[PATCH v2 3/3] pinctrl: da9062: add driver support

[Marco Felsch <m.felsch@xxxxxxxxxxxxxx>]

The DA9062 is a mfd pmic device which supports 5 GPIOs. The GPIOs can
be used as input, output or have a special use-case.

The patch adds the support for the normal input/output use-case.

Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
---
Changelog:

v2:
- fix minor style issue
- move from drivers/gpio to drivers/pinctrl
- Fix spelling issue
- rename local gpio_dir to gpio_mode
- Add datasheet reference and TODO notes
- move gpio to mfd-root node to avoid hierarchical interrupt chips
- Add gpio-controller property check
- remove of_device_id since we drop the gpio of-subnode
- Drop da9062_gpio_get_hwgpio
---
 drivers/pinctrl/Kconfig          |  12 ++
 drivers/pinctrl/Makefile         |   1 +
 drivers/pinctrl/pinctrl-da9062.c | 272 +++++++++++++++++++++++++++++++
 3 files changed, 285 insertions(+)
 create mode 100644 drivers/pinctrl/pinctrl-da9062.c

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index b372419d61f2..977787c158cc 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -126,6 +126,18 @@ config PINCTRL_DA850_PUPD
 	  Driver for TI DA850/OMAP-L138/AM18XX pinconf. Used to control
 	  pullup/pulldown pin groups.
 
