--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * GPIO driver for TI TPS65219 PMICs
+ *
+ * Copyright (C) 2022 Texas Instruments Incorporated - http://www.ti.com/
+ */
+
+#include <linux/bits.h>
+#include <linux/gpio/driver.h>
+#include <linux/mfd/tps65219.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define TPS65219_GPIO0_DIR_MASK BIT(3)
+#define TPS65219_GPIO0_OFFSET 2
+#define TPS65219_GPIO0_IDX 0
+#define TPS65219_GPIO_DIR_IN 1
+#define TPS65219_GPIO_DIR_OUT 0
+
+struct tps65219_gpio {
+ struct gpio_chip gpio_chip;
+ struct tps65219 *tps;
+};
+
+static int tps65219_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+ struct tps65219_gpio *gpio = gpiochip_get_data(gc);
+ int ret, val;
+
+ if (offset != TPS65219_GPIO0_IDX)
+ return GPIO_LINE_DIRECTION_OUT;
+
+ ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG, &val);
+ if (ret)
+ return ret;
+
+ return !!(val & TPS65219_GPIO0_DIR_MASK);
+}
+
+static int tps65219_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+ struct tps65219_gpio *gpio = gpiochip_get_data(gc);
+ struct device *dev = gpio->tps->dev;
+ int ret, val;
+
+ if (offset != TPS65219_GPIO0_IDX) {
+ dev_err(dev, "GPIO%d is output only, cannot get\n", offset);
+ return -ENOTSUPP;
+ }
+
+ ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_CTRL, &val);
+ if (ret)
+ return ret;
+
+ ret = !!(val & BIT(TPS65219_MFP_GPIO_STATUS_MASK));
+ dev_warn(dev, "GPIO%d = %d, MULTI_DEVICE_ENABLE, not a standard GPIO\n", offset, ret);
+
+ /*
+ * Depending on NVM config, return an error if direction is output, otherwise the GPIO0
+ * status bit.
+ */
+
+ if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_OUT)
+ return -ENOTSUPP;
+
+ return ret;
+}
+
+static void tps65219_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ struct tps65219_gpio *gpio = gpiochip_get_data(gc);
+ struct device *dev = gpio->tps->dev;
+ int v, mask, bit;
+
+ bit = (offset == TPS65219_GPIO0_IDX) ? TPS65219_GPIO0_OFFSET : offset - 1;
+
+ mask = BIT(bit);
+ v = value ? mask : 0;
+
+ if (regmap_update_bits(gpio->tps->regmap, TPS65219_REG_GENERAL_CONFIG, mask, v))
+ dev_err(dev, "GPIO%d, set to value %d failed.\n", offset, value);
+}
+
+static int tps65219_gpio_change_direction(struct gpio_chip *gc, unsigned int offset,
+ unsigned int direction)
+{
+ struct tps65219_gpio *gpio = gpiochip_get_data(gc);
+ struct device *dev = gpio->tps->dev;
+
+ /*
+ * Documentation is stating that GPIO0 direction must not be changed in Linux:
+ * Table 8-34. MFP_1_CONFIG(3): MULTI_DEVICE_ENABLE, should only be changed in INITIALIZE
+ * state (prior to ON Request).
+ * Set statically by NVM, changing direction in application can cause a hang.
+ * Below can be used for test purpose only.
+ */
+
+ if (IS_ENABLED(CONFIG_DEBUG_GPIO)) {
+ int ret = regmap_update_bits(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG,
+ TPS65219_GPIO0_DIR_MASK, direction);
+ if (ret) {
+ dev_err(dev,
+ "GPIO DEBUG enabled: Fail to change direction to %u for GPIO%d.\n",
+ direction, offset);
+ return ret;
+ }
+ }
+
+ dev_err(dev,
+ "GPIO%d direction set by NVM, change to %u failed, not allowed by specification\n",
+ offset, direction);
+
+ return -ENOTSUPP;
+}
+
+static int tps65219_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
+{
+ struct tps65219_gpio *gpio = gpiochip_get_data(gc);
+ struct device *dev = gpio->tps->dev;
+
+ if (offset != TPS65219_GPIO0_IDX) {
+ dev_err(dev, "GPIO%d is output only, cannot change to input\n", offset);
+ return -ENOTSUPP;
+ }
+
+ if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_IN)
+ return 0;
+
+ return tps65219_gpio_change_direction(gc, offset, TPS65219_GPIO_DIR_IN);
+}
+
+static int tps65219_gpio_direction_output(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ tps65219_gpio_set(gc, offset, value);
+ if (offset != TPS65219_GPIO0_IDX)
+ return 0;
+
+ if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_OUT)
+ return 0;
+
+ return tps65219_gpio_change_direction(gc, offset, TPS65219_GPIO_DIR_OUT);
+}
+
+static const struct gpio_chip tps65219_template_chip = {
+ .label = "tps65219-gpio",
+ .owner = THIS_MODULE,
+ .get_direction = tps65219_gpio_get_direction,
+ .direction_input = tps65219_gpio_direction_input,
+ .direction_output = tps65219_gpio_direction_output,
+ .get = tps65219_gpio_get,
+ .set = tps65219_gpio_set,
+ .base = -1,
+ .ngpio = 3,
+ .can_sleep = true,
+};
+
+static int tps65219_gpio_probe(struct platform_device *pdev)
+{
+ struct tps65219 *tps = dev_get_drvdata(pdev->dev.parent);
+ struct tps65219_gpio *gpio;
+
+ gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
+ if (!gpio)
+ return -ENOMEM;
+
+ gpio->tps = tps;
+ gpio->gpio_chip = tps65219_template_chip;
+ gpio->gpio_chip.parent = tps->dev;
+
+ return devm_gpiochip_add_data(&pdev->dev, &gpio->gpio_chip, gpio);
+}
+
+static struct platform_driver tps65219_gpio_driver = {
+ .driver = {
+ .name = "tps65219-gpio",
+ },
+ .probe = tps65219_gpio_probe,
+};
+module_platform_driver(tps65219_gpio_driver);
+
+MODULE_ALIAS("platform:tps65219-gpio");
+MODULE_AUTHOR("Jonathan Cormier <jcormier@criticallink.com>");
+MODULE_DESCRIPTION("TPS65219 GPIO driver");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-rpi.git / commitdiff