On Wed, Nov 2, 2016 at 9:37 AM, Richard Vidal-Dorsch
[off-list ref] wrote:

Signed-off-by: Richard Vidal-Dorsch <redacted>

+#include <linux/device.h>
+#include <linux/gpio.h>

#include <linux/gpio/driver.h>
should be enough.

+#include <linux/init.h>
+#include <linux/mfd/imanager.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+
+#define EC_GPIOF_DIR_OUT       BIT(6)
+#define EC_GPIOF_DIR_IN                BIT(7)
+
+struct imanager_gpio_data {
+       struct imanager_device_data *imgr;
+       struct gpio_chip chip;
+};

Maybe some kerneldoc for this. Not necessary though since its sort of
self-explanatory.

+static int imanager_gpio_direction_in(struct gpio_chip *chip, uint offset)
+{
+       struct imanager_gpio_data *data = gpiochip_get_data(chip);
+       struct imanager_device_data *imgr = data->imgr;
+       struct imanager_device_attribute *attr = imgr->ec.gpio.attr[offset];
+
+       mutex_lock(&imgr->lock);
+       imanager_write8(&imgr->ec, EC_CMD_GPIO_DIR_WR, attr->did,
+                       EC_GPIOF_DIR_IN);
+       mutex_unlock(&imgr->lock);

It kind of looks like it would be smarter if the imanager_write8() was
taking and releasing the lock so you don't have to do it everywhere.

+static int imanager_gpio_get_direction(struct gpio_chip *chip, uint offset)
+{
+       struct imanager_gpio_data *data = gpiochip_get_data(chip);
+       struct imanager_device_data *imgr = data->imgr;
+       struct imanager_device_attribute *attr = imgr->ec.gpio.attr[offset];
+       int ret;
+
+       mutex_lock(&imgr->lock);
+       ret = imanager_read8(&imgr->ec, EC_CMD_GPIO_DIR_RD, attr->did);
+       mutex_unlock(&imgr->lock);
+
+       return ret & EC_GPIOF_DIR_IN ? GPIOF_DIR_IN : GPIOF_DIR_OUT;

Don't use GPIOF* flags, those are for consumers. Just return 0/1.

+static int imanager_gpio_get(struct gpio_chip *chip, uint offset)
+{
+       struct imanager_gpio_data *data = gpiochip_get_data(chip);
+       struct imanager_device_data *imgr = data->imgr;
+       struct imanager_device_attribute *attr = imgr->ec.gpio.attr[offset];
+       int ret;
+
+       mutex_lock(&imgr->lock);
+       ret = imanager_read8(&imgr->ec, EC_CMD_HWP_RD, attr->did);
+       mutex_unlock(&imgr->lock);
+
+       return ret;
+}

Can the read function return an error code? In that case it should be checked
everywhere.

Also be sure to clamp ret like this:

return !!ret;

Apart from this it looks good.

Yours,
Linus Walleij