drivers/mtd/nand/raw/ingenic/jz4725b_bch.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * JZ4725B BCH controller driver
  *
  * Copyright (C) 2019 Paul Cercueil <paul@crapouillou.net>
  *
  * Based on jz4780_bch.c
  */

 #include <linux/bitops.h>
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>

 #include "ingenic_ecc.h"

 #define BCH_BHCR			0x0
 #define BCH_BHCSR			0x4
 #define BCH_BHCCR			0x8
 #define BCH_BHCNT			0xc
 #define BCH_BHDR			0x10
 #define BCH_BHPAR0			0x14
 #define BCH_BHERR0			0x28
 #define BCH_BHINT			0x24
 #define BCH_BHINTES			0x3c
 #define BCH_BHINTEC			0x40
 #define BCH_BHINTE			0x38

 #define BCH_BHCR_ENCE			BIT(3)
 #define BCH_BHCR_BSEL			BIT(2)
 #define BCH_BHCR_INIT			BIT(1)
 #define BCH_BHCR_BCHE			BIT(0)

 #define BCH_BHCNT_DEC_COUNT_SHIFT	16
 #define BCH_BHCNT_DEC_COUNT_MASK	(0x3ff << BCH_BHCNT_DEC_COUNT_SHIFT)
 #define BCH_BHCNT_ENC_COUNT_SHIFT	0
 #define BCH_BHCNT_ENC_COUNT_MASK	(0x3ff << BCH_BHCNT_ENC_COUNT_SHIFT)

 #define BCH_BHERR_INDEX0_SHIFT		0
 #define BCH_BHERR_INDEX0_MASK		(0x1fff << BCH_BHERR_INDEX0_SHIFT)
 #define BCH_BHERR_INDEX1_SHIFT		16
 #define BCH_BHERR_INDEX1_MASK		(0x1fff << BCH_BHERR_INDEX1_SHIFT)

 #define BCH_BHINT_ERRC_SHIFT		28
 #define BCH_BHINT_ERRC_MASK		(0xf << BCH_BHINT_ERRC_SHIFT)
 #define BCH_BHINT_TERRC_SHIFT		16
 #define BCH_BHINT_TERRC_MASK		(0x7f << BCH_BHINT_TERRC_SHIFT)
 #define BCH_BHINT_ALL_0			BIT(5)
 #define BCH_BHINT_ALL_F			BIT(4)
 #define BCH_BHINT_DECF			BIT(3)
 #define BCH_BHINT_ENCF			BIT(2)
 #define BCH_BHINT_UNCOR			BIT(1)
 #define BCH_BHINT_ERR			BIT(0)

 /* Timeout for BCH calculation/correction. */
 #define BCH_TIMEOUT_US			100000

 static inline void jz4725b_bch_config_set(struct ingenic_ecc *bch, u32 cfg)
 {
 	writel(cfg, bch->base + BCH_BHCSR);
 }

 static inline void jz4725b_bch_config_clear(struct ingenic_ecc *bch, u32 cfg)
 {
 	writel(cfg, bch->base + BCH_BHCCR);
 }

 static int jz4725b_bch_reset(struct ingenic_ecc *bch,
 			     struct ingenic_ecc_params *params, bool calc_ecc)
 {
 	u32 reg, max_value;

 	/* Clear interrupt status. */
 	writel(readl(bch->base + BCH_BHINT), bch->base + BCH_BHINT);

 	/* Initialise and enable BCH. */
 	jz4725b_bch_config_clear(bch, 0x1f);
 	jz4725b_bch_config_set(bch, BCH_BHCR_BCHE);

 	if (params->strength == 8)
 		jz4725b_bch_config_set(bch, BCH_BHCR_BSEL);
 	else
 		jz4725b_bch_config_clear(bch, BCH_BHCR_BSEL);

 	if (calc_ecc) /* calculate ECC from data */
 		jz4725b_bch_config_set(bch, BCH_BHCR_ENCE);
 	else /* correct data from ECC */
 		jz4725b_bch_config_clear(bch, BCH_BHCR_ENCE);

 	jz4725b_bch_config_set(bch, BCH_BHCR_INIT);

 	max_value = BCH_BHCNT_ENC_COUNT_MASK >> BCH_BHCNT_ENC_COUNT_SHIFT;
 	if (params->size > max_value)
 		return -EINVAL;

 	max_value = BCH_BHCNT_DEC_COUNT_MASK >> BCH_BHCNT_DEC_COUNT_SHIFT;
 	if (params->size + params->bytes > max_value)
 		return -EINVAL;

