Commit 93af53b8 authored by Ezequiel García's avatar Ezequiel García Committed by Brian Norris
Browse files

nand: omap2: Remove horrible ifdefs to fix module probe 



The current code abuses ifdefs to determine if the selected ECC scheme
is supported by the running kernel. As a result the code is hard to read,
and it also fails to load as a module.

This commit removes all the ifdefs and instead introduces a function
omap2_nand_ecc_check() to check if the ECC is supported by using
IS_ENABLED(CONFIG_xxx).

Since IS_ENABLED() is true when a config is =y or =m, this change fixes the
module so it can be loaded with no issues.

Acked-by: default avatarRoger Quadros <rogerq@ti.com>
Signed-off-by: default avatarEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
parent 2a960cce

drivers/mtd/nand/omap2.c

+71 −59
Original line number Diff line number Diff line
@@ -136,7 +136,6 @@ 


#define BADBLOCK_MARKER_LENGTH		2



#ifdef CONFIG_MTD_NAND_OMAP_BCH

static u_char bch16_vector[] = {0xf5, 0x24, 0x1c, 0xd0, 0x61, 0xb3, 0xf1, 0x55,

				0x2e, 0x2c, 0x86, 0xa3, 0xed, 0x36, 0x1b, 0x78,

				0x48, 0x76, 0xa9, 0x3b, 0x97, 0xd1, 0x7a, 0x93,
@@ -144,7 +143,6 @@ static u_char bch16_vector[] = {0xf5, 0x24, 0x1c, 0xd0, 0x61, 0xb3, 0xf1, 0x55, 
static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc,

	0xac, 0x6b, 0xff, 0x99, 0x7b};

static u_char bch4_vector[] = {0x00, 0x6b, 0x31, 0xdd, 0x41, 0xbc, 0x10};

#endif



/* oob info generated runtime depending on ecc algorithm and layout selected */

static struct nand_ecclayout omap_oobinfo;
@@ -1292,7 +1290,6 @@ static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd, 
	return 0;

}



#ifdef CONFIG_MTD_NAND_OMAP_BCH

/**

 * erased_sector_bitflips - count bit flips

 * @data:	data sector buffer
@@ -1593,33 +1590,71 @@ static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip, 
/**

 * is_elm_present - checks for presence of ELM module by scanning DT nodes

 * @omap_nand_info: NAND device structure containing platform data

 * @bch_type: 0x0=BCH4, 0x1=BCH8, 0x2=BCH16

 */

static int is_elm_present(struct omap_nand_info *info,

			struct device_node *elm_node, enum bch_ecc bch_type)

static bool is_elm_present(struct omap_nand_info *info,

			   struct device_node *elm_node)

{

	struct platform_device *pdev;

	struct nand_ecc_ctrl *ecc = &info->nand.ecc;

	int err;



	/* check whether elm-id is passed via DT */

	if (!elm_node) {

		pr_err("nand: error: ELM DT node not found\n");

		return -ENODEV;

		return false;

	}

	pdev = of_find_device_by_node(elm_node);

	/* check whether ELM device is registered */

	if (!pdev) {

		pr_err("nand: error: ELM device not found\n");

		return -ENODEV;

		return false;

	}

	/* ELM module available, now configure it */

	info->elm_dev = &pdev->dev;

	err = elm_config(info->elm_dev, bch_type,

		(info->mtd.writesize / ecc->size), ecc->size, ecc->bytes);

	return true;

}



	return err;

static bool omap2_nand_ecc_check(struct omap_nand_info *info,

				 struct omap_nand_platform_data	*pdata)

{

	bool ecc_needs_bch, ecc_needs_omap_bch, ecc_needs_elm;



	switch (info->ecc_opt) {

	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:

	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:

		ecc_needs_omap_bch = false;

		ecc_needs_bch = true;

		ecc_needs_elm = false;

		break;

	case OMAP_ECC_BCH4_CODE_HW:

	case OMAP_ECC_BCH8_CODE_HW:

	case OMAP_ECC_BCH16_CODE_HW:

		ecc_needs_omap_bch = true;

		ecc_needs_bch = false;

		ecc_needs_elm = true;

		break;

	default:

		ecc_needs_omap_bch = false;

		ecc_needs_bch = false;

		ecc_needs_elm = false;

		break;

