From 5177b02ab02bc18f8d8465d58b02486cf6124317 Mon Sep 17 00:00:00 2001
From: true <true_git@truecontrol.org>
Date: Sat, 3 Aug 2024 11:40:10 -0700
Subject: [PATCH] i2c, IS31FL3729 cleanup

---
 firmware/retro_tech_fw/user/main.c         | 11 +++++---
 firmware/retro_tech_fw/user/src/31fl3729.c | 30 +++++++++++-----------
 firmware/retro_tech_fw/user/src/31fl3729.h |  2 +-
 firmware/retro_tech_fw/user/src/i2c.c      |  6 +----
 4 files changed, 24 insertions(+), 25 deletions(-)

diff --git a/firmware/retro_tech_fw/user/main.c b/firmware/retro_tech_fw/user/main.c
index 72629ac..cbfefde 100644
--- a/firmware/retro_tech_fw/user/main.c
+++ b/firmware/retro_tech_fw/user/main.c
@@ -44,7 +44,7 @@ void gpio_init()
 
     gpio.GPIO_Speed = GPIO_Speed_2MHz;
 
-    // Soft I2C, USART TX/RX; currently unused
+    // GAT SoftI2C, USART TX/RX; currently unused
     gpio.GPIO_Mode = GPIO_Mode_IPD;
     gpio.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_6;
     GPIO_Init(GPIOD, &gpio);
@@ -65,10 +65,13 @@ void gpio_init()
     gpio.GPIO_Pin = GPIO_Pin_2;
     GPIO_Init(GPIOD, &gpio);
 
-    // I2C will be handled by the driver
+    // I2C SCL, SCA for on-board devices
+    gpio.GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_2;
+    gpio.GPIO_Mode = GPIO_Mode_AF_OD;
+    GPIO_Init(GPIOC, &gpio);
 
-    // IS_SDB IS31FL3729 shutdown pin (active low)
-    // WP for EEPROM
+    // IS_SDB (PC3) IS31FL3729 shutdown pin (active low)
+    // WP (PC6) for EEPROM
     GPIOC->BCR = GPIO_Pin_3;
     GPIOC->BSHR = GPIO_Pin_6;
     gpio.GPIO_Mode = GPIO_Mode_Out_PP;
diff --git a/firmware/retro_tech_fw/user/src/31fl3729.c b/firmware/retro_tech_fw/user/src/31fl3729.c
index 2832a42..099b52a 100644
--- a/firmware/retro_tech_fw/user/src/31fl3729.c
+++ b/firmware/retro_tech_fw/user/src/31fl3729.c
@@ -9,11 +9,23 @@
 #include "i2c.h"
 
 
-/* sends the IS31FL3729 general config.
+
+void is31fl3729_set_global_current(uint8_t i2c_addr, uint8_t global_current)
+{
+    i2c_write_reg_8b(i2c_addr, FL3729_REG_G_CURRENT, global_current);
+}
+
+void is31fl3729_set_scaling_current(uint8_t i2c_addr, uint8_t cs, uint8_t current)
+{
+    if (cs > 0xf) return;
+
+    i2c_write_reg_8b(i2c_addr, FL3729_REG_SCALING + cs, current);
+}
+
+/* sends the IS31FL3729 initial config.
  * does not configure per-channel current sink limits; do that separately.
  * does not configure other sane defaults; do that separately.
  */
-
 void is31fl3729_init(uint8_t i2c_addr, uint8_t config, uint8_t global_current)
 {
     // enable device
@@ -26,7 +38,7 @@ void is31fl3729_init(uint8_t i2c_addr, uint8_t config, uint8_t global_current)
 
     // write initial config
     i2c_write_reg_8b(i2c_addr, FL3729_REG_CONFIG, config);
-    i2c_write_reg_8b(i2c_addr, FL3729_REG_G_CURRENT, global_current);
+    is31fl3729_set_global_current(i2c_addr, global_current);
 }
 
 uint8_t is31fl3729_get_addr(uint8_t adpin)
@@ -35,18 +47,6 @@ uint8_t is31fl3729_get_addr(uint8_t adpin)
 }
 
 
-void is31fl3729_set_global_current(uint8_t i2c_addr, uint8_t current)
-{
-    i2c_write_reg_8b(i2c_addr, FL3729_REG_G_CURRENT, current);
-}
-
-void is31fl3729_set_scaling_current(uint8_t i2c_addr, uint8_t cs, uint8_t current)
-{
-    if (cs > 0xf) return;
-
-    i2c_write_reg_8b(i2c_addr, FL3729_REG_SCALING + cs, current);
-}
-
 /*
  * sets current limit of multiple outputs simultaneously, starting from CS1.
  * useful for initial register configuration.
diff --git a/firmware/retro_tech_fw/user/src/31fl3729.h b/firmware/retro_tech_fw/user/src/31fl3729.h
index 3e4f0c9..320ab95 100644
--- a/firmware/retro_tech_fw/user/src/31fl3729.h
+++ b/firmware/retro_tech_fw/user/src/31fl3729.h
@@ -72,7 +72,7 @@ void is31fl3729_init(uint8_t i2c_addr, uint8_t config, uint8_t global_current);
 
 uint8_t is31fl3729_get_addr(uint8_t adpin);
 
-void is31fl3729_set_global_current(uint8_t i2c_addr, uint8_t current);
+void is31fl3729_set_global_current(uint8_t i2c_addr, uint8_t global_current);
 void is31fl3729_set_scaling_current(uint8_t i2c_addr, uint8_t cs, uint8_t current);
 void is31fl3729_set_scaling_current_multi(uint8_t i2c_addr, const uint8_t *current, uint8_t count);
 
diff --git a/firmware/retro_tech_fw/user/src/i2c.c b/firmware/retro_tech_fw/user/src/i2c.c
index d32145f..f332540 100644
--- a/firmware/retro_tech_fw/user/src/i2c.c
+++ b/firmware/retro_tech_fw/user/src/i2c.c
@@ -23,13 +23,9 @@ static uint32_t timeout;
 
 void i2c_init()
 {
-    GPIO_InitTypeDef gpio = {0};
     I2C_InitTypeDef i2c = {0};
 
-    gpio.GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_2;
-    gpio.GPIO_Mode = GPIO_Mode_AF_OD;
-    gpio.GPIO_Speed = GPIO_Speed_2MHz;
-    GPIO_Init(GPIOC, &gpio);
+    // ensure GPIO pins are configured before initializing
 
     i2c.I2C_ClockSpeed = 666666;
     i2c.I2C_Mode = I2C_Mode_I2C;