1 files changed, 420 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-regmap.c b/drivers/gpio/gpio-regmap.c
new file mode 100644
index 000000000000..e5ba38e65c10
--- /dev/null
+++ b/drivers/gpio/gpio-regmap.c
@@ -0,0 +1,420 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * regmap based generic GPIO driver
+ *
+ * Copyright 2020 Michael Walle <michael@walle.cc>
+ */
+
+#include <linux/bits.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <linux/gpio/driver.h>
+#include <linux/gpio/regmap.h>
+
+#include "gpiolib.h"
+
+struct gpio_regmap {
+	struct device *parent;
+	struct regmap *regmap;
+	struct gpio_chip gpio_chip;
+
+	int reg_stride;
+	int ngpio_per_reg;
+	unsigned int reg_dat_base;
+	unsigned int reg_set_base;
+	unsigned int reg_clr_base;
+	unsigned int reg_dir_in_base;
+	unsigned int reg_dir_out_base;
+	unsigned long *fixed_direction_output;
+
+#ifdef CONFIG_REGMAP_IRQ
+	int regmap_irq_line;
+	struct regmap_irq_chip_data *irq_chip_data;
+#endif
+
+	int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base,
+			      unsigned int offset, unsigned int *reg,
+			      unsigned int *mask);
+
+	void *driver_data;
+};
+
+static unsigned int gpio_regmap_addr(unsigned int addr)
+{
+	if (addr == GPIO_REGMAP_ADDR_ZERO)
+		return 0;
+
+	return addr;
+}
+
+static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio,
+				    unsigned int base, unsigned int offset,
+				    unsigned int *reg, unsigned int *mask)
+{
+	unsigned int line = offset % gpio->ngpio_per_reg;
+	unsigned int stride = offset / gpio->ngpio_per_reg;
+
+	*reg = base + stride * gpio->reg_stride;
+	*mask = BIT(line);
+
+	return 0;
+}
+
+static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct gpio_regmap *gpio = gpiochip_get_data(chip);
+	unsigned int base, val, reg, mask;
+	int ret;
+
+	/* we might not have an output register if we are input only */
+	if (gpio->reg_dat_base)
+		base = gpio_regmap_addr(gpio->reg_dat_base);
+	else
+		base = gpio_regmap_addr(gpio->reg_set_base);
+
+	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	if (ret)
+		return ret;
+
+	/* ensure we don't spoil any register cache with pin input values */
+	if (gpio->reg_dat_base == gpio->reg_set_base)
+		ret = regmap_read_bypassed(gpio->regmap, reg, &val);
+	else
+		ret = regmap_read(gpio->regmap, reg, &val);
+	if (ret)
+		return ret;
+
+	return !!(val & mask);
+}
+
+static int gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
+			   int val)
+{
+	struct gpio_regmap *gpio = gpiochip_get_data(chip);
+	unsigned int base = gpio_regmap_addr(gpio->reg_set_base);
+	unsigned int reg, mask, mask_val;
+	int ret;
+
+	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	if (ret)
+		return ret;
+
+	if (val)
+		mask_val = mask;
+	else
+		mask_val = 0;
+
+	/* ignore input values which shadow the old output value */
+	if (gpio->reg_dat_base == gpio->reg_set_base)
+		ret = regmap_write_bits(gpio->regmap, reg, mask, mask_val);
+	else
+		ret = regmap_update_bits(gpio->regmap, reg, mask, mask_val);
+
+	return ret;
+}
+
+static int gpio_regmap_set_with_clear(struct gpio_chip *chip,
+				      unsigned int offset, int val)
+{
+	struct gpio_regmap *gpio = gpiochip_get_data(chip);
+	unsigned int base, reg, mask;
+	int ret;
+
+	if (val)
+		base = gpio_regmap_addr(gpio->reg_set_base);
+	else
+		base = gpio_regmap_addr(gpio->reg_clr_base);
+
+	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	if (ret)
+		return ret;
+
+	return regmap_write(gpio->regmap, reg, mask);
+}
+
+static int gpio_regmap_get_direction(struct gpio_chip *chip,
+				     unsigned int offset)
+{
+	struct gpio_regmap *gpio = gpiochip_get_data(chip);
+	unsigned int base, val, reg, mask;
+	int invert, ret;
+
+	if (gpio->fixed_direction_output) {
