--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+//
+// CS42L43 Pinctrl and GPIO driver
+//
+// Copyright (c) 2023 Cirrus Logic, Inc. and
+// Cirrus Logic International Semiconductor Ltd.
+
+#include <linux/bits.h>
+#include <linux/build_bug.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/gpio/driver.h>
+#include <linux/mfd/cs42l43.h>
+#include <linux/mfd/cs42l43-regs.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/string_helpers.h>
+
+#include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinmux.h>
+
+#include "../pinctrl-utils.h"
+
+#define CS42L43_NUM_GPIOS 3
+
+struct cs42l43_pin {
+ struct gpio_chip gpio_chip;
+
+ struct device *dev;
+ struct regmap *regmap;
+ bool shutters_locked;
+};
+
+struct cs42l43_pin_data {
+ unsigned int reg;
+ unsigned int shift;
+ unsigned int mask;
+};
+
+#define CS42L43_PIN(_number, _name, _reg, _field) { \
+ .number = _number, .name = _name, \
+ .drv_data = &((struct cs42l43_pin_data){ \
+ .reg = CS42L43_##_reg, \
+ .shift = CS42L43_##_field##_DRV_SHIFT, \
+ .mask = CS42L43_##_field##_DRV_MASK, \
+ }), \
+}
+
+static const struct pinctrl_pin_desc cs42l43_pin_pins[] = {
+ CS42L43_PIN(0, "gpio1", DRV_CTRL4, GPIO1),
+ CS42L43_PIN(1, "gpio2", DRV_CTRL4, GPIO2),
+ CS42L43_PIN(2, "gpio3", DRV_CTRL4, GPIO3),
+ CS42L43_PIN(3, "asp_dout", DRV_CTRL1, ASP_DOUT),
+ CS42L43_PIN(4, "asp_fsync", DRV_CTRL1, ASP_FSYNC),
+ CS42L43_PIN(5, "asp_bclk", DRV_CTRL1, ASP_BCLK),
+ CS42L43_PIN(6, "pdmout2_clk", DRV_CTRL3, PDMOUT2_CLK),
+ CS42L43_PIN(7, "pdmout2_data", DRV_CTRL3, PDMOUT2_DATA),
+ CS42L43_PIN(8, "pdmout1_clk", DRV_CTRL3, PDMOUT1_CLK),
+ CS42L43_PIN(9, "pdmout1_data", DRV_CTRL3, PDMOUT1_DATA),
+ CS42L43_PIN(10, "i2c_sda", DRV_CTRL3, I2C_SDA),
+ CS42L43_PIN(11, "i2c_scl", DRV_CTRL_5, I2C_SCL),
+ CS42L43_PIN(12, "spi_miso", DRV_CTRL3, SPI_MISO),
+ CS42L43_PIN(13, "spi_sck", DRV_CTRL_5, SPI_SCK),
+ CS42L43_PIN(14, "spi_ssb", DRV_CTRL_5, SPI_SSB),
+};
+
+static const unsigned int cs42l43_pin_gpio1_pins[] = { 0 };
+static const unsigned int cs42l43_pin_gpio2_pins[] = { 1 };
+static const unsigned int cs42l43_pin_gpio3_pins[] = { 2 };
+static const unsigned int cs42l43_pin_asp_pins[] = { 3, 4, 5 };
+static const unsigned int cs42l43_pin_pdmout2_pins[] = { 6, 7 };
+static const unsigned int cs42l43_pin_pdmout1_pins[] = { 8, 9 };
+static const unsigned int cs42l43_pin_i2c_pins[] = { 10, 11 };
+static const unsigned int cs42l43_pin_spi_pins[] = { 12, 13, 14 };
+
+#define CS42L43_PINGROUP(_name) \
+ PINCTRL_PINGROUP(#_name, cs42l43_pin_##_name##_pins, \
+ ARRAY_SIZE(cs42l43_pin_##_name##_pins))
+
+static const struct pingroup cs42l43_pin_groups[] = {
+ CS42L43_PINGROUP(gpio1),
+ CS42L43_PINGROUP(gpio2),
+ CS42L43_PINGROUP(gpio3),
+ CS42L43_PINGROUP(asp),
+ CS42L43_PINGROUP(pdmout2),
+ CS42L43_PINGROUP(pdmout1),
