linux/drivers/mtd/nand/orion_nand.c
Simon Baatz ef980cf8b0 mtd: nand: orion: improve handling of optional clock
The clock gate used by orion_nand is not available on all platforms.
When getting this optional clock gate, the code masked all errors.
Let's be more precise here and actually only allow ENOENT.

EPROBE_DEFER is handled like any other error code since probe deferral
is not supported by drivers using module_platform_driver_probe().

Signed-off-by: Simon Baatz <gmbnomis@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
2017-03-29 17:05:37 +02:00

224 lines
5.1 KiB
C

/*
* drivers/mtd/nand/orion_nand.c
*
* NAND support for Marvell Orion SoC platforms
*
* Tzachi Perelstein <tzachi@marvell.com>
*
* 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/slab.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <asm/sizes.h>
#include <linux/platform_data/mtd-orion_nand.h>
struct orion_nand_info {
struct nand_chip chip;
struct clk *clk;
};
static void orion_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
struct nand_chip *nc = mtd_to_nand(mtd);
struct orion_nand_data *board = nand_get_controller_data(nc);
u32 offs;
if (cmd == NAND_CMD_NONE)
return;
if (ctrl & NAND_CLE)
offs = (1 << board->cle);
else if (ctrl & NAND_ALE)
offs = (1 << board->ale);
else
return;
if (nc->options & NAND_BUSWIDTH_16)
offs <<= 1;
writeb(cmd, nc->IO_ADDR_W + offs);
}
static void orion_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
{
struct nand_chip *chip = mtd_to_nand(mtd);
void __iomem *io_base = chip->IO_ADDR_R;
uint64_t *buf64;
int i = 0;
while (len && (unsigned long)buf & 7) {
*buf++ = readb(io_base);
len--;
}
buf64 = (uint64_t *)buf;
while (i < len/8) {
/*
* Since GCC has no proper constraint (PR 43518)
* force x variable to r2/r3 registers as ldrd instruction
* requires first register to be even.
*/
register uint64_t x asm ("r2");
asm volatile ("ldrd\t%0, [%1]" : "=&r" (x) : "r" (io_base));
buf64[i++] = x;
}
i *= 8;
while (i < len)
buf[i++] = readb(io_base);
}
static int __init orion_nand_probe(struct platform_device *pdev)
{
struct orion_nand_info *info;
struct mtd_info *mtd;
struct nand_chip *nc;
struct orion_nand_data *board;
struct resource *res;
void __iomem *io_base;
int ret = 0;
u32 val = 0;
info = devm_kzalloc(&pdev->dev,
sizeof(struct orion_nand_info),
GFP_KERNEL);
if (!info)
return -ENOMEM;
nc = &info->chip;
mtd = nand_to_mtd(nc);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
io_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(io_base))
return PTR_ERR(io_base);
if (pdev->dev.of_node) {
board = devm_kzalloc(&pdev->dev, sizeof(struct orion_nand_data),
GFP_KERNEL);
if (!board)
return -ENOMEM;
if (!of_property_read_u32(pdev->dev.of_node, "cle", &val))
board->cle = (u8)val;
else
board->cle = 0;
if (!of_property_read_u32(pdev->dev.of_node, "ale", &val))
board->ale = (u8)val;
else
board->ale = 1;
if (!of_property_read_u32(pdev->dev.of_node,
"bank-width", &val))
board->width = (u8)val * 8;
else
board->width = 8;
if (!of_property_read_u32(pdev->dev.of_node,
"chip-delay", &val))
board->chip_delay = (u8)val;
} else {
board = dev_get_platdata(&pdev->dev);
}
mtd->dev.parent = &pdev->dev;
nand_set_controller_data(nc, board);
nand_set_flash_node(nc, pdev->dev.of_node);
nc->IO_ADDR_R = nc->IO_ADDR_W = io_base;
nc->cmd_ctrl = orion_nand_cmd_ctrl;
nc->read_buf = orion_nand_read_buf;
nc->ecc.mode = NAND_ECC_SOFT;
nc->ecc.algo = NAND_ECC_HAMMING;
if (board->chip_delay)
nc->chip_delay = board->chip_delay;
WARN(board->width > 16,
"%d bit bus width out of range",
board->width);
if (board->width == 16)
nc->options |= NAND_BUSWIDTH_16;
if (board->dev_ready)
nc->dev_ready = board->dev_ready;
platform_set_drvdata(pdev, info);
/* Not all platforms can gate the clock, so it is not
an error if the clock does not exists. */
info->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(info->clk)) {
ret = PTR_ERR(info->clk);
if (ret == -ENOENT) {
info->clk = NULL;
} else {
dev_err(&pdev->dev, "failed to get clock!\n");
return ret;
}
}
clk_prepare_enable(info->clk);
ret = nand_scan(mtd, 1);
if (ret)
goto no_dev;
mtd->name = "orion_nand";
ret = mtd_device_register(mtd, board->parts, board->nr_parts);
if (ret) {
nand_release(mtd);
goto no_dev;
}
return 0;
no_dev:
clk_disable_unprepare(info->clk);
return ret;
}
static int orion_nand_remove(struct platform_device *pdev)
{
struct orion_nand_info *info = platform_get_drvdata(pdev);
struct nand_chip *chip = &info->chip;
struct mtd_info *mtd = nand_to_mtd(chip);
nand_release(mtd);
clk_disable_unprepare(info->clk);
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id orion_nand_of_match_table[] = {
{ .compatible = "marvell,orion-nand", },
{},
};
MODULE_DEVICE_TABLE(of, orion_nand_of_match_table);
#endif
static struct platform_driver orion_nand_driver = {
.remove = orion_nand_remove,
.driver = {
.name = "orion_nand",
.of_match_table = of_match_ptr(orion_nand_of_match_table),
},
};
module_platform_driver_probe(orion_nand_driver, orion_nand_probe);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Tzachi Perelstein");
MODULE_DESCRIPTION("NAND glue for Orion platforms");
MODULE_ALIAS("platform:orion_nand");