IS31FL3737 Global Current Setting (#17420)

docs/feature_rgb_matrix.md

@@ -172,6 +172,7 @@ Configure the hardware via your `config.h`:
 | `ISSI_TIMEOUT` | (Optional) How long to wait for i2c messages, in milliseconds | 100 |
 | `ISSI_PERSISTENCE` | (Optional) Retry failed messages this many times | 0 |
 | `ISSI_PWM_FREQUENCY` | (Optional) PWM Frequency Setting - IS31FL3737B only | 0 |
+| `ISSI_GLOBALCURRENT` | (Optional) Configuration for the Global Current Register | 0xFF |
 | `ISSI_SWPULLUP` | (Optional) Set the value of the SWx lines on-chip de-ghosting resistors | PUR_0R (Disabled) |
 | `ISSI_CSPULLUP` | (Optional) Set the value of the CSx lines on-chip de-ghosting resistors | PUR_0R (Disabled) |
 | `DRIVER_COUNT` | (Required) How many RGB driver IC's are present | |

drivers/led/issi/is31fl3737.c

@@ -69,6 +69,10 @@
 #    define ISSI_CSPULLUP PUR_0R
 #endif
 
+#ifndef ISSI_GLOBALCURRENT
+#    define ISSI_GLOBALCURRENT 0xFF
+#endif
+
 // Transfer buffer for TWITransmitData()
 uint8_t g_twi_transfer_buffer[20];
 
@@ -161,7 +165,7 @@ void IS31FL3737_init(uint8_t addr) {
     // Set de-ghost pull-down resistors (CSx)
     IS31FL3737_write_register(addr, ISSI_REG_CSPULLUP, ISSI_CSPULLUP);
     // Set global current to maximum.
-    IS31FL3737_write_register(addr, ISSI_REG_GLOBALCURRENT, 0xFF);
+    IS31FL3737_write_register(addr, ISSI_REG_GLOBALCURRENT, ISSI_GLOBALCURRENT);
     // Disable software shutdown.
     IS31FL3737_write_register(addr, ISSI_REG_CONFIGURATION, ((ISSI_PWM_FREQUENCY & 0b111) << 3) | 0x01);