xref: /openbmc/linux/drivers/pinctrl/berlin/berlin.c (revision 275876e2)
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/module.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/of_device.h>
18 #include <linux/pinctrl/pinctrl.h>
19 #include <linux/pinctrl/pinmux.h>
20 #include <linux/platform_device.h>
21 #include <linux/regmap.h>
22 #include <linux/slab.h>
23 
24 #include "../core.h"
25 #include "../pinctrl-utils.h"
26 #include "berlin.h"
27 
28 struct berlin_pinctrl {
29 	struct regmap *regmap;
30 	struct device *dev;
31 	const struct berlin_pinctrl_desc *desc;
32 	struct berlin_pinctrl_function *functions;
33 	unsigned nfunctions;
34 	struct pinctrl_dev *pctrl_dev;
35 };
36 
37 static int berlin_pinctrl_get_group_count(struct pinctrl_dev *pctrl_dev)
38 {
39 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
40 
41 	return pctrl->desc->ngroups;
42 }
43 
44 static const char *berlin_pinctrl_get_group_name(struct pinctrl_dev *pctrl_dev,
45 						 unsigned group)
46 {
47 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
48 
49 	return pctrl->desc->groups[group].name;
50 }
51 
52 static int berlin_pinctrl_dt_node_to_map(struct pinctrl_dev *pctrl_dev,
53 					 struct device_node *node,
54 					 struct pinctrl_map **map,
55 					 unsigned *num_maps)
56 {
57 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
58 	struct property *prop;
59 	const char *function_name, *group_name;
60 	unsigned reserved_maps = 0;
61 	int ret, ngroups;
62 
63 	*map = NULL;
64 	*num_maps = 0;
65 
66 	ret = of_property_read_string(node, "function", &function_name);
67 	if (ret) {
68 		dev_err(pctrl->dev,
69 			"missing function property in node %s\n",
70 			node->name);
71 		return -EINVAL;
72 	}
73 
74 	ngroups = of_property_count_strings(node, "groups");
75 	if (ngroups < 0) {
76 		dev_err(pctrl->dev,
77 			"missing groups property in node %s\n",
78 			node->name);
79 		return -EINVAL;
80 	}
81 
82 	ret = pinctrl_utils_reserve_map(pctrl_dev, map, &reserved_maps,
83 					num_maps, ngroups);
84 	if (ret) {
85 		dev_err(pctrl->dev, "can't reserve map: %d\n", ret);
86 		return ret;
87 	}
88 
89 	of_property_for_each_string(node, "groups", prop, group_name) {
90 		ret = pinctrl_utils_add_map_mux(pctrl_dev, map, &reserved_maps,
91 						num_maps, group_name,
92 						function_name);
93 		if (ret) {
94 			dev_err(pctrl->dev, "can't add map: %d\n", ret);
95 			return ret;
96 		}
97 	}
98 
99 	return 0;
100 }
101 
102 static void berlin_pinctrl_dt_free_map(struct pinctrl_dev *pctrl_dev,
103 				       struct pinctrl_map *map,
104 				       unsigned nmaps)
105 {
106 	int i;
107 
108 	for (i = 0; i < nmaps; i++) {
109 		if (map[i].type == PIN_MAP_TYPE_MUX_GROUP) {
110 			kfree(map[i].data.mux.group);
111 
112 			/* a function can be applied to multiple groups */
113 			if (i == 0)
114 				kfree(map[i].data.mux.function);
115 		}
116 	}
117 
118 	kfree(map);
119 }
120 
121 static const struct pinctrl_ops berlin_pinctrl_ops = {
122 	.get_groups_count	= &berlin_pinctrl_get_group_count,
123 	.get_group_name		= &berlin_pinctrl_get_group_name,
124 	.dt_node_to_map		= &berlin_pinctrl_dt_node_to_map,
125 	.dt_free_map		= &berlin_pinctrl_dt_free_map,
126 };
127 
128 static int berlin_pinmux_get_functions_count(struct pinctrl_dev *pctrl_dev)
129 {
130 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
131 
132 	return pctrl->nfunctions;
133 }
134 
135 static const char *berlin_pinmux_get_function_name(struct pinctrl_dev *pctrl_dev,
136 						   unsigned function)
137 {
138 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
139 
140 	return pctrl->functions[function].name;
141 }
142 
143 static int berlin_pinmux_get_function_groups(struct pinctrl_dev *pctrl_dev,
144 					     unsigned function,
145 					     const char * const **groups,
146 					     unsigned * const num_groups)
147 {
148 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
149 
150 	*groups = pctrl->functions[function].groups;
151 	*num_groups = pctrl->functions[function].ngroups;
152 
153 	return 0;
154 }
155 
156 static struct berlin_desc_function *
157 berlin_pinctrl_find_function_by_name(struct berlin_pinctrl *pctrl,
158 				     const struct berlin_desc_group *group,
159 				     const char *fname)
160 {
161 	struct berlin_desc_function *function = group->functions;
162 
163 	while (function->name) {
164 		if (!strcmp(function->name, fname))
165 			return function;
166 
167 		function++;
168 	}
169 
170 	return NULL;
171 }
172 
173 static int berlin_pinmux_enable(struct pinctrl_dev *pctrl_dev,
174 				unsigned function,
175 				unsigned group)
176 {
177 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
178 	const struct berlin_desc_group *group_desc = pctrl->desc->groups + group;
