projects/linux·blob master · refs

242 lines · 5.7 KiB

1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Versatile OF physmap driver add-on
4 *
5 * Copyright (c) 2016, Linaro Limited
6 * Author: Linus Walleij <[email protected]>
7 */
8#include <linux/export.h>
9#include <linux/io.h>
10#include <linux/of.h>
11#include <linux/of_address.h>
12#include <linux/mtd/map.h>
13#include <linux/mfd/syscon.h>
14#include <linux/platform_device.h>
15#include <linux/regmap.h>
16#include <linux/bitops.h>
17#include "physmap-versatile.h"
18
19static struct regmap *syscon_regmap;
20
21enum versatile_flashprot {
22 INTEGRATOR_AP_FLASHPROT,
23 INTEGRATOR_CP_FLASHPROT,
24 VERSATILE_FLASHPROT,
25 REALVIEW_FLASHPROT,
26};
27
28static const struct of_device_id syscon_match[] = {
29 {
30 .compatible = "arm,integrator-ap-syscon",
31 .data = (void *)INTEGRATOR_AP_FLASHPROT,
32 },
33 {
34 .compatible = "arm,integrator-cp-syscon",
35 .data = (void *)INTEGRATOR_CP_FLASHPROT,
36 },
37 {
38 .compatible = "arm,core-module-versatile",
39 .data = (void *)VERSATILE_FLASHPROT,
40 },
41 {
42 .compatible = "arm,realview-eb-syscon",
43 .data = (void *)REALVIEW_FLASHPROT,
44 },
45 {
46 .compatible = "arm,realview-pb1176-syscon",
47 .data = (void *)REALVIEW_FLASHPROT,
48 },
49 {
50 .compatible = "arm,realview-pb11mp-syscon",
51 .data = (void *)REALVIEW_FLASHPROT,
52 },
53 {
54 .compatible = "arm,realview-pba8-syscon",
55 .data = (void *)REALVIEW_FLASHPROT,
56 },
57 {
58 .compatible = "arm,realview-pbx-syscon",
59 .data = (void *)REALVIEW_FLASHPROT,
60 },
61 {},
62};
63
64/*
65 * Flash protection handling for the Integrator/AP
66 */
67#define INTEGRATOR_SC_CTRLS_OFFSET 0x08
68#define INTEGRATOR_SC_CTRLC_OFFSET 0x0C
69#define INTEGRATOR_SC_CTRL_FLVPPEN BIT(1)
70#define INTEGRATOR_SC_CTRL_FLWP BIT(2)
71
72#define INTEGRATOR_EBI_CSR1_OFFSET 0x04
73/* The manual says bit 2, the code says bit 3, trust the code */
74#define INTEGRATOR_EBI_WRITE_ENABLE BIT(3)
75#define INTEGRATOR_EBI_LOCK_OFFSET 0x20
76#define INTEGRATOR_EBI_LOCK_VAL 0xA05F
77
78static const struct of_device_id ebi_match[] = {
79 { .compatible = "arm,external-bus-interface"},
80 { },
81};
82
83static int ap_flash_init(struct platform_device *pdev)
84{
85 struct device_node *ebi;
86 void __iomem *ebi_base;
87 u32 val;
88 int ret;
89
90 /* Look up the EBI */
91 ebi = of_find_matching_node(NULL, ebi_match);
92 if (!ebi) {
93 return -ENODEV;
94 }
95 ebi_base = of_iomap(ebi, 0);
96 of_node_put(ebi);
97 if (!ebi_base)
98 return -ENODEV;
99
100 /* Clear VPP and write protection bits */
101 ret = regmap_write(syscon_regmap,
102 INTEGRATOR_SC_CTRLC_OFFSET,
103 INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP);
104 if (ret)
105 dev_err(&pdev->dev, "error clearing Integrator VPP/WP\n");
106
107 /* Unlock the EBI */
108 writel(INTEGRATOR_EBI_LOCK_VAL, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET);
109
110 /* Enable write cycles on the EBI, CSR1 (flash) */
111 val = readl(ebi_base + INTEGRATOR_EBI_CSR1_OFFSET);
112 val |= INTEGRATOR_EBI_WRITE_ENABLE;
113 writel(val, ebi_base + INTEGRATOR_EBI_CSR1_OFFSET);
114
115 /* Lock the EBI again */
116 writel(0, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET);
