blob: dd104962c28209337bc53a512b4f9b2ba67a4358 [file] [log] [blame]
Sean Anderson2645bc02022-04-22 14:34:18 -04001// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
4 *
5 * This driver supports the Security Fuse Processor device found on some
6 * Layerscape processors. At the moment, we only support a few processors.
7 * This driver was written with reference to the Layerscape SDK User
8 * Guide [1] and the ATF SFP driver [2].
9 *
10 * [1] https://docs.nxp.com/bundle/GUID-487B2E69-BB19-42CB-AC38-7EF18C0FE3AE/page/GUID-27FC40AD-3321-4A82-B29E-7BB49EE94F23.html
11 * [2] https://source.codeaurora.org/external/qoriq/qoriq-components/atf/tree/drivers/nxp/sfp?h=github.com/master
12 */
13
14#define LOG_CATEGORY UCLASS_MISC
15#include <common.h>
16#include <clk.h>
17#include <fuse.h>
18#include <misc.h>
19#include <asm/io.h>
20#include <dm/device_compat.h>
21#include <dm/read.h>
22#include <linux/bitfield.h>
23#include <power/regulator.h>
24
25DECLARE_GLOBAL_DATA_PTR;
26
27#define SFP_INGR 0x20
28#define SFP_SVHESR 0x24
29#define SFP_SFPCR 0x28
30
31#define SFP_START 0x200
32#define SFP_END 0x284
33#define SFP_SIZE (SFP_END - SFP_START + 4)
34
35#define SFP_INGR_ERR BIT(8)
36#define SFP_INGR_INST GENMASK(7, 0)
37
38#define SFP_INGR_READFB 0x01
39#define SFP_INGR_PROGFB 0x02
40
41#define SFP_SFPCR_PPW GENMASK(15, 0)
42
43enum ls2_sfp_ioctl {
44 LS2_SFP_IOCTL_READ,
45 LS2_SFP_IOCTL_PROG,
46};
47
48/**
49 * struct ls2_sfp_priv - private data for LS2 SFP
50 * @base: Base address of SFP
51 * @supply: The (optional) supply for TA_PROG_SFP
52 * @programmed: Whether we've already programmed the fuses since the last
53 * reset. The SFP has a *very* limited amount of programming
54 * cycles (two to six, depending on the model), so we try and
55 * prevent accidentally performing additional programming
56 * cycles.
57 * @dirty: Whether the mirror registers have been written to (overridden)
58 * since we've last read the fuses (either as part of the reset
59 * process or using a READFB instruction). There is a much larger,
60 * but still finite, limit on the number of SFP read cycles (around
61 * 300,000), so we try and minimize reads as well.
62 */
63struct ls2_sfp_priv {
64 void __iomem *base;
65 struct udevice *supply;
66 bool programmed, dirty;
67};
68
69static u32 ls2_sfp_readl(struct ls2_sfp_priv *priv, ulong off)
70{
71 u32 val = be32_to_cpu(readl(priv->base + off));
72
73 log_debug("%08x = readl(%p)\n", val, priv->base + off);
74 return val;
75}
76
77static void ls2_sfp_writel(struct ls2_sfp_priv *priv, ulong val, ulong off)
78{
79 log_debug("writel(%08lx, %p)\n", val, priv->base + off);
80 writel(cpu_to_be32(val), priv->base + off);
81}
82
83static bool ls2_sfp_validate(struct udevice *dev, int offset, int size)
84{
85 if (offset < 0 || size < 0) {
86 dev_notice(dev, "size and offset must be positive\n");
87 return false;
88 }
89
90 if (offset & 3 || size & 3) {
91 dev_notice(dev, "size and offset must be multiples of 4\n");
