1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2020 Sean Anderson <seanga2@gmail.com>
4  * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <dm/pinctrl.h>
10 #include <dt-bindings/pinctrl/sandbox-pinmux.h>
11 #include <log.h>
12 #include <linux/bitops.h>
13 
14 /*
15  * This driver emulates a pin controller with the following rules:
16  * - The pinctrl config for each pin must be set individually
17  * - The first three pins (P0-P2) must be muxed as a group
18  * - The next two pins (P3-P4) must be muxed as a group
19  * - The last four pins (P5-P8) must be muxed individually
20  */
21 
22 static const char * const sandbox_pins[] = {
23 #define PIN(x) \
24 	[x] = "P" #x
25 	PIN(0),
26 	PIN(1),
27 	PIN(2),
28 	PIN(3),
29 	PIN(4),
30 	PIN(5),
31 	PIN(6),
32 	PIN(7),
33 	PIN(8),
34 #undef PIN
35 };
36 
37 static const char * const sandbox_pins_muxing[][2] = {
38 	{ "UART TX", "I2C SCL" },
39 	{ "UART RX", "I2C SDA" },
40 	{ "SPI SCLK", "I2S SCK" },
41 	{ "SPI MOSI", "I2S SD" },
42 	{ "SPI MISO", "I2S WS" },
43 	{ "GPIO0", "SPI CS0" },
44 	{ "GPIO1", "SPI CS1" },
45 	{ "GPIO2", "PWM0" },
46 	{ "GPIO3", "PWM1" },
47 };
48 
49 #define SANDBOX_GROUP_I2C_UART 0
50 #define SANDBOX_GROUP_SPI_I2S 1
51 
52 static const char * const sandbox_groups[] = {
53 	[SANDBOX_GROUP_I2C_UART] = "I2C_UART",
54 	[SANDBOX_GROUP_SPI_I2S] = "SPI_I2S",
55 };
56 
57 static const char * const sandbox_functions[] = {
58 #define FUNC(id) \
59 	[SANDBOX_PINMUX_##id] = #id
60 	FUNC(UART),
61 	FUNC(I2C),
62 	FUNC(SPI),
63 	FUNC(I2S),
64 	FUNC(GPIO),
65 	FUNC(CS),
66 	FUNC(PWM),
67 #undef FUNC
68 };
69 
70 static const struct pinconf_param sandbox_conf_params[] = {
71 	{ "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
72 	{ "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
73 	{ "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
74 	{ "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
75 	{ "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
76 	{ "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
77 	{ "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
78 	{ "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
79 	{ "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
80 	{ "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
81 	{ "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
82 };
83 
84 /* Bitfield used to save param and value of each pin/selector */
85 struct sandbox_pinctrl_priv {
86 	unsigned int mux;
87 	unsigned int pins_param[ARRAY_SIZE(sandbox_pins)];
88 	unsigned int pins_value[ARRAY_SIZE(sandbox_pins)];
89 };
90 
sandbox_get_pins_count(struct udevice * dev)91 static int sandbox_get_pins_count(struct udevice *dev)
92 {
93 	return ARRAY_SIZE(sandbox_pins);
94 }
95 
sandbox_get_pin_name(struct udevice * dev,unsigned selector)96 static const char *sandbox_get_pin_name(struct udevice *dev, unsigned selector)
97 {
98 	return sandbox_pins[selector];
99 }
100 
sandbox_get_pin_muxing(struct udevice * dev,unsigned int selector,char * buf,int size)101 static int sandbox_get_pin_muxing(struct udevice *dev,
102 				  unsigned int selector,
103 				  char *buf, int size)
104 {
105 	const struct pinconf_param *p;
106 	struct sandbox_pinctrl_priv *priv = dev_get_priv(dev);
