[PATCH v2 1/8] MTD: xway: convert to normal platform driver

[Hauke Mehrtens]

On 06/19/2016 01:32 PM, Boris Brezillon wrote:
> Hi Hauke,
> 
> On Sat, 18 Jun 2016 21:14:05 +0200
> Hauke Mehrtens <hauke at hauke-m.de> wrote:
> 
>> Instead of hacking this into the plat_nand driver just make this a
>> normal nand driver.
> 
> Thanks for taking care of that.
> 
>>
>> Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
>> ---
>>  drivers/mtd/nand/Kconfig     |   1 -
>>  drivers/mtd/nand/xway_nand.c | 119 ++++++++++++++++++++++++++++++-------------
>>  2 files changed, 84 insertions(+), 36 deletions(-)
>>
>> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
>> index f05e0e9..d7de2c97 100644
>> --- a/drivers/mtd/nand/Kconfig
>> +++ b/drivers/mtd/nand/Kconfig
>> @@ -539,7 +539,6 @@ config MTD_NAND_FSMC
>>  config MTD_NAND_XWAY
>>  	tristate "Support for NAND on Lantiq XWAY SoC"
>>  	depends on LANTIQ && SOC_TYPE_XWAY
>> -	select MTD_NAND_PLATFORM
>>  	help
>>  	  Enables support for NAND Flash chips on Lantiq XWAY SoCs. NAND is attached
>>  	  to the External Bus Unit (EBU).
>> diff --git a/drivers/mtd/nand/xway_nand.c b/drivers/mtd/nand/xway_nand.c
>> index 0cf0ac0..867a636 100644
>> --- a/drivers/mtd/nand/xway_nand.c
>> +++ b/drivers/mtd/nand/xway_nand.c
>> @@ -4,6 +4,7 @@
>>   *  by the Free Software Foundation.
>>   *
>>   *  Copyright © 2012 John Crispin <blogic at openwrt.org>
>> + *  Copyright © 2016 Hauke Mehrtens <hauke at hauke-m.de>
>>   */
>>  
>>  #include <linux/mtd/nand.h>
>> @@ -54,6 +55,10 @@
>>  #define NAND_CON_CSMUX		(1 << 1)
>>  #define NAND_CON_NANDM		1
>>  
>> +struct xway_nand_data {
>> +	struct nand_chip	chip;
>> +};
>> +
>>  static void xway_reset_chip(struct nand_chip *chip)
>>  {
>>  	unsigned long nandaddr = (unsigned long) chip->IO_ADDR_W;
>> @@ -130,14 +135,50 @@ static unsigned char xway_read_byte(struct mtd_info *mtd)
>>  	return ret;
>>  }
>>  
>> +/*
>> + * Probe for the NAND device.
>> + */
>>  static int xway_nand_probe(struct platform_device *pdev)
>>  {
>> -	struct nand_chip *this = platform_get_drvdata(pdev);
>> -	unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
>> -	const __be32 *cs = of_get_property(pdev->dev.of_node,
>> -					"lantiq,cs", NULL);
>> +	struct xway_nand_data *data;
>> +	struct mtd_info *mtd;
>> +	struct resource *res;
>> +	int err = 0;
>> +	void __iomem *nandaddr;
>> +	const __be32 *cs;
>>  	u32 cs_flag = 0;
>>  
>> +	/* Allocate memory for the device structure (and zero it) */
>> +	data = devm_kzalloc(&pdev->dev, sizeof(struct xway_nand_data),
>> +			    GFP_KERNEL);
>> +	if (!data)
>> +		return -ENOMEM;
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	nandaddr = devm_ioremap_resource(&pdev->dev, res);
>> +	if (IS_ERR(nandaddr))
>> +		return PTR_ERR(nandaddr);
>> +
>> +	nand_set_flash_node(&data->chip, pdev->dev.of_node);
>> +	mtd = nand_to_mtd(&data->chip);
>> +	mtd->dev.parent = &pdev->dev;
>> +
>> +	data->chip.IO_ADDR_R = nandaddr;
>> +	data->chip.IO_ADDR_W = nandaddr;
>> +	data->chip.cmd_ctrl = xway_cmd_ctrl;
>> +	data->chip.dev_ready = xway_dev_ready;
>> +	data->chip.select_chip = xway_select_chip;
>> +	data->chip.read_byte = xway_read_byte;
>> +	data->chip.chip_delay = 30;
>> +
>> +	data->chip.ecc.mode = NAND_ECC_SOFT;
>> +	data->chip.ecc.algo = NAND_ECC_HAMMING;
>> +
>> +	platform_set_drvdata(pdev, data);
>> +	nand_set_controller_data(&data->chip, data);
>> +
>> +	cs = of_get_property(pdev->dev.of_node, "lantiq,cs", NULL);
> 
> It may be a good time to switch to of_property_read_u32() (here or in a
> separate patch).

