1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * TI AM33XX SRAM EMIF Driver
4 *
5 * Copyright (C) 2016-2017 Texas Instruments Inc.
6 * Dave Gerlach
7 */
8
9 #include <linux/err.h>
10 #include <linux/genalloc.h>
11 #include <linux/io.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/of_platform.h>
16 #include <linux/platform_device.h>
17 #include <linux/sram.h>
18 #include <linux/ti-emif-sram.h>
19
20 #include "emif.h"
21
22 #define TI_EMIF_SRAM_SYMBOL_OFFSET(sym) ((unsigned long)(sym) - \
23 (unsigned long)&ti_emif_sram)
24
25 #define EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES 0x00a0
26
27 struct ti_emif_data {
28 phys_addr_t ti_emif_sram_phys;
29 phys_addr_t ti_emif_sram_data_phys;
30 unsigned long ti_emif_sram_virt;
31 unsigned long ti_emif_sram_data_virt;
32 struct gen_pool *sram_pool_code;
33 struct gen_pool *sram_pool_data;
34 struct ti_emif_pm_data pm_data;
35 struct ti_emif_pm_functions pm_functions;
36 };
37
38 static struct ti_emif_data *emif_instance;
39
sram_suspend_address(struct ti_emif_data * emif_data,unsigned long addr)40 static u32 sram_suspend_address(struct ti_emif_data *emif_data,
41 unsigned long addr)
42 {
43 return (emif_data->ti_emif_sram_virt +
44 TI_EMIF_SRAM_SYMBOL_OFFSET(addr));
45 }
46
sram_resume_address(struct ti_emif_data * emif_data,unsigned long addr)47 static phys_addr_t sram_resume_address(struct ti_emif_data *emif_data,
48 unsigned long addr)
49 {
50 return ((unsigned long)emif_data->ti_emif_sram_phys +
51 TI_EMIF_SRAM_SYMBOL_OFFSET(addr));
52 }
53
ti_emif_free_sram(struct ti_emif_data * emif_data)54 static void ti_emif_free_sram(struct ti_emif_data *emif_data)
55 {
56 gen_pool_free(emif_data->sram_pool_code, emif_data->ti_emif_sram_virt,
57 ti_emif_sram_sz);
58 gen_pool_free(emif_data->sram_pool_data,
59 emif_data->ti_emif_sram_data_virt,
60 sizeof(struct emif_regs_amx3));
61 }
62
ti_emif_alloc_sram(struct device * dev,struct ti_emif_data * emif_data)63 static int ti_emif_alloc_sram(struct device *dev,
64 struct ti_emif_data *emif_data)
65 {
66 struct device_node *np = dev->of_node;
67 int ret;
68
69 emif_data->sram_pool_code = of_gen_pool_get(np, "sram", 0);
70 if (!emif_data->sram_pool_code) {
71 dev_err(dev, "Unable to get sram pool for ocmcram code\n");
72 return -ENODEV;
73 }
74
75 emif_data->ti_emif_sram_virt =
76 gen_pool_alloc(emif_data->sram_pool_code,
77 ti_emif_sram_sz);
78 if (!emif_data->ti_emif_sram_virt) {
79 dev_err(dev, "Unable to allocate code memory from ocmcram\n");
80 return -ENOMEM;
81 }
82
83 /* Save physical address to calculate resume offset during pm init */
84 emif_data->ti_emif_sram_phys =
85 gen_pool_virt_to_phys(emif_data->sram_pool_code,
86 emif_data->ti_emif_sram_virt);
87
88 /* Get sram pool for data section and allocate space */
89 emif_data->sram_pool_data = of_gen_pool_get(np, "sram", 1);
90 if (!emif_data->sram_pool_data) {
91 dev_err(dev, "Unable to get sram pool for ocmcram data\n");
92 ret = -ENODEV;
93 goto err_free_sram_code;
94 }
95
96 emif_data->ti_emif_sram_data_virt =
97 gen_pool_alloc(emif_data->sram_pool_data,
98 sizeof(struct emif_regs_amx3));
99 if (!emif_data->ti_emif_sram_data_virt) {
100 dev_err(dev, "Unable to allocate data memory from ocmcram\n");
101 ret = -ENOMEM;
102 goto err_free_sram_code;
103 }
104
105 /* Save physical address to calculate resume offset during pm init */
106 emif_data->ti_emif_sram_data_phys =
107 gen_pool_virt_to_phys(emif_data->sram_pool_data,
108 emif_data->ti_emif_sram_data_virt);
109 /*
110 * These functions are called during suspend path while MMU is