107 	int i;
108 
109 	snprintf(buf, size, "%s",
110 		 sandbox_pins_muxing[selector][!!(priv->mux & BIT(selector))]);
111 
112 	if (priv->pins_param[selector]) {
113 		for (i = 0, p = sandbox_conf_params;
114 		     i < ARRAY_SIZE(sandbox_conf_params);
115 		     i++, p++) {
116 			if ((priv->pins_param[selector] & BIT(p->param)) &&
117 			    (!!(priv->pins_value[selector] & BIT(p->param)) ==
118 			     p->default_value)) {
119 				strncat(buf, " ", size);
120 				strncat(buf, p->property, size);
121 			}
122 		}
123 	}
124 	strncat(buf, ".", size);
125 
126 	return 0;
127 }
128 
sandbox_get_groups_count(struct udevice * dev)129 static int sandbox_get_groups_count(struct udevice *dev)
130 {
131 	return ARRAY_SIZE(sandbox_groups);
132 }
133 
sandbox_get_group_name(struct udevice * dev,unsigned selector)134 static const char *sandbox_get_group_name(struct udevice *dev,
135 					  unsigned selector)
136 {
137 	return sandbox_groups[selector];
138 }
139 
sandbox_get_functions_count(struct udevice * dev)140 static int sandbox_get_functions_count(struct udevice *dev)
141 {
142 	return ARRAY_SIZE(sandbox_functions);
143 }
144 
sandbox_get_function_name(struct udevice * dev,unsigned selector)145 static const char *sandbox_get_function_name(struct udevice *dev,
146 					     unsigned selector)
147 {
148 	return sandbox_functions[selector];
149 }
150 
sandbox_pinmux_set(struct udevice * dev,unsigned pin_selector,unsigned func_selector)151 static int sandbox_pinmux_set(struct udevice *dev, unsigned pin_selector,
152 			      unsigned func_selector)
153 {
154 	int mux;
155 	struct sandbox_pinctrl_priv *priv = dev_get_priv(dev);
156 
157 	debug("sandbox pinmux: pin = %d (%s), function = %d (%s)\n",
158 	      pin_selector, sandbox_get_pin_name(dev, pin_selector),
159 	      func_selector, sandbox_get_function_name(dev, func_selector));
160 
161 	if (pin_selector < 5)
162 		return -EINVAL;
163 
164 	switch (func_selector) {
165 	case SANDBOX_PINMUX_GPIO:
166 		mux = 0;
167 		break;
168 	case SANDBOX_PINMUX_CS:
169 	case SANDBOX_PINMUX_PWM:
170 		mux = BIT(pin_selector);
171 		break;
172 	default:
173 		return -EINVAL;
174 	}
175 
176 	priv->mux &= ~BIT(pin_selector);
177 	priv->mux |= mux;
178 	priv->pins_param[pin_selector] = 0;
179 	priv->pins_value[pin_selector] = 0;
180 
181 	return 0;
182 }
183 
sandbox_pinmux_group_set(struct udevice * dev,unsigned group_selector,unsigned func_selector)184 static int sandbox_pinmux_group_set(struct udevice *dev,
185 				    unsigned group_selector,
186 				    unsigned func_selector)
187 {
188 	bool mux;
189 	int i, group_start, group_end;
190 	struct sandbox_pinctrl_priv *priv = dev_get_priv(dev);
191 	unsigned int mask;
192 
193 	debug("sandbox pinmux: group = %d (%s), function = %d (%s)\n",
194 	      group_selector, sandbox_get_group_name(dev, group_selector),
195 	      func_selector, sandbox_get_function_name(dev, func_selector));
196 
197 	if (group_selector == SANDBOX_GROUP_I2C_UART) {
198 		group_start = 0;
199 		group_end = 1;
200 
201 		if (func_selector == SANDBOX_PINMUX_UART)
202 			mux = false;
203 		else if (func_selector == SANDBOX_PINMUX_I2C)
204 			mux = true;
205 		else
206 			return -EINVAL;
207 	} else if (group_selector == SANDBOX_GROUP_SPI_I2S) {
