nand_writel(info, A1CR_OFFSET + info->core_chipsel * 4, val);
> -
> -	ret = 0;
> -	if (info->timing)
> -		ret = davinci_aemif_setup_timing(info->timing, info->base,
> -							info->core_chipsel);
> -	if (ret < 0) {
> -		dev_dbg(&pdev->dev, "NAND timing values setup fail\n");
> -		goto err;
> -	}
> -
>   	spin_lock_irq(&davinci_nand_lock);
>   
>   	/* put CSxNAND into NAND mode */
> diff --git a/include/linux/platform_data/mtd-davinci-aemif.h b/include/linux/platform_data/mtd-davinci-aemif.h
> index 05b2934..97948ac 100644
> --- a/include/linux/platform_data/mtd-davinci-aemif.h
> +++ b/include/linux/platform_data/mtd-davinci-aemif.h
> @@ -10,6 +10,8 @@
>   #ifndef _MACH_DAVINCI_AEMIF_H
>   #define _MACH_DAVINCI_AEMIF_H
>   
> +#include <linux/platform_device.h>
> +
>   #define NRCSR_OFFSET		0x00
>   #define AWCCR_OFFSET		0x04
>   #define A1CR_OFFSET		0x10
> @@ -31,6 +33,5 @@ struct davinci_aemif_timing {
>   	u8	ta;
>   };
>   
> -int davinci_aemif_setup_timing(struct davinci_aemif_timing *t,
> -					void __iomem *base, unsigned cs);
> +int davinci_aemif_setup(struct platform_device *pdev);
>   #endif
> 

Hi, Sekhar

This patch is based on "Reuse davinci-nand driver for Keystone arch" series.
The series has passed review at https://lkml.org/lkml/2013/12/17/241
and can be found at http://git.infradead.org/l2-mtd.git

This patch can be still applied on top of the series without conflicts. 

Can you please pick up the $subject patch if you are OK with it?

-- 
Regards,
Ivan Khoronzhuk