drivers/B91/adc.c

/******************************************************************************
 * Copyright (c) 2022 Telink Semiconductor (Shanghai) Co., Ltd. ("TELINK")
 * All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 *****************************************************************************/

#include "adc.h"
#include "audio.h"
#include "compiler.h"

_attribute_data_retention_sec_ unsigned short g_adc_vref = 1175;  // default ADC ref voltage (unit:mV)
volatile unsigned char g_adc_pre_scale;
volatile unsigned char g_adc_vbat_divider;

dma_chn_e adc_dma_chn;
dma_config_t adc_rx_dma_config = {
    .dst_req_sel = 0,
    .src_req_sel = DMA_REQ_AUDIO1_RX,  // adc use the audio1 interface
    .dst_addr_ctrl = DMA_ADDR_INCREMENT,
    .src_addr_ctrl = DMA_ADDR_FIX,
    .dstmode = DMA_NORMAL_MODE,
    .srcmode = DMA_HANDSHAKE_MODE,
    .dstwidth = DMA_CTR_WORD_WIDTH,  // must word
    .srcwidth = DMA_CTR_WORD_WIDTH,  // must word
    .src_burst_size = 0,             // must 0
    .read_num_en = 0,
    .priority = 0,
    .write_num_en = 0,
    .auto_en = 0,  // must 0
};
/**
 * @brief     This function serves to config adc_dma_chn channel.
 * @param[in]  chn - the DMA channel
 * @return    none
 */
void adc_set_dma_config(dma_chn_e chn)
{
    adc_dma_chn = chn;
    dma_config(chn, &adc_rx_dma_config);
    dma_clr_irq_mask(adc_dma_chn, TC_MASK | ERR_MASK | ABT_MASK);
    dma_set_irq_mask(adc_dma_chn, TC_MASK);

