gpio: Add viperboard gpio driver

This adds the mfd cell to use the gpio a and gpio b part
of the Nano River Technologies viperboard.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 531 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d055cee36942..c3bbd08bcdc3 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -649,4 +649,17 @@ config GPIO_MSIC
           Enable support for GPIO on intel MSIC controllers found in
           intel MID devices
 
+comment "USB GPIO expanders:"
+
+config GPIO_VIPERBOARD
+        tristate "Viperboard GPIO a & b support"
+        depends on MFD_VIPERBOARD && USB
+        help
+          Say yes here to access the GPIO signals of Nano River
+          Technologies Viperboard. There are two GPIO chips on the
+          board: gpioa and gpiob.
+          See viperboard API specification and Nano
+          River Tech's viperboard.h for detailed meaning
+          of the module parameters.
+
 endif
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 9aeed6707326..16a1385226e9 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -71,6 +71,7 @@ obj-$(CONFIG_GPIO_TPS65912)	+= gpio-tps65912.o
 obj-$(CONFIG_GPIO_TWL4030)      += gpio-twl4030.o
 obj-$(CONFIG_GPIO_TWL6040)      += gpio-twl6040.o
 obj-$(CONFIG_GPIO_UCB1400)      += gpio-ucb1400.o
+obj-$(CONFIG_GPIO_VIPERBOARD)   += gpio-viperboard.o
 obj-$(CONFIG_GPIO_VR41XX)       += gpio-vr41xx.o
 obj-$(CONFIG_GPIO_VT8500)       += gpio-vt8500.o
 obj-$(CONFIG_GPIO_VX855)        += gpio-vx855.o
diff --git a/drivers/gpio/gpio-viperboard.c b/drivers/gpio/gpio-viperboard.c
new file mode 100644
index 000000000000..13772996cf24
--- /dev/null
+++ b/drivers/gpio/gpio-viperboard.c
@@ -0,0 +1,517 @@
+/*
+ *  Nano River Technologies viperboard GPIO lib driver
+ *
+ *  (C) 2012 by Lemonage GmbH
+ *  Author: Lars Poeschel <poeschel@lemonage.de>
+ *  All rights reserved.
+ *
+ *  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/errno.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+
+#include <linux/usb.h>
+#include <linux/gpio.h>
+
+#include <linux/mfd/viperboard.h>
+
+#define VPRBRD_GPIOA_CLK_1MHZ           0
+#define VPRBRD_GPIOA_CLK_100KHZ         1
+#define VPRBRD_GPIOA_CLK_10KHZ          2
+#define VPRBRD_GPIOA_CLK_1KHZ           3
+#define VPRBRD_GPIOA_CLK_100HZ          4
+#define VPRBRD_GPIOA_CLK_10HZ           5
+
+#define VPRBRD_GPIOA_FREQ_DEFAULT       1000
+
+#define VPRBRD_GPIOA_CMD_CONT           0x00
+#define VPRBRD_GPIOA_CMD_PULSE          0x01
+#define VPRBRD_GPIOA_CMD_PWM            0x02
+#define VPRBRD_GPIOA_CMD_SETOUT         0x03
+#define VPRBRD_GPIOA_CMD_SETIN          0x04
+#define VPRBRD_GPIOA_CMD_SETINT         0x05
+#define VPRBRD_GPIOA_CMD_GETIN          0x06
+
+#define VPRBRD_GPIOB_CMD_SETDIR         0x00
+#define VPRBRD_GPIOB_CMD_SETVAL         0x01
+
+struct vprbrd_gpioa_msg {
+        u8 cmd;
+        u8 clk;
+        u8 offset;
+        u8 t1;
+        u8 t2;
+        u8 invert;
+        u8 pwmlevel;
+        u8 outval;
+        u8 risefall;
+        u8 answer;
+        u8 __fill;
+} __packed;
+
+struct vprbrd_gpiob_msg {
+        u8 cmd;
+        u16 val;
+        u16 mask;
+} __packed;
+
+struct vprbrd_gpio {
+        struct gpio_chip gpioa; /* gpio a related things */
+        u32 gpioa_out;
+        u32 gpioa_val;
+        struct gpio_chip gpiob; /* gpio b related things */
+        u32 gpiob_out;
+        u32 gpiob_val;
+        struct vprbrd *vb;
+};
+
+/* gpioa sampling clock module parameter */
+static unsigned char gpioa_clk;
+static unsigned int gpioa_freq = VPRBRD_GPIOA_FREQ_DEFAULT;
+module_param(gpioa_freq, uint, 0);
+MODULE_PARM_DESC(gpioa_freq,
