[thirdparty/u-boot.git] / drivers / misc / ls2_sfp.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
 *
 * This driver supports the Security Fuse Processor device found on some
 * Layerscape processors. At the moment, we only support a few processors.
 * This driver was written with reference to the Layerscape SDK User
 * Guide [1] and the ATF SFP driver [2].
 *
 * [1] https://docs.nxp.com/bundle/GUID-487B2E69-BB19-42CB-AC38-7EF18C0FE3AE/page/GUID-27FC40AD-3321-4A82-B29E-7BB49EE94F23.html
 * [2] https://source.codeaurora.org/external/qoriq/qoriq-components/atf/tree/drivers/nxp/sfp?h=github.com/master
 */

#define LOG_CATEGORY UCLASS_MISC
#include <common.h>
#include <clk.h>
#include <fuse.h>
#include <misc.h>
#include <asm/io.h>
#include <dm/device_compat.h>
#include <dm/read.h>
#include <linux/bitfield.h>
#include <power/regulator.h>

DECLARE_GLOBAL_DATA_PTR;

#define SFP_INGR	0x20
#define SFP_SVHESR	0x24
#define SFP_SFPCR	0x28

#define SFP_START	0x200
#define SFP_END		0x284
#define SFP_SIZE	(SFP_END - SFP_START + 4)

#define SFP_INGR_ERR	BIT(8)
#define SFP_INGR_INST	GENMASK(7, 0)

#define SFP_INGR_READFB	0x01
#define SFP_INGR_PROGFB	0x02

#define SFP_SFPCR_PPW	GENMASK(15, 0)

enum ls2_sfp_ioctl {
	LS2_SFP_IOCTL_READ,
	LS2_SFP_IOCTL_PROG,
};

/**
 * struct ls2_sfp_priv - private data for LS2 SFP
 * @base: Base address of SFP
 * @supply: The (optional) supply for TA_PROG_SFP
 * @programmed: Whether we've already programmed the fuses since the last
 *              reset. The SFP has a *very* limited amount of programming
 *              cycles (two to six, depending on the model), so we try and
 *              prevent accidentally performing additional programming
 *              cycles.
 * @dirty: Whether the mirror registers have been written to (overridden)
 *         since we've last read the fuses (either as part of the reset
 *         process or using a READFB instruction). There is a much larger,
 *         but still finite, limit on the number of SFP read cycles (around
 *         300,000), so we try and minimize reads as well.
 */
struct ls2_sfp_priv {
	void __iomem *base;
	struct udevice *supply;
	bool programmed, dirty;
};

static u32 ls2_sfp_readl(struct ls2_sfp_priv *priv, ulong off)
{
	u32 val = be32_to_cpu(readl(priv->base + off));

	log_debug("%08x = readl(%p)\n", val, priv->base + off);
	return val;
}

static void ls2_sfp_writel(struct ls2_sfp_priv *priv, ulong val, ulong off)
{
	log_debug("writel(%08lx, %p)\n", val, priv->base + off);
	writel(cpu_to_be32(val), priv->base + off);
}

static bool ls2_sfp_validate(struct udevice *dev, int offset, int size)
{
	if (offset < 0 || size < 0) {
		dev_notice(dev, "size and offset must be positive\n");
		return false;
	}

	if (offset & 3 || size & 3) {
		dev_notice(dev, "size and offset must be multiples of 4\n");
		return false;
	}

	if (offset + size > SFP_SIZE) {
		dev_notice(dev, "size + offset must be <= %#x\n", SFP_SIZE);
		return false;
	}

	return true;
}

static int ls2_sfp_read(struct udevice *dev, int offset, void *buf_bytes,
			int size)
{
	int i;
	struct ls2_sfp_priv *priv = dev_get_priv(dev);
	u32 *buf = buf_bytes;

	if (!ls2_sfp_validate(dev, offset, size))
		return -EINVAL;

	for (i = 0; i < size; i += 4)
		buf[i >> 2] = ls2_sfp_readl(priv, SFP_START + offset + i);

	return size;
}

static int ls2_sfp_write(struct udevice *dev, int offset,
			 const void *buf_bytes, int size)
{
	int i;
	struct ls2_sfp_priv *priv = dev_get_priv(dev);
	const u32 *buf = buf_bytes;

	if (!ls2_sfp_validate(dev, offset, size))
		return -EINVAL;

	for (i = 0; i < size; i += 4)
		ls2_sfp_writel(priv, buf[i >> 2], SFP_START + offset + i);

	priv->dirty = true;
	return size;
}

static int ls2_sfp_check_secret(struct udevice *dev)
{
	struct ls2_sfp_priv *priv = dev_get_priv(dev);
	u32 svhesr = ls2_sfp_readl(priv, SFP_SVHESR);

	if (svhesr) {
		dev_warn(dev, "secret value hamming error not zero: %08x\n",
			 svhesr);
		return -EIO;
	}
	return 0;
}

