[PATCH v2 09/15] 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

Put i2c_enable on the UART group. In modes 0 and 3 ft260_gpio_init()
runs from the UART probe, so that interface registers the gpiochip. A
write to i2c_enable updates dev->gpio_en of the interface that owns
the attribute. On the I2C interface the write would re-mux GPIO0 and
GPIO1 on the chip and leave the gpiochip's mask unchanged, so the two
lines would stay unavailable.

Do not expose i2c_reset on the UART group (reported by Sashiko).

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

---
v2: i2c_enable moves to the UART group, which owns the gpiochip; UART
group drops i2c_reset (reported by Sashiko).
---
 drivers/hid/hid-ft260.c | 60 ++++++++++++++++++++++++++++++++++-------
 1 file changed, 51 insertions(+), 9 deletions(-)

diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index 4106066b6a89..dca0250f2c25 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -1630,7 +1630,7 @@ 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,
@@ -1641,8 +1641,6 @@ 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,
@@ -1650,6 +1648,32 @@ 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);
 
@@ -2275,7 +2299,16 @@ 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_i2c_free;
+		}
+	} 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;
@@ -2341,12 +2374,14 @@ 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_hid_report;
@@ -2464,11 +2499,18 @@ static void ft260_remove(struct hid_device *hdev)
 					   dev->index);
 		ft260_uart_port_remove(dev);
 		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