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-rw-r--r--drivers/mtd/nand/mtk_ecc.c530
1 files changed, 530 insertions, 0 deletions
diff --git a/drivers/mtd/nand/mtk_ecc.c b/drivers/mtd/nand/mtk_ecc.c
new file mode 100644
index 0000000000000..25a4fbd4d24ae
--- /dev/null
+++ b/drivers/mtd/nand/mtk_ecc.c
@@ -0,0 +1,530 @@
+/*
+ * 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_OP_ENABLE (1)
+#define ECC_OP_DISABLE (0)
+
+#define ECC_ENCCON (0x00)
+#define ECC_ENCCNFG (0x04)
+#define ECC_CNFG_4BIT (0)
+#define ECC_CNFG_6BIT (1)
+#define ECC_CNFG_8BIT (2)
+#define ECC_CNFG_10BIT (3)
+#define ECC_CNFG_12BIT (4)
+#define ECC_CNFG_14BIT (5)
+#define ECC_CNFG_16BIT (6)
+#define ECC_CNFG_18BIT (7)
+#define ECC_CNFG_20BIT (8)
+#define ECC_CNFG_22BIT (9)
+#define ECC_CNFG_24BIT (0xa)
+#define ECC_CNFG_28BIT (0xb)
+#define ECC_CNFG_32BIT (0xc)
+#define ECC_CNFG_36BIT (0xd)
+#define ECC_CNFG_40BIT (0xe)
+#define ECC_CNFG_44BIT (0xf)
+#define ECC_CNFG_48BIT (0x10)
+#define ECC_CNFG_52BIT (0x11)
+#define ECC_CNFG_56BIT (0x12)
+#define ECC_CNFG_60BIT (0x13)
+#define ECC_MODE_SHIFT (5)
+#define ECC_MS_SHIFT (16)
+#define ECC_ENCDIADDR (0x08)
+#define ECC_ENCIDLE (0x0C)
+#define ECC_ENCPAR(x) (0x10 + (x) * sizeof(u32))
+#define ECC_ENCIRQ_EN (0x80)
+#define ECC_ENCIRQ_STA (0x84)
+#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 ERR_MASK (0x3f)
+#define ECC_DECDONE (0x124)
+#define ECC_DECIRQ_EN (0x200)
+#define ECC_DECIRQ_STA (0x204)
+
+#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)
+#define ECC_IRQ_REG(op) ((op) == ECC_ENCODE ? \
+ ECC_ENCIRQ_EN : ECC_DECIRQ_EN)
+
+struct mtk_ecc {
+ struct device *dev;
+ void __iomem *regs;
+ struct clk *clk;
+
+ struct completion done;
+ struct mutex lock;
+ u32 sectors;
+};
+
+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;
+ enum mtk_ecc_operation op;
+ u32 dec, enc;
+
+ dec = readw(ecc->regs + ECC_DECIRQ_STA) & ECC_IRQ_EN;
+ if (dec) {
+ op = ECC_DECODE;
+ dec = readw(ecc->regs + ECC_DECDONE);
+ if (dec & ecc->sectors) {
+ ecc->sectors = 0;
+ complete(&ecc->done);
+ } else {
+ return IRQ_HANDLED;
+ }
+ } else {
+ enc = readl(ecc->regs + ECC_ENCIRQ_STA) & ECC_IRQ_EN;
+ if (enc) {
+ op = ECC_ENCODE;
+ complete(&ecc->done);
+ } else {
+ return IRQ_NONE;
+ }
+ }
+
+ writel(0, ecc->regs + ECC_IRQ_REG(op));
+
+ return IRQ_HANDLED;
+}
+
+static void mtk_ecc_config(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
+{
+ u32 ecc_bit = ECC_CNFG_4BIT, dec_sz, enc_sz;
+ u32 reg;
+
+ switch (config->strength) {
+ case 4:
+ ecc_bit = ECC_CNFG_4BIT;
+ break;
+ case 6:
+ ecc_bit = ECC_CNFG_6BIT;
+ break;
+ case 8:
+ ecc_bit = ECC_CNFG_8BIT;
+ break;
+ case 10:
+ ecc_bit = ECC_CNFG_10BIT;
+ break;
+ case 12:
+ ecc_bit = ECC_CNFG_12BIT;
+ break;
+ case 14:
+ ecc_bit = ECC_CNFG_14BIT;
+ break;
+ case 16:
+ ecc_bit = ECC_CNFG_16BIT;
+ break;
+ case 18:
+ ecc_bit = ECC_CNFG_18BIT;
+ break;
+ case 20:
+ ecc_bit = ECC_CNFG_20BIT;
+ break;
+ case 22:
+ ecc_bit = ECC_CNFG_22BIT;
+ break;
+ case 24:
+ ecc_bit = ECC_CNFG_24BIT;
+ break;
+ case 28:
+ ecc_bit = ECC_CNFG_28BIT;
+ break;
+ case 32:
+ ecc_bit = ECC_CNFG_32BIT;
+ break;
+ case 36:
+ ecc_bit = ECC_CNFG_36BIT;
+ break;
+ case 40:
+ ecc_bit = ECC_CNFG_40BIT;
+ break;
+ case 44:
+ ecc_bit = ECC_CNFG_44BIT;
+ break;
+ case 48:
+ ecc_bit = ECC_CNFG_48BIT;
+ break;
+ case 52:
+ ecc_bit = ECC_CNFG_52BIT;
+ break;
+ case 56:
+ ecc_bit = ECC_CNFG_56BIT;
+ break;
+ case 60:
+ ecc_bit = ECC_CNFG_60BIT;
+ break;
+ default:
+ dev_err(ecc->dev, "invalid strength %d, default to 4 bits\n",
+ config->strength);
+ }
+
+ if (config->op == ECC_ENCODE) {
+ /* configure ECC encoder (in bits) */
+ enc_sz = config->len << 3;
+
+ reg = ecc_bit | (config->mode << 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_PARITY_BITS;
+
+ reg = ecc_bit | (config->mode << 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);
+ }
+}
+
+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 &= ERR_MASK;
+ if (err == 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;
+ 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);
+ mtk_ecc_config(ecc, config);
+ writew(ECC_OP_ENABLE, ecc->regs + ECC_CTL_REG(op));
+
+ init_completion(&ecc->done);
+ writew(ECC_IRQ_EN, ecc->regs + ECC_IRQ_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);
+ writew(0, ecc->regs + ECC_IRQ_REG(op));
+ 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 *p, len, i;
+ int ret = 0;
+
+ 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_PARITY_BITS + 7) >> 3;
+ p = (u32 *)(data + bytes);
+
+ /* write the parity bytes generated by the ECC back to the OOB region */
+ for (i = 0; i < len; i++)
+ p[i] = readl(ecc->regs + ECC_ENCPAR(i));
+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(u32 *p)
+{
+ u32 ecc[] = {4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36,
+ 40, 44, 48, 52, 56, 60};
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ecc); i++) {
+ if (*p <= ecc[i]) {
+ if (!i)
+ *p = ecc[i];
+ else if (*p != ecc[i])
+ *p = ecc[i - 1];
+ return;
+ }
+ }
+
+ *p = ecc[ARRAY_SIZE(ecc) - 1];
+}
+EXPORT_SYMBOL(mtk_ecc_adjust_strength);
+
+static int mtk_ecc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mtk_ecc *ecc;
+ struct resource *res;
+ int irq, ret;
+
+ ecc = devm_kzalloc(dev, sizeof(*ecc), GFP_KERNEL);
+ if (!ecc)
+ 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\n");
+ return -EINVAL;
+ }
+
+ 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;
+ }
+
+ mtk_ecc_hw_init(ecc);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(mtk_ecc_pm_ops, mtk_ecc_suspend, mtk_ecc_resume);
+#endif
+
+static const struct of_device_id mtk_ecc_dt_match[] = {
+ { .compatible = "mediatek,mt2701-ecc" },
+ {},
+};
+
+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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-18 08:39:07 +0000