 	/* Set up BCH count register. */
 	reg = params->size << BCH_BHCNT_ENC_COUNT_SHIFT;
 	reg |= (params->size + params->bytes) << BCH_BHCNT_DEC_COUNT_SHIFT;
 	writel(reg, bch->base + BCH_BHCNT);

 	return 0;
 }

 static void jz4725b_bch_disable(struct ingenic_ecc *bch)
 {
 	/* Clear interrupts */
 	writel(readl(bch->base + BCH_BHINT), bch->base + BCH_BHINT);

 	/* Disable the hardware */
 	jz4725b_bch_config_clear(bch, BCH_BHCR_BCHE);
 }

 static void jz4725b_bch_write_data(struct ingenic_ecc *bch, const u8 *buf,
 				   size_t size)
 {
 	while (size--)
 		writeb(*buf++, bch->base + BCH_BHDR);
 }

 static void jz4725b_bch_read_parity(struct ingenic_ecc *bch, u8 *buf,
 				    size_t size)
 {
 	size_t size32 = size / sizeof(u32);
 	size_t size8 = size % sizeof(u32);
 	u32 *dest32;
 	u8 *dest8;
 	u32 val, offset = 0;

 	dest32 = (u32 *)buf;
 	while (size32--) {
 		*dest32++ = readl_relaxed(bch->base + BCH_BHPAR0 + offset);
 		offset += sizeof(u32);
 	}

 	dest8 = (u8 *)dest32;
 	val = readl_relaxed(bch->base + BCH_BHPAR0 + offset);
 	switch (size8) {
 	case 3:
 		dest8[2] = (val >> 16) & 0xff;
 		fallthrough;
 	case 2:
 		dest8[1] = (val >> 8) & 0xff;
 		fallthrough;
 	case 1:
 		dest8[0] = val & 0xff;
 		break;
 	}
 }

 static int jz4725b_bch_wait_complete(struct ingenic_ecc *bch, unsigned int irq,
 				     u32 *status)
 {
 	u32 reg;
 	int ret;

 	/*
 	 * While we could use interrupts here and sleep until the operation
 	 * completes, the controller works fairly quickly (usually a few
 	 * microseconds) and so the overhead of sleeping until we get an
 	 * interrupt quite noticeably decreases performance.
 	 */
 	ret = readl_relaxed_poll_timeout(bch->base + BCH_BHINT, reg,
 					 reg & irq, 0, BCH_TIMEOUT_US);
 	if (ret)
 		return ret;

 	if (status)
 		*status = reg;

 	writel(reg, bch->base + BCH_BHINT);

 	return 0;
 }

 static int jz4725b_calculate(struct ingenic_ecc *bch,
 			     struct ingenic_ecc_params *params,
 			     const u8 *buf, u8 *ecc_code)
 {
 	int ret;

 	mutex_lock(&bch->lock);

 	ret = jz4725b_bch_reset(bch, params, true);
 	if (ret) {
 		dev_err(bch->dev, "Unable to init BCH with given parameters\n");
 		goto out_disable;
 	}

 	jz4725b_bch_write_data(bch, buf, params->size);

 	ret = jz4725b_bch_wait_complete(bch, BCH_BHINT_ENCF, NULL);
 	if (ret) {
 		dev_err(bch->dev, "timed out while calculating ECC\n");
 		goto out_disable;
 	}

 	jz4725b_bch_read_parity(bch, ecc_code, params->bytes);

 out_disable:
 	jz4725b_bch_disable(bch);
 	mutex_unlock(&bch->lock);

 	return ret;
 }

 static int jz4725b_correct(struct ingenic_ecc *bch,
 			   struct ingenic_ecc_params *params,
 			   u8 *buf, u8 *ecc_code)
 {
 	u32 reg, errors, bit;
 	unsigned int i;
 	int ret;

 	mutex_lock(&bch->lock);

 	ret = jz4725b_bch_reset(bch, params, false);
 	if (ret) {
 		dev_err(bch->dev, "Unable to init BCH with given parameters\n");
 		goto out;
 	}

 	jz4725b_bch_write_data(bch, buf, params->size);
 	jz4725b_bch_write_data(bch, ecc_code, params->bytes);

