gpiolib: Add WM8994 GPIO support

The WM8994 has 11 GPIO lines.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 212 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index acac9f60db1d..f42cb317a779 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -192,6 +192,13 @@ config GPIO_WM8350
           Say yes here to access the GPIO signals of WM8350 power management
           chips from Wolfson Microelectronics.
 
+config GPIO_WM8994
+        tristate "WM8994 GPIOs"
+        depends on MFD_WM8994
+        help
+          Say yes here to access the GPIO signals of WM8994 audio hub
+          CODECs from Wolfson Microelectronics.
+
 config GPIO_ADP5520
         tristate "GPIO Support for ADP5520 PMIC"
         depends on PMIC_ADP5520
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 90b0880923de..594bb70f65af 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -26,3 +26,4 @@ obj-$(CONFIG_GPIO_IT8761E)	+= it8761e_gpio.o
 obj-$(CONFIG_GPIO_VR41XX)       += vr41xx_giu.o
 obj-$(CONFIG_GPIO_WM831X)       += wm831x-gpio.o
 obj-$(CONFIG_GPIO_WM8350)       += wm8350-gpiolib.o
+obj-$(CONFIG_GPIO_WM8994)       += wm8994-gpio.o
diff --git a/drivers/gpio/wm8994-gpio.c b/drivers/gpio/wm8994-gpio.c
new file mode 100644
index 000000000000..de28b4a470ea
--- /dev/null
+++ b/drivers/gpio/wm8994-gpio.c
@@ -0,0 +1,204 @@
+/*
+ * wm8994-gpio.c  --  gpiolib support for Wolfson WM8994
+ *
+ * Copyright 2009 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/mfd/core.h>
+#include <linux/platform_device.h>
+#include <linux/seq_file.h>
+
+#include <linux/mfd/wm8994/core.h>
+#include <linux/mfd/wm8994/pdata.h>
+#include <linux/mfd/wm8994/gpio.h>
+#include <linux/mfd/wm8994/registers.h>
+
+struct wm8994_gpio {
+        struct wm8994 *wm8994;
+        struct gpio_chip gpio_chip;
+};
+
+static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip)
+{
+        return container_of(chip, struct wm8994_gpio, gpio_chip);
+}
+
+static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
+{
+        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
+        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
+
+        return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
+                               WM8994_GPN_DIR, WM8994_GPN_DIR);
+}
+
+static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
+        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
+        int ret;
+
+        ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset);
+        if (ret < 0)
+                return ret;
+
+        if (ret & WM8994_GPN_LVL)
+                return 1;
+        else
+                return 0;
+}
+
+static int wm8994_gpio_direction_out(struct gpio_chip *chip,
+                                     unsigned offset, int value)
+{
+        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
+        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
+
+        return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
+                               WM8994_GPN_DIR, 0);
+}
+
+static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
+        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
+
+        if (value)
+                value = WM8994_GPN_LVL;
+
+        wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value);
+}
+
+#ifdef CONFIG_DEBUG_FS
+static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
+{
+        struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
+        struct wm8994 *wm8994 = wm8994_gpio->wm8994;
+        int i;
+
+        for (i = 0; i < chip->ngpio; i++) {
+                int gpio = i + chip->base;
+                int reg;
+                const char *label;
+
+                /* We report the GPIO even if it's not requested since
+                 * we're also reporting things like alternate
+                 * functions which apply even when the GPIO is not in
+                 * use as a GPIO.
+                 */
+                label = gpiochip_is_requested(chip, i);
+                if (!label)
+                        label = "Unrequested";
+
+                seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
+
+                reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i);
+                if (reg < 0) {
+                        dev_err(wm8994->dev,
+                                "GPIO control %d read failed: %d\n",
+                                gpio, reg);
+                        seq_printf(s, "\n");
+                        continue;
+                }
+
+                /* No decode yet; note that GPIO2 is special */
+                seq_printf(s, "(%x)\n", reg);
+        }
+}
+#else
+#define wm8994_gpio_dbg_show NULL
+#endif
+
+static struct gpio_chip template_chip = {
+        .label                  = "wm8994",
+        .owner                  = THIS_MODULE,
+        .direction_input        = wm8994_gpio_direction_in,
+        .get                    = wm8994_gpio_get,
+        .direction_output       = wm8994_gpio_direction_out,
+        .set                    = wm8994_gpio_set,
+        .dbg_show               = wm8994_gpio_dbg_show,
+        .can_sleep              = 1,
+};
+
+static int __devinit wm8994_gpio_probe(struct platform_device *pdev)
+{
+        struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
+        struct wm8994_pdata *pdata = wm8994->dev->platform_data;
+        struct wm8994_gpio *wm8994_gpio;
+        int ret;
+
+        wm8994_gpio = kzalloc(sizeof(*wm8994_gpio), GFP_KERNEL);
+        if (wm8994_gpio == NULL)
+                return -ENOMEM;
+
+        wm8994_gpio->wm8994 = wm8994;
+        wm8994_gpio->gpio_chip = template_chip;
+        wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX;
+        wm8994_gpio->gpio_chip.dev = &pdev->dev;
+        if (pdata && pdata->gpio_base)
+                wm8994_gpio->gpio_chip.base = pdata->gpio_base;
+        else
+                wm8994_gpio->gpio_chip.base = -1;
+
+        ret = gpiochip_add(&wm8994_gpio->gpio_chip);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
+                        ret);
+                goto err;
+        }
+
+        platform_set_drvdata(pdev, wm8994_gpio);
+
+        return ret;
+
+err:
+        kfree(wm8994_gpio);
+        return ret;
+}
+
+static int __devexit wm8994_gpio_remove(struct platform_device *pdev)
+{
+        struct wm8994_gpio *wm8994_gpio = platform_get_drvdata(pdev);
+        int ret;
+
+        ret = gpiochip_remove(&wm8994_gpio->gpio_chip);
+        if (ret == 0)
+                kfree(wm8994_gpio);
+
+        return ret;
+}
+
+static struct platform_driver wm8994_gpio_driver = {
+        .driver.name    = "wm8994-gpio",
+        .driver.owner   = THIS_MODULE,
+        .probe          = wm8994_gpio_probe,
+        .remove         = __devexit_p(wm8994_gpio_remove),
+};
+
+static int __init wm8994_gpio_init(void)
+{
+        return platform_driver_register(&wm8994_gpio_driver);
+}
+subsys_initcall(wm8994_gpio_init);
+
+static void __exit wm8994_gpio_exit(void)
+{
+        platform_driver_unregister(&wm8994_gpio_driver);
+}
+module_exit(wm8994_gpio_exit);
+
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("GPIO interface for WM8994");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm8994-gpio");