[BUG] Allow multiple IS31FL3741 drivers per board in rgb_matrix (#20988)

drivers/led/issi/is31fl3741.c

@@ -104,11 +104,11 @@ void IS31FL3741_write_register(uint8_t addr, uint8_t reg, uint8_t data) {
 }
 
 bool IS31FL3741_write_pwm_buffer(uint8_t addr, uint8_t *pwm_buffer) {
-    // Assume PG1 is already selected
+    // Assume PG0 is already selected
 
     for (int i = 0; i < 342; i += 18) {
         if (i == 180) {
-            // unlock the command register and select PG2
+            // unlock the command register and select PG1
             IS31FL3741_write_register(addr, ISSI_COMMANDREGISTER_WRITELOCK, 0xC5);
             IS31FL3741_write_register(addr, ISSI_COMMANDREGISTER, ISSI_PAGE_PWM1);
         }
@@ -246,7 +246,7 @@ void IS31FL3741_update_led_control_registers(uint8_t addr, uint8_t index) {
 
         // CS1_SW1 to CS30_SW6 are on PG2
         for (int i = CS1_SW1; i <= CS30_SW6; ++i) {
-            IS31FL3741_write_register(addr, i, g_scaling_registers[0][i]);
+            IS31FL3741_write_register(addr, i, g_scaling_registers[index][i]);
         }
 
         // unlock the command register and select PG3
@@ -255,7 +255,7 @@ void IS31FL3741_update_led_control_registers(uint8_t addr, uint8_t index) {
 
         // CS1_SW7 to CS39_SW9 are on PG3
         for (int i = CS1_SW7; i <= CS39_SW9; ++i) {
-            IS31FL3741_write_register(addr, i - CS1_SW7, g_scaling_registers[0][i]);
+            IS31FL3741_write_register(addr, i - CS1_SW7, g_scaling_registers[index][i]);
         }
 
         g_scaling_registers_update_required[index] = false;

quantum/rgb_matrix/rgb_matrix_drivers.c

@@ -98,6 +98,15 @@ static void init(void) {
 
 #    elif defined(IS31FL3741)
     IS31FL3741_init(DRIVER_ADDR_1);
+#        if defined(DRIVER_ADDR_2)
+    IS31FL3741_init(DRIVER_ADDR_2);
+#            if defined(DRIVER_ADDR_3)
+    IS31FL3741_init(DRIVER_ADDR_3);
+#                if defined(DRIVER_ADDR_4)
+    IS31FL3741_init(DRIVER_ADDR_4);
+#                endif
+#            endif
+#        endif
 
 #    elif defined(IS31FLCOMMON)
     IS31FL_common_init(DRIVER_ADDR_1, ISSI_SSR_1);
@@ -196,6 +205,15 @@ static void init(void) {
 
 #    elif defined(IS31FL3741)
     IS31FL3741_update_led_control_registers(DRIVER_ADDR_1, 0);
+#        if defined(DRIVER_ADDR_2)
+    IS31FL3741_update_led_control_registers(DRIVER_ADDR_2, 1);
+#            if defined(DRIVER_ADDR_3)
+    IS31FL3741_update_led_control_registers(DRIVER_ADDR_3, 2);
+#                if defined(DRIVER_ADDR_4)
+    IS31FL3741_update_led_control_registers(DRIVER_ADDR_4, 3);
+#                endif
+#            endif
+#        endif
 
 #    elif defined(IS31FLCOMMON)
 #        ifdef ISSI_MANUAL_SCALING
@@ -315,6 +333,12 @@ static void flush(void) {
     IS31FL3741_update_pwm_buffers(DRIVER_ADDR_1, 0);
 #        if defined(DRIVER_ADDR_2)
     IS31FL3741_update_pwm_buffers(DRIVER_ADDR_2, 1);
+#            if defined(DRIVER_ADDR_3)
+    IS31FL3741_update_pwm_buffers(DRIVER_ADDR_3, 2);
+#                if defined(DRIVER_ADDR_4)
+    IS31FL3741_update_pwm_buffers(DRIVER_ADDR_4, 3);
+#                endif
+#            endif
 #        endif
 }