diff options
Diffstat (limited to 'drivers/iio/adc/aspeed_adc.c')
| -rw-r--r-- | drivers/iio/adc/aspeed_adc.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c index e0ea411a0b2d..c02b23d675cb 100644 --- a/drivers/iio/adc/aspeed_adc.c +++ b/drivers/iio/adc/aspeed_adc.c @@ -22,6 +22,7 @@ #include <linux/iio/iio.h> #include <linux/iio/driver.h> +#include <linux/iopoll.h> #define ASPEED_RESOLUTION_BITS 10 #define ASPEED_CLOCKS_PER_SAMPLE 12 @@ -38,11 +39,17 @@ #define ASPEED_ENGINE_ENABLE BIT(0) +#define ASPEED_ADC_CTRL_INIT_RDY BIT(8) + +#define ASPEED_ADC_INIT_POLLING_TIME 500 +#define ASPEED_ADC_INIT_TIMEOUT 500000 + struct aspeed_adc_model_data { const char *model_name; unsigned int min_sampling_rate; // Hz unsigned int max_sampling_rate; // Hz unsigned int vref_voltage; // mV + bool wait_init_sequence; }; struct aspeed_adc_data { @@ -211,6 +218,24 @@ static int aspeed_adc_probe(struct platform_device *pdev) goto scaler_error; } + model_data = of_device_get_match_data(&pdev->dev); + + if (model_data->wait_init_sequence) { + /* Enable engine in normal mode. */ + writel(ASPEED_OPERATION_MODE_NORMAL | ASPEED_ENGINE_ENABLE, + data->base + ASPEED_REG_ENGINE_CONTROL); + + /* Wait for initial sequence complete. */ + ret = readl_poll_timeout(data->base + ASPEED_REG_ENGINE_CONTROL, + adc_engine_control_reg_val, + adc_engine_control_reg_val & + ASPEED_ADC_CTRL_INIT_RDY, + ASPEED_ADC_INIT_POLLING_TIME, + ASPEED_ADC_INIT_TIMEOUT); + if (ret) + goto scaler_error; + } + /* Start all channels in normal mode. */ ret = clk_prepare_enable(data->clk_scaler->clk); if (ret) @@ -274,6 +299,7 @@ static const struct aspeed_adc_model_data ast2500_model_data = { .vref_voltage = 1800, // mV .min_sampling_rate = 1, .max_sampling_rate = 1000000, + .wait_init_sequence = true, }; static const struct of_device_id aspeed_adc_matches[] = { |