Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 195 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-ts4900.c b/drivers/gpio/gpio-ts4900.c
new file mode 100644
index 0000000000..0f6397b77c
--- /dev/null
+++ b/drivers/gpio/gpio-ts4900.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Digital I/O driver for Technologic Systems I2C FPGA Core
+ *
+ * Copyright (C) 2015, 2018 Technologic Systems
+ * Copyright (C) 2016 Savoir-Faire Linux
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#define DEFAULT_PIN_NUMBER	32
+/*
+ * Register bits used by the GPIO device
+ * Some boards, such as TS-7970 do not have a separate input bit
+ */
+#define TS4900_GPIO_OE		0x01
+#define TS4900_GPIO_OUT		0x02
+#define TS4900_GPIO_IN		0x04
+#define TS7970_GPIO_IN		0x02
+
+struct ts4900_gpio_priv {
+	struct regmap *regmap;
+	struct gpio_chip gpio_chip;
+	unsigned int input_bit;
+};
+
+static int ts4900_gpio_get_direction(struct gpio_chip *chip,
+				     unsigned int offset)
+{
+	struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
+	unsigned int reg;
+
+	regmap_read(priv->regmap, offset, &reg);
+
+	if (reg & TS4900_GPIO_OE)
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return GPIO_LINE_DIRECTION_IN;
+}
+
+static int ts4900_gpio_direction_input(struct gpio_chip *chip,
+				       unsigned int offset)
+{
+	struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
+
+	/*
+	 * Only clear the OE bit here, requires a RMW. Prevents a potential issue
+	 * with OE and DAT getting to the physical pin at different times.
+	 */
+	return regmap_update_bits(priv->regmap, offset, TS4900_GPIO_OE, 0);
+}
+
+static int ts4900_gpio_direction_output(struct gpio_chip *chip,
+					unsigned int offset, int value)
+{
+	struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
+	unsigned int reg;
+	int ret;
+
+	/*
+	 * If changing from an input to an output, we need to first set the
+	 * GPIO's DAT bit to what is requested and then set the OE bit. This
+	 * prevents a glitch that can occur on the IO line.
+	 */
+	regmap_read(priv->regmap, offset, &reg);
+	if (!(reg & TS4900_GPIO_OE)) {
+		if (value)
+			reg = TS4900_GPIO_OUT;
+		else
+			reg &= ~TS4900_GPIO_OUT;
+
+		regmap_write(priv->regmap, offset, reg);
+	}
+
+	if (value)
+		ret = regmap_write(priv->regmap, offset, TS4900_GPIO_OE |
+							 TS4900_GPIO_OUT);
+	else
+		ret = regmap_write(priv->regmap, offset, TS4900_GPIO_OE);
+
+	return ret;
+}
+
+static int ts4900_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
+	unsigned int reg;
+
+	regmap_read(priv->regmap, offset, &reg);
+
+	return !!(reg & priv->input_bit);
+}
+
+static void ts4900_gpio_set(struct gpio_chip *chip, unsigned int offset,
+			    int value)
+{
+	struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
+
+	if (value)
+		regmap_update_bits(priv->regmap, offset, TS4900_GPIO_OUT,
+				   TS4900_GPIO_OUT);
+	else
+		regmap_update_bits(priv->regmap, offset, TS4900_GPIO_OUT, 0);
+}
+
+static const struct regmap_config ts4900_regmap_config = {
+	.reg_bits = 16,
+	.val_bits = 8,
+};
+
+static const struct gpio_chip template_chip = {
+	.label			= "ts4900-gpio",
+	.owner			= THIS_MODULE,
+	.get_direction		= ts4900_gpio_get_direction,
+	.direction_input	= ts4900_gpio_direction_input,
+	.direction_output	= ts4900_gpio_direction_output,
+	.get			= ts4900_gpio_get,
+	.set			= ts4900_gpio_set,
+	.base			= -1,
+	.can_sleep		= true,
+};
+
+static const struct of_device_id ts4900_gpio_of_match_table[] = {
+	{
+		.compatible = "technologic,ts4900-gpio",
+		.data = (void *)TS4900_GPIO_IN,
+	}, {
+		.compatible = "technologic,ts7970-gpio",
+		.data = (void *)TS7970_GPIO_IN,
+	},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ts4900_gpio_of_match_table);
+
+static int ts4900_gpio_probe(struct i2c_client *client)
+{
+	struct ts4900_gpio_priv *priv;
+	u32 ngpio;
+	int ret;
+
+	if (of_property_read_u32(client->dev.of_node, "ngpios", &ngpio))
+		ngpio = DEFAULT_PIN_NUMBER;
+
+	priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->gpio_chip = template_chip;
+	priv->gpio_chip.label = "ts4900-gpio";
+	priv->gpio_chip.ngpio = ngpio;
+	priv->gpio_chip.parent = &client->dev;
+	priv->input_bit = (uintptr_t)of_device_get_match_data(&client->dev);
+
+	priv->regmap = devm_regmap_init_i2c(client, &ts4900_regmap_config);
+	if (IS_ERR(priv->regmap)) {
+		ret = PTR_ERR(priv->regmap);
+		dev_err(&client->dev, "Failed to allocate register map: %d\n",
+			ret);
+		return ret;
+	}
+
+	ret = devm_gpiochip_add_data(&client->dev, &priv->gpio_chip, priv);
+	if (ret < 0) {
+		dev_err(&client->dev, "Unable to register gpiochip\n");
+		return ret;
+	}
+
+	i2c_set_clientdata(client, priv);
+
+	return 0;
+}
+
+static const struct i2c_device_id ts4900_gpio_id_table[] = {
+	{ "ts4900-gpio", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, ts4900_gpio_id_table);
+
+static struct i2c_driver ts4900_gpio_driver = {
+	.driver = {
+		.name = "ts4900-gpio",
+		.of_match_table = ts4900_gpio_of_match_table,
+	},
+	.probe = ts4900_gpio_probe,
+	.id_table = ts4900_gpio_id_table,
+};
+module_i2c_driver(ts4900_gpio_driver);
+
+MODULE_AUTHOR("Technologic Systems");
+MODULE_DESCRIPTION("GPIO interface for Technologic Systems I2C-FPGA core");
+MODULE_LICENSE("GPL");