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/rawnand.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];
42 static uint8_t oxnas_nand_read_byte(struct mtd_info *mtd)
44 struct nand_chip *chip = mtd_to_nand(mtd);
45 struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
47 return readb(oxnas->io_base);
50 static void oxnas_nand_read_buf(struct mtd_info *mtd, u8 *buf, int len)
52 struct nand_chip *chip = mtd_to_nand(mtd);
53 struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
55 ioread8_rep(oxnas->io_base, buf, len);
58 static void oxnas_nand_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
60 struct nand_chip *chip = mtd_to_nand(mtd);
61 struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
63 iowrite8_rep(oxnas->io_base, buf, len);
66 /* Single CS command control */
67 static void oxnas_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
70 struct nand_chip *chip = mtd_to_nand(mtd);
71 struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
74 writeb(cmd, oxnas->io_base + OXNAS_NAND_CMD_CLE);
75 else if (ctrl & NAND_ALE)
76 writeb(cmd, oxnas->io_base + OXNAS_NAND_CMD_ALE);
80 * Probe for the NAND device.
82 static int oxnas_nand_probe(struct platform_device *pdev)
84 struct device_node *np = pdev->dev.of_node;
85 struct device_node *nand_np;
86 struct oxnas_nand_ctrl *oxnas;
87 struct nand_chip *chip;
94 /* Allocate memory for the device structure (and zero it) */
95 oxnas = devm_kzalloc(&pdev->dev, sizeof(*oxnas),
100 nand_hw_control_init(&oxnas->base);
102 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
103 oxnas->io_base = devm_ioremap_resource(&pdev->dev, res);
104 if (IS_ERR(oxnas->io_base))
105 return PTR_ERR(oxnas->io_base);
107 oxnas->clk = devm_clk_get(&pdev->dev, NULL);
108 if (IS_ERR(oxnas->clk))
111 /* Only a single chip node is supported */
112 count = of_get_child_count(np);
116 err = clk_prepare_enable(oxnas->clk);
120 device_reset_optional(&pdev->dev);
122 for_each_child_of_node(np, nand_np) {
123 chip = devm_kzalloc(&pdev->dev, sizeof(struct nand_chip),
127 goto err_release_child;
130 chip->controller = &oxnas->base;
132 nand_set_flash_node(chip, nand_np);
133 nand_set_controller_data(chip, oxnas);
135 mtd = nand_to_mtd(chip);
136 mtd->dev.parent = &pdev->dev;
139 chip->cmd_ctrl = oxnas_nand_cmd_ctrl;
140 chip->read_buf = oxnas_nand_read_buf;
141 chip->read_byte = oxnas_nand_read_byte;
142 chip->write_buf = oxnas_nand_write_buf;
143 chip->chip_delay = 30;
145 /* Scan to find existence of the device */
146 err = nand_scan(mtd, 1);
148 goto err_release_child;
150 err = mtd_device_register(mtd, NULL, 0);
152 goto err_cleanup_nand;
154 oxnas->chips[oxnas->nchips] = chip;
158 /* Exit if no chips found */
159 if (!oxnas->nchips) {
161 goto err_clk_unprepare;
164 platform_set_drvdata(pdev, oxnas);
171 of_node_put(nand_np);
173 for (i = 0; i < oxnas->nchips; i++) {
174 chip = oxnas->chips[i];
175 WARN_ON(mtd_device_unregister(nand_to_mtd(chip)));
180 clk_disable_unprepare(oxnas->clk);
184 static int oxnas_nand_remove(struct platform_device *pdev)
186 struct oxnas_nand_ctrl *oxnas = platform_get_drvdata(pdev);
187 struct nand_chip *chip;
190 for (i = 0; i < oxnas->nchips; i++) {
191 chip = oxnas->chips[i];
195 clk_disable_unprepare(oxnas->clk);
200 static const struct of_device_id oxnas_nand_match[] = {
201 { .compatible = "oxsemi,ox820-nand" },
204 MODULE_DEVICE_TABLE(of, oxnas_nand_match);
206 static struct platform_driver oxnas_nand_driver = {
207 .probe = oxnas_nand_probe,
208 .remove = oxnas_nand_remove,
210 .name = "oxnas_nand",
211 .of_match_table = oxnas_nand_match,
215 module_platform_driver(oxnas_nand_driver);
217 MODULE_LICENSE("GPL");
218 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
219 MODULE_DESCRIPTION("Oxnas NAND driver");
220 MODULE_ALIAS("platform:oxnas_nand");