+        "gpio-a sampling freq in Hz (default is 1000Hz) valid values: 10, 100, 1000, 10000, 100000, 1000000");
+
+/* ----- begin of gipo a chip -------------------------------------------- */
+
+static int vprbrd_gpioa_get(struct gpio_chip *chip,
+                unsigned offset)
+{
+        int ret, answer, error = 0;
+        struct vprbrd_gpio *gpio =
+                        container_of(chip, struct vprbrd_gpio, gpioa);
+        struct vprbrd *vb = gpio->vb;
+        struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
+
+        /* if io is set to output, just return the saved value */
+        if (gpio->gpioa_out & (1 << offset))
+                return gpio->gpioa_val & (1 << offset);
+
+        mutex_lock(&vb->lock);
+
+        gamsg->cmd = VPRBRD_GPIOA_CMD_GETIN;
+        gamsg->clk = 0x00;
+        gamsg->offset = offset;
+        gamsg->t1 = 0x00;
+        gamsg->t2 = 0x00;
+        gamsg->invert = 0x00;
+        gamsg->pwmlevel = 0x00;
+        gamsg->outval = 0x00;
+        gamsg->risefall = 0x00;
+        gamsg->answer = 0x00;
+        gamsg->__fill = 0x00;
+
+        ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
+                VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
+                0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
+                VPRBRD_USB_TIMEOUT_MS);
+        if (ret != sizeof(struct vprbrd_gpioa_msg))
+                error = -EREMOTEIO;
+
+        ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
+                VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_IN, 0x0000,
+                0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
+                VPRBRD_USB_TIMEOUT_MS);
+        answer = gamsg->answer & 0x01;
+
+        mutex_unlock(&vb->lock);
+
+        if (ret != sizeof(struct vprbrd_gpioa_msg))
+                error = -EREMOTEIO;
+
+        if (error)
+                return error;
+
+        return answer;
+}
+
+static void vprbrd_gpioa_set(struct gpio_chip *chip,
+                unsigned offset, int value)
+{
+        int ret;
+        struct vprbrd_gpio *gpio =
+                        container_of(chip, struct vprbrd_gpio, gpioa);
+        struct vprbrd *vb = gpio->vb;
+        struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
+
+        if (gpio->gpioa_out & (1 << offset)) {
+                if (value)
+                        gpio->gpioa_val |= (1 << offset);
+                else
+                        gpio->gpioa_val &= ~(1 << offset);
+
+                mutex_lock(&vb->lock);
+
+                gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
+                gamsg->clk = 0x00;
+                gamsg->offset = offset;
+                gamsg->t1 = 0x00;
+                gamsg->t2 = 0x00;
+                gamsg->invert = 0x00;
+                gamsg->pwmlevel = 0x00;
+                gamsg->outval = value;
+                gamsg->risefall = 0x00;
+                gamsg->answer = 0x00;
+                gamsg->__fill = 0x00;
+
+                ret = usb_control_msg(vb->usb_dev,
+                        usb_sndctrlpipe(vb->usb_dev, 0),
+                        VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT,
+                        0x0000, 0x0000, gamsg,
+                        sizeof(struct vprbrd_gpioa_msg), VPRBRD_USB_TIMEOUT_MS);
+
+                mutex_unlock(&vb->lock);
+
+                if (ret != sizeof(struct vprbrd_gpioa_msg))
+                        dev_err(chip->dev, "usb error setting pin value\n");
+        }
+}
+
+static int vprbrd_gpioa_direction_input(struct gpio_chip *chip,
+                        unsigned offset)
