1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * System Control Driver
  4 *
  5 * Copyright (C) 2012 Freescale Semiconductor, Inc.
  6 * Copyright (C) 2012 Linaro Ltd.
  7 *
  8 * Author: Dong Aisheng <dong.aisheng@linaro.org>
 
 
 
 
 
  9 */
 10
 11#include <linux/clk.h>
 12#include <linux/err.h>
 13#include <linux/hwspinlock.h>
 14#include <linux/io.h>
 15#include <linux/init.h>
 16#include <linux/list.h>
 17#include <linux/of.h>
 18#include <linux/of_address.h>
 19#include <linux/of_platform.h>
 20#include <linux/platform_data/syscon.h>
 21#include <linux/platform_device.h>
 22#include <linux/regmap.h>
 23#include <linux/reset.h>
 24#include <linux/mfd/syscon.h>
 25#include <linux/slab.h>
 26
 27static struct platform_driver syscon_driver;
 28
 29static DEFINE_SPINLOCK(syscon_list_slock);
 30static LIST_HEAD(syscon_list);
 31
 32struct syscon {
 33	struct device_node *np;
 34	struct regmap *regmap;
 35	struct reset_control *reset;
 36	struct list_head list;
 37};
 38
 39static const struct regmap_config syscon_regmap_config = {
 40	.reg_bits = 32,
 41	.val_bits = 32,
 42	.reg_stride = 4,
 43};
 44
 45static struct syscon *of_syscon_register(struct device_node *np, bool check_res)
 46{
 47	struct clk *clk;
 48	struct syscon *syscon;
 49	struct regmap *regmap;
 50	void __iomem *base;
 51	u32 reg_io_width;
 52	int ret;
 53	struct regmap_config syscon_config = syscon_regmap_config;
 54	struct resource res;
 55	struct reset_control *reset;
 
