[go: nahoru, domu]

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
28struct 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
37static 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
44static 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
52static 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
102static 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
109static 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
116static 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
124static 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
137static struct berlin_desc_function *
138berlin_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
154static 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
177static 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
184static 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
205static 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
287static 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
294int 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