+{
+        int ret;
+        struct vprbrd_gpio *gpio =
+                        container_of(chip, struct vprbrd_gpio, gpioa);
+        struct vprbrd *vb = gpio->vb;
+        struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
+
+        gpio->gpioa_out &= ~(1 << offset);
+
+        mutex_lock(&vb->lock);
+
+        gamsg->cmd = VPRBRD_GPIOA_CMD_SETIN;
+        gamsg->clk = gpioa_clk;
+        gamsg->offset = offset;
+        gamsg->t1 = 0x00;
+        gamsg->t2 = 0x00;
+        gamsg->invert = 0x00;
+        gamsg->pwmlevel = 0x00;
+        gamsg->outval = 0x00;
+        gamsg->risefall = 0x00;
+        gamsg->answer = 0x00;
+        gamsg->__fill = 0x00;
+
+        ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
+                VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
+                0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
+                VPRBRD_USB_TIMEOUT_MS);
+
+        mutex_unlock(&vb->lock);
+
+        if (ret != sizeof(struct vprbrd_gpioa_msg))
+                return -EREMOTEIO;
+
+        return 0;
+}
+
+static int vprbrd_gpioa_direction_output(struct gpio_chip *chip,
+                        unsigned offset, int value)
+{
+        int ret;
+        struct vprbrd_gpio *gpio =
+                        container_of(chip, struct vprbrd_gpio, gpioa);
+        struct vprbrd *vb = gpio->vb;
+        struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
+
+        gpio->gpioa_out |= (1 << offset);
+        if (value)
+                gpio->gpioa_val |= (1 << offset);
+        else
+                gpio->gpioa_val &= ~(1 << offset);
+
+        mutex_lock(&vb->lock);
+
+        gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
+        gamsg->clk = 0x00;
+        gamsg->offset = offset;
+        gamsg->t1 = 0x00;
+        gamsg->t2 = 0x00;
+        gamsg->invert = 0x00;
+        gamsg->pwmlevel = 0x00;
+        gamsg->outval = value;
+        gamsg->risefall = 0x00;
+        gamsg->answer = 0x00;
+        gamsg->__fill = 0x00;
+
+        ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
+                VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
+                0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
+                VPRBRD_USB_TIMEOUT_MS);
+
+        mutex_unlock(&vb->lock);
+
+        if (ret != sizeof(struct vprbrd_gpioa_msg))
+                return -EREMOTEIO;
+
+        return 0;
+}
+
+/* ----- end of gpio a chip ---------------------------------------------- */
+
+/* ----- begin of gipo b chip -------------------------------------------- */
+
+static int vprbrd_gpiob_setdir(struct vprbrd *vb, unsigned offset,
+        unsigned dir)
+{
+        struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
+        int ret;
+
+        gbmsg->cmd = VPRBRD_GPIOB_CMD_SETDIR;
+        gbmsg->val = cpu_to_be16(dir << offset);
+        gbmsg->mask = cpu_to_be16(0x0001 << offset);
+
+        ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
+                VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT, 0x0000,
+                0x0000, gbmsg, sizeof(struct vprbrd_gpiob_msg),
+                VPRBRD_USB_TIMEOUT_MS);
+
+        if (ret != sizeof(struct vprbrd_gpiob_msg))
+                return -EREMOTEIO;
+
+        return 0;
+}
+
+static int vprbrd_gpiob_get(struct gpio_chip *chip,
+                unsigned offset)
+{
+        int ret;
+        u16 val;
+        struct vprbrd_gpio *gpio =
+                        container_of(chip, struct vprbrd_gpio, gpiob);
+        struct vprbrd *vb = gpio->vb;
+        struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
