1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Support for viafb GPIO ports.
4 *
5 * Copyright 2009 Jonathan Corbet <corbet@lwn.net>
6 */
7
8#include <linux/spinlock.h>
9#include <linux/gpio/driver.h>
10#include <linux/gpio/machine.h>
11#include <linux/platform_device.h>
12#include <linux/via-core.h>
13#include <linux/export.h>
14#include "via-gpio.h"
15
16/*
17 * The ports we know about. Note that the port-25 gpios are not
18 * mentioned in the datasheet.
19 */
20
21struct viafb_gpio {
22 char *vg_name; /* Data sheet name */
23 u16 vg_io_port;
24 u8 vg_port_index;
25 int vg_mask_shift;
26};
27
28static struct viafb_gpio viafb_all_gpios[] = {
29 {
30 .vg_name = "VGPIO0", /* Guess - not in datasheet */
31 .vg_io_port = VIASR,
32 .vg_port_index = 0x25,
33 .vg_mask_shift = 1
34 },
35 {
36 .vg_name = "VGPIO1",
37 .vg_io_port = VIASR,
38 .vg_port_index = 0x25,
39 .vg_mask_shift = 0
40 },
41 {
42 .vg_name = "VGPIO2", /* aka DISPCLKI0 */
43 .vg_io_port = VIASR,
44 .vg_port_index = 0x2c,
45 .vg_mask_shift = 1
46 },
47 {
48 .vg_name = "VGPIO3", /* aka DISPCLKO0 */
49 .vg_io_port = VIASR,
50 .vg_port_index = 0x2c,
51 .vg_mask_shift = 0
52 },
53 {
54 .vg_name = "VGPIO4", /* DISPCLKI1 */
55 .vg_io_port = VIASR,
56 .vg_port_index = 0x3d,
57 .vg_mask_shift = 1
58 },
59 {
60 .vg_name = "VGPIO5", /* DISPCLKO1 */
61 .vg_io_port = VIASR,
62 .vg_port_index = 0x3d,
63 .vg_mask_shift = 0
64 },
65};
66
67#define VIAFB_NUM_GPIOS ARRAY_SIZE(viafb_all_gpios)
68
69/*
70 * This structure controls the active GPIOs, which may be a subset
71 * of those which are known.
72 */
73
74struct viafb_gpio_cfg {
75 struct gpio_chip gpio_chip;
76 struct viafb_dev *vdev;
77 struct viafb_gpio *active_gpios[VIAFB_NUM_GPIOS];
78 const char *gpio_names[VIAFB_NUM_GPIOS];
79};
80
81/*
82 * GPIO access functions
83 */
84static void via_gpio_set(struct gpio_chip *chip, unsigned int nr,
85 int value)
86{
87 struct viafb_gpio_cfg *cfg = gpiochip_get_data(gc: chip);
88 u8 reg;
89 struct viafb_gpio *gpio;
90 unsigned long flags;
91
92 spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
93 gpio = cfg->active_gpios[nr];
94 reg = via_read_reg(VIASR, index: gpio->vg_port_index);
95 reg |= 0x40 << gpio->vg_mask_shift; /* output enable */
96 if (value)
97 reg |= 0x10 << gpio->vg_mask_shift;
98 else
99 reg &= ~(0x10 << gpio->vg_mask_shift);
100 via_write_reg(VIASR, index: gpio->vg_port_index, data: reg);
101 spin_unlock_irqrestore(lock: &cfg->vdev->reg_lock, flags);
102}
103
104static int via_gpio_dir_out(struct gpio_chip *chip, unsigned int nr,
105 int value)
106{
107 via_gpio_set(chip, nr, value);
108 return 0;
109}
110
111/*
112 * Set the input direction. I'm not sure this is right; we should
113 * be able to do input without disabling output.
114 */
115static int via_gpio_dir_input(struct gpio_chip *chip, unsigned int nr)
116{
117 struct viafb_gpio_cfg *cfg = gpiochip_get_data(gc: chip);
118 struct viafb_gpio *gpio;
119 unsigned long flags;
120
121 spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
122 gpio = cfg->active_gpios[nr];
123 via_write_reg_mask(VIASR, index: gpio->vg_port_index, data: 0,
124 mask: 0x40 << gpio->vg_mask_shift);
125 spin_unlock_irqrestore(lock: &cfg->vdev->reg_lock, flags);
126 return 0;
127}
128
129static int via_gpio_get(struct gpio_chip *chip, unsigned int nr)
130{
131 struct viafb_gpio_cfg *cfg = gpiochip_get_data(gc: chip);
132 u8 reg;
133 struct viafb_gpio *gpio;
134 unsigned long flags;
135
136 spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
137 gpio = cfg->active_gpios[nr];
138 reg = via_read_reg(VIASR, index: gpio->vg_port_index);
139 spin_unlock_irqrestore(lock: &cfg->vdev->reg_lock, flags);
140 return !!(reg & (0x04 << gpio->vg_mask_shift));
141}
142
143
144static struct viafb_gpio_cfg viafb_gpio_config = {
145 .gpio_chip = {
146 .label = "VIAFB onboard GPIO",
147 .owner = THIS_MODULE,
148 .direction_output = via_gpio_dir_out,
149 .set = via_gpio_set,
150 .direction_input = via_gpio_dir_input,
151 .get = via_gpio_get,
152 .base = -1,
153 .ngpio = 0,
154 .can_sleep = 0
155 }
156};
157
158/*
159 * Manage the software enable bit.