 
 56
 57	syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
 58	if (!syscon)
 59		return ERR_PTR(-ENOMEM);
 60
 61	if (of_address_to_resource(np, 0, &res)) {
 62		ret = -ENOMEM;
 63		goto err_map;
 64	}
 65
 66	base = of_iomap(np, 0);
 67	if (!base) {
 68		ret = -ENOMEM;
 69		goto err_map;
 70	}
 71
 72	/* Parse the device's DT node for an endianness specification */
 73	if (of_property_read_bool(np, "big-endian"))
 74		syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
 75	else if (of_property_read_bool(np, "little-endian"))
 76		syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
 77	else if (of_property_read_bool(np, "native-endian"))
 78		syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
 79
 80	/*
 81	 * search for reg-io-width property in DT. If it is not provided,
 82	 * default to 4 bytes. regmap_init_mmio will return an error if values
 83	 * are invalid so there is no need to check them here.
 84	 */
 85	ret = of_property_read_u32(np, "reg-io-width", &reg_io_width);
 86	if (ret)
 87		reg_io_width = 4;
 88
 89	ret = of_hwspin_lock_get_id(np, 0);
 90	if (ret > 0 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
 91		syscon_config.use_hwlock = true;
 92		syscon_config.hwlock_id = ret;
 93		syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
 94	} else if (ret < 0) {
 95		switch (ret) {
 96		case -ENOENT:
 97			/* Ignore missing hwlock, it's optional. */
 98			break;
 99		default:
100			pr_err("Failed to retrieve valid hwlock: %d\n", ret);
101			fallthrough;
102		case -EPROBE_DEFER:
103			goto err_regmap;
104		}
105	}
106
107	syscon_config.name = kasprintf(GFP_KERNEL, "%pOFn@%pa", np, &res.start);
108	if (!syscon_config.name) {
109		ret = -ENOMEM;
110		goto err_regmap;
111	}
112	syscon_config.reg_stride = reg_io_width;
113	syscon_config.val_bits = reg_io_width * 8;
114	syscon_config.max_register = resource_size(&res) - reg_io_width;
115
116	regmap = regmap_init_mmio(NULL, base, &syscon_config);
117	kfree(syscon_config.name);
118	if (IS_ERR(regmap)) {
119		pr_err("regmap init failed\n");
120		ret = PTR_ERR(regmap);
121		goto err_regmap;
122	}
123
124	if (check_res) {
125		clk = of_clk_get(np, 0);
126		if (IS_ERR(clk)) {
127			ret = PTR_ERR(clk);
128			/* clock is optional */
129			if (ret != -ENOENT)
130				goto err_clk;
131		} else {
132			ret = regmap_mmio_attach_clk(regmap, clk);
133			if (ret)
134				goto err_attach_clk;
135		}
136
137		reset = of_reset_control_get_optional_exclusive(np, NULL);
138		if (IS_ERR(reset)) {
139			ret = PTR_ERR(reset);
140			goto err_attach_clk;
141		}
142
143		ret = reset_control_deassert(reset);
144		if (ret)
145			goto err_reset;
146	}
147
148	syscon->regmap = regmap;
149	syscon->np = np;
150
151	spin_lock(&syscon_list_slock);
152	list_add_tail(&syscon->list, &syscon_list);
153	spin_unlock(&syscon_list_slock);
154
155	return syscon;
156
157err_reset:
158	reset_control_put(reset);
159err_attach_clk:
160	if (!IS_ERR(clk))
161		clk_put(clk);
162err_clk:
163	regmap_exit(regmap);
164err_regmap:
165	iounmap(base);
166err_map:
167	kfree(syscon);
168	return ERR_PTR(ret);
169}
170
171static struct regmap *device_node_get_regmap(struct device_node *np,
172					     bool check_res)
173{
174	struct syscon *entry, *syscon = NULL;
175
176	spin_lock(&syscon_list_slock);
177
178	list_for_each_entry(entry, &syscon_list, list)
179		if (entry->np == np) {
180			syscon = entry;
181			break;
182		}
183
184	spin_unlock(&syscon_list_slock);
185
186	if (!syscon)
187		syscon = of_syscon_register(np, check_res);
188
189	if (IS_ERR(syscon))
190		return ERR_CAST(syscon);
191
192	return syscon->regmap;
193}
194
195struct regmap *device_node_to_regmap(struct device_node *np)
196{
197	return device_node_get_regmap(np, false);
198}
199EXPORT_SYMBOL_GPL(device_node_to_regmap);
200
201struct regmap *syscon_node_to_regmap(struct device_node *np)
202{
203	if (!of_device_is_compatible(np, "syscon"))
204		return ERR_PTR(-EINVAL);
205
206	return device_node_get_regmap(np, true);
207}
208EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
209
210struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
211{
212	struct device_node *syscon_np;
213	struct regmap *regmap;
214
215	syscon_np = of_find_compatible_node(NULL, NULL, s);
216	if (!syscon_np)
217		return ERR_PTR(-ENODEV);
218
219	regmap = syscon_node_to_regmap(syscon_np);
220	of_node_put(syscon_np);
221
222	return regmap;
223}
224EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
225
226struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
227					const char *property)
228{
229	struct device_node *syscon_np;
230	struct regmap *regmap;
231
232	if (property)
233		syscon_np = of_parse_phandle(np, property, 0);
234	else
235		syscon_np = np;
236
237	if (!syscon_np)
238		return ERR_PTR(-ENODEV);
 
 
239
240	regmap = syscon_node_to_regmap(syscon_np);
241	of_node_put(syscon_np);
242
243	return regmap;
244}
245EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
246
247struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np,
248					const char *property,
249					int arg_count,
250					unsigned int *out_args)
251{
252	struct device_node *syscon_np;
253	struct of_phandle_args args;
254	struct regmap *regmap;
255	unsigned int index;
256	int rc;
257
258	rc = of_parse_phandle_with_fixed_args(np, property, arg_count,
259			0, &args);
260	if (rc)
261		return ERR_PTR(rc);
262
263	syscon_np = args.np;
264	if (!syscon_np)
265		return ERR_PTR(-ENODEV);
266
267	regmap = syscon_node_to_regmap(syscon_np);
268	for (index = 0; index < arg_count; index++)
269		out_args[index] = args.args[index];
270	of_node_put(syscon_np);
271
272	return regmap;
273}
274EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_args);
275
276/*
277 * It behaves the same as syscon_regmap_lookup_by_phandle() except where
278 * there is no regmap phandle. In this case, instead of returning -ENODEV,
279 * the function returns NULL.
280 */
281struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np,
282					const char *property)
283{
284	struct regmap *regmap;
285
286	regmap = syscon_regmap_lookup_by_phandle(np, property);
287	if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
288		return NULL;
289
290	return regmap;
291}
292EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_optional);
293
294static int syscon_probe(struct platform_device *pdev)
295{
296	struct device *dev = &pdev->dev;
297	struct syscon_platform_data *pdata = dev_get_platdata(dev);
298	struct syscon *syscon;
299	struct regmap_config syscon_config = syscon_regmap_config;
300	struct resource *res;
301	void __iomem *base;
302
303	syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
304	if (!syscon)
305		return -ENOMEM;
306
307	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
308	if (!res)
309		return -ENOENT;
310
311	base = devm_ioremap(dev, res->start, resource_size(res));
312	if (!base)
313		return -ENOMEM;
314
315	syscon_config.max_register = resource_size(res) - 4;
316	if (pdata)
317		syscon_config.name = pdata->label;
318	syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
319	if (IS_ERR(syscon->regmap)) {
320		dev_err(dev, "regmap init failed\n");
321		return PTR_ERR(syscon->regmap);
322	}
323
324	platform_set_drvdata(pdev, syscon);
325
326	dev_dbg(dev, "regmap %pR registered\n", res);
327
328	return 0;
329}
330
331static const struct platform_device_id syscon_ids[] = {
332	{ "syscon", },
333	{ }
334};
335
336static struct platform_driver syscon_driver = {
337	.driver = {
338		.name = "syscon",
339	},
340	.probe		= syscon_probe,
341	.id_table	= syscon_ids,
342};
343
344static int __init syscon_init(void)
345{
346	return platform_driver_register(&syscon_driver);
347}
348postcore_initcall(syscon_init);

