aubrey/kernel_samsung_a34x-permissive
1
0
Fork 0
Code Issues Pull requests Actions Packages Projects Releases Wiki Activity
kernel_samsung_a34x-permissive/drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c
Fede2782 6db4831e98
Import A346BXXU4BWK2 kernel source 
Android 14
2024-04-28 15:51:13 +02:00

938 lines
26 KiB
C
Raw Permalink Blame History

// SPDX-License-Identifier: GPL-2.0+
/*
* Freescale GPMI NAND Flash Driver
*
* Copyright (C) 2008-2011 Freescale Semiconductor, Inc.
* Copyright (C) 2008 Embedded Alley Solutions, Inc.
*/
#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 and MX28 handling
*/
ret = gpmi_reset_block(r->bch_regs,
GPMI_IS_MX23(this) || GPMI_IS_MX28(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;
ret = common_nfc_set_geometry(this);
if (ret)
return ret;
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.
* and MX28.
*/
ret = gpmi_reset_block(r->bch_regs,
GPMI_IS_MX23(this) || GPMI_IS_MX28(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;
}
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;
int ret;
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 */
ret = start_dma_without_bch_irq(this, desc);
dma_unmap_sg(this->dev, sgl, 1, DMA_TO_DEVICE);
return ret;
}
int gpmi_send_data(struct gpmi_nand_data *this, const void *buf, int len)
{
struct dma_async_tx_descriptor *desc;
struct dma_chan *channel = get_dma_chan(this);
int chip = this->current_chip;
int ret;
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(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, buf, len, 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 */
ret = start_dma_without_bch_irq(this, desc);
dma_unmap_sg(this->dev, &this->data_sgl, 1, DMA_TO_DEVICE);
return ret;
}
int gpmi_read_data(struct gpmi_nand_data *this, void *buf, int len)
{
struct dma_async_tx_descriptor *desc;
struct dma_chan *channel = get_dma_chan(this);
int chip = this->current_chip;
int ret;
u32 pio[2];
bool direct;
/* [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(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 */
direct = prepare_data_dma(this, buf, len, 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 */
ret = start_dma_without_bch_irq(this, desc);
dma_unmap_sg(this->dev, &this->data_sgl, 1, DMA_FROM_DEVICE);
if (!direct)
memcpy(buf, this->data_buffer_dma, len);
return ret;
}
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;
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 */
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;
}
}
Reference in a new issue View git blame Copy permalink