I will change this.

>> +
>>  	/* load our CS from the DT. Either we find a valid 1 or default to 0 */
>>  	if (cs && (*cs == 1))
>>  		cs_flag = NAND_CON_IN_CS1 | NAND_CON_OUT_CS1;
>> @@ -155,43 +196,51 @@ static int xway_nand_probe(struct platform_device *pdev)
>>  		| cs_flag, EBU_NAND_CON);
>>  
>>  	/* finish with a reset */
>> -	xway_reset_chip(this);
>> -
>> -	return 0;
>> -}
>> +	xway_reset_chip(&data->chip);
>>  
>> -static struct platform_nand_data xway_nand_data = {
>> -	.chip = {
>> -		.nr_chips		= 1,
>> -		.chip_delay		= 30,
>> -	},
>> -	.ctrl = {
>> -		.probe		= xway_nand_probe,
>> -		.cmd_ctrl	= xway_cmd_ctrl,
>> -		.dev_ready	= xway_dev_ready,
>> -		.select_chip	= xway_select_chip,
>> -		.read_byte	= xway_read_byte,
>> +	/* Scan to find existence of the device */
>> +	if (nand_scan(mtd, 1)) {
> 
> How about returning nand_scan() ret code if it's negative.

I will do that.

> 
>> +		err = -ENXIO;
>> +		goto out;
> 
> This out label seems useless here, just return the err code directly.

I will remove this.

> 
>>  	}
>> -};
>> +
>> +	err = mtd_device_register(mtd, NULL, 0);
>> +
>> +	if (!err)
>> +		return 0;
>> +
>> +	nand_release(mtd);
> 
> I'd prefer
> 
> 	if (err)
> 		nand_release(mtd);
> 
> 	return err;
> 

I will change that.

>> +out:
>> +	return err;
>> +}
>>  
>>  /*
>> - * Try to find the node inside the DT. If it is available attach out
>> - * platform_nand_data
>> + * Remove a NAND device.
>>   */
>> -static int __init xway_register_nand(void)
>> +static int xway_nand_remove(struct platform_device *pdev)
>>  {
>> -	struct device_node *node;
>> -	struct platform_device *pdev;
>> -
>> -	node = of_find_compatible_node(NULL, NULL, "lantiq,nand-xway");
>> -	if (!node)
>> -		return -ENOENT;
>> -	pdev = of_find_device_by_node(node);
>> -	if (!pdev)
>> -		return -EINVAL;
>> -	pdev->dev.platform_data = &xway_nand_data;
>> -	of_node_put(node);
>> +	struct xway_nand_data *data = platform_get_drvdata(pdev);
>> +
>> +	nand_release(nand_to_mtd(&data->chip));
>> +
>>  	return 0;
>>  }
>>  
>> -subsys_initcall(xway_register_nand);
>> +static const struct of_device_id xway_nand_match[] = {
>> +	{ .compatible = "lantiq,nand-xway" },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, xway_nand_match);
>> +
>> +static struct platform_driver xway_nand_driver = {
>> +	.probe	= xway_nand_probe,
>> +	.remove	= xway_nand_remove,
>> +	.driver	= {
>> +		.name		= "lantiq,nand-xway",
>> +		.of_match_table = xway_nand_match,
>> +	},
>> +};
>> +
>> +module_platform_driver(xway_nand_driver);
>> +
>> +MODULE_LICENSE("GPL");
>