	}



	if (ecc_needs_bch && !IS_ENABLED(CONFIG_MTD_NAND_ECC_BCH)) {

		dev_err(&info->pdev->dev,

			"CONFIG_MTD_NAND_ECC_BCH not enabled\n");

		return false;

	}

	if (ecc_needs_omap_bch && !IS_ENABLED(CONFIG_MTD_NAND_OMAP_BCH)) {

		dev_err(&info->pdev->dev,

			"CONFIG_MTD_NAND_OMAP_BCH not enabled\n");

		return false;

	}

	if (ecc_needs_elm && !is_elm_present(info, pdata->elm_of_node)) {

		dev_err(&info->pdev->dev, "ELM not available\n");

		return false;

	}



	return true;

}

#endif /* CONFIG_MTD_NAND_ECC_BCH */



static int omap_nand_probe(struct platform_device *pdev)

{
@@ -1797,6 +1832,11 @@ static int omap_nand_probe(struct platform_device *pdev) 
		goto return_error;

	}



	if (!omap2_nand_ecc_check(info, pdata)) {

		err = -EINVAL;

		goto return_error;

	}



	/* populate MTD interface based on ECC scheme */

	ecclayout		= &omap_oobinfo;

	switch (info->ecc_opt) {
@@ -1829,7 +1869,6 @@ static int omap_nand_probe(struct platform_device *pdev) 
		break;



	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:

#ifdef CONFIG_MTD_NAND_ECC_BCH

		pr_info("nand: using OMAP_ECC_BCH4_CODE_HW_DETECTION_SW\n");

		nand_chip->ecc.mode		= NAND_ECC_HW;

		nand_chip->ecc.size		= 512;
@@ -1861,14 +1900,8 @@ static int omap_nand_probe(struct platform_device *pdev) 
			err = -EINVAL;

		}

		break;

#else

		pr_err("nand: error: CONFIG_MTD_NAND_ECC_BCH not enabled\n");

		err = -EINVAL;

		goto return_error;

#endif



	case OMAP_ECC_BCH4_CODE_HW:

#ifdef CONFIG_MTD_NAND_OMAP_BCH

		pr_info("nand: using OMAP_ECC_BCH4_CODE_HW ECC scheme\n");

		nand_chip->ecc.mode		= NAND_ECC_HW;

		nand_chip->ecc.size		= 512;
@@ -1890,21 +1923,15 @@ static int omap_nand_probe(struct platform_device *pdev) 
		/* reserved marker already included in ecclayout->eccbytes */

		ecclayout->oobfree->offset	=

				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;

		/* This ECC scheme requires ELM H/W block */

		if (is_elm_present(info, pdata->elm_of_node, BCH4_ECC) < 0) {

			pr_err("nand: error: could not initialize ELM\n");

			err = -ENODEV;



		err = elm_config(info->elm_dev, BCH4_ECC,

				 info->mtd.writesize / nand_chip->ecc.size,

				 nand_chip->ecc.size, nand_chip->ecc.bytes);

		if (err < 0)

			goto return_error;

		}

		break;

#else

		pr_err("nand: error: CONFIG_MTD_NAND_OMAP_BCH not enabled\n");

		err = -EINVAL;

		goto return_error;

#endif



	case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:

#ifdef CONFIG_MTD_NAND_ECC_BCH

		pr_info("nand: using OMAP_ECC_BCH8_CODE_HW_DETECTION_SW\n");

		nand_chip->ecc.mode		= NAND_ECC_HW;

		nand_chip->ecc.size		= 512;
@@ -1937,14 +1964,8 @@ static int omap_nand_probe(struct platform_device *pdev) 
			goto return_error;

		}

		break;

#else

		pr_err("nand: error: CONFIG_MTD_NAND_ECC_BCH not enabled\n");

		err = -EINVAL;

		goto return_error;

#endif



	case OMAP_ECC_BCH8_CODE_HW:

