gpio: Add ROHM BD9571MWV-M PMIC GPIO driver

Add driver for the GPIO block in the ROHM BD9571MWV-W MFD PMIC.
This block is pretty trivial and supports setting GPIO direction
as Input/Output and in case of Output, supports setting value.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: linux-gpio@vger.kernel.org
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

3 files changed, 156 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index c0629e6639fa..5662b0580777 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -844,6 +844,17 @@ config GPIO_ARIZONA
         help
           Support for GPIOs on Wolfson Arizona class devices.
 
+config GPIO_BD9571MWV
+        tristate "ROHM BD9571 GPIO support"
+        depends on MFD_BD9571MWV
+        help
+          Support for GPIOs on ROHM BD9571 PMIC. There are two GPIOs
+          available on the ROHM PMIC in total, both of which can also
+          generate interrupts.
+
+          This driver can also be built as a module. If so, the module
+          will be called gpio-bd9571mwv.
+
 config GPIO_CRYSTAL_COVE
         tristate "GPIO support for Crystal Cove PMIC"
         depends on (X86 || COMPILE_TEST) && INTEL_SOC_PMIC
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 095598e856ca..68b96277d9fa 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_GPIO_ATH79)	+= gpio-ath79.o
 obj-$(CONFIG_GPIO_ASPEED)       += gpio-aspeed.o
 obj-$(CONFIG_GPIO_AXP209)       += gpio-axp209.o
 obj-$(CONFIG_GPIO_BCM_KONA)     += gpio-bcm-kona.o
+obj-$(CONFIG_GPIO_BD9571MWV)    += gpio-bd9571mwv.o
 obj-$(CONFIG_GPIO_BRCMSTB)      += gpio-brcmstb.o
 obj-$(CONFIG_GPIO_BT8XX)        += gpio-bt8xx.o
 obj-$(CONFIG_GPIO_CLPS711X)     += gpio-clps711x.o
diff --git a/drivers/gpio/gpio-bd9571mwv.c b/drivers/gpio/gpio-bd9571mwv.c
new file mode 100644
index 000000000000..5224a946e8ab
--- /dev/null
+++ b/drivers/gpio/gpio-bd9571mwv.c
@@ -0,0 +1,144 @@
+/*
+ * ROHM BD9571MWV-M GPIO driver
+ *
+ * Copyright (C) 2017 Marek Vasut <marek.vasut+renesas@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether expressed or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License version 2 for more details.
+ *
+ * Based on the TPS65086 driver
+ *
+ * NOTE: Interrupts are not supported yet.
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <linux/mfd/bd9571mwv.h>
+
+struct bd9571mwv_gpio {
+        struct gpio_chip chip;
+        struct bd9571mwv *bd;
+};
+
+static int bd9571mwv_gpio_get_direction(struct gpio_chip *chip,
+                                       unsigned int offset)
+{
+        struct bd9571mwv_gpio *gpio = gpiochip_get_data(chip);
+        int ret, val;
+
+        ret = regmap_read(gpio->bd->regmap, BD9571MWV_GPIO_DIR, &val);
+        if (ret < 0)
+                return ret;
+
+        return val & BIT(offset);
+}
+
+static int bd9571mwv_gpio_direction_input(struct gpio_chip *chip,
+                                         unsigned int offset)
+{
+        struct bd9571mwv_gpio *gpio = gpiochip_get_data(chip);
+
+        regmap_update_bits(gpio->bd->regmap, BD9571MWV_GPIO_DIR,
+                           BIT(offset), 0);
+
+        return 0;
+}
+
+static int bd9571mwv_gpio_direction_output(struct gpio_chip *chip,
+                                          unsigned int offset, int value)
+{
+        struct bd9571mwv_gpio *gpio = gpiochip_get_data(chip);
+
+        /* Set the initial value */
+        regmap_update_bits(gpio->bd->regmap, BD9571MWV_GPIO_OUT,
+                           BIT(offset), value ? BIT(offset) : 0);
+        regmap_update_bits(gpio->bd->regmap, BD9571MWV_GPIO_DIR,
+                           BIT(offset), BIT(offset));
+
+        return 0;
+}
+
+static int bd9571mwv_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+        struct bd9571mwv_gpio *gpio = gpiochip_get_data(chip);
+        int ret, val;
+
+        ret = regmap_read(gpio->bd->regmap, BD9571MWV_GPIO_IN, &val);
+        if (ret < 0)
+                return ret;
+
+        return val & BIT(offset);
+}
+
+static void bd9571mwv_gpio_set(struct gpio_chip *chip, unsigned int offset,
+                              int value)
+{
+        struct bd9571mwv_gpio *gpio = gpiochip_get_data(chip);
+
+        regmap_update_bits(gpio->bd->regmap, BD9571MWV_GPIO_OUT,
+                           BIT(offset), value ? BIT(offset) : 0);
+}
+
+static const struct gpio_chip template_chip = {
+        .label                  = "bd9571mwv-gpio",
+        .owner                  = THIS_MODULE,
+        .get_direction          = bd9571mwv_gpio_get_direction,
+        .direction_input        = bd9571mwv_gpio_direction_input,
+        .direction_output       = bd9571mwv_gpio_direction_output,
+        .get                    = bd9571mwv_gpio_get,
+        .set                    = bd9571mwv_gpio_set,
+        .base                   = -1,
+        .ngpio                  = 2,
+        .can_sleep              = true,
+};
+
+static int bd9571mwv_gpio_probe(struct platform_device *pdev)
+{
+        struct bd9571mwv_gpio *gpio;
+        int ret;
+
+        gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
+        if (!gpio)
+                return -ENOMEM;
+
+        platform_set_drvdata(pdev, gpio);
+
+        gpio->bd = dev_get_drvdata(pdev->dev.parent);
+        gpio->chip = template_chip;
+        gpio->chip.parent = gpio->bd->dev;
+
+        ret = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
+                return ret;
+        }
+
+        return 0;
+}
+
+static const struct platform_device_id bd9571mwv_gpio_id_table[] = {
+        { "bd9571mwv-gpio", },
+        { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, bd9571mwv_gpio_id_table);
+
+static struct platform_driver bd9571mwv_gpio_driver = {
+        .driver = {
+                .name = "bd9571mwv-gpio",
+        },
+        .probe = bd9571mwv_gpio_probe,
+        .id_table = bd9571mwv_gpio_id_table,
+};
+module_platform_driver(bd9571mwv_gpio_driver);
+
+MODULE_AUTHOR("Marek Vasut <marek.vasut+renesas@gmail.com>");
+MODULE_DESCRIPTION("BD9571MWV GPIO driver");
+MODULE_LICENSE("GPL v2");