2 * Oxford Semiconductor OXNAS NAND driver
4 * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
5 * Heavily based on plat_nand.c :
6 * Author: Vitaly Wool <vitalywool@gmail.com>
7 * Copyright (C) 2013 Ma Haijun <mahaijuns@gmail.com>
8 * Copyright (C) 2012 John Crispin <blogic@openwrt.org>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
16 #include <linux/err.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/slab.h>
21 #include <linux/clk.h>
22 #include <linux/reset.h>
23 #include <linux/mtd/mtd.h>
24 #include <linux/mtd/nand.h>
25 #include <linux/mtd/partitions.h>
29 #define OXNAS_NAND_CMD_ALE BIT(18)
30 #define OXNAS_NAND_CMD_CLE BIT(19)
32 #define OXNAS_NAND_MAX_CHIPS 1
34 struct oxnas_nand_ctrl
{
35 struct nand_hw_control base
;
36 void __iomem
*io_base
;
38 struct nand_chip
*chips
[OXNAS_NAND_MAX_CHIPS
];
41 static uint8_t oxnas_nand_read_byte(struct mtd_info
*mtd
)
43 struct nand_chip
*chip
= mtd_to_nand(mtd
);
44 struct oxnas_nand_ctrl
*oxnas
= nand_get_controller_data(chip
);
46 return readb(oxnas
->io_base
);
49 static void oxnas_nand_read_buf(struct mtd_info
*mtd
, u8
*buf
, int len
)
51 struct nand_chip
*chip
= mtd_to_nand(mtd
);
52 struct oxnas_nand_ctrl
*oxnas
= nand_get_controller_data(chip
);
54 ioread8_rep(oxnas
->io_base
, buf
, len
);
57 static void oxnas_nand_write_buf(struct mtd_info
*mtd
, const u8
*buf
, int len
)
59 struct nand_chip
*chip
= mtd_to_nand(mtd
);
60 struct oxnas_nand_ctrl
*oxnas
= nand_get_controller_data(chip
);
62 iowrite8_rep(oxnas
->io_base
, buf
, len
);
65 /* Single CS command control */
66 static void oxnas_nand_cmd_ctrl(struct mtd_info
*mtd
, int cmd
,
69 struct nand_chip
*chip
= mtd_to_nand(mtd
);
70 struct oxnas_nand_ctrl
*oxnas
= nand_get_controller_data(chip
);
73 writeb(cmd
, oxnas
->io_base
+ OXNAS_NAND_CMD_CLE
);
74 else if (ctrl
& NAND_ALE
)
75 writeb(cmd
, oxnas
->io_base
+ OXNAS_NAND_CMD_ALE
);
79 * Probe for the NAND device.
81 static int oxnas_nand_probe(struct platform_device
*pdev
)
83 struct device_node
*np
= pdev
->dev
.of_node
;
84 struct device_node
*nand_np
;
85 struct oxnas_nand_ctrl
*oxnas
;
86 struct nand_chip
*chip
;
93 /* Allocate memory for the device structure (and zero it) */
94 oxnas
= devm_kzalloc(&pdev
->dev
, sizeof(*oxnas
),
99 nand_hw_control_init(&oxnas
->base
);
101 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
102 oxnas
->io_base
= devm_ioremap_resource(&pdev
->dev
, res
);
103 if (IS_ERR(oxnas
->io_base
))
104 return PTR_ERR(oxnas
->io_base
);
106 oxnas
->clk
= devm_clk_get(&pdev
->dev
, NULL
);
107 if (IS_ERR(oxnas
->clk
))
110 /* Only a single chip node is supported */
111 count
= of_get_child_count(np
);
115 clk_prepare_enable(oxnas
->clk
);
116 device_reset_optional(&pdev
->dev
);
118 for_each_child_of_node(np
, nand_np
) {
119 chip
= devm_kzalloc(&pdev
->dev
, sizeof(struct nand_chip
),
124 chip
->controller
= &oxnas
->base
;
126 nand_set_flash_node(chip
, nand_np
);
127 nand_set_controller_data(chip
, oxnas
);
129 mtd
= nand_to_mtd(chip
);
130 mtd
->dev
.parent
= &pdev
->dev
;
133 chip
->cmd_ctrl
= oxnas_nand_cmd_ctrl
;
134 chip
->read_buf
= oxnas_nand_read_buf
;
135 chip
->read_byte
= oxnas_nand_read_byte
;
136 chip
->write_buf
= oxnas_nand_write_buf
;
137 chip
->chip_delay
= 30;
139 /* Scan to find existence of the device */
140 err
= nand_scan(mtd
, 1);
144 err
= mtd_device_register(mtd
, NULL
, 0);
150 oxnas
->chips
[nchips
] = chip
;
154 /* Exit if no chips found */
158 platform_set_drvdata(pdev
, oxnas
);
163 static int oxnas_nand_remove(struct platform_device
*pdev
)
165 struct oxnas_nand_ctrl
*oxnas
= platform_get_drvdata(pdev
);
168 nand_release(nand_to_mtd(oxnas
->chips
[0]));
170 clk_disable_unprepare(oxnas
->clk
);
175 static const struct of_device_id oxnas_nand_match
[] = {
176 { .compatible
= "oxsemi,ox820-nand" },
179 MODULE_DEVICE_TABLE(of
, oxnas_nand_match
);
181 static struct platform_driver oxnas_nand_driver
= {
182 .probe
= oxnas_nand_probe
,
183 .remove
= oxnas_nand_remove
,
185 .name
= "oxnas_nand",
186 .of_match_table
= oxnas_nand_match
,
190 module_platform_driver(oxnas_nand_driver
);
192 MODULE_LICENSE("GPL");
193 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
194 MODULE_DESCRIPTION("Oxnas NAND driver");
195 MODULE_ALIAS("platform:oxnas_nand");