xref: /openbmc/linux/drivers/pinctrl/berlin/berlin.c (revision b4e18b29)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Marvell Berlin SoC pinctrl core driver
4  *
5  * Copyright (C) 2014 Marvell Technology Group Ltd.
6  *
7  * Antoine Ténart <antoine.tenart@free-electrons.com>
8  */
9 
10 #include <linux/io.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/of_device.h>
16 #include <linux/pinctrl/pinctrl.h>
17 #include <linux/pinctrl/pinmux.h>
18 #include <linux/platform_device.h>
19 #include <linux/regmap.h>
20 #include <linux/slab.h>
21 
22 #include "../core.h"
23 #include "../pinctrl-utils.h"
24 #include "berlin.h"
25 
26 struct berlin_pinctrl {
27 	struct regmap *regmap;
28 	struct device *dev;
29 	const struct berlin_pinctrl_desc *desc;
30 	struct berlin_pinctrl_function *functions;
31 	unsigned nfunctions;
32 	struct pinctrl_dev *pctrl_dev;
33 };
34 
35 static int berlin_pinctrl_get_group_count(struct pinctrl_dev *pctrl_dev)
36 {
37 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
38 
39 	return pctrl->desc->ngroups;
40 }
41 
42 static const char *berlin_pinctrl_get_group_name(struct pinctrl_dev *pctrl_dev,
43 						 unsigned group)
44 {
45 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
46 
47 	return pctrl->desc->groups[group].name;
48 }
49 
50 static int berlin_pinctrl_dt_node_to_map(struct pinctrl_dev *pctrl_dev,
51 					 struct device_node *node,
52 					 struct pinctrl_map **map,
53 					 unsigned *num_maps)
54 {
55 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
56 	struct property *prop;
57 	const char *function_name, *group_name;
58 	unsigned reserved_maps = 0;
59 	int ret, ngroups;
60 
61 	*map = NULL;
62 	*num_maps = 0;
63 
64 	ret = of_property_read_string(node, "function", &function_name);
65 	if (ret) {
66 		dev_err(pctrl->dev,
67 			"missing function property in node %pOFn\n", node);
68 		return -EINVAL;
69 	}
70 
71 	ngroups = of_property_count_strings(node, "groups");
72 	if (ngroups < 0) {
73 		dev_err(pctrl->dev,
74 			"missing groups property in node %pOFn\n", node);
75 		return -EINVAL;
76 	}
77 
78 	ret = pinctrl_utils_reserve_map(pctrl_dev, map, &reserved_maps,
79 					num_maps, ngroups);
80 	if (ret) {
81 		dev_err(pctrl->dev, "can't reserve map: %d\n", ret);
82 		return ret;
83 	}
84 
85 	of_property_for_each_string(node, "groups", prop, group_name) {
86 		ret = pinctrl_utils_add_map_mux(pctrl_dev, map, &reserved_maps,
87 						num_maps, group_name,
88 						function_name);
89 		if (ret) {
90 			dev_err(pctrl->dev, "can't add map: %d\n", ret);
91 			return ret;
92 		}
93 	}
94 
95 	return 0;
96 }
97 
98 static const struct pinctrl_ops berlin_pinctrl_ops = {
99 	.get_groups_count	= &berlin_pinctrl_get_group_count,
100 	.get_group_name		= &berlin_pinctrl_get_group_name,
101 	.dt_node_to_map		= &berlin_pinctrl_dt_node_to_map,
102 	.dt_free_map		= &pinctrl_utils_free_map,
103 };
104 
105 static int berlin_pinmux_get_functions_count(struct pinctrl_dev *pctrl_dev)
106 {
107 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
108 
109 	return pctrl->nfunctions;
110 }
111 
112 static const char *berlin_pinmux_get_function_name(struct pinctrl_dev *pctrl_dev,
113 						   unsigned function)
114 {
115 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
116 
117 	return pctrl->functions[function].name;
118 }
119 
120 static int berlin_pinmux_get_function_groups(struct pinctrl_dev *pctrl_dev,
121 					     unsigned function,
122 					     const char * const **groups,
123 					     unsigned * const num_groups)
124 {
125 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
126 
127 	*groups = pctrl->functions[function].groups;
128 	*num_groups = pctrl->functions[function].ngroups;
129 
130 	return 0;
131 }
132 
133 static struct berlin_desc_function *
134 berlin_pinctrl_find_function_by_name(struct berlin_pinctrl *pctrl,
135 				     const struct berlin_desc_group *group,
136 				     const char *fname)
137 {
138 	struct berlin_desc_function *function = group->functions;
139 
140 	while (function->name) {
141 		if (!strcmp(function->name, fname))
142 			return function;
143 
144 		function++;
145 	}
146 
147 	return NULL;
148 }
149 
150 static int berlin_pinmux_set(struct pinctrl_dev *pctrl_dev,
151 			     unsigned function,
152 			     unsigned group)
153 {
154 	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