+ CS42L43_PINGROUP(i2c),
+ CS42L43_PINGROUP(spi),
+};
+
+static int cs42l43_pin_get_groups_count(struct pinctrl_dev *pctldev)
+{
+ return ARRAY_SIZE(cs42l43_pin_groups);
+}
+
+static const char *cs42l43_pin_get_group_name(struct pinctrl_dev *pctldev,
+ unsigned int group_idx)
+{
+ return cs42l43_pin_groups[group_idx].name;
+}
+
+static int cs42l43_pin_get_group_pins(struct pinctrl_dev *pctldev,
+ unsigned int group_idx,
+ const unsigned int **pins,
+ unsigned int *num_pins)
+{
+ *pins = cs42l43_pin_groups[group_idx].pins;
+ *num_pins = cs42l43_pin_groups[group_idx].npins;
+
+ return 0;
+}
+
+static const struct pinctrl_ops cs42l43_pin_group_ops = {
+ .get_groups_count = cs42l43_pin_get_groups_count,
+ .get_group_name = cs42l43_pin_get_group_name,
+ .get_group_pins = cs42l43_pin_get_group_pins,
+#if IS_ENABLED(CONFIG_OF)
+ .dt_node_to_map = pinconf_generic_dt_node_to_map_all,
+ .dt_free_map = pinconf_generic_dt_free_map,
+#endif
+};
+
+enum cs42l43_pin_funcs {
+ CS42L43_FUNC_GPIO,
+ CS42L43_FUNC_SPDIF,
+ CS42L43_FUNC_IRQ,
+ CS42L43_FUNC_MIC_SHT,
+ CS42L43_FUNC_SPK_SHT,
+ CS42L43_FUNC_MAX
+};
+
+static const char * const cs42l43_pin_funcs[] = {
+ "gpio", "spdif", "irq", "mic-shutter", "spk-shutter",
+};
+
+static const char * const cs42l43_pin_gpio_groups[] = { "gpio1", "gpio3" };
+static const char * const cs42l43_pin_spdif_groups[] = { "gpio3" };
+static const char * const cs42l43_pin_irq_groups[] = { "gpio1" };
+static const char * const cs42l43_pin_shutter_groups[] = { "gpio1", "gpio2", "gpio3" };
+
+static const struct pinfunction cs42l43_pin_func_groups[] = {
+ PINCTRL_PINFUNCTION("gpio", cs42l43_pin_gpio_groups,
+ ARRAY_SIZE(cs42l43_pin_gpio_groups)),
+ PINCTRL_PINFUNCTION("spdif", cs42l43_pin_spdif_groups,
+ ARRAY_SIZE(cs42l43_pin_spdif_groups)),
+ PINCTRL_PINFUNCTION("irq", cs42l43_pin_irq_groups,
+ ARRAY_SIZE(cs42l43_pin_irq_groups)),
+ PINCTRL_PINFUNCTION("mic-shutter", cs42l43_pin_shutter_groups,
+ ARRAY_SIZE(cs42l43_pin_shutter_groups)),
+ PINCTRL_PINFUNCTION("spk-shutter", cs42l43_pin_shutter_groups,
+ ARRAY_SIZE(cs42l43_pin_shutter_groups)),
+};
+
+static_assert(ARRAY_SIZE(cs42l43_pin_funcs) == CS42L43_FUNC_MAX);
+static_assert(ARRAY_SIZE(cs42l43_pin_func_groups) == CS42L43_FUNC_MAX);
+
+static int cs42l43_pin_get_func_count(struct pinctrl_dev *pctldev)
+{
+ return ARRAY_SIZE(cs42l43_pin_funcs);
+}
+
+static const char *cs42l43_pin_get_func_name(struct pinctrl_dev *pctldev,
+ unsigned int func_idx)
+{
+ return cs42l43_pin_funcs[func_idx];
+}
+
+static int cs42l43_pin_get_func_groups(struct pinctrl_dev *pctldev,
+ unsigned int func_idx,
+ const char * const **groups,
+ unsigned int * const num_groups)
+{
+ *groups = cs42l43_pin_func_groups[func_idx].groups;
+ *num_groups = cs42l43_pin_func_groups[func_idx].ngroups;
+
