1/*
  2 * TI AM33XX SRAM EMIF Driver
  3 *
  4 * Copyright (C) 2016-2017 Texas Instruments Inc.
  5 *	Dave Gerlach
  6 *
  7 * This program is free software; you can redistribute it and/or
  8 * modify it under the terms of the GNU General Public License
  9 * version 2 as published by the Free Software Foundation.
 10 *
 11 * This program is distributed in the hope that it will be useful,
 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14 * GNU General Public License for more details.
 15 */
 16
 17#include <linux/err.h>
 18#include <linux/genalloc.h>
 19#include <linux/io.h>
 20#include <linux/kernel.h>
 21#include <linux/module.h>
 22#include <linux/of.h>
 23#include <linux/of_platform.h>
 24#include <linux/platform_device.h>
 25#include <linux/sram.h>
 26#include <linux/ti-emif-sram.h>
 27
 28#include "emif.h"
 29
 30#define TI_EMIF_SRAM_SYMBOL_OFFSET(sym) ((unsigned long)(sym) - \
 31					 (unsigned long)&ti_emif_sram)
 32
 33#define EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES		0x00a0
 34
 35struct ti_emif_data {
 36	phys_addr_t ti_emif_sram_phys;
 37	phys_addr_t ti_emif_sram_data_phys;
 38	unsigned long ti_emif_sram_virt;
 39	unsigned long ti_emif_sram_data_virt;
 40	struct gen_pool *sram_pool_code;
 41	struct gen_pool	*sram_pool_data;
 42	struct ti_emif_pm_data pm_data;
 43	struct ti_emif_pm_functions pm_functions;
 44};
 45
 46static struct ti_emif_data *emif_instance;
 47
 48static u32 sram_suspend_address(struct ti_emif_data *emif_data,
 49				unsigned long addr)
 50{
 51	return (emif_data->ti_emif_sram_virt +
 52		TI_EMIF_SRAM_SYMBOL_OFFSET(addr));
 53}
 54
 55static phys_addr_t sram_resume_address(struct ti_emif_data *emif_data,
 56				       unsigned long addr)
 57{
 58	return ((unsigned long)emif_data->ti_emif_sram_phys +
 59		TI_EMIF_SRAM_SYMBOL_OFFSET(addr));
 60}
 61
 62static void ti_emif_free_sram(struct ti_emif_data *emif_data)
 63{
 64	gen_pool_free(emif_data->sram_pool_code, emif_data->ti_emif_sram_virt,
 65		      ti_emif_sram_sz);
 66	gen_pool_free(emif_data->sram_pool_data,
 67		      emif_data->ti_emif_sram_data_virt,
 68		      sizeof(struct emif_regs_amx3));
 69}
 70
 71static int ti_emif_alloc_sram(struct device *dev,
 72			      struct ti_emif_data *emif_data)
 73{
 74	struct device_node *np = dev->of_node;
 75	int ret;
 76
 77	emif_data->sram_pool_code = of_gen_pool_get(np, "sram", 0);
 78	if (!emif_data->sram_pool_code) {
 79		dev_err(dev, "Unable to get sram pool for ocmcram code\n");
 80		return -ENODEV;
 81	}
 82
 83	emif_data->ti_emif_sram_virt =
 84			gen_pool_alloc(emif_data->sram_pool_code,
 85				       ti_emif_sram_sz);
 86	if (!emif_data->ti_emif_sram_virt) {
 87		dev_err(dev, "Unable to allocate code memory from ocmcram\n");
 88		return -ENOMEM;
 89	}
 90
 91	/* Save physical address to calculate resume offset during pm init */
 92	emif_data->ti_emif_sram_phys =
 93			gen_pool_virt_to_phys(emif_data->sram_pool_code,
 94					      emif_data->ti_emif_sram_virt);
 95
 96	/* Get sram pool for data section and allocate space */
 97	emif_data->sram_pool_data = of_gen_pool_get(np, "sram", 1);
