gpio: lp873x: Add support for General Purpose Outputs

Add driver for lp873x PMIC family GPOs. Two GPOs are supported
and can be configured in Open-drain output or Push-pull output.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 98dd47a..346e9a9 100644 (file)
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -874,6 +874,16 @@ config GPIO_LP3943
          LP3943 can be used as a GPIO expander which provides up to 16 GPIOs.
          Open drain outputs are required for this usage.
 
+config GPIO_LP873X
+       tristate "TI LP873X GPO"
+       depends on MFD_TI_LP873X
+       help
+         This driver supports the GPO on TI Lp873x PMICs. 2 GPOs are present
+         on LP873X PMICs.
+
+         This driver can also be built as a module. If so, the module will be
+          called gpio-lp873x.
+
 config GPIO_MAX77620
        tristate "GPIO support for PMIC MAX77620 and MAX20024"
        depends on MFD_MAX77620

diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 2a035ed..d60432f 100644 (file)
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_GPIO_LOONGSON)   += gpio-loongson.o
 obj-$(CONFIG_GPIO_LP3943)      += gpio-lp3943.o
 obj-$(CONFIG_GPIO_LPC18XX)     += gpio-lpc18xx.o
 obj-$(CONFIG_ARCH_LPC32XX)     += gpio-lpc32xx.o
+obj-$(CONFIG_GPIO_LP873X)      += gpio-lp873x.o
 obj-$(CONFIG_GPIO_LYNXPOINT)   += gpio-lynxpoint.o
 obj-$(CONFIG_GPIO_MAX730X)     += gpio-max730x.o
 obj-$(CONFIG_GPIO_MAX7300)     += gpio-max7300.o

diff --git a/drivers/gpio/gpio-lp873x.c b/drivers/gpio/gpio-lp873x.c
new file mode 100644 (file)
index 0000000..f10d49d
--- /dev/null
+++ b/drivers/gpio/gpio-lp873x.c
@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
+ *     Keerthy <j-keerthy@ti.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 TPS65218 driver
+ */
+
+#include <linux/gpio.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/mfd/lp873x.h>
+
+#define BITS_PER_GPO           0x4
+#define LP873X_GPO_CTRL_OD     0x2
+
+struct lp873x_gpio {
+       struct gpio_chip chip;
+       struct lp873x *lp873;
+};
+
+static int lp873x_gpio_get_direction(struct gpio_chip *chip,
+                                    unsigned int offset)
+{
+       /* This device is output only */
+       return 0;
+}
+
+static int lp873x_gpio_direction_input(struct gpio_chip *chip,
+                                      unsigned int offset)
+{
+       /* This device is output only */
+       return -EINVAL;
+}
+
+static int lp873x_gpio_direction_output(struct gpio_chip *chip,
+                                       unsigned int offset, int value)
+{
+       struct lp873x_gpio *gpio = gpiochip_get_data(chip);
+
+       /* Set the initial value */
+       return regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
+                                 BIT(offset * BITS_PER_GPO),
+                                 value ? BIT(offset * BITS_PER_GPO) : 0);
+}
+
+static int lp873x_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+       struct lp873x_gpio *gpio = gpiochip_get_data(chip);
+       int ret, val;
+
+       ret = regmap_read(gpio->lp873->regmap, LP873X_REG_GPO_CTRL, &val);
+       if (ret < 0)
+               return ret;
+
+       return val & BIT(offset * BITS_PER_GPO);
+}
+
+static void lp873x_gpio_set(struct gpio_chip *chip, unsigned int offset,
+                           int value)
+{
+       struct lp873x_gpio *gpio = gpiochip_get_data(chip);
+
+       regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
+                          BIT(offset * BITS_PER_GPO),
+                          value ? BIT(offset * BITS_PER_GPO) : 0);
+}
+
+static int lp873x_gpio_request(struct gpio_chip *gc, unsigned int offset)
+{
+       struct lp873x_gpio *gpio = gpiochip_get_data(gc);
+       int ret;
+
+       switch (offset) {
+       case 0:
+               /* No MUX Set up Needed for GPO */
+               break;
+       case 1:
+               /* Setup the CLKIN_PIN_SEL MUX to GPO2 */
+               ret = regmap_update_bits(gpio->lp873->regmap, LP873X_REG_CONFIG,
+                                        LP873X_CONFIG_CLKIN_PIN_SEL, 0);
+               if (ret)
+                       return ret;
+
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int lp873x_gpio_set_single_ended(struct gpio_chip *gc,
+                                       unsigned int offset,
+                                       enum single_ended_mode mode)
+{
+       struct lp873x_gpio *gpio = gpiochip_get_data(gc);
+
+       switch (mode) {
+       case LINE_MODE_OPEN_DRAIN:
+               return regmap_update_bits(gpio->lp873->regmap,
+                                         LP873X_REG_GPO_CTRL,
+                                         BIT(offset * BITS_PER_GPO +
+                                         LP873X_GPO_CTRL_OD),
+                                         BIT(offset * BITS_PER_GPO +
+                                         LP873X_GPO_CTRL_OD));
+       case LINE_MODE_PUSH_PULL:
+               return regmap_update_bits(gpio->lp873->regmap,
+                                         LP873X_REG_GPO_CTRL,
+                                         BIT(offset * BITS_PER_GPO +
+                                         LP873X_GPO_CTRL_OD), 0);
+       default:
+               return -ENOTSUPP;
+       }
+}
+
+static struct gpio_chip template_chip = {
+       .label                  = "lp873x-gpio",
+       .owner                  = THIS_MODULE,
+       .request                = lp873x_gpio_request,
+       .get_direction          = lp873x_gpio_get_direction,
+       .direction_input        = lp873x_gpio_direction_input,
+       .direction_output       = lp873x_gpio_direction_output,
+       .get                    = lp873x_gpio_get,
+       .set                    = lp873x_gpio_set,
+       .set_single_ended       = lp873x_gpio_set_single_ended,
+       .base                   = -1,
+       .ngpio                  = 2,
+       .can_sleep              = true,
+};
+
+static int lp873x_gpio_probe(struct platform_device *pdev)
+{
+       struct lp873x_gpio *gpio;
+       int ret;
+
+       gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
+       if (!gpio)
+               return -ENOMEM;
+
+       platform_set_drvdata(pdev, gpio);
+
+       gpio->lp873 = dev_get_drvdata(pdev->dev.parent);
+       gpio->chip = template_chip;
+       gpio->chip.parent = gpio->lp873->dev;
+
+       ret = gpiochip_add_data(&gpio->chip, gpio);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int lp873x_gpio_remove(struct platform_device *pdev)
+{
+       struct lp873x_gpio *gpio = platform_get_drvdata(pdev);
+
+       gpiochip_remove(&gpio->chip);
+
+       return 0;
+}
+
+static const struct platform_device_id lp873x_gpio_id_table[] = {
+       { "lp873x-gpio", },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, lp873x_gpio_id_table);
+
+static struct platform_driver lp873x_gpio_driver = {
+       .driver = {
+               .name = "lp873x-gpio",
+       },
+       .probe = lp873x_gpio_probe,
+       .remove = lp873x_gpio_remove,
+       .id_table = lp873x_gpio_id_table,
+};
+module_platform_driver(lp873x_gpio_driver);
+
+MODULE_AUTHOR("Keerthy <j-keerthy@ti.com>");
+MODULE_DESCRIPTION("LP873X GPIO driver");
+MODULE_LICENSE("GPL v2");