+ return 0;
+}
+
+static int cs42l43_pin_set_mux(struct pinctrl_dev *pctldev,
+ unsigned int func_idx, unsigned int group_idx)
+{
+ struct cs42l43_pin *priv = pinctrl_dev_get_drvdata(pctldev);
+ unsigned int reg, mask, val;
+
+ dev_dbg(priv->dev, "Setting %s to %s\n",
+ cs42l43_pin_groups[group_idx].name, cs42l43_pin_funcs[func_idx]);
+
+ switch (func_idx) {
+ case CS42L43_FUNC_MIC_SHT:
+ reg = CS42L43_SHUTTER_CONTROL;
+ mask = CS42L43_MIC_SHUTTER_CFG_MASK;
+ val = 0x2 << (group_idx + CS42L43_MIC_SHUTTER_CFG_SHIFT);
+ break;
+ case CS42L43_FUNC_SPK_SHT:
+ reg = CS42L43_SHUTTER_CONTROL;
+ mask = CS42L43_SPK_SHUTTER_CFG_MASK;
+ val = 0x2 << (group_idx + CS42L43_SPK_SHUTTER_CFG_SHIFT);
+ break;
+ default:
+ reg = CS42L43_GPIO_FN_SEL;
+ mask = BIT(group_idx + CS42L43_GPIO1_FN_SEL_SHIFT);
+ val = (func_idx == CS42L43_FUNC_GPIO) ?
+ (0x1 << (group_idx + CS42L43_GPIO1_FN_SEL_SHIFT)) : 0;
+ break;
+ }
+
+ if (priv->shutters_locked && reg == CS42L43_SHUTTER_CONTROL) {
+ dev_err(priv->dev, "Shutter configuration not available\n");
+ return -EPERM;
+ }
+
+ return regmap_update_bits(priv->regmap, reg, mask, val);
+}
+
+static int cs42l43_gpio_set_direction(struct pinctrl_dev *pctldev,
+ struct pinctrl_gpio_range *range,
+ unsigned int offset, bool input)
+{
+ struct cs42l43_pin *priv = pinctrl_dev_get_drvdata(pctldev);
+ unsigned int shift = offset + CS42L43_GPIO1_DIR_SHIFT;
+ int ret;
+
+ dev_dbg(priv->dev, "Setting gpio%d to %s\n",
+ offset + 1, input ? "input" : "output");
+
+ ret = pm_runtime_resume_and_get(priv->dev);
+ if (ret) {
+ dev_err(priv->dev, "Failed to resume for direction: %d\n", ret);
+ return ret;
+ }
+
+ ret = regmap_update_bits(priv->regmap, CS42L43_GPIO_CTRL1,
+ BIT(shift), !!input << shift);
+ if (ret)
+ dev_err(priv->dev, "Failed to set gpio%d direction: %d\n",
+ offset + 1, ret);
+
+ pm_runtime_put(priv->dev);
+
+ return ret;
+}
+
+static int cs42l43_gpio_request_enable(struct pinctrl_dev *pctldev,
+ struct pinctrl_gpio_range *range,
+ unsigned int offset)
+{
+ return cs42l43_pin_set_mux(pctldev, 0, offset);
+}
+
+static void cs42l43_gpio_disable_free(struct pinctrl_dev *pctldev,
+ struct pinctrl_gpio_range *range,
+ unsigned int offset)
+{
+ cs42l43_gpio_set_direction(pctldev, range, offset, true);
+}
+
+static const struct pinmux_ops cs42l43_pin_mux_ops = {
+ .get_functions_count = cs42l43_pin_get_func_count,
+ .get_function_name = cs42l43_pin_get_func_name,
+ .get_function_groups = cs42l43_pin_get_func_groups,
+
+ .set_mux = cs42l43_pin_set_mux,
+
+ .gpio_request_enable = cs42l43_gpio_request_enable,
+ .gpio_disable_free = cs42l43_gpio_disable_free,
+ .gpio_set_direction = cs42l43_gpio_set_direction,
+
+ .strict = true,
+};
+
+static const unsigned int cs42l43_pin_drv_str_ma[] = { 1, 2, 4, 8, 9, 10, 12, 16 };
+