 	ret = jz4725b_bch_wait_complete(bch, BCH_BHINT_DECF, &reg);
 	if (ret) {
 		dev_err(bch->dev, "timed out while correcting data\n");
 		goto out;
 	}

 	if (reg & (BCH_BHINT_ALL_F | BCH_BHINT_ALL_0)) {
 		/* Data and ECC is all 0xff or 0x00 - nothing to correct */
 		ret = 0;
 		goto out;
 	}

 	if (reg & BCH_BHINT_UNCOR) {
 		/* Uncorrectable ECC error */
 		ret = -EBADMSG;
 		goto out;
 	}

 	errors = (reg & BCH_BHINT_ERRC_MASK) >> BCH_BHINT_ERRC_SHIFT;

 	/* Correct any detected errors. */
 	for (i = 0; i < errors; i++) {
 		if (i & 1) {
 			bit = (reg & BCH_BHERR_INDEX1_MASK) >> BCH_BHERR_INDEX1_SHIFT;
 		} else {
 			reg = readl(bch->base + BCH_BHERR0 + (i * 4));
 			bit = (reg & BCH_BHERR_INDEX0_MASK) >> BCH_BHERR_INDEX0_SHIFT;
 		}

 		buf[(bit >> 3)] ^= BIT(bit & 0x7);
 	}

 out:
 	jz4725b_bch_disable(bch);
 	mutex_unlock(&bch->lock);

 	return ret;
 }

 static const struct ingenic_ecc_ops jz4725b_bch_ops = {
 	.disable = jz4725b_bch_disable,
 	.calculate = jz4725b_calculate,
 	.correct = jz4725b_correct,
 };

 static const struct of_device_id jz4725b_bch_dt_match[] = {
 	{ .compatible = "ingenic,jz4725b-bch", .data = &jz4725b_bch_ops },
 	{},
 };
 MODULE_DEVICE_TABLE(of, jz4725b_bch_dt_match);

 static struct platform_driver jz4725b_bch_driver = {
 	.probe		= ingenic_ecc_probe,
 	.driver	= {
 		.name	= "jz4725b-bch",
 		.of_match_table = jz4725b_bch_dt_match,
 	},
 };
 module_platform_driver(jz4725b_bch_driver);

 MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
 MODULE_DESCRIPTION("Ingenic JZ4725B BCH controller driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* JZ4725B BCH controller driver
	*
	* Copyright (C) 2019 Paul Cercueil <paul@crapouillou.net>
	*
	* Based on jz4780_bch.c
	*/

	#include <linux/bitops.h>
	#include <linux/device.h>
	#include <linux/io.h>
	#include <linux/iopoll.h>
	#include <linux/module.h>
	#include <linux/mutex.h>
	#include <linux/of_platform.h>
	#include <linux/platform_device.h>

	#include "ingenic_ecc.h"

	#define BCH_BHCR 0x0
	#define BCH_BHCSR 0x4
	#define BCH_BHCCR 0x8
	#define BCH_BHCNT 0xc
	#define BCH_BHDR 0x10
	#define BCH_BHPAR0 0x14
	#define BCH_BHERR0 0x28
	#define BCH_BHINT 0x24
	#define BCH_BHINTES 0x3c
	#define BCH_BHINTEC 0x40
	#define BCH_BHINTE 0x38

	#define BCH_BHCR_ENCE BIT(3)
	#define BCH_BHCR_BSEL BIT(2)
	#define BCH_BHCR_INIT BIT(1)
	#define BCH_BHCR_BCHE BIT(0)

	#define BCH_BHCNT_DEC_COUNT_SHIFT 16
	#define BCH_BHCNT_DEC_COUNT_MASK (0x3ff << BCH_BHCNT_DEC_COUNT_SHIFT)
	#define BCH_BHCNT_ENC_COUNT_SHIFT 0
	#define BCH_BHCNT_ENC_COUNT_MASK (0x3ff << BCH_BHCNT_ENC_COUNT_SHIFT)

	#define BCH_BHERR_INDEX0_SHIFT 0
	#define BCH_BHERR_INDEX0_MASK (0x1fff << BCH_BHERR_INDEX0_SHIFT)
	#define BCH_BHERR_INDEX1_SHIFT 16
	#define BCH_BHERR_INDEX1_MASK (0x1fff << BCH_BHERR_INDEX1_SHIFT)

