xref: /openbmc/linux/drivers/pinctrl/berlin/berlin.c (revision 9cfc5c90)
1 /*
2  * Marvell Berlin SoC pinctrl core driver
3  *
4  * Copyright (C) 2014 Marvell Technology Group Ltd.
5  *
6  * Antoine Ténart <antoine.tenart@free-electrons.com>
7  *
8  * This file is licensed under the terms of the GNU General Public
9  * License version 2. This program is licensed "as is" without any
10  * warranty of any kind, whether express or implied.
11  */
12 
13 #include <linux/io.h>
14 #include <linux/mfd/syscon.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_address.h>
18 #include <linux/of_device.h>
19 #include <linux/pinctrl/pinctrl.h>
20 #include <linux/pinctrl/pinmux.h>
21 #include <linux/platform_device.h>
22 #include <linux/regmap.h>
23 #include <linux/slab.h>
24 
25 #include "../core.h"
26 #include "../pinctrl-utils.h"
27 #include "berlin.h"
28 
29 struct berlin_pinctrl {
30 	struct regmap *regmap;
31 	struct device *dev;
32 	const struct berlin_pinctrl_desc *desc;
33 	struct berlin_pinctrl_function *functions;
34 	unsigned nfunctions;
35 	struct pinctrl_dev *pctrl_dev;
36 };
37 
38 static int berlin_pinctrl_get_group_count(struct pinctrl_dev *pctrl_dev)
39 {
40 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
41 
42 	return pctrl->desc->ngroups;
43 }
44 
45 static const char *berlin_pinctrl_get_group_name(struct pinctrl_dev *pctrl_dev,
46 						 unsigned group)
47 {
48 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
49 
50 	return pctrl->desc->groups[group].name;
51 }
52 
53 static int berlin_pinctrl_dt_node_to_map(struct pinctrl_dev *pctrl_dev,
54 					 struct device_node *node,
55 					 struct pinctrl_map **map,
56 					 unsigned *num_maps)
57 {
58 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
59 	struct property *prop;
60 	const char *function_name, *group_name;
61 	unsigned reserved_maps = 0;
62 	int ret, ngroups;
63 
64 	*map = NULL;
65 	*num_maps = 0;
66 
67 	ret = of_property_read_string(node, "function", &function_name);
68 	if (ret) {
69 		dev_err(pctrl->dev,
70 			"missing function property in node %s\n",
71 			node->name);
72 		return -EINVAL;
73 	}
74 
75 	ngroups = of_property_count_strings(node, "groups");
76 	if (ngroups < 0) {
77 		dev_err(pctrl->dev,
78 			"missing groups property in node %s\n",
79 			node->name);
80 		return -EINVAL;
81 	}
82 
83 	ret = pinctrl_utils_reserve_map(pctrl_dev, map, &reserved_maps,
84 					num_maps, ngroups);
85 	if (ret) {
86 		dev_err(pctrl->dev, "can't reserve map: %d\n", ret);
87 		return ret;
88 	}
89 
90 	of_property_for_each_string(node, "groups", prop, group_name) {
91 		ret = pinctrl_utils_add_map_mux(pctrl_dev, map, &reserved_maps,
92 						num_maps, group_name,
93 						function_name);
94 		if (ret) {
95 			dev_err(pctrl->dev, "can't add map: %d\n", ret);
96 			return ret;
97 		}
98 	}
99 
100 	return 0;
101 }
102 
103 static const struct pinctrl_ops berlin_pinctrl_ops = {
104 	.get_groups_count	= &berlin_pinctrl_get_group_count,
105 	.get_group_name		= &berlin_pinctrl_get_group_name,
106 	.dt_node_to_map		= &berlin_pinctrl_dt_node_to_map,
107 	.dt_free_map		= &pinctrl_utils_dt_free_map,
108 };
109 
110 static int berlin_pinmux_get_functions_count(struct pinctrl_dev *pctrl_dev)
111 {