+static inline int cs42l43_pin_get_drv_str(struct cs42l43_pin *priv, unsigned int pin)
+{
+ const struct cs42l43_pin_data *pdat = cs42l43_pin_pins[pin].drv_data;
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(priv->regmap, pdat->reg, &val);
+ if (ret)
+ return ret;
+
+ return cs42l43_pin_drv_str_ma[(val & pdat->mask) >> pdat->shift];
+}
+
+static inline int cs42l43_pin_set_drv_str(struct cs42l43_pin *priv, unsigned int pin,
+ unsigned int ma)
+{
+ const struct cs42l43_pin_data *pdat = cs42l43_pin_pins[pin].drv_data;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(cs42l43_pin_drv_str_ma); i++) {
+ if (ma == cs42l43_pin_drv_str_ma[i]) {
+ if ((i << pdat->shift) > pdat->mask)
+ goto err;
+
+ dev_dbg(priv->dev, "Set drive strength for %s to %d mA\n",
+ cs42l43_pin_pins[pin].name, ma);
+
+ return regmap_update_bits(priv->regmap, pdat->reg,
+ pdat->mask, i << pdat->shift);
+ }
+ }
+
+err:
+ dev_err(priv->dev, "Invalid drive strength for %s: %d mA\n",
+ cs42l43_pin_pins[pin].name, ma);
+ return -EINVAL;
+}
+
+static inline int cs42l43_pin_get_db(struct cs42l43_pin *priv, unsigned int pin)
+{
+ unsigned int val;
+ int ret;
+
+ if (pin >= CS42L43_NUM_GPIOS)
+ return -ENOTSUPP;
+
+ ret = regmap_read(priv->regmap, CS42L43_GPIO_CTRL2, &val);
+ if (ret)
+ return ret;
+
+ if (val & (CS42L43_GPIO1_DEGLITCH_BYP_MASK << pin))
+ return 0;
+
+ return 85; // Debounce is roughly 85uS
+}
+
+static inline int cs42l43_pin_set_db(struct cs42l43_pin *priv, unsigned int pin,
+ unsigned int us)
+{
+ if (pin >= CS42L43_NUM_GPIOS)
+ return -ENOTSUPP;
+
+ dev_dbg(priv->dev, "Set debounce %s for %s\n",
+ str_on_off(us), cs42l43_pin_pins[pin].name);
+
+ return regmap_update_bits(priv->regmap, CS42L43_GPIO_CTRL2,
+ CS42L43_GPIO1_DEGLITCH_BYP_MASK << pin,
+ !!us << pin);
+}
+
+static int cs42l43_pin_config_get(struct pinctrl_dev *pctldev,
+ unsigned int pin, unsigned long *config)
+{
+ struct cs42l43_pin *priv = pinctrl_dev_get_drvdata(pctldev);
+ unsigned int param = pinconf_to_config_param(*config);
+ int ret;
+
+ switch (param) {
+ case PIN_CONFIG_DRIVE_STRENGTH:
+ ret = cs42l43_pin_get_drv_str(priv, pin);
+ if (ret < 0)
+ return ret;
+ break;
+ case PIN_CONFIG_INPUT_DEBOUNCE:
+ ret = cs42l43_pin_get_db(priv, pin);
+ if (ret < 0)
+ return ret;
+ break;
+ default:
+ return -ENOTSUPP;
+ }
+
+ *config = pinconf_to_config_packed(param, ret);
+
+ return 0;
+}
+
+static int cs42l43_pin_config_set(struct pinctrl_dev *pctldev, unsigned int pin,
+ unsigned long *configs, unsigned int num_configs)
+{
+ struct cs42l43_pin *priv = pinctrl_dev_get_drvdata(pctldev);
+ unsigned int val;
+ int ret;
+
+ while (num_configs) {
+ val = pinconf_to_config_argument(*configs);
+
+ switch (pinconf_to_config_param(*configs)) {
+ case PIN_CONFIG_DRIVE_STRENGTH:
+ ret = cs42l43_pin_set_drv_str(priv, pin, val);
