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1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* | |
3 | * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC | |
4 | * | |
5 | * Authors: | |
6 | * Serge Semin <Sergey.Semin@baikalelectronics.ru> | |
7 | * | |
8 | * Baikal-T1 CM2 L2-cache Control Block driver. | |
9 | */ | |
10 | ||
11 | #include <linux/kernel.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/bitfield.h> | |
14 | #include <linux/types.h> | |
15 | #include <linux/device.h> | |
16 | #include <linux/platform_device.h> | |
17 | #include <linux/regmap.h> | |
18 | #include <linux/mfd/syscon.h> | |
19 | #include <linux/sysfs.h> | |
20 | #include <linux/of.h> | |
21 | ||
22 | #define L2_CTL_REG 0x028 | |
23 | #define L2_CTL_DATA_STALL_FLD 0 | |
24 | #define L2_CTL_DATA_STALL_MASK GENMASK(1, L2_CTL_DATA_STALL_FLD) | |
25 | #define L2_CTL_TAG_STALL_FLD 2 | |
26 | #define L2_CTL_TAG_STALL_MASK GENMASK(3, L2_CTL_TAG_STALL_FLD) | |
27 | #define L2_CTL_WS_STALL_FLD 4 | |
28 | #define L2_CTL_WS_STALL_MASK GENMASK(5, L2_CTL_WS_STALL_FLD) | |
29 | #define L2_CTL_SET_CLKRATIO BIT(13) | |
30 | #define L2_CTL_CLKRATIO_LOCK BIT(31) | |
31 | ||
32 | #define L2_CTL_STALL_MIN 0 | |
33 | #define L2_CTL_STALL_MAX 3 | |
34 | #define L2_CTL_STALL_SET_DELAY_US 1 | |
35 | #define L2_CTL_STALL_SET_TOUT_US 1000 | |
36 | ||
37 | /* | |
38 | * struct l2_ctl - Baikal-T1 L2 Control block private data. | |
39 | * @dev: Pointer to the device structure. | |
40 | * @sys_regs: Baikal-T1 System Controller registers map. | |
41 | */ | |
42 | struct l2_ctl { | |
43 | struct device *dev; | |
44 | ||
45 | struct regmap *sys_regs; | |
46 | }; | |
47 | ||
48 | /* | |
49 | * enum l2_ctl_stall - Baikal-T1 L2-cache-RAM stall identifier. | |
50 | * @L2_WSSTALL: Way-select latency. | |
51 | * @L2_TAGSTALL: Tag latency. | |
52 | * @L2_DATASTALL: Data latency. | |
53 | */ | |
54 | enum l2_ctl_stall { | |
55 | L2_WS_STALL, | |
56 | L2_TAG_STALL, | |
57 | L2_DATA_STALL | |
58 | }; | |
59 | ||
60 | /* | |
61 | * struct l2_ctl_device_attribute - Baikal-T1 L2-cache device attribute. | |
62 | * @dev_attr: Actual sysfs device attribute. | |
63 | * @id: L2-cache stall field identifier. | |
64 | */ | |
65 | struct l2_ctl_device_attribute { | |
66 | struct device_attribute dev_attr; | |
67 | enum l2_ctl_stall id; | |
68 | }; | |
7f04614b | 69 | |
83ca8b3e SS |
70 | #define to_l2_ctl_dev_attr(_dev_attr) \ |
71 | container_of(_dev_attr, struct l2_ctl_device_attribute, dev_attr) | |
72 | ||
73 | #define L2_CTL_ATTR_RW(_name, _prefix, _id) \ | |
74 | struct l2_ctl_device_attribute l2_ctl_attr_##_name = \ | |
75 | { __ATTR(_name, 0644, _prefix##_show, _prefix##_store), _id } | |
76 | ||
77 | static int l2_ctl_get_latency(struct l2_ctl *l2, enum l2_ctl_stall id, u32 *val) | |
78 | { | |
79 | u32 data = 0; | |
80 | int ret; | |
81 | ||
82 | ret = regmap_read(l2->sys_regs, L2_CTL_REG, &data); | |
83 | if (ret) | |
84 | return ret; | |
85 | ||
86 | switch (id) { | |
87 | case L2_WS_STALL: | |
88 | *val = FIELD_GET(L2_CTL_WS_STALL_MASK, data); | |
89 | break; | |
90 | case L2_TAG_STALL: | |
91 | *val = FIELD_GET(L2_CTL_TAG_STALL_MASK, data); | |
92 | break; | |
93 | case L2_DATA_STALL: | |
94 | *val = FIELD_GET(L2_CTL_DATA_STALL_MASK, data); | |
95 | break; | |
96 | default: | |
97 | return -EINVAL; | |
98 | } | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