208 		group_start = 2;
209 		group_end = 4;
210 
211 		if (func_selector == SANDBOX_PINMUX_SPI)
212 			mux = false;
213 		else if (func_selector == SANDBOX_PINMUX_I2S)
214 			mux = true;
215 		else
216 			return -EINVAL;
217 	} else {
218 		return -EINVAL;
219 	}
220 
221 	mask = GENMASK(group_end, group_start);
222 	priv->mux &= ~mask;
223 	priv->mux |= mux ? mask : 0;
224 
225 	for (i = group_start; i < group_end; i++) {
226 		priv->pins_param[i] = 0;
227 		priv->pins_value[i] = 0;
228 	}
229 
230 	return 0;
231 }
232 
sandbox_pinmux_property_set(struct udevice * dev,u32 pinmux_group)233 static int sandbox_pinmux_property_set(struct udevice *dev, u32 pinmux_group)
234 {
235 	int ret;
236 	unsigned pin_selector = pinmux_group & 0xFFFF;
237 	unsigned func_selector = pinmux_group >> 16;
238 
239 	ret = sandbox_pinmux_set(dev, pin_selector, func_selector);
240 	return ret ? ret : pin_selector;
241 }
242 
sandbox_pinconf_set(struct udevice * dev,unsigned pin_selector,unsigned param,unsigned argument)243 static int sandbox_pinconf_set(struct udevice *dev, unsigned pin_selector,
244 			       unsigned param, unsigned argument)
245 {
246 	struct sandbox_pinctrl_priv *priv = dev_get_priv(dev);
247 
248 	debug("sandbox pinconf: pin = %d (%s), param = %d, arg = %d\n",
249 	      pin_selector, sandbox_get_pin_name(dev, pin_selector),
250 	      param, argument);
251 
252 	priv->pins_param[pin_selector] |= BIT(param);
253 	if (argument)
254 		priv->pins_value[pin_selector] |= BIT(param);
255 	else
256 		priv->pins_value[pin_selector] &= ~BIT(param);
257 
258 	return 0;
259 }
260 
sandbox_pinconf_group_set(struct udevice * dev,unsigned group_selector,unsigned param,unsigned argument)261 static int sandbox_pinconf_group_set(struct udevice *dev,
262 				     unsigned group_selector,
263 				     unsigned param, unsigned argument)
264 {
265 	debug("sandbox pinconf: group = %d (%s), param = %d, arg = %d\n",
266 	      group_selector, sandbox_get_group_name(dev, group_selector),
267 	      param, argument);
268 
269 	return 0;
270 }
271 
272 const struct pinctrl_ops sandbox_pinctrl_ops = {
273 	.get_pins_count = sandbox_get_pins_count,
274 	.get_pin_name = sandbox_get_pin_name,
275 	.get_pin_muxing = sandbox_get_pin_muxing,
276 	.get_groups_count = sandbox_get_groups_count,
277 	.get_group_name = sandbox_get_group_name,
278 	.get_functions_count = sandbox_get_functions_count,
279 	.get_function_name = sandbox_get_function_name,
280 	.pinmux_set = sandbox_pinmux_set,
281 	.pinmux_group_set = sandbox_pinmux_group_set,
282 	.pinmux_property_set = sandbox_pinmux_property_set,
283 	.pinconf_num_params = ARRAY_SIZE(sandbox_conf_params),
284 	.pinconf_params = sandbox_conf_params,
285 	.pinconf_set = sandbox_pinconf_set,
286 	.pinconf_group_set = sandbox_pinconf_group_set,
287 	.set_state = pinctrl_generic_set_state,
288 };
289 
290 static const struct udevice_id sandbox_pinctrl_match[] = {
291 	{ .compatible = "sandbox,pinctrl" },
292 	{ /* sentinel */ }
293 };
294 
295 U_BOOT_DRIVER(sandbox_pinctrl) = {
296 	.name = "sandbox_pinctrl",
297 	.id = UCLASS_PINCTRL,
298 	.of_match = sandbox_pinctrl_match,
299 	.priv_auto	= sizeof(struct sandbox_pinctrl_priv),
300 	.ops = &sandbox_pinctrl_ops,
301 };
302