1 /*
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.
5 *
6 * Copyright © 2012 John Crispin <blogic@openwrt.org>
7 */
8
9 #include <linux/mtd/nand.h>
10 #include <linux/of_gpio.h>
11 #include <linux/of_platform.h>
12
13 #include <lantiq_soc.h>
14
15 /* nand registers */
16 #define EBU_ADDSEL1 0x24
17 #define EBU_NAND_CON 0xB0
18 #define EBU_NAND_WAIT 0xB4
19 #define EBU_NAND_ECC0 0xB8
20 #define EBU_NAND_ECC_AC 0xBC
21
22 /* nand commands */
23 #define NAND_CMD_ALE (1 << 2)
24 #define NAND_CMD_CLE (1 << 3)
25 #define NAND_CMD_CS (1 << 4)
26 #define NAND_WRITE_CMD_RESET 0xff
27 #define NAND_WRITE_CMD (NAND_CMD_CS | NAND_CMD_CLE)
28 #define NAND_WRITE_ADDR (NAND_CMD_CS | NAND_CMD_ALE)
29 #define NAND_WRITE_DATA (NAND_CMD_CS)
30 #define NAND_READ_DATA (NAND_CMD_CS)
31 #define NAND_WAIT_WR_C (1 << 3)
32 #define NAND_WAIT_RD (0x1)
33
34 /* we need to tel the ebu which addr we mapped the nand to */
35 #define ADDSEL1_MASK(x) (x << 4)
36 #define ADDSEL1_REGEN 1
37
38 /* we need to tell the EBU that we have nand attached and set it up properly */
39 #define BUSCON1_SETUP (1 << 22)
40 #define BUSCON1_BCGEN_RES (0x3 << 12)
41 #define BUSCON1_WAITWRC2 (2 << 8)
42 #define BUSCON1_WAITRDC2 (2 << 6)
43 #define BUSCON1_HOLDC1 (1 << 4)
44 #define BUSCON1_RECOVC1 (1 << 2)
45 #define BUSCON1_CMULT4 1
46
47 #define NAND_CON_CE (1 << 20)
48 #define NAND_CON_OUT_CS1 (1 << 10)
49 #define NAND_CON_IN_CS1 (1 << 8)
50 #define NAND_CON_PRE_P (1 << 7)
51 #define NAND_CON_WP_P (1 << 6)
52 #define NAND_CON_SE_P (1 << 5)
53 #define NAND_CON_CS_P (1 << 4)
54 #define NAND_CON_CSMUX (1 << 1)
55 #define NAND_CON_NANDM 1
56
xway_reset_chip(struct nand_chip * chip)57 static void xway_reset_chip(struct nand_chip *chip)
58 {
59 unsigned long nandaddr = (unsigned long) chip->IO_ADDR_W;
60 unsigned long flags;
61
62 nandaddr &= ~NAND_WRITE_ADDR;
63 nandaddr |= NAND_WRITE_CMD;
64
65 /* finish with a reset */
66 spin_lock_irqsave(&ebu_lock, flags);
67 writeb(NAND_WRITE_CMD_RESET, (void __iomem *) nandaddr);
68 while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
69 ;
70 spin_unlock_irqrestore(&ebu_lock, flags);
71 }
72
xway_select_chip(struct mtd_info * mtd,int chip)73 static void xway_select_chip(struct mtd_info *mtd, int chip)
74 {
75
76 switch (chip) {
77 case -1:
78 ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
79 ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
80 break;
81 case 0:
82 ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
83 ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
84 break;
85 default:
86 BUG();
87 }
88 }
89
xway_cmd_ctrl(struct mtd_info * mtd,int cmd,unsigned int ctrl)90 static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
91 {
92 struct nand_chip *this = mtd->priv;
93 unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
94 unsigned long flags;
95
96 if (ctrl & NAND_CTRL_CHANGE) {
97 nandaddr &= ~(NAND_WRITE_CMD | NAND_WRITE_ADDR);
98 if (ctrl & NAND_CLE)
99 nandaddr |= NAND_WRITE_CMD;
100 else
101 nandaddr |= NAND_WRITE_ADDR;
