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
39static bool read_raw_data;
40module_param(read_raw_data, bool, 0644);
41MODULE_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 */
52struct 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 */
72struct 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 */
90struct 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 */
103struct qfprom_soc_compatible_data {
104	const struct nvmem_keepout *keepout;
105	unsigned int nkeepout;
106};
107
108static const struct nvmem_keepout sc7180_qfprom_keepout[] = {
109	{.start = 0x128, .end = 0x148},
110	{.start = 0x220, .end = 0x228}
111};
112
113static const struct qfprom_soc_compatible_data sc7180_qfprom = {
114	.keepout = sc7180_qfprom_keepout,
115	.nkeepout = ARRAY_SIZE(sc7180_qfprom_keepout)
116};
117
118static const struct nvmem_keepout sc7280_qfprom_keepout[] = {
119	{.start = 0x128, .end = 0x148},
120	{.start = 0x238, .end = 0x248}
121};
122
123static 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 */
139static 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 */
184static 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
236err_reg_enable:
237	regulator_disable(priv->vcc);
238err_clk_rate_set:
239	clk_set_rate(priv->secclk, old->clk_rate);
240err_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 */
256static 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
314exit_enabled_fuse_blowing:
315	qfprom_disable_fuse_blowing(priv, &old);
316
317	return ret;
318}
319
320static 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
337static void qfprom_runtime_disable(void *data)
338{
339	pm_runtime_disable(data);
340}
341
342static 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
349static 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
356static int qfprom_probe(struct platform_device *pdev)
357{
358	struct nvmem_config econfig = {
359		.name = "qfprom",
360		.add_legacy_fixed_of_cells = true,
361		.stride = 1,
362		.word_size = 1,
363		.id = NVMEM_DEVID_AUTO,
364		.reg_read = qfprom_reg_read,
365	};
366	struct device *dev = &pdev->dev;
367	struct resource *res;
368	struct nvmem_device *nvmem;
369	const struct qfprom_soc_compatible_data *soc_data;
370	struct qfprom_priv *priv;
371	int ret;
372
373	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
374	if (!priv)
375		return -ENOMEM;
376
377	/* The corrected section is always provided */
378	priv->qfpcorrected = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
379	if (IS_ERR(priv->qfpcorrected))
380		return PTR_ERR(priv->qfpcorrected);
381
382	econfig.size = resource_size(res);
383	econfig.dev = dev;
384	econfig.priv = priv;
385
386	priv->dev = dev;
387	soc_data = device_get_match_data(dev);
388	if (soc_data) {
389		econfig.keepout = soc_data->keepout;
390		econfig.nkeepout = soc_data->nkeepout;
391	}
392
393	/*
394	 * If more than one region is provided then the OS has the ability
395	 * to write.
396	 */
397	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
398	if (res) {
399		u32 version;
400		int major_version, minor_version;
401
402		priv->qfpraw = devm_ioremap_resource(dev, res);
403		if (IS_ERR(priv->qfpraw))
404			return PTR_ERR(priv->qfpraw);
405		priv->qfpconf = devm_platform_ioremap_resource(pdev, 2);
406		if (IS_ERR(priv->qfpconf))
407			return PTR_ERR(priv->qfpconf);
408		priv->qfpsecurity = devm_platform_ioremap_resource(pdev, 3);
409		if (IS_ERR(priv->qfpsecurity))
410			return PTR_ERR(priv->qfpsecurity);
411
412		version = readl(priv->qfpsecurity + QFPROM_VERSION_OFFSET);
413		major_version = (version & QFPROM_MAJOR_VERSION_MASK) >>
414				QFPROM_MAJOR_VERSION_SHIFT;
415		minor_version = (version & QFPROM_MINOR_VERSION_MASK) >>
416				QFPROM_MINOR_VERSION_SHIFT;
417
418		if (major_version == 7 && minor_version == 8)
419			priv->soc_data = &qfprom_7_8_data;
420		else if (major_version == 7 && minor_version == 15)
421			priv->soc_data = &qfprom_7_15_data;
422
423		priv->vcc = devm_regulator_get(&pdev->dev, "vcc");
424		if (IS_ERR(priv->vcc))
425			return PTR_ERR(priv->vcc);
426
427		priv->secclk = devm_clk_get_optional(dev, "core");
428		if (IS_ERR(priv->secclk))
429			return dev_err_probe(dev, PTR_ERR(priv->secclk), "Error getting clock\n");
430
431		/* Only enable writing if we have SoC data and a valid clock */
432		if (priv->soc_data && priv->secclk)
433			econfig.reg_write = qfprom_reg_write;
434	}
435
436	pm_runtime_enable(dev);
437	ret = devm_add_action_or_reset(dev, qfprom_runtime_disable, dev);
438	if (ret)
439		return ret;
440
441	nvmem = devm_nvmem_register(dev, &econfig);
442
443	return PTR_ERR_OR_ZERO(nvmem);
444}
445
446static const struct of_device_id qfprom_of_match[] = {
447	{ .compatible = "qcom,qfprom",},
448	{ .compatible = "qcom,sc7180-qfprom", .data = &sc7180_qfprom},
449	{ .compatible = "qcom,sc7280-qfprom", .data = &sc7280_qfprom},
450	{/* sentinel */},
451};
452MODULE_DEVICE_TABLE(of, qfprom_of_match);
453
454static struct platform_driver qfprom_driver = {
455	.probe = qfprom_probe,
456	.driver = {
457		.name = "qcom,qfprom",
458		.of_match_table = qfprom_of_match,
459	},
460};
461module_platform_driver(qfprom_driver);
462MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org>");
463MODULE_DESCRIPTION("Qualcomm QFPROM driver");
464MODULE_LICENSE("GPL v2");
465