warmboot: add i2c code to enable PMIC

2018-12-17 16:48:14 -08:00
parent b419c0df29
commit 754aaecc18
4 changed files with 135 additions and 1 deletions
--- a/exosphere/lp0fw/src/i2c.c
+++ b/exosphere/lp0fw/src/i2c.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2018 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+ 
+#include "i2c.h"
+#include "timer.h"
+
+/* Prototypes for internal commands. */
+void i2c_set_test_master_config_load(void);
+void i2c_write(unsigned int device, uint32_t val, unsigned int num_bytes);
+void i2c_send_byte_command(unsigned int device, unsigned char reg, unsigned char b);
+
+/* Load hardware config for I2C5. */
+void i2c_set_test_master_config_load(void) {
+    /* Set MSTR_CONFIG_LOAD. */
+    I2C_I2C_CONFIG_LOAD_0 = 0x1;
+    
+    while (!(I2C_I2C_CONFIG_LOAD_0 & 1)) {
+        /* Wait forever until it's set. */
+    }
+}
+
+/* Writes a value to an i2c device. */
+void i2c_write(unsigned int device, uint32_t val, unsigned int num_bytes) {
+    if (num_bytes > 4) {
+        return;
+    }
+
+    /* Set device for 7-bit mode. */
+    I2C_I2C_CMD_ADDR0_0 = device << 1;
+
+    /* Load in data to write. */
+    I2C_I2C_CMD_DATA1_0 = val;
+
+    /* Set config with LENGTH = num_bytes, NEW_MASTER_FSM, DEBOUNCE_CNT = 4T. */
+    I2C_I2C_CNFG_0 = ((num_bytes << 1) - 2) | 0x2800;
+
+    i2c_set_test_master_config_load();
+
+    /* Config |= SEND; */
+    I2C_I2C_CNFG_0 = ((num_bytes << 1) - 2) | 0x2800 | 0x200;
+
+
+    while (I2C_I2C_STATUS_0 & 0x100) {
+        /* Wait until not busy. */
+    }
+    
+    while (I2C_I2C_STATUS_0 & 0xF) {
+        /* Wait until write successful. */
+    }
+}
+
+/* Writes a byte val to reg for given device. */
+void i2c_send_byte_command(unsigned int device, unsigned char reg, unsigned char b) {
+    uint32_t val = (reg) | (b << 8);
+    /* Write 1 byte (reg) + 1 byte (value) */
+    i2c_write(device, val, 2);
+}
+
+/* Enable the PMIC. */
+void i2c_enable_pmic(void) {
+    /* Write 00 to Device 27 Reg 00. */
+    i2c_send_byte_command(27, 0, 0x80);
+}