112 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
113 
114 	return pctrl->nfunctions;
115 }
116 
117 static const char *berlin_pinmux_get_function_name(struct pinctrl_dev *pctrl_dev,
118 						   unsigned function)
119 {
120 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
121 
122 	return pctrl->functions[function].name;
123 }
124 
125 static int berlin_pinmux_get_function_groups(struct pinctrl_dev *pctrl_dev,
126 					     unsigned function,
127 					     const char * const **groups,
128 					     unsigned * const num_groups)
129 {
130 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
131 
132 	*groups = pctrl->functions[function].groups;
133 	*num_groups = pctrl->functions[function].ngroups;
134 
135 	return 0;
136 }
137 
138 static struct berlin_desc_function *
139 berlin_pinctrl_find_function_by_name(struct berlin_pinctrl *pctrl,
140 				     const struct berlin_desc_group *group,
141 				     const char *fname)
142 {
143 	struct berlin_desc_function *function = group->functions;
144 
145 	while (function->name) {
146 		if (!strcmp(function->name, fname))
147 			return function;
148 
149 		function++;
150 	}
151 
152 	return NULL;
153 }
154 
155 static int berlin_pinmux_set(struct pinctrl_dev *pctrl_dev,
156 			     unsigned function,
157 			     unsigned group)
158 {
159 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
160 	const struct berlin_desc_group *group_desc = pctrl->desc->groups + group;
161 	struct berlin_pinctrl_function *func = pctrl->functions + function;
162 	struct berlin_desc_function *function_desc =
163 		berlin_pinctrl_find_function_by_name(pctrl, group_desc,
164 						     func->name);
165 	u32 mask, val;
166 
167 	if (!function_desc)
168 		return -EINVAL;
169 
170 	mask = GENMASK(group_desc->lsb + group_desc->bit_width - 1,
171 		       group_desc->lsb);
172 	val = function_desc->muxval << group_desc->lsb;
173 	regmap_update_bits(pctrl->regmap, group_desc->offset, mask, val);
174 
175 	return 0;
176 }
177 
178 static const struct pinmux_ops berlin_pinmux_ops = {
179 	.get_functions_count	= &berlin_pinmux_get_functions_count,
180 	.get_function_name	= &berlin_pinmux_get_function_name,
181 	.get_function_groups	= &berlin_pinmux_get_function_groups,
182 	.set_mux		= &berlin_pinmux_set,
183 };
184 
185 static int berlin_pinctrl_add_function(struct berlin_pinctrl *pctrl,
186 				       const char *name)
187 {
188 	struct berlin_pinctrl_function *function = pctrl->functions;
189 
190 	while (function->name) {
191 		if (!strcmp(function->name, name)) {
192 			function->ngroups++;
193 			return -EEXIST;
194 		}
195 		function++;
196 	}
197 
198 	function->name = name;
199 	function->ngroups = 1;
200 
201 	pctrl->nfunctions++;
202 
203 	return 0;
204 }
205 
206 static int berlin_pinctrl_build_state(struct platform_device *pdev)
207 {
208 	struct berlin_pinctrl *pctrl = platform_get_drvdata(pdev);
209 	struct berlin_desc_group const *desc_group;
210 	struct berlin_desc_function const *desc_function;
211 	int i, max_functions = 0;
212 
213 	pctrl->nfunctions = 0;
214 
215 	for (i = 0; i < pctrl->desc->ngroups; i++) {
216 		desc_group = pctrl->desc->groups + i;
217 		/* compute the maxiumum number of functions a group can have */
218 		max_functions += 1 << (desc_group->bit_width + 1);
