iio: adc: at91-sama5d2_adc: handle different EMR.OSR for different hw versions

SAMA7G5 introduces 64 and 256 oversampling rates. Due to this EMR.OSR is 3
bits long. Change the code to reflect this. Commit prepares the code
for the addition of 64 and 256 oversampling rates.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-7-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index 64943d8..0283c8c 100644 (file)
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -138,8 +138,7 @@ struct at91_adc_reg_layout {
 /* Extended Mode Register */
        u16                             EMR;
 /* Extended Mode Register - Oversampling rate */
-#define AT91_SAMA5D2_EMR_OSR(V)                        ((V) << 16)
-#define AT91_SAMA5D2_EMR_OSR_MASK              GENMASK(17, 16)
+#define AT91_SAMA5D2_EMR_OSR(V, M)             (((V) << 16) & (M))
 #define AT91_SAMA5D2_EMR_OSR_