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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Xilinx gpio driver for xps/axi_gpio IP.
4 *
5 * Copyright 2008 - 2013 Xilinx, Inc.
6 */
7
8#include <linux/bitops.h>
9#include <linux/init.h>
10#include <linux/errno.h>
11#include <linux/module.h>
12#include <linux/of_device.h>
13#include <linux/of_platform.h>
14#include <linux/io.h>
15#include <linux/gpio/driver.h>
16#include <linux/slab.h>
17
18/* Register Offset Definitions */
19#define XGPIO_DATA_OFFSET (0x0) /* Data register */
20#define XGPIO_TRI_OFFSET (0x4) /* I/O direction register */
21
22#define XGPIO_CHANNEL_OFFSET 0x8
23
24/* Read/Write access to the GPIO registers */
25#if defined(CONFIG_ARCH_ZYNQ) || defined(CONFIG_X86)
26# define xgpio_readreg(offset) readl(offset)
27# define xgpio_writereg(offset, val) writel(val, offset)
28#else
29# define xgpio_readreg(offset) __raw_readl(offset)
30# define xgpio_writereg(offset, val) __raw_writel(val, offset)
31#endif
32
33/**
34 * struct xgpio_instance - Stores information about GPIO device
35 * @gc: GPIO chip
36 * @regs: register block
37 * @gpio_width: GPIO width for every channel
38 * @gpio_state: GPIO state shadow register
39 * @gpio_dir: GPIO direction shadow register
40 * @gpio_lock: Lock used for synchronization
41 */
42struct xgpio_instance {
43 struct gpio_chip gc;
44 void __iomem *regs;
45 unsigned int gpio_width[2];
46 u32 gpio_state[2];
47 u32 gpio_dir[2];
48 spinlock_t gpio_lock[2];
49};
50
51static inline int xgpio_index(struct xgpio_instance *chip, int gpio)
52{
53 if (gpio >= chip->gpio_width[0])
54 return 1;
55
56 return 0;
57}
58
59static inline int xgpio_regoffset(struct xgpio_instance *chip, int gpio)
60{
61 if (xgpio_index(chip, gpio))
62 return XGPIO_CHANNEL_OFFSET;
63
64 return 0;
65}
66
67static inline int xgpio_offset(struct xgpio_instance *chip, int gpio)
68{
69 if (xgpio_index(chip, gpio))
70 return gpio - chip->gpio_width[0];
71
72 return gpio;
73}
74
75/**
76 * xgpio_get - Read the specified signal of the GPIO device.
77 * @gc: Pointer to gpio_chip device structure.
78 * @gpio: GPIO signal number.
79 *
80 * This function reads the specified signal of the GPIO device.
81 *
82 * Return:
83 * 0 if direction of GPIO signals is set as input otherwise it
84 * returns negative error value.
85 */
86static int xgpio_get(struct gpio_chip *gc, unsigned int gpio)
87{
88 struct xgpio_instance *chip = gpiochip_get_data(gc);
89 u32 val;
90
91 val = xgpio_readreg(chip->regs + XGPIO_DATA_OFFSET +
92 xgpio_regoffset(chip, gpio));
93
94 return !!(val & BIT(xgpio_offset(chip, gpio)));
95}
96
97/**
98 * xgpio_set - Write the specified signal of the GPIO device.
99 * @gc: Pointer to gpio_chip device structure.
100 * @gpio: GPIO signal number.
101 * @val: Value to be written to specified signal.
102 *
103 * This function writes the specified value in to the specified signal of the
104 * GPIO device.
105 */
106static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
107{
108 unsigned long flags;
109 struct xgpio_instance *chip = gpiochip_get_data(gc);
110 int index = xgpio_index(chip, gpio);
111 int offset = xgpio_offset(chip, gpio);
112
113 spin_lock_irqsave(&chip->gpio_lock[index], flags);
114
115 /* Write to GPIO signal and set its direction to output */
116 if (val)
117 chip->gpio_state[index] |= BIT(offset);
118 else
119 chip->gpio_state[index] &= ~BIT(offset);
120
121 xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
122 xgpio_regoffset(chip, gpio), chip->gpio_state[index]);
123
124 spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
125}
126
127/**
128 * xgpio_set_multiple - Write the specified signals of the GPIO device.
