Merge tag 'driver-core-4.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git...

[karo-tx-linux.git] / drivers / iio / adc / aspeed_adc.c

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index e0ea411a0b2df9563085c70552086946843ba2ca..c02b23d675cbc1540ec47769515da714c784cf67 100644 (file)
--- 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[] = {