1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
4 */
5
6 #include <linux/clk.h>
7 #include <linux/device.h>
8 #include <linux/io.h>
9 #include <linux/iopoll.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/mod_devicetable.h>
13 #include <linux/nvmem-provider.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_domain.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/property.h>
18 #include <linux/regulator/consumer.h>
19
20 /* Blow timer clock frequency in Mhz */
21 #define QFPROM_BLOW_TIMER_OFFSET 0x03c
22
23 /* Amount of time required to hold charge to blow fuse in micro-seconds */
24 #define QFPROM_FUSE_BLOW_POLL_US 100
25 #define QFPROM_FUSE_BLOW_TIMEOUT_US 10000
26
27 #define QFPROM_BLOW_STATUS_OFFSET 0x048
28 #define QFPROM_BLOW_STATUS_BUSY 0x1
29 #define QFPROM_BLOW_STATUS_READY 0x0
30
31 #define QFPROM_ACCEL_OFFSET 0x044
32
33 #define QFPROM_VERSION_OFFSET 0x0
34 #define QFPROM_MAJOR_VERSION_SHIFT 28
35 #define QFPROM_MAJOR_VERSION_MASK GENMASK(31, QFPROM_MAJOR_VERSION_SHIFT)
36 #define QFPROM_MINOR_VERSION_SHIFT 16
37 #define QFPROM_MINOR_VERSION_MASK GENMASK(27, QFPROM_MINOR_VERSION_SHIFT)
38
39 static bool read_raw_data;
40 module_param(read_raw_data, bool, 0644);
41 MODULE_PARM_DESC(read_raw_data, "Read raw instead of corrected data");
42
43 /**
44 * struct qfprom_soc_data - config that varies from SoC to SoC.
45 *
46 * @accel_value: Should contain qfprom accel value.
47 * @qfprom_blow_timer_value: The timer value of qfprom when doing efuse blow.
48 * @qfprom_blow_set_freq: The frequency required to set when we start the
49 * fuse blowing.
50 * @qfprom_blow_uV: LDO voltage to be set when doing efuse blow
51 */
52 struct qfprom_soc_data {
53 u32 accel_value;
54 u32 qfprom_blow_timer_value;
55 u32 qfprom_blow_set_freq;
56 int qfprom_blow_uV;
57 };
58
59 /**
60 * struct qfprom_priv - structure holding qfprom attributes
61 *
62 * @qfpraw: iomapped memory space for qfprom-efuse raw address space.
63 * @qfpconf: iomapped memory space for qfprom-efuse configuration address
64 * space.
65 * @qfpcorrected: iomapped memory space for qfprom corrected address space.
66 * @qfpsecurity: iomapped memory space for qfprom security control space.
67 * @dev: qfprom device structure.
68 * @secclk: Clock supply.
69 * @vcc: Regulator supply.
70 * @soc_data: Data that for things that varies from SoC to SoC.
71 */
72 struct qfprom_priv {
73 void __iomem *qfpraw;
74 void __iomem *qfpconf;
75 void __iomem *qfpcorrected;
76 void __iomem *qfpsecurity;
77 struct device *dev;
78 struct clk *secclk;
79 struct regulator *vcc;
80 const struct qfprom_soc_data *soc_data;
81 };
82
83 /**
84 * struct qfprom_touched_values - saved values to restore after blowing
85 *
86 * @clk_rate: The rate the clock was at before blowing.
87 * @accel_val: The value of the accel reg before blowing.
88 * @timer_val: The value of the timer before blowing.
89 */
90 struct qfprom_touched_values {
91 unsigned long clk_rate;
92 u32 accel_val;
93 u32 timer_val;
94 };
95
96 /**
97 * struct qfprom_soc_compatible_data - Data matched against the SoC
98 * compatible string.
99 *
100 * @keepout: Array of keepout regions for this SoC.
101 * @nkeepout: Number of elements in the keepout array.
102 */
103 struct qfprom_soc_compatible_data {
104 const struct nvmem_keepout *keepout;
105 unsigned int nkeepout;
106 };
107
108 static const struct nvmem_keepout sc7180_qfprom_keepout[] = {
109 {.start = 0x128, .end = 0x148},
110 {.start = 0x220, .end = 0x228}
111 };
112
113 static const struct qfprom_soc_compatible_data sc7180_qfprom = {
114 .keepout = sc7180_qfprom_keepout,
115 .nkeepout = ARRAY_SIZE(sc7180_qfprom_keepout)
116 };
117
118 static const struct nvmem_keepout sc7280_qfprom_keepout[] = {
119 {.start = 0x128, .end = 0x148},
120 {.start = 0x238, .end = 0x248}
121 };
122
123 static const struct qfprom_soc_compatible_data sc7280_qfprom = {
124 .keepout = sc7280_qfprom_keepout,
125 .nkeepout = ARRAY_SIZE(sc7280_qfprom_keepout)
126 };
127
128 /**
129 * qfprom_disable_fuse_blowing() - Undo enabling of fuse blowing.
