diff options
Diffstat (limited to 'chip/lm4/adc.c')
| -rw-r--r-- | chip/lm4/adc.c | 135 |
1 files changed, 63 insertions, 72 deletions
diff --git a/chip/lm4/adc.c b/chip/lm4/adc.c index 531411fd21..740c9a623d 100644 --- a/chip/lm4/adc.c +++ b/chip/lm4/adc.c @@ -3,9 +3,9 @@ * found in the LICENSE file. */ -/* ADC module for Chrome EC */ +/* LM4-specific ADC module for Chrome EC */ -#include "board.h" +#include "lm4_adc.h" #include "console.h" #include "adc.h" #include "timer.h" @@ -13,6 +13,7 @@ #include "uart.h" #include "util.h" +extern const struct adc_t adc_channels[ADC_CH_COUNT]; static void configure_gpio(void) { @@ -22,16 +23,13 @@ static void configure_gpio(void) LM4_SYSTEM_RCGCGPIO |= 0x0010; scratch = LM4_SYSTEM_RCGCGPIO; - /* Use analog function for PE3 (AIN0) */ + /* Use analog function for PE3 (AIN0) */ LM4_GPIO_DEN(LM4_GPIO_E) &= ~0x08; LM4_GPIO_AMSEL(LM4_GPIO_E) |= 0x08; } - -int adc_read(enum adc_channel ch) +int lm4_adc_flush_and_read(enum lm4_adc_sequencer seq) { - volatile uint32_t scratch __attribute__((unused)); - /* TODO: right now we have only a single channel so this is * simple. When we have multiple channels, should we... * @@ -44,84 +42,95 @@ int adc_read(enum adc_channel ch) * callers; doesn't matter if just used for debugging. * * 3) Both? */ - if (ch != ADC_CH_POT) - return ADC_READ_ERROR; - - /* Empty the FIFO of any previous results */ - while (!(LM4_ADC_SSFSTAT(0) & 0x100)) - scratch = LM4_ADC_SSFIFO(0); - - /* Clear the interrupt status */ - LM4_ADC_ADCISC |= 0x01; - - /* Initiate sample sequence */ - LM4_ADC_ADCPSSI |= 0x01; - - /* Wait for interrupt */ - /* TODO: use a real interrupt */ - while (!(LM4_ADC_ADCRIS & 0x01)); - - /* Read the FIFO */ - return LM4_ADC_SSFIFO(0); -} - - -int adc_read_ec_temperature(void) -{ volatile uint32_t scratch __attribute__((unused)); - int a; /* Empty the FIFO of any previous results */ - while (!(LM4_ADC_SSFSTAT(3) & 0x100)) - scratch = LM4_ADC_SSFIFO(3); + while (!(LM4_ADC_SSFSTAT(seq) & 0x100)) + scratch = LM4_ADC_SSFIFO(seq); /* Clear the interrupt status */ - LM4_ADC_ADCISC |= 0x08; + LM4_ADC_ADCISC |= 0x01 << seq; /* Initiate sample sequence */ - LM4_ADC_ADCPSSI |= 0x08; + LM4_ADC_ADCPSSI |= 0x01 << seq; /* Wait for interrupt */ /* TODO: use a real interrupt */ /* TODO: timeout */ - while (!(LM4_ADC_ADCRIS & 0x08)); + while (!(LM4_ADC_ADCRIS & (0x01 << seq))); /* Read the FIFO and convert to temperature */ - a = LM4_ADC_SSFIFO(3); - return 273 + (295 - (225 * 2 * a) / ADC_READ_MAX) / 2; + return LM4_ADC_SSFIFO(seq); } +int lm4_adc_configure(enum lm4_adc_sequencer seq, + int ain_id, + int ssctl) +{ + volatile uint32_t scratch __attribute__((unused)); + /* TODO: set up clock using ADCCC register? */ + /* Configure sample sequencer */ + LM4_ADC_ADCACTSS &= ~(0x01 << seq); + /* Trigger sequencer by processor request */ + LM4_ADC_ADCEMUX = (LM4_ADC_ADCEMUX & ~(0xf << (seq * 4))) | 0x00; + /* Sample