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linux/drivers/mtd/nand/raw/tmio_nand.c
Miquel Raynal 048fbdd599 Revert "mtd: rawnand: tmio: Fix external use of SW Hamming ECC helper" 
This reverts commit 6a4c5ada577467a5f79e06f2c5e69c09983c22fb.

Before the introduction of the ECC framework infrastructure, many
drivers used the ->calculate/correct() Hamming helpers directly. The
point of this framework was to avoid this kind of hackish calls and use a
proper and generic API but it is true that in certain cases, drivers
still need to use these helpers in order to do ECC computations on
behalf of their limited hardware.

Right after the introduction of the ECC engine core introduction, it was
spotted that it was not possible to use the shiny rawnand software ECC
helpers so easily because an ECC engine object should have been
allocated and initialized first. While this works well in most cases,
for these drivers just leveraging the power of a single helper in
conjunction with some pretty old and limited hardware, it did not fit.

The idea back then was to declare intermediate helpers which would make
use of the exported software ECC engine bare functions while keeping the
rawnand layer compatibility. As there was already functions with the
rawnand_sw_hamming_ prefix it was decided to declare new local helpers
for this purpose in each driver needing one.

Besides being far from optimal, this design choice was blamed by Linus
when he pulled the "fixes" pull request [1] so that is why now it is
time to clean this mess up.

The implementation of the rawnand_ecc_sw_* helpers has now been enhanced
to support both cases, when the ECC object is instantiated and when it is
not. This way, we can still use the existing and exported rawnand
helpers while avoiding the need for each driver to declare its own
helper, thus this fix from [2] can now be safely reverted.

[1] https://lore.kernel.org/lkml/CAHk-=wh_ZHF685Fni8V9is17mj=pFisUaZ_0=gq6nbK+ZcyQmg@mail.gmail.com/
[2] https://lore.kernel.org/linux-mtd/20210413161840.345208-1-miquel.raynal@bootlin.com

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210928221507.199198-5-miquel.raynal@bootlin.com
2021-10-15 12:21:03 +02:00

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/*
* Toshiba TMIO NAND flash controller driver
*
* Slightly murky pre-git history of the driver:
*
* Copyright (c) Ian Molton 2004, 2005, 2008
* Original work, independent of sharps code. Included hardware ECC support.
* Hard ECC did not work for writes in the early revisions.
* Copyright (c) Dirk Opfer 2005.
* Modifications developed from sharps code but
* NOT containing any, ported onto Ians base.
* Copyright (c) Chris Humbert 2005
* Copyright (c) Dmitry Baryshkov 2008
* Minor fixes
*
* Parts copyright Sebastian Carlier
*
* This file is licensed under
* the terms of the GNU General Public License version 2. This program
* is licensed "as is" without any warranty of any kind, whether express
* or implied.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mfd/core.h>
#include <linux/mfd/tmio.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/rawnand.h>
#include <linux/mtd/partitions.h>
#include <linux/slab.h>
/*--------------------------------------------------------------------------*/
/*
* NAND Flash Host Controller Configuration Register
*/
#define CCR_COMMAND 0x04 /* w Command */
#define CCR_BASE 0x10 /* l NAND Flash Control Reg Base Addr */
#define CCR_INTP 0x3d /* b Interrupt Pin */
