1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright (C) 2013 John Crispin <blogic@openwrt.org>
4  */
5 
6 #include <linux/module.h>
7 #include <linux/device.h>
8 #include <linux/io.h>
9 #include <linux/platform_device.h>
10 #include <linux/slab.h>
11 #include <linux/of.h>
12 #include <linux/pinctrl/pinctrl.h>
13 #include <linux/pinctrl/pinconf.h>
14 #include <linux/pinctrl/pinconf-generic.h>
15 #include <linux/pinctrl/pinmux.h>
16 #include <linux/pinctrl/consumer.h>
17 #include <linux/pinctrl/machine.h>
18 
19 #include <asm/mach-ralink/ralink_regs.h>
20 #include <asm/mach-ralink/mt7620.h>
21 
22 #include "pinctrl-mtmips.h"
23 #include "../core.h"
24 #include "../pinctrl-utils.h"
25 
26 #define SYSC_REG_GPIO_MODE	0x60
27 #define SYSC_REG_GPIO_MODE2	0x64
28 
29 struct mtmips_priv {
30 	struct device *dev;
31 
32 	struct pinctrl_pin_desc *pads;
33 	struct pinctrl_desc *desc;
34 
35 	struct mtmips_pmx_func **func;
36 	int func_count;
37 
38 	struct mtmips_pmx_group *groups;
39 	const char **group_names;
40 	int group_count;
41 
42 	u8 *gpio;
43 	int max_pins;
44 };
45 
46 static int mtmips_get_group_count(struct pinctrl_dev *pctrldev)
47 {
48 	struct mtmips_priv *p = pinctrl_dev_get_drvdata(pctrldev);
49 
50 	return p->group_count;
51 }
52 
53 static const char *mtmips_get_group_name(struct pinctrl_dev *pctrldev,
54 					 unsigned int group)
55 {
56 	struct mtmips_priv *p = pinctrl_dev_get_drvdata(pctrldev);
57 
58 	return (group >= p->group_count) ? NULL : p->group_names[group];
59 }
60 
61 static int mtmips_get_group_pins(struct pinctrl_dev *pctrldev,
62 				 unsigned int group,
63 				 const unsigned int **pins,
64 				 unsigned int *num_pins)
65 {
66 	struct mtmips_priv *p = pinctrl_dev_get_drvdata(pctrldev);
67 
68 	if (group >= p->group_count)
69 		return -EINVAL;
70 
71 	*pins = p->groups[group].func[0].pins;
72 	*num_pins = p->groups[group].func[0].pin_count;
73 
74 	return 0;
75 }
76 
77 static const struct pinctrl_ops mtmips_pctrl_ops = {
78 	.get_groups_count	= mtmips_get_group_count,
79 	.get_group_name		= mtmips_get_group_name,
80 	.get_group_pins		= mtmips_get_group_pins,
81 	.dt_node_to_map		= pinconf_generic_dt_node_to_map_all,
82 	.dt_free_map		= pinconf_generic_dt_free_map,
83 };
84 
85 static int mtmips_pmx_func_count(struct pinctrl_dev *pctrldev)
86 {
87 	struct mtmips_priv *p = pinctrl_dev_get_drvdata(pctrldev);
88 
89 	return p->func_count;
90 }
91 
92 static const char *mtmips_pmx_func_name(struct pinctrl_dev *pctrldev,
93 					unsigned int func)
94 {
95 	struct mtmips_priv *p = pinctrl_dev_get_drvdata(pctrldev);
96 
97 	return p->func[func]->name;
98 }
99 
100 static int mtmips_pmx_group_get_groups(struct pinctrl_dev *pctrldev,
101 				       unsigned int func,
102 				       const char * const **groups,
103 				       unsigned int * const num_groups)
104 {
105 	struct mtmips_priv *p = pinctrl_dev_get_drvdata(pctrldev);
106 
107 	if (p->func[func]->group_count == 1)
108 		*groups = &p->group_names[p->func[func]->groups[0]];
109 	else
110 		*groups = p->group_names;
111 
112 	*num_groups = p->func[func]->group_count;
113 
114 	return 0;
115 }
116 
117 static int mtmips_pmx_group_enable(struct pinctrl_dev *pctrldev,
118 				   unsigned int func, unsigned int group)
119 {
120 	struct mtmips_priv *p = pinctrl_dev_get_drvdata(pctrldev);
121 	u32 mode = 0;
122 	u32 reg = SYSC_REG_GPIO_MODE;
123 	int i;
124 	int shift;
125 
126 	/* dont allow double use */
127 	if (p->groups[group].enabled) {
128 		dev_err(p->dev, "%s is already enabled\n",
129 			p->groups[group].name);
130 		return 0;
131 	}
132 
133 	p->groups[group].enabled = 1;