+ if (ret)
+ return ret;
+ break;
+ case PIN_CONFIG_INPUT_DEBOUNCE:
+ ret = cs42l43_pin_set_db(priv, pin, val);
+ if (ret)
+ return ret;
+ break;
+ default:
+ return -ENOTSUPP;
+ }
+
+ configs++;
+ num_configs--;
+ }
+
+ return 0;
+}
+
+static int cs42l43_pin_config_group_get(struct pinctrl_dev *pctldev,
+ unsigned int selector, unsigned long *config)
+{
+ int i, ret;
+
+ for (i = 0; i < cs42l43_pin_groups[selector].npins; ++i) {
+ ret = cs42l43_pin_config_get(pctldev,
+ cs42l43_pin_groups[selector].pins[i],
+ config);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int cs42l43_pin_config_group_set(struct pinctrl_dev *pctldev,
+ unsigned int selector,
+ unsigned long *configs,
+ unsigned int num_configs)
+{
+ int i, ret;
+
+ for (i = 0; i < cs42l43_pin_groups[selector].npins; ++i) {
+ ret = cs42l43_pin_config_set(pctldev,
+ cs42l43_pin_groups[selector].pins[i],
+ configs, num_configs);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct pinconf_ops cs42l43_pin_conf_ops = {
+ .is_generic = true,
+
+ .pin_config_get = cs42l43_pin_config_get,
+ .pin_config_set = cs42l43_pin_config_set,
+ .pin_config_group_get = cs42l43_pin_config_group_get,
+ .pin_config_group_set = cs42l43_pin_config_group_set,
+};
+
+static struct pinctrl_desc cs42l43_pin_desc = {
+ .name = "cs42l43-pinctrl",
+ .owner = THIS_MODULE,
+
+ .pins = cs42l43_pin_pins,
+ .npins = ARRAY_SIZE(cs42l43_pin_pins),
+
+ .pctlops = &cs42l43_pin_group_ops,
+ .pmxops = &cs42l43_pin_mux_ops,
+ .confops = &cs42l43_pin_conf_ops,
+};
+
+static int cs42l43_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct cs42l43_pin *priv = gpiochip_get_data(chip);
+ unsigned int val;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(priv->dev);
+ if (ret) {
+ dev_err(priv->dev, "Failed to resume for get: %d\n", ret);
+ return ret;
+ }
+
+ ret = regmap_read(priv->regmap, CS42L43_GPIO_STS, &val);
+ if (ret)
+ dev_err(priv->dev, "Failed to get gpio%d: %d\n", offset + 1, ret);
+ else
+ ret = !!(val & BIT(offset + CS42L43_GPIO1_STS_SHIFT));
+
+ pm_runtime_put(priv->dev);
+
+ return ret;
+}
+
+static void cs42l43_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
+{
+ struct cs42l43_pin *priv = gpiochip_get_data(chip);
+ unsigned int shift = offset + CS42L43_GPIO1_LVL_SHIFT;
+ int ret;
+
+ dev_dbg(priv->dev, "Setting gpio%d to %s\n",
+ offset + 1, value ? "high" : "low");
+
+ ret = pm_runtime_resume_and_get(priv->dev);
+ if (ret) {
+ dev_err(priv->dev, "Failed to resume for set: %d\n", ret);
+ return;
+ }
+
+ ret = regmap_update_bits(priv->regmap, CS42L43_GPIO_CTRL1,
+ BIT(shift), value << shift);
+ if (ret)
+ dev_err(priv->dev, "Failed to set gpio%d: %d\n", offset + 1, ret);
+
+ pm_runtime_put(priv->dev);
+}
+
+static int cs42l43_gpio_direction_in(struct gpio_chip *chip, unsigned int offset)