 98	if (!emif_data->sram_pool_data) {
 99		dev_err(dev, "Unable to get sram pool for ocmcram data\n");
100		ret = -ENODEV;
101		goto err_free_sram_code;
102	}
103
104	emif_data->ti_emif_sram_data_virt =
105				gen_pool_alloc(emif_data->sram_pool_data,
106					       sizeof(struct emif_regs_amx3));
107	if (!emif_data->ti_emif_sram_data_virt) {
108		dev_err(dev, "Unable to allocate data memory from ocmcram\n");
109		ret = -ENOMEM;
110		goto err_free_sram_code;
111	}
112
113	/* Save physical address to calculate resume offset during pm init */
114	emif_data->ti_emif_sram_data_phys =
115		gen_pool_virt_to_phys(emif_data->sram_pool_data,
116				      emif_data->ti_emif_sram_data_virt);
117	/*
118	 * These functions are called during suspend path while MMU is
119	 * still on so add virtual base to offset for absolute address
120	 */
121	emif_data->pm_functions.save_context =
122		sram_suspend_address(emif_data,
123				     (unsigned long)ti_emif_save_context);
124	emif_data->pm_functions.enter_sr =
125		sram_suspend_address(emif_data,
126				     (unsigned long)ti_emif_enter_sr);
127	emif_data->pm_functions.abort_sr =
128		sram_suspend_address(emif_data,
129				     (unsigned long)ti_emif_abort_sr);
130
131	/*
132	 * These are called during resume path when MMU is not enabled
133	 * so physical address is used instead
134	 */
135	emif_data->pm_functions.restore_context =
136		sram_resume_address(emif_data,
137				    (unsigned long)ti_emif_restore_context);
138	emif_data->pm_functions.exit_sr =
139		sram_resume_address(emif_data,
140				    (unsigned long)ti_emif_exit_sr);
141
142	emif_data->pm_data.regs_virt =
143		(struct emif_regs_amx3 *)emif_data->ti_emif_sram_data_virt;
144	emif_data->pm_data.regs_phys = emif_data->ti_emif_sram_data_phys;
145
146	return 0;
147
148err_free_sram_code:
149	gen_pool_free(emif_data->sram_pool_code, emif_data->ti_emif_sram_virt,
150		      ti_emif_sram_sz);
151	return ret;
152}
153
154static int ti_emif_push_sram(struct device *dev, struct ti_emif_data *emif_data)
155{
156	void *copy_addr;
157	u32 data_addr;
158
159	copy_addr = sram_exec_copy(emif_data->sram_pool_code,
160				   (void *)emif_data->ti_emif_sram_virt,
161				   &ti_emif_sram, ti_emif_sram_sz);
162	if (!copy_addr) {
163		dev_err(dev, "Cannot copy emif code to sram\n");
164		return -ENODEV;
165	}
166
167	data_addr = sram_suspend_address(emif_data,
168					 (unsigned long)&ti_emif_pm_sram_data);
169	copy_addr = sram_exec_copy(emif_data->sram_pool_code,
170				   (void *)data_addr,
171				   &emif_data->pm_data,
172				   sizeof(emif_data->pm_data));
173	if (!copy_addr) {
174		dev_err(dev, "Cannot copy emif data to code sram\n");
175		return -ENODEV;
176	}
177
178	return 0;
179}
180
181/*
182 * Due to Usage Note 3.1.2 "DDR3: JEDEC Compliance for Maximum
183 * Self-Refresh Command Limit" found in AM335x Silicon Errata
184 * (Document SPRZ360F Revised November 2013) we must configure
185 * the self refresh delay timer to 0xA (8192 cycles) to avoid
186 * generating too many refresh command from the EMIF.
