1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2020 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
4  */
5 
6 #include <linux/bitfield.h>
7 #include <linux/bitops.h>
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/genalloc.h>
11 #include <linux/io.h>
12 #include <linux/mfd/syscon.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/property.h>
16 #include <linux/regmap.h>
17 #include <linux/remoteproc.h>
18 #include <linux/reset.h>
19 #include <linux/sizes.h>
20 
21 #include "remoteproc_internal.h"
22 
23 #define AO_REMAP_REG0						0x0
24 #define AO_REMAP_REG0_REMAP_AHB_SRAM_BITS_17_14_FOR_ARM_CPU	GENMASK(3, 0)
25 
26 #define AO_REMAP_REG1						0x4
27 #define AO_REMAP_REG1_MOVE_AHB_SRAM_TO_0X0_INSTEAD_OF_DDR	BIT(4)
28 #define AO_REMAP_REG1_REMAP_AHB_SRAM_BITS_17_14_FOR_MEDIA_CPU	GENMASK(3, 0)
29 
30 #define AO_CPU_CNTL						0x0
31 #define AO_CPU_CNTL_AHB_SRAM_BITS_31_20				GENMASK(28, 16)
32 #define AO_CPU_CNTL_HALT					BIT(9)
33 #define AO_CPU_CNTL_UNKNONWN					BIT(8)
34 #define AO_CPU_CNTL_RUN						BIT(0)
35 
36 #define AO_CPU_STAT						0x4
37 
38 #define AO_SECURE_REG0						0x0
39 #define AO_SECURE_REG0_AHB_SRAM_BITS_19_12			GENMASK(15, 8)
40 
41 /* Only bits [31:20] and [17:14] are usable, all other bits must be zero */
42 #define MESON_AO_RPROC_SRAM_USABLE_BITS				0xfff3c000ULL
43 
44 #define MESON_AO_RPROC_MEMORY_OFFSET				0x10000000
45 
46 struct meson_mx_ao_arc_rproc_priv {
47 	void __iomem		*remap_base;
48 	void __iomem		*cpu_base;
49 	unsigned long		sram_va;
50 	phys_addr_t		sram_pa;
51 	size_t			sram_size;
52 	struct gen_pool		*sram_pool;
53 	struct reset_control	*arc_reset;
54 	struct clk		*arc_pclk;
55 	struct regmap		*secbus2_regmap;
56 };
57 
58 static int meson_mx_ao_arc_rproc_start(struct rproc *rproc)
59 {
60 	struct meson_mx_ao_arc_rproc_priv *priv = rproc->priv;
61 	phys_addr_t translated_sram_addr;
62 	u32 tmp;
63 	int ret;
64 
65 	ret = clk_prepare_enable(priv->arc_pclk);
66 	if (ret)
67 		return ret;
68 
69 	tmp = FIELD_PREP(AO_REMAP_REG0_REMAP_AHB_SRAM_BITS_17_14_FOR_ARM_CPU,
70 			 priv->sram_pa >> 14);
71 	writel(tmp, priv->remap_base + AO_REMAP_REG0);
72 
73 	/*
74 	 * The SRAM content as seen by the ARC core always starts at 0x0
75 	 * regardless of the value given here (this was discovered by trial and
76 	 * error). For SoCs older than Meson6 we probably have to set
77 	 * AO_REMAP_REG1_MOVE_AHB_SRAM_TO_0X0_INSTEAD_OF_DDR to achieve the
78 	 * same. (At least) For Meson8 and newer that bit must not be set.
79 	 */
80 	writel(0x0, priv->remap_base + AO_REMAP_REG1);
81 
82 	regmap_update_bits(priv->secbus2_regmap, AO_SECURE_REG0,
83 			   AO_SECURE_REG0_AHB_SRAM_BITS_19_12,
84 			   FIELD_PREP(AO_SECURE_REG0_AHB_SRAM_BITS_19_12,
85 				      priv->sram_pa >> 12));
86 
87 	ret = reset_control_reset(priv->arc_reset);
88 	if (ret) {
89 		clk_disable_unprepare(priv->arc_pclk);
90 		return ret;
91 	}
92 
93 	usleep_range(10, 100);
94 
95 	/*
96 	 * Convert from 0xd9000000 to 0xc9000000 as the vendor driver does.
97 	 * This only seems to be relevant for the AO_CPU_CNTL register. It is
98 	 * unknown why this is needed.