+{
+ return pinctrl_gpio_direction_input(chip->base + offset);
+}
+
+static int cs42l43_gpio_direction_out(struct gpio_chip *chip,
+ unsigned int offset, int value)
+{
+ cs42l43_gpio_set(chip, offset, value);
+
+ return pinctrl_gpio_direction_output(chip->base + offset);
+}
+
+static int cs42l43_gpio_add_pin_ranges(struct gpio_chip *chip)
+{
+ struct cs42l43_pin *priv = gpiochip_get_data(chip);
+ int ret;
+
+ ret = gpiochip_add_pin_range(&priv->gpio_chip, priv->gpio_chip.label,
+ 0, 0, CS42L43_NUM_GPIOS);
+ if (ret)
+ dev_err(priv->dev, "Failed to add GPIO pin range: %d\n", ret);
+
+ return ret;
+}
+
+static int cs42l43_pin_probe(struct platform_device *pdev)
+{
+ struct cs42l43 *cs42l43 = dev_get_drvdata(pdev->dev.parent);
+ struct cs42l43_pin *priv;
+ struct pinctrl_dev *pctldev;
+ struct fwnode_handle *fwnode = dev_fwnode(cs42l43->dev);
+ int ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = &pdev->dev;
+ priv->regmap = cs42l43->regmap;
+
+ priv->shutters_locked = cs42l43->hw_lock;
+
+ priv->gpio_chip.request = gpiochip_generic_request;
+ priv->gpio_chip.free = gpiochip_generic_free;
+ priv->gpio_chip.direction_input = cs42l43_gpio_direction_in;
+ priv->gpio_chip.direction_output = cs42l43_gpio_direction_out;
+ priv->gpio_chip.add_pin_ranges = cs42l43_gpio_add_pin_ranges;
+ priv->gpio_chip.get = cs42l43_gpio_get;
+ priv->gpio_chip.set = cs42l43_gpio_set;
+ priv->gpio_chip.label = dev_name(priv->dev);
+ priv->gpio_chip.parent = priv->dev;
+ priv->gpio_chip.can_sleep = true;
+ priv->gpio_chip.base = -1;
+ priv->gpio_chip.ngpio = CS42L43_NUM_GPIOS;
+
+ if (is_of_node(fwnode)) {
+ fwnode = fwnode_get_named_child_node(fwnode, "pinctrl");
+
+ if (fwnode && !fwnode->dev)
+ fwnode->dev = priv->dev;
+ }
+
+ priv->gpio_chip.fwnode = fwnode;
+
+ device_set_node(priv->dev, fwnode);
+
+ devm_pm_runtime_enable(priv->dev);
+ pm_runtime_idle(priv->dev);
+
+ pctldev = devm_pinctrl_register(priv->dev, &cs42l43_pin_desc, priv);
+ if (IS_ERR(pctldev))
+ return dev_err_probe(priv->dev, PTR_ERR(pctldev),
+ "Failed to register pinctrl\n");
+
+ ret = devm_gpiochip_add_data(priv->dev, &priv->gpio_chip, priv);
+ if (ret)
+ return dev_err_probe(priv->dev, ret,
+ "Failed to register gpiochip\n");
+
+ return 0;
+}
+
+static const struct platform_device_id cs42l43_pin_id_table[] = {
+ { "cs42l43-pinctrl", },
+ {}
+};
+MODULE_DEVICE_TABLE(platform, cs42l43_pin_id_table);
+
+static struct platform_driver cs42l43_pin_driver = {
+ .driver = {
+ .name = "cs42l43-pinctrl",
+ },
+ .probe = cs42l43_pin_probe,
+ .id_table = cs42l43_pin_id_table,
+};
+module_platform_driver(cs42l43_pin_driver);
+
+MODULE_DESCRIPTION("CS42L43 Pinctrl Driver");
+MODULE_AUTHOR("Charles Keepax <ckeepax@opensource.cirrus.com>");
+MODULE_LICENSE("GPL");
projects / linux-2.6-block.git / commitdiff