+
+        /* if io is set to output, just return the saved value */
+        if (gpio->gpiob_out & (1 << offset))
+                return gpio->gpiob_val & (1 << offset);
+
+        mutex_lock(&vb->lock);
+
+        ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
+                VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_IN, 0x0000,
+                0x0000, gbmsg,  sizeof(struct vprbrd_gpiob_msg),
+                VPRBRD_USB_TIMEOUT_MS);
+        val = gbmsg->val;
+
+        mutex_unlock(&vb->lock);
+
+        if (ret != sizeof(struct vprbrd_gpiob_msg))
+                return ret;
+
+        /* cache the read values */
+        gpio->gpiob_val = be16_to_cpu(val);
+
+        return (gpio->gpiob_val >> offset) & 0x1;
+}
+
+static void vprbrd_gpiob_set(struct gpio_chip *chip,
+                unsigned offset, int value)
+{
+        int ret;
+        struct vprbrd_gpio *gpio =
+                        container_of(chip, struct vprbrd_gpio, gpiob);
+        struct vprbrd *vb = gpio->vb;
+        struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
+
+        if (gpio->gpiob_out & (1 << offset)) {
+                if (value)
+                        gpio->gpiob_val |= (1 << offset);
+                else
+                        gpio->gpiob_val &= ~(1 << offset);
+
+                mutex_lock(&vb->lock);
+
+                gbmsg->cmd = VPRBRD_GPIOB_CMD_SETVAL;
+                gbmsg->val = cpu_to_be16(value << offset);
+                gbmsg->mask = cpu_to_be16(0x0001 << offset);
+
+                ret = usb_control_msg(vb->usb_dev,
+                        usb_sndctrlpipe(vb->usb_dev, 0),
+                        VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT,
+                        0x0000, 0x0000, gbmsg,
+                        sizeof(struct vprbrd_gpiob_msg), VPRBRD_USB_TIMEOUT_MS);
+
+                mutex_unlock(&vb->lock);
+
+                if (ret != sizeof(struct vprbrd_gpiob_msg))
+                        dev_err(chip->dev, "usb error setting pin value\n");
+        }
+}
+
+static int vprbrd_gpiob_direction_input(struct gpio_chip *chip,
+                        unsigned offset)
+{
+        int ret;
+        struct vprbrd_gpio *gpio =
+                        container_of(chip, struct vprbrd_gpio, gpiob);
+        struct vprbrd *vb = gpio->vb;
+
+        gpio->gpiob_out &= ~(1 << offset);
+
+        mutex_lock(&vb->lock);
+
+        ret = vprbrd_gpiob_setdir(vb, offset, 0);
+
+        mutex_unlock(&vb->lock);
+
+        if (ret)
+                dev_err(chip->dev, "usb error setting pin to input\n");
+
+        return ret;
+}
+
+static int vprbrd_gpiob_direction_output(struct gpio_chip *chip,
+                        unsigned offset, int value)
+{
+        int ret;
+        struct vprbrd_gpio *gpio =
+                        container_of(chip, struct vprbrd_gpio, gpiob);
+        struct vprbrd *vb = gpio->vb;
+
+        gpio->gpiob_out |= (1 << offset);
+        if (value)
+                gpio->gpiob_val |= (1 << offset);
+        else
+                gpio->gpiob_val &= ~(1 << offset);
+
+        mutex_lock(&vb->lock);
+
+        ret = vprbrd_gpiob_setdir(vb, offset, 1);
+        if (ret)
+                dev_err(chip->dev, "usb error setting pin to output\n");
+
+        mutex_unlock(&vb->lock);
+
+        vprbrd_gpiob_set(chip, offset, value);
+
+        return ret;
+}
+
+/* ----- end of gpio b chip ---------------------------------------------- */
+
+static int __devinit vprbrd_gpio_probe(struct platform_device *pdev)
+{
+        struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
+        struct vprbrd_gpio *vb_gpio;
