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path: root/drivers/gpio/gpio-regmap.c
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-rw-r--r--drivers/gpio/gpio-regmap.c345
1 files changed, 345 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-regmap.c b/drivers/gpio/gpio-regmap.c
new file mode 100644
index 0000000000..c08c8e5288
--- /dev/null
+++ b/drivers/gpio/gpio-regmap.c
@@ -0,0 +1,345 @@
+// 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>
+
+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;
+
+ 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;
+
+ ret = regmap_read(gpio->regmap, reg, &val);
+ if (ret)
+ return ret;
+
+ return !!(val & mask);
+}
+
+static void 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;
+
+ gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+ if (val)
+ regmap_update_bits(gpio->regmap, reg, mask, mask);
+ else
+ regmap_update_bits(gpio->regmap, reg, mask, 0);
+}
+
+static void 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;
+
+ if (val)
+ base = gpio_regmap_addr(gpio->reg_set_base);
+ else
+ base = gpio_regmap_addr(gpio->reg_clr_base);
+
+ gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
+ 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->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 -EOPNOTSUPP;
+ }
+
+ 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 -EOPNOTSUPP;
+ }
+
+ 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 gpio_regmap *gpio;
+ struct gpio_chip *chip;
+ int ret;
+
+ if (!config->parent)
+ return ERR_PTR(-EINVAL);
+
+ if (!config->ngpio)
+ 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->ngpio_per_reg = config->ngpio_per_reg;
+ gpio->reg_stride = config->reg_stride;
+ gpio->reg_mask_xlate = config->reg_mask_xlate;
+ 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;
+
+ /* if not set, assume there is only one register */
+ if (!gpio->ngpio_per_reg)
+ gpio->ngpio_per_reg = config->ngpio;
+
+ /* if not set, assume they are consecutive */
+ if (!gpio->reg_stride)
+ gpio->reg_stride = 1;
+
+ if (!gpio->reg_mask_xlate)
+ gpio->reg_mask_xlate = gpio_regmap_simple_xlate;
+
+ chip = &gpio->gpio_chip;
+ chip->parent = config->parent;
+ chip->fwnode = config->fwnode;
+ chip->base = -1;
+ chip->ngpio = config->ngpio;
+ chip->names = config->names;
+ chip->label = config->label ?: dev_name(config->parent);
+ chip->can_sleep = regmap_might_sleep(config->regmap);
+
+ 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;
+ }
+
+ ret = gpiochip_add_data(chip, gpio);
+ if (ret < 0)
+ goto err_free_gpio;
+
+ if (config->irq_domain) {
+ ret = gpiochip_irqchip_add_domain(chip, config->irq_domain);
+ if (ret)
+ goto err_remove_gpiochip;
+ }
+
+ return gpio;
+
+err_remove_gpiochip:
+ gpiochip_remove(chip);
+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)
+{
+ gpiochip_remove(&gpio->gpio_chip);
+ 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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-15 23:39:28 +0000