hwmon: (mr75203) enable polling for all VM channels

Configure ip-polling register to enable polling for all voltage monitor
channels.
This enables reading the voltage values for all inputs other than just
input 0.

Fixes: 9d82335 ("hwmon: Add hardware monitoring driver for Moortec MR75203 PVT controller")
Signed-off-by: Eliav Farber <farbere@amazon.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220908152449.35457-7-farbere@amazon.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Author: Eliav Farber

drivers/hwmon/mr75203.c

@@ -388,6 +388,19 @@ static int pvt_init(struct pvt_device *pvt)
 		if (ret)
 			return ret;
 
+		val = (BIT(pvt->c_num) - 1) | VM_CH_INIT |
+		      IP_POLL << SDIF_ADDR_SFT | SDIF_WRN_W | SDIF_PROG;
+		ret = regmap_write(v_map, SDIF_W, val);
+		if (ret < 0)
+			return ret;
+
+		ret = regmap_read_poll_timeout(v_map, SDIF_STAT,
+					       val, !(val & SDIF_BUSY),
+					       PVT_POLL_DELAY_US,
+					       PVT_POLL_TIMEOUT_US);
+		if (ret)
+			return ret;
+
 		val = CFG1_VOL_MEAS_MODE | CFG1_PARALLEL_OUT |
 		      CFG1_14_BIT | IP_CFG << SDIF_ADDR_SFT |
 		      SDIF_WRN_W | SDIF_PROG;