	#define BCH_BHINT_ERRC_SHIFT 28
	#define BCH_BHINT_ERRC_MASK (0xf << BCH_BHINT_ERRC_SHIFT)
	#define BCH_BHINT_TERRC_SHIFT 16
	#define BCH_BHINT_TERRC_MASK (0x7f << BCH_BHINT_TERRC_SHIFT)
	#define BCH_BHINT_ALL_0 BIT(5)
	#define BCH_BHINT_ALL_F BIT(4)
	#define BCH_BHINT_DECF BIT(3)
	#define BCH_BHINT_ENCF BIT(2)
	#define BCH_BHINT_UNCOR BIT(1)
	#define BCH_BHINT_ERR BIT(0)

	/* Timeout for BCH calculation/correction. */
	#define BCH_TIMEOUT_US 100000

	static inline void jz4725b_bch_config_set(struct ingenic_ecc *bch, u32 cfg)
	{
	writel(cfg, bch->base + BCH_BHCSR);
	}

	static inline void jz4725b_bch_config_clear(struct ingenic_ecc *bch, u32 cfg)
	{
	writel(cfg, bch->base + BCH_BHCCR);
	}

	static int jz4725b_bch_reset(struct ingenic_ecc *bch,
	struct ingenic_ecc_params *params, bool calc_ecc)
	{
	u32 reg, max_value;

	/* Clear interrupt status. */
	writel(readl(bch->base + BCH_BHINT), bch->base + BCH_BHINT);

	/* Initialise and enable BCH. */
	jz4725b_bch_config_clear(bch, 0x1f);
	jz4725b_bch_config_set(bch, BCH_BHCR_BCHE);

	if (params->strength == 8)
	jz4725b_bch_config_set(bch, BCH_BHCR_BSEL);
	else
	jz4725b_bch_config_clear(bch, BCH_BHCR_BSEL);

	if (calc_ecc) /* calculate ECC from data */
	jz4725b_bch_config_set(bch, BCH_BHCR_ENCE);
	else /* correct data from ECC */
	jz4725b_bch_config_clear(bch, BCH_BHCR_ENCE);

	jz4725b_bch_config_set(bch, BCH_BHCR_INIT);

	max_value = BCH_BHCNT_ENC_COUNT_MASK >> BCH_BHCNT_ENC_COUNT_SHIFT;
	if (params->size > max_value)
	return -EINVAL;

	max_value = BCH_BHCNT_DEC_COUNT_MASK >> BCH_BHCNT_DEC_COUNT_SHIFT;
	if (params->size + params->bytes > max_value)
	return -EINVAL;

	/* Set up BCH count register. */
	reg = params->size << BCH_BHCNT_ENC_COUNT_SHIFT;
	reg \|= (params->size + params->bytes) << BCH_BHCNT_DEC_COUNT_SHIFT;
	writel(reg, bch->base + BCH_BHCNT);

	return 0;
	}

	static void jz4725b_bch_disable(struct ingenic_ecc *bch)
	{
	/* Clear interrupts */
	writel(readl(bch->base + BCH_BHINT), bch->base + BCH_BHINT);

	/* Disable the hardware */
	jz4725b_bch_config_clear(bch, BCH_BHCR_BCHE);
	}

	static void jz4725b_bch_write_data(struct ingenic_ecc bch, const u8 buf,
	size_t size)
	{
	while (size--)
	writeb(*buf++, bch->base + BCH_BHDR);
	}

	static void jz4725b_bch_read_parity(struct ingenic_ecc bch, u8 buf,
	size_t size)
	{
	size_t size32 = size / sizeof(u32);
	size_t size8 = size % sizeof(u32);
	u32 *dest32;
	u8 *dest8;
	u32 val, offset = 0;

	dest32 = (u32 *)buf;
	while (size32--) {
	*dest32++ = readl_relaxed(bch->base + BCH_BHPAR0 + offset);
	offset += sizeof(u32);
	}

	dest8 = (u8 *)dest32;
	val = readl_relaxed(bch->base + BCH_BHPAR0 + offset);
	switch (size8) {
	case 3:
	dest8[2] = (val >> 16) & 0xff;
	fallthrough;
	case 2:
	dest8[1] = (val >> 8) & 0xff;
	fallthrough;
	case 1:
	dest8[0] = val & 0xff;
	break;
	}
	}

	static int jz4725b_bch_wait_complete(struct ingenic_ecc *bch, unsigned int irq,
	u32 *status)
	{
	u32 reg;
	int ret;