92 return false;
93 }
94
95 if (offset + size > SFP_SIZE) {
96 dev_notice(dev, "size + offset must be <= %#x\n", SFP_SIZE);
97 return false;
98 }
99
100 return true;
101}
102
103static int ls2_sfp_read(struct udevice *dev, int offset, void *buf_bytes,
104 int size)
105{
106 int i;
107 struct ls2_sfp_priv *priv = dev_get_priv(dev);
108 u32 *buf = buf_bytes;
109
110 if (!ls2_sfp_validate(dev, offset, size))
111 return -EINVAL;
112
113 for (i = 0; i < size; i += 4)
114 buf[i >> 2] = ls2_sfp_readl(priv, SFP_START + offset + i);
115
116 return size;
117}
118
119static int ls2_sfp_write(struct udevice *dev, int offset,
120 const void *buf_bytes, int size)
121{
122 int i;
123 struct ls2_sfp_priv *priv = dev_get_priv(dev);
124 const u32 *buf = buf_bytes;
125
126 if (!ls2_sfp_validate(dev, offset, size))
127 return -EINVAL;
128
129 for (i = 0; i < size; i += 4)
130 ls2_sfp_writel(priv, buf[i >> 2], SFP_START + offset + i);
131
132 priv->dirty = true;
133 return size;
134}
135
136static int ls2_sfp_check_secret(struct udevice *dev)
137{
138 struct ls2_sfp_priv *priv = dev_get_priv(dev);
139 u32 svhesr = ls2_sfp_readl(priv, SFP_SVHESR);
140
141 if (svhesr) {
142 dev_warn(dev, "secret value hamming error not zero: %08x\n",
143 svhesr);
144 return -EIO;
145 }
146 return 0;
147}
148
149static int ls2_sfp_transaction(struct ls2_sfp_priv *priv, ulong inst)
150{
151 u32 ingr;
152
153 ls2_sfp_writel(priv, inst, SFP_INGR);
154
155 do {
156 ingr = ls2_sfp_readl(priv, SFP_INGR);
157 } while (FIELD_GET(SFP_INGR_INST, ingr));
158
159 return FIELD_GET(SFP_INGR_ERR, ingr) ? -EIO : 0;
160}
161
162static int ls2_sfp_ioctl(struct udevice *dev, unsigned long request, void *buf)
163{
164 int ret;
165 struct ls2_sfp_priv *priv = dev_get_priv(dev);
166
167 switch (request) {
168 case LS2_SFP_IOCTL_READ:
169 if (!priv->dirty) {
170 dev_dbg(dev, "ignoring read request, since fuses are not dirty\n");
171 return 0;
172 }
173
174 ret = ls2_sfp_transaction(priv, SFP_INGR_READFB);
175 if (ret) {
176 dev_err(dev, "error reading fuses\n");
177 return ret;
178 }
179
180 ls2_sfp_check_secret(dev);
181 priv->dirty = false;
182 return 0;
183 case LS2_SFP_IOCTL_PROG:
184 if (priv->programmed) {
185 dev_warn(dev, "fuses already programmed\n");
186 return -EPERM;
187 }
188
189 ret = ls2_sfp_check_secret(dev);
190 if (ret)
191 return ret;
192
193 if (priv->supply) {
194 ret = regulator_set_enable(priv->supply, true);
195 if (ret)
196 return ret;
197 }
198
199 ret = ls2_sfp_transaction(priv, SFP_INGR_PROGFB);
200 priv->programmed = true;
201 if (priv->supply)
202 regulator_set_enable(priv->supply, false);
203
204 if (ret)
205 dev_err(dev, "error programming fuses\n");
206 return ret;
207 default:
208 dev_dbg(dev, "unknown ioctl %lu\n", request);
209 return -EINVAL;
210 }
211}
212
213static const struct misc_ops ls2_sfp_ops = {
214 .read = ls2_sfp_read,
215 .write = ls2_sfp_write,
216 .ioctl = ls2_sfp_ioctl,
217};
218