130 * @priv: Our driver data.
131 * @old: The data that was stashed from before fuse blowing.
132 *
133 * Resets the value of the blow timer, accel register and the clock
134 * and voltage settings.
135 *
136 * Prints messages if there are errors but doesn't return an error code
137 * since there's not much we can do upon failure.
138 */
qfprom_disable_fuse_blowing(const struct qfprom_priv * priv,const struct qfprom_touched_values * old)139 static void qfprom_disable_fuse_blowing(const struct qfprom_priv *priv,
140 const struct qfprom_touched_values *old)
141 {
142 int ret;
143
144 writel(old->timer_val, priv->qfpconf + QFPROM_BLOW_TIMER_OFFSET);
145 writel(old->accel_val, priv->qfpconf + QFPROM_ACCEL_OFFSET);
146
147 dev_pm_genpd_set_performance_state(priv->dev, 0);
148 pm_runtime_put(priv->dev);
149
150 /*
151 * This may be a shared rail and may be able to run at a lower rate
152 * when we're not blowing fuses. At the moment, the regulator framework
153 * applies voltage constraints even on disabled rails, so remove our
154 * constraints and allow the rail to be adjusted by other users.
155 */
156 ret = regulator_set_voltage(priv->vcc, 0, INT_MAX);
157 if (ret)
158 dev_warn(priv->dev, "Failed to set 0 voltage (ignoring)\n");
159
160 ret = regulator_disable(priv->vcc);
161 if (ret)
162 dev_warn(priv->dev, "Failed to disable regulator (ignoring)\n");
163
164 ret = clk_set_rate(priv->secclk, old->clk_rate);
165 if (ret)
166 dev_warn(priv->dev,
167 "Failed to set clock rate for disable (ignoring)\n");
168
169 clk_disable_unprepare(priv->secclk);
170 }
171
172 /**
173 * qfprom_enable_fuse_blowing() - Enable fuse blowing.
174 * @priv: Our driver data.
175 * @old: We'll stash stuff here to use when disabling.
176 *
177 * Sets the value of the blow timer, accel register and the clock
178 * and voltage settings.
179 *
180 * Prints messages if there are errors so caller doesn't need to.
181 *
182 * Return: 0 or -err.
183 */
qfprom_enable_fuse_blowing(const struct qfprom_priv * priv,struct qfprom_touched_values * old)184 static int qfprom_enable_fuse_blowing(const struct qfprom_priv *priv,
185 struct qfprom_touched_values *old)
186 {
187 int ret;
188 int qfprom_blow_uV = priv->soc_data->qfprom_blow_uV;
189
190 ret = clk_prepare_enable(priv->secclk);
191 if (ret) {
192 dev_err(priv->dev, "Failed to enable clock\n");
193 return ret;
194 }
195
196 old->clk_rate = clk_get_rate(priv->secclk);
197 ret = clk_set_rate(priv->secclk, priv->soc_data->qfprom_blow_set_freq);
198 if (ret) {
199 dev_err(priv->dev, "Failed to set clock rate for enable\n");
200 goto err_clk_prepared;
201 }
202
203 /*
204 * Hardware requires a minimum voltage for fuse blowing.
205 * This may be a shared rail so don't specify a maximum.
206 * Regulator constraints will cap to the actual maximum.
207 */
208 ret = regulator_set_voltage(priv->vcc, qfprom_blow_uV, INT_MAX);
209 if (ret) {
210 dev_err(priv->dev, "Failed to set %duV\n", qfprom_blow_uV);
211 goto err_clk_rate_set;
212 }
213
214 ret = regulator_enable(priv->vcc);
215 if (ret) {
216 dev_err(priv->dev, "Failed to enable regulator\n");
217 goto err_clk_rate_set;
218 }
219
220 ret = pm_runtime_resume_and_get(priv->dev);
221 if (ret < 0) {
222 dev_err(priv->dev, "Failed to enable power-domain\n");
223 goto err_reg_enable;
224 }
225 dev_pm_genpd_set_performance_state(priv->dev, INT_MAX);
226
227 old->timer_val = readl(priv->qfpconf + QFPROM_BLOW_TIMER_OFFSET);
228 old->accel_val = readl(priv->qfpconf + QFPROM_ACCEL_OFFSET);
229 writel(priv->soc_data->qfprom_blow_timer_value,
230 priv->qfpconf + QFPROM_BLOW_TIMER_OFFSET);
231 writel(priv->soc_data->accel_value,
232 priv->qfpconf + QFPROM_ACCEL_OFFSET);
233
234 return 0;
235
236 err_reg_enable:
237 regulator_disable(priv->vcc);
238 err_clk_rate_set:
239 clk_set_rate(priv->secclk, old->clk_rate);
240 err_clk_prepared:
241 clk_disable_unprepare(priv->secclk);
242 return ret;
243 }
244
245 /**
246 * qfprom_reg_write() - Write to fuses.