+		if (test_bit(offset, gpio->fixed_direction_output))
+			return GPIO_LINE_DIRECTION_OUT;
+		else
+			return GPIO_LINE_DIRECTION_IN;
+	}
+
+	if (gpio->reg_dat_base && !gpio->reg_set_base)
+		return GPIO_LINE_DIRECTION_IN;
+	if (gpio->reg_set_base && !gpio->reg_dat_base)
+		return GPIO_LINE_DIRECTION_OUT;
+
+	if (gpio->reg_dir_out_base) {
+		base = gpio_regmap_addr(gpio->reg_dir_out_base);
+		invert = 0;
+	} else if (gpio->reg_dir_in_base) {
+		base = gpio_regmap_addr(gpio->reg_dir_in_base);
+		invert = 1;
+	} else {
+		return -ENOTSUPP;
+	}
+
+	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(gpio->regmap, reg, &val);
+	if (ret)
+		return ret;
+
+	if (!!(val & mask) ^ invert)
+		return GPIO_LINE_DIRECTION_OUT;
+	else
+		return GPIO_LINE_DIRECTION_IN;
+}
+
+static int gpio_regmap_set_direction(struct gpio_chip *chip,
+				     unsigned int offset, bool output)
+{
+	struct gpio_regmap *gpio = gpiochip_get_data(chip);
+	unsigned int base, val, reg, mask;
+	int invert, ret;
+
+	if (gpio->reg_dir_out_base) {
+		base = gpio_regmap_addr(gpio->reg_dir_out_base);
+		invert = 0;
+	} else if (gpio->reg_dir_in_base) {
+		base = gpio_regmap_addr(gpio->reg_dir_in_base);
+		invert = 1;
+	} else {
+		return -ENOTSUPP;
+	}
+
+	ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+	if (ret)
+		return ret;
+
+	if (invert)
+		val = output ? 0 : mask;
+	else
+		val = output ? mask : 0;
+
+	return regmap_update_bits(gpio->regmap, reg, mask, val);
+}
+
+static int gpio_regmap_direction_input(struct gpio_chip *chip,
+				       unsigned int offset)
+{
+	return gpio_regmap_set_direction(chip, offset, false);
+}
+
+static int gpio_regmap_direction_output(struct gpio_chip *chip,
+					unsigned int offset, int value)
+{
+	gpio_regmap_set(chip, offset, value);
+
+	return gpio_regmap_set_direction(chip, offset, true);
+}
+
+void *gpio_regmap_get_drvdata(struct gpio_regmap *gpio)
+{
+	return gpio->driver_data;
+}
+EXPORT_SYMBOL_GPL(gpio_regmap_get_drvdata);
+
+/**
+ * gpio_regmap_register() - Register a generic regmap GPIO controller
+ * @config: configuration for gpio_regmap
+ *
+ * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
+ */
+struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config)
+{
+	struct irq_domain *irq_domain;
+	struct gpio_regmap *gpio;
+	struct gpio_chip *chip;
+	int ret;
+
+	if (!config->parent)
+		return ERR_PTR(-EINVAL);
+
+	/* we need at least one */
+	if (!config->reg_dat_base && !config->reg_set_base)
+		return ERR_PTR(-EINVAL);
+
+	/* if we have a direction register we need both input and output */
+	if ((config->reg_dir_out_base || config->reg_dir_in_base) &&
+	    (!config->reg_dat_base || !config->reg_set_base))
+		return ERR_PTR(-EINVAL);
+
+	/* we don't support having both registers simultaneously for now */
+	if (config->reg_dir_out_base && config->reg_dir_in_base)
+		return ERR_PTR(-EINVAL);
+
+	gpio = kzalloc(sizeof(*gpio), GFP_KERNEL);
+	if (!gpio)
+		return ERR_PTR(-ENOMEM);
+
+	gpio->parent = config->parent;
+	gpio->driver_data = config->drvdata;
+	gpio->regmap = config->regmap;
+	gpio->reg_dat_base = config->reg_dat_base;
+	gpio->reg_set_base = config->reg_set_base;
+	gpio->reg_clr_base = config->reg_clr_base;
+	gpio->reg_dir_in_base = config->reg_dir_in_base;
+	gpio->reg_dir_out_base = config->reg_dir_out_base;
+
+	chip = &gpio->gpio_chip;
+	chip->parent = config->parent;
+	chip->fwnode = config->fwnode;
+	chip->base = -1;
+	chip->names = config->names;
+	chip->label = config->label ?: dev_name(config->parent);
+	chip->can_sleep = regmap_might_sleep(config->regmap);
+	chip->init_valid_mask = config->init_valid_mask;
+
+	chip->request = gpiochip_generic_request;
+	chip->free = gpiochip_generic_free;
+	chip->get = gpio_regmap_get;
+	if (gpio->reg_set_base && gpio->reg_clr_base)