99 	 */
100 	translated_sram_addr = priv->sram_pa - MESON_AO_RPROC_MEMORY_OFFSET;
101 
102 	tmp = FIELD_PREP(AO_CPU_CNTL_AHB_SRAM_BITS_31_20,
103 			 translated_sram_addr >> 20);
104 	tmp |= AO_CPU_CNTL_UNKNONWN | AO_CPU_CNTL_RUN;
105 	writel(tmp, priv->cpu_base + AO_CPU_CNTL);
106 
107 	usleep_range(20, 200);
108 
109 	return 0;
110 }
111 
112 static int meson_mx_ao_arc_rproc_stop(struct rproc *rproc)
113 {
114 	struct meson_mx_ao_arc_rproc_priv *priv = rproc->priv;
115 
116 	writel(AO_CPU_CNTL_HALT, priv->cpu_base + AO_CPU_CNTL);
117 
118 	clk_disable_unprepare(priv->arc_pclk);
119 
120 	return 0;
121 }
122 
123 static void *meson_mx_ao_arc_rproc_da_to_va(struct rproc *rproc, u64 da,
124 					    size_t len, bool *is_iomem)
125 {
126 	struct meson_mx_ao_arc_rproc_priv *priv = rproc->priv;
127 
128 	/* The memory from the ARC core's perspective always starts at 0x0. */
129 	if ((da + len) > priv->sram_size)
130 		return NULL;
131 
132 	return (void *)priv->sram_va + da;
133 }
134 
135 static struct rproc_ops meson_mx_ao_arc_rproc_ops = {
136 	.start		= meson_mx_ao_arc_rproc_start,
137 	.stop		= meson_mx_ao_arc_rproc_stop,
138 	.da_to_va	= meson_mx_ao_arc_rproc_da_to_va,
139 	.get_boot_addr	= rproc_elf_get_boot_addr,
140 	.load		= rproc_elf_load_segments,
141 	.sanity_check	= rproc_elf_sanity_check,
142 };
143 
144 static int meson_mx_ao_arc_rproc_probe(struct platform_device *pdev)
145 {
146 	struct meson_mx_ao_arc_rproc_priv *priv;
147 	struct device *dev = &pdev->dev;
148 	const char *fw_name = NULL;
149 	struct rproc *rproc;
150 	int ret;
151 
152 	device_property_read_string(dev, "firmware-name", &fw_name);
153 
154 	rproc = devm_rproc_alloc(dev, "meson-mx-ao-arc",
155 				 &meson_mx_ao_arc_rproc_ops, fw_name,
156 				 sizeof(*priv));
157 	if (!rproc)
158 		return -ENOMEM;
159 
160 	rproc->has_iommu = false;
161 	priv = rproc->priv;
162 
163 	priv->sram_pool = of_gen_pool_get(dev->of_node, "sram", 0);
164 	if (!priv->sram_pool) {
165 		dev_err(dev, "Could not get SRAM pool\n");
166 		return -ENODEV;
167 	}
168 
169 	priv->sram_size = gen_pool_avail(priv->sram_pool);
170 
171 	priv->sram_va = gen_pool_alloc(priv->sram_pool, priv->sram_size);
172 	if (!priv->sram_va) {
173 		dev_err(dev, "Could not alloc memory in SRAM pool\n");
174 		return -ENOMEM;
175 	}
176 
177 	priv->sram_pa = gen_pool_virt_to_phys(priv->sram_pool, priv->sram_va);
178 	if (priv->sram_pa & ~MESON_AO_RPROC_SRAM_USABLE_BITS) {
179 		dev_err(dev, "SRAM address contains unusable bits\n");
180 		ret = -EINVAL;
181 		goto err_free_genpool;
182 	}
183 
184 	priv->secbus2_regmap = syscon_regmap_lookup_by_phandle(dev->of_node,
185 							       "amlogic,secbus2");
186 	if (IS_ERR(priv->secbus2_regmap)) {
187 		dev_err(dev, "Failed to find SECBUS2 regmap\n");
188 		ret = PTR_ERR(priv->secbus2_regmap);
189 		goto err_free_genpool;
190 	}
191 
192 	priv->remap_base = devm_platform_ioremap_resource_byname(pdev, "remap");
193 	if (IS_ERR(priv->remap_base)) {
194 		ret = PTR_ERR(priv->remap_base);
195 		goto err_free_genpool;
196 	}
197 
198 	priv->cpu_base = devm_platform_ioremap_resource_byname(pdev, "cpu");
199 	if (IS_ERR(priv->cpu_base)) {
200 		ret = PTR_ERR(priv->cpu_base);
201 		goto err_free_genpool;
202 	}
203 
204 	priv->arc_reset = devm_reset_control_get_exclusive(dev, NULL);
205 	if (IS_ERR(priv->arc_reset)) {
206 		dev_err(dev, "Failed to get ARC reset\n");
207 		ret = PTR_ERR(priv->arc_reset);
208 		goto err_free_genpool;
209 	}
210 
211 	priv->arc_pclk = devm_clk_get(dev, NULL);
212 	if (IS_ERR(priv->arc_pclk)) {
213 		dev_err(dev, "Failed to get the ARC PCLK\n");
214 		ret = PTR_ERR(priv->arc_pclk);
215 		goto err_free_genpool;
216 	}
217 
218 	platform_set_drvdata(pdev, rproc);
219 
220 	ret = rproc_add(rproc);
221 	if (ret)
222 		goto err_free_genpool;
223 
224 	return 0;
225 
226 err_free_genpool:
227 	gen_pool_free(priv->sram_pool, priv->sram_va, priv->sram_size);
228 	return ret;
229 }
230 
231 static int meson_mx_ao_arc_rproc_remove(struct platform_device *pdev)
232 {
233 	struct rproc *rproc = platform_get_drvdata(pdev);
234 	struct meson_mx_ao_arc_rproc_priv *priv = rproc->priv;
235 
236 	rproc_del(rproc);
237 	gen_pool_free(priv->sram_pool, priv->sram_va, priv->sram_size);
238 
239 	return 0;
240 }
241 
242 static const struct of_device_id meson_mx_ao_arc_rproc_match[] = {
243 	{ .compatible = "amlogic,meson8-ao-arc" },
244 	{ .compatible = "amlogic,meson8b-ao-arc" },
245 	{ /* sentinel */ }
246 };
247 MODULE_DEVICE_TABLE(of, meson_mx_ao_arc_rproc_match);
248 
249 static struct platform_driver meson_mx_ao_arc_rproc_driver = {
250 	.probe = meson_mx_ao_arc_rproc_probe,
251 	.remove = meson_mx_ao_arc_rproc_remove,
252 	.driver = {
253 		.name = "meson-mx-ao-arc-rproc",
254 		.of_match_table = meson_mx_ao_arc_rproc_match,
255 	},
256 };
257 module_platform_driver(meson_mx_ao_arc_rproc_driver);
258 
259 MODULE_DESCRIPTION("Amlogic Meson6/8/8b/8m2 AO ARC remote processor driver");
260 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
261 MODULE_LICENSE("GPL v2");
262