219 	}
220 
221 	/* we will reallocate later */
222 	pctrl->functions = devm_kzalloc(&pdev->dev,
223 					max_functions * sizeof(*pctrl->functions),
224 					GFP_KERNEL);
225 	if (!pctrl->functions)
226 		return -ENOMEM;
227 
228 	/* register all functions */
229 	for (i = 0; i < pctrl->desc->ngroups; i++) {
230 		desc_group = pctrl->desc->groups + i;
231 		desc_function = desc_group->functions;
232 
233 		while (desc_function->name) {
234 			berlin_pinctrl_add_function(pctrl, desc_function->name);
235 			desc_function++;
236 		}
237 	}
238 
239 	pctrl->functions = krealloc(pctrl->functions,
240 				    pctrl->nfunctions * sizeof(*pctrl->functions),
241 				    GFP_KERNEL);
242 
243 	/* map functions to theirs groups */
244 	for (i = 0; i < pctrl->desc->ngroups; i++) {
245 		desc_group = pctrl->desc->groups + i;
246 		desc_function = desc_group->functions;
247 
248 		while (desc_function->name) {
249 			struct berlin_pinctrl_function
250 				*function = pctrl->functions;
251 			const char **groups;
252 			bool found = false;
253 
254 			while (function->name) {
255 				if (!strcmp(desc_function->name, function->name)) {
256 					found = true;
257 					break;
258 				}
259 				function++;
260 			}
261 
262 			if (!found)
263 				return -EINVAL;
264 
265 			if (!function->groups) {
266 				function->groups =
267 					devm_kzalloc(&pdev->dev,
268 						     function->ngroups * sizeof(char *),
269 						     GFP_KERNEL);
270 
271 				if (!function->groups)
272 					return -ENOMEM;
273 			}
274 
275 			groups = function->groups;
276 			while (*groups)
277 				groups++;
278 
279 			*groups = desc_group->name;
280 
281 			desc_function++;
282 		}
283 	}
284 
285 	return 0;
286 }
287 
288 static struct pinctrl_desc berlin_pctrl_desc = {
289 	.name		= "berlin-pinctrl",
290 	.pctlops	= &berlin_pinctrl_ops,
291 	.pmxops		= &berlin_pinmux_ops,
292 	.owner		= THIS_MODULE,
293 };
294 
295 int berlin_pinctrl_probe_regmap(struct platform_device *pdev,
296 				const struct berlin_pinctrl_desc *desc,
297 				struct regmap *regmap)
298 {
299 	struct device *dev = &pdev->dev;
300 	struct berlin_pinctrl *pctrl;
301 	int ret;
302 
303 	pctrl = devm_kzalloc(dev, sizeof(*pctrl), GFP_KERNEL);
304 	if (!pctrl)
305 		return -ENOMEM;
306 
307 	platform_set_drvdata(pdev, pctrl);
308 
309 	pctrl->regmap = regmap;
310 	pctrl->dev = &pdev->dev;
311 	pctrl->desc = desc;
312 
313 	ret = berlin_pinctrl_build_state(pdev);
314 	if (ret) {
315 		dev_err(dev, "cannot build driver state: %d\n", ret);
316 		return ret;
317 	}
318 
319 	pctrl->pctrl_dev = pinctrl_register(&berlin_pctrl_desc, dev, pctrl);
320 	if (IS_ERR(pctrl->pctrl_dev)) {
321 		dev_err(dev, "failed to register pinctrl driver\n");
322 		return PTR_ERR(pctrl->pctrl_dev);
323 	}
324 
325 	return 0;
326 }
327 
328 int berlin_pinctrl_probe(struct platform_device *pdev,
329 			 const struct berlin_pinctrl_desc *desc)
330 {
331 	struct device *dev = &pdev->dev;
332 	struct device_node *parent_np = of_get_parent(dev->of_node);
333 	struct regmap *regmap = syscon_node_to_regmap(parent_np);
334 
335 	of_node_put(parent_np);
336 	if (IS_ERR(regmap))
337 		return PTR_ERR(regmap);
338 
339 	return berlin_pinctrl_probe_regmap(pdev, desc, regmap);
340 }
341