247 * @context: Our driver data.
248 * @reg: The offset to write at.
249 * @_val: Pointer to data to write.
250 * @bytes: The number of bytes to write.
251 *
252 * Writes to fuses. WARNING: THIS IS PERMANENT.
253 *
254 * Return: 0 or -err.
255 */
qfprom_reg_write(void * context,unsigned int reg,void * _val,size_t bytes)256 static int qfprom_reg_write(void *context, unsigned int reg, void *_val,
257 size_t bytes)
258 {
259 struct qfprom_priv *priv = context;
260 struct qfprom_touched_values old;
261 int words = bytes / 4;
262 u32 *value = _val;
263 u32 blow_status;
264 int ret;
265 int i;
266
267 dev_dbg(priv->dev,
268 "Writing to raw qfprom region : %#010x of size: %zu\n",
269 reg, bytes);
270
271 /*
272 * The hardware only allows us to write word at a time, but we can
273 * read byte at a time. Until the nvmem framework allows a separate
274 * word_size and stride for reading vs. writing, we'll enforce here.
275 */
276 if (bytes % 4) {
277 dev_err(priv->dev,
278 "%zu is not an integral number of words\n", bytes);
279 return -EINVAL;
280 }
281 if (reg % 4) {
282 dev_err(priv->dev,
283 "Invalid offset: %#x. Must be word aligned\n", reg);
284 return -EINVAL;
285 }
286
287 ret = qfprom_enable_fuse_blowing(priv, &old);
288 if (ret)
289 return ret;
290
291 ret = readl_relaxed_poll_timeout(
292 priv->qfpconf + QFPROM_BLOW_STATUS_OFFSET,
293 blow_status, blow_status == QFPROM_BLOW_STATUS_READY,
294 QFPROM_FUSE_BLOW_POLL_US, QFPROM_FUSE_BLOW_TIMEOUT_US);
295
296 if (ret) {
297 dev_err(priv->dev,
298 "Timeout waiting for initial ready; aborting.\n");
299 goto exit_enabled_fuse_blowing;
300 }
301
302 for (i = 0; i < words; i++)
303 writel(value[i], priv->qfpraw + reg + (i * 4));
304
305 ret = readl_relaxed_poll_timeout(
306 priv->qfpconf + QFPROM_BLOW_STATUS_OFFSET,
307 blow_status, blow_status == QFPROM_BLOW_STATUS_READY,
308 QFPROM_FUSE_BLOW_POLL_US, QFPROM_FUSE_BLOW_TIMEOUT_US);
309
310 /* Give an error, but not much we can do in this case */
311 if (ret)
312 dev_err(priv->dev, "Timeout waiting for finish.\n");
313
314 exit_enabled_fuse_blowing:
315 qfprom_disable_fuse_blowing(priv, &old);
316
317 return ret;
318 }
319
qfprom_reg_read(void * context,unsigned int reg,void * _val,size_t bytes)320 static int qfprom_reg_read(void *context,
321 unsigned int reg, void *_val, size_t bytes)
322 {
323 struct qfprom_priv *priv = context;
324 u8 *val = _val;
325 int i = 0, words = bytes;
326 void __iomem *base = priv->qfpcorrected;
327
328 if (read_raw_data && priv->qfpraw)
329 base = priv->qfpraw;
330
331 while (words--)
332 *val++ = readb(base + reg + i++);
333
334 return 0;
335 }
336
qfprom_runtime_disable(void * data)337 static void qfprom_runtime_disable(void *data)
338 {
339 pm_runtime_disable(data);
340 }
341
342 static const struct qfprom_soc_data qfprom_7_8_data = {
343 .accel_value = 0xD10,
344 .qfprom_blow_timer_value = 25,
345 .qfprom_blow_set_freq = 4800000,
346 .qfprom_blow_uV = 1800000,
347 };
348
349 static const struct qfprom_soc_data qfprom_7_15_data = {
350 .accel_value = 0xD08,
351 .qfprom_blow_timer_value = 24,
352 .qfprom_blow_set_freq = 4800000,
353 .qfprom_blow_uV = 1900000,
354 };
355
qfprom_probe(struct platform_device * pdev)356 static int qfprom_probe(struct platform_device *pdev)
357 {
358 struct nvmem_config econfig = {