 
  1/*
  2 * System Control Driver
  3 *
  4 * Copyright (C) 2012 Freescale Semiconductor, Inc.
  5 * Copyright (C) 2012 Linaro Ltd.
  6 *
  7 * Author: Dong Aisheng <dong.aisheng@linaro.org>
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License as published by
 11 * the Free Software Foundation; either version 2 of the License, or
 12 * (at your option) any later version.
 13 */
 14
 
 15#include <linux/err.h>
 
 16#include <linux/io.h>
 17#include <linux/module.h>
 18#include <linux/list.h>
 19#include <linux/of.h>
 20#include <linux/of_address.h>
 21#include <linux/of_platform.h>
 22#include <linux/platform_data/syscon.h>
 23#include <linux/platform_device.h>
 24#include <linux/regmap.h>
 
 25#include <linux/mfd/syscon.h>
 26#include <linux/slab.h>
 27
 28static struct platform_driver syscon_driver;
 29
 30static DEFINE_SPINLOCK(syscon_list_slock);
 31static LIST_HEAD(syscon_list);
 32
 33struct syscon {
 34	struct device_node *np;
 35	struct regmap *regmap;
 
 36	struct list_head list;
 37};
 38
 39static const struct regmap_config syscon_regmap_config = {
 40	.reg_bits = 32,
 41	.val_bits = 32,
 42	.reg_stride = 4,
 43};
 44
 45static struct syscon *of_syscon_register(struct device_node *np)
 46{
 
 47	struct syscon *syscon;
 48	struct regmap *regmap;
 49	void __iomem *base;
 50	u32 reg_io_width;
 51	int ret;
 52	struct regmap_config syscon_config = syscon_regmap_config;
 53	struct resource res;
 54
 55	if (!of_device_is_compatible(np, "syscon"))
 56		return ERR_PTR(-EINVAL);
 57
 58	syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
 59	if (!syscon)
 60		return ERR_PTR(-ENOMEM);
 61
 62	if (of_address_to_resource(np, 0, &res)) {
 63		ret = -ENOMEM;
 64		goto err_map;
 65	}
 66
 67	base = ioremap(res.start, resource_size(&res));
 68	if (!base) {
 69		ret = -ENOMEM;
 70		goto err_map;
 71	}
 72
 73	/* Parse the device's DT node for an endianness specification */
 74	if (of_property_read_bool(np, "big-endian"))
 75		syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
 76	else if (of_property_read_bool(np, "little-endian"))
 77		syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
 78	else if (of_property_read_bool(np, "native-endian"))
 79		syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
 80
 81	/*
 82	 * search for reg-io-width property in DT. If it is not provided,
 83	 * default to 4 bytes. regmap_init_mmio will return an error if values
 84	 * are invalid so there is no need to check them here.
 85	 */
 86	ret = of_property_read_u32(np, "reg-io-width", &reg_io_width);
 87	if (ret)
 88		reg_io_width = 4;
 89
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 90	syscon_config.reg_stride = reg_io_width;
 91	syscon_config.val_bits = reg_io_width * 8;
 92	syscon_config.max_register = resource_size(&res) - reg_io_width;
 93
 94	regmap = regmap_init_mmio(NULL, base, &syscon_config);
 