    audio_data_fifo1_path_sel(SAR_ADC_DATA_IN_FIFO, OUT_NO_USE);  // connect DMA and ADC by audio input fifo1.
}
/**
 * @brief     This function serves to start sample with adc DMA channel.
 * @param[in] adc_data_buf 	- the address of data buffer
 * @param[in] data_byte_len - the length of data size by byte
 * @return    none
 */
void adc_start_sample_dma(unsigned short *adc_data_buf, unsigned int data_byte_len)
{
    dma_set_address(adc_dma_chn, reg_fifo_buf_adr(1), (unsigned int)convert_ram_addr_cpu2bus(adc_data_buf));
    dma_set_size(adc_dma_chn, data_byte_len, DMA_WORD_WIDTH);
    dma_chn_en(adc_dma_chn);
    adc_fifo_enable();
}
/**
 * @brief     This function serves to get adc DMA sample status.
 * @return    	0: the sample is in progress.
 * 				!0: the sample is finished.
 */
unsigned char adc_get_sample_status_dma(void)
{
    return (dma_get_tc_irq_status(1 << adc_dma_chn));
}
/**
 * @brief     This function serves to clear adc DMA sample status.
 * @return    none
 */
void adc_clr_sample_status_dma(void)
{
    dma_chn_dis(adc_dma_chn);
    dma_clr_tc_irq_status(1 << adc_dma_chn);
}
/**
 * @brief     This function serves to stop adc DMA sample.
 * @return    none
 * @attention  function disable adc sample fifo, next sample should enable it.
 */
void adc_stop_sample_dma(void)
{
    adc_fifo_disable();
}
/**
 * @brief This function is used to set IO port for ADC supply or ADC IO port voltage sampling.
 * @param[in]  mode - ADC gpio pin sample mode
 * @param[in]  pin - adc_input_pin_def_e ADC input gpio pin
 * @return none
 */
void adc_pin_config(adc_input_pin_mode_e mode, adc_input_pin_def_e pin)
{
    unsigned short adc_input_pin = pin & 0xfff;
    switch (mode) {
        case ADC_GPIO_MODE:
            gpio_function_en(adc_input_pin);
            gpio_input_dis(adc_input_pin);
            gpio_output_dis(adc_input_pin);
            gpio_set_low_level(adc_input_pin);
            break;
        case ADC_VBAT_MODE:
            gpio_function_en(adc_input_pin);
            gpio_input_dis(adc_input_pin);
            gpio_output_en(adc_input_pin);
            gpio_set_high_level(adc_input_pin);
            break;
    }
}
/**
 * @brief This function is used to set two IO port configuration
 * and set it as input channel of ADC difference IO port voltage sampling.
 * @param[in]  p_pin - enum variable of ADC analog positive input IO.
 * @param[in]  n_pin - enum variable of ADC analog negative input IO.
 * @return none
 */
void adc_set_diff_pin(adc_input_pin_def_e p_pin, adc_input_pin_def_e n_pin)
{
    adc_pin_config(ADC_GPIO_MODE, p_pin);
    adc_pin_config(ADC_GPIO_MODE, n_pin);
    adc_set_diff_input(p_pin >> 12, n_pin >> 12);
}
/**
 * @brief This function serves to set the channel reference voltage.
 * @param[in]  v_ref - enum variable of ADC reference voltage.
 * @return none
 */
void adc_set_ref_voltage(adc_ref_vol_e v_ref)
{
    analog_write_reg8(areg_adc_vref, v_ref);
    if (v_ref == ADC_VREF_1P2V) {
        // Vref buffer bias current trimming: 		150%
        // Comparator preamp bias current trimming:  100%
        analog_write_reg8(areg_ain_scale, (analog_read_reg8(areg_ain_scale) & (0xC0)) | 0x3d);
        g_adc_vref = 1175;
    } else if (v_ref == ADC_VREF_0P9V) {
        // Vref buffer bias current trimming: 		100%
        // Comparator preamp bias current trimming:  100%
        analog_write_reg8(areg_ain_scale, (analog_read_reg8(areg_ain_scale) & (0xC0)) | 0x15);
        g_adc_vref = 900;  // v_ref = ADC_VREF_0P9V,
    }
}
/**
 * @brief This function serves to set the sample frequency.
 * @param[in]  sample_freq - enum variable of ADC sample frequency.
 * @return none
 */
void adc_set_sample_rate(adc_sample_freq_e sample_freq)
{
    switch (sample_freq) {
        case ADC_SAMPLE_FREQ_23K:
            adc_set_state_length(1023, 15);
            break;
        case ADC_SAMPLE_FREQ_48K:
            adc_set_state_length(490, 10);
            break;
        case ADC_SAMPLE_FREQ_96K:
            adc_set_state_length(240, 10);
            break;
    }
}
/**
 * @brief This function serves to set pre_scaling factor.
 * @param[in]  pre_scale - enum variable of ADC pre_scaling factor.
 * @return none
 */
void adc_set_scale_factor(adc_pre_scale_e pre_scale)
{
    analog_write_reg8(areg_ain_scale, (analog_read_reg8(areg_ain_scale) & (~FLD_SEL_AIN_SCALE)) | (pre_scale << 6));
    g_adc_pre_scale = 1 << (unsigned char)pre_scale;
}
/**
 * @brief      This function serves to select Vbat voltage division factor
 * @param[in]  vbat_div - enum variable of Vbat division factor.
 * @return     none
 */
void adc_set_vbat_divider(adc_vbat_div_e vbat_div)
{
    analog_write_reg8(areg_adc_vref_vbat_div,
                      (analog_read_reg8(areg_adc_vref_vbat_div) & (~FLD_ADC_VREF_VBAT_DIV)) | (vbat_div << 2));
    if (vbat_div) {
        g_adc_vbat_divider = 5 - vbat_div;
    } else {
        g_adc_vbat_divider = 1;
    }
}
/**
 * @brief This function serves to ADC init.
 * @param[in]  v_ref - enum variable of ADC reference voltage.
 * @param[in]  pre_scale - enum variable of ADC pre_scaling factor.
 * @param[in]  sample_freq - enum variable of ADC sample frequency.
 * @return none
 * @attention Many features are configured in adc_init function. But some features
 * 		such as adc_clk, resolution, tsample_cycle, we think better to set as default value,
 * 		and user don't need to change them in most use cases.
 */
void adc_init(adc_ref_vol_e v_ref, adc_pre_scale_e pre_scale, adc_sample_freq_e sample_freq)
{
    adc_power_off();                          // power off sar adc
    adc_reset();                              // reset whole digital adc module
    adc_clk_en();                             // enable signal of 24M clock to sar adc
    adc_set_clk(5);                           // default adc_clk 4M = 24M/(1+div),
    adc_set_ref_voltage(v_ref);               // set channel Vref
    adc_set_scale_factor(pre_scale);          // set Analog input pre-scaling
    adc_set_sample_rate(sample_freq);         // set sample frequency.
    adc_set_resolution(ADC_RES14);            // default adc_resolution set as 14bit ,BIT(13) is sign bit
    adc_set_tsample_cycle(ADC_SAMPLE_CYC_6);  // 6 adc clocks for sample cycle
    adc_set_m_chn_en();                       // enable adc channel.
}
/**
 * @brief This function serves to ADC gpio sample init.
 * @param[in]  pin - adc_input_pin_def_e ADC input gpio pin
 * @param[in]  v_ref - enum variable of ADC reference voltage.
 * @param[in]  pre_scale - enum variable of ADC pre_scaling factor.
 * @param[in]  sample_freq - enum variable of ADC sample frequency.
 * @return none
 * @attention gpio voltage sample suggested initial setting are Vref = 1.2V, pre_scale = 1/8.
 * 			0.9V Vref pre_scale must be 1.
 * 			The sampling range are as follows:
 * 			Vref        pre_scale        sampling range
 * 			1.2V			1				0 ~ 1.1V (suggest)
 * 			1.2V			1/8				0 ~ 3.5V (suggest)
 * 			0.9V            1				0 ~ 0.8V
 */
void adc_gpio_sample_init(adc_input_pin_def_e pin, adc_ref_vol_e v_ref, adc_pre_scale_e pre_scale,
                          adc_sample_freq_e sample_freq)
{
    adc_init(v_ref, pre_scale, sample_freq);
    adc_set_vbat_divider(ADC_VBAT_DIV_OFF);
    adc_pin_config(ADC_GPIO_MODE, pin);
    adc_set_diff_input(pin >> 12, GND);
}
/**
 * @brief This function servers to initialized ADC temperature sensor.When the reference voltage is set to 1.2V, and
 * at the same time, the division factor is set to 1 the most accurate.
 * @return     none.
 * @attention Temperature sensor suggested initial setting are Vref = 1.2V, pre_scale = 1.
 * 			The user don't need to change it.
 */
void adc_temperature_sample_init(void)
{
    adc_init(ADC_VREF_1P2V, ADC_PRESCALE_1, ADC_SAMPLE_FREQ_96K);
    adc_set_diff_input(ADC_TEMSENSORP_EE, ADC_TEMSENSORN_EE);
    adc_set_vbat_divider(ADC_VBAT_DIV_OFF);
    adc_temp_sensor_power_on();
}