179 	struct berlin_pinctrl_function *func = pctrl->functions + function;
180 	struct berlin_desc_function *function_desc =
181 		berlin_pinctrl_find_function_by_name(pctrl, group_desc,
182 						     func->name);
183 	u32 mask, val;
184 
185 	if (!function_desc)
186 		return -EINVAL;
187 
188 	mask = GENMASK(group_desc->lsb + group_desc->bit_width - 1,
189 		       group_desc->lsb);
190 	val = function_desc->muxval << group_desc->lsb;
191 	regmap_update_bits(pctrl->regmap, group_desc->offset, mask, val);
192 
193 	return 0;
194 }
195 
196 static const struct pinmux_ops berlin_pinmux_ops = {
197 	.get_functions_count	= &berlin_pinmux_get_functions_count,
198 	.get_function_name	= &berlin_pinmux_get_function_name,
199 	.get_function_groups	= &berlin_pinmux_get_function_groups,
200 	.enable			= &berlin_pinmux_enable,
201 };
202 
203 static int berlin_pinctrl_add_function(struct berlin_pinctrl *pctrl,
204 				       const char *name)
205 {
206 	struct berlin_pinctrl_function *function = pctrl->functions;
207 
208 	while (function->name) {
209 		if (!strcmp(function->name, name)) {
210 			function->ngroups++;
211 			return -EEXIST;
212 		}
213 		function++;
214 	}
215 
216 	function->name = name;
217 	function->ngroups = 1;
218 
219 	pctrl->nfunctions++;
220 
221 	return 0;
222 }
223 
224 static int berlin_pinctrl_build_state(struct platform_device *pdev)
225 {
226 	struct berlin_pinctrl *pctrl = platform_get_drvdata(pdev);
227 	struct berlin_desc_group const *desc_group;
228 	struct berlin_desc_function const *desc_function;
229 	int i, max_functions = 0;
230 
231 	pctrl->nfunctions = 0;
232 
233 	for (i = 0; i < pctrl->desc->ngroups; i++) {
234 		desc_group = pctrl->desc->groups + i;
235 		/* compute the maxiumum number of functions a group can have */
236 		max_functions += 1 << (desc_group->bit_width + 1);
237 	}
238 
239 	/* we will reallocate later */
240 	pctrl->functions = devm_kzalloc(&pdev->dev,
241 					max_functions * sizeof(*pctrl->functions),
242 					GFP_KERNEL);
243 	if (!pctrl->functions)
244 		return -ENOMEM;
245 
246 	/* register all functions */
247 	for (i = 0; i < pctrl->desc->ngroups; i++) {
248 		desc_group = pctrl->desc->groups + i;
249 		desc_function = desc_group->functions;
250 
251 		while (desc_function->name) {
252 			berlin_pinctrl_add_function(pctrl, desc_function->name);
253 			desc_function++;
254 		}
255 	}
256 
257 	pctrl->functions = krealloc(pctrl->functions,
258 				    pctrl->nfunctions * sizeof(*pctrl->functions),
259 				    GFP_KERNEL);
260 
261 	/* map functions to theirs groups */
262 	for (i = 0; i < pctrl->desc->ngroups; i++) {
263 		desc_group = pctrl->desc->groups + i;
264 		desc_function = desc_group->functions;
265 
266 		while (desc_function->name) {
267 			struct berlin_pinctrl_function
268 				*function = pctrl->functions;
269 			const char **groups;
270 			bool found = false;
271 
272 			while (function->name) {
273 				if (!strcmp(desc_function->name, function->name)) {
274 					found = true;
275 					break;
276 				}
277 				function++;
278 			}
279 
280 			if (!found)
281 				return -EINVAL;
282 
283 			if (!function->groups) {
284 				function->groups =
285 					devm_kzalloc(&pdev->dev,
286 						     function->ngroups * sizeof(char *),
287 						     GFP_KERNEL);
288 
289 				if (!function->groups)
290 					return -ENOMEM;
291 			}
292 
293 			groups = function->groups;
294 			while (*groups)
295 				groups++;
296 
297 			*groups = desc_group->name;
298 
299 			desc_function++;
300 		}
301 	}
302 
303 	return 0;
304 }
305 
306 static struct pinctrl_desc berlin_pctrl_desc = {
307 	.name		= "berlin-pinctrl",
308 	.pctlops	= &berlin_pinctrl_ops,
309 	.pmxops		= &berlin_pinmux_ops,
310 	.owner		= THIS_MODULE,
311 };
312 
313 int berlin_pinctrl_probe(struct platform_device *pdev,
314 			 const struct berlin_pinctrl_desc *desc)
315 {
316 	struct device *dev = &pdev->dev;
317 	struct berlin_pinctrl *pctrl;
318 	struct regmap *regmap;
319 	int ret;
320 
321 	regmap = dev_get_regmap(&pdev->dev, NULL);
322 	if (!regmap)
323 		return -ENODEV;
324 
325 	pctrl = devm_kzalloc(dev, sizeof(*pctrl), GFP_KERNEL);
326 	if (!pctrl)
327 		return -ENOMEM;
328 
329 	platform_set_drvdata(pdev, pctrl);
330 
331 	pctrl->regmap = regmap;
332 	pctrl->dev = &pdev->dev;
333 	pctrl->desc = desc;
334 
335 	ret = berlin_pinctrl_build_state(pdev);
336 	if (ret) {
337 		dev_err(dev, "cannot build driver state: %d\n", ret);
338 		return ret;
339 	}
340 
341 	pctrl->pctrl_dev = pinctrl_register(&berlin_pctrl_desc, dev, pctrl);
342 	if (!pctrl->pctrl_dev) {
343 		dev_err(dev, "failed to register pinctrl driver\n");
344 		return -EINVAL;
345 	}
346 
347 	return 0;
348 }
349