#ifdef CONFIG_MTD_NAND_OMAP_BCH

		pr_info("nand: using OMAP_ECC_BCH8_CODE_HW ECC scheme\n");

		nand_chip->ecc.mode		= NAND_ECC_HW;

		nand_chip->ecc.size		= 512;
@@ -1956,12 +1977,13 @@ static int omap_nand_probe(struct platform_device *pdev) 
		nand_chip->ecc.calculate	= omap_calculate_ecc_bch;

		nand_chip->ecc.read_page	= omap_read_page_bch;

		nand_chip->ecc.write_page	= omap_write_page_bch;

		/* This ECC scheme requires ELM H/W block */

		err = is_elm_present(info, pdata->elm_of_node, BCH8_ECC);

		if (err < 0) {

			pr_err("nand: error: could not initialize ELM\n");



		err = elm_config(info->elm_dev, BCH8_ECC,

				 info->mtd.writesize / nand_chip->ecc.size,

				 nand_chip->ecc.size, nand_chip->ecc.bytes);

		if (err < 0)

			goto return_error;

		}



		/* define ECC layout */

		ecclayout->eccbytes		= nand_chip->ecc.bytes *

							(mtd->writesize /
@@ -1973,14 +1995,8 @@ static int omap_nand_probe(struct platform_device *pdev) 
		ecclayout->oobfree->offset	=

				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;

		break;

#else

		pr_err("nand: error: CONFIG_MTD_NAND_OMAP_BCH not enabled\n");

		err = -EINVAL;

		goto return_error;

#endif



	case OMAP_ECC_BCH16_CODE_HW:

#ifdef CONFIG_MTD_NAND_OMAP_BCH

		pr_info("using OMAP_ECC_BCH16_CODE_HW ECC scheme\n");

		nand_chip->ecc.mode		= NAND_ECC_HW;

		nand_chip->ecc.size		= 512;
@@ -1991,12 +2007,13 @@ static int omap_nand_probe(struct platform_device *pdev) 
		nand_chip->ecc.calculate	= omap_calculate_ecc_bch;

		nand_chip->ecc.read_page	= omap_read_page_bch;

		nand_chip->ecc.write_page	= omap_write_page_bch;

		/* This ECC scheme requires ELM H/W block */

		err = is_elm_present(info, pdata->elm_of_node, BCH16_ECC);

		if (err < 0) {

			pr_err("ELM is required for this ECC scheme\n");



		err = elm_config(info->elm_dev, BCH16_ECC,

				 info->mtd.writesize / nand_chip->ecc.size,

				 nand_chip->ecc.size, nand_chip->ecc.bytes);

		if (err < 0)

			goto return_error;

		}



		/* define ECC layout */

		ecclayout->eccbytes		= nand_chip->ecc.bytes *

							(mtd->writesize /
@@ -2008,11 +2025,6 @@ static int omap_nand_probe(struct platform_device *pdev) 
		ecclayout->oobfree->offset	=

				ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;

		break;

#else

		pr_err("nand: error: CONFIG_MTD_NAND_OMAP_BCH not enabled\n");

		err = -EINVAL;

		goto return_error;

#endif

	default:

		pr_err("nand: error: invalid or unsupported ECC scheme\n");

		err = -EINVAL;

include/linux/platform_data/elm.h

+16 −0
Original line number Diff line number Diff line
@@ -42,8 +42,24 @@ struct elm_errorvec { 
	int error_loc[16];

};



#if IS_ENABLED(CONFIG_MTD_NAND_OMAP_BCH)

void elm_decode_bch_error_page(struct device *dev, u8 *ecc_calc,

		struct elm_errorvec *err_vec);

int elm_config(struct device *dev, enum bch_ecc bch_type,

	int ecc_steps, int ecc_step_size, int ecc_syndrome_size);

#else

static inline void

elm_decode_bch_error_page(struct device *dev, u8 *ecc_calc,

			  struct elm_errorvec *err_vec)

{

}



static inline int elm_config(struct device *dev, enum bch_ecc bch_type,

			     int ecc_steps, int ecc_step_size,

			     int ecc_syndrome_size)

{

	return -ENOSYS;

}

#endif /* CONFIG_MTD_NAND_ECC_BCH */



#endif /* __ELM_H */

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