// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019 Bootlin
* Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
*/
#include <linux/err.h>
#include <linux/gpio/driver.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#define LOGICVC_CTRL_REG 0x40
#define LOGICVC_CTRL_GPIO_SHIFT 11
#define LOGICVC_CTRL_GPIO_BITS 5
#define LOGICVC_POWER_CTRL_REG 0x78
#define LOGICVC_POWER_CTRL_GPIO_SHIFT 0
#define LOGICVC_POWER_CTRL_GPIO_BITS 4
struct logicvc_gpio {
struct gpio_chip chip;
struct regmap *regmap;
};
static void logicvc_gpio_offset(struct logicvc_gpio *logicvc, unsigned offset,
unsigned int *reg, unsigned int *bit)
{
if (offset >= LOGICVC_CTRL_GPIO_BITS) {
*reg = LOGICVC_POWER_CTRL_REG;
/* To the (virtual) power ctrl offset. */
offset -= LOGICVC_CTRL_GPIO_BITS;
/* To the actual bit offset in reg. */
offset += LOGICVC_POWER_CTRL_GPIO_SHIFT;
} else {
*reg = LOGICVC_CTRL_REG;
/* To the actual bit offset in reg. */
offset += LOGICVC_CTRL_GPIO_SHIFT;
}
*bit = BIT(offset);
}
static int logicvc_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct logicvc_gpio *logicvc = gpiochip_get_data(chip);
unsigned int reg, bit, value;
int ret;
logicvc_gpio_offset(logicvc, offset, ®, &bit);
ret = regmap_read(logicvc->regmap, reg, &value);
if (ret)
return ret;
return !!(value & bit);
}
static void logicvc_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct logicvc_gpio *logicvc = gpiochip_get_data(chip);
unsigned int reg, bit;
logicvc_gpio_offset(logicvc, offset, ®, &bit);
regmap_update_bits(logicvc->regmap, reg, bit, value ? bit : 0);
}
static int logicvc_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
/* Pins are always configured as output, so just set the value. */
logicvc_gpio_set(chip, offset, value);
return 0;
}
static struct regmap_config logicvc_gpio_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
.name = "logicvc-gpio",
};
static int logicvc_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *of_node = dev->of_node;
struct logicvc_gpio *logicvc;
int ret;
logicvc = devm_kzalloc(dev, sizeof(*logicvc), GFP_KERNEL);
if (!logicvc)
return -ENOMEM;
/* Try to get regmap from parent first. */
logicvc->regmap = syscon_node_to_regmap(of_node->parent);
/* Grab our own regmap if that fails. */
if (IS_ERR(logicvc->regmap)) {
struct resource res;
void __iomem *base;
ret = of_address_to_resource(of_node, 0, &res);
if (ret) {
dev_err(dev, "Failed to get resource from address\n");
return ret;
}
base = devm_ioremap_resource(dev, &res);
if (IS_ERR(base))
return PTR_ERR(base);
logicvc_gpio_regmap_config.max_register = resource_size(&res) -
logicvc_gpio_regmap_config.reg_stride;
logicvc->regmap =
devm_regmap_init_mmio(dev, base,
&logicvc_gpio_regmap_config);
if (IS_ERR(logicvc->regmap)) {
dev_err(dev, "Failed to create regmap for I/O\n");
return PTR_ERR(logicvc->regmap);
}
}
logicvc->chip.parent = dev;
logicvc->chip.owner = THIS_MODULE;
logicvc->chip.label = dev_name(dev);
logicvc->chip.base = -1;
logicvc->chip.ngpio = LOGICVC_CTRL_GPIO_BITS +
LOGICVC_POWER_CTRL_GPIO_BITS;
logicvc->chip.get = logicvc_gpio_get;
logicvc->chip.set = logicvc_gpio_set;
logicvc->chip.direction_output = logicvc_gpio_direction_output;
platform_set_drvdata(pdev, logicvc);
return devm_gpiochip_add_data(dev, &logicvc->chip, logicvc);
}
static const struct of_device_id logicivc_gpio_of_table[] = {
{
.compatible = "xylon,logicvc-3.02.a-gpio",
},
{ }
};
MODULE_DEVICE_TABLE(of, logicivc_gpio_of_table);
static struct platform_driver logicvc_gpio_driver = {
.driver = {
.name = "gpio-logicvc",
.of_match_table = logicivc_gpio_of_table,
},
.probe = logicvc_gpio_probe,
};
module_platform_driver(logicvc_gpio_driver);
MODULE_AUTHOR("Paul Kocialkowski <paul.kocialkowski@bootlin.com>");
MODULE_DESCRIPTION("Xylon LogiCVC GPIO driver");
MODULE_LICENSE("GPL");
