1 files changed, 72 insertions, 0 deletions
diff --git a/src/soc/mediatek/common/auxadc.c b/src/soc/mediatek/common/auxadc.c
new file mode 100644
index 0000000000..6dbf12bbe9
--- /dev/null
+++ b/src/soc/mediatek/common/auxadc.c
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <assert.h>
+#include <delay.h>
+#include <device/mmio.h>
+#include <soc/addressmap.h>
+#include <soc/auxadc.h>
+#include <soc/efuse.h>
+#include <timer.h>
+
+static struct mtk_auxadc_regs *const mtk_auxadc = (void *)AUXADC_BASE;
+
+#define ADC_GE_A_SHIFT		10
+#define ADC_GE_A_MASK		(0x3ff << ADC_GE_A_SHIFT)
+#define ADC_OE_A_SHIFT		0
+#define ADC_OE_A_MASK		(0x3ff << ADC_OE_A_SHIFT)
+#define ADC_CALI_EN_A_SHIFT	20
+#define ADC_CALI_EN_A_MASK	(0x1 << ADC_CALI_EN_A_SHIFT)
+
+static int cali_oe;
+static int cali_ge;
+static int calibrated = 0;
+static void mt_auxadc_update_cali(void)
+{
+	uint32_t cali_reg;
+	int cali_ge_a;
+	int cali_oe_a;
+
+	cali_reg = read32(&mtk_efuse->adc_cali_reg);
+
+	if ((cali_reg & ADC_CALI_EN_A_MASK) != 0) {
+		cali_oe_a = (cali_reg & ADC_OE_A_MASK) >> ADC_OE_A_SHIFT;
+		cali_ge_a = (cali_reg & ADC_GE_A_MASK) >> ADC_GE_A_SHIFT;
+		cali_ge = cali_ge_a - 512;
+		cali_oe = cali_oe_a - 512;
+	}
+}
+
+static uint32_t auxadc_get_rawdata(int channel)
+{
+	setbits32(&mtk_infracfg->module_sw_cg_1_clr, 1 << 10);
+	assert(wait_ms(300, !(read32(&mtk_auxadc->con2) & 0x1)));
+
+	clrbits32(&mtk_auxadc->con1, 1 << channel);
+	assert(wait_ms(300, !(read32(&mtk_auxadc->data[channel]) & (1 << 12))));
+
+	setbits32(&mtk_auxadc->con1, 1 << channel);
+	udelay(25);
+	assert(wait_ms(300, read32(&mtk_auxadc->data[channel]) & (1 << 12)));
+
+	uint32_t value = read32(&mtk_auxadc->data[channel]) & 0x0FFF;
+
+	setbits32(&mtk_infracfg->module_sw_cg_1_set, 1 << 10);
+
+	return value;
+}
+
+unsigned int auxadc_get_voltage_uv(unsigned int channel)
+{
+	uint32_t raw_value;
+	assert(channel < 16);
+
+	if (!calibrated) {
+		mt_auxadc_update_cali();
+		calibrated = 1;
+	}
+
+	/* 1.5V in 4096 steps */
+	raw_value = auxadc_get_rawdata(channel);
+	raw_value = raw_value - cali_oe;
+	return (unsigned int)((int64_t)raw_value * 1500000 / (4096 + cali_ge));
+}