#define CCR_INTE 0x48 /* b Interrupt Enable */
#define CCR_EC 0x4a /* b Event Control */
#define CCR_ICC 0x4c /* b Internal Clock Control */
#define CCR_ECCC 0x5b /* b ECC Control */
#define CCR_NFTC 0x60 /* b NAND Flash Transaction Control */
#define CCR_NFM 0x61 /* b NAND Flash Monitor */
#define CCR_NFPSC 0x62 /* b NAND Flash Power Supply Control */
#define CCR_NFDC 0x63 /* b NAND Flash Detect Control */
/*
* NAND Flash Control Register
*/
#define FCR_DATA 0x00 /* bwl Data Register */
#define FCR_MODE 0x04 /* b Mode Register */
#define FCR_STATUS 0x05 /* b Status Register */
#define FCR_ISR 0x06 /* b Interrupt Status Register */
#define FCR_IMR 0x07 /* b Interrupt Mask Register */
/* FCR_MODE Register Command List */
#define FCR_MODE_DATA 0x94 /* Data Data_Mode */
#define FCR_MODE_COMMAND 0x95 /* Data Command_Mode */
#define FCR_MODE_ADDRESS 0x96 /* Data Address_Mode */
#define FCR_MODE_HWECC_CALC 0xB4 /* HW-ECC Data */
#define FCR_MODE_HWECC_RESULT 0xD4 /* HW-ECC Calc result Read_Mode */
#define FCR_MODE_HWECC_RESET 0xF4 /* HW-ECC Reset */
#define FCR_MODE_POWER_ON 0x0C /* Power Supply ON to SSFDC card */
#define FCR_MODE_POWER_OFF 0x08 /* Power Supply OFF to SSFDC card */
#define FCR_MODE_LED_OFF 0x00 /* LED OFF */
#define FCR_MODE_LED_ON 0x04 /* LED ON */
#define FCR_MODE_EJECT_ON 0x68 /* Ejection events active */
#define FCR_MODE_EJECT_OFF 0x08 /* Ejection events ignored */
#define FCR_MODE_LOCK 0x6C /* Lock_Mode. Eject Switch Invalid */
#define FCR_MODE_UNLOCK 0x0C /* UnLock_Mode. Eject Switch is valid */
#define FCR_MODE_CONTROLLER_ID 0x40 /* Controller ID Read */
#define FCR_MODE_STANDBY 0x00 /* SSFDC card Changes Standby State */
#define FCR_MODE_WE 0x80
#define FCR_MODE_ECC1 0x40
#define FCR_MODE_ECC0 0x20
#define FCR_MODE_CE 0x10
#define FCR_MODE_PCNT1 0x08
#define FCR_MODE_PCNT0 0x04
#define FCR_MODE_ALE 0x02
#define FCR_MODE_CLE 0x01
#define FCR_STATUS_BUSY 0x80
/*--------------------------------------------------------------------------*/
struct tmio_nand {
struct nand_controller controller;
struct nand_chip chip;
struct completion comp;
struct platform_device *dev;
void __iomem *ccr;
void __iomem *fcr;
unsigned long fcr_base;
unsigned int irq;
/* for tmio_nand_read_byte */
u8 read;
unsigned read_good:1;
};
static inline struct tmio_nand *mtd_to_tmio(struct mtd_info *mtd)
{
return container_of(mtd_to_nand(mtd), struct tmio_nand, chip);
}
/*--------------------------------------------------------------------------*/
static void tmio_nand_hwcontrol(struct nand_chip *chip, int cmd,
unsigned int ctrl)
{
struct tmio_nand *tmio = mtd_to_tmio(nand_to_mtd(chip));
if (ctrl & NAND_CTRL_CHANGE) {
u8 mode;
if (ctrl & NAND_NCE) {
mode = FCR_MODE_DATA;
if (ctrl & NAND_CLE)
mode |= FCR_MODE_CLE;
else
mode &= ~FCR_MODE_CLE;
if (ctrl & NAND_ALE)
mode |= FCR_MODE_ALE;
else
mode &= ~FCR_MODE_ALE;
} else {
mode = FCR_MODE_STANDBY;
}
tmio_iowrite8(mode, tmio->fcr + FCR_MODE);
tmio->read_good = 0;
}
if (cmd != NAND_CMD_NONE)
tmio_iowrite8(cmd, chip->legacy.IO_ADDR_W);
}
static int tmio_nand_dev_ready(struct nand_chip *chip)
{
struct tmio_nand *tmio = mtd_to_tmio(nand_to_mtd(chip));
return !(tmio_ioread8(tmio->fcr + FCR_STATUS) & FCR_STATUS_BUSY);
}
static irqreturn_t tmio_irq(int irq, void *__tmio)
{
struct tmio_nand *tmio = __tmio;
/* disable RDYREQ interrupt */
tmio_iowrite8(0x00, tmio->fcr + FCR_IMR);
complete(&tmio->comp);
return IRQ_HANDLED;
}
/*
*The TMIO core has a RDYREQ interrupt on the posedge of #SMRB.