129 * @gc: Pointer to gpio_chip device structure.
130 * @mask: Mask of the GPIOS to modify.
131 * @bits: Value to be wrote on each GPIO
132 *
133 * This function writes the specified values into the specified signals of the
134 * GPIO devices.
135 */
136static void xgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
137 unsigned long *bits)
138{
139 unsigned long flags;
140 struct xgpio_instance *chip = gpiochip_get_data(gc);
141 int index = xgpio_index(chip, 0);
142 int offset, i;
143
144 spin_lock_irqsave(&chip->gpio_lock[index], flags);
145
146 /* Write to GPIO signals */
147 for (i = 0; i < gc->ngpio; i++) {
148 if (*mask == 0)
149 break;
150 /* Once finished with an index write it out to the register */
151 if (index != xgpio_index(chip, i)) {
152 xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
153 index * XGPIO_CHANNEL_OFFSET,
154 chip->gpio_state[index]);
155 spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
156 index = xgpio_index(chip, i);
157 spin_lock_irqsave(&chip->gpio_lock[index], flags);
158 }
159 if (__test_and_clear_bit(i, mask)) {
160 offset = xgpio_offset(chip, i);
161 if (test_bit(i, bits))
162 chip->gpio_state[index] |= BIT(offset);
163 else
164 chip->gpio_state[index] &= ~BIT(offset);
165 }
166 }
167
168 xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
169 index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);
170
171 spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
172}
173
174/**
175 * xgpio_dir_in - Set the direction of the specified GPIO signal as input.
176 * @gc: Pointer to gpio_chip device structure.
177 * @gpio: GPIO signal number.
178 *
179 * Return:
180 * 0 - if direction of GPIO signals is set as input
181 * otherwise it returns negative error value.
182 */
183static int xgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
184{
185 unsigned long flags;
186 struct xgpio_instance *chip = gpiochip_get_data(gc);
187 int index = xgpio_index(chip, gpio);
188 int offset = xgpio_offset(chip, gpio);
189
190 spin_lock_irqsave(&chip->gpio_lock[index], flags);
191
192 /* Set the GPIO bit in shadow register and set direction as input */
193 chip->gpio_dir[index] |= BIT(offset);
194 xgpio_writereg(chip->regs + XGPIO_TRI_OFFSET +
195 xgpio_regoffset(chip, gpio), chip->gpio_dir[index]);
196
197 spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
198
199 return 0;
200}
201
202/**
203 * xgpio_dir_out - Set the direction of the specified GPIO signal as output.
204 * @gc: Pointer to gpio_chip device structure.
205 * @gpio: GPIO signal number.
206 * @val: Value to be written to specified signal.
207 *
208 * This function sets the direction of specified GPIO signal as output.
209 *
210 * Return:
211 * If all GPIO signals of GPIO chip is configured as input then it returns
212 * error otherwise it returns 0.
213 */
214static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
215{
216 unsigned long flags;
217 struct xgpio_instance *chip = gpiochip_get_data(gc);
218 int index = xgpio_index(chip, gpio);
219 int offset = xgpio_offset(chip, gpio);
220
221 spin_lock_irqsave(&chip->gpio_lock[index], flags);
222
223 /* Write state of GPIO signal */
224 if (val)
225 chip->gpio_state[index] |= BIT(offset);
226 else
227 chip->gpio_state[index] &= ~BIT(offset);
228 xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
229 xgpio_regoffset(chip, gpio), chip->gpio_state[index]);
230
231 /* Clear the GPIO bit in shadow register and set direction as output */
232 chip->gpio_dir[index] &= ~BIT(offset);
233 xgpio_writereg(chip->regs + XGPIO_TRI_OFFSET +
234 xgpio_regoffset(chip, gpio), chip->gpio_dir[index]);
235
236 spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
237
238 return 0;
239}
240
241/**
242 * xgpio_save_regs - Set initial values of GPIO pins
243 * @chip: Pointer to GPIO instance
244 */
245static void xgpio_save_regs(struct xgpio_instance *chip)
246{
247 xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET, chip->gpio_state[0]);
248 xgpio_writereg(chip->regs + XGPIO_TRI_OFFSET, chip->gpio_dir[0]);
249
250 if (!chip->gpio_width[1])
251 return;
252
253 xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET + XGPIO_CHANNEL_OFFSET,
254 chip->gpio_state[1]);
255 xgpio_writereg(chip->regs + XGPIO_TRI_OFFSET + XGPIO_CHANNEL_OFFSET,
256 chip->gpio_dir[1]);
257}
258
259/**
260 * xgpio_of_probe - Probe method for the GPIO device.
