diff options
Diffstat (limited to 'drivers/mtd/nand/raw/mtk_ecc.c')
-rw-r--r-- | drivers/mtd/nand/raw/mtk_ecc.c | 608 |
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"); |