xref: /openbmc/u-boot/drivers/gpio/xilinx_gpio.c (revision e11ef3d2)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2013 - 2018 Xilinx, Michal Simek
4  */
5 
6 #include <common.h>
7 #include <errno.h>
8 #include <malloc.h>
9 #include <linux/list.h>
10 #include <asm/io.h>
11 #include <asm/gpio.h>
12 #include <dm.h>
13 #include <dt-bindings/gpio/gpio.h>
14 
15 #define XILINX_GPIO_MAX_BANK	2
16 
17 /* Gpio simple map */
18 struct gpio_regs {
19 	u32 gpiodata;
20 	u32 gpiodir;
21 };
22 
23 struct xilinx_gpio_platdata {
24 	struct gpio_regs *regs;
25 	int bank_max[XILINX_GPIO_MAX_BANK];
26 	int bank_input[XILINX_GPIO_MAX_BANK];
27 	int bank_output[XILINX_GPIO_MAX_BANK];
28 	u32 dout_default[XILINX_GPIO_MAX_BANK];
29 };
30 
31 struct xilinx_gpio_privdata {
32 	u32 output_val[XILINX_GPIO_MAX_BANK];
33 };
34 
35 static int xilinx_gpio_get_bank_pin(unsigned offset, u32 *bank_num,
36 				    u32 *bank_pin_num, struct udevice *dev)
37 {
38 	struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
39 	u32 bank, max_pins;
40 	/* the first gpio is 0 not 1 */
41 	u32 pin_num = offset;
42 
43 	for (bank = 0; bank < XILINX_GPIO_MAX_BANK; bank++) {
44 		max_pins = platdata->bank_max[bank];
45 		if (pin_num < max_pins) {
46 			debug("%s: found at bank 0x%x pin 0x%x\n", __func__,
47 			      bank, pin_num);
48 			*bank_num = bank;
49 			*bank_pin_num = pin_num;
50 			return 0;
51 		}
52 		pin_num -= max_pins;
53 	}
54 
55 	return -EINVAL;
56 }
57 
58 static int xilinx_gpio_set_value(struct udevice *dev, unsigned offset,
59 				 int value)
60 {
61 	struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
62 	struct xilinx_gpio_privdata *priv = dev_get_priv(dev);
63 	int val, ret;
64 	u32 bank, pin;
65 
66 	ret = xilinx_gpio_get_bank_pin(offset, &bank, &pin, dev);
67 	if (ret)
68 		return ret;
69 
70 	val = priv->output_val[bank];
71 
72 	debug("%s: regs: %lx, value: %x, gpio: %x, bank %x, pin %x, out %x\n",
73 	      __func__, (ulong)platdata->regs, value, offset, bank, pin, val);
74 
75 	if (value)
76 		val = val | (1 << pin);
77 	else
78 		val = val & ~(1 << pin);
79 
80 	writel(val, &platdata->regs->gpiodata + bank * 2);
81 
82 	priv->output_val[bank] = val;
83 
84 	return 0;
85 };
86 
87 static int xilinx_gpio_get_value(struct udevice *dev, unsigned offset)
88 {
89 	struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
90 	struct xilinx_gpio_privdata *priv = dev_get_priv(dev);
91 	int val, ret;
92 	u32 bank, pin;
93 
94 	ret = xilinx_gpio_get_bank_pin(offset, &bank, &pin, dev);
95 	if (ret)
96 		return ret;
97 
98 	debug("%s: regs: %lx, gpio: %x, bank %x, pin %x\n", __func__,
99 	      (ulong)platdata->regs, offset, bank, pin);
100 
101 	if (platdata->bank_output[bank]) {
102 		debug("%s: Read saved output value\n", __func__);
103 		val = priv->output_val[bank];
104 	} else {
105 		debug("%s: Read input value from reg\n", __func__);
106 		val = readl(&platdata->regs->gpiodata + bank * 2);
107 	}
108 
109 	val = !!(val & (1 << pin));
110 
111 	return val;
112 };
113 
114 static int xilinx_gpio_get_function(struct udevice *dev, unsigned offset)
115 {
116 	struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
117 	int val, ret;
118 	u32 bank, pin;
119 
120 	ret = xilinx_gpio_get_bank_pin(offset, &bank, &pin, dev);
121 	if (ret)
122 		return ret;
123 
124 	/* Check if all pins are inputs */
125 	if (platdata->bank_input[bank])
126 		return GPIOF_INPUT;
127 
128 	/* Check if all pins are outputs */
129 	if (platdata->bank_output[bank])
130 		return GPIOF_OUTPUT;
131 
132 	/* FIXME test on dual */
133 	val = readl(&platdata->regs->gpiodir + bank * 2);
134 	val = !(val & (1 << pin));
135 
136 	/* input is 1 in reg but GPIOF_INPUT is 0 */
137 	/* output is 0 in reg but GPIOF_OUTPUT is 1 */
138 
139 	return val;
140 }
141 
142 static int xilinx_gpio_direction_output(struct udevice *dev, unsigned offset,
143 					int value)
144 {
145 	struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
146 	int val, ret;
147 	u32 bank, pin;
148 
149 	ret = xilinx_gpio_get_bank_pin(offset, &bank, &pin, dev);
150 	if (ret)
151 		return ret;
152 
153 	/* can't change it if all is input by default */
154 	if (platdata->bank_input[bank])
155 		return -EINVAL;
156 
157 	xilinx_gpio_set_value(dev, offset, value);
158 
159 	if (!platdata->bank_output[bank]) {
160 		val = readl(&platdata->regs->gpiodir + bank * 2);
161 		val = val & ~(1 << pin);
162 		writel(val, &platdata->regs->gpiodir + bank * 2);
163 	}
164 
165 	return 0;
166 }
167 
168 static int xilinx_gpio_direction_input(struct udevice *dev, unsigned offset)
169 {
170 	struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
171 	int val, ret;
172 	u32 bank, pin;
173 
174 	ret = xilinx_gpio_get_bank_pin(offset, &bank, &pin, dev);
175 	if (ret)
176 		return ret;
177 
178 	/* Already input */
179 	if (platdata->bank_input[bank])
180 		return 0;
181 
182 	/* can't change it if all is output by default */
183 	if (platdata->bank_output[bank])
184 		return -EINVAL;
185 
186 	val = readl(&platdata->regs->gpiodir + bank * 2);
187 	val = val | (1 << pin);
188 	writel(val, &platdata->regs->gpiodir + bank * 2);
189 
190 	return 0;
191 }
192 
193 static int xilinx_gpio_xlate(struct udevice *dev, struct gpio_desc *desc,
194 			     struct ofnode_phandle_args *args)
195 {
196 	struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
197 
198 	desc->offset = args->args[0];
199 
200 	debug("%s: argc: %x, [0]: %x, [1]: %x, [2]: %x\n", __func__,
201 	      args->args_count, args->args[0], args->args[1], args->args[2]);
202 
203 	/*
204 	 * The second cell is channel offset:
205 	 *  0 is first channel, 8 is second channel
206 	 *
207 	 * U-Boot driver just combine channels together that's why simply
208 	 * add amount of pins in second channel if present.
