2 * Support for viafb GPIO ports.
4 * Copyright 2009 Jonathan Corbet <corbet@lwn.net>
5 * Distributable under version 2 of the GNU General Public License.
8 #include <linux/spinlock.h>
9 #include <linux/gpio/driver.h>
10 #include <linux/platform_device.h>
11 #include <linux/via-core.h>
12 #include <linux/via-gpio.h>
13 #include <linux/export.h>
16 * The ports we know about. Note that the port-25 gpios are not
17 * mentioned in the datasheet.
21 char *vg_name; /* Data sheet name */
27 static struct viafb_gpio viafb_all_gpios[] = {
29 .vg_name = "VGPIO0", /* Guess - not in datasheet */
31 .vg_port_index = 0x25,
37 .vg_port_index = 0x25,
41 .vg_name = "VGPIO2", /* aka DISPCLKI0 */
43 .vg_port_index = 0x2c,
47 .vg_name = "VGPIO3", /* aka DISPCLKO0 */
49 .vg_port_index = 0x2c,
53 .vg_name = "VGPIO4", /* DISPCLKI1 */
55 .vg_port_index = 0x3d,
59 .vg_name = "VGPIO5", /* DISPCLKO1 */
61 .vg_port_index = 0x3d,
66 #define VIAFB_NUM_GPIOS ARRAY_SIZE(viafb_all_gpios)
69 * This structure controls the active GPIOs, which may be a subset
70 * of those which are known.
73 struct 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];
81 * GPIO access functions
83 static void via_gpio_set(struct gpio_chip *chip, unsigned int nr,
86 struct viafb_gpio_cfg *cfg = gpiochip_get_data(chip);
88 struct viafb_gpio *gpio;
91 spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
92 gpio = cfg->active_gpios[nr];
93 reg = via_read_reg(VIASR, gpio->vg_port_index);
94 reg |= 0x40 << gpio->vg_mask_shift; /* output enable */
96 reg |= 0x10 << gpio->vg_mask_shift;
98 reg &= ~(0x10 << gpio->vg_mask_shift);
99 via_write_reg(VIASR, gpio->vg_port_index, reg);
100 spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
103 static int via_gpio_dir_out(struct gpio_chip *chip, unsigned int nr,
106 via_gpio_set(chip, nr, value);
111 * Set the input direction. I'm not sure this is right; we should
112 * be able to do input without disabling output.
114 static int via_gpio_dir_input(struct gpio_chip *chip, unsigned int nr)
116 struct viafb_gpio_cfg *cfg = gpiochip_get_data(chip);
117 struct viafb_gpio *gpio;
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);
128 static int via_gpio_get(struct gpio_chip *chip, unsigned int nr)
130 struct viafb_gpio_cfg *cfg = gpiochip_get_data(chip);
132 struct viafb_gpio *gpio;
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));
143 static struct viafb_gpio_cfg viafb_gpio_config = {
145 .label = "VIAFB onboard GPIO",
146 .owner = THIS_MODULE,
147 .direction_output = via_gpio_dir_out,
149 .direction_input = via_gpio_dir_input,
158 * Manage the software enable bit.
160 static void viafb_gpio_enable(struct viafb_gpio *gpio)
162 via_write_reg_mask(VIASR, gpio->vg_port_index, 0x02, 0x02);
165 static void viafb_gpio_disable(struct viafb_gpio *gpio)
167 via_write_reg_mask(VIASR, gpio->vg_port_index, 0, 0x02);
172 static int viafb_gpio_suspend(void *private)
177 static int viafb_gpio_resume(void *private)
181 for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i += 2)
182 viafb_gpio_enable(viafb_gpio_config.active_gpios[i]);
186 static struct viafb_pm_hooks viafb_gpio_pm_hooks = {
187 .suspend = viafb_gpio_suspend,
188 .resume = viafb_gpio_resume
190 #endif /* CONFIG_PM */
193 * Look up a specific gpio and return the number it was assigned.
195 int viafb_gpio_lookup(const char *name)
199 for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i++)
200 if (!strcmp(name, viafb_gpio_config.active_gpios[i]->vg_name))
201 return viafb_gpio_config.gpio_chip.base + i;
204 EXPORT_SYMBOL_GPL(viafb_gpio_lookup);
207 * Platform device stuff.
209 static int viafb_gpio_probe(struct platform_device *platdev)
211 struct viafb_dev *vdev = platdev->dev.platform_data;
212 struct via_port_cfg *port_cfg = vdev->port_cfg;
213 int i, ngpio = 0, ret;
214 struct viafb_gpio *gpio;
218 * Set up entries for all GPIOs which have been configured to
219 * operate as such (as opposed to as i2c ports).
221 for (i = 0; i < VIAFB_NUM_PORTS; i++) {
222 if (port_cfg[i].mode != VIA_MODE_GPIO)
224 for (gpio = viafb_all_gpios;
225 gpio < viafb_all_gpios + VIAFB_NUM_GPIOS; gpio++)
226 if (gpio->vg_port_index == port_cfg[i].ioport_index) {
227 viafb_gpio_config.active_gpios[ngpio] = gpio;
228 viafb_gpio_config.gpio_names[ngpio] =
233 viafb_gpio_config.gpio_chip.ngpio = ngpio;
234 viafb_gpio_config.gpio_chip.names = viafb_gpio_config.gpio_names;
235 viafb_gpio_config.vdev = vdev;
237 printk(KERN_INFO "viafb: no GPIOs configured\n");
241 * Enable the ports. They come in pairs, with a single
242 * enable bit for both.
244 spin_lock_irqsave(&viafb_gpio_config.vdev->reg_lock, flags);
245 for (i = 0; i < ngpio; i += 2)
246 viafb_gpio_enable(viafb_gpio_config.active_gpios[i]);
247 spin_unlock_irqrestore(&viafb_gpio_config.vdev->reg_lock, flags);
251 viafb_gpio_config.gpio_chip.base = -1; /* Dynamic */
252 ret = gpiochip_add_data(&viafb_gpio_config.gpio_chip,
255 printk(KERN_ERR "viafb: failed to add gpios (%d)\n", ret);
256 viafb_gpio_config.gpio_chip.ngpio = 0;
259 viafb_pm_register(&viafb_gpio_pm_hooks);
265 static int viafb_gpio_remove(struct platform_device *platdev)
271 viafb_pm_unregister(&viafb_gpio_pm_hooks);
277 if (viafb_gpio_config.gpio_chip.ngpio > 0) {
278 gpiochip_remove(&viafb_gpio_config.gpio_chip);
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(viafb_gpio_config.active_gpios[i]);
286 viafb_gpio_config.gpio_chip.ngpio = 0;
287 spin_unlock_irqrestore(&viafb_gpio_config.vdev->reg_lock, flags);
291 static struct platform_driver via_gpio_driver = {
293 .name = "viafb-gpio",
295 .probe = viafb_gpio_probe,
296 .remove = viafb_gpio_remove,
299 int viafb_gpio_init(void)
301 return platform_driver_register(&via_gpio_driver);
304 void viafb_gpio_exit(void)
306 platform_driver_unregister(&via_gpio_driver);