/**
 * @brief This function servers to set ADC configuration for ADC supply voltage sampling.
 * @return none
 * @attention battery voltage sample suggested initial setting are Vref = 1.2V, pre_scale = 1, vbat_div = 1/3.
 * 			Which has higher accuracy, user don't need to change it.
 * 			The battery voltage sample range is 1.8~3.5V,
 * 			and must set sys_init with the mode for battery voltage less than 3.6V.
 * 			For battery voltage > 3.6V, should take some external voltage divider.
 */
void adc_battery_voltage_sample_init(void)
{
    adc_init(ADC_VREF_1P2V, ADC_PRESCALE_1, ADC_SAMPLE_FREQ_96K);
    adc_set_vbat_divider(ADC_VBAT_DIV_1F3);
    adc_set_diff_input(ADC_VBAT, GND);
}
/**
 * @brief This function serves to start adc sample and get raw adc sample code.
 * @param[in]   sample_buffer 		- pointer to the buffer adc sample code need to store.
 * @param[in]   sample_num 			- the number of adc sample code.
 * @return 		none
 */
void adc_get_code_dma(unsigned short *sample_buffer, unsigned short sample_num)
{
    /******start adc sample********/
    adc_start_sample_dma((unsigned short *)sample_buffer, sample_num << 1);
    /******wait for adc sample finish********/
    while (!adc_get_sample_status_dma()) {
    }
    /******stop dma smaple********/
    adc_stop_sample_dma();
    /******clear adc sample finished status********/
    adc_clr_sample_status_dma();  // must
    /******get adc sample data and sort these data ********/
    for (int i = 0; i < sample_num; i++) {
        if (sample_buffer[i] &
            BIT(13)) {  // 14 bit resolution, BIT(13) is sign bit, 1 means negative voltage in differential_mode
            sample_buffer[i] = 0;
        } else {
            sample_buffer[i] = (sample_buffer[i] & 0x1fff);  // BIT(12..0) is valid adc code
        }
    }
}
/**
 * @brief This function serves to directly get an adc sample code from analog registers.
 * 		If you want to get the sampling results twice in succession,
 *       Must ensure that the sampling interval is more than 2 times the sampling period.
 * @return 	adc_code 	- the adc sample code.
 */
unsigned short adc_get_code(void)
{
    unsigned short adc_code;
    /******Lock ADC code in analog register ********/
    analog_write_reg8(areg_adc_data_sample_control,
                      analog_read_reg8(areg_adc_data_sample_control) | FLD_NOT_SAMPLE_ADC_DATA);
    adc_code = analog_read_reg16(areg_adc_misc_l);
    analog_write_reg8(areg_adc_data_sample_control,
                      analog_read_reg8(areg_adc_data_sample_control) & (~FLD_NOT_SAMPLE_ADC_DATA));

