1 files changed, 608 insertions, 0 deletions

diff --git a/drivers/mtd/nand/raw/mtk_ecc.c b/drivers/mtd/nand/raw/mtk_ecc.c
new file mode 100644
index 0000000..40d86a8
--- /dev/null
+++ b/drivers/mtd/nand/raw/mtk_ecc.c
@@ -0,0 +1,608 @@
+/*
+ * MTK ECC controller driver.
+ * Copyright (C) 2016  MediaTek Inc.
+ * Authors:	Xiaolei Li		<xiaolei.li@mediatek.com>
+ *		Jorge Ramirez-Ortiz	<jorge.ramirez-ortiz@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/mutex.h>
+
+#include "mtk_ecc.h"
+
+#define ECC_IDLE_MASK		BIT(0)
+#define ECC_IRQ_EN		BIT(0)
+#define ECC_PG_IRQ_SEL		BIT(1)
+#define ECC_OP_ENABLE		(1)
+#define ECC_OP_DISABLE		(0)
+
+#define ECC_ENCCON		(0x00)
+#define ECC_ENCCNFG		(0x04)
+#define		ECC_MS_SHIFT		(16)
+#define ECC_ENCDIADDR		(0x08)
+#define ECC_ENCIDLE		(0x0C)
+#define ECC_DECCON		(0x100)
+#define ECC_DECCNFG		(0x104)
+#define		DEC_EMPTY_EN		BIT(31)
+#define		DEC_CNFG_CORRECT	(0x3 << 12)
+#define ECC_DECIDLE		(0x10C)
+#define ECC_DECENUM0		(0x114)
+
+#define ECC_TIMEOUT		(500000)
+
+#define ECC_IDLE_REG(op)	((op) == ECC_ENCODE ? ECC_ENCIDLE : ECC_DECIDLE)
+#define ECC_CTL_REG(op)		((op) == ECC_ENCODE ? ECC_ENCCON : ECC_DECCON)
+
+struct mtk_ecc_caps {
+	u32 err_mask;
+	const u8 *ecc_strength;
+	const u32 *ecc_regs;
+	u8 num_ecc_strength;
+	u8 ecc_mode_shift;
+	u32 parity_bits;
+	int pg_irq_sel;
+};
+
+struct mtk_ecc {
+	struct device *dev;
+	const struct mtk_ecc_caps *caps;
+	void __iomem *regs;
+	struct clk *clk;
+
+	struct completion done;
+	struct mutex lock;
+	u32 sectors;
+
+	u8 *eccdata;
+};
+
+/* ecc strength that each IP supports */
+static const u8 ecc_strength_mt2701[] = {
+	4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36,
+	40, 44, 48, 52, 56, 60
+};
+
+static const u8 ecc_strength_mt2712[] = {
+	4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36,
+	40, 44, 48, 52, 56, 60, 68, 72, 80
+};
+
+static const u8 ecc_strength_mt7622[] = {
+	4, 6, 8, 10, 12, 14, 16
+};
+
+enum mtk_ecc_regs {
+	ECC_ENCPAR00,
+	ECC_ENCIRQ_EN,
+	ECC_ENCIRQ_STA,
+	ECC_DECDONE,
+	ECC_DECIRQ_EN,
+	ECC_DECIRQ_STA,
+};
+
+static int mt2701_ecc_regs[] = {
+	[ECC_ENCPAR00] =        0x10,
+	[ECC_ENCIRQ_EN] =       0x80,
+	[ECC_ENCIRQ_STA] =      0x84,
+	[ECC_DECDONE] =         0x124,
+	[ECC_DECIRQ_EN] =       0x200,
+	[ECC_DECIRQ_STA] =      0x204,
+};
+
+static int mt2712_ecc_regs[] = {
+	[ECC_ENCPAR00] =        0x300,
+	[ECC_ENCIRQ_EN] =       0x80,
+	[ECC_ENCIRQ_STA] =      0x84,
+	[ECC_DECDONE] =         0x124,
+	[ECC_DECIRQ_EN] =       0x200,
+	[ECC_DECIRQ_STA] =      0x204,
+};
+
+static int mt7622_ecc_regs[] = {
+	[ECC_ENCPAR00] =        0x10,
+	[ECC_ENCIRQ_EN] =       0x30,
+	[ECC_ENCIRQ_STA] =      0x34,
+	[ECC_DECDONE] =         0x11c,
+	[ECC_DECIRQ_EN] =       0x140,
+	[ECC_DECIRQ_STA] =      0x144,
