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