[PATCH 2/2] iio: magn: mmc5633: Add some ifdef / __maybe_unused until stubs available

[Jonathan Cameron <jic23@kernel.org>]

From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The I3C tree has Frank Li's fix for the case of I3C not being built
https://lore.kernel.org/all/20251230145718.4088694-1-Frank.Li@nxp.com/
Given those will only be available upstream at the next merge window
and the ordering of merge of I3C vs IIO is uncertain, apply some temporary
stubs in the driver to avoid build issues.

This can be reverted next cycle.

Fixes: 6e5f6bf2e3f0 ("iio: magnetometer: Add mmc5633 sensor")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202512280443.lOhY75Df-lkp@intel.com/
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/magnetometer/mmc5633.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/magnetometer/mmc5633.c b/drivers/iio/magnetometer/mmc5633.c
index 9d8e27486963..37f46fe5e9e4 100644
--- a/drivers/iio/magnetometer/mmc5633.c
+++ b/drivers/iio/magnetometer/mmc5633.c
@@ -190,32 +190,37 @@ static bool mmc5633_is_support_hdr(struct mmc5633_data *data)
 	if (!data->i3cdev)
 		return false;
 
+#ifdef CONFIG_I3C
 	return i3c_device_get_supported_xfer_mode(data->i3cdev) & BIT(I3C_HDR_DDR);
+#else
+	return false;
+#endif
 }
 
 static int mmc5633_read_measurement(struct mmc5633_data *data, int address, void *buf, size_t sz)
 {
 	struct device *dev = regmap_get_device(data->regmap);
 	u8 data_cmd[2], status[2];
-	unsigned int val, ready;
+	unsigned int val;
+	unsigned int ready __maybe_unused;
 	int ret;
 
 	if (mmc5633_is_support_hdr(data)) {
-		struct i3c_xfer xfers_wr_cmd[] = {
+		struct i3c_xfer xfers_wr_cmd[] __maybe_unused = {
 			{
 				.cmd = 0x3b,
 				.len = 2,
 				.data.out = data_cmd,
 			}
 		};
-		struct i3c_xfer xfers_rd_sta_cmd[] = {
+		struct i3c_xfer xfers_rd_sta_cmd[] __maybe_unused = {
 			{
 				.cmd = 0x23 | BIT(7), /* RDSTA CMD */
 				.len = 2,
 				.data.in = status,
 			},
 		};
-		struct i3c_xfer xfers_rd_data_cmd[] = {
+		struct i3c_xfer xfers_rd_data_cmd[] __maybe_unused = {
 			{
 				.cmd = 0x22 | BIT(7), /* RDLONG CMD */
 				.len = sz,
@@ -227,19 +232,27 @@ static int mmc5633_read_measurement(struct mmc5633_data *data, int address, void
 		data_cmd[1] = (address == MMC5633_TEMPERATURE) ?
 			      MMC5633_HDR_CTRL0_MEAS_T : MMC5633_HDR_CTRL0_MEAS_M;
 
+#ifdef CONFIG_I3C
 		ret = i3c_device_do_xfers(data->i3cdev, xfers_wr_cmd,
 					  ARRAY_SIZE(xfers_wr_cmd), I3C_HDR_DDR);
+#else
+		return -EOPNOTSUPP;
+#endif
 		if (ret < 0)
 			return ret;
 
 		ready = (address == MMC5633_TEMPERATURE) ?
 			MMC5633_STATUS1_MEAS_T_DONE_BIT : MMC5633_STATUS1_MEAS_M_DONE_BIT;
+#ifdef CONFIG_I3C
 		ret = read_poll_timeout(i3c_device_do_xfers, val,
 					val || (status[0] & ready),
 					10 * USEC_PER_MSEC,
 					100 * 10 * USEC_PER_MSEC, 0,
 					data->i3cdev, xfers_rd_sta_cmd,
 					ARRAY_SIZE(xfers_rd_sta_cmd), I3C_HDR_DDR);
+#else
+		ret = -EOPNOTSUPP;
+#endif
 		if (ret) {
 			dev_err(dev, "data not ready\n");
 			return ret;
@@ -248,8 +261,12 @@ static int mmc5633_read_measurement(struct mmc5633_data *data, int address, void
 			dev_err(dev, "i3c transfer error\n");
 			return val;
 		}
+#ifdef CONFIG_I3C
 		return i3c_device_do_xfers(data->i3cdev, xfers_rd_data_cmd,
 					   ARRAY_SIZE(xfers_rd_data_cmd), I3C_HDR_DDR);
+#else
+		return -EOPNOTSUPP;
+#endif
 	}
 
 	/* Fallback to use SDR/I2C mode */
-- 
2.52.0