209 	 */
210 	if (args->args[1]) {
211 		if (!platdata->bank_max[1]) {
212 			printf("%s: %s has no second channel\n",
213 			       __func__, dev->name);
214 			return -EINVAL;
215 		}
216 
217 		desc->offset += platdata->bank_max[0];
218 	}
219 
220 	/* The third cell is optional */
221 	if (args->args_count > 2)
222 		desc->flags = (args->args[2] &
223 			       GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0);
224 
225 	debug("%s: offset %x, flags %lx\n",
226 	      __func__, desc->offset, desc->flags);
227 	return 0;
228 }
229 
230 static const struct dm_gpio_ops xilinx_gpio_ops = {
231 	.direction_input = xilinx_gpio_direction_input,
232 	.direction_output = xilinx_gpio_direction_output,
233 	.get_value = xilinx_gpio_get_value,
234 	.set_value = xilinx_gpio_set_value,
235 	.get_function = xilinx_gpio_get_function,
236 	.xlate = xilinx_gpio_xlate,
237 };
238 
239 static int xilinx_gpio_probe(struct udevice *dev)
240 {
241 	struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
242 	struct xilinx_gpio_privdata *priv = dev_get_priv(dev);
243 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
244 	const void *label_ptr;
245 
246 	label_ptr = dev_read_prop(dev, "label", NULL);
247 	if (label_ptr) {
248 		uc_priv->bank_name = strdup(label_ptr);
249 		if (!uc_priv->bank_name)
250 			return -ENOMEM;
251 	} else {
252 		uc_priv->bank_name = dev->name;
253 	}
254 
255 	uc_priv->gpio_count = platdata->bank_max[0] + platdata->bank_max[1];
256 
257 	priv->output_val[0] = platdata->dout_default[0];
258 
259 	if (platdata->bank_max[1])
260 		priv->output_val[1] = platdata->dout_default[1];
261 
262 	return 0;
263 }
264 
265 static int xilinx_gpio_ofdata_to_platdata(struct udevice *dev)
266 {
267 	struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev);
268 	int is_dual;
269 
270 	platdata->regs = (struct gpio_regs *)dev_read_addr(dev);
271 
272 	platdata->bank_max[0] = dev_read_u32_default(dev,
273 						     "xlnx,gpio-width", 0);
274 	platdata->bank_input[0] = dev_read_u32_default(dev,
275 						       "xlnx,all-inputs", 0);
276 	platdata->bank_output[0] = dev_read_u32_default(dev,
277 							"xlnx,all-outputs", 0);
278 	platdata->dout_default[0] = dev_read_u32_default(dev,
279 							 "xlnx,dout-default",
280 							 0);
281 
282 	is_dual = dev_read_u32_default(dev, "xlnx,is-dual", 0);
283 	if (is_dual) {
284 		platdata->bank_max[1] = dev_read_u32_default(dev,
285 						"xlnx,gpio2-width", 0);
286 		platdata->bank_input[1] = dev_read_u32_default(dev,
287 						"xlnx,all-inputs-2", 0);
288 		platdata->bank_output[1] = dev_read_u32_default(dev,
289 						"xlnx,all-outputs-2", 0);
290 		platdata->dout_default[1] = dev_read_u32_default(dev,
291 						"xlnx,dout-default-2", 0);
292 	}
293 
294 	return 0;
295 }
296 
297 static const struct udevice_id xilinx_gpio_ids[] = {
298 	{ .compatible = "xlnx,xps-gpio-1.00.a",},
299 	{ }
300 };
301 
302 U_BOOT_DRIVER(xilinx_gpio) = {
303 	.name = "xlnx_gpio",
304 	.id = UCLASS_GPIO,
305 	.ops = &xilinx_gpio_ops,
306 	.of_match = xilinx_gpio_ids,
307 	.ofdata_to_platdata = xilinx_gpio_ofdata_to_platdata,
308 	.probe = xilinx_gpio_probe,
309 	.platdata_auto_alloc_size = sizeof(struct xilinx_gpio_platdata),
310 	.priv_auto_alloc_size = sizeof(struct xilinx_gpio_privdata),
311 };
312