1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
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].
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
14 #define LOG_CATEGORY UCLASS_MISC
20 #include <dm/device_compat.h>
22 #include <linux/bitfield.h>
23 #include <power/regulator.h>
25 DECLARE_GLOBAL_DATA_PTR;
28 #define SFP_SVHESR 0x24
29 #define SFP_SFPCR 0x28
31 #define SFP_START 0x200
33 #define SFP_SIZE (SFP_END - SFP_START + 4)
35 #define SFP_INGR_ERR BIT(8)
36 #define SFP_INGR_INST GENMASK(7, 0)
38 #define SFP_INGR_READFB 0x01
39 #define SFP_INGR_PROGFB 0x02
41 #define SFP_SFPCR_PPW GENMASK(15, 0)
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
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.
65 struct udevice *supply;
66 bool programmed, dirty;
69 static u32 ls2_sfp_readl(struct ls2_sfp_priv *priv, ulong off)
71 u32 val = be32_to_cpu(readl(priv->base + off));
73 log_debug("%08x = readl(%p)\n", val, priv->base + off);
77 static void ls2_sfp_writel(struct ls2_sfp_priv *priv, ulong val, ulong off)
79 log_debug("writel(%08lx, %p)\n", val, priv->base + off);
80 writel(cpu_to_be32(val), priv->base + off);
83 static bool ls2_sfp_validate(struct udevice *dev, int offset, int size)
85 if (offset < 0 || size < 0) {
86 dev_notice(dev, "size and offset must be positive\n");
90 if (offset & 3 || size & 3) {
91 dev_notice(dev, "size and offset must be multiples of 4\n");
95 if (offset + size > SFP_SIZE) {
96 dev_notice(dev, "size + offset must be <= %#x\n", SFP_SIZE);
103 static int ls2_sfp_read(struct udevice *dev, int offset, void *buf_bytes,
107 struct ls2_sfp_priv *priv = dev_get_priv(dev);
108 u32 *buf = buf_bytes;
110 if (!ls2_sfp_validate(dev, offset, size))
113 for (i = 0; i < size; i += 4)
114 buf[i >> 2] = ls2_sfp_readl(priv, SFP_START + offset + i);
119 static int ls2_sfp_write(struct udevice *dev, int offset,
120 const void *buf_bytes, int size)
123 struct ls2_sfp_priv *priv = dev_get_priv(dev);
124 const u32 *buf = buf_bytes;
126 if (!ls2_sfp_validate(dev, offset, size))
129 for (i = 0; i < size; i += 4)
130 ls2_sfp_writel(priv, buf[i >> 2], SFP_START + offset + i);
136 static int ls2_sfp_check_secret(struct udevice *dev)
138 struct ls2_sfp_priv *priv = dev_get_priv(dev);
139 u32 svhesr = ls2_sfp_readl(priv, SFP_SVHESR);
142 dev_warn(dev, "secret value hamming error not zero: %08x\n",
149 static int ls2_sfp_transaction(struct ls2_sfp_priv *priv, ulong inst)
153 ls2_sfp_writel(priv, inst, SFP_INGR);
156 ingr = ls2_sfp_readl(priv, SFP_INGR);
157 } while (FIELD_GET(SFP_INGR_INST, ingr));
159 return FIELD_GET(SFP_INGR_ERR, ingr) ? -EIO : 0;
162 static int ls2_sfp_ioctl(struct udevice *dev, unsigned long request, void *buf)
165 struct ls2_sfp_priv *priv = dev_get_priv(dev);
168 case LS2_SFP_IOCTL_READ:
170 dev_dbg(dev, "ignoring read request, since fuses are not dirty\n");
174 ret = ls2_sfp_transaction(priv, SFP_INGR_READFB);
176 dev_err(dev, "error reading fuses\n");
180 ls2_sfp_check_secret(dev);
183 case LS2_SFP_IOCTL_PROG:
184 if (priv->programmed) {
185 dev_warn(dev, "fuses already programmed\n");
189 ret = ls2_sfp_check_secret(dev);
194 ret = regulator_set_enable(priv->supply, true);
199 ret = ls2_sfp_transaction(priv, SFP_INGR_PROGFB);
200 priv->programmed = true;
202 regulator_set_enable(priv->supply, false);
205 dev_err(dev, "error programming fuses\n");
208 dev_dbg(dev, "unknown ioctl %lu\n", request);
213 static const struct misc_ops ls2_sfp_ops = {
214 .read = ls2_sfp_read,
215 .write = ls2_sfp_write,
216 .ioctl = ls2_sfp_ioctl,
219 static int ls2_sfp_probe(struct udevice *dev)
223 struct ls2_sfp_priv *priv = dev_get_priv(dev);
226 priv->base = dev_read_addr_ptr(dev);
228 dev_dbg(dev, "could not read register base\n");
232 ret = device_get_supply_regulator(dev, "ta-sfp-prog-supply", &priv->supply);
233 if (ret && ret != -ENODEV && ret != -ENOSYS) {
234 dev_dbg(dev, "problem getting supply (err %d)\n", ret);
238 ret = clk_get_by_name(dev, "sfp", &clk);
239 if (ret == -ENOSYS) {
240 rate = gd->bus_clk / 4;
242 dev_dbg(dev, "could not get clock (err %d)\n", ret);
245 ret = clk_enable(&clk);
247 dev_dbg(dev, "could not enable clock (err %d)\n", ret);
251 rate = clk_get_rate(&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",
261 /* sfp clock in MHz * 12 */
262 ls2_sfp_writel(priv, FIELD_PREP(SFP_SFPCR_PPW, rate * 12 / 1000000),
265 ls2_sfp_check_secret(dev);
269 static const struct udevice_id ls2_sfp_ids[] = {
270 { .compatible = "fsl,ls1021a-sfp" },
274 U_BOOT_DRIVER(ls2_sfp) = {
277 .of_match = ls2_sfp_ids,
278 .probe = ls2_sfp_probe,
280 .priv_auto = sizeof(struct ls2_sfp_priv),
283 static int ls2_sfp_device(struct udevice **dev)
285 int ret = uclass_get_device_by_driver(UCLASS_MISC,
286 DM_DRIVER_GET(ls2_sfp), dev);
289 log_debug("device not found (err %d)\n", ret);
293 int fuse_read(u32 bank, u32 word, u32 *val)
298 ret = ls2_sfp_device(&dev);
302 ret = misc_ioctl(dev, LS2_SFP_IOCTL_READ, NULL);
306 ret = misc_read(dev, word << 2, val, sizeof(*val));
307 return ret < 0 ? ret : 0;
310 int fuse_sense(u32 bank, u32 word, u32 *val)
315 ret = ls2_sfp_device(&dev);
319 ret = misc_read(dev, word << 2, val, sizeof(*val));
320 return ret < 0 ? ret : 0;
323 int fuse_prog(u32 bank, u32 word, u32 val)
328 ret = ls2_sfp_device(&dev);
332 ret = misc_write(dev, word << 2, &val, sizeof(val));
336 return misc_ioctl(dev, LS2_SFP_IOCTL_PROG, NULL);
339 int fuse_override(u32 bank, u32 word, u32 val)
344 ret = ls2_sfp_device(&dev);
348 ret = misc_write(dev, word << 2, &val, sizeof(val));
349 return ret < 0 ? ret : 0;