diff options
Diffstat (limited to 'drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c')
| -rw-r--r-- | drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c | 943 |
1 files changed, 943 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c new file mode 100644 index 0000000..e945567 --- /dev/null +++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c @@ -0,0 +1,943 @@ +/* + * Freescale GPMI NAND Flash Driver + * + * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. + * Copyright (C) 2008 Embedded Alley Solutions, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/slab.h> + +#include "gpmi-nand.h" +#include "gpmi-regs.h" +#include "bch-regs.h" + +/* Converts time to clock cycles */ +#define TO_CYCLES(duration, period) DIV_ROUND_UP_ULL(duration, period) + +#define MXS_SET_ADDR 0x4 +#define MXS_CLR_ADDR 0x8 +/* + * Clear the bit and poll it cleared. This is usually called with + * a reset address and mask being either SFTRST(bit 31) or CLKGATE + * (bit 30). + */ +static int clear_poll_bit(void __iomem *addr, u32 mask) +{ + int timeout = 0x400; + + /* clear the bit */ + writel(mask, addr + MXS_CLR_ADDR); + + /* + * SFTRST needs 3 GPMI clocks to settle, the reference manual + * recommends to wait 1us. + */ + udelay(1); + + /* poll the bit becoming clear */ + while ((readl(addr) & mask) && --timeout) + /* nothing */; + + return !timeout; +} + +#define MODULE_CLKGATE (1 << 30) +#define MODULE_SFTRST (1 << 31) +/* + * The current mxs_reset_block() will do two things: + * [1] enable the module. + * [2] reset the module. + * + * In most of the cases, it's ok. + * But in MX23, there is a hardware bug in the BCH block (see erratum #2847). + * If you try to soft reset the BCH block, it becomes unusable until + * the next hard reset. This case occurs in the NAND boot mode. When the board + * boots by NAND, the ROM of the chip will initialize the BCH blocks itself. + * So If the driver tries to reset the BCH again, the BCH will not work anymore. + * You will see a DMA timeout in this case. The bug has been fixed + * in the following chips, such as MX28. + * + * To avoid this bug, just add a new parameter `just_enable` for + * the mxs_reset_block(), and rewrite it here. + */ +static int gpmi_reset_block(void __iomem *reset_addr, bool just_enable) +{ + int ret; + int timeout = 0x400; + + /* clear and poll SFTRST */ + ret = clear_poll_bit(reset_addr, MODULE_SFTRST); + if (unlikely(ret)) + goto error; + + /* clear CLKGATE */ + writel(MODULE_CLKGATE, reset_addr + MXS_CLR_ADDR); + + if (!just_enable) { + /* set SFTRST to reset the block */ + writel(MODULE_SFTRST, reset_addr + MXS_SET_ADDR); + udelay(1); + + /* poll CLKGATE becoming set */ + while ((!(readl(reset_addr) & MODULE_CLKGATE)) && --timeout) + /* nothing */; + if (unlikely(!timeout)) + goto error; + } + + /* clear and poll SFTRST */ + ret = clear_poll_bit(reset_addr, MODULE_SFTRST); + if (unlikely(ret)) + goto error; + + /* clear and poll CLKGATE */ + ret = clear_poll_bit(reset_addr, MODULE_CLKGATE); + if (unlikely(ret)) + goto error; + + return 0; + +error: + pr_err("%s(%p): module reset timeout\n", __func__, reset_addr); + return -ETIMEDOUT; +} + +static int __gpmi_enable_clk(struct gpmi_nand_data *this, bool v) +{ + struct clk *clk; + int ret; + int i; + + for (i = 0; i < GPMI_CLK_MAX; i++) { + clk = this->resources.clock[i]; + if (!clk) + break; + + if (v) { + ret = clk_prepare_enable(clk); + if (ret) + goto err_clk; + } else { + clk_disable_unprepare(clk); + } + } + return 0; + +err_clk: + for (; i > 0; i--) + clk_disable_unprepare(this->resources.clock[i - 1]); + return ret; +} + +int gpmi_enable_clk(struct gpmi_nand_data *this) +{ + return __gpmi_enable_clk(this, true); +} + +int gpmi_disable_clk(struct gpmi_nand_data *this) +{ + return __gpmi_enable_clk(this, false); +} + +int gpmi_init(struct gpmi_nand_data *this) +{ + struct resources *r = &this->resources; + int ret; + + ret = gpmi_enable_clk(this); + if (ret) + return ret; + ret = gpmi_reset_block(r->gpmi_regs, false); + if (ret) + goto err_out; + + /* + * Reset BCH here, too. We got failures otherwise :( + * See later BCH reset for explanation of MX23 handling + */ + ret = gpmi_reset_block(r->bch_regs, GPMI_IS_MX23(this)); + if (ret) + goto err_out; + + /* Choose NAND mode. */ + writel(BM_GPMI_CTRL1_GPMI_MODE, r->gpmi_regs + HW_GPMI_CTRL1_CLR); + + /* Set the IRQ polarity. */ + writel(BM_GPMI_CTRL1_ATA_IRQRDY_POLARITY, + r->gpmi_regs + HW_GPMI_CTRL1_SET); + + /* Disable Write-Protection. */ + writel(BM_GPMI_CTRL1_DEV_RESET, r->gpmi_regs + HW_GPMI_CTRL1_SET); + + /* Select BCH ECC. */ + writel(BM_GPMI_CTRL1_BCH_MODE, r->gpmi_regs + HW_GPMI_CTRL1_SET); + + /* + * Decouple the chip select from dma channel. We use dma0 for all + * the chips. + */ + writel(BM_GPMI_CTRL1_DECOUPLE_CS, r->gpmi_regs + HW_GPMI_CTRL1_SET); + + gpmi_disable_clk(this); + return 0; +err_out: + gpmi_disable_clk(this); + return ret; +} + +/* This function is very useful. It is called only when the bug occur. */ +void gpmi_dump_info(struct gpmi_nand_data *this) +{ + struct resources *r = &this->resources; + struct bch_geometry *geo = &this->bch_geometry; + u32 reg; + int i; + + dev_err(this->dev, "Show GPMI registers :\n"); + for (i = 0; i <= HW_GPMI_DEBUG / 0x10 + 1; i++) { + reg = readl(r->gpmi_regs + i * 0x10); + dev_err(this->dev, "offset 0x%.3x : 0x%.8x\n", i * 0x10, reg); + } + + /* start to print out the BCH info */ + dev_err(this->dev, "Show BCH registers :\n"); + for (i = 0; i <= HW_BCH_VERSION / 0x10 + 1; i++) { + reg = readl(r->bch_regs + i * 0x10); + dev_err(this->dev, "offset 0x%.3x : 0x%.8x\n", i * 0x10, reg); + } + dev_err(this->dev, "BCH Geometry :\n" + "GF length : %u\n" + "ECC Strength : %u\n" + "Page Size in Bytes : %u\n" + "Metadata Size in Bytes : %u\n" + "ECC Chunk Size in Bytes: %u\n" + "ECC Chunk Count : %u\n" + "Payload Size in Bytes : %u\n" + "Auxiliary Size in Bytes: %u\n" + "Auxiliary Status Offset: %u\n" + "Block Mark Byte Offset : %u\n" + "Block Mark Bit Offset : %u\n", + geo->gf_len, + geo->ecc_strength, + geo->page_size, + geo->metadata_size, + geo->ecc_chunk_size, + geo->ecc_chunk_count, + geo->payload_size, + geo->auxiliary_size, + geo->auxiliary_status_offset, + geo->block_mark_byte_offset, + geo->block_mark_bit_offset); +} + +/* Configures the geometry for BCH. */ +int bch_set_geometry(struct gpmi_nand_data *this) +{ + struct resources *r = &this->resources; + struct bch_geometry *bch_geo = &this->bch_geometry; + unsigned int block_count; + unsigned int block_size; + unsigned int metadata_size; + unsigned int ecc_strength; + unsigned int page_size; + unsigned int gf_len; + int ret; + + if (common_nfc_set_geometry(this)) + return !0; + + block_count = bch_geo->ecc_chunk_count - 1; + block_size = bch_geo->ecc_chunk_size; + metadata_size = bch_geo->metadata_size; + ecc_strength = bch_geo->ecc_strength >> 1; + page_size = bch_geo->page_size; + gf_len = bch_geo->gf_len; + + ret = gpmi_enable_clk(this); + if (ret) + return ret; + + /* + * Due to erratum #2847 of the MX23, the BCH cannot be soft reset on this + * chip, otherwise it will lock up. So we skip resetting BCH on the MX23. + * On the other hand, the MX28 needs the reset, because one case has been + * seen where the BCH produced ECC errors constantly after 10000 + * consecutive reboots. The latter case has not been seen on the MX23 + * yet, still we don't know if it could happen there as well. + */ + ret = gpmi_reset_block(r->bch_regs, GPMI_IS_MX23(this)); + if (ret) + goto err_out; + + /* Configure layout 0. */ + writel(BF_BCH_FLASH0LAYOUT0_NBLOCKS(block_count) + | BF_BCH_FLASH0LAYOUT0_META_SIZE(metadata_size) + | BF_BCH_FLASH0LAYOUT0_ECC0(ecc_strength, this) + | BF_BCH_FLASH0LAYOUT0_GF(gf_len, this) + | BF_BCH_FLASH0LAYOUT0_DATA0_SIZE(block_size, this), + r->bch_regs + HW_BCH_FLASH0LAYOUT0); + + writel(BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(page_size) + | BF_BCH_FLASH0LAYOUT1_ECCN(ecc_strength, this) + | BF_BCH_FLASH0LAYOUT1_GF(gf_len, this) + | BF_BCH_FLASH0LAYOUT1_DATAN_SIZE(block_size, this), + r->bch_regs + HW_BCH_FLASH0LAYOUT1); + + /* Set *all* chip selects to use layout 0. */ + writel(0, r->bch_regs + HW_BCH_LAYOUTSELECT); + + /* Enable interrupts. */ + writel(BM_BCH_CTRL_COMPLETE_IRQ_EN, + r->bch_regs + HW_BCH_CTRL_SET); + + gpmi_disable_clk(this); + return 0; +err_out: + gpmi_disable_clk(this); + return ret; +} + +/* + * <1> Firstly, we should know what's the GPMI-clock means. + * The GPMI-clock is the internal clock in the gpmi nand controller. + * If you set 100MHz to gpmi nand controller, the GPMI-clock's period + * is 10ns. Mark the GPMI-clock's period as GPMI-clock-period. + * + * <2> Secondly, we should know what's the frequency on the nand chip pins. + * The frequency on the nand chip pins is derived from the GPMI-clock. + * We can get it from the following equation: + * + * F = G / (DS + DH) + * + * F : the frequency on the nand chip pins. + * G : the GPMI clock, such as 100MHz. + * DS : GPMI_HW_GPMI_TIMING0:DATA_SETUP + * DH : GPMI_HW_GPMI_TIMING0:DATA_HOLD + * + * <3> Thirdly, when the frequency on the nand chip pins is above 33MHz, + * the nand EDO(extended Data Out) timing could be applied. + * The GPMI implements a feedback read strobe to sample the read data. + * The feedback read strobe can be delayed to support the nand EDO timing + * where the read strobe may deasserts before the read data is valid, and + * read data is valid for some time after read strobe. + * + * The following figure illustrates some aspects of a NAND Flash read: + * + * |<---tREA---->| + * | | + * | | | + * |<--tRP-->| | + * | | | + * __ ___|__________________________________ + * RDN \________/ | + * | + * /---------\ + * Read Data --------------< >--------- + * \---------/ + * | | + * |<-D->| + * FeedbackRDN ________ ____________ + * \___________/ + * + * D stands for delay, set in the HW_GPMI_CTRL1:RDN_DELAY. + * + * + * <4> Now, we begin to describe how to compute the right RDN_DELAY. + * + * 4.1) From the aspect of the nand chip pins: + * Delay = (tREA + C - tRP) {1} + * + * tREA : the maximum read access time. + * C : a constant to adjust the delay. default is 4000ps. + * tRP : the read pulse width, which is exactly: + * tRP = (GPMI-clock-period) * DATA_SETUP + * + * 4.2) From the aspect of the GPMI nand controller: + * Delay = RDN_DELAY * 0.125 * RP {2} + * + * RP : the DLL reference period. + * if (GPMI-clock-period > DLL_THRETHOLD) + * RP = GPMI-clock-period / 2; + * else + * RP = GPMI-clock-period; + * + * Set the HW_GPMI_CTRL1:HALF_PERIOD if GPMI-clock-period + * is greater DLL_THRETHOLD. In other SOCs, the DLL_THRETHOLD + * is 16000ps, but in mx6q, we use 12000ps. + * + * 4.3) since {1} equals {2}, we get: + * + * (tREA + 4000 - tRP) * 8 + * RDN_DELAY = ----------------------- {3} + * RP + */ +static void gpmi_nfc_compute_timings(struct gpmi_nand_data *this, + const struct nand_sdr_timings *sdr) +{ + struct gpmi_nfc_hardware_timing *hw = &this->hw; + unsigned int dll_threshold_ps = this->devdata->max_chain_delay; + unsigned int period_ps, reference_period_ps; + unsigned int data_setup_cycles, data_hold_cycles, addr_setup_cycles; + unsigned int tRP_ps; + bool use_half_period; + int sample_delay_ps, sample_delay_factor; + u16 busy_timeout_cycles; + u8 wrn_dly_sel; + + if (sdr->tRC_min >= 30000) { + /* ONFI non-EDO modes [0-3] */ + hw->clk_rate = 22000000; + wrn_dly_sel = BV_GPMI_CTRL1_WRN_DLY_SEL_4_TO_8NS; + } else if (sdr->tRC_min >= 25000) { + /* ONFI EDO mode 4 */ + hw->clk_rate = 80000000; + wrn_dly_sel = BV_GPMI_CTRL1_WRN_DLY_SEL_NO_DELAY; + } else { + /* ONFI EDO mode 5 */ + hw->clk_rate = 100000000; + wrn_dly_sel = BV_GPMI_CTRL1_WRN_DLY_SEL_NO_DELAY; + } + + /* SDR core timings are given in picoseconds */ + period_ps = div_u64((u64)NSEC_PER_SEC * 1000, hw->clk_rate); + + addr_setup_cycles = TO_CYCLES(sdr->tALS_min, period_ps); + data_setup_cycles = TO_CYCLES(sdr->tDS_min, period_ps); + data_hold_cycles = TO_CYCLES(sdr->tDH_min, period_ps); + busy_timeout_cycles = TO_CYCLES(sdr->tWB_max + sdr->tR_max, period_ps); + + hw->timing0 = BF_GPMI_TIMING0_ADDRESS_SETUP(addr_setup_cycles) | + BF_GPMI_TIMING0_DATA_HOLD(data_hold_cycles) | + BF_GPMI_TIMING0_DATA_SETUP(data_setup_cycles); + hw->timing1 = BF_GPMI_TIMING1_BUSY_TIMEOUT(busy_timeout_cycles * 4096); + + /* + * Derive NFC ideal delay from {3}: + * + * (tREA + 4000 - tRP) * 8 + * RDN_DELAY = ----------------------- + * RP + */ + if (period_ps > dll_threshold_ps) { + use_half_period = true; + reference_period_ps = period_ps / 2; + } else { + use_half_period = false; + reference_period_ps = period_ps; + } + + tRP_ps = data_setup_cycles * period_ps; + sample_delay_ps = (sdr->tREA_max + 4000 - tRP_ps) * 8; + if (sample_delay_ps > 0) + sample_delay_factor = sample_delay_ps / reference_period_ps; + else + sample_delay_factor = 0; + + hw->ctrl1n = BF_GPMI_CTRL1_WRN_DLY_SEL(wrn_dly_sel); + if (sample_delay_factor) + hw->ctrl1n |= BF_GPMI_CTRL1_RDN_DELAY(sample_delay_factor) | + BM_GPMI_CTRL1_DLL_ENABLE | + (use_half_period ? BM_GPMI_CTRL1_HALF_PERIOD : 0); +} + +void gpmi_nfc_apply_timings(struct gpmi_nand_data *this) +{ + struct gpmi_nfc_hardware_timing *hw = &this->hw; + struct resources *r = &this->resources; + void __iomem *gpmi_regs = r->gpmi_regs; + unsigned int dll_wait_time_us; + + clk_set_rate(r->clock[0], hw->clk_rate); + + writel(hw->timing0, gpmi_regs + HW_GPMI_TIMING0); + writel(hw->timing1, gpmi_regs + HW_GPMI_TIMING1); + + /* + * Clear several CTRL1 fields, DLL must be disabled when setting + * RDN_DELAY or HALF_PERIOD. + */ + writel(BM_GPMI_CTRL1_CLEAR_MASK, gpmi_regs + HW_GPMI_CTRL1_CLR); + writel(hw->ctrl1n, gpmi_regs + HW_GPMI_CTRL1_SET); + + /* Wait 64 clock cycles before using the GPMI after enabling the DLL */ + dll_wait_time_us = USEC_PER_SEC / hw->clk_rate * 64; + if (!dll_wait_time_us) + dll_wait_time_us = 1; + + /* Wait for the DLL to settle. */ + udelay(dll_wait_time_us); +} + +int gpmi_setup_data_interface(struct mtd_info *mtd, int chipnr, + const struct nand_data_interface *conf) +{ + struct nand_chip *chip = mtd_to_nand(mtd); + struct gpmi_nand_data *this = nand_get_controller_data(chip); + const struct nand_sdr_timings *sdr; + + /* Retrieve required NAND timings */ + sdr = nand_get_sdr_timings(conf); + if (IS_ERR(sdr)) + return PTR_ERR(sdr); + + /* Only MX6 GPMI controller can reach EDO timings */ + if (sdr->tRC_min <= 25000 && !GPMI_IS_MX6(this)) + return -ENOTSUPP; + + /* Stop here if this call was just a check */ + if (chipnr < 0) + return 0; + + /* Do the actual derivation of the controller timings */ + gpmi_nfc_compute_timings(this, sdr); + + this->hw.must_apply_timings = true; + + return 0; +} + +/* Clears a BCH interrupt. */ +void gpmi_clear_bch(struct gpmi_nand_data *this) +{ + struct resources *r = &this->resources; + writel(BM_BCH_CTRL_COMPLETE_IRQ, r->bch_regs + HW_BCH_CTRL_CLR); +} + +/* Returns the Ready/Busy status of the given chip. */ +int gpmi_is_ready(struct gpmi_nand_data *this, unsigned chip) +{ + struct resources *r = &this->resources; + uint32_t mask = 0; + uint32_t reg = 0; + + if (GPMI_IS_MX23(this)) { + mask = MX23_BM_GPMI_DEBUG_READY0 << chip; + reg = readl(r->gpmi_regs + HW_GPMI_DEBUG); + } else if (GPMI_IS_MX28(this) || GPMI_IS_MX6(this)) { + /* + * In the imx6, all the ready/busy pins are bound + * together. So we only need to check chip 0. + */ + if (GPMI_IS_MX6(this)) + chip = 0; + + /* MX28 shares the same R/B register as MX6Q. */ + mask = MX28_BF_GPMI_STAT_READY_BUSY(1 << chip); + reg = readl(r->gpmi_regs + HW_GPMI_STAT); + } else + dev_err(this->dev, "unknown arch.\n"); + return reg & mask; +} + +static inline void set_dma_type(struct gpmi_nand_data *this, + enum dma_ops_type type) +{ + this->last_dma_type = this->dma_type; + this->dma_type = type; +} + +int gpmi_send_command(struct gpmi_nand_data *this) +{ + struct dma_chan *channel = get_dma_chan(this); + struct dma_async_tx_descriptor *desc; + struct scatterlist *sgl; + int chip = this->current_chip; + u32 pio[3]; + + /* [1] send out the PIO words */ + pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(BV_GPMI_CTRL0_COMMAND_MODE__WRITE) + | BM_GPMI_CTRL0_WORD_LENGTH + | BF_GPMI_CTRL0_CS(chip, this) + | BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this) + | BF_GPMI_CTRL0_ADDRESS(BV_GPMI_CTRL0_ADDRESS__NAND_CLE) + | BM_GPMI_CTRL0_ADDRESS_INCREMENT + | BF_GPMI_CTRL0_XFER_COUNT(this->command_length); + pio[1] = pio[2] = 0; + desc = dmaengine_prep_slave_sg(channel, + (struct scatterlist *)pio, + ARRAY_SIZE(pio), DMA_TRANS_NONE, 0); + if (!desc) + return -EINVAL; + + /* [2] send out the COMMAND + ADDRESS string stored in @buffer */ + sgl = &this->cmd_sgl; + + sg_init_one(sgl, this->cmd_buffer, this->command_length); + dma_map_sg(this->dev, sgl, 1, DMA_TO_DEVICE); + desc = dmaengine_prep_slave_sg(channel, + sgl, 1, DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) + return -EINVAL; + + /* [3] submit the DMA */ + set_dma_type(this, DMA_FOR_COMMAND); + return start_dma_without_bch_irq(this, desc); +} + +int gpmi_send_data(struct gpmi_nand_data *this) +{ + struct dma_async_tx_descriptor *desc; + struct dma_chan *channel = get_dma_chan(this); + int chip = this->current_chip; + uint32_t command_mode; + uint32_t address; + u32 pio[2]; + + /* [1] PIO */ + command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WRITE; + address = BV_GPMI_CTRL0_ADDRESS__NAND_DATA; + + pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(command_mode) + | BM_GPMI_CTRL0_WORD_LENGTH + | BF_GPMI_CTRL0_CS(chip, this) + | BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this) + | BF_GPMI_CTRL0_ADDRESS(address) + | BF_GPMI_CTRL0_XFER_COUNT(this->upper_len); + pio[1] = 0; + desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)pio, + ARRAY_SIZE(pio), DMA_TRANS_NONE, 0); + if (!desc) + return -EINVAL; + + /* [2] send DMA request */ + prepare_data_dma(this, DMA_TO_DEVICE); + desc = dmaengine_prep_slave_sg(channel, &this->data_sgl, + 1, DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) + return -EINVAL; + + /* [3] submit the DMA */ + set_dma_type(this, DMA_FOR_WRITE_DATA); + return start_dma_without_bch_irq(this, desc); +} + +int gpmi_read_data(struct gpmi_nand_data *this) +{ + struct dma_async_tx_descriptor *desc; + struct dma_chan *channel = get_dma_chan(this); + int chip = this->current_chip; + u32 pio[2]; + + /* [1] : send PIO */ + pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(BV_GPMI_CTRL0_COMMAND_MODE__READ) + | BM_GPMI_CTRL0_WORD_LENGTH + | BF_GPMI_CTRL0_CS(chip, this) + | BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this) + | BF_GPMI_CTRL0_ADDRESS(BV_GPMI_CTRL0_ADDRESS__NAND_DATA) + | BF_GPMI_CTRL0_XFER_COUNT(this->upper_len); + pio[1] = 0; + desc = dmaengine_prep_slave_sg(channel, + (struct scatterlist *)pio, + ARRAY_SIZE(pio), DMA_TRANS_NONE, 0); + if (!desc) + return -EINVAL; + + /* [2] : send DMA request */ + prepare_data_dma(this, DMA_FROM_DEVICE); + desc = dmaengine_prep_slave_sg(channel, &this->data_sgl, + 1, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) + return -EINVAL; + + /* [3] : submit the DMA */ + set_dma_type(this, DMA_FOR_READ_DATA); + return start_dma_without_bch_irq(this, desc); +} + +int gpmi_send_page(struct gpmi_nand_data *this, + dma_addr_t payload, dma_addr_t auxiliary) +{ + struct bch_geometry *geo = &this->bch_geometry; + uint32_t command_mode; + uint32_t address; + uint32_t ecc_command; + uint32_t buffer_mask; + struct dma_async_tx_descriptor *desc; + struct dma_chan *channel = get_dma_chan(this); + int chip = this->current_chip; + u32 pio[6]; + + /* A DMA descriptor that does an ECC page read. */ + command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WRITE; + address = BV_GPMI_CTRL0_ADDRESS__NAND_DATA; + ecc_command = BV_GPMI_ECCCTRL_ECC_CMD__BCH_ENCODE; + buffer_mask = BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_PAGE | + BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_AUXONLY; + + pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(command_mode) + | BM_GPMI_CTRL0_WORD_LENGTH + | BF_GPMI_CTRL0_CS(chip, this) + | BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this) + | BF_GPMI_CTRL0_ADDRESS(address) + | BF_GPMI_CTRL0_XFER_COUNT(0); + pio[1] = 0; + pio[2] = BM_GPMI_ECCCTRL_ENABLE_ECC + | BF_GPMI_ECCCTRL_ECC_CMD(ecc_command) + | BF_GPMI_ECCCTRL_BUFFER_MASK(buffer_mask); + pio[3] = geo->page_size; + pio[4] = payload; + pio[5] = auxiliary; + + desc = dmaengine_prep_slave_sg(channel, + (struct scatterlist *)pio, + ARRAY_SIZE(pio), DMA_TRANS_NONE, + DMA_CTRL_ACK); + if (!desc) + return -EINVAL; + + set_dma_type(this, DMA_FOR_WRITE_ECC_PAGE); + return start_dma_with_bch_irq(this, desc); +} + +int gpmi_read_page(struct gpmi_nand_data *this, + dma_addr_t payload, dma_addr_t auxiliary) +{ + struct bch_geometry *geo = &this->bch_geometry; + uint32_t command_mode; + uint32_t address; + uint32_t ecc_command; + uint32_t buffer_mask; + struct dma_async_tx_descriptor *desc; + struct dma_chan *channel = get_dma_chan(this); + int chip = this->current_chip; + u32 pio[6]; + + /* [1] Wait for the chip to report ready. */ + command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WAIT_FOR_READY; + address = BV_GPMI_CTRL0_ADDRESS__NAND_DATA; + + pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(command_mode) + | BM_GPMI_CTRL0_WORD_LENGTH + | BF_GPMI_CTRL0_CS(chip, this) + | BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this) + | BF_GPMI_CTRL0_ADDRESS(address) + | BF_GPMI_CTRL0_XFER_COUNT(0); + pio[1] = 0; + desc = dmaengine_prep_slave_sg(channel, + (struct scatterlist *)pio, 2, + DMA_TRANS_NONE, 0); + if (!desc) + return -EINVAL; + + /* [2] Enable the BCH block and read. */ + command_mode = BV_GPMI_CTRL0_COMMAND_MODE__READ; + address = BV_GPMI_CTRL0_ADDRESS__NAND_DATA; + ecc_command = BV_GPMI_ECCCTRL_ECC_CMD__BCH_DECODE; + buffer_mask = BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_PAGE + | BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_AUXONLY; + + pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(command_mode) + | BM_GPMI_CTRL0_WORD_LENGTH + | BF_GPMI_CTRL0_CS(chip, this) + | BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this) + | BF_GPMI_CTRL0_ADDRESS(address) + | BF_GPMI_CTRL0_XFER_COUNT(geo->page_size); + + pio[1] = 0; + pio[2] = BM_GPMI_ECCCTRL_ENABLE_ECC + | BF_GPMI_ECCCTRL_ECC_CMD(ecc_command) + | BF_GPMI_ECCCTRL_BUFFER_MASK(buffer_mask); + pio[3] = geo->page_size; + pio[4] = payload; + pio[5] = auxiliary; + desc = dmaengine_prep_slave_sg(channel, + (struct scatterlist *)pio, + ARRAY_SIZE(pio), DMA_TRANS_NONE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) + return -EINVAL; + + /* [3] Disable the BCH block */ + command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WAIT_FOR_READY; + address = BV_GPMI_CTRL0_ADDRESS__NAND_DATA; + + pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(command_mode) + | BM_GPMI_CTRL0_WORD_LENGTH + | BF_GPMI_CTRL0_CS(chip, this) + | BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this) + | BF_GPMI_CTRL0_ADDRESS(address) + | BF_GPMI_CTRL0_XFER_COUNT(geo->page_size); + pio[1] = 0; + pio[2] = 0; /* clear GPMI_HW_GPMI_ECCCTRL, disable the BCH. */ + desc = dmaengine_prep_slave_sg(channel, + (struct scatterlist *)pio, 3, + DMA_TRANS_NONE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) + return -EINVAL; + + /* [4] submit the DMA */ + set_dma_type(this, DMA_FOR_READ_ECC_PAGE); + return start_dma_with_bch_irq(this, desc); +} + +/** + * gpmi_copy_bits - copy bits from one memory region to another + * @dst: destination buffer + * @dst_bit_off: bit offset we're starting to write at + * @src: source buffer + * @src_bit_off: bit offset we're starting to read from + * @nbits: number of bits to copy + * + * This functions copies bits from one memory region to another, and is used by + * the GPMI driver to copy ECC sections which are not guaranteed to be byte + * aligned. + * + * src