134 	p->func[func]->enabled = 1;
135 
136 	shift = p->groups[group].shift;
137 	if (shift >= 32) {
138 		shift -= 32;
139 		reg = SYSC_REG_GPIO_MODE2;
140 	}
141 	mode = rt_sysc_r32(reg);
142 	mode &= ~(p->groups[group].mask << shift);
143 
144 	/* mark the pins as gpio */
145 	for (i = 0; i < p->groups[group].func[0].pin_count; i++)
146 		p->gpio[p->groups[group].func[0].pins[i]] = 1;
147 
148 	/* function 0 is gpio and needs special handling */
149 	if (func == 0) {
150 		mode |= p->groups[group].gpio << shift;
151 	} else {
152 		for (i = 0; i < p->func[func]->pin_count; i++)
153 			p->gpio[p->func[func]->pins[i]] = 0;
154 		mode |= p->func[func]->value << shift;
155 	}
156 	rt_sysc_w32(mode, reg);
157 
158 	return 0;
159 }
160 
161 static int mtmips_pmx_group_gpio_request_enable(struct pinctrl_dev *pctrldev,
162 						struct pinctrl_gpio_range *range,
163 						unsigned int pin)
164 {
165 	struct mtmips_priv *p = pinctrl_dev_get_drvdata(pctrldev);
166 
167 	if (!p->gpio[pin]) {
168 		dev_err(p->dev, "pin %d is not set to gpio mux\n", pin);
169 		return -EINVAL;
170 	}
171 
172 	return 0;
173 }
174 
175 static const struct pinmux_ops mtmips_pmx_group_ops = {
176 	.get_functions_count	= mtmips_pmx_func_count,
177 	.get_function_name	= mtmips_pmx_func_name,
178 	.get_function_groups	= mtmips_pmx_group_get_groups,
179 	.set_mux		= mtmips_pmx_group_enable,
180 	.gpio_request_enable	= mtmips_pmx_group_gpio_request_enable,
181 };
182 
183 static struct pinctrl_desc mtmips_pctrl_desc = {
184 	.owner		= THIS_MODULE,
185 	.name		= "mtmips-pinctrl",
186 	.pctlops	= &mtmips_pctrl_ops,
187 	.pmxops		= &mtmips_pmx_group_ops,
188 };
189 
190 static struct mtmips_pmx_func gpio_func = {
191 	.name = "gpio",
192 };
193 
194 static int mtmips_pinctrl_index(struct mtmips_priv *p)
195 {
196 	struct mtmips_pmx_group *mux = p->groups;
197 	int i, j, c = 0;
198 
199 	/* count the mux functions */
200 	while (mux->name) {
201 		p->group_count++;
202 		mux++;
203 	}
204 
205 	/* allocate the group names array needed by the gpio function */
206 	p->group_names = devm_kcalloc(p->dev, p->group_count,
207 				      sizeof(char *), GFP_KERNEL);
208 	if (!p->group_names)
209 		return -ENOMEM;
210 
211 	for (i = 0; i < p->group_count; i++) {
212 		p->group_names[i] = p->groups[i].name;
213 		p->func_count += p->groups[i].func_count;
214 	}
215 
216 	/* we have a dummy function[0] for gpio */
217 	p->func_count++;
218 
219 	/* allocate our function and group mapping index buffers */
220 	p->func = devm_kcalloc(p->dev, p->func_count,
221 			       sizeof(*p->func), GFP_KERNEL);
222 	gpio_func.groups = devm_kcalloc(p->dev, p->group_count, sizeof(int),
223 					GFP_KERNEL);
224 	if (!p->func || !gpio_func.groups)
225 		return -ENOMEM;
226 
227 	/* add a backpointer to the function so it knows its group */
228 	gpio_func.group_count = p->group_count;
229 	for (i = 0; i < gpio_func.group_count; i++)
230 		gpio_func.groups[i] = i;
231 
232 	p->func[c] = &gpio_func;
233 	c++;
234 
235 	/* add remaining functions */
236 	for (i = 0; i < p->group_count; i++) {
237 		for (j = 0; j < p->groups[i].func_count; j++) {
238 			p->func[c] = &p->groups[i].func[j];
239 			p->func[c]->groups = devm_kzalloc(p->dev, sizeof(int),
240 						    GFP_KERNEL);
241 			if (!p->func[c]->groups)
242 				return -ENOMEM;
243 			p->func[c]->groups[0] = i;
244 			p->func[c]->group_count = 1;
245 			c++;
246 		}
247 	}
248 	return 0;
249 }
250 
251 static int mtmips_pinctrl_pins(struct mtmips_priv *p)
252 {
253 	int i, j;
254 
255 	/*
256 	 * loop over the functions and initialize the pins array.