static int ls2_sfp_transaction(struct ls2_sfp_priv *priv, ulong inst)
{
	u32 ingr;

	ls2_sfp_writel(priv, inst, SFP_INGR);

	do {
		ingr = ls2_sfp_readl(priv, SFP_INGR);
	} while (FIELD_GET(SFP_INGR_INST, ingr));

	return FIELD_GET(SFP_INGR_ERR, ingr) ? -EIO : 0;
}

static int ls2_sfp_ioctl(struct udevice *dev, unsigned long request, void *buf)
{
	int ret;
	struct ls2_sfp_priv *priv = dev_get_priv(dev);

	switch (request) {
	case LS2_SFP_IOCTL_READ:
		if (!priv->dirty) {
			dev_dbg(dev, "ignoring read request, since fuses are not dirty\n");
			return 0;
		}

		ret = ls2_sfp_transaction(priv, SFP_INGR_READFB);
		if (ret) {
			dev_err(dev, "error reading fuses\n");
			return ret;
		}

		ls2_sfp_check_secret(dev);
		priv->dirty = false;
		return 0;
	case LS2_SFP_IOCTL_PROG:
		if (priv->programmed) {
			dev_warn(dev, "fuses already programmed\n");
			return -EPERM;
		}

		ret = ls2_sfp_check_secret(dev);
		if (ret)
			return ret;

		if (priv->supply) {
			ret = regulator_set_enable(priv->supply, true);
			if (ret)
				return ret;
		}

		ret = ls2_sfp_transaction(priv, SFP_INGR_PROGFB);
		priv->programmed = true;
		if (priv->supply)
			regulator_set_enable(priv->supply, false);

		if (ret)
			dev_err(dev, "error programming fuses\n");
		return ret;
	default:
		dev_dbg(dev, "unknown ioctl %lu\n", request);
		return -EINVAL;
	}
}

static const struct misc_ops ls2_sfp_ops = {
	.read = ls2_sfp_read,
	.write = ls2_sfp_write,
	.ioctl = ls2_sfp_ioctl,
};

static int ls2_sfp_probe(struct udevice *dev)
{
	int ret;
	struct clk clk;
	struct ls2_sfp_priv *priv = dev_get_priv(dev);
	ulong rate;

	priv->base = dev_read_addr_ptr(dev);
	if (!priv->base) {
		dev_dbg(dev, "could not read register base\n");
		return -EINVAL;
	}

	ret = device_get_supply_regulator(dev, "ta-sfp-prog-supply", &priv->supply);
	if (ret && ret != -ENODEV && ret != -ENOSYS) {
		dev_dbg(dev, "problem getting supply (err %d)\n", ret);
		return ret;
	}

	ret = clk_get_by_name(dev, "sfp", &clk);
	if (ret == -ENOSYS) {
		rate = gd->bus_clk / 4;
	} else if (ret) {
		dev_dbg(dev, "could not get clock (err %d)\n", ret);
		return ret;
	} else {
		ret = clk_enable(&clk);
		if (ret) {
			dev_dbg(dev, "could not enable clock (err %d)\n", ret);
			return ret;
		}

		rate = clk_get_rate(&clk);
		if (!rate || IS_ERR_VALUE(rate)) {
			ret = rate ? rate : -ENOENT;
			dev_dbg(dev, "could not get clock rate (err %d)\n",
				ret);
			return ret;
		}
	}

	/* sfp clock in MHz * 12 */
	ls2_sfp_writel(priv, FIELD_PREP(SFP_SFPCR_PPW, rate * 12 / 1000000),
		       SFP_SFPCR);

	ls2_sfp_check_secret(dev);
	return 0;
}

static const struct udevice_id ls2_sfp_ids[] = {
	{ .compatible = "fsl,ls1021a-sfp" },
	{ }
};

U_BOOT_DRIVER(ls2_sfp) = {
	.name		= "ls2_sfp",
	.id		= UCLASS_MISC,
	.of_match	= ls2_sfp_ids,
	.probe		= ls2_sfp_probe,
	.ops		= &ls2_sfp_ops,
	.priv_auto	= sizeof(struct ls2_sfp_priv),
};

static int ls2_sfp_device(struct udevice **dev)
{
	int ret = uclass_get_device_by_driver(UCLASS_MISC,
					      DM_DRIVER_GET(ls2_sfp), dev);

	if (ret)
		log_debug("device not found (err %d)\n", ret);
	return ret;
}

int fuse_read(u32 bank, u32 word, u32 *val)
{
	int ret;
	struct udevice *dev;

	ret = ls2_sfp_device(&dev);
	if (ret)
		return ret;

	ret = misc_ioctl(dev, LS2_SFP_IOCTL_READ, NULL);
	if (ret)
		return ret;

	ret = misc_read(dev, word << 2, val, sizeof(*val));
	return ret < 0 ? ret : 0;
}

int fuse_sense(u32 bank, u32 word, u32 *val)
{
	int ret;
	struct udevice *dev;