*This interrupt is normally disabled, but for long operations like
*erase and write, we enable it to wake us up. The irq handler
*disables the interrupt.
*/
static int tmio_nand_wait(struct nand_chip *nand_chip)
{
struct tmio_nand *tmio = mtd_to_tmio(nand_to_mtd(nand_chip));
long timeout;
u8 status;
/* enable RDYREQ interrupt */
tmio_iowrite8(0x0f, tmio->fcr + FCR_ISR);
reinit_completion(&tmio->comp);
tmio_iowrite8(0x81, tmio->fcr + FCR_IMR);
timeout = 400;
timeout = wait_for_completion_timeout(&tmio->comp,
msecs_to_jiffies(timeout));
if (unlikely(!tmio_nand_dev_ready(nand_chip))) {
tmio_iowrite8(0x00, tmio->fcr + FCR_IMR);
dev_warn(&tmio->dev->dev, "still busy after 400 ms\n");
} else if (unlikely(!timeout)) {
tmio_iowrite8(0x00, tmio->fcr + FCR_IMR);
dev_warn(&tmio->dev->dev, "timeout waiting for interrupt\n");
}
nand_status_op(nand_chip, &status);
return status;
}
/*
*The TMIO controller combines two 8-bit data bytes into one 16-bit
*word. This function separates them so nand_base.c works as expected,
*especially its NAND_CMD_READID routines.
*
*To prevent stale data from being read, tmio_nand_hwcontrol() clears
*tmio->read_good.
*/
static u_char tmio_nand_read_byte(struct nand_chip *chip)
{
struct tmio_nand *tmio = mtd_to_tmio(nand_to_mtd(chip));
unsigned int data;
if (tmio->read_good--)
return tmio->read;
data = tmio_ioread16(tmio->fcr + FCR_DATA);
tmio->read = data >> 8;
return data;
}
/*
*The TMIO controller converts an 8-bit NAND interface to a 16-bit
*bus interface, so all data reads and writes must be 16-bit wide.
*Thus, we implement 16-bit versions of the read, write, and verify
*buffer functions.
*/
static void
tmio_nand_write_buf(struct nand_chip *chip, const u_char *buf, int len)
{
struct tmio_nand *tmio = mtd_to_tmio(nand_to_mtd(chip));
tmio_iowrite16_rep(tmio->fcr + FCR_DATA, buf, len >> 1);
}
static void tmio_nand_read_buf(struct nand_chip *chip, u_char *buf, int len)
{
struct tmio_nand *tmio = mtd_to_tmio(nand_to_mtd(chip));
tmio_ioread16_rep(tmio->fcr + FCR_DATA, buf, len >> 1);
}
static void tmio_nand_enable_hwecc(struct nand_chip *chip, int mode)
{
struct tmio_nand *tmio = mtd_to_tmio(nand_to_mtd(chip));
tmio_iowrite8(FCR_MODE_HWECC_RESET, tmio->fcr + FCR_MODE);
tmio_ioread8(tmio->fcr + FCR_DATA); /* dummy read */
tmio_iowrite8(FCR_MODE_HWECC_CALC, tmio->fcr + FCR_MODE);
}
static int tmio_nand_calculate_ecc(struct nand_chip *chip, const u_char *dat,
u_char *ecc_code)
{
struct tmio_nand *tmio = mtd_to_tmio(nand_to_mtd(chip));
unsigned int ecc;
tmio_iowrite8(FCR_MODE_HWECC_RESULT, tmio->fcr + FCR_MODE);
ecc = tmio_ioread16(tmio->fcr + FCR_DATA);
ecc_code[1] = ecc; /* 000-255 LP7-0 */
ecc_code[0] = ecc >> 8; /* 000-255 LP15-8 */
ecc = tmio_ioread16(tmio->fcr + FCR_DATA);
ecc_code[2] = ecc; /* 000-255 CP5-0,11b */
ecc_code[4] = ecc >> 8; /* 256-511 LP7-0 */
ecc = tmio_ioread16(tmio->fcr + FCR_DATA);
ecc_code[3] = ecc; /* 256-511 LP15-8 */
ecc_code[5] = ecc >> 8; /* 256-511 CP5-0,11b */
tmio_iowrite8(FCR_MODE_DATA, tmio->fcr + FCR_MODE);
return 0;
}
static int tmio_nand_correct_data(struct nand_chip *chip, unsigned char *buf,
unsigned char *read_ecc,
unsigned char *calc_ecc)
{
int r0, r1;
/* assume ecc.size = 512 and ecc.bytes = 6 */
r0 = rawnand_sw_hamming_correct(chip, buf, read_ecc, calc_ecc);
if (r0 < 0)
return r0;
r1 = rawnand_sw_hamming_correct(chip, buf + 256, read_ecc + 3,
calc_ecc + 3);
if (r1 < 0)
return r1;
return r0 + r1;
}
static int tmio_hw_init(struct platform_device *dev, struct tmio_nand *tmio)
{
const struct mfd_cell *cell = mfd_get_cell(dev);
int ret;
if (cell->enable) {
ret = cell->enable(dev);
if (ret)
return ret;
}
/* (4Ch) CLKRUN Enable 1st spcrunc */
tmio_iowrite8(0x81, tmio->ccr + CCR_ICC);
/* (10h)BaseAddress 0x1000 spba.spba2 */
tmio_iowrite16(tmio->fcr_base, tmio->ccr + CCR_BASE);
tmio_iowrite16(tmio->fcr_base >> 16, tmio->ccr + CCR_BASE + 2);
/* (04h)Command Register I/O spcmd */
tmio_iowrite8(0x02, tmio->ccr + CCR_COMMAND);
/* (62h) Power Supply Control ssmpwc */
/* HardPowerOFF - SuspendOFF - PowerSupplyWait_4MS */
tmio_iowrite8(0x02, tmio->ccr + CCR_NFPSC);
/* (63h) Detect Control ssmdtc */
tmio_iowrite8(0x02, tmio->ccr + CCR_NFDC);
/* Interrupt status register clear sintst */
tmio_iowrite8(0x0f, tmio->fcr + FCR_ISR);
/* After power supply, Media are reset smode */
tmio_iowrite8(FCR_MODE_POWER_ON, tmio->fcr + FCR_MODE);
tmio_iowrite8(FCR_MODE_COMMAND, tmio->fcr + FCR_MODE);
tmio_iowrite8(NAND_CMD_RESET, tmio->fcr + FCR_DATA);
/* Standby Mode smode */
tmio_iowrite8(FCR_MODE_STANDBY, tmio->fcr + FCR_MODE);
mdelay(5);
return 0;
}
static void tmio_hw_stop(struct platform_device *dev, struct tmio_nand *tmio)
{
const struct mfd_cell *cell = mfd_get_cell(dev);
tmio_iowrite8(FCR_MODE_POWER_OFF, tmio->fcr + FCR_MODE);
if (cell->disable)
cell->disable(dev);
}
static int tmio_attach_chip(struct nand_chip *chip)
{
if (chip->ecc.engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST)
return 0;
chip->ecc.size = 512;
chip->ecc.bytes = 6;
chip->ecc.strength = 2;
chip->ecc.hwctl = tmio_nand_enable_hwecc;
chip->ecc.calculate = tmio_nand_calculate_ecc;
chip->ecc.correct = tmio_nand_correct_data;
return 0;
}
static const struct nand_controller_ops tmio_ops = {
.attach_chip = tmio_attach_chip,
};
static int tmio_probe(struct platform_device *dev)
{
struct tmio_nand_data *data = dev_get_platdata(&dev->dev);
struct resource *fcr = platform_get_resource(dev,
IORESOURCE_MEM, 0);
struct resource *ccr = platform_get_resource(dev,
IORESOURCE_MEM, 1);
int irq = platform_get_irq(dev, 0);
struct tmio_nand *tmio;
struct mtd_info *mtd;
struct nand_chip *nand_chip;
int retval;
if (data == NULL)
dev_warn(&dev->dev, "NULL platform data!\n");
tmio = devm_kzalloc(&dev->dev, sizeof(*tmio), GFP_KERNEL);
if (!tmio)
return -ENOMEM;
init_completion(&tmio->comp);
tmio->dev = dev;
platform_set_drvdata(dev, tmio);
nand_chip = &tmio->chip;
mtd = nand_to_mtd(nand_chip);
mtd->name = "tmio-nand";
mtd->dev.parent = &dev->dev;
nand_controller_init(&tmio->controller);
tmio->controller.ops = &tmio_ops;
nand_chip->controller = &tmio->controller;
tmio->ccr = devm_ioremap(&dev->dev, ccr->start, resource_size(ccr));
if (!tmio->ccr)
return -EIO;
tmio->fcr_base = fcr->start & 0xfffff;
tmio->fcr = devm_ioremap(&dev->dev, fcr->start, resource_size(fcr));
if (!tmio->fcr)
return -EIO;
retval = tmio_hw_init(dev, tmio);
if (retval)
return retval;
/* Set address of NAND IO lines */
nand_chip->legacy.IO_ADDR_R = tmio->fcr;
nand_chip->legacy.IO_ADDR_W = tmio->fcr;
/* Set address of hardware control function */
nand_chip->legacy.cmd_ctrl = tmio_nand_hwcontrol;
nand_chip->legacy.dev_ready = tmio_nand_dev_ready;
nand_chip->legacy.read_byte = tmio_nand_read_byte;
nand_chip->legacy.write_buf = tmio_nand_write_buf;
nand_chip->legacy.read_buf = tmio_nand_read_buf;
if (data)
nand_chip->badblock_pattern = data->badblock_pattern;
/* 15 us command delay time */
nand_chip->legacy.chip_delay = 15;
retval = devm_request_irq(&dev->dev, irq, &tmio_irq, 0,
dev_name(&dev->dev), tmio);
if (retval) {
dev_err(&dev->dev, "request_irq error %d\n", retval);
goto err_irq;
}
tmio->irq = irq;
nand_chip->legacy.waitfunc = tmio_nand_wait;
/* Scan to find existence of the device */
retval = nand_scan(nand_chip, 1);
if (retval)
goto err_irq;
/* Register the partitions */
retval = mtd_device_parse_register(mtd,
data ? data->part_parsers : NULL,
NULL,
data ? data->partition : NULL,
data ? data->num_partitions : 0);
if (!retval)
return retval;
nand_cleanup(nand_chip);
err_irq:
tmio_hw_stop(dev, tmio);
return retval;
}
static int tmio_remove(struct platform_device *dev)
{
struct tmio_nand *tmio = platform_get_drvdata(dev);
struct nand_chip *chip = &tmio->chip;
int ret;
ret = mtd_device_unregister(nand_to_mtd(chip));
WARN_ON(ret);
nand_cleanup(chip);
tmio_hw_stop(dev, tmio);
return 0;
}
#ifdef CONFIG_PM
static int tmio_suspend(struct platform_device *dev, pm_message_t state)
{
const struct mfd_cell *cell = mfd_get_cell(dev);
if (cell->suspend)
cell->suspend(dev);
tmio_hw_stop(dev, platform_get_drvdata(dev));
return 0;
}
static int tmio_resume(struct platform_device *dev)
{
const struct mfd_cell *cell = mfd_get_cell(dev);
/* FIXME - is this required or merely another attack of the broken
* SHARP platform? Looks suspicious.
*/
tmio_hw_init(dev, platform_get_drvdata(dev));
if (cell->resume)
cell->resume(dev);
return 0;
}
#else
#define tmio_suspend NULL
#define tmio_resume NULL
#endif
static struct platform_driver tmio_driver = {
.driver.name = "tmio-nand",
.driver.owner = THIS_MODULE,
.probe = tmio_probe,
.remove = tmio_remove,
.suspend = tmio_suspend,
.resume = tmio_resume,
};
module_platform_driver(tmio_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Ian Molton, Dirk Opfer, Chris Humbert, Dmitry Baryshkov");
MODULE_DESCRIPTION("NAND flash driver on Toshiba Mobile IO controller");
MODULE_ALIAS("platform:tmio-nand");
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