+        int ret;
+
+        vb_gpio = devm_kzalloc(&pdev->dev, sizeof(*vb_gpio), GFP_KERNEL);
+        if (vb_gpio == NULL)
+                return -ENOMEM;
+
+        vb_gpio->vb = vb;
+        /* registering gpio a */
+        vb_gpio->gpioa.label = "viperboard gpio a";
+        vb_gpio->gpioa.dev = &pdev->dev;
+        vb_gpio->gpioa.owner = THIS_MODULE;
+        vb_gpio->gpioa.base = -1;
+        vb_gpio->gpioa.ngpio = 16;
+        vb_gpio->gpioa.can_sleep = 1;
+        vb_gpio->gpioa.set = vprbrd_gpioa_set;
+        vb_gpio->gpioa.get = vprbrd_gpioa_get;
+        vb_gpio->gpioa.direction_input = vprbrd_gpioa_direction_input;
+        vb_gpio->gpioa.direction_output = vprbrd_gpioa_direction_output;
+        ret = gpiochip_add(&vb_gpio->gpioa);
+        if (ret < 0) {
+                dev_err(vb_gpio->gpioa.dev, "could not add gpio a");
+                goto err_gpioa;
+        }
+
+        /* registering gpio b */
+        vb_gpio->gpiob.label = "viperboard gpio b";
+        vb_gpio->gpiob.dev = &pdev->dev;
+        vb_gpio->gpiob.owner = THIS_MODULE;
+        vb_gpio->gpiob.base = -1;
+        vb_gpio->gpiob.ngpio = 16;
+        vb_gpio->gpiob.can_sleep = 1;
+        vb_gpio->gpiob.set = vprbrd_gpiob_set;
+        vb_gpio->gpiob.get = vprbrd_gpiob_get;
+        vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
+        vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;
+        ret = gpiochip_add(&vb_gpio->gpiob);
+        if (ret < 0) {
+                dev_err(vb_gpio->gpiob.dev, "could not add gpio b");
+                goto err_gpiob;
+        }
+
+        platform_set_drvdata(pdev, vb_gpio);
+
+        return ret;
+
+err_gpiob:
+        ret = gpiochip_remove(&vb_gpio->gpioa);
+
+err_gpioa:
+        return ret;
+}
+
+static int __devexit vprbrd_gpio_remove(struct platform_device *pdev)
+{
+        struct vprbrd_gpio *vb_gpio = platform_get_drvdata(pdev);
+        int ret;
+
+        ret = gpiochip_remove(&vb_gpio->gpiob);
+        if (ret == 0)
+                ret = gpiochip_remove(&vb_gpio->gpioa);
+
+        return ret;
+}
+
+static struct platform_driver vprbrd_gpio_driver = {
+        .driver.name    = "viperboard-gpio",
+        .driver.owner   = THIS_MODULE,
+        .probe          = vprbrd_gpio_probe,
+        .remove         = __devexit_p(vprbrd_gpio_remove),
+};
+
+static int __init vprbrd_gpio_init(void)
+{
+        switch (gpioa_freq) {
+        case 1000000:
+                gpioa_clk = VPRBRD_GPIOA_CLK_1MHZ;
+                break;
+        case 100000:
+                gpioa_clk = VPRBRD_GPIOA_CLK_100KHZ;
+                break;
+        case 10000:
+                gpioa_clk = VPRBRD_GPIOA_CLK_10KHZ;
+                break;
+        case 1000:
+                gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
+                break;
+        case 100:
+                gpioa_clk = VPRBRD_GPIOA_CLK_100HZ;
+                break;
+        case 10:
+                gpioa_clk = VPRBRD_GPIOA_CLK_10HZ;
+                break;
+        default:
+                pr_warn("invalid gpioa_freq (%d)\n", gpioa_freq);
+                gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
+        }
+
+        return platform_driver_register(&vprbrd_gpio_driver);
+}
+subsys_initcall(vprbrd_gpio_init);
+
+static void __exit vprbrd_gpio_exit(void)
+{
+        platform_driver_unregister(&vprbrd_gpio_driver);
+}
+module_exit(vprbrd_gpio_exit);
+
+MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
+MODULE_DESCRIPTION("GPIO driver for Nano River Techs Viperboard");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:viperboard-gpio");