+};
+
+static inline void mtk_ecc_wait_idle(struct mtk_ecc *ecc,
+				     enum mtk_ecc_operation op)
+{
+	struct device *dev = ecc->dev;
+	u32 val;
+	int ret;
+
+	ret = readl_poll_timeout_atomic(ecc->regs + ECC_IDLE_REG(op), val,
+					val & ECC_IDLE_MASK,
+					10, ECC_TIMEOUT);
+	if (ret)
+		dev_warn(dev, "%s NOT idle\n",
+			 op == ECC_ENCODE ? "encoder" : "decoder");
+}
+
+static irqreturn_t mtk_ecc_irq(int irq, void *id)
+{
+	struct mtk_ecc *ecc = id;
+	u32 dec, enc;
+
+	dec = readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_STA])
+		    & ECC_IRQ_EN;
+	if (dec) {
+		dec = readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECDONE]);
+		if (dec & ecc->sectors) {
+			/*
+			 * Clear decode IRQ status once again to ensure that
+			 * there will be no extra IRQ.
+			 */
+			readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_STA]);
+			ecc->sectors = 0;
+			complete(&ecc->done);
+		} else {
+			return IRQ_HANDLED;
+		}
+	} else {
+		enc = readl(ecc->regs + ecc->caps->ecc_regs[ECC_ENCIRQ_STA])
+		      & ECC_IRQ_EN;
+		if (enc)
+			complete(&ecc->done);
+		else
+			return IRQ_NONE;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int mtk_ecc_config(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
+{
+	u32 ecc_bit, dec_sz, enc_sz;
+	u32 reg, i;
+
+	for (i = 0; i < ecc->caps->num_ecc_strength; i++) {
+		if (ecc->caps->ecc_strength[i] == config->strength)
+			break;
+	}
+
+	if (i == ecc->caps->num_ecc_strength) {
+		dev_err(ecc->dev, "invalid ecc strength %d\n",
+			config->strength);
+		return -EINVAL;
+	}
+
+	ecc_bit = i;
+
+	if (config->op == ECC_ENCODE) {
+		/* configure ECC encoder (in bits) */
+		enc_sz = config->len << 3;
+
+		reg = ecc_bit | (config->mode << ecc->caps->ecc_mode_shift);
+		reg |= (enc_sz << ECC_MS_SHIFT);
+		writel(reg, ecc->regs + ECC_ENCCNFG);
+
+		if (config->mode != ECC_NFI_MODE)
+			writel(lower_32_bits(config->addr),
+			       ecc->regs + ECC_ENCDIADDR);
+
+	} else {
+		/* configure ECC decoder (in bits) */
+		dec_sz = (config->len << 3) +
+			 config->strength * ecc->caps->parity_bits;
+
+		reg = ecc_bit | (config->mode << ecc->caps->ecc_mode_shift);
+		reg |= (dec_sz << ECC_MS_SHIFT) | DEC_CNFG_CORRECT;
+		reg |= DEC_EMPTY_EN;
+		writel(reg, ecc->regs + ECC_DECCNFG);
+
+		if (config->sectors)
+			ecc->sectors = 1 << (config->sectors - 1);
+	}
+
+	return 0;
+}
+
+void mtk_ecc_get_stats(struct mtk_ecc *ecc, struct mtk_ecc_stats *stats,
+		       int sectors)
+{
+	u32 offset, i, err;
+	u32 bitflips = 0;
+
+	stats->corrected = 0;
+	stats->failed = 0;
+
+	for (i = 0; i < sectors; i++) {
+		offset = (i >> 2) << 2;
+		err = readl(ecc->regs + ECC_DECENUM0 + offset);
+		err = err >> ((i % 4) * 8);
+		err &= ecc->caps->err_mask;
+		if (err == ecc->caps->err_mask) {