+config PINCTRL_DA9062
+	tristate "Dialog Semiconductor DA9062 PMIC pinctrl and GPIO Support"
+	depends on MFD_DA9062
+	select GPIOLIB
+	help
+	  The Dialog DA9062 PMIC provides multiple GPIOs that can be muxed for
+	  different functions. This driver bundles a pinctrl driver to select the
+	  function muxing and a GPIO driver to handle the GPIO when the GPIO
+	  function is selected.
+
+	  Say yes to enable pinctrl and GPIO support for the DA9062 PMIC.
+
 config PINCTRL_DIGICOLOR
 	bool
 	depends on OF && (ARCH_DIGICOLOR || COMPILE_TEST)
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index ac537fdbc998..2397684cbe11 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_PINCTRL_AT91PIO4)	+= pinctrl-at91-pio4.o
 obj-$(CONFIG_PINCTRL_AMD)	+= pinctrl-amd.o
 obj-$(CONFIG_PINCTRL_BM1880)	+= pinctrl-bm1880.o
 obj-$(CONFIG_PINCTRL_DA850_PUPD) += pinctrl-da850-pupd.o
+obj-$(CONFIG_PINCTRL_DA9062)	+= pinctrl-da9062.o
 obj-$(CONFIG_PINCTRL_DIGICOLOR)	+= pinctrl-digicolor.o
 obj-$(CONFIG_PINCTRL_FALCON)	+= pinctrl-falcon.o
 obj-$(CONFIG_PINCTRL_GEMINI)	+= pinctrl-gemini.o
diff --git a/drivers/pinctrl/pinctrl-da9062.c b/drivers/pinctrl/pinctrl-da9062.c
new file mode 100644
index 000000000000..35ea8b488162
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-da9062.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Dialog DA9062 pinctrl and GPIO driver.
+ * Based on DA9055 GPIO driver.
+ *
+ * TODO:
+ *   - add pinmux and pinctrl support (gpio alternate mode)
+ *
+ * Documents:
+ * [1] https://www.dialog-semiconductor.com/sites/default/files/da9062_datasheet_3v6.pdf
+ *
+ * Copyright (C) 2019 Pengutronix, Marco Felsch <kernel@xxxxxxxxxxxxxx>
+ */
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/gpio/driver.h>
+
+#include <linux/mfd/da9062/core.h>
+#include <linux/mfd/da9062/registers.h>
+
+#include <../gpio/gpiolib.h>
+
+#define DA9062_TYPE(offset)		(4 * (offset % 2))
+#define DA9062_PIN_SHIFT(offset)	(4 * (offset % 2))
+#define DA9062_PIN_ALTERNATE		0x00 /* gpio alternate mode */
+#define DA9062_PIN_GPI			0x01 /* gpio in */
+#define DA9062_PIN_GPO_OD		0x02 /* gpio out open-drain */
+#define DA9062_PIN_GPO_PP		0x03 /* gpio out push-pull */
+#define DA9062_GPIO_NUM			5
+
+struct da9062_pctl {
+	struct da9062 *da9062;
+	struct gpio_chip gc;
+};
+
+static int da9062_pctl_get_pin_mode(struct regmap *regmap, unsigned int offset)
+{
+	int ret, val;
+
+	ret = regmap_read(regmap, DA9062AA_GPIO_0_1 + (offset >> 1), &val);
+	if (ret < 0)
+		return ret;
+
+	val >>= DA9062_PIN_SHIFT(offset);
+	val &= DA9062AA_GPIO0_PIN_MASK;
+
+	return val;
+}
+
+static int da9062_pctl_set_pin_mode(struct regmap *regmap, unsigned int offset,
+				    unsigned int mode)
+{
+	unsigned int mask;
+
+	mode &= DA9062AA_GPIO0_PIN_MASK;
+	mode <<= DA9062_PIN_SHIFT(offset);
+	mask = DA9062AA_GPIO0_PIN_MASK << DA9062_PIN_SHIFT(offset);
+
+	return regmap_update_bits(regmap, DA9062AA_GPIO_0_1 + (offset >> 1),
+				  mask, mode);
+}
+
+static int da9062_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+	struct da9062_pctl *pctl = gpiochip_get_data(gc);
+	struct regmap *regmap = pctl->da9062->regmap;
+	int gpio_mode, val;
+	int ret;
+
+	gpio_mode = da9062_pctl_get_pin_mode(regmap, offset);
+	if (gpio_mode < 0)
+		return gpio_mode;
+
+	switch (gpio_mode) {
+	case DA9062_PIN_ALTERNATE:
+		return -ENOTSUPP;
+	case DA9062_PIN_GPI:
+		ret = regmap_read(regmap, DA9062AA_STATUS_B, &val);
+		if (ret < 0)
+			return ret;
+		break;
+	case DA9062_PIN_GPO_OD:
+	case DA9062_PIN_GPO_PP:
+		ret = regmap_read(regmap, DA9062AA_GPIO_MODE0_4, &val);
+		if (ret < 0)
+			return ret;
+	}
+
+	return val & BIT(offset);
+}
+
+static void da9062_gpio_set(struct gpio_chip *gc, unsigned int offset,
+			    int value)
+{
+	struct da9062_pctl *pctl = gpiochip_get_data(gc);
+	struct regmap *regmap = pctl->da9062->regmap;
+
+	regmap_update_bits(regmap, DA9062AA_GPIO_MODE0_4, BIT(offset),
+			   value << offset);
+}
+
+static int da9062_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	struct da9062_pctl *pctl = gpiochip_get_data(gc);
+	struct regmap *regmap = pctl->da9062->regmap;
+	int gpio_mode;
+
+	gpio_mode = da9062_pctl_get_pin_mode(regmap, offset);
+	if (gpio_mode < 0)
+		return gpio_mode;
+
+	switch (gpio_mode) {
+	case DA9062_PIN_ALTERNATE:
+		return -ENOTSUPP;
+	case DA9062_PIN_GPI:
+		return 1;
+	case DA9062_PIN_GPO_OD:
+	case DA9062_PIN_GPO_PP:
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int da9062_gpio_direction_input(struct gpio_chip *gc,
+				       unsigned int offset)
+{
+	struct da9062_pctl *pctl = gpiochip_get_data(gc);
+	struct regmap *regmap = pctl->da9062->regmap;
+	struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
+	unsigned int gpi_type;
+	int ret;
+
+	ret = da9062_pctl_set_pin_mode(regmap, offset, DA9062_PIN_GPI);
+	if (ret)
+		return ret;
+
+	/*
+	 * If the gpio is active low we should set it in hw too. No worries
+	 * about gpio_get() because we read and return the gpio-level. So the
+	 * gpiolib active_low handling is still correct.
+	 *
+	 * 0 - active low, 1 - active high
+	 */
+	gpi_type = !gpiod_is_active_low(desc);
+
+	return regmap_update_bits(regmap, DA9062AA_GPIO_0_1 + (offset >> 1),
+				DA9062AA_GPIO0_TYPE_MASK << DA9062_TYPE(offset),
+				gpi_type << DA9062_TYPE(offset));
+}
+
+static int da9062_gpio_direction_output(struct gpio_chip *gc,
+					unsigned int offset, int value)
+{
+	/* Push-Pull / Open-Drain options are configured during set_config */
+	da9062_gpio_set(gc, offset, value);
+
+	return 0;
+}
+
+static int da9062_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
+				  unsigned long config)
+{
+	struct da9062_pctl *pctl = gpiochip_get_data(gc);
+	struct regmap *regmap = pctl->da9062->regmap;
+	int gpio_mode;
+
+	/*
+	 * We need to meet the following restrictions [1, Figure 18]:
+	 * - PIN_CONFIG_BIAS_PULL_DOWN -> only allowed of the pin is used as
+	 *				  gpio input
+	 * - PIN_CONFIG_BIAS_PULL_UP   -> only allowed of the pin is used as
+	 *				  gpio output open-drain.
+	 */
+
+	switch (pinconf_to_config_param(config)) {
+	case PIN_CONFIG_BIAS_PULL_DOWN:
+		gpio_mode = da9062_pctl_get_pin_mode(regmap, offset);
+		if (gpio_mode < 0)
+			return -EINVAL;
+		else if (gpio_mode != DA9062_PIN_GPI)
+			return -ENOTSUPP;
+		return regmap_update_bits(regmap, DA9062AA_CONFIG_K,
+					  BIT(offset), BIT(offset));
+	case PIN_CONFIG_BIAS_PULL_UP:
+		gpio_mode = da9062_pctl_get_pin_mode(regmap, offset);
+		if (gpio_mode < 0)
+			return -EINVAL;
+		else if (gpio_mode != DA9062_PIN_GPO_OD)
+			return -ENOTSUPP;
+		return regmap_update_bits(regmap, DA9062AA_CONFIG_K,
+					  BIT(offset), BIT(offset));
+	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+		return da9062_pctl_set_pin_mode(regmap, offset,
+						DA9062_PIN_GPO_OD);
+	case PIN_CONFIG_DRIVE_PUSH_PULL:
+		return da9062_pctl_set_pin_mode(regmap, offset,
+						DA9062_PIN_GPO_PP);
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+static int da9062_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
+{
+	struct da9062_pctl *pctl = gpiochip_get_data(gc);
+	struct da9062 *da9062 = pctl->da9062;
+
+	return regmap_irq_get_virq(da9062->regmap_irq,
+				   DA9062_IRQ_GPI0 + offset);
+}
+
+static const struct gpio_chip reference_gc = {
+	.owner = THIS_MODULE,
+	.get = da9062_gpio_get,
+	.set = da9062_gpio_set,
+	.get_direction = da9062_gpio_get_direction,
+	.direction_input = da9062_gpio_direction_input,
+	.direction_output = da9062_gpio_direction_output,
+	.set_config = da9062_gpio_set_config,
+	.to_irq = da9062_gpio_to_irq,
+	.can_sleep = true,
+	.ngpio = DA9062_GPIO_NUM,
+	.base = -1,
+};
+
+static int da9062_pctl_probe(struct platform_device *pdev)
+{
+	struct device *parent = pdev->dev.parent;
+	struct da9062_pctl *pctl;
+
+	pctl = devm_kzalloc(&pdev->dev, sizeof(*pctl), GFP_KERNEL);
+	if (!pctl)
+		return -ENOMEM;
+
+	pctl->da9062 = dev_get_drvdata(parent);
+	if (!pctl->da9062)
+		return -EINVAL;
+
+	if (!device_property_present(parent, "gpio-controller"))
+		return 0;
+
+	/*
+	 * Currently the driver handles only the GPIO support. The
+	 * pinctrl/pinmux support can be added later if needed.
+	 */
+	pctl->gc = reference_gc;
+	pctl->gc.label = dev_name(&pdev->dev);
+	pctl->gc.parent = &pdev->dev;
+#ifdef CONFIG_OF_GPIO
+	pctl->gc.of_node = parent->of_node;
+#endif
+
+	platform_set_drvdata(pdev, pctl);
+
+	return devm_gpiochip_add_data(&pdev->dev, &pctl->gc, pctl);
+}
+
+static struct platform_driver da9062_pctl_driver = {
+	.probe = da9062_pctl_probe,
+	.driver = {
+		.name	= "da9062-gpio",
+	},
+};
+module_platform_driver(da9062_pctl_driver);
+
+MODULE_AUTHOR("Marco Felsch <kernel@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("DA9062 PMIC pinctrl and GPIO Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:da9062-gpio");
-- 
2.20.1