261 * @pdev: pointer to the platform device
262 *
263 * Return:
264 * It returns 0, if the driver is bound to the GPIO device, or
265 * a negative value if there is an error.
266 */
267static int xgpio_probe(struct platform_device *pdev)
268{
269 struct xgpio_instance *chip;
270 int status = 0;
271 struct device_node *np = pdev->dev.of_node;
272 u32 is_dual;
273
274 chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
275 if (!chip)
276 return -ENOMEM;
277
278 platform_set_drvdata(pdev, chip);
279
280 /* Update GPIO state shadow register with default value */
281 of_property_read_u32(np, "xlnx,dout-default", &chip->gpio_state[0]);
282
283 /* Update GPIO direction shadow register with default value */
284 if (of_property_read_u32(np, "xlnx,tri-default", &chip->gpio_dir[0]))
285 chip->gpio_dir[0] = 0xFFFFFFFF;
286
287 /*
288 * Check device node and parent device node for device width
289 * and assume default width of 32
290 */
291 if (of_property_read_u32(np, "xlnx,gpio-width", &chip->gpio_width[0]))
292 chip->gpio_width[0] = 32;
293
294 spin_lock_init(&chip->gpio_lock[0]);
295
296 if (of_property_read_u32(np, "xlnx,is-dual", &is_dual))
297 is_dual = 0;
298
299 if (is_dual) {
300 /* Update GPIO state shadow register with default value */
301 of_property_read_u32(np, "xlnx,dout-default-2",
302 &chip->gpio_state[1]);
303
304 /* Update GPIO direction shadow register with default value */
305 if (of_property_read_u32(np, "xlnx,tri-default-2",
306 &chip->gpio_dir[1]))
307 chip->gpio_dir[1] = 0xFFFFFFFF;
308
309 /*
310 * Check device node and parent device node for device width
311 * and assume default width of 32
312 */
313 if (of_property_read_u32(np, "xlnx,gpio2-width",
314 &chip->gpio_width[1]))
315 chip->gpio_width[1] = 32;
316
317 spin_lock_init(&chip->gpio_lock[1]);
318 }
319
320 chip->gc.base = -1;
321 chip->gc.ngpio = chip->gpio_width[0] + chip->gpio_width[1];
322 chip->gc.parent = &pdev->dev;
323 chip->gc.direction_input = xgpio_dir_in;
324 chip->gc.direction_output = xgpio_dir_out;
325 chip->gc.get = xgpio_get;
326 chip->gc.set = xgpio_set;
327 chip->gc.set_multiple = xgpio_set_multiple;
328
329 chip->gc.label = dev_name(&pdev->dev);
330
331 chip->regs = devm_platform_ioremap_resource(pdev, 0);
332 if (IS_ERR(chip->regs)) {
333 dev_err(&pdev->dev, "failed to ioremap memory resource\n");
334 return PTR_ERR(chip->regs);
335 }
336
337 xgpio_save_regs(chip);
338
339 status = devm_gpiochip_add_data(&pdev->dev, &chip->gc, chip);
340 if (status) {
341 dev_err(&pdev->dev, "failed to add GPIO chip\n");
342 return status;
343 }
344
345 return 0;
346}
347
348static const struct of_device_id xgpio_of_match[] = {
349 { .compatible = "xlnx,xps-gpio-1.00.a", },
350 { /* end of list */ },
351};
352
353MODULE_DEVICE_TABLE(of, xgpio_of_match);
354
355static struct platform_driver xgpio_plat_driver = {
356 .probe = xgpio_probe,
357 .driver = {
358 .name = "gpio-xilinx",
359 .of_match_table = xgpio_of_match,
360 },
361};
362
363static int __init xgpio_init(void)
364{
365 return platform_driver_register(&xgpio_plat_driver);
366}
367
368subsys_initcall(xgpio_init);
369
370static void __exit xgpio_exit(void)
371{
372 platform_driver_unregister(&xgpio_plat_driver);
373}
374module_exit(xgpio_exit);
375
376MODULE_AUTHOR("Xilinx, Inc.");
377MODULE_DESCRIPTION("Xilinx GPIO driver");
378MODULE_LICENSE("GPL");
1/*
2 * Xilinx gpio driver
3 *
4 * Copyright 2008 Xilinx, Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2
8 * as published by the Free Software Foundation.