+			/* uncorrectable errors */
+			stats->failed++;
+			continue;
+		}
+
+		stats->corrected += err;
+		bitflips = max_t(u32, bitflips, err);
+	}
+
+	stats->bitflips = bitflips;
+}
+EXPORT_SYMBOL(mtk_ecc_get_stats);
+
+void mtk_ecc_release(struct mtk_ecc *ecc)
+{
+	clk_disable_unprepare(ecc->clk);
+	put_device(ecc->dev);
+}
+EXPORT_SYMBOL(mtk_ecc_release);
+
+static void mtk_ecc_hw_init(struct mtk_ecc *ecc)
+{
+	mtk_ecc_wait_idle(ecc, ECC_ENCODE);
+	writew(ECC_OP_DISABLE, ecc->regs + ECC_ENCCON);
+
+	mtk_ecc_wait_idle(ecc, ECC_DECODE);
+	writel(ECC_OP_DISABLE, ecc->regs + ECC_DECCON);
+}
+
+static struct mtk_ecc *mtk_ecc_get(struct device_node *np)
+{
+	struct platform_device *pdev;
+	struct mtk_ecc *ecc;
+
+	pdev = of_find_device_by_node(np);
+	if (!pdev || !platform_get_drvdata(pdev))
+		return ERR_PTR(-EPROBE_DEFER);
+
+	get_device(&pdev->dev);
+	ecc = platform_get_drvdata(pdev);
+	clk_prepare_enable(ecc->clk);
+	mtk_ecc_hw_init(ecc);
+
+	return ecc;
+}
+
+struct mtk_ecc *of_mtk_ecc_get(struct device_node *of_node)
+{
+	struct mtk_ecc *ecc = NULL;
+	struct device_node *np;
+
+	np = of_parse_phandle(of_node, "ecc-engine", 0);
+	if (np) {
+		ecc = mtk_ecc_get(np);
+		of_node_put(np);
+	}
+
+	return ecc;
+}
+EXPORT_SYMBOL(of_mtk_ecc_get);
+
+int mtk_ecc_enable(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
+{
+	enum mtk_ecc_operation op = config->op;
+	u16 reg_val;
+	int ret;
+
+	ret = mutex_lock_interruptible(&ecc->lock);
+	if (ret) {
+		dev_err(ecc->dev, "interrupted when attempting to lock\n");
+		return ret;
+	}
+
+	mtk_ecc_wait_idle(ecc, op);
+
+	ret = mtk_ecc_config(ecc, config);
+	if (ret) {
+		mutex_unlock(&ecc->lock);
+		return ret;
+	}
+
+	if (config->mode != ECC_NFI_MODE || op != ECC_ENCODE) {
+		init_completion(&ecc->done);
+		reg_val = ECC_IRQ_EN;
+		/*
+		 * For ECC_NFI_MODE, if ecc->caps->pg_irq_sel is 1, then it
+		 * means this chip can only generate one ecc irq during page
+		 * read / write. If is 0, generate one ecc irq each ecc step.
+		 */
+		if (ecc->caps->pg_irq_sel && config->mode == ECC_NFI_MODE)
+			reg_val |= ECC_PG_IRQ_SEL;
+		if (op == ECC_ENCODE)
+			writew(reg_val, ecc->regs +
+			       ecc->caps->ecc_regs[ECC_ENCIRQ_EN]);
+		else
+			writew(reg_val, ecc->regs +
+			       ecc->caps->ecc_regs[ECC_DECIRQ_EN]);
+	}
+
+	writew(ECC_OP_ENABLE, ecc->regs + ECC_CTL_REG(op));
+
+	return 0;
+}
+EXPORT_SYMBOL(mtk_ecc_enable);
+
+void mtk_ecc_disable(struct mtk_ecc *ecc)
+{
+	enum mtk_ecc_operation op = ECC_ENCODE;
+
+	/* find out the running operation */
+	if (readw(ecc->regs + ECC_CTL_REG(op)) != ECC_OP_ENABLE)
+		op = ECC_DECODE;
+
+	/* disable it */
+	mtk_ecc_wait_idle(ecc, op);
+	if (op == ECC_DECODE) {
+		/*
+		 * Clear decode IRQ status in case there is a timeout to wait
+		 * decode IRQ.