155 	const struct berlin_desc_group *group_desc = pctrl->desc->groups + group;
156 	struct berlin_pinctrl_function *func = pctrl->functions + function;
157 	struct berlin_desc_function *function_desc =
158 		berlin_pinctrl_find_function_by_name(pctrl, group_desc,
159 						     func->name);
160 	u32 mask, val;
161 
162 	if (!function_desc)
163 		return -EINVAL;
164 
165 	mask = GENMASK(group_desc->lsb + group_desc->bit_width - 1,
166 		       group_desc->lsb);
167 	val = function_desc->muxval << group_desc->lsb;
168 	regmap_update_bits(pctrl->regmap, group_desc->offset, mask, val);
169 
170 	return 0;
171 }
172 
173 static const struct pinmux_ops berlin_pinmux_ops = {
174 	.get_functions_count	= &berlin_pinmux_get_functions_count,
175 	.get_function_name	= &berlin_pinmux_get_function_name,
176 	.get_function_groups	= &berlin_pinmux_get_function_groups,
177 	.set_mux		= &berlin_pinmux_set,
178 };
179 
180 static int berlin_pinctrl_add_function(struct berlin_pinctrl *pctrl,
181 				       const char *name)
182 {
183 	struct berlin_pinctrl_function *function = pctrl->functions;
184 
185 	while (function->name) {
186 		if (!strcmp(function->name, name)) {
187 			function->ngroups++;
188 			return -EEXIST;
189 		}
190 		function++;
191 	}
192 
193 	function->name = name;
194 	function->ngroups = 1;
195 
196 	pctrl->nfunctions++;
197 
198 	return 0;
199 }
200 
201 static int berlin_pinctrl_build_state(struct platform_device *pdev)
202 {
203 	struct berlin_pinctrl *pctrl = platform_get_drvdata(pdev);
204 	const struct berlin_desc_group *desc_group;
205 	const struct berlin_desc_function *desc_function;
206 	int i, max_functions = 0;
207 
208 	pctrl->nfunctions = 0;
209 
210 	for (i = 0; i < pctrl->desc->ngroups; i++) {
211 		desc_group = pctrl->desc->groups + i;
212 		/* compute the maxiumum number of functions a group can have */
213 		max_functions += 1 << (desc_group->bit_width + 1);
214 	}
215 
216 	/* we will reallocate later */
217 	pctrl->functions = kcalloc(max_functions,
218 				   sizeof(*pctrl->functions), GFP_KERNEL);
219 	if (!pctrl->functions)
220 		return -ENOMEM;
221 
222 	/* register all functions */
223 	for (i = 0; i < pctrl->desc->ngroups; i++) {
224 		desc_group = pctrl->desc->groups + i;
225 		desc_function = desc_group->functions;
226 
227 		while (desc_function->name) {
228 			berlin_pinctrl_add_function(pctrl, desc_function->name);
229 			desc_function++;
230 		}
231 	}
232 
233 	pctrl->functions = krealloc(pctrl->functions,
234 				    pctrl->nfunctions * sizeof(*pctrl->functions),
235 				    GFP_KERNEL);
236 
237 	/* map functions to theirs groups */
238 	for (i = 0; i < pctrl->desc->ngroups; i++) {
239 		desc_group = pctrl->desc->groups + i;
240 		desc_function = desc_group->functions;
241 
242 		while (desc_function->name) {
243 			struct berlin_pinctrl_function
244 				*function = pctrl->functions;
245 			const char **groups;
246 			bool found = false;
247 
248 			while (function->name) {
249 				if (!strcmp(desc_function->name, function->name)) {
250 					found = true;
251 					break;
252 				}
253 				function++;
254 			}
255 
256 			if (!found) {
257 				kfree(pctrl->functions);
258 				return -EINVAL;
259 			}
260 
261 			if (!function->groups) {
262 				function->groups =
263 					devm_kcalloc(&pdev->dev,
264 						     function->ngroups,
265 						     sizeof(char *),
266 						     GFP_KERNEL);
267 
268 				if (!function->groups) {
269 					kfree(pctrl->functions);
270 					return -ENOMEM;
271 				}
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_regmap(struct platform_device *pdev,
295 				const struct berlin_pinctrl_desc *desc,
296 				struct regmap *regmap)
297 {
298 	struct device *dev = &pdev->dev;
299 	struct berlin_pinctrl *pctrl;
300 	int ret;
301 
302 	pctrl = devm_kzalloc(dev, sizeof(*pctrl), GFP_KERNEL);
303 	if (!pctrl)
304 		return -ENOMEM;
305 
306 	platform_set_drvdata(pdev, pctrl);
307 
308 	pctrl->regmap = regmap;
309 	pctrl->dev = &pdev->dev;
310 	pctrl->desc = desc;
311 
312 	ret = berlin_pinctrl_build_state(pdev);
313 	if (ret) {
314 		dev_err(dev, "cannot build driver state: %d\n", ret);
315 		return ret;
316 	}
317 
318 	pctrl->pctrl_dev = devm_pinctrl_register(dev, &berlin_pctrl_desc,
319 						 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