mfd: ezx-pcap: Remove unused pcap_adc_sync

pcap_adc_sync() was added in 2009 by commit 13a09f9 ("mfd: add PCAP
driver") but has remained unused; the async version is still used.

Remove it.

Signed-off-by: "Dr. David Alan Gilbert" <linux@treblig.org>
Link: https://lore.kernel.org/r/20250306011027.257021-1-linux@treblig.org
Signed-off-by: Lee Jones <lee@kernel.org>

Author: Dr. David Alan Gilbert

drivers/mfd/ezx-pcap.c

@@ -25,11 +25,6 @@ struct pcap_adc_request {
 	void *data;
 };
 
-struct pcap_adc_sync_request {
-	u16 res[2];
-	struct completion completion;
-};
-
 struct pcap_chip {
 	struct spi_device *spi;
 
@@ -335,34 +330,6 @@ int pcap_adc_async(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
 }
 EXPORT_SYMBOL_GPL(pcap_adc_async);
 
-static void pcap_adc_sync_cb(void *param, u16 res[])
-{
-	struct pcap_adc_sync_request *req = param;
-
-	req->res[0] = res[0];
-	req->res[1] = res[1];
-	complete(&req->completion);
-}
-
-int pcap_adc_sync(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
-								u16 res[])
-{
-	struct pcap_adc_sync_request sync_data;
-	int ret;
-
-	init_completion(&sync_data.completion);
-	ret = pcap_adc_async(pcap, bank, flags, ch, pcap_adc_sync_cb,
-								&sync_data);
-	if (ret)
-		return ret;
-	wait_for_completion(&sync_data.completion);
-	res[0] = sync_data.res[0];
-	res[1] = sync_data.res[1];
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(pcap_adc_sync);
-
 /* subdevs */
 static int pcap_remove_subdev(struct device *dev, void *unused)
 {

include/linux/mfd/ezx-pcap.h

@@ -31,7 +31,6 @@ int ezx_pcap_set_bits(struct pcap_chip *, u8, u32, u32);
 int pcap_to_irq(struct pcap_chip *, int);
 int irq_to_pcap(struct pcap_chip *, int);
 int pcap_adc_async(struct pcap_chip *, u8, u32, u8[], void *, void *);
-int pcap_adc_sync(struct pcap_chip *, u8, u32, u8[], u16[]);
 void pcap_set_ts_bits(struct pcap_chip *, u32);
 
 #define PCAP_SECOND_PORT	1