9 *
10 * You should have received a copy of the GNU General Public License
11 * along with this program; if not, write to the Free Software
12 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
13 */
14
15#include <linux/init.h>
16#include <linux/errno.h>
17#include <linux/of_device.h>
18#include <linux/of_platform.h>
19#include <linux/of_gpio.h>
20#include <linux/io.h>
21#include <linux/gpio.h>
22#include <linux/slab.h>
23
24/* Register Offset Definitions */
25#define XGPIO_DATA_OFFSET (0x0) /* Data register */
26#define XGPIO_TRI_OFFSET (0x4) /* I/O direction register */
27
28struct xgpio_instance {
29 struct of_mm_gpio_chip mmchip;
30 u32 gpio_state; /* GPIO state shadow register */
31 u32 gpio_dir; /* GPIO direction shadow register */
32 spinlock_t gpio_lock; /* Lock used for synchronization */
33};
34
35/**
36 * xgpio_get - Read the specified signal of the GPIO device.
37 * @gc: Pointer to gpio_chip device structure.
38 * @gpio: GPIO signal number.
39 *
40 * This function reads the specified signal of the GPIO device. It returns 0 if
41 * the signal clear, 1 if signal is set or negative value on error.
42 */
43static int xgpio_get(struct gpio_chip *gc, unsigned int gpio)
44{
45 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
46
47 return (in_be32(mm_gc->regs + XGPIO_DATA_OFFSET) >> gpio) & 1;
48}
49
50/**
51 * xgpio_set - Write the specified signal of the GPIO device.
52 * @gc: Pointer to gpio_chip device structure.
53 * @gpio: GPIO signal number.
54 * @val: Value to be written to specified signal.
55 *
56 * This function writes the specified value in to the specified signal of the
57 * GPIO device.
58 */
59static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
60{
61 unsigned long flags;
62 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
63 struct xgpio_instance *chip =
64 container_of(mm_gc, struct xgpio_instance, mmchip);
65
66 spin_lock_irqsave(&chip->gpio_lock, flags);
67
68 /* Write to GPIO signal and set its direction to output */
69 if (val)
70 chip->gpio_state |= 1 << gpio;
71 else
72 chip->gpio_state &= ~(1 << gpio);
73 out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
74
75 spin_unlock_irqrestore(&chip->gpio_lock, flags);
76}
77
78/**
79 * xgpio_dir_in - Set the direction of the specified GPIO signal as input.
80 * @gc: Pointer to gpio_chip device structure.
81 * @gpio: GPIO signal number.
82 *
83 * This function sets the direction of specified GPIO signal as input.
84 * It returns 0 if direction of GPIO signals is set as input otherwise it
85 * returns negative error value.
86 */
87static int xgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
88{
89 unsigned long flags;
90 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
91 struct xgpio_instance *chip =
92 container_of(mm_gc, struct xgpio_instance, mmchip);
93
94 spin_lock_irqsave(&chip->gpio_lock, flags);
95
96 /* Set the GPIO bit in shadow register and set direction as input */
97 chip->gpio_dir |= (1 << gpio);
98 out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
99
100 spin_unlock_irqrestore(&chip->gpio_lock, flags);
101
102 return 0;
103}
104
105/**
106 * xgpio_dir_out - Set the direction of the specified GPIO signal as output.
107 * @gc: Pointer to gpio_chip device structure.
108 * @gpio: GPIO signal number.
109 * @val: Value to be written to specified signal.
110 *
111 * This function sets the direction of specified GPIO signal as output. If all
112 * GPIO signals of GPIO chip is configured as input then it returns
113 * error otherwise it returns 0.
