1 /*
2  * Driver for the ST Microelectronics SPEAr pinmux
3  *
4  * Copyright (C) 2012 ST Microelectronics
5  * Viresh Kumar <vireshk@kernel.org>
6  *
7  * Inspired from:
8  * - U300 Pinctl drivers
9  * - Tegra Pinctl drivers
10  *
11  * This file is licensed under the terms of the GNU General Public
12  * License version 2. This program is licensed "as is" without any
13  * warranty of any kind, whether express or implied.
14  */
15 
16 #include <linux/err.h>
17 #include <linux/mfd/syscon.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_address.h>
21 #include <linux/of_gpio.h>
22 #include <linux/platform_device.h>
23 #include <linux/seq_file.h>
24 #include <linux/slab.h>
25 
26 #include <linux/pinctrl/machine.h>
27 #include <linux/pinctrl/pinctrl.h>
28 #include <linux/pinctrl/pinmux.h>
29 
30 #include "pinctrl-spear.h"
31 
32 #define DRIVER_NAME "spear-pinmux"
33 
34 static void muxregs_endisable(struct spear_pmx *pmx,
35 		struct spear_muxreg *muxregs, u8 count, bool enable)
36 {
37 	struct spear_muxreg *muxreg;
38 	u32 val, temp, j;
39 
40 	for (j = 0; j < count; j++) {
41 		muxreg = &muxregs[j];
42 
43 		val = pmx_readl(pmx, muxreg->reg);
44 		val &= ~muxreg->mask;
45 
46 		if (enable)
47 			temp = muxreg->val;
48 		else
49 			temp = ~muxreg->val;
50 
51 		val |= muxreg->mask & temp;
52 		pmx_writel(pmx, val, muxreg->reg);
53 	}
54 }
55 
56 static int set_mode(struct spear_pmx *pmx, int mode)
57 {
58 	struct spear_pmx_mode *pmx_mode = NULL;
59 	int i;
60 	u32 val;
61 
62 	if (!pmx->machdata->pmx_modes || !pmx->machdata->npmx_modes)
63 		return -EINVAL;
64 
65 	for (i = 0; i < pmx->machdata->npmx_modes; i++) {
66 		if (pmx->machdata->pmx_modes[i]->mode == (1 << mode)) {
67 			pmx_mode = pmx->machdata->pmx_modes[i];
68 			break;
69 		}
70 	}
71 
72 	if (!pmx_mode)
73 		return -EINVAL;
74 
75 	val = pmx_readl(pmx, pmx_mode->reg);
76 	val &= ~pmx_mode->mask;
77 	val |= pmx_mode->val;
78 	pmx_writel(pmx, val, pmx_mode->reg);
79 
80 	pmx->machdata->mode = pmx_mode->mode;
81 	dev_info(pmx->dev, "Configured Mode: %s with id: %x\n\n",
82 			pmx_mode->name ? pmx_mode->name : "no_name",
83 			pmx_mode->reg);
84 
85 	return 0;
86 }
87 
88 void pmx_init_gpio_pingroup_addr(struct spear_gpio_pingroup *gpio_pingroup,
89 				 unsigned count, u16 reg)
90 {
91 	int i, j;
92 
93 	for (i = 0; i < count; i++)
94 		for (j = 0; j < gpio_pingroup[i].nmuxregs; j++)
95 			gpio_pingroup[i].muxregs[j].reg = reg;
96 }
97 
98 void pmx_init_addr(struct spear_pinctrl_machdata *machdata, u16 reg)
99 {
100 	struct spear_pingroup *pgroup;
101 	struct spear_modemux *modemux;
102 	int i, j, group;
103 
104 	for (group = 0; group < machdata->ngroups; group++) {
105 		pgroup = machdata->groups[group];
106 
107 		for (i = 0; i < pgroup->nmodemuxs; i++) {
108 			modemux = &pgroup->modemuxs[i];
109 
110 			for (j = 0; j < modemux->nmuxregs; j++)
111 				if (modemux->muxregs[j].reg == 0xFFFF)
112 					modemux->muxregs[j].reg = reg;
113 		}
114 	}
115 }
116 
117 static int spear_pinctrl_get_groups_cnt(struct pinctrl_dev *pctldev)
118 {
119 	struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
120 
121 	return pmx->machdata->ngroups;
122 }
123 
124 static const char *spear_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
125 		unsigned group)
126 {
127 	struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
128 
129 	return pmx->machdata->groups[group]->name;
130 }
131 
132 static int spear_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
133 		unsigned group, const unsigned **pins, unsigned *num_pins)
134 {
135 	struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
136 
137 	*pins = pmx->machdata->groups[group]->pins;
138 	*num_pins = pmx->machdata->groups[group]->npins;
139 
140 	return 0;
141 }
142 
143 static void spear_pinctrl_pin_dbg_show(struct pinctrl_dev *pctldev,
144 		struct seq_file *s, unsigned offset)
145 {
146 	seq_printf(s, " " DRIVER_NAME);
147 }
148 
149 static int spear_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
150 					struct device_node *np_config,
151 					struct pinctrl_map **map,
152 					unsigned *num_maps)
153 {
154 	struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
155 	struct device_node *np;
156 	struct property *prop;
157 	const char *function, *group;
158 	int ret, index = 0, count = 0;
159 
160 	/* calculate number of maps required */
161 	for_each_child_of_node(np_config, np) {
