soc/mediatek/mt8195: add mt6691 driver
Add mt6691 buck control for DRAM to run fast calibration test.
It is needed to get and set voltage during testing.
Signed-off-by: Henry Chen <henryc.chen@mediatek.com>
Change-Id: I4fb9f7245d44383a6a3a0cf8d00f7f503cbdeb06
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55575
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/mediatek/mt8195/mt6691.c b/src/soc/mediatek/mt8195/mt6691.c
new file mode 100644
index 0000000..3f22421
--- /dev/null
+++ b/src/soc/mediatek/mt8195/mt6691.c
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+#include <device/i2c_simple.h>
+#include <soc/mt6691.h>
+
+#define MT6691_MIN_VOLTAGE 300000
+#define MT6691_MAX_VOLTAGE 1300000
+#define MT6691_STEP_UV 5000
+
+enum {
+ MT6691_SLAVE_ADDR = 0x51,
+};
+
+int mt6691_set_voltage(uint8_t i2c_num, unsigned int volt_uv)
+{
+ uint8_t selector;
+
+ if (volt_uv > MT6691_MAX_VOLTAGE || volt_uv < MT6691_MIN_VOLTAGE) {
+ printk(BIOS_ERR, "%s: voltage out of range\n", __func__);
+ return -1;
+ }
+
+ selector = DIV_ROUND_UP(volt_uv - MT6691_MIN_VOLTAGE, MT6691_STEP_UV);
+
+ return i2c_write_field(i2c_num, MT6691_SLAVE_ADDR,
+ MT6691_VSEL0, selector, 0xFF, 0);
+}
+
+int mt6691_get_voltage(uint8_t i2c_num)
+{
+ uint8_t selector = 0;
+ unsigned int volt;
+
+ if (i2c_read_field(i2c_num, MT6691_SLAVE_ADDR, MT6691_VSEL0,
+ &selector, 0xFF, 0) < 0) {
+ printk(BIOS_ERR, "%s: failed to get voltage from i2c\n", __func__);
+ return -1;
+ }
+
+ volt = (selector * MT6691_STEP_UV) + MT6691_MIN_VOLTAGE;
+
+ if (volt > MT6691_MAX_VOLTAGE) {
+ printk(BIOS_ERR, "%s: voltage out of range\n", __func__);
+ return -1;
+ }
+
+ return volt;
+}
+
+static uint8_t get_mt6691_chip_id(uint8_t i2c_num)
+{
+ uint8_t id;
+
+ if (i2c_read_field(i2c_num, MT6691_SLAVE_ADDR, MT6691_MONITOR,
+ &id, 0x1, MT6691_PGOOD_SHIFT) < 0) {
+ printk(BIOS_ERR, "%s: failed to read from i2c", __func__);
+ return 0;
+ }
+
+ return id;
+}
+
+void mt6691_probe(uint8_t i2c_num)
+{
+ /* Check device ID is MT6691 */
+ if (!get_mt6691_chip_id(i2c_num)) {
+ printk(BIOS_ERR, "ERROR: unknown MT6691 chip_id\n");
+ return;
+ }
+ /* Slew rate 12mV */
+ i2c_write_field(i2c_num, MT6691_SLAVE_ADDR, MT6691_CTRL2, 0x1,
+ MT6691_DN_SR_MASK, MT6691_DN_SR_SHIFT);
+}