117 iounmap(ebi_base);
118
119 return 0;
120}
121
122static void ap_flash_set_vpp(struct map_info *map, int on)
123{
124 int ret;
125
126 if (on) {
127 ret = regmap_write(syscon_regmap,
128 INTEGRATOR_SC_CTRLS_OFFSET,
129 INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP);
130 if (ret)
131 pr_err("error enabling AP VPP\n");
132 } else {
133 ret = regmap_write(syscon_regmap,
134 INTEGRATOR_SC_CTRLC_OFFSET,
135 INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP);
136 if (ret)
137 pr_err("error disabling AP VPP\n");
138 }
139}
140
141/*
142 * Flash protection handling for the Integrator/CP
143 */
144
145#define INTCP_FLASHPROG_OFFSET 0x04
146#define CINTEGRATOR_FLVPPEN BIT(0)
147#define CINTEGRATOR_FLWREN BIT(1)
148#define CINTEGRATOR_FLMASK BIT(0)|BIT(1)
149
150static void cp_flash_set_vpp(struct map_info *map, int on)
151{
152 int ret;
153
154 if (on) {
155 ret = regmap_update_bits(syscon_regmap,
156 INTCP_FLASHPROG_OFFSET,
157 CINTEGRATOR_FLMASK,
158 CINTEGRATOR_FLVPPEN | CINTEGRATOR_FLWREN);
159 if (ret)
160 pr_err("error setting CP VPP\n");
161 } else {
162 ret = regmap_update_bits(syscon_regmap,
163 INTCP_FLASHPROG_OFFSET,
164 CINTEGRATOR_FLMASK,
165 0);
166 if (ret)
167 pr_err("error setting CP VPP\n");
168 }
169}
170
171/*
172 * Flash protection handling for the Versatiles and RealViews
173 */
174
175#define VERSATILE_SYS_FLASH_OFFSET 0x4C
176
177static void versatile_flash_set_vpp(struct map_info *map, int on)
178{
179 int ret;
180
181 ret = regmap_update_bits(syscon_regmap, VERSATILE_SYS_FLASH_OFFSET,
182 0x01, !!on);
183 if (ret)
184 pr_err("error setting Versatile VPP\n");
185}
186
187int of_flash_probe_versatile(struct platform_device *pdev,
188 struct device_node *np,
189 struct map_info *map)
190{
191 struct device_node *sysnp;
192 const struct of_device_id *devid;
193 struct regmap *rmap;
194 static enum versatile_flashprot versatile_flashprot;
195 int ret;
196
197 /* Not all flash chips use this protection line */
198 if (!of_device_is_compatible(np, "arm,versatile-flash"))
199 return 0;
200
201 /* For first chip probed, look up the syscon regmap */
202 if (!syscon_regmap) {
203 sysnp = of_find_matching_node_and_match(NULL,
204 syscon_match,
205 &devid);
206 if (!sysnp)
207 return -ENODEV;
208
209 versatile_flashprot = (uintptr_t)devid->data;
210 rmap = syscon_node_to_regmap(sysnp);
211 of_node_put(sysnp);
212 if (IS_ERR(rmap))
213 return PTR_ERR(rmap);
214
215 syscon_regmap = rmap;
216 }
217
218 switch (versatile_flashprot) {
219 case INTEGRATOR_AP_FLASHPROT:
220 ret = ap_flash_init(pdev);
221 if (ret)
222 return ret;
223 map->set_vpp = ap_flash_set_vpp;
224 dev_info(&pdev->dev, "Integrator/AP flash protection\n");
225 break;
226 case INTEGRATOR_CP_FLASHPROT:
227 map->set_vpp = cp_flash_set_vpp;
228 dev_info(&pdev->dev, "Integrator/CP flash protection\n");
229 break;
230 case VERSATILE_FLASHPROT:
231 case REALVIEW_FLASHPROT:
232 map->set_vpp = versatile_flash_set_vpp;
233 dev_info(&pdev->dev, "versatile/realview flash protection\n");
234 break;
235 default:
236 dev_info(&pdev->dev, "device marked as Versatile flash "
237 "but no system controller was found\n");
238 break;
239 }
240
241 return 0;
242}