1 files changed, 285 insertions, 0 deletions

diff --git a/drivers/video/via/via-gpio.c b/drivers/video/via/via-gpio.c
new file mode 100644
index 000000000000..595516aea691
--- /dev/null
+++ b/drivers/video/via/via-gpio.c
@@ -0,0 +1,285 @@
+/*
+ * Support for viafb GPIO ports.
+ *
+ * Copyright 2009 Jonathan Corbet <corbet@lwn.net>
+ * Distributable under version 2 of the GNU General Public License.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include <linux/via-core.h>
+#include <linux/via-gpio.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 = via_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);
+        via_write_reg(VIASR, gpio->vg_port_index, 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];
+        via_write_reg_mask(VIASR, gpio->vg_port_index, 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 = via_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)
+{
+        via_write_reg_mask(VIASR, gpio->vg_port_index, 0x02, 0x02);
+}
+
+static void viafb_gpio_disable(struct viafb_gpio *gpio)
+{
+        via_write_reg_mask(VIASR, gpio->vg_port_index, 0, 0x02);
+}
+
+/*
+ * 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);
+
+/*
+ * Platform device stuff.
+ */
+static __devinit int viafb_gpio_probe(struct platform_device *platdev)
+{
+        struct viafb_dev *vdev = platdev->dev.platform_data;
+        struct via_port_cfg *port_cfg = vdev->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;
+}
+
+
+static int viafb_gpio_remove(struct platform_device *platdev)
+{
+        unsigned long flags;
+        int ret = 0, i;
+
+        /*
+         * 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");
+                        return ret;
+                }
+        }
+        /*
+         * Disable the ports.
+         */
+        spin_lock_irqsave(&gpio_config.vdev->reg_lock, flags);
+        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;
+        spin_unlock_irqrestore(&gpio_config.vdev->reg_lock, flags);
+        return ret;
+}
+
+static struct platform_driver via_gpio_driver = {
+        .driver = {
+                .name = "viafb-gpio",
+        },
+        .probe = viafb_gpio_probe,
+        .remove = viafb_gpio_remove,
+};
+
+int viafb_gpio_init(void)
+{
+        return platform_driver_register(&via_gpio_driver);
+}
+
+void viafb_gpio_exit(void)
+{
+        platform_driver_unregister(&via_gpio_driver);
+}