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
27struct 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
38static struct ti_emif_data *emif_instance;
39
40static 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
47static 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
54static 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
63static 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
143err_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
149static 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 */
183static 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 */
201int 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}
216EXPORT_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 */
223int 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}
236EXPORT_SYMBOL_GPL(ti_emif_get_mem_type);
237
238static 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};
245MODULE_DEVICE_TABLE(of, ti_emif_of_match);
246
247#ifdef CONFIG_PM_SLEEP
248static 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
265static 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
275static 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
312fail_free_sram:
313	ti_emif_free_sram(emif_data);
314
315	return ret;
316}
317
318static void 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
327static const struct dev_pm_ops ti_emif_pm_ops = {
328	SET_SYSTEM_SLEEP_PM_OPS(ti_emif_suspend, ti_emif_resume)
329};
330
331static struct platform_driver ti_emif_driver = {
332	.probe = ti_emif_probe,
333	.remove_new = ti_emif_remove,
334	.driver = {
335		.name = KBUILD_MODNAME,
336		.of_match_table = ti_emif_of_match,
337		.pm = &ti_emif_pm_ops,
338	},
339};
340module_platform_driver(ti_emif_driver);
341
342MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
343MODULE_DESCRIPTION("Texas Instruments SRAM EMIF driver");
344MODULE_LICENSE("GPL v2");
345