162 		ret = of_property_read_string(np, "st,function", &function);
163 		if (ret < 0) {
164 			of_node_put(np);
165 			return ret;
166 		}
167 
168 		ret = of_property_count_strings(np, "st,pins");
169 		if (ret < 0) {
170 			of_node_put(np);
171 			return ret;
172 		}
173 
174 		count += ret;
175 	}
176 
177 	if (!count) {
178 		dev_err(pmx->dev, "No child nodes passed via DT\n");
179 		return -ENODEV;
180 	}
181 
182 	*map = kcalloc(count, sizeof(**map), GFP_KERNEL);
183 	if (!*map)
184 		return -ENOMEM;
185 
186 	for_each_child_of_node(np_config, np) {
187 		of_property_read_string(np, "st,function", &function);
188 		of_property_for_each_string(np, "st,pins", prop, group) {
189 			(*map)[index].type = PIN_MAP_TYPE_MUX_GROUP;
190 			(*map)[index].data.mux.group = group;
191 			(*map)[index].data.mux.function = function;
192 			index++;
193 		}
194 	}
195 
196 	*num_maps = count;
197 
198 	return 0;
199 }
200 
201 static void spear_pinctrl_dt_free_map(struct pinctrl_dev *pctldev,
202 				      struct pinctrl_map *map,
203 				      unsigned num_maps)
204 {
205 	kfree(map);
206 }
207 
208 static const struct pinctrl_ops spear_pinctrl_ops = {
209 	.get_groups_count = spear_pinctrl_get_groups_cnt,
210 	.get_group_name = spear_pinctrl_get_group_name,
211 	.get_group_pins = spear_pinctrl_get_group_pins,
212 	.pin_dbg_show = spear_pinctrl_pin_dbg_show,
213 	.dt_node_to_map = spear_pinctrl_dt_node_to_map,
214 	.dt_free_map = spear_pinctrl_dt_free_map,
215 };
216 
217 static int spear_pinctrl_get_funcs_count(struct pinctrl_dev *pctldev)
218 {
219 	struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
220 
221 	return pmx->machdata->nfunctions;
222 }
223 
224 static const char *spear_pinctrl_get_func_name(struct pinctrl_dev *pctldev,
225 		unsigned function)
226 {
227 	struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
228 
229 	return pmx->machdata->functions[function]->name;
230 }
231 
232 static int spear_pinctrl_get_func_groups(struct pinctrl_dev *pctldev,
233 		unsigned function, const char *const **groups,
234 		unsigned * const ngroups)
235 {
236 	struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
237 
238 	*groups = pmx->machdata->functions[function]->groups;
239 	*ngroups = pmx->machdata->functions[function]->ngroups;
240 
241 	return 0;
242 }
243 
244 static int spear_pinctrl_endisable(struct pinctrl_dev *pctldev,
245 		unsigned function, unsigned group, bool enable)
246 {
247 	struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
248 	const struct spear_pingroup *pgroup;
249 	const struct spear_modemux *modemux;
250 	int i;
251 	bool found = false;
252 
253 	pgroup = pmx->machdata->groups[group];
254 
255 	for (i = 0; i < pgroup->nmodemuxs; i++) {
256 		modemux = &pgroup->modemuxs[i];
257 
258 		/* SoC have any modes */
259 		if (pmx->machdata->modes_supported) {
260 			if (!(pmx->machdata->mode & modemux->modes))
261 				continue;
262 		}
263 
264 		found = true;
265 		muxregs_endisable(pmx, modemux->muxregs, modemux->nmuxregs,
266 				enable);
267 	}
268 
269 	if (!found) {
270 		dev_err(pmx->dev, "pinmux group: %s not supported\n",
271 				pgroup->name);
272 		return -ENODEV;
273 	}
274 
275 	return 0;
276 }
277 
278 static int spear_pinctrl_set_mux(struct pinctrl_dev *pctldev, unsigned function,
279 		unsigned group)
280 {
281 	return spear_pinctrl_endisable(pctldev, function, group, true);
282 }
283 
284 /* gpio with pinmux */
285 static struct spear_gpio_pingroup *get_gpio_pingroup(struct spear_pmx *pmx,
286 		unsigned pin)
287 {
288 	struct spear_gpio_pingroup *gpio_pingroup;
289 	int i, j;
290 
291 	if (!pmx->machdata->gpio_pingroups)
292 		return NULL;
293 
294 	for (i = 0; i < pmx->machdata->ngpio_pingroups; i++) {
295 		gpio_pingroup = &pmx->machdata->gpio_pingroups[i];
296 
297 		for (j = 0; j < gpio_pingroup->npins; j++) {
298 			if (gpio_pingroup->pins[j] == pin)
299 				return gpio_pingroup;
300 		}
301 	}
302 
303 	return NULL;
304 }
305 
306 static int gpio_request_endisable(struct pinctrl_dev *pctldev,
307 		struct pinctrl_gpio_range *range, unsigned offset, bool enable)
308 {
309 	struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
310 	struct spear_pinctrl_machdata *machdata = pmx->machdata;
311 	struct spear_gpio_pingroup *gpio_pingroup;
312 
313 	/*
314 	 * Some SoC have configuration options applicable to group of pins,
315 	 * rather than a single pin.
