1 /*
2 * gpmc-nand.c
3 *
4 * Copyright (C) 2009 Texas Instruments
5 * Vimal Singh <vimalsingh@ti.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/platform_device.h>
14 #include <linux/io.h>
15 #include <linux/omap-gpmc.h>
16 #include <linux/mtd/nand.h>
17 #include <linux/platform_data/mtd-nand-omap2.h>
18
19 #include <asm/mach/flash.h>
20
21 #include "soc.h"
22
23 /* minimum size for IO mapping */
24 #define NAND_IO_SIZE 4
25
gpmc_hwecc_bch_capable(enum omap_ecc ecc_opt)26 static bool gpmc_hwecc_bch_capable(enum omap_ecc ecc_opt)
27 {
28 /* platforms which support all ECC schemes */
29 if (soc_is_am33xx() || soc_is_am43xx() || cpu_is_omap44xx() ||
30 soc_is_omap54xx() || soc_is_dra7xx())
31 return 1;
32
33 if (ecc_opt == OMAP_ECC_BCH4_CODE_HW_DETECTION_SW ||
34 ecc_opt == OMAP_ECC_BCH8_CODE_HW_DETECTION_SW) {
35 if (cpu_is_omap24xx())
36 return 0;
37 else if (cpu_is_omap3630() && (GET_OMAP_REVISION() == 0))
38 return 0;
39 else
40 return 1;
41 }
42
43 /* OMAP3xxx do not have ELM engine, so cannot support ECC schemes
44 * which require H/W based ECC error detection */
45 if ((cpu_is_omap34xx() || cpu_is_omap3630()) &&
46 ((ecc_opt == OMAP_ECC_BCH4_CODE_HW) ||
47 (ecc_opt == OMAP_ECC_BCH8_CODE_HW)))
48 return 0;
49
50 /* legacy platforms support only HAM1 (1-bit Hamming) ECC scheme */
51 if (ecc_opt == OMAP_ECC_HAM1_CODE_HW ||
52 ecc_opt == OMAP_ECC_HAM1_CODE_SW)
53 return 1;
54 else
55 return 0;
56 }
57
58 /* This function will go away once the device-tree convertion is complete */
gpmc_set_legacy(struct omap_nand_platform_data * gpmc_nand_data,struct gpmc_settings * s)59 static void gpmc_set_legacy(struct omap_nand_platform_data *gpmc_nand_data,
60 struct gpmc_settings *s)
61 {
62 /* Enable RD PIN Monitoring Reg */
63 if (gpmc_nand_data->dev_ready) {
64 s->wait_on_read = true;
65 s->wait_on_write = true;
66 }
67
68 if (gpmc_nand_data->devsize == NAND_BUSWIDTH_16)
69 s->device_width = GPMC_DEVWIDTH_16BIT;
70 else
71 s->device_width = GPMC_DEVWIDTH_8BIT;
72 }
73
gpmc_nand_init(struct omap_nand_platform_data * gpmc_nand_data,struct gpmc_timings * gpmc_t)74 int gpmc_nand_init(struct omap_nand_platform_data *gpmc_nand_data,
75 struct gpmc_timings *gpmc_t)
76 {
77 int err = 0;
78 struct gpmc_settings s;
79 struct platform_device *pdev;
80 struct resource gpmc_nand_res[] = {
81 { .flags = IORESOURCE_MEM, },
82 { .flags = IORESOURCE_IRQ, },
83 { .flags = IORESOURCE_IRQ, },
84 };
85
86 BUG_ON(gpmc_nand_data->cs >= GPMC_CS_NUM);
87
88 err = gpmc_cs_request(gpmc_nand_data->cs, NAND_IO_SIZE,
89 (unsigned long *)&gpmc_nand_res[0].start);
90 if (err < 0) {
91 pr_err("omap2-gpmc: Cannot request GPMC CS %d, error %d\n",
92 gpmc_nand_data->cs, err);
93 return err;
94 }
95 gpmc_nand_res[0].end = gpmc_nand_res[0].start + NAND_IO_SIZE - 1;
96 gpmc_nand_res[1].start = gpmc_get_client_irq(GPMC_IRQ_FIFOEVENTENABLE);
97 gpmc_nand_res[2].start = gpmc_get_client_irq(GPMC_IRQ_COUNT_EVENT);
98
99 memset(&s, 0, sizeof(struct gpmc_settings));
100 if (gpmc_nand_data->of_node)
101 gpmc_read_settings_dt(gpmc_nand_data->of_node, &s);
102 else
103 gpmc_set_legacy(gpmc_nand_data, &s);
104
105 s.device_nand = true;
106
107 if (gpmc_t) {
108 err = gpmc_cs_set_timings(gpmc_nand_data->cs, gpmc_t, &s);
109 if (err < 0) {
110 pr_err("omap2-gpmc: Unable to set gpmc timings: %d\n",
111 err);
112 return err;
113 }
114 }
115
116 err = gpmc_cs_program_settings(gpmc_nand_data->cs, &s);
117 if (err < 0)
118 goto out_free_cs;
119
120 err = gpmc_configure(GPMC_CONFIG_WP, 0);
121 if (err < 0)
122 goto out_free_cs;
123
124 gpmc_update_nand_reg(&gpmc_nand_data->reg, gpmc_nand_data->cs);
125
126 if (!gpmc_hwecc_bch_capable(gpmc_nand_data->ecc_opt)) {
127 pr_err("omap2-nand: Unsupported NAND ECC scheme selected\n");
128 err = -EINVAL;
129 goto out_free_cs;
130 }
131
132
133 pdev = platform_device_alloc("omap2-nand", gpmc_nand_data->cs);
134 if (pdev) {
135 err = platform_device_add_resources(pdev, gpmc_nand_res,
136 ARRAY_SIZE(gpmc_nand_res));
137 if (!err)
138 pdev->dev.platform_data = gpmc_nand_data;
139 } else {
140 err = -ENOMEM;
141 }
142 if (err)
143 goto out_free_pdev;
144
145 err = platform_device_add(pdev);
146 if (err) {
147 dev_err(&pdev->dev, "Unable to register NAND device\n");
148 goto out_free_pdev;
149 }
150
151 return 0;
152
153 out_free_pdev:
154 platform_device_put(pdev);
155 out_free_cs:
156 gpmc_cs_free(gpmc_nand_data->cs);
157
158 return err;
159 }
160