	/*
	* While we could use interrupts here and sleep until the operation
	* completes, the controller works fairly quickly (usually a few
	* microseconds) and so the overhead of sleeping until we get an
	* interrupt quite noticeably decreases performance.
	*/
	ret = readl_relaxed_poll_timeout(bch->base + BCH_BHINT, reg,
	reg & irq, 0, BCH_TIMEOUT_US);
	if (ret)
	return ret;

	if (status)
	*status = reg;

	writel(reg, bch->base + BCH_BHINT);

	return 0;
	}

	static int jz4725b_calculate(struct ingenic_ecc *bch,
	struct ingenic_ecc_params *params,
	const u8 buf, u8 ecc_code)
	{
	int ret;

	mutex_lock(&bch->lock);

	ret = jz4725b_bch_reset(bch, params, true);
	if (ret) {
	dev_err(bch->dev, "Unable to init BCH with given parameters\n");
	goto out_disable;
	}

	jz4725b_bch_write_data(bch, buf, params->size);

	ret = jz4725b_bch_wait_complete(bch, BCH_BHINT_ENCF, NULL);
	if (ret) {
	dev_err(bch->dev, "timed out while calculating ECC\n");
	goto out_disable;
	}

	jz4725b_bch_read_parity(bch, ecc_code, params->bytes);

	out_disable:
	jz4725b_bch_disable(bch);
	mutex_unlock(&bch->lock);

	return ret;
	}

	static int jz4725b_correct(struct ingenic_ecc *bch,
	struct ingenic_ecc_params *params,
	u8 buf, u8 ecc_code)
	{
	u32 reg, errors, bit;
	unsigned int i;
	int ret;

	mutex_lock(&bch->lock);

	ret = jz4725b_bch_reset(bch, params, false);
	if (ret) {
	dev_err(bch->dev, "Unable to init BCH with given parameters\n");
	goto out;
	}

	jz4725b_bch_write_data(bch, buf, params->size);
	jz4725b_bch_write_data(bch, ecc_code, params->bytes);

	ret = jz4725b_bch_wait_complete(bch, BCH_BHINT_DECF, &reg);
	if (ret) {
	dev_err(bch->dev, "timed out while correcting data\n");
	goto out;
	}

	if (reg & (BCH_BHINT_ALL_F \| BCH_BHINT_ALL_0)) {
	/* Data and ECC is all 0xff or 0x00 - nothing to correct */
	ret = 0;
	goto out;
	}

	if (reg & BCH_BHINT_UNCOR) {
	/* Uncorrectable ECC error */
	ret = -EBADMSG;
	goto out;
	}

	errors = (reg & BCH_BHINT_ERRC_MASK) >> BCH_BHINT_ERRC_SHIFT;

	/* Correct any detected errors. */
	for (i = 0; i < errors; i++) {
	if (i & 1) {
	bit = (reg & BCH_BHERR_INDEX1_MASK) >> BCH_BHERR_INDEX1_SHIFT;
	} else {
	reg = readl(bch->base + BCH_BHERR0 + (i * 4));
	bit = (reg & BCH_BHERR_INDEX0_MASK) >> BCH_BHERR_INDEX0_SHIFT;
	}

	buf[(bit >> 3)] ^= BIT(bit & 0x7);
	}

	out:
	jz4725b_bch_disable(bch);
	mutex_unlock(&bch->lock);

	return ret;
	}

	static const struct ingenic_ecc_ops jz4725b_bch_ops = {
	.disable = jz4725b_bch_disable,
	.calculate = jz4725b_calculate,
	.correct = jz4725b_correct,
	};

	static const struct of_device_id jz4725b_bch_dt_match[] = {
	{ .compatible = "ingenic,jz4725b-bch", .data = &jz4725b_bch_ops },
	{},
	};
	MODULE_DEVICE_TABLE(of, jz4725b_bch_dt_match);

	static struct platform_driver jz4725b_bch_driver = {
	.probe = ingenic_ecc_probe,
	.driver = {
	.name = "jz4725b-bch",
	.of_match_table = jz4725b_bch_dt_match,
	},
	};
	module_platform_driver(jz4725b_bch_driver);

	MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
	MODULE_DESCRIPTION("Ingenic JZ4725B BCH controller driver");
	MODULE_LICENSE("GPL v2");