 95	if (IS_ERR(regmap)) {
 96		pr_err("regmap init failed\n");
 97		ret = PTR_ERR(regmap);
 98		goto err_regmap;
 99	}
100
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
101	syscon->regmap = regmap;
102	syscon->np = np;
103
104	spin_lock(&syscon_list_slock);
105	list_add_tail(&syscon->list, &syscon_list);
106	spin_unlock(&syscon_list_slock);
107
108	return syscon;
109
 
 
 
 
 
 
 
110err_regmap:
111	iounmap(base);
112err_map:
113	kfree(syscon);
114	return ERR_PTR(ret);
115}
116
117struct regmap *syscon_node_to_regmap(struct device_node *np)
 
118{
119	struct syscon *entry, *syscon = NULL;
120
121	spin_lock(&syscon_list_slock);
122
123	list_for_each_entry(entry, &syscon_list, list)
124		if (entry->np == np) {
125			syscon = entry;
126			break;
127		}
128
129	spin_unlock(&syscon_list_slock);
130
131	if (!syscon)
132		syscon = of_syscon_register(np);
133
134	if (IS_ERR(syscon))
135		return ERR_CAST(syscon);
136
137	return syscon->regmap;
138}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
139EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
140
141struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
142{
143	struct device_node *syscon_np;
144	struct regmap *regmap;
145
146	syscon_np = of_find_compatible_node(NULL, NULL, s);
147	if (!syscon_np)
148		return ERR_PTR(-ENODEV);
149
150	regmap = syscon_node_to_regmap(syscon_np);
151	of_node_put(syscon_np);
152
153	return regmap;
154}
155EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
156
157static int syscon_match_pdevname(struct device *dev, void *data)
 
158{
159	return !strcmp(dev_name(dev), (const char *)data);
160}
161
162struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
163{
164	struct device *dev;
165	struct syscon *syscon;
166
167	dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
168				 syscon_match_pdevname);
169	if (!dev)
170		return ERR_PTR(-EPROBE_DEFER);
171
172	syscon = dev_get_drvdata(dev);
 
173
174	return syscon->regmap;
175}
176EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
177
178struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
179					const char *property)
 
 
180{
181	struct device_node *syscon_np;
 
182	struct regmap *regmap;
 
 
183
184	if (property)
185		syscon_np = of_parse_phandle(np, property, 0);
186	else
187		syscon_np = np;
188
 
189	if (!syscon_np)
190		return ERR_PTR(-ENODEV);
191
192	regmap = syscon_node_to_regmap(syscon_np);
 
 
193	of_node_put(syscon_np);
194
195	return regmap;
196}
197EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
198
199static int syscon_probe(struct platform_device *pdev)
200{
201	struct device *dev = &pdev->dev;
202	struct syscon_platform_data *pdata = dev_get_platdata(dev);
203	struct syscon *syscon;
204	struct regmap_config syscon_config = syscon_regmap_config;
205	struct resource *res;
206	void __iomem *base;
207
208	syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
209	if (!syscon)
210		return -ENOMEM;
211
212	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
213	if (!res)
214		return -ENOENT;
215
216	base = devm_ioremap(dev, res->start, resource_size(res));
217	if (!base)
218		return -ENOMEM;
219
220	syscon_config.max_register = res->end - res->start - 3;
221	if (pdata)
222		syscon_config.name = pdata->label;
223	syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
224	if (IS_ERR(syscon->regmap)) {
225		dev_err(dev, "regmap init failed\n");
226		return PTR_ERR(syscon->regmap);
227	}
228
229	platform_set_drvdata(pdev, syscon);
230
231	dev_dbg(dev, "regmap %pR registered\n", res);
232
233	return 0;
234}
235
236static const struct platform_device_id syscon_ids[] = {
237	{ "syscon", },
238	{ }
239};
240
241static struct platform_driver syscon_driver = {
242	.driver = {
243		.name = "syscon",
244	},
245	.probe		= syscon_probe,
246	.id_table	= syscon_ids,
247};
248
249static int __init syscon_init(void)
250{
251	return platform_driver_register(&syscon_driver);
252}
253postcore_initcall(syscon_init);
254
255static void __exit syscon_exit(void)
256{
257	platform_driver_unregister(&syscon_driver);
258}
259module_exit(syscon_exit);
260
261MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
262MODULE_DESCRIPTION("System Control driver");
263MODULE_LICENSE("GPL v2");