1/*
2 * Marvell Berlin SoC pinctrl core driver
3 *
4 * Copyright (C) 2014 Marvell Technology Group Ltd.
5 *
6 * Antoine T��nart <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
29struct 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
38static 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
45static 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
53static 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
103static 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
110static 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
117static 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
125static 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
138static struct berlin_desc_function *
139berlin_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
155static 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
178static 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
185static 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
206static 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
288static 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
295int 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
328int 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