berlin.c

  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
 26struct berlin_pinctrl {
 27	struct regmap *regmap;
 28	struct device *dev;
 29	const struct berlin_pinctrl_desc *desc;
 30	struct pinfunction *functions;
 31	unsigned nfunctions;
 32	struct pinctrl_dev *pctrl_dev;
 33};
 34
 35static 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
 42static 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
 50static 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
 98static 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
105static 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
112static 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
120static int berlin_pinmux_get_function_groups(struct pinctrl_dev *pctrl_dev,
121					     unsigned function,
122					     const char * const **groups,
123					     unsigned * const ngroups)
124{
125	struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
126
127	*groups = pctrl->functions[function].groups;
128	*ngroups = pctrl->functions[function].ngroups;
129
130	return 0;
131}
132
133static struct berlin_desc_function *
134berlin_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
150static 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 pinfunction *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
173static 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
180static int berlin_pinctrl_add_function(struct berlin_pinctrl *pctrl,
181				       const char *name)
182{
183	struct pinfunction *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
201static 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	struct pinfunction *new_functions;
208
209	pctrl->nfunctions = 0;
210
211	for (i = 0; i < pctrl->desc->ngroups; i++) {
212		desc_group = pctrl->desc->groups + i;
213		/* compute the maximum number of functions a group can have */
214		max_functions += 1 << (desc_group->bit_width + 1);
215	}
216
217	/* we will reallocate later */
218	pctrl->functions = kcalloc(max_functions, 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	new_functions = krealloc(pctrl->functions,
234				    pctrl->nfunctions * sizeof(*pctrl->functions),
235				    GFP_KERNEL);
236	if (!new_functions) {
237		kfree(pctrl->functions);
238		return -ENOMEM;
239	}
240
241	pctrl->functions = new_functions;
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 pinfunction *function = pctrl->functions;
249			const char **groups;
250			bool found = false;
251
252			while (function->name) {
253				if (!strcmp(desc_function->name, function->name)) {
254					found = true;
255					break;
256				}
257				function++;
258			}
259
260			if (!found) {
261				kfree(pctrl->functions);
262				return -EINVAL;
263			}
264
265			if (!function->groups) {
266				function->groups =
267					devm_kcalloc(&pdev->dev,
268						     function->ngroups,
269						     sizeof(*function->groups),
270						     GFP_KERNEL);
271				if (!function->groups) {
272					kfree(pctrl->functions);
273					return -ENOMEM;
274				}
275			}
276
277			groups = (const char **)function->groups;
278			while (*groups)
279				groups++;
280
281			*groups = desc_group->name;
282
283			desc_function++;
284		}
285	}
286
287	return 0;
288}
289
290static const struct pinctrl_desc berlin_pctrl_desc = {
291	.name		= "berlin-pinctrl",
292	.pctlops	= &berlin_pinctrl_ops,
293	.pmxops		= &berlin_pinmux_ops,
294	.owner		= THIS_MODULE,
295};
296
297int berlin_pinctrl_probe_regmap(struct platform_device *pdev,
298				const struct berlin_pinctrl_desc *desc,
299				struct regmap *regmap)
300{
301	struct device *dev = &pdev->dev;
302	struct berlin_pinctrl *pctrl;
303	int ret;
304
305	pctrl = devm_kzalloc(dev, sizeof(*pctrl), GFP_KERNEL);
306	if (!pctrl)
307		return -ENOMEM;
308
309	platform_set_drvdata(pdev, pctrl);
310
311	pctrl->regmap = regmap;
312	pctrl->dev = &pdev->dev;
313	pctrl->desc = desc;
314
315	ret = berlin_pinctrl_build_state(pdev);
316	if (ret) {
317		dev_err(dev, "cannot build driver state: %d\n", ret);
318		return ret;
319	}
320
321	pctrl->pctrl_dev = devm_pinctrl_register(dev, &berlin_pctrl_desc,
322						 pctrl);
323	if (IS_ERR(pctrl->pctrl_dev)) {
324		dev_err(dev, "failed to register pinctrl driver\n");
325		return PTR_ERR(pctrl->pctrl_dev);
326	}
327
328	return 0;
329}
330
331int berlin_pinctrl_probe(struct platform_device *pdev,
332			 const struct berlin_pinctrl_desc *desc)
333{
334	struct device *dev = &pdev->dev;
335	struct device_node *parent_np = of_get_parent(dev->of_node);
336	struct regmap *regmap = syscon_node_to_regmap(parent_np);
337
338	of_node_put(parent_np);
339	if (IS_ERR(regmap))
340		return PTR_ERR(regmap);
341
342	return berlin_pinctrl_probe_regmap(pdev, desc, regmap);
343}