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");