	ret = ls2_sfp_device(&dev);
	if (ret)
		return ret;

	ret = misc_read(dev, word << 2, val, sizeof(*val));
	return ret < 0 ? ret : 0;
}

int fuse_prog(u32 bank, u32 word, u32 val)
{
	int ret;
	struct udevice *dev;

	ret = ls2_sfp_device(&dev);
	if (ret)
		return ret;

	ret = misc_write(dev, word << 2, &val, sizeof(val));
	if (ret < 0)
		return ret;

	return misc_ioctl(dev, LS2_SFP_IOCTL_PROG, NULL);
}

int fuse_override(u32 bank, u32 word, u32 val)
{
	int ret;
	struct udevice *dev;

	ret = ls2_sfp_device(&dev);
	if (ret)
		return ret;

	ret = misc_write(dev, word << 2, &val, sizeof(val));
	return ret < 0 ? ret : 0;
}
Commit	Line	Data
2645bc0e SA	1	// 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
d678a59d	15	#include <common.h>
2645bc0e SA	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
	25	DECLARE_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
	43	enum 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	*/
	63	struct ls2_sfp_priv {
	64	void __iomem *base;
	65	struct udevice *supply;
	66	bool programmed, dirty;
	67	};
	68
	69	static 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
	77	static 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
83	static 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
103	static 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
119	static 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
136	static 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
149	static 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
162	static 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
213	static const struct misc_ops ls2_sfp_ops = {
214	.read = ls2_sfp_read,
215	.write = ls2_sfp_write,
216	.ioctl = ls2_sfp_ioctl,
217	};
218
219	static 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
4992d836	232	ret = device_get_supply_regulator(dev, "ta-sfp-prog-supply", &priv->supply);
2645bc0e SA	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);
2645bc0e SA	252	if (!rate \|\| IS_ERR_VALUE(rate)) {
	253	ret = rate ? rate : -ENOENT;
	254	dev_dbg(dev, "could not get clock rate (err %d)\n",
	255	ret);
	256	return ret;
	257	}
	258	}
	259
	260	/* sfp clock in MHz * 12 */
	261	ls2_sfp_writel(priv, FIELD_PREP(SFP_SFPCR_PPW, rate * 12 / 1000000),
	262	SFP_SFPCR);
	263
	264	ls2_sfp_check_secret(dev);
	265	return 0;
	266	}
	267
	268	static const struct udevice_id ls2_sfp_ids[] = {
	269	{ .compatible = "fsl,ls1021a-sfp" },
	270	{ }
	271	};
	272
	273	U_BOOT_DRIVER(ls2_sfp) = {
	274	.name = "ls2_sfp",
	275	.id = UCLASS_MISC,
	276	.of_match = ls2_sfp_ids,
	277	.probe = ls2_sfp_probe,
	278	.ops = &ls2_sfp_ops,
	279	.priv_auto = sizeof(struct ls2_sfp_priv),
	280	};
	281
	282	static int ls2_sfp_device(struct udevice **dev)
	283	{
	284	int ret = uclass_get_device_by_driver(UCLASS_MISC,
	285	DM_DRIVER_GET(ls2_sfp), dev);
	286
	287	if (ret)
	288	log_debug("device not found (err %d)\n", ret);
	289	return ret;
	290	}
	291
	292	int fuse_read(u32 bank, u32 word, u32 *val)
	293	{
	294	int ret;
	295	struct udevice *dev;
	296
	297	ret = ls2_sfp_device(&dev);
	298	if (ret)
	299	return ret;
	300
	301	ret = misc_ioctl(dev, LS2_SFP_IOCTL_READ, NULL);
	302	if (ret)
	303	return ret;
	304
	305	ret = misc_read(dev, word << 2, val, sizeof(*val));
	306	return ret < 0 ? ret : 0;
	307	}
	308
	309	int fuse_sense(u32 bank, u32 word, u32 *val)
	310	{
	311	int ret;
	312	struct udevice *dev;
	313
	314	ret = ls2_sfp_device(&dev);
	315	if (ret)
316	return ret;
317
318	ret = misc_read(dev, word << 2, val, sizeof(*val));
319	return ret < 0 ? ret : 0;
320	}
321
322	int fuse_prog(u32 bank, u32 word, u32 val)
323	{
324	int ret;
325	struct udevice *dev;
326
327	ret = ls2_sfp_device(&dev);
328	if (ret)
329	return ret;
330
331	ret = misc_write(dev, word << 2, &val, sizeof(val));
332	if (ret < 0)
333	return ret;
334
335	return misc_ioctl(dev, LS2_SFP_IOCTL_PROG, NULL);
336	}
337
338	int fuse_override(u32 bank, u32 word, u32 val)
339	{
340	int ret;
341	struct udevice *dev;
342
343	ret = ls2_sfp_device(&dev);
344	if (ret)
345	return ret;
346
347	ret = misc_write(dev, word << 2, &val, sizeof(val));
348	return ret < 0 ? ret : 0;
349	}