internal temp sensor */ + if (ain_id != LM4_AIN_NONE) { + LM4_ADC_SSMUX(seq) = ain_id & 0xf; + LM4_ADC_SSEMUX(seq) = ain_id >> 4; + } + else { + LM4_ADC_SSMUX(seq) = 0x00; + LM4_ADC_SSEMUX(seq) = 0x00; + } + LM4_ADC_SSCTL(seq) = ssctl; + /* Enable sample sequencer */ + LM4_ADC_ADCACTSS |= 0x01 << seq; -/*****************************************************************************/ -/* Console commands */ + return EC_SUCCESS; +} -static int command_adc(int argc, char **argv) +int adc_read_channel(enum adc_channel ch) { - uart_printf("ADC channel %d = 0x%03x\n", ADC_IN0, - adc_read(ADC_CH_POT)); - return EC_SUCCESS; + const struct adc_t *adc = adc_channels + ch; + int rv = lm4_adc_flush_and_read(adc->sequencer); + return rv * adc->factor_mul / adc->factor_div + adc->shift; } -DECLARE_CONSOLE_COMMAND(adc, command_adc); +/*****************************************************************************/ +/* Console commands */ static int command_ectemp(int argc, char **argv) { - int t = adc_read_ec_temperature(); + int t = adc_read_channel(ADC_CH_EC_TEMP); uart_printf("EC temperature is %d K = %d C\n", t, t-273); return EC_SUCCESS; } DECLARE_CONSOLE_COMMAND(ectemp, command_ectemp); +static int command_adc(int argc, char **argv) +{ + int i; + for (i = 0; i < ADC_CH_COUNT; ++i) + uart_printf("ADC channel \"%s\" = %d\n", + adc_channels[i].name, + adc_read_channel(i)); + + return EC_SUCCESS; +} +DECLARE_CONSOLE_COMMAND(adc, command_adc); + +/*****************************************************************************/ /* Initialization */ int adc_init(void) { - volatile uint32_t scratch __attribute__((unused)); + int i; + const struct adc_t *adc; /* Enable ADC0 module and delay a few clocks */ LM4_SYSTEM_RCGCADC |= 0x01; - scratch = LM4_SYSTEM_RCGCADC; + udelay(1); /* Configure GPIOs */ configure_gpio(); @@ -130,29 +139,11 @@ int adc_init(void) * VDDA and GNDA. */ LM4_ADC_ADCCTL = 0x01; - /* TODO: set up clock using ADCCC register? */ - - /* Configure sample sequencer 0 */ - LM4_ADC_ADCACTSS &= ~0x01; - /* Trigger SS0 by processor request */ - LM4_ADC_ADCEMUX = (LM4_ADC_ADCEMUX & 0xfffffff0) | 0x00; - /* Sample only our one channel */ - LM4_ADC_SSMUX(0) = ADC_IN0 & 0x0f; - LM4_ADC_SSEMUX(0) = (ADC_IN0 >> 4) & 0x0f; - LM4_ADC_SSCTL(0) = 0x06; /* IE0 | END0 */ - /* Enable sample sequencer 0 */ - LM4_ADC_ADCACTSS |= 0x01; - - /* Configure sample sequencer 3 */ - LM4_ADC_ADCACTSS &= ~0x08; - /* Trigger SS3 by processor request */ - LM4_ADC_ADCEMUX = (LM4_ADC_ADCEMUX & 0xffffff0f) | 0x00; - /* Sample internal temp sensor */ - LM4_ADC_SSMUX(3) = 0x00; - LM4_ADC_SSEMUX(3) = 0x00; - LM4_ADC_SSCTL(3) = 0x0e; /* TS0 | IE0 | END0 */ - /* Enable sample sequencer 3 */ - LM4_ADC_ADCACTSS |= 0x08; + /* Initialize ADC sequencer */ + for (i = 0; i < ADC_CH_COUNT; ++i) { + adc = adc_channels + i; + lm4_adc_configure(adc->sequencer, adc->channel, adc->flag); + } return EC_SUCCESS; } |