and dst should not overlap. + * + */ +void gpmi_copy_bits(u8 *dst, size_t dst_bit_off, + const u8 *src, size_t src_bit_off, + size_t nbits) +{ + size_t i; + size_t nbytes; + u32 src_buffer = 0; + size_t bits_in_src_buffer = 0; + + if (!nbits) + return; + + /* + * Move src and dst pointers to the closest byte pointer and store bit + * offsets within a byte. + */ + src += src_bit_off / 8; + src_bit_off %= 8; + + dst += dst_bit_off / 8; + dst_bit_off %= 8; + + /* + * Initialize the src_buffer value with bits available in the first + * byte of data so that we end up with a byte aligned src pointer. + */ + if (src_bit_off) { + src_buffer = src[0] >> src_bit_off; + if (nbits >= (8 - src_bit_off)) { + bits_in_src_buffer += 8 - src_bit_off; + } else { + src_buffer &= GENMASK(nbits - 1, 0); + bits_in_src_buffer += nbits; + } + nbits -= bits_in_src_buffer; + src++; + } + + /* Calculate the number of bytes that can be copied from src to dst. */ + nbytes = nbits / 8; + + /* Try to align dst to a byte boundary. */ + if (dst_bit_off) { + if (bits_in_src_buffer < (8 - dst_bit_off) && nbytes) { + src_buffer |= src[0] << bits_in_src_buffer; + bits_in_src_buffer += 8; + src++; + nbytes--; + } + + if (bits_in_src_buffer >= (8 - dst_bit_off)) { + dst[0] &= GENMASK(dst_bit_off - 1, 0); + dst[0] |= src_buffer << dst_bit_off; + src_buffer >>= (8 - dst_bit_off); + bits_in_src_buffer -= (8 - dst_bit_off); + dst_bit_off = 0; + dst++; + if (bits_in_src_buffer > 7) { + bits_in_src_buffer -= 8; + dst[0] = src_buffer; + dst++; + src_buffer >>= 8; + } + } + } + + if (!bits_in_src_buffer && !dst_bit_off) { + /* + * Both src and dst pointers are byte aligned, thus we can + * just use the optimized memcpy function. + */ + if (nbytes) + memcpy(dst, src, nbytes); + } else { + /* + * src buffer is not byte aligned, hence we have to copy each + * src byte to the src_buffer variable before extracting a byte + * to store in dst. + */ + for (i = 0; i < nbytes; i++) { + src_buffer |= src[i] << bits_in_src_buffer; + dst[i] = src_buffer; + src_buffer >>= 8; + } + } + /* Update dst and src pointers */ + dst += nbytes; + src += nbytes; + + /* + * nbits is the number of remaining bits. It should not exceed 8 as + * we've already copied as much bytes as possible. + */ + nbits %= 8; + + /* + * If there's no more bits to copy to the destination and src buffer + * was already byte aligned, then we're done. + */ + if (!nbits && !bits_in_src_buffer) + return; + + /* Copy the remaining bits to src_buffer */ + if (nbits) + src_buffer |= (*src & GENMASK(nbits - 1, 0)) << + bits_in_src_buffer; + bits_in_src_buffer += nbits; + + /* + * In case there were not enough bits to get a byte aligned dst buffer + * prepare the src_buffer variable to match the dst organization (shift + * src_buffer by dst_bit_off and retrieve the least significant bits + * from dst). + */ + if (dst_bit_off) + src_buffer = (src_buffer << dst_bit_off) | + (*dst & GENMASK(dst_bit_off - 1, 0)); + bits_in_src_buffer += dst_bit_off; + + /* + * Keep most significant bits from dst if we end up with an unaligned + * number of bits. + */ + nbytes = bits_in_src_buffer / 8; + if (bits_in_src_buffer % 8) { + src_buffer |= (dst[nbytes] & + GENMASK(7, bits_in_src_buffer % 8)) << + (nbytes * 8); + nbytes++; + } + + /* Copy the remaining bytes to dst */ + for (i = 0; i < nbytes; i++) { + dst[i] = src_buffer; + src_buffer >>= 8; + } +} |