359 .name = "qfprom",
360 .stride = 1,
361 .word_size = 1,
362 .id = NVMEM_DEVID_AUTO,
363 .reg_read = qfprom_reg_read,
364 };
365 struct device *dev = &pdev->dev;
366 struct resource *res;
367 struct nvmem_device *nvmem;
368 const struct qfprom_soc_compatible_data *soc_data;
369 struct qfprom_priv *priv;
370 int ret;
371
372 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
373 if (!priv)
374 return -ENOMEM;
375
376 /* The corrected section is always provided */
377 priv->qfpcorrected = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
378 if (IS_ERR(priv->qfpcorrected))
379 return PTR_ERR(priv->qfpcorrected);
380
381 econfig.size = resource_size(res);
382 econfig.dev = dev;
383 econfig.priv = priv;
384
385 priv->dev = dev;
386 soc_data = device_get_match_data(dev);
387 if (soc_data) {
388 econfig.keepout = soc_data->keepout;
389 econfig.nkeepout = soc_data->nkeepout;
390 }
391
392 /*
393 * If more than one region is provided then the OS has the ability
394 * to write.
395 */
396 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
397 if (res) {
398 u32 version;
399 int major_version, minor_version;
400
401 priv->qfpraw = devm_ioremap_resource(dev, res);
402 if (IS_ERR(priv->qfpraw))
403 return PTR_ERR(priv->qfpraw);
404 priv->qfpconf = devm_platform_ioremap_resource(pdev, 2);
405 if (IS_ERR(priv->qfpconf))
406 return PTR_ERR(priv->qfpconf);
407 priv->qfpsecurity = devm_platform_ioremap_resource(pdev, 3);
408 if (IS_ERR(priv->qfpsecurity))
409 return PTR_ERR(priv->qfpsecurity);
410
411 version = readl(priv->qfpsecurity + QFPROM_VERSION_OFFSET);
412 major_version = (version & QFPROM_MAJOR_VERSION_MASK) >>
413 QFPROM_MAJOR_VERSION_SHIFT;
414 minor_version = (version & QFPROM_MINOR_VERSION_MASK) >>
415 QFPROM_MINOR_VERSION_SHIFT;
416
417 if (major_version == 7 && minor_version == 8)
418 priv->soc_data = &qfprom_7_8_data;
419 else if (major_version == 7 && minor_version == 15)
420 priv->soc_data = &qfprom_7_15_data;
421
422 priv->vcc = devm_regulator_get(&pdev->dev, "vcc");
423 if (IS_ERR(priv->vcc))
424 return PTR_ERR(priv->vcc);
425
426 priv->secclk = devm_clk_get(dev, "core");
427 if (IS_ERR(priv->secclk))
428 return dev_err_probe(dev, PTR_ERR(priv->secclk), "Error getting clock\n");
429
430 /* Only enable writing if we have SoC data. */
431 if (priv->soc_data)
432 econfig.reg_write = qfprom_reg_write;
433 }
434
435 pm_runtime_enable(dev);
436 ret = devm_add_action_or_reset(dev, qfprom_runtime_disable, dev);
437 if (ret)
438 return ret;
439
440 nvmem = devm_nvmem_register(dev, &econfig);
441
442 return PTR_ERR_OR_ZERO(nvmem);
443 }
444
445 static const struct of_device_id qfprom_of_match[] = {
446 { .compatible = "qcom,qfprom",},
447 { .compatible = "qcom,sc7180-qfprom", .data = &sc7180_qfprom},
448 { .compatible = "qcom,sc7280-qfprom", .data = &sc7280_qfprom},
449 {/* sentinel */},
450 };
451 MODULE_DEVICE_TABLE(of, qfprom_of_match);
452
453 static struct platform_driver qfprom_driver = {
454 .probe = qfprom_probe,
455 .driver = {
456 .name = "qcom,qfprom",
457 .of_match_table = qfprom_of_match,
458 },
459 };
460 module_platform_driver(qfprom_driver);
461 MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org>");
462 MODULE_DESCRIPTION("Qualcomm QFPROM driver");
463 MODULE_LICENSE("GPL v2");
464