257 	 * also work out the highest pin used.
258 	 */
259 	for (i = 0; i < p->func_count; i++) {
260 		int pin;
261 
262 		if (!p->func[i]->pin_count)
263 			continue;
264 
265 		p->func[i]->pins = devm_kcalloc(p->dev,
266 						p->func[i]->pin_count,
267 						sizeof(int),
268 						GFP_KERNEL);
269 		if (!p->func[i]->pins)
270 			return -ENOMEM;
271 		for (j = 0; j < p->func[i]->pin_count; j++)
272 			p->func[i]->pins[j] = p->func[i]->pin_first + j;
273 
274 		pin = p->func[i]->pin_first + p->func[i]->pin_count;
275 		if (pin > p->max_pins)
276 			p->max_pins = pin;
277 	}
278 
279 	/* the buffer that tells us which pins are gpio */
280 	p->gpio = devm_kcalloc(p->dev, p->max_pins, sizeof(u8), GFP_KERNEL);
281 	/* the pads needed to tell pinctrl about our pins */
282 	p->pads = devm_kcalloc(p->dev, p->max_pins,
283 			       sizeof(struct pinctrl_pin_desc), GFP_KERNEL);
284 	if (!p->pads || !p->gpio)
285 		return -ENOMEM;
286 
287 	memset(p->gpio, 1, sizeof(u8) * p->max_pins);
288 	for (i = 0; i < p->func_count; i++) {
289 		if (!p->func[i]->pin_count)
290 			continue;
291 
292 		for (j = 0; j < p->func[i]->pin_count; j++)
293 			p->gpio[p->func[i]->pins[j]] = 0;
294 	}
295 
296 	/* pin 0 is always a gpio */
297 	p->gpio[0] = 1;
298 
299 	/* set the pads */
300 	for (i = 0; i < p->max_pins; i++) {
301 		/* strlen("ioXY") + 1 = 5 */
302 		char *name = devm_kzalloc(p->dev, 5, GFP_KERNEL);
303 
304 		if (!name)
305 			return -ENOMEM;
306 		snprintf(name, 5, "io%d", i);
307 		p->pads[i].number = i;
308 		p->pads[i].name = name;
309 	}
310 	p->desc->pins = p->pads;
311 	p->desc->npins = p->max_pins;
312 
313 	return 0;
314 }
315 
316 int mtmips_pinctrl_init(struct platform_device *pdev,
317 			struct mtmips_pmx_group *data)
318 {
319 	struct mtmips_priv *p;
320 	struct pinctrl_dev *dev;
321 	int err;
322 
323 	if (!data)
324 		return -ENOTSUPP;
325 
326 	/* setup the private data */
327 	p = devm_kzalloc(&pdev->dev, sizeof(struct mtmips_priv), GFP_KERNEL);
328 	if (!p)
329 		return -ENOMEM;
330 
331 	p->dev = &pdev->dev;
332 	p->desc = &mtmips_pctrl_desc;
333 	p->groups = data;
334 	platform_set_drvdata(pdev, p);
335 
336 	/* init the device */
337 	err = mtmips_pinctrl_index(p);
338 	if (err) {
339 		dev_err(&pdev->dev, "failed to load index\n");
340 		return err;
341 	}
342 
343 	err = mtmips_pinctrl_pins(p);
344 	if (err) {
345 		dev_err(&pdev->dev, "failed to load pins\n");
346 		return err;
347 	}
348 	dev = pinctrl_register(p->desc, &pdev->dev, p);
349 
350 	return PTR_ERR_OR_ZERO(dev);
351 }
352