    if (adc_code & BIT(13)) {
        adc_code = 0;
    } else {
        adc_code &= 0x1FFF;
    }
    return adc_code;
}
/**
 * @brief This function serves to calculate voltage from adc sample code.
 * @param[in]   adc_code	- the adc sample code.
 * @return 		adc_vol_mv 	- the average value of adc voltage value.
 */
unsigned short adc_calculate_voltage(unsigned short adc_code)
{
    //////////////// adc sample data convert to voltage(mv) ////////////////
    //                          (Vref, adc_pre_scale)   (BIT<12~0> valid data)
    //			 =  adc_code * Vref * adc_pre_scale / 0x2000
    //           =  adc_code * Vref * adc_pre_scale >>13
    return ((adc_code * g_adc_vbat_divider * g_adc_pre_scale * g_adc_vref) >> 13);
}
/**
 * @brief This function serves to calculate temperature from temperature sensor adc sample code.
 * @param[in]   adc_code	 		- the temperature sensor adc sample code.
 * @return 		adc_temp_value	 	- the of temperature value.
 * attention   Temperature and adc_code are linearly related.
 *             We test four chips between -40~130 (Celsius) and got an average ratio:
 * 			   Temp =  564 - ((adc_code * 819)>>13),when Vref = 1.2V, pre_scale = 1.
 */
unsigned short adc_calculate_temperature(unsigned short adc_code)
{
    //////////////// adc sample data convert to temperature(Celsius) ////////////////
    // adc_temp_value = 564 - ((adc_code * 819)>>13)
    return 564 - ((adc_code * 819) >> 13);
}