xref: /linux/drivers/pinctrl/berlin/berlin.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
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 const struct pinctrl_ops berlin_pinctrl_ops = {
103 	.get_groups_count	= &berlin_pinctrl_get_group_count,
104 	.get_group_name		= &berlin_pinctrl_get_group_name,
105 	.dt_node_to_map		= &berlin_pinctrl_dt_node_to_map,
106 	.dt_free_map		= &pinctrl_utils_dt_free_map,
107 };
108 
109 static int berlin_pinmux_get_functions_count(struct pinctrl_dev *pctrl_dev)
110 {
111 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
112 
113 	return pctrl->nfunctions;
114 }
115 
116 static const char *berlin_pinmux_get_function_name(struct pinctrl_dev *pctrl_dev,
117 						   unsigned function)
118 {
119 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
120 
121 	return pctrl->functions[function].name;
122 }
123 
124 static int berlin_pinmux_get_function_groups(struct pinctrl_dev *pctrl_dev,
125 					     unsigned function,
126 					     const char * const **groups,
127 					     unsigned * const num_groups)
128 {
129 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
130 
131 	*groups = pctrl->functions[function].groups;
132 	*num_groups = pctrl->functions[function].ngroups;
133 
134 	return 0;
135 }
136 
137 static struct berlin_desc_function *
138 berlin_pinctrl_find_function_by_name(struct berlin_pinctrl *pctrl,
139 				     const struct berlin_desc_group *group,
140 				     const char *fname)
141 {
142 	struct berlin_desc_function *function = group->functions;
143 
144 	while (function->name) {
145 		if (!strcmp(function->name, fname))
146 			return function;
147 
148 		function++;
149 	}
150 
151 	return NULL;
152 }
153 
154 static int berlin_pinmux_set(struct pinctrl_dev *pctrl_dev,
155 			     unsigned function,
156 			     unsigned group)
157 {
158 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
159 	const struct berlin_desc_group *group_desc = pctrl->desc->groups + group;
160 	struct berlin_pinctrl_function *func = pctrl->functions + function;
161 	struct berlin_desc_function *function_desc =
162 		berlin_pinctrl_find_function_by_name(pctrl, group_desc,
163 						     func->name);
164 	u32 mask, val;
165 
166 	if (!function_desc)
167 		return -EINVAL;
168 
169 	mask = GENMASK(group_desc->lsb + group_desc->bit_width - 1,
170 		       group_desc->lsb);
171 	val = function_desc->muxval << group_desc->lsb;
172 	regmap_update_bits(pctrl->regmap, group_desc->offset, mask, val);
173 
174 	return 0;
175 }
176 
177 static const struct pinmux_ops berlin_pinmux_ops = {
178 	.get_functions_count	= &berlin_pinmux_get_functions_count,
179 	.get_function_name	= &berlin_pinmux_get_function_name,
180 	.get_function_groups	= &berlin_pinmux_get_function_groups,
181 	.set_mux		= &berlin_pinmux_set,
182 };
183 
184 static int berlin_pinctrl_add_function(struct berlin_pinctrl *pctrl,
185 				       const char *name)
186 {
187 	struct berlin_pinctrl_function *function = pctrl->functions;
188 
189 	while (function->name) {
190 		if (!strcmp(function->name, name)) {
191 			function->ngroups++;
192 			return -EEXIST;
193 		}
194 		function++;
195 	}
196 
197 	function->name = name;
198 	function->ngroups = 1;
199 
200 	pctrl->nfunctions++;
201 
202 	return 0;
203 }
204 
205 static int berlin_pinctrl_build_state(struct platform_device *pdev)