219static int ls2_sfp_probe(struct udevice *dev)
220{
221 int ret;
222 struct clk clk;
223 struct ls2_sfp_priv *priv = dev_get_priv(dev);
224 ulong rate;
225
226 priv->base = dev_read_addr_ptr(dev);
227 if (!priv->base) {
228 dev_dbg(dev, "could not read register base\n");
229 return -EINVAL;
230 }
231
232 ret = device_get_supply_regulator(dev, "ta-sfp-prog", &priv->supply);
233 if (ret && ret != -ENODEV && ret != -ENOSYS) {
234 dev_dbg(dev, "problem getting supply (err %d)\n", ret);
235 return ret;
236 }
237
238 ret = clk_get_by_name(dev, "sfp", &clk);
239 if (ret == -ENOSYS) {
240 rate = gd->bus_clk / 4;
241 } else if (ret) {
242 dev_dbg(dev, "could not get clock (err %d)\n", ret);
243 return ret;
244 } else {
245 ret = clk_enable(&clk);
246 if (ret) {
247 dev_dbg(dev, "could not enable clock (err %d)\n", ret);
248 return ret;
249 }
250
251 rate = clk_get_rate(&clk);
252 clk_free(&clk);
253 if (!rate || IS_ERR_VALUE(rate)) {
254 ret = rate ? rate : -ENOENT;
255 dev_dbg(dev, "could not get clock rate (err %d)\n",
256 ret);
257 return ret;
258 }
259 }
260
261 /* sfp clock in MHz * 12 */
262 ls2_sfp_writel(priv, FIELD_PREP(SFP_SFPCR_PPW, rate * 12 / 1000000),
263 SFP_SFPCR);
264
265 ls2_sfp_check_secret(dev);
266 return 0;
267}
268
269static const struct udevice_id ls2_sfp_ids[] = {
270 { .compatible = "fsl,ls1021a-sfp" },
271 { }
272};
273
274U_BOOT_DRIVER(ls2_sfp) = {
275 .name = "ls2_sfp",
276 .id = UCLASS_MISC,
277 .of_match = ls2_sfp_ids,
278 .probe = ls2_sfp_probe,
279 .ops = &ls2_sfp_ops,
280 .priv_auto = sizeof(struct ls2_sfp_priv),
281};
282
283static int ls2_sfp_device(struct udevice **dev)
284{
285 int ret = uclass_get_device_by_driver(UCLASS_MISC,
286 DM_DRIVER_GET(ls2_sfp), dev);
287
288 if (ret)
289 log_debug("device not found (err %d)\n", ret);
290 return ret;
291}
292
293int fuse_read(u32 bank, u32 word, u32 *val)
294{
295 int ret;
296 struct udevice *dev;
297
298 ret = ls2_sfp_device(&dev);
299 if (ret)
300 return ret;
301
302 ret = misc_ioctl(dev, LS2_SFP_IOCTL_READ, NULL);
303 if (ret)
304 return ret;
305
306 ret = misc_read(dev, word << 2, val, sizeof(*val));
307 return ret < 0 ? ret : 0;
308}
309
310int fuse_sense(u32 bank, u32 word, u32 *val)
311{
312 int ret;
313 struct udevice *dev;
314
315 ret = ls2_sfp_device(&dev);
316 if (ret)
317 return ret;
318
319 ret = misc_read(dev, word << 2, val, sizeof(*val));
320 return ret < 0 ? ret : 0;
321}
322
323int fuse_prog(u32 bank, u32 word, u32 val)
324{
325 int ret;
326 struct udevice *dev;
327
328 ret = ls2_sfp_device(&dev);
329 if (ret)
330 return ret;
331
332 ret = misc_write(dev, word << 2, &val, sizeof(val));
333 if (ret < 0)
334 return ret;
335
336 return misc_ioctl(dev, LS2_SFP_IOCTL_PROG, NULL);
337}
338
339int fuse_override(u32 bank, u32 word, u32 val)
340{
341 int ret;
342 struct udevice *dev;
343
344 ret = ls2_sfp_device(&dev);
345 if (ret)
346 return ret;
347
348 ret = misc_write(dev, word << 2, &val, sizeof(val));
349 return ret < 0 ? ret : 0;
350}