+		 */
+		readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECDONE]);
+		writew(0, ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_EN]);
+	} else {
+		writew(0, ecc->regs + ecc->caps->ecc_regs[ECC_ENCIRQ_EN]);
+	}
+
+	writew(ECC_OP_DISABLE, ecc->regs + ECC_CTL_REG(op));
+
+	mutex_unlock(&ecc->lock);
+}
+EXPORT_SYMBOL(mtk_ecc_disable);
+
+int mtk_ecc_wait_done(struct mtk_ecc *ecc, enum mtk_ecc_operation op)
+{
+	int ret;
+
+	ret = wait_for_completion_timeout(&ecc->done, msecs_to_jiffies(500));
+	if (!ret) {
+		dev_err(ecc->dev, "%s timeout - interrupt did not arrive)\n",
+			(op == ECC_ENCODE) ? "encoder" : "decoder");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(mtk_ecc_wait_done);
+
+int mtk_ecc_encode(struct mtk_ecc *ecc, struct mtk_ecc_config *config,
+		   u8 *data, u32 bytes)
+{
+	dma_addr_t addr;
+	u32 len;
+	int ret;
+
+	addr = dma_map_single(ecc->dev, data, bytes, DMA_TO_DEVICE);
+	ret = dma_mapping_error(ecc->dev, addr);
+	if (ret) {
+		dev_err(ecc->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+
+	config->op = ECC_ENCODE;
+	config->addr = addr;
+	ret = mtk_ecc_enable(ecc, config);
+	if (ret) {
+		dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
+		return ret;
+	}
+
+	ret = mtk_ecc_wait_done(ecc, ECC_ENCODE);
+	if (ret)
+		goto timeout;
+
+	mtk_ecc_wait_idle(ecc, ECC_ENCODE);
+
+	/* Program ECC bytes to OOB: per sector oob = FDM + ECC + SPARE */
+	len = (config->strength * ecc->caps->parity_bits + 7) >> 3;
+
+	/* write the parity bytes generated by the ECC back to temp buffer */
+	__ioread32_copy(ecc->eccdata,
+			ecc->regs + ecc->caps->ecc_regs[ECC_ENCPAR00],
+			round_up(len, 4));
+
+	/* copy into possibly unaligned OOB region with actual length */
+	memcpy(data + bytes, ecc->eccdata, len);
+timeout:
+
+	dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
+	mtk_ecc_disable(ecc);
+
+	return ret;
+}
+EXPORT_SYMBOL(mtk_ecc_encode);
+
+void mtk_ecc_adjust_strength(struct mtk_ecc *ecc, u32 *p)
+{
+	const u8 *ecc_strength = ecc->caps->ecc_strength;
+	int i;
+
+	for (i = 0; i < ecc->caps->num_ecc_strength; i++) {
+		if (*p <= ecc_strength[i]) {
+			if (!i)
+				*p = ecc_strength[i];
+			else if (*p != ecc_strength[i])
+				*p = ecc_strength[i - 1];
+			return;
+		}
+	}
+
+	*p = ecc_strength[ecc->caps->num_ecc_strength - 1];
+}
+EXPORT_SYMBOL(mtk_ecc_adjust_strength);
+
+unsigned int mtk_ecc_get_parity_bits(struct mtk_ecc *ecc)
+{
+	return ecc->caps->parity_bits;
+}
+EXPORT_SYMBOL(mtk_ecc_get_parity_bits);
+
+static const struct mtk_ecc_caps mtk_ecc_caps_mt2701 = {
+	.err_mask = 0x3f,
+	.ecc_strength = ecc_strength_mt2701,
+	.ecc_regs = mt2701_ecc_regs,
+	.num_ecc_strength = 20,
+	.ecc_mode_shift = 5,
+	.parity_bits = 14,
+	.pg_irq_sel = 0,
+};
+
+static const struct mtk_ecc_caps mtk_ecc_caps_mt2712 = {
+	.err_mask = 0x7f,
+	.ecc_strength = ecc_strength_mt2712,
+	.ecc_regs = mt2712_ecc_regs,
+	.num_ecc_strength = 23,
+	.ecc_mode_shift = 5,
+	.parity_bits = 14,
+	.pg_irq_sel = 1,
+};
+
+static const struct mtk_ecc_caps mtk_ecc_caps_mt7622 = {
+	.err_mask = 0x3f,
