[PATCH v3 09/16] HID: ft260: group sysfs attrs per HID interface

[Michael Zaidman <michael.zaidman@gmail.com>]

Split the single sysfs attribute group into per-interface groups based
on chip mode (DCNF0/DCNF1):

- I2C-only (mode 1): I2C and GPIO attributes on the I2C HID interface
- Dual mode (0/3): hid_over_i2c_en, i2c_reset and clock on the I2C
  interface; GPIO and UART attrs on the UART interface
- UART-only (mode 2): GPIO and UART attrs on the UART interface

i2c_enable is GPIO-related too: it switches GPIO0 and GPIO1 between I2C
and GPIO, and its store updates gpio_en of its own interface. So it is
on the interface with the gpiochip, the UART interface in modes 0 and 3.

i2c_reset is an I2C attribute, so it is only on the I2C interface and
not in the UART group, which holds the GPIO and UART attributes.

Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>

---
v2:
Fixes for the issues reported by Sashiko:
- The i2c_enable attribute was missing in modes 0 and 3; it is now in
  the UART group, with the gpiochip.
- The i2c_reset attribute, an I2C attribute, is no longer in the UART
  group.

v3:
The err_register_tty path, which patch 3 adds to ft260_uart_probe(),
removes the UART attribute group of this patch.
---
 drivers/hid/hid-ft260.c | 63 ++++++++++++++++++++++++++++++++++-------
 1 file changed, 53 insertions(+), 10 deletions(-)

diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index d795355fc26b..b68cb0748a23 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -1633,7 +1633,7 @@ static ssize_t i2c_reset_store(struct device *kdev,
 }
 static DEVICE_ATTR_WO(i2c_reset);
 
-static const struct attribute_group ft260_attr_group = {
+static const struct attribute_group ft260_i2c_chip_mode_1_attr_group = {
 	.attrs = (struct attribute *[]) {
 		  &dev_attr_chip_mode.attr,
 		  &dev_attr_pwren_status.attr,
@@ -1644,8 +1644,6 @@ static const struct attribute_group ft260_attr_group = {
 		  &dev_attr_gpio2_func.attr,
 		  &dev_attr_gpioa_func.attr,
 		  &dev_attr_gpiog_func.attr,
-		  &dev_attr_uart_mode.attr,
-		  &dev_attr_uart_dcd_ri.attr,
 		  &dev_attr_clock_ctl.attr,
 		  &dev_attr_i2c_reset.attr,
 		  &dev_attr_clock.attr,
@@ -1653,6 +1651,32 @@ static const struct attribute_group ft260_attr_group = {
 	}
 };
 
+static const struct attribute_group ft260_i2c_chip_mode_0_3_attr_group = {
+	.attrs = (struct attribute *[]) {
+		  &dev_attr_hid_over_i2c_en.attr,
+		  &dev_attr_i2c_reset.attr,
+		  &dev_attr_clock.attr,
+		  NULL
+	}
+};
+
+static const struct attribute_group ft260_uart_chip_mode_0_2_3_attr_group = {
+	.attrs = (struct attribute *[]) {
+		  &dev_attr_chip_mode.attr,
+		  &dev_attr_pwren_status.attr,
+		  &dev_attr_suspend_status.attr,
+		  &dev_attr_power_saving_en.attr,
+		  &dev_attr_i2c_enable.attr,
+		  &dev_attr_gpio2_func.attr,
+		  &dev_attr_gpioa_func.attr,
+		  &dev_attr_gpiog_func.attr,
+		  &dev_attr_uart_mode.attr,
+		  &dev_attr_uart_dcd_ri.attr,
+		  &dev_attr_clock_ctl.attr,
+		  NULL
+	}
+};
+
 static DEFINE_MUTEX(ft260_uart_list_lock);
 static LIST_HEAD(ft260_uart_device_list);
 
@@ -2297,11 +2321,20 @@ static int ft260_i2c_probe(struct ft260_device *dev,
 		if (ret)
 			goto err_i2c_free;
 
-		ret = sysfs_create_group(&hdev->dev.kobj, &ft260_attr_group);
+		ret = sysfs_create_group(&hdev->dev.kobj,
+					 &ft260_i2c_chip_mode_1_attr_group);
 		if (ret < 0) {
 			hid_err(hdev, "failed to create sysfs attrs\n");
 			goto err_gpio_remove;
 		}
+	} else if (cfg->chip_mode == FT260_MODE_ALL ||
+		   cfg->chip_mode == FT260_MODE_BOTH) {
+		ret = sysfs_create_group(&hdev->dev.kobj,
+					 &ft260_i2c_chip_mode_0_3_attr_group);
+		if (ret < 0) {
+			hid_err(hdev, "failed to create sysfs attrs\n");
+			goto err_i2c_free;
+		}
 	}
 
 	return 0;
@@ -2355,12 +2388,14 @@ static int ft260_uart_probe(struct ft260_device *dev,
 	cfg->uart_mode = FT260_UART_CFG_FLOW_CTRL_NONE;
 
 	if (dev->chip_mode & FT260_MODE_UART ||
-	    dev->chip_mode == FT260_MODE_ALL) {
+	    dev->chip_mode == FT260_MODE_ALL ||
+	    dev->chip_mode == FT260_MODE_BOTH) {
 		ret = ft260_gpio_init(dev, cfg);
 		if (ret)
 			goto err_hid_report;
 
-		ret = sysfs_create_group(&hdev->dev.kobj, &ft260_attr_group);
+		ret = sysfs_create_group(&hdev->dev.kobj,
+					 &ft260_uart_chip_mode_0_2_3_attr_group);
 		if (ret < 0) {
 			hid_err(hdev, "failed to create sysfs attrs\n");
 			goto err_gpio_remove;
@@ -2383,7 +2418,8 @@ static int ft260_uart_probe(struct ft260_device *dev,
 
 err_register_tty:
 	if (dev->gc.parent)
-		sysfs_remove_group(&hdev->dev.kobj, &ft260_attr_group);
+		sysfs_remove_group(&hdev->dev.kobj,
+				   &ft260_uart_chip_mode_0_2_3_attr_group);
 err_gpio_remove:
 	if (dev->gc.parent)
 		gpiochip_remove(&dev->gc);
@@ -2499,11 +2535,18 @@ static void ft260_remove(struct hid_device *hdev)
 		dev->removed = true;
 		mutex_unlock(&dev->lock);
 		if (dev->chip_mode & FT260_MODE_UART ||
-		    dev->chip_mode == FT260_MODE_ALL)
-			sysfs_remove_group(&hdev->dev.kobj, &ft260_attr_group);
+		    dev->chip_mode == FT260_MODE_ALL ||
+		    dev->chip_mode == FT260_MODE_BOTH)
+			sysfs_remove_group(&hdev->dev.kobj,
+					   &ft260_uart_chip_mode_0_2_3_attr_group);
 	} else {
 		if (dev->chip_mode == FT260_MODE_I2C)
-			sysfs_remove_group(&hdev->dev.kobj, &ft260_attr_group);
+			sysfs_remove_group(&hdev->dev.kobj,
+					   &ft260_i2c_chip_mode_1_attr_group);
+		else if (dev->chip_mode == FT260_MODE_ALL ||
+			 dev->chip_mode == FT260_MODE_BOTH)
+			sysfs_remove_group(&hdev->dev.kobj,
+					   &ft260_i2c_chip_mode_0_3_attr_group);
 		i2c_del_adapter(&dev->adap);
 	}
 
-- 
2.43.0