/* * Support for viafb GPIO ports. * * Copyright 2009 Jonathan Corbet * Distributable under version 2 of the GNU General Public License. */ #include #include #include "via-core.h" #include "via-gpio.h" #include "global.h" /* * The ports we know about. Note that the port-25 gpios are not * mentioned in the datasheet. */ struct viafb_gpio { char *vg_name; /* Data sheet name */ u16 vg_io_port; u8 vg_port_index; int vg_mask_shift; }; static struct viafb_gpio viafb_all_gpios[] = { { .vg_name = "VGPIO0", /* Guess - not in datasheet */ .vg_io_port = VIASR, .vg_port_index = 0x25, .vg_mask_shift = 1 }, { .vg_name = "VGPIO1", .vg_io_port = VIASR, .vg_port_index = 0x25, .vg_mask_shift = 0 }, { .vg_name = "VGPIO2", /* aka DISPCLKI0 */ .vg_io_port = VIASR, .vg_port_index = 0x2c, .vg_mask_shift = 1 }, { .vg_name = "VGPIO3", /* aka DISPCLKO0 */ .vg_io_port = VIASR, .vg_port_index = 0x2c, .vg_mask_shift = 0 }, { .vg_name = "VGPIO4", /* DISPCLKI1 */ .vg_io_port = VIASR, .vg_port_index = 0x3d, .vg_mask_shift = 1 }, { .vg_name = "VGPIO5", /* DISPCLKO1 */ .vg_io_port = VIASR, .vg_port_index = 0x3d, .vg_mask_shift = 0 }, }; #define VIAFB_NUM_GPIOS ARRAY_SIZE(viafb_all_gpios) /* * This structure controls the active GPIOs, which may be a subset * of those which are known. */ struct viafb_gpio_cfg { struct gpio_chip gpio_chip; struct viafb_dev *vdev; struct viafb_gpio *active_gpios[VIAFB_NUM_GPIOS]; char *gpio_names[VIAFB_NUM_GPIOS]; }; /* * GPIO access functions */ static void via_gpio_set(struct gpio_chip *chip, unsigned int nr, int value) { struct viafb_gpio_cfg *cfg = container_of(chip, struct viafb_gpio_cfg, gpio_chip); u8 reg; struct viafb_gpio *gpio; unsigned long flags; spin_lock_irqsave(&cfg->vdev->reg_lock, flags); gpio = cfg->active_gpios[nr]; reg = viafb_read_reg(VIASR, gpio->vg_port_index); reg |= 0x40 << gpio->vg_mask_shift; /* output enable */ if (value) reg |= 0x10 << gpio->vg_mask_shift; else reg &= ~(0x10 << gpio->vg_mask_shift); viafb_write_reg(gpio->vg_port_index, VIASR, reg); spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags); } static int via_gpio_dir_out(struct gpio_chip *chip, unsigned int nr, int value) { via_gpio_set(chip, nr, value); return 0; } /* * Set the input direction. I'm not sure this is right; we should * be able to do input without disabling output. */ static int via_gpio_dir_input(struct gpio_chip *chip, unsigned int nr) { struct viafb_gpio_cfg *cfg = container_of(chip, struct viafb_gpio_cfg, gpio_chip); struct viafb_gpio *gpio; unsigned long flags; spin_lock_irqsave(&cfg->vdev->reg_lock, flags); gpio = cfg->active_gpios[nr]; viafb_write_reg_mask(gpio->vg_port_index, VIASR, 0, 0x40 << gpio->vg_mask_shift); spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags); return 0; } static int via_gpio_get(struct gpio_chip *chip, unsigned int nr) { struct viafb_gpio_cfg *cfg = container_of(chip, struct viafb_gpio_cfg, gpio_chip); u8 reg; struct viafb_gpio *gpio; unsigned long flags; spin_lock_irqsave(&cfg->vdev->reg_lock, flags); gpio = cfg->active_gpios[nr]; reg = viafb_read_reg(VIASR, gpio->vg_port_index); spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags); return reg & (0x04 << gpio->vg_mask_shift); } static struct viafb_gpio_cfg gpio_config = { .gpio_chip = { .label = "VIAFB onboard GPIO", .owner = THIS_MODULE, .direction_output = via_gpio_dir_out, .set = via_gpio_set, .direction_input = via_gpio_dir_input, .get = via_gpio_get, .base = -1, .ngpio = 0, .can_sleep = 0 } }; /* * Manage the software enable bit. */ static void viafb_gpio_enable(struct viafb_gpio *gpio) { viafb_write_reg_mask(gpio->vg_port_index, VIASR, 0x02, 0x02); } static void viafb_gpio_disable(struct viafb_gpio *gpio) { viafb_write_reg_mask(gpio->vg_port_index, VIASR, 0, 0x02); } int viafb_create_gpios(struct viafb_dev *vdev, const struct via_port_cfg *port_cfg) { int i, ngpio = 0, ret; struct viafb_gpio *gpio; unsigned long flags; /* * Set up entries for all GPIOs which have been configured to * operate as such (as opposed to as i2c ports). */ for (i = 0; i < VIAFB_NUM_PORTS; i++) { if (port_cfg[i].mode != VIA_MODE_GPIO) continue; for (gpio = viafb_all_gpios; gpio < viafb_all_gpios + VIAFB_NUM_GPIOS; gpio++) if (gpio->vg_port_index == port_cfg[i].ioport_index) { gpio_config.active_gpios[ngpio] = gpio; gpio_config.gpio_names[ngpio] = gpio->vg_name; ngpio++; } } gpio_config.gpio_chip.ngpio = ngpio; gpio_config.gpio_chip.names = gpio_config.gpio_names; gpio_config.vdev = vdev; if (ngpio == 0) { printk(KERN_INFO "viafb: no GPIOs configured\n"); return 0; } /* * Enable the ports. They come in pairs, with a single * enable bit for both. */ spin_lock_irqsave(&gpio_config.vdev->reg_lock, flags); for (i = 0; i < ngpio; i += 2) viafb_gpio_enable(gpio_config.active_gpios[i]); spin_unlock_irqrestore(&gpio_config.vdev->reg_lock, flags); /* * Get registered. */ gpio_config.gpio_chip.base = -1; /* Dynamic */ ret = gpiochip_add(&gpio_config.gpio_chip); if (ret) { printk(KERN_ERR "viafb: failed to add gpios (%d)\n", ret); gpio_config.gpio_chip.ngpio = 0; } return ret; /* Port enable ? */ } int viafb_destroy_gpios(void) { unsigned long flags; int ret = 0, i; spin_lock_irqsave(&gpio_config.vdev->reg_lock, flags); /* * Get unregistered. */ if (gpio_config.gpio_chip.ngpio > 0) { ret = gpiochip_remove(&gpio_config.gpio_chip); if (ret) { /* Somebody still using it? */ printk(KERN_ERR "Viafb: GPIO remove failed\n"); goto out; } } /* * Disable the ports. */ for (i = 0; i < gpio_config.gpio_chip.ngpio; i += 2) viafb_gpio_disable(gpio_config.active_gpios[i]); gpio_config.gpio_chip.ngpio = 0; out: spin_unlock_irqrestore(&gpio_config.vdev->reg_lock, flags); return ret; } /* * Look up a specific gpio and return the number it was assigned. */ int viafb_gpio_lookup(const char *name) { int i; for (i = 0; i < gpio_config.gpio_chip.ngpio; i++) if (!strcmp(name, gpio_config.active_gpios[i]->vg_name)) return gpio_config.gpio_chip.base + i; return -1; } EXPORT_SYMBOL_GPL(viafb_gpio_lookup);