+	.ecc_strength = ecc_strength_mt7622,
+	.ecc_regs = mt7622_ecc_regs,
+	.num_ecc_strength = 7,
+	.ecc_mode_shift = 4,
+	.parity_bits = 13,
+	.pg_irq_sel = 0,
+};
+
+static const struct of_device_id mtk_ecc_dt_match[] = {
+	{
+		.compatible = "mediatek,mt2701-ecc",
+		.data = &mtk_ecc_caps_mt2701,
+	}, {
+		.compatible = "mediatek,mt2712-ecc",
+		.data = &mtk_ecc_caps_mt2712,
+	}, {
+		.compatible = "mediatek,mt7622-ecc",
+		.data = &mtk_ecc_caps_mt7622,
+	},
+	{},
+};
+
+static int mtk_ecc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtk_ecc *ecc;
+	struct resource *res;
+	const struct of_device_id *of_ecc_id = NULL;
+	u32 max_eccdata_size;
+	int irq, ret;
+
+	ecc = devm_kzalloc(dev, sizeof(*ecc), GFP_KERNEL);
+	if (!ecc)
+		return -ENOMEM;
+
+	of_ecc_id = of_match_device(mtk_ecc_dt_match, &pdev->dev);
+	if (!of_ecc_id)
+		return -ENODEV;
+
+	ecc->caps = of_ecc_id->data;
+
+	max_eccdata_size = ecc->caps->num_ecc_strength - 1;
+	max_eccdata_size = ecc->caps->ecc_strength[max_eccdata_size];
+	max_eccdata_size = (max_eccdata_size * ecc->caps->parity_bits + 7) >> 3;
+	max_eccdata_size = round_up(max_eccdata_size, 4);
+	ecc->eccdata = devm_kzalloc(dev, max_eccdata_size, GFP_KERNEL);
+	if (!ecc->eccdata)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ecc->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(ecc->regs)) {
+		dev_err(dev, "failed to map regs: %ld\n", PTR_ERR(ecc->regs));
+		return PTR_ERR(ecc->regs);
+	}
+
+	ecc->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(ecc->clk)) {
+		dev_err(dev, "failed to get clock: %ld\n", PTR_ERR(ecc->clk));
+		return PTR_ERR(ecc->clk);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "failed to get irq: %d\n", irq);
+		return irq;
+	}
+
+	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dev, "failed to set DMA mask\n");
+		return ret;
+	}
+
+	ret = devm_request_irq(dev, irq, mtk_ecc_irq, 0x0, "mtk-ecc", ecc);
+	if (ret) {
+		dev_err(dev, "failed to request irq\n");
+		return -EINVAL;
+	}
+
+	ecc->dev = dev;
+	mutex_init(&ecc->lock);
+	platform_set_drvdata(pdev, ecc);
+	dev_info(dev, "probed\n");
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mtk_ecc_suspend(struct device *dev)
+{
+	struct mtk_ecc *ecc = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(ecc->clk);
+
+	return 0;
+}
+
+static int mtk_ecc_resume(struct device *dev)
+{
+	struct mtk_ecc *ecc = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(ecc->clk);
+	if (ret) {
+		dev_err(dev, "failed to enable clk\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(mtk_ecc_pm_ops, mtk_ecc_suspend, mtk_ecc_resume);
+#endif
+
+MODULE_DEVICE_TABLE(of, mtk_ecc_dt_match);
+
+static struct platform_driver mtk_ecc_driver = {
+	.probe  = mtk_ecc_probe,
+	.driver = {
+		.name  = "mtk-ecc",
+		.of_match_table = of_match_ptr(mtk_ecc_dt_match),
+#ifdef CONFIG_PM_SLEEP
+		.pm = &mtk_ecc_pm_ops,
+#endif
+	},
+};
+
+module_platform_driver(mtk_ecc_driver);
+
+MODULE_AUTHOR("Xiaolei Li <xiaolei.li@mediatek.com>");
+MODULE_DESCRIPTION("MTK Nand ECC Driver");
+MODULE_LICENSE("GPL");