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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001// SPDX-License-Identifier: GPL-2.0
Linus Walleij56ff3372017-01-28 22:50:48 +01002/*
3 * Cortina Systems Gemini OF physmap add-on
4 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
5 *
6 * This SoC has an elaborate flash control register, so we need to
7 * detect and set it up when booting on this platform.
8 */
9#include <linux/export.h>
10#include <linux/of.h>
11#include <linux/of_device.h>
12#include <linux/mtd/map.h>
Linus Walleij9d3b5082018-11-27 21:53:58 +010013#include <linux/mtd/xip.h>
Linus Walleij56ff3372017-01-28 22:50:48 +010014#include <linux/mfd/syscon.h>
15#include <linux/regmap.h>
16#include <linux/bitops.h>
Linus Walleij9d3b5082018-11-27 21:53:58 +010017#include <linux/pinctrl/consumer.h>
Boris Brezillon6ca15cf2018-10-19 09:49:05 +020018#include "physmap-gemini.h"
Linus Walleij56ff3372017-01-28 22:50:48 +010019
20/*
21 * The Flash-relevant parts of the global status register
22 * These would also be relevant for a NAND driver.
23 */
24#define GLOBAL_STATUS 0x04
25#define FLASH_TYPE_MASK (0x3 << 24)
26#define FLASH_TYPE_NAND_2K (0x3 << 24)
27#define FLASH_TYPE_NAND_512 (0x2 << 24)
28#define FLASH_TYPE_PARALLEL (0x1 << 24)
29#define FLASH_TYPE_SERIAL (0x0 << 24)
30/* if parallel */
31#define FLASH_WIDTH_16BIT (1 << 23) /* else 8 bit */
32/* if serial */
33#define FLASH_ATMEL (1 << 23) /* else STM */
34
35#define FLASH_SIZE_MASK (0x3 << 21)
36#define NAND_256M (0x3 << 21) /* and more */
37#define NAND_128M (0x2 << 21)
38#define NAND_64M (0x1 << 21)
39#define NAND_32M (0x0 << 21)
40#define ATMEL_16M (0x3 << 21) /* and more */
41#define ATMEL_8M (0x2 << 21)
42#define ATMEL_4M_2M (0x1 << 21)
43#define ATMEL_1M (0x0 << 21) /* and less */
44#define STM_32M (1 << 22) /* and more */
45#define STM_16M (0 << 22) /* and less */
46
47#define FLASH_PARALLEL_HIGH_PIN_CNT (1 << 20) /* else low pin cnt */
48
Linus Walleij9d3b5082018-11-27 21:53:58 +010049static const struct of_device_id syscon_match[] = {
50 { .compatible = "cortina,gemini-syscon" },
51 { },
52};
53
54struct gemini_flash {
55 struct device *dev;
56 struct pinctrl *p;
57 struct pinctrl_state *enabled_state;
58 struct pinctrl_state *disabled_state;
59};
60
61/* Static local state */
62static struct gemini_flash *gf;
63
64static void gemini_flash_enable_pins(void)
65{
66 int ret;
67
68 if (IS_ERR(gf->enabled_state))
69 return;
70 ret = pinctrl_select_state(gf->p, gf->enabled_state);
71 if (ret)
72 dev_err(gf->dev, "failed to enable pins\n");
73}
74
75static void gemini_flash_disable_pins(void)
76{
77 int ret;
78
79 if (IS_ERR(gf->disabled_state))
80 return;
81 ret = pinctrl_select_state(gf->p, gf->disabled_state);
82 if (ret)
83 dev_err(gf->dev, "failed to disable pins\n");
84}
85
86static map_word __xipram gemini_flash_map_read(struct map_info *map,
87 unsigned long ofs)
88{
89 map_word __xipram ret;
90
91 gemini_flash_enable_pins();
92 ret = inline_map_read(map, ofs);
93 gemini_flash_disable_pins();
94
95 return ret;
96}
97
98static void __xipram gemini_flash_map_write(struct map_info *map,
99 const map_word datum,
100 unsigned long ofs)
101{
102 gemini_flash_enable_pins();
