2 * This program is free software; you can redistribute it and/or modify it
3 * under the terms of the GNU General Public License version 2 as published
4 * by the Free Software Foundation.
7 * Copyright © 2012 John Crispin <blogic@openwrt.org>
8 * and oxnas_nand.c "NAND glue for Oxnas platforms"
9 * written by Ma Haijun <mahaijuns@gmail.com>
12 #include <linux/mtd/nand.h>
13 #include <linux/of_gpio.h>
14 #include <linux/of_platform.h>
15 #include <linux/clk.h>
16 #include <linux/reset.h>
19 #define NAND_CMD_ALE BIT(18)
20 #define NAND_CMD_CLE BIT(19)
22 #define NAND_CMD_RESET 0xff
23 #define NAND_CMD (NAND_CMD_CS | NAND_CMD_CLE)
24 #define NAND_ADDR (NAND_CMD_CS | NAND_CMD_ALE)
25 #define NAND_DATA (NAND_CMD_CS)
27 static void oxnas_cmd_ctrl(struct mtd_info
*mtd
, int cmd
, unsigned int ctrl
)
29 struct nand_chip
*this = mtd
->priv
;
30 unsigned long nandaddr
= (unsigned long) this->IO_ADDR_W
;
32 if (ctrl
& NAND_CTRL_CHANGE
) {
33 nandaddr
&= ~(NAND_CMD
| NAND_ADDR
);
36 else if (ctrl
& NAND_ALE
)
37 nandaddr
|= NAND_ADDR
;
38 this->IO_ADDR_W
= (void __iomem
*) nandaddr
;
41 if (cmd
!= NAND_CMD_NONE
)
42 writeb(cmd
, (void __iomem
*) nandaddr
);
45 static int oxnas_nand_probe(struct platform_device
*pdev
)
47 /* enable clock and release static block reset */
48 struct clk
*clk
= of_clk_get(pdev
->dev
.of_node
, 0);
53 clk_prepare_enable(clk
);
54 device_reset(&pdev
->dev
);
59 /* allow users to override the partition in DT using the cmdline */
60 static const char * part_probes
[] = { "cmdlinepart", "ofpart", NULL
};
62 static struct platform_nand_data oxnas_nand_data
= {
66 .part_probe_types
= part_probes
,
69 .probe
= oxnas_nand_probe
,
70 .cmd_ctrl
= oxnas_cmd_ctrl
,
75 * Try to find the node inside the DT. If it is available attach out
78 static int __init
oxnas_register_nand(void)
80 struct device_node
*node
;
81 struct platform_device
*pdev
;
83 node
= of_find_compatible_node(NULL
, NULL
, "plxtech,nand-nas782x");
86 pdev
= of_find_device_by_node(node
);
89 pdev
->dev
.platform_data
= &oxnas_nand_data
;
94 subsys_initcall(oxnas_register_nand
);