102 this->IO_ADDR_W = (void __iomem *) nandaddr;
103 }
104
105 if (cmd != NAND_CMD_NONE) {
106 spin_lock_irqsave(&ebu_lock, flags);
107 writeb(cmd, this->IO_ADDR_W);
108 while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
109 ;
110 spin_unlock_irqrestore(&ebu_lock, flags);
111 }
112 }
113
xway_dev_ready(struct mtd_info * mtd)114 static int xway_dev_ready(struct mtd_info *mtd)
115 {
116 return ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_RD;
117 }
118
xway_read_byte(struct mtd_info * mtd)119 static unsigned char xway_read_byte(struct mtd_info *mtd)
120 {
121 struct nand_chip *this = mtd->priv;
122 unsigned long nandaddr = (unsigned long) this->IO_ADDR_R;
123 unsigned long flags;
124 int ret;
125
126 spin_lock_irqsave(&ebu_lock, flags);
127 ret = ltq_r8((void __iomem *)(nandaddr + NAND_READ_DATA));
128 spin_unlock_irqrestore(&ebu_lock, flags);
129
130 return ret;
131 }
132
xway_nand_probe(struct platform_device * pdev)133 static int xway_nand_probe(struct platform_device *pdev)
134 {
135 struct nand_chip *this = platform_get_drvdata(pdev);
136 unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
137 const __be32 *cs = of_get_property(pdev->dev.of_node,
138 "lantiq,cs", NULL);
139 u32 cs_flag = 0;
140
141 /* load our CS from the DT. Either we find a valid 1 or default to 0 */
142 if (cs && (*cs == 1))
143 cs_flag = NAND_CON_IN_CS1 | NAND_CON_OUT_CS1;
144
145 /* setup the EBU to run in NAND mode on our base addr */
146 ltq_ebu_w32(CPHYSADDR(nandaddr)
147 | ADDSEL1_MASK(3) | ADDSEL1_REGEN, EBU_ADDSEL1);
148
149 ltq_ebu_w32(BUSCON1_SETUP | BUSCON1_BCGEN_RES | BUSCON1_WAITWRC2
150 | BUSCON1_WAITRDC2 | BUSCON1_HOLDC1 | BUSCON1_RECOVC1
151 | BUSCON1_CMULT4, LTQ_EBU_BUSCON1);
152
153 ltq_ebu_w32(NAND_CON_NANDM | NAND_CON_CSMUX | NAND_CON_CS_P
154 | NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
155 | cs_flag, EBU_NAND_CON);
156
157 /* finish with a reset */
158 xway_reset_chip(this);
159
160 return 0;
161 }
162
163 /* allow users to override the partition in DT using the cmdline */
164 static const char *part_probes[] = { "cmdlinepart", "ofpart", NULL };
165
166 static struct platform_nand_data xway_nand_data = {
167 .chip = {
168 .nr_chips = 1,
169 .chip_delay = 30,
170 .part_probe_types = part_probes,
171 },
172 .ctrl = {
173 .probe = xway_nand_probe,
174 .cmd_ctrl = xway_cmd_ctrl,
175 .dev_ready = xway_dev_ready,
176 .select_chip = xway_select_chip,
177 .read_byte = xway_read_byte,
178 }
179 };
180
181 /*
182 * Try to find the node inside the DT. If it is available attach out
183 * platform_nand_data
184 */
xway_register_nand(void)185 static int __init xway_register_nand(void)
186 {
187 struct device_node *node;
188 struct platform_device *pdev;
189
190 node = of_find_compatible_node(NULL, NULL, "lantiq,nand-xway");
191 if (!node)
192 return -ENOENT;
193 pdev = of_find_device_by_node(node);
194 if (!pdev)
195 return -EINVAL;
196 pdev->dev.platform_data = &xway_nand_data;
197 of_node_put(node);
198 return 0;
199 }
200
201 subsys_initcall(xway_register_nand);
202