103 inline_map_write(map, datum, ofs);
104 gemini_flash_disable_pins();
105}
106
107static void __xipram gemini_flash_map_copy_from(struct map_info *map,
108 void *to, unsigned long from,
109 ssize_t len)
110{
111 gemini_flash_enable_pins();
112 inline_map_copy_from(map, to, from, len);
113 gemini_flash_disable_pins();
114}
115
116static void __xipram gemini_flash_map_copy_to(struct map_info *map,
117 unsigned long to,
118 const void *from, ssize_t len)
119{
120 gemini_flash_enable_pins();
121 inline_map_copy_to(map, to, from, len);
122 gemini_flash_disable_pins();
123}
124
Linus Walleij56ff3372017-01-28 22:50:48 +0100125int of_flash_probe_gemini(struct platform_device *pdev,
126 struct device_node *np,
127 struct map_info *map)
128{
Julia Lawall6c51a522017-05-04 22:10:47 +0200129 struct regmap *rmap;
Linus Walleij56ff3372017-01-28 22:50:48 +0100130 struct device *dev = &pdev->dev;
131 u32 val;
132 int ret;
133
134 /* Multiplatform guard */
135 if (!of_device_is_compatible(np, "cortina,gemini-flash"))
136 return 0;
137
Linus Walleij9d3b5082018-11-27 21:53:58 +0100138 gf = devm_kzalloc(dev, sizeof(*gf), GFP_KERNEL);
139 if (!gf)
140 return -ENOMEM;
141 gf->dev = dev;
142
Linus Walleij56ff3372017-01-28 22:50:48 +0100143 rmap = syscon_regmap_lookup_by_phandle(np, "syscon");
144 if (IS_ERR(rmap)) {
145 dev_err(dev, "no syscon\n");
146 return PTR_ERR(rmap);
147 }
148
149 ret = regmap_read(rmap, GLOBAL_STATUS, &val);
150 if (ret) {
151 dev_err(dev, "failed to read global status register\n");
152 return -ENODEV;
153 }
154 dev_dbg(dev, "global status reg: %08x\n", val);
155
156 /*
157 * It would be contradictory if a physmap flash was NOT parallel.
158 */
159 if ((val & FLASH_TYPE_MASK) != FLASH_TYPE_PARALLEL) {
160 dev_err(dev, "flash is not parallel\n");
161 return -ENODEV;
162 }
163
164 /*
165 * Complain if DT data and hardware definition is different.
166 */
167 if (val & FLASH_WIDTH_16BIT) {
168 if (map->bankwidth != 2)
169 dev_warn(dev, "flash hardware say flash is 16 bit wide but DT says it is %d bits wide\n",
170 map->bankwidth * 8);
171 } else {
172 if (map->bankwidth != 1)
173 dev_warn(dev, "flash hardware say flash is 8 bit wide but DT says it is %d bits wide\n",
174 map->bankwidth * 8);
175 }
176
Linus Walleij9d3b5082018-11-27 21:53:58 +0100177 gf->p = devm_pinctrl_get(dev);
178 if (IS_ERR(gf->p)) {
179 dev_err(dev, "no pinctrl handle\n");
180 ret = PTR_ERR(gf->p);
181 return ret;
182 }
183
184 gf->enabled_state = pinctrl_lookup_state(gf->p, "enabled");
185 if (IS_ERR(gf->enabled_state))
186 dev_err(dev, "no enabled pin control state\n");
187
188 gf->disabled_state = pinctrl_lookup_state(gf->p, "disabled");
189 if (IS_ERR(gf->enabled_state)) {
190 dev_err(dev, "no disabled pin control state\n");
191 } else {
192 ret = pinctrl_select_state(gf->p, gf->disabled_state);
193 if (ret)
194 dev_err(gf->dev, "failed to disable pins\n");
195 }
196
197 map->read = gemini_flash_map_read;
198 map->write = gemini_flash_map_write;
199 map->copy_from = gemini_flash_map_copy_from;
200 map->copy_to = gemini_flash_map_copy_to;
201
202 dev_info(dev, "initialized Gemini-specific physmap control\n");
Linus Walleij56ff3372017-01-28 22:50:48 +0100203
204 return 0;
205}