316 	 */
317 	gpio_pingroup = get_gpio_pingroup(pmx, offset);
318 	if (gpio_pingroup)
319 		muxregs_endisable(pmx, gpio_pingroup->muxregs,
320 				gpio_pingroup->nmuxregs, enable);
321 
322 	/*
323 	 * SoC may need some extra configurations, or configurations for single
324 	 * pin
325 	 */
326 	if (machdata->gpio_request_endisable)
327 		machdata->gpio_request_endisable(pmx, offset, enable);
328 
329 	return 0;
330 }
331 
332 static int gpio_request_enable(struct pinctrl_dev *pctldev,
333 		struct pinctrl_gpio_range *range, unsigned offset)
334 {
335 	return gpio_request_endisable(pctldev, range, offset, true);
336 }
337 
338 static void gpio_disable_free(struct pinctrl_dev *pctldev,
339 		struct pinctrl_gpio_range *range, unsigned offset)
340 {
341 	gpio_request_endisable(pctldev, range, offset, false);
342 }
343 
344 static const struct pinmux_ops spear_pinmux_ops = {
345 	.get_functions_count = spear_pinctrl_get_funcs_count,
346 	.get_function_name = spear_pinctrl_get_func_name,
347 	.get_function_groups = spear_pinctrl_get_func_groups,
348 	.set_mux = spear_pinctrl_set_mux,
349 	.gpio_request_enable = gpio_request_enable,
350 	.gpio_disable_free = gpio_disable_free,
351 };
352 
353 static struct pinctrl_desc spear_pinctrl_desc = {
354 	.name = DRIVER_NAME,
355 	.pctlops = &spear_pinctrl_ops,
356 	.pmxops = &spear_pinmux_ops,
357 	.owner = THIS_MODULE,
358 };
359 
360 int spear_pinctrl_probe(struct platform_device *pdev,
361 			struct spear_pinctrl_machdata *machdata)
362 {
363 	struct device_node *np = pdev->dev.of_node;
364 	struct spear_pmx *pmx;
365 
366 	if (!machdata)
367 		return -ENODEV;
368 
369 	pmx = devm_kzalloc(&pdev->dev, sizeof(*pmx), GFP_KERNEL);
370 	if (!pmx)
371 		return -ENOMEM;
372 
373 	pmx->regmap = device_node_to_regmap(np);
374 	if (IS_ERR(pmx->regmap)) {
375 		dev_err(&pdev->dev, "Init regmap failed (%pe).\n",
376 			pmx->regmap);
377 		return PTR_ERR(pmx->regmap);
378 	}
379 
380 	pmx->dev = &pdev->dev;
381 	pmx->machdata = machdata;
382 
383 	/* configure mode, if supported by SoC */
384 	if (machdata->modes_supported) {
385 		int mode = 0;
386 
387 		if (of_property_read_u32(np, "st,pinmux-mode", &mode)) {
388 			dev_err(&pdev->dev, "OF: pinmux mode not passed\n");
389 			return -EINVAL;
390 		}
391 
392 		if (set_mode(pmx, mode)) {
393 			dev_err(&pdev->dev, "OF: Couldn't configure mode: %x\n",
394 					mode);
395 			return -EINVAL;
396 		}
397 	}
398 
399 	platform_set_drvdata(pdev, pmx);
400 
401 	spear_pinctrl_desc.pins = machdata->pins;
402 	spear_pinctrl_desc.npins = machdata->npins;
403 
404 	pmx->pctl = devm_pinctrl_register(&pdev->dev, &spear_pinctrl_desc, pmx);
405 	if (IS_ERR(pmx->pctl)) {
406 		dev_err(&pdev->dev, "Couldn't register pinctrl driver\n");
407 		return PTR_ERR(pmx->pctl);
408 	}
409 
410 	return 0;
411 }
412