103 | static int l2_ctl_set_latency(struct l2_ctl *l2, enum l2_ctl_stall id, u32 val) | |
104 | { | |
105 | u32 mask = 0, data = 0; | |
106 | int ret; | |
107 | ||
108 | val = clamp_val(val, L2_CTL_STALL_MIN, L2_CTL_STALL_MAX); | |
109 | ||
110 | switch (id) { | |
111 | case L2_WS_STALL: | |
112 | data = FIELD_PREP(L2_CTL_WS_STALL_MASK, val); | |
113 | mask = L2_CTL_WS_STALL_MASK; | |
114 | break; | |
115 | case L2_TAG_STALL: | |
116 | data = FIELD_PREP(L2_CTL_TAG_STALL_MASK, val); | |
117 | mask = L2_CTL_TAG_STALL_MASK; | |
118 | break; | |
119 | case L2_DATA_STALL: | |
120 | data = FIELD_PREP(L2_CTL_DATA_STALL_MASK, val); | |
121 | mask = L2_CTL_DATA_STALL_MASK; | |
122 | break; | |
123 | default: | |
124 | return -EINVAL; | |
125 | } | |
126 | ||
127 | data |= L2_CTL_SET_CLKRATIO; | |
128 | mask |= L2_CTL_SET_CLKRATIO; | |
129 | ||
130 | ret = regmap_update_bits(l2->sys_regs, L2_CTL_REG, mask, data); | |
131 | if (ret) | |
132 | return ret; | |
133 | ||
134 | return regmap_read_poll_timeout(l2->sys_regs, L2_CTL_REG, data, | |
135 | data & L2_CTL_CLKRATIO_LOCK, | |
136 | L2_CTL_STALL_SET_DELAY_US, | |
137 | L2_CTL_STALL_SET_TOUT_US); | |
138 | } | |
139 | ||
140 | static void l2_ctl_clear_data(void *data) | |
141 | { | |
142 | struct l2_ctl *l2 = data; | |
143 | struct platform_device *pdev = to_platform_device(l2->dev); | |
144 | ||
145 | platform_set_drvdata(pdev, NULL); | |
146 | } | |
147 | ||
148 | static struct l2_ctl *l2_ctl_create_data(struct platform_device *pdev) | |
149 | { | |
150 | struct device *dev = &pdev->dev; | |
151 | struct l2_ctl *l2; | |
152 | int ret; | |
153 | ||
154 | l2 = devm_kzalloc(dev, sizeof(*l2), GFP_KERNEL); | |
155 | if (!l2) | |
156 | return ERR_PTR(-ENOMEM); | |
157 | ||
158 | ret = devm_add_action(dev, l2_ctl_clear_data, l2); | |
159 | if (ret) { | |
160 | dev_err(dev, "Can't add L2 CTL data clear action\n"); | |
161 | return ERR_PTR(ret); | |
162 | } | |
163 | ||
164 | l2->dev = dev; | |
165 | platform_set_drvdata(pdev, l2); | |
166 | ||
167 | return l2; | |
168 | } | |
169 | ||
170 | static int l2_ctl_find_sys_regs(struct l2_ctl *l2) | |
171 | { | |
172 | l2->sys_regs = syscon_node_to_regmap(l2->dev->of_node->parent); | |
173 | if (IS_ERR(l2->sys_regs)) { | |
174 | dev_err(l2->dev, "Couldn't get L2 CTL register map\n"); | |
175 | return PTR_ERR(l2->sys_regs); | |
176 | } | |
177 | ||
178 | return 0; | |
179 | } | |
180 | ||
181 | static int l2_ctl_of_parse_property(struct l2_ctl *l2, enum l2_ctl_stall id, | |
182 | const char *propname) | |
183 | { | |
184 | int ret = 0; | |
185 | u32 data; | |
186 | ||
187 | if (!of_property_read_u32(l2->dev->of_node, propname, &data)) { | |
188 | ret = l2_ctl_set_latency(l2, id, data); | |
189 | if (ret) | |
190 | dev_err(l2->dev, "Invalid value of '%s'\n", propname); | |
191 | } | |
192 | ||
193 | return ret; | |
194 | } | |
195 | ||
196 | static int l2_ctl_of_parse(struct l2_ctl *l2) | |
197 | { | |
198 | int ret; | |
199 | ||
200 | ret = l2_ctl_of_parse_property(l2, L2_WS_STALL, "baikal,l2-ws-latency"); | |
201 | if (ret) | |
202 | return ret; | |
203 | ||
204 | ret = l2_ctl_of_parse_property(l2, L2_TAG_STALL, "baikal,l2-tag-latency"); | |
205 | if (ret) | |
206 | return ret; | |
207 | ||
208 | return l2_ctl_of_parse_property(l2, L2_DATA_STALL, | |
209 | "baikal,l2-data-latency"); | |
210 | } | |
211 | ||
212 | static ssize_t l2_ctl_latency_show(struct device *dev, | |
213 | struct device_attribute *attr, | |
214 | char *buf) | |