160 */
161static void viafb_gpio_enable(struct viafb_gpio *gpio)
162{
163 via_write_reg_mask(VIASR, index: gpio->vg_port_index, data: 0x02, mask: 0x02);
164}
165
166static void viafb_gpio_disable(struct viafb_gpio *gpio)
167{
168 via_write_reg_mask(VIASR, index: gpio->vg_port_index, data: 0, mask: 0x02);
169}
170
171#ifdef CONFIG_PM
172
173static int viafb_gpio_suspend(void *private)
174{
175 return 0;
176}
177
178static int viafb_gpio_resume(void *private)
179{
180 int i;
181
182 for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i += 2)
183 viafb_gpio_enable(gpio: viafb_gpio_config.active_gpios[i]);
184 return 0;
185}
186
187static struct viafb_pm_hooks viafb_gpio_pm_hooks = {
188 .suspend = viafb_gpio_suspend,
189 .resume = viafb_gpio_resume
190};
191#endif /* CONFIG_PM */
192
193static struct gpiod_lookup_table viafb_gpio_table = {
194 .dev_id = "viafb-camera",
195 .table = {
196 GPIO_LOOKUP("via-gpio", 2, "VGPIO2", GPIO_ACTIVE_LOW),
197 GPIO_LOOKUP("via-gpio", 3, "VGPIO3", GPIO_ACTIVE_HIGH),
198 { }
199 },
200};
201
202/*
203 * Platform device stuff.
204 */
205static int viafb_gpio_probe(struct platform_device *platdev)
206{
207 struct viafb_dev *vdev = platdev->dev.platform_data;
208 struct via_port_cfg *port_cfg = vdev->port_cfg;
209 int i, ngpio = 0, ret;
210 struct viafb_gpio *gpio;
211 unsigned long flags;
212
213 /*
214 * Set up entries for all GPIOs which have been configured to
215 * operate as such (as opposed to as i2c ports).
216 */
217 for (i = 0; i < VIAFB_NUM_PORTS; i++) {
218 if (port_cfg[i].mode != VIA_MODE_GPIO)
219 continue;
220 for (gpio = viafb_all_gpios;
221 gpio < viafb_all_gpios + VIAFB_NUM_GPIOS; gpio++)
222 if (gpio->vg_port_index == port_cfg[i].ioport_index) {
223 viafb_gpio_config.active_gpios[ngpio] = gpio;
224 viafb_gpio_config.gpio_names[ngpio] =
225 gpio->vg_name;
226 ngpio++;
227 }
228 }
229 viafb_gpio_config.gpio_chip.ngpio = ngpio;
230 viafb_gpio_config.gpio_chip.names = viafb_gpio_config.gpio_names;
231 viafb_gpio_config.vdev = vdev;
232 if (ngpio == 0) {
233 printk(KERN_INFO "viafb: no GPIOs configured\n");
234 return 0;
235 }
236 /*
237 * Enable the ports. They come in pairs, with a single
238 * enable bit for both.
239 */
240 spin_lock_irqsave(&viafb_gpio_config.vdev->reg_lock, flags);
241 for (i = 0; i < ngpio; i += 2)
242 viafb_gpio_enable(gpio: viafb_gpio_config.active_gpios[i]);
243 spin_unlock_irqrestore(lock: &viafb_gpio_config.vdev->reg_lock, flags);
244 /*
245 * Get registered.
246 */
247 viafb_gpio_config.gpio_chip.base = -1; /* Dynamic */
248 viafb_gpio_config.gpio_chip.label = "via-gpio";
249 ret = gpiochip_add_data(&viafb_gpio_config.gpio_chip,
250 &viafb_gpio_config);
251 if (ret) {
252 printk(KERN_ERR "viafb: failed to add gpios (%d)\n", ret);
253 viafb_gpio_config.gpio_chip.ngpio = 0;
254 }
255
256 gpiod_add_lookup_table(table: &viafb_gpio_table);
257
258#ifdef CONFIG_PM
259 viafb_pm_register(hooks: &viafb_gpio_pm_hooks);
260#endif
261 return ret;
262}
263
264
265static void viafb_gpio_remove(struct platform_device *platdev)
266{
267 unsigned long flags;
268 int i;
269
270#ifdef CONFIG_PM
271 viafb_pm_unregister(hooks: &viafb_gpio_pm_hooks);
272#endif
273
274 /*
275 * Get unregistered.
276 */
277 if (viafb_gpio_config.gpio_chip.ngpio > 0) {
278 gpiochip_remove(gc: &viafb_gpio_config.gpio_chip);
279 }
280 /*
281 * Disable the ports.
282 */
283 spin_lock_irqsave(&viafb_gpio_config.vdev->reg_lock, flags);
284 for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i += 2)
285 viafb_gpio_disable(gpio: viafb_gpio_config.active_gpios[i]);
286 viafb_gpio_config.gpio_chip.ngpio = 0;
287 spin_unlock_irqrestore(lock: &viafb_gpio_config.vdev->reg_lock, flags);
288}
289
290static struct platform_driver via_gpio_driver = {
291 .driver = {
292 .name = "viafb-gpio",
293 },
294 .probe = viafb_gpio_probe,
295 .remove_new = viafb_gpio_remove,
296};
297
298int viafb_gpio_init(void)
299{
300 return platform_driver_register(&via_gpio_driver);
301}
302
303void viafb_gpio_exit(void)
304{
305 platform_driver_unregister(&via_gpio_driver);
306}
307

source code of linux/drivers/video/fbdev/via/via-gpio.c