114 */
115static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
116{
117 unsigned long flags;
118 struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
119 struct xgpio_instance *chip =
120 container_of(mm_gc, struct xgpio_instance, mmchip);
121
122 spin_lock_irqsave(&chip->gpio_lock, flags);
123
124 /* Write state of GPIO signal */
125 if (val)
126 chip->gpio_state |= 1 << gpio;
127 else
128 chip->gpio_state &= ~(1 << gpio);
129 out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
130
131 /* Clear the GPIO bit in shadow register and set direction as output */
132 chip->gpio_dir &= (~(1 << gpio));
133 out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
134
135 spin_unlock_irqrestore(&chip->gpio_lock, flags);
136
137 return 0;
138}
139
140/**
141 * xgpio_save_regs - Set initial values of GPIO pins
142 * @mm_gc: pointer to memory mapped GPIO chip structure
143 */
144static void xgpio_save_regs(struct of_mm_gpio_chip *mm_gc)
145{
146 struct xgpio_instance *chip =
147 container_of(mm_gc, struct xgpio_instance, mmchip);
148
149 out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
150 out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
151}
152
153/**
154 * xgpio_of_probe - Probe method for the GPIO device.
155 * @np: pointer to device tree node
156 *
157 * This function probes the GPIO device in the device tree. It initializes the
158 * driver data structure. It returns 0, if the driver is bound to the GPIO
159 * device, or a negative value if there is an error.
160 */
161static int __devinit xgpio_of_probe(struct device_node *np)
162{
163 struct xgpio_instance *chip;
164 int status = 0;
165 const u32 *tree_info;
166
167 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
168 if (!chip)
169 return -ENOMEM;
170
171 /* Update GPIO state shadow register with default value */
172 tree_info = of_get_property(np, "xlnx,dout-default", NULL);
173 if (tree_info)
174 chip->gpio_state = be32_to_cpup(tree_info);
175
176 /* Update GPIO direction shadow register with default value */
177 chip->gpio_dir = 0xFFFFFFFF; /* By default, all pins are inputs */
178 tree_info = of_get_property(np, "xlnx,tri-default", NULL);
179 if (tree_info)
180 chip->gpio_dir = be32_to_cpup(tree_info);
181
182 /* Check device node and parent device node for device width */
183 chip->mmchip.gc.ngpio = 32; /* By default assume full GPIO controller */
184 tree_info = of_get_property(np, "xlnx,gpio-width", NULL);
185 if (!tree_info)
186 tree_info = of_get_property(np->parent,
187 "xlnx,gpio-width", NULL);
188 if (tree_info)
189 chip->mmchip.gc.ngpio = be32_to_cpup(tree_info);
190
191 spin_lock_init(&chip->gpio_lock);
192
193 chip->mmchip.gc.direction_input = xgpio_dir_in;
194 chip->mmchip.gc.direction_output = xgpio_dir_out;
195 chip->mmchip.gc.get = xgpio_get;
196 chip->mmchip.gc.set = xgpio_set;
197
198 chip->mmchip.save_regs = xgpio_save_regs;
199
200 /* Call the OF gpio helper to setup and register the GPIO device */
201 status = of_mm_gpiochip_add(np, &chip->mmchip);
202 if (status) {
203 kfree(chip);
204 pr_err("%s: error in probe function with status %d\n",
205 np->full_name, status);
206 return status;
207 }
208 pr_info("XGpio: %s: registered\n", np->full_name);
209 return 0;
210}
211
212static struct of_device_id xgpio_of_match[] __devinitdata = {
213 { .compatible = "xlnx,xps-gpio-1.00.a", },
214 { /* end of list */ },
215};
216
217static int __init xgpio_init(void)
218{
219 struct device_node *np;
220
221 for_each_matching_node(np, xgpio_of_match)
222 xgpio_of_probe(np);
223
224 return 0;
225}
226
227/* Make sure we get initialized before anyone else tries to use us */
228subsys_initcall(xgpio_init);
229/* No exit call at the moment as we cannot unregister of GPIO chips */
230
231MODULE_AUTHOR("Xilinx, Inc.");
232MODULE_DESCRIPTION("Xilinx GPIO driver");
233MODULE_LICENSE("GPL");