215 | { | |
216 | struct l2_ctl_device_attribute *devattr = to_l2_ctl_dev_attr(attr); | |
217 | struct l2_ctl *l2 = dev_get_drvdata(dev); | |
218 | u32 data; | |
219 | int ret; | |
220 | ||
221 | ret = l2_ctl_get_latency(l2, devattr->id, &data); | |
222 | if (ret) | |
223 | return ret; | |
224 | ||
225 | return scnprintf(buf, PAGE_SIZE, "%u\n", data); | |
226 | } | |
227 | ||
228 | static ssize_t l2_ctl_latency_store(struct device *dev, | |
229 | struct device_attribute *attr, | |
230 | const char *buf, size_t count) | |
231 | { | |
232 | struct l2_ctl_device_attribute *devattr = to_l2_ctl_dev_attr(attr); | |
233 | struct l2_ctl *l2 = dev_get_drvdata(dev); | |
234 | u32 data; | |
235 | int ret; | |
236 | ||
237 | if (kstrtouint(buf, 0, &data) < 0) | |
238 | return -EINVAL; | |
239 | ||
240 | ret = l2_ctl_set_latency(l2, devattr->id, data); | |
241 | if (ret) | |
242 | return ret; | |
243 | ||
244 | return count; | |
245 | } | |
7f04614b | 246 | |
83ca8b3e SS |
247 | static L2_CTL_ATTR_RW(l2_ws_latency, l2_ctl_latency, L2_WS_STALL); |
248 | static L2_CTL_ATTR_RW(l2_tag_latency, l2_ctl_latency, L2_TAG_STALL); | |
249 | static L2_CTL_ATTR_RW(l2_data_latency, l2_ctl_latency, L2_DATA_STALL); | |
250 | ||
251 | static struct attribute *l2_ctl_sysfs_attrs[] = { | |
252 | &l2_ctl_attr_l2_ws_latency.dev_attr.attr, | |
253 | &l2_ctl_attr_l2_tag_latency.dev_attr.attr, | |
254 | &l2_ctl_attr_l2_data_latency.dev_attr.attr, | |
255 | NULL | |
256 | }; | |
257 | ATTRIBUTE_GROUPS(l2_ctl_sysfs); | |
258 | ||
259 | static void l2_ctl_remove_sysfs(void *data) | |
260 | { | |
261 | struct l2_ctl *l2 = data; | |
262 | ||
263 | device_remove_groups(l2->dev, l2_ctl_sysfs_groups); | |
264 | } | |
265 | ||
266 | static int l2_ctl_init_sysfs(struct l2_ctl *l2) | |
267 | { | |
268 | int ret; | |
269 | ||
270 | ret = device_add_groups(l2->dev, l2_ctl_sysfs_groups); | |
271 | if (ret) { | |
272 | dev_err(l2->dev, "Failed to create L2 CTL sysfs nodes\n"); | |
273 | return ret; | |
274 | } | |
275 | ||
276 | ret = devm_add_action_or_reset(l2->dev, l2_ctl_remove_sysfs, l2); | |
277 | if (ret) | |
278 | dev_err(l2->dev, "Can't add L2 CTL sysfs remove action\n"); | |
279 | ||
280 | return ret; | |
281 | } | |
282 | ||
283 | static int l2_ctl_probe(struct platform_device *pdev) | |
284 | { | |
285 | struct l2_ctl *l2; | |
286 | int ret; | |
287 | ||
288 | l2 = l2_ctl_create_data(pdev); | |
289 | if (IS_ERR(l2)) | |
290 | return PTR_ERR(l2); | |
291 | ||
292 | ret = l2_ctl_find_sys_regs(l2); | |
293 | if (ret) | |
294 | return ret; | |
295 | ||
296 | ret = l2_ctl_of_parse(l2); | |
297 | if (ret) | |
298 | return ret; | |
299 | ||
300 | ret = l2_ctl_init_sysfs(l2); | |
301 | if (ret) | |
302 | return ret; | |
303 | ||
304 | return 0; | |
305 | } | |
306 | ||
307 | static const struct of_device_id l2_ctl_of_match[] = { | |
308 | { .compatible = "baikal,bt1-l2-ctl" }, | |
309 | { } | |
310 | }; | |
311 | MODULE_DEVICE_TABLE(of, l2_ctl_of_match); | |
312 | ||
313 | static struct platform_driver l2_ctl_driver = { | |
314 | .probe = l2_ctl_probe, | |
315 | .driver = { | |
316 | .name = "bt1-l2-ctl", | |
317 | .of_match_table = l2_ctl_of_match | |
318 | } | |
319 | }; | |
320 | module_platform_driver(l2_ctl_driver); | |
321 | ||
322 | MODULE_AUTHOR("Serge Semin <Sergey.Semin@baikalelectronics.ru>"); | |
323 | MODULE_DESCRIPTION("Baikal-T1 L2-cache driver"); | |
324 | MODULE_LICENSE("GPL v2"); |