+		chip->set = gpio_regmap_set_with_clear;
+	else if (gpio->reg_set_base)
+		chip->set = gpio_regmap_set;
+
+	chip->get_direction = gpio_regmap_get_direction;
+	if (gpio->reg_dir_in_base || gpio->reg_dir_out_base) {
+		chip->direction_input = gpio_regmap_direction_input;
+		chip->direction_output = gpio_regmap_direction_output;
+	}
+
+	chip->ngpio = config->ngpio;
+	if (!chip->ngpio) {
+		ret = gpiochip_get_ngpios(chip, chip->parent);
+		if (ret)
+			goto err_free_gpio;
+	}
+
+	if (config->fixed_direction_output) {
+		gpio->fixed_direction_output = bitmap_alloc(chip->ngpio,
+							    GFP_KERNEL);
+		if (!gpio->fixed_direction_output) {
+			ret = -ENOMEM;
+			goto err_free_gpio;
+		}
+		bitmap_copy(gpio->fixed_direction_output,
+			    config->fixed_direction_output, chip->ngpio);
+	}
+
+	/* if not set, assume there is only one register */
+	gpio->ngpio_per_reg = config->ngpio_per_reg;
+	if (!gpio->ngpio_per_reg)
+		gpio->ngpio_per_reg = config->ngpio;
+
+	/* if not set, assume they are consecutive */
+	gpio->reg_stride = config->reg_stride;
+	if (!gpio->reg_stride)
+		gpio->reg_stride = 1;
+
+	gpio->reg_mask_xlate = config->reg_mask_xlate;
+	if (!gpio->reg_mask_xlate)
+		gpio->reg_mask_xlate = gpio_regmap_simple_xlate;
+
+	ret = gpiochip_add_data(chip, gpio);
+	if (ret < 0)
+		goto err_free_bitmap;
+
+#ifdef CONFIG_REGMAP_IRQ
+	if (config->regmap_irq_chip) {
+		gpio->regmap_irq_line = config->regmap_irq_line;
+		ret = regmap_add_irq_chip_fwnode(dev_fwnode(config->parent), config->regmap,
+						 config->regmap_irq_line, config->regmap_irq_flags,
+						 0, config->regmap_irq_chip, &gpio->irq_chip_data);
+		if (ret)
+			goto err_free_bitmap;
+
+		irq_domain = regmap_irq_get_domain(gpio->irq_chip_data);
+	} else
+#endif
+	irq_domain = config->irq_domain;
+
+	if (irq_domain) {
+		ret = gpiochip_irqchip_add_domain(chip, irq_domain);
+		if (ret)
+			goto err_remove_gpiochip;
+	}
+
+	return gpio;
+
+err_remove_gpiochip:
+	gpiochip_remove(chip);
+err_free_bitmap:
+	bitmap_free(gpio->fixed_direction_output);
+err_free_gpio:
+	kfree(gpio);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(gpio_regmap_register);
+
+/**
+ * gpio_regmap_unregister() - Unregister a generic regmap GPIO controller
+ * @gpio: gpio_regmap device to unregister
+ */
+void gpio_regmap_unregister(struct gpio_regmap *gpio)
+{
+#ifdef CONFIG_REGMAP_IRQ
+	if (gpio->irq_chip_data)
+		regmap_del_irq_chip(gpio->regmap_irq_line, gpio->irq_chip_data);
+#endif
+
+	gpiochip_remove(&gpio->gpio_chip);
+	bitmap_free(gpio->fixed_direction_output);
+	kfree(gpio);
+}
+EXPORT_SYMBOL_GPL(gpio_regmap_unregister);
+
+static void devm_gpio_regmap_unregister(void *res)
+{
+	gpio_regmap_unregister(res);
+}
+
+/**
+ * devm_gpio_regmap_register() - resource managed gpio_regmap_register()
+ * @dev: device that is registering this GPIO device
+ * @config: configuration for gpio_regmap
+ *
+ * Managed gpio_regmap_register(). For generic regmap GPIO device registered by
+ * this function, gpio_regmap_unregister() is automatically called on driver
+ * detach. See gpio_regmap_register() for more information.
+ *
+ * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
+ */
+struct gpio_regmap *devm_gpio_regmap_register(struct device *dev,
+					      const struct gpio_regmap_config *config)
+{
+	struct gpio_regmap *gpio;
+	int ret;
+
+	gpio = gpio_regmap_register(config);
+
+	if (IS_ERR(gpio))
+		return gpio;
+
+	ret = devm_add_action_or_reset(dev, devm_gpio_regmap_unregister, gpio);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return gpio;
+}
+EXPORT_SYMBOL_GPL(devm_gpio_regmap_register);
+
+MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
+MODULE_DESCRIPTION("GPIO generic regmap driver core");
+MODULE_LICENSE("GPL");