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Diffstat (limited to 'drivers/mtd/nand/raw/mtk_ecc.c')
-rw-r--r--drivers/mtd/nand/raw/mtk_ecc.c608
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 000000000000..40d86a861a70
--- /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");