111 * still on so add virtual base to offset for absolute address
112 */
113 emif_data->pm_functions.save_context =
114 sram_suspend_address(emif_data,
115 (unsigned long)ti_emif_save_context);
116 emif_data->pm_functions.enter_sr =
117 sram_suspend_address(emif_data,
118 (unsigned long)ti_emif_enter_sr);
119 emif_data->pm_functions.abort_sr =
120 sram_suspend_address(emif_data,
121 (unsigned long)ti_emif_abort_sr);
122
123 /*
124 * These are called during resume path when MMU is not enabled
125 * so physical address is used instead
126 */
127 emif_data->pm_functions.restore_context =
128 sram_resume_address(emif_data,
129 (unsigned long)ti_emif_restore_context);
130 emif_data->pm_functions.exit_sr =
131 sram_resume_address(emif_data,
132 (unsigned long)ti_emif_exit_sr);
133 emif_data->pm_functions.run_hw_leveling =
134 sram_resume_address(emif_data,
135 (unsigned long)ti_emif_run_hw_leveling);
136
137 emif_data->pm_data.regs_virt =
138 (struct emif_regs_amx3 *)emif_data->ti_emif_sram_data_virt;
139 emif_data->pm_data.regs_phys = emif_data->ti_emif_sram_data_phys;
140
141 return 0;
142
143 err_free_sram_code:
144 gen_pool_free(emif_data->sram_pool_code, emif_data->ti_emif_sram_virt,
145 ti_emif_sram_sz);
146 return ret;
147 }
148
ti_emif_push_sram(struct device * dev,struct ti_emif_data * emif_data)149 static int ti_emif_push_sram(struct device *dev, struct ti_emif_data *emif_data)
150 {
151 void *copy_addr;
152 u32 data_addr;
153
154 copy_addr = sram_exec_copy(emif_data->sram_pool_code,
155 (void *)emif_data->ti_emif_sram_virt,
156 &ti_emif_sram, ti_emif_sram_sz);
157 if (!copy_addr) {
158 dev_err(dev, "Cannot copy emif code to sram\n");
159 return -ENODEV;
160 }
161
162 data_addr = sram_suspend_address(emif_data,
163 (unsigned long)&ti_emif_pm_sram_data);
164 copy_addr = sram_exec_copy(emif_data->sram_pool_code,
165 (void *)data_addr,
166 &emif_data->pm_data,
167 sizeof(emif_data->pm_data));
168 if (!copy_addr) {
169 dev_err(dev, "Cannot copy emif data to code sram\n");
170 return -ENODEV;
171 }
172
173 return 0;
174 }
175
176 /*
177 * Due to Usage Note 3.1.2 "DDR3: JEDEC Compliance for Maximum
178 * Self-Refresh Command Limit" found in AM335x Silicon Errata
179 * (Document SPRZ360F Revised November 2013) we must configure
180 * the self refresh delay timer to 0xA (8192 cycles) to avoid
181 * generating too many refresh command from the EMIF.
182 */
ti_emif_configure_sr_delay(struct ti_emif_data * emif_data)183 static void ti_emif_configure_sr_delay(struct ti_emif_data *emif_data)
184 {
185 writel(EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES,
186 (emif_data->pm_data.ti_emif_base_addr_virt +
187 EMIF_POWER_MANAGEMENT_CONTROL));
188
189 writel(EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES,
190 (emif_data->pm_data.ti_emif_base_addr_virt +
191 EMIF_POWER_MANAGEMENT_CTRL_SHDW));
192 }
193
194 /**
195 * ti_emif_copy_pm_function_table - copy mapping of pm funcs in sram
196 * @sram_pool: pointer to struct gen_pool where dst resides
197 * @dst: void * to address that table should be copied
198 *
199 * Returns 0 if success other error code if table is not available
200 */
ti_emif_copy_pm_function_table(struct gen_pool * sram_pool,void * dst)201 int ti_emif_copy_pm_function_table(struct gen_pool *sram_pool, void *dst)
202 {
203 void *copy_addr;
204
205 if (!emif_instance)
206 return -ENODEV;
207
208 copy_addr = sram_exec_copy(sram_pool, dst,
209 &emif_instance->pm_functions,
210 sizeof(emif_instance->pm_functions));
211 if (!copy_addr)
212 return -ENODEV;
213
214 return 0;
215 }
216 EXPORT_SYMBOL_GPL(ti_emif_copy_pm_function_table);
