gpio: Add basic support for TWL6040 GPOs

TWL6040 provides GPO lines to be used for controlling external devices.The number
of lines different between versions: twl6040 have 3 GPO while TWL6041 have 1.

Signed-off-by: Sergio Aguirre <saaguirre@ti.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 137 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-twl6040.c b/drivers/gpio/gpio-twl6040.c
new file mode 100644
index 000000000000..dd58e8b25043
--- /dev/null
+++ b/drivers/gpio/gpio-twl6040.c
@@ -0,0 +1,137 @@
+/*
+ * Access to GPOs on TWL6040 chip
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc.
+ *
+ * Authors:
+ *      Sergio Aguirre <saaguirre@ti.com>
+ *      Peter Ujfalusi <peter.ujfalusi@ti.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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kthread.h>
+#include <linux/irq.h>
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+
+#include <linux/mfd/twl6040.h>
+
+static struct gpio_chip twl6040gpo_chip;
+
+static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
+{
+        struct twl6040 *twl6040 = dev_get_drvdata(chip->dev->parent);
+        int ret = 0;
+
+        ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
+        if (ret < 0)
+                return ret;
+
+        return (ret >> offset) & 1;
+}
+
+static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
+                                    int value)
+{
+        /* This only drives GPOs, and can't change direction */
+        return 0;
+}
+
+static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+        struct twl6040 *twl6040 = dev_get_drvdata(chip->dev->parent);
+        int ret;
+        u8 gpoctl;
+
+        ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
+        if (ret < 0)
+                return;
+
+        if (value)
+                gpoctl = ret | (1 << offset);
+        else
+                gpoctl = ret & ~(1 << offset);
+
+        twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
+}
+
+static struct gpio_chip twl6040gpo_chip = {
+        .label                  = "twl6040",
+        .owner                  = THIS_MODULE,
+        .get                    = twl6040gpo_get,
+        .direction_output       = twl6040gpo_direction_out,
+        .set                    = twl6040gpo_set,
+        .can_sleep              = 1,
+};
+
+/*----------------------------------------------------------------------*/
+
+static int __devinit gpo_twl6040_probe(struct platform_device *pdev)
+{
+        struct twl6040_gpo_data *pdata = pdev->dev.platform_data;
+        struct device *twl6040_core_dev = pdev->dev.parent;
+        struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
+        int ret;
+
+        if (pdata)
+                twl6040gpo_chip.base = pdata->gpio_base;
+        else
+                twl6040gpo_chip.base = -1;
+
+        if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
+                twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
+        else
+                twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
+
+        twl6040gpo_chip.dev = &pdev->dev;
+#ifdef CONFIG_OF_GPIO
+        twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
+#endif
+
+        ret = gpiochip_add(&twl6040gpo_chip);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
+                twl6040gpo_chip.ngpio = 0;
+        }
+
+        return ret;
+}
+
+static int __devexit gpo_twl6040_remove(struct platform_device *pdev)
+{
+        return gpiochip_remove(&twl6040gpo_chip);
+}
+
+/* Note:  this hardware lives inside an I2C-based multi-function device. */
+MODULE_ALIAS("platform:twl6040-gpo");
+
+static struct platform_driver gpo_twl6040_driver = {
+        .driver = {
+                .name   = "twl6040-gpo",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = gpo_twl6040_probe,
+        .remove         = gpo_twl6040_remove,
+};
+
+module_platform_driver(gpo_twl6040_driver);
+
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("GPO interface for TWL6040");
+MODULE_LICENSE("GPL");