187 */
188static void ti_emif_configure_sr_delay(struct ti_emif_data *emif_data)
189{
190	writel(EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES,
191	       (emif_data->pm_data.ti_emif_base_addr_virt +
192		EMIF_POWER_MANAGEMENT_CONTROL));
193
194	writel(EMIF_POWER_MGMT_WAIT_SELF_REFRESH_8192_CYCLES,
195	       (emif_data->pm_data.ti_emif_base_addr_virt +
196		EMIF_POWER_MANAGEMENT_CTRL_SHDW));
197}
198
199/**
200 * ti_emif_copy_pm_function_table - copy mapping of pm funcs in sram
201 * @sram_pool: pointer to struct gen_pool where dst resides
202 * @dst: void * to address that table should be copied
203 *
204 * Returns 0 if success other error code if table is not available
205 */
206int ti_emif_copy_pm_function_table(struct gen_pool *sram_pool, void *dst)
207{
208	void *copy_addr;
209
210	if (!emif_instance)
211		return -ENODEV;
212
213	copy_addr = sram_exec_copy(sram_pool, dst,
214				   &emif_instance->pm_functions,
215				   sizeof(emif_instance->pm_functions));
216	if (!copy_addr)
217		return -ENODEV;
218
219	return 0;
220}
221EXPORT_SYMBOL_GPL(ti_emif_copy_pm_function_table);
222
223/**
224 * ti_emif_get_mem_type - return type for memory type in use
225 *
226 * Returns memory type value read from EMIF or error code if fails
227 */
228int ti_emif_get_mem_type(void)
229{
230	unsigned long temp;
231
232	if (!emif_instance)
233		return -ENODEV;
234
235	temp = readl(emif_instance->pm_data.ti_emif_base_addr_virt +
236		     EMIF_SDRAM_CONFIG);
237
238	temp = (temp & SDRAM_TYPE_MASK) >> SDRAM_TYPE_SHIFT;
239	return temp;
240}
241EXPORT_SYMBOL_GPL(ti_emif_get_mem_type);
242
243static const struct of_device_id ti_emif_of_match[] = {
244	{ .compatible = "ti,emif-am3352", .data =
245					(void *)EMIF_SRAM_AM33_REG_LAYOUT, },
246	{ .compatible = "ti,emif-am4372", .data =
247					(void *)EMIF_SRAM_AM43_REG_LAYOUT, },
248	{},
249};
250MODULE_DEVICE_TABLE(of, ti_emif_of_match);
251
252static int ti_emif_probe(struct platform_device *pdev)
253{
254	int ret;
255	struct resource *res;
256	struct device *dev = &pdev->dev;
257	const struct of_device_id *match;
258	struct ti_emif_data *emif_data;
259
260	emif_data = devm_kzalloc(dev, sizeof(*emif_data), GFP_KERNEL);
261	if (!emif_data)
262		return -ENOMEM;
263
264	match = of_match_device(ti_emif_of_match, &pdev->dev);
265	if (!match)
266		return -ENODEV;
267
268	emif_data->pm_data.ti_emif_sram_config = (unsigned long)match->data;
269
270	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
271	emif_data->pm_data.ti_emif_base_addr_virt = devm_ioremap_resource(dev,
272									  res);
273	if (IS_ERR(emif_data->pm_data.ti_emif_base_addr_virt)) {
274		ret = PTR_ERR(emif_data->pm_data.ti_emif_base_addr_virt);
275		return ret;
276	}
277
278	emif_data->pm_data.ti_emif_base_addr_phys = res->start;
279
280	ti_emif_configure_sr_delay(emif_data);
281
282	ret = ti_emif_alloc_sram(dev, emif_data);
283	if (ret)
284		return ret;
285
286	ret = ti_emif_push_sram(dev, emif_data);
287	if (ret)
288		goto fail_free_sram;
289
290	emif_instance = emif_data;
291
292	return 0;
293
294fail_free_sram:
295	ti_emif_free_sram(emif_data);
296
297	return ret;
298}
299
300static int ti_emif_remove(struct platform_device *pdev)
301{
302	struct ti_emif_data *emif_data = emif_instance;
303
304	emif_instance = NULL;
305
306	ti_emif_free_sram(emif_data);
307
308	return 0;
309}
310
311static struct platform_driver ti_emif_driver = {
312	.probe = ti_emif_probe,
313	.remove = ti_emif_remove,
314	.driver = {
315		.name = KBUILD_MODNAME,
316		.of_match_table = of_match_ptr(ti_emif_of_match),
317	},
318};
319module_platform_driver(ti_emif_driver);
320
321MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
322MODULE_DESCRIPTION("Texas Instruments SRAM EMIF driver");
323MODULE_LICENSE("GPL v2");