217
218 /**
219 * ti_emif_get_mem_type - return type for memory type in use
220 *
221 * Returns memory type value read from EMIF or error code if fails
222 */
ti_emif_get_mem_type(void)223 int ti_emif_get_mem_type(void)
224 {
225 unsigned long temp;
226
227 if (!emif_instance)
228 return -ENODEV;
229
230 temp = readl(emif_instance->pm_data.ti_emif_base_addr_virt +
231 EMIF_SDRAM_CONFIG);
232
233 temp = (temp & SDRAM_TYPE_MASK) >> SDRAM_TYPE_SHIFT;
234 return temp;
235 }
236 EXPORT_SYMBOL_GPL(ti_emif_get_mem_type);
237
238 static const struct of_device_id ti_emif_of_match[] = {
239 { .compatible = "ti,emif-am3352", .data =
240 (void *)EMIF_SRAM_AM33_REG_LAYOUT, },
241 { .compatible = "ti,emif-am4372", .data =
242 (void *)EMIF_SRAM_AM43_REG_LAYOUT, },
243 {},
244 };
245 MODULE_DEVICE_TABLE(of, ti_emif_of_match);
246
247 #ifdef CONFIG_PM_SLEEP
ti_emif_resume(struct device * dev)248 static int ti_emif_resume(struct device *dev)
249 {
250 unsigned long tmp =
251 __raw_readl((void __iomem *)emif_instance->ti_emif_sram_virt);
252
253 /*
254 * Check to see if what we are copying is already present in the
255 * first byte at the destination, only copy if it is not which
256 * indicates we have lost context and sram no longer contains
257 * the PM code
258 */
259 if (tmp != ti_emif_sram)
260 ti_emif_push_sram(dev, emif_instance);
261
262 return 0;
263 }
264
ti_emif_suspend(struct device * dev)265 static int ti_emif_suspend(struct device *dev)
266 {
267 /*
268 * The contents will be present in DDR hence no need to
269 * explicitly save
270 */
271 return 0;
272 }
273 #endif /* CONFIG_PM_SLEEP */
274
ti_emif_probe(struct platform_device * pdev)275 static int ti_emif_probe(struct platform_device *pdev)
276 {
277 int ret;
278 struct resource *res;
279 struct device *dev = &pdev->dev;
280 struct ti_emif_data *emif_data;
281
282 emif_data = devm_kzalloc(dev, sizeof(*emif_data), GFP_KERNEL);
283 if (!emif_data)
284 return -ENOMEM;
285
286 emif_data->pm_data.ti_emif_sram_config = (unsigned long) device_get_match_data(&pdev->dev);
287
288 emif_data->pm_data.ti_emif_base_addr_virt = devm_platform_get_and_ioremap_resource(pdev,
289 0,
290 &res);
291 if (IS_ERR(emif_data->pm_data.ti_emif_base_addr_virt)) {
292 ret = PTR_ERR(emif_data->pm_data.ti_emif_base_addr_virt);
293 return ret;
294 }
295
296 emif_data->pm_data.ti_emif_base_addr_phys = res->start;
297
298 ti_emif_configure_sr_delay(emif_data);
299
300 ret = ti_emif_alloc_sram(dev, emif_data);
301 if (ret)
302 return ret;
303
304 ret = ti_emif_push_sram(dev, emif_data);
305 if (ret)
306 goto fail_free_sram;
307
308 emif_instance = emif_data;
309
310 return 0;
311
312 fail_free_sram:
313 ti_emif_free_sram(emif_data);
314
315 return ret;
316 }
317
ti_emif_remove(struct platform_device * pdev)318 static int ti_emif_remove(struct platform_device *pdev)
319 {
320 struct ti_emif_data *emif_data = emif_instance;
321
322 emif_instance = NULL;
323
324 ti_emif_free_sram(emif_data);
325
326 return 0;
327 }
328
329 static const struct dev_pm_ops ti_emif_pm_ops = {
330 SET_SYSTEM_SLEEP_PM_OPS(ti_emif_suspend, ti_emif_resume)
331 };
332
333 static struct platform_driver ti_emif_driver = {
334 .probe = ti_emif_probe,
335 .remove = ti_emif_remove,
336 .driver = {
337 .name = KBUILD_MODNAME,
338 .of_match_table = ti_emif_of_match,
339 .pm = &ti_emif_pm_ops,
340 },
341 };
342 module_platform_driver(ti_emif_driver);
343
344 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
345 MODULE_DESCRIPTION("Texas Instruments SRAM EMIF driver");
346 MODULE_LICENSE("GPL v2");
347