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
35 struct nand_hw_control base
;
36 void __iomem
*io_base
;
38 struct nand_chip
*chips
[OXNAS_NAND_MAX_CHIPS
];
40 struct mtd_partition
*partitions
;
44 static uint8_t oxnas_nand_read_byte(struct mtd_info
*mtd
)
46 struct nand_chip
*chip
= mtd_to_nand(mtd
);
47 struct oxnas_nand
*oxnas
= nand_get_controller_data(chip
);
49 return readb(oxnas
->io_base
);
52 static void oxnas_nand_read_buf(struct mtd_info
*mtd
, uint8_t *buf
, int len
)
54 struct nand_chip
*chip
= mtd_to_nand(mtd
);
55 struct oxnas_nand
*oxnas
= nand_get_controller_data(chip
);
57 ioread8_rep(oxnas
->io_base
, buf
, len
);
60 static void oxnas_nand_write_buf(struct mtd_info
*mtd
,
61 const uint8_t *buf
, int len
)
63 struct nand_chip
*chip
= mtd_to_nand(mtd
);
64 struct oxnas_nand
*oxnas
= nand_get_controller_data(chip
);
66 iowrite8_rep(oxnas
->io_base
+ oxnas
->ctrl
, buf
, len
);
69 /* Single CS command control */
70 static void oxnas_nand_cmd_ctrl(struct mtd_info
*mtd
, int cmd
,
73 struct nand_chip
*chip
= mtd_to_nand(mtd
);
74 struct oxnas_nand
*oxnas
= nand_get_controller_data(chip
);
76 if (ctrl
& NAND_CTRL_CHANGE
) {
78 oxnas
->ctrl
= OXNAS_NAND_CMD_CLE
;
79 else if (ctrl
& NAND_ALE
)
80 oxnas
->ctrl
= OXNAS_NAND_CMD_ALE
;
85 if (cmd
!= NAND_CMD_NONE
)
86 writeb(cmd
, oxnas
->io_base
+ oxnas
->ctrl
);
90 * Probe for the NAND device.
92 static int oxnas_nand_probe(struct platform_device
*pdev
)
94 struct device_node
*np
= pdev
->dev
.of_node
;
95 struct device_node
*nand_np
;
96 struct oxnas_nand
*oxnas
;
97 struct nand_chip
*chip
;
104 /* Allocate memory for the device structure (and zero it) */
105 oxnas
= devm_kzalloc(&pdev
->dev
, sizeof(struct nand_chip
),
110 nand_hw_control_init(&oxnas
->base
);
112 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
113 oxnas
->io_base
= devm_ioremap_resource(&pdev
->dev
, res
);
114 if (IS_ERR(oxnas
->io_base
))
115 return PTR_ERR(oxnas
->io_base
);
117 oxnas
->clk
= devm_clk_get(&pdev
->dev
, NULL
);
118 if (IS_ERR(oxnas
->clk
))
121 /* Only a single chip node is supported */
122 count
= of_get_child_count(np
);
123 pr_info("########### count: %d\n", count
);
127 clk_prepare_enable(oxnas
->clk
);
128 device_reset_optional(&pdev
->dev
);
130 for_each_child_of_node(np
, nand_np
) {
131 chip
= devm_kzalloc(&pdev
->dev
, sizeof(struct nand_chip
),
136 chip
->controller
= &oxnas
->base
;
138 nand_set_flash_node(chip
, nand_np
);
139 nand_set_controller_data(chip
, oxnas
);
141 mtd
= nand_to_mtd(chip
);
142 mtd
->dev
.parent
= &pdev
->dev
;
145 chip
->cmd_ctrl
= oxnas_nand_cmd_ctrl
;
146 chip
->read_buf
= oxnas_nand_read_buf
;
147 chip
->read_byte
= oxnas_nand_read_byte
;
148 chip
->write_buf
= oxnas_nand_write_buf
;
149 chip
->chip_delay
= 30;
151 /* Scan to find existence of the device */
152 err
= nand_scan(mtd
, 1);
153 pr_info("########### nand_scan err: %d\n", err
);
157 err
= mtd_device_register(mtd
, NULL
, 0);
158 pr_info("########### mtd_device_register err: %d\n", err
);
164 oxnas
->chips
[nchips
] = chip
;
168 pr_info("########### nchips: %d\n", nchips
);
170 /* Exit if no chips found */
174 platform_set_drvdata(pdev
, oxnas
);
179 static int oxnas_nand_remove(struct platform_device
*pdev
)
181 struct oxnas_nand
*oxnas
= platform_get_drvdata(pdev
);
184 nand_release(nand_to_mtd(oxnas
->chips
[0]));
186 clk_disable_unprepare(oxnas
->clk
);
191 static const struct of_device_id oxnas_nand_match
[] = {
192 { .compatible
= "oxsemi,ox820-nand" },
195 MODULE_DEVICE_TABLE(of
, oxnas_nand_match
);
197 static struct platform_driver oxnas_nand_driver
= {
198 .probe
= oxnas_nand_probe
,
199 .remove
= oxnas_nand_remove
,
201 .name
= "oxnas_nand",
202 .of_match_table
= oxnas_nand_match
,
206 module_platform_driver(oxnas_nand_driver
);
208 MODULE_LICENSE("GPL");
209 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
210 MODULE_DESCRIPTION("Oxnas NAND driver");
211 MODULE_ALIAS("platform:oxnas_nand");