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 | }; |
69 | |
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(map: l2->sys_regs, L2_CTL_REG, val: &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(map: l2->sys_regs, L2_CTL_REG, mask, val: 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, size: sizeof(*l2), GFP_KERNEL); |
155 | if (!l2) |
156 | return ERR_PTR(error: -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(error: ret); |
162 | } |
163 | |
164 | l2->dev = dev; |
165 | platform_set_drvdata(pdev, data: 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(np: l2->dev->of_node->parent); |
173 | if (IS_ERR(ptr: l2->sys_regs)) { |
174 | dev_err(l2->dev, "Couldn't get L2 CTL register map\n" ); |
175 | return PTR_ERR(ptr: 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(np: l2->dev->of_node, propname, out_value: &data)) { |
188 | ret = l2_ctl_set_latency(l2, id, val: 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, id: L2_WS_STALL, propname: "baikal,l2-ws-latency" ); |
201 | if (ret) |
202 | return ret; |
203 | |
204 | ret = l2_ctl_of_parse_property(l2, id: L2_TAG_STALL, propname: "baikal,l2-tag-latency" ); |
205 | if (ret) |
206 | return ret; |
207 | |
208 | return l2_ctl_of_parse_property(l2, id: L2_DATA_STALL, |
209 | propname: "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, id: devattr->id, val: &data); |
222 | if (ret) |
223 | return ret; |
224 | |
225 | return scnprintf(buf, PAGE_SIZE, fmt: "%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(s: buf, base: 0, res: &data) < 0) |
238 | return -EINVAL; |
239 | |
240 | ret = l2_ctl_set_latency(l2, id: devattr->id, val: data); |
241 | if (ret) |
242 | return ret; |
243 | |
244 | return count; |
245 | } |
246 | |
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(dev: l2->dev, groups: 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(dev: l2->dev, groups: 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(ptr: l2)) |
290 | return PTR_ERR(ptr: 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 | |