206 {
207 	struct berlin_pinctrl *pctrl = platform_get_drvdata(pdev);
208 	struct berlin_desc_group const *desc_group;
209 	struct berlin_desc_function const *desc_function;
210 	int i, max_functions = 0;
211 
212 	pctrl->nfunctions = 0;
213 
214 	for (i = 0; i < pctrl->desc->ngroups; i++) {
215 		desc_group = pctrl->desc->groups + i;
216 		/* compute the maxiumum number of functions a group can have */
217 		max_functions += 1 << (desc_group->bit_width + 1);
218 	}
219 
220 	/* we will reallocate later */
221 	pctrl->functions = devm_kzalloc(&pdev->dev,
222 					max_functions * sizeof(*pctrl->functions),
223 					GFP_KERNEL);
224 	if (!pctrl->functions)
225 		return -ENOMEM;
226 
227 	/* register all functions */
228 	for (i = 0; i < pctrl->desc->ngroups; i++) {
229 		desc_group = pctrl->desc->groups + i;
230 		desc_function = desc_group->functions;
231 
232 		while (desc_function->name) {
233 			berlin_pinctrl_add_function(pctrl, desc_function->name);
234 			desc_function++;
235 		}
236 	}
237 
238 	pctrl->functions = krealloc(pctrl->functions,
239 				    pctrl->nfunctions * sizeof(*pctrl->functions),
240 				    GFP_KERNEL);
241 
242 	/* map functions to theirs groups */
243 	for (i = 0; i < pctrl->desc->ngroups; i++) {
244 		desc_group = pctrl->desc->groups + i;
245 		desc_function = desc_group->functions;
246 
247 		while (desc_function->name) {
248 			struct berlin_pinctrl_function
249 				*function = pctrl->functions;
250 			const char **groups;
251 			bool found = false;
252 
253 			while (function->name) {
254 				if (!strcmp(desc_function->name, function->name)) {
255 					found = true;
256 					break;
257 				}
258 				function++;
259 			}
260 
261 			if (!found)
262 				return -EINVAL;
263 
264 			if (!function->groups) {
265 				function->groups =
266 					devm_kzalloc(&pdev->dev,
267 						     function->ngroups * sizeof(char *),
268 						     GFP_KERNEL);
269 
270 				if (!function->groups)
271 					return -ENOMEM;
272 			}
273 
274 			groups = function->groups;
275 			while (*groups)
276 				groups++;
277 
278 			*groups = desc_group->name;
279 
280 			desc_function++;
281 		}
282 	}
283 
284 	return 0;
285 }
286 
287 static struct pinctrl_desc berlin_pctrl_desc = {
288 	.name		= "berlin-pinctrl",
289 	.pctlops	= &berlin_pinctrl_ops,
290 	.pmxops		= &berlin_pinmux_ops,
291 	.owner		= THIS_MODULE,
292 };
293 
294 int berlin_pinctrl_probe(struct platform_device *pdev,
295 			 const struct berlin_pinctrl_desc *desc)
296 {
297 	struct device *dev = &pdev->dev;
298 	struct berlin_pinctrl *pctrl;
299 	struct regmap *regmap;
300 	int ret;
301 
302 	regmap = dev_get_regmap(&pdev->dev, NULL);
303 	if (!regmap)
304 		return -ENODEV;
305 
306 	pctrl = devm_kzalloc(dev, sizeof(*pctrl), GFP_KERNEL);
307 	if (!pctrl)
308 		return -ENOMEM;
309 
310 	platform_set_drvdata(pdev, pctrl);
311 
312 	pctrl->regmap = regmap;
313 	pctrl->dev = &pdev->dev;
314 	pctrl->desc = desc;
315 
316 	ret = berlin_pinctrl_build_state(pdev);
317 	if (ret) {
318 		dev_err(dev, "cannot build driver state: %d\n", ret);
319 		return ret;
320 	}
321 
322 	pctrl->pctrl_dev = pinctrl_register(&berlin_pctrl_desc, dev, pctrl);
323 	if (!pctrl->pctrl_dev) {
324 		dev_err(dev, "failed to register pinctrl driver\n");
325 		return -EINVAL;
326 	}
327 
328 	return 0;
329 }
330