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/*
* 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.
*
* Copyright © 2012 John Crispin <blogic@openwrt.org>
* Copyright © 2016 Hauke Mehrtens <hauke@hauke-m.de>
*/
#include <linux/mtd/nand.h>
#include <linux/of_gpio.h>
#include <linux/of_platform.h>
#include <lantiq_soc.h>
/* nand registers */
#define EBU_ADDSEL1 0x24
#define EBU_NAND_CON 0xB0
#define EBU_NAND_WAIT 0xB4
#define NAND_WAIT_RD BIT(0) /* NAND flash status output */
#define NAND_WAIT_WR_C BIT(3) /* NAND Write/Read complete */
#define EBU_NAND_ECC0 0xB8
#define EBU_NAND_ECC_AC 0xBC
/*
* nand commands
* The pins of the NAND chip are selected based on the address bits of the
* "register" read and write. There are no special registers, but an
* address range and the lower address bits are used to activate the
* correct line. For example when the bit (1 << 2) is set in the address
* the ALE pin will be activated.
*/
#define NAND_CMD_ALE BIT(2) /* address latch enable */
#define NAND_CMD_CLE BIT(3) /* command latch enable */
#define NAND_CMD_CS BIT(4) /* chip select */
#define NAND_CMD_SE BIT(5) /* spare area access latch */
#define NAND_CMD_WP BIT(6) /* write protect */
#define NAND_WRITE_CMD (NAND_CMD_CS | NAND_CMD_CLE)
#define NAND_WRITE_ADDR (NAND_CMD_CS | NAND_CMD_ALE)
#define NAND_WRITE_DATA (NAND_CMD_CS)
#define NAND_READ_DATA (NAND_CMD_CS)
/* we need to tel the ebu which addr we mapped the nand to */
#define ADDSEL1_MASK(x) (x << 4)
#define ADDSEL1_REGEN 1
/* we need to tell the EBU that we have nand attached and set it up properly */
#define BUSCON1_SETUP (1 << 22)
#define BUSCON1_BCGEN_RES (0x3 << 12)
#define BUSCON1_WAITWRC2 (2 << 8)
#define BUSCON1_WAITRDC2 (2 << 6)
#define BUSCON1_HOLDC1 (1 << 4)
#define BUSCON1_RECOVC1 (1 << 2)
#define BUSCON1_CMULT4 1
#define NAND_CON_CE (1 << 20)
#define NAND_CON_OUT_CS1 (1 << 10)
#define NAND_CON_IN_CS1 (1 << 8)
#define NAND_CON_PRE_P (1 << 7)
#define NAND_CON_WP_P (1 << 6)
#define NAND_CON_SE_P (1 << 5)
#define NAND_CON_CS_P (1 << 4)
#define NAND_CON_CSMUX (1 << 1)
#define NAND_CON_NANDM 1
struct xway_nand_data {
struct nand_chip chip;
unsigned long csflags;
void __iomem *nandaddr;
};
static u8 xway_readb(struct mtd_info *mtd, int op)
{
struct nand_chip *chip = mtd_to_nand(mtd);
struct xway_nand_data *data = nand_get_controller_data(chip);
return readb(data->nandaddr + op);
}
static void xway_writeb(struct mtd_info *mtd, int op, u8 value)
{
struct nand_chip *chip = mtd_to_nand(mtd);
struct xway_nand_data *data = nand_get_controller_data(chip);
writeb(value, data->nandaddr + op);
}
static void xway_select_chip(struct mtd_info *mtd, int select)
{
struct nand_chip *chip = mtd_to_nand(mtd);
struct xway_nand_data *data = nand_get_controller_data(chip);
switch (select) {
case -1:
ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
spin_unlock_irqrestore(&ebu_lock, data->csflags);
break;
case 0:
spin_lock_irqsave(&ebu_lock, data->csflags);
ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
break;
default:
BUG();
}
}
static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
if (cmd == NAND_CMD_NONE)
return;
if (ctrl & NAND_CLE)
xway_writeb(mtd, NAND_WRITE_CMD, cmd);
else if (ctrl & NAND_ALE)
xway_writeb(mtd, NAND_WRITE_ADDR, cmd);
while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
;
}
static int xway_dev_ready(struct mtd_info *mtd)
{
return ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_RD;
}
static unsigned char xway_read_byte(struct mtd_info *mtd)
{
return xway_readb(mtd, NAND_READ_DATA);
}
static void xway_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
int i;
for (i = 0; i < len; i++)
buf[i] = xway_readb(mtd, NAND_WRITE_DATA);
}
static void xway_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
int i;
for (i = 0; i < len; i++)
xway_writeb(mtd, NAND_WRITE_DATA, buf[i]);
}
/*
* Probe for the NAND device.
*/
static int xway_nand_probe(struct platform_device *pdev)
{
struct xway_nand_data *data;
struct mtd_info *mtd;
struct resource *res;
int err;
u32 cs;
u32 cs_flag = 0;
/* Allocate memory for the device structure (and zero it) */
data = devm_kzalloc(&pdev->dev, sizeof(struct xway_nand_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
data->nandaddr = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(data->nandaddr))
return PTR_ERR(data->nandaddr);
nand_set_flash_node(&data->chip, pdev->dev.of_node);
mtd = nand_to_mtd(&data->chip);
mtd->dev.parent = &pdev->dev;
data->chip.cmd_ctrl = xway_cmd_ctrl;
data->chip.dev_ready = xway_dev_ready;
data->chip.select_chip = xway_select_chip;
data->chip.write_buf = xway_write_buf;
data->chip.read_buf = xway_read_buf;
data->chip.read_byte = xway_read_byte;
data->chip.chip_delay = 30;
data->chip.ecc.mode = NAND_ECC_SOFT;
data->chip.ecc.algo = NAND_ECC_HAMMING;
platform_set_drvdata(pdev, data);
nand_set_controller_data(&data->chip, data);
/* load our CS from the DT. Either we find a valid 1 or default to 0 */
err = of_property_read_u32(pdev->dev.of_node, "lantiq,cs", &cs);
if (!err && cs == 1)
cs_flag = NAND_CON_IN_CS1 | NAND_CON_OUT_CS1;
/* setup the EBU to run in NAND mode on our base addr */
ltq_ebu_w32(CPHYSADDR(data->nandaddr)
| ADDSEL1_MASK(3) | ADDSEL1_REGEN, EBU_ADDSEL1);
ltq_ebu_w32(BUSCON1_SETUP | BUSCON1_BCGEN_RES | BUSCON1_WAITWRC2
| BUSCON1_WAITRDC2 | BUSCON1_HOLDC1 | BUSCON1_RECOVC1
| BUSCON1_CMULT4, LTQ_EBU_BUSCON1);
ltq_ebu_w32(NAND_CON_NANDM | NAND_CON_CSMUX | NAND_CON_CS_P
| NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
| cs_flag, EBU_NAND_CON);
/* Scan to find existence of the device */
err = nand_scan(mtd, 1);
if (err)
return err;
err = mtd_device_register(mtd, NULL, 0);
if (err)
nand_release(mtd);
return err;
}
/*
* Remove a NAND device.
*/
static int xway_nand_remove(struct platform_device *pdev)
{
struct xway_nand_data *data = platform_get_drvdata(pdev);
nand_release(nand_to_mtd(&data->chip));
return 0;
}
static const struct of_device_id xway_nand_match[] = {
{ .compatible = "lantiq,nand-xway" },
{},
};
MODULE_DEVICE_TABLE(of, xway_nand_match);
static struct platform_driver xway_nand_driver = {
.probe = xway_nand_probe,
.remove = xway_nand_remove,
.driver = {
.name = "lantiq,nand-xway",
.of_match_table = xway_nand_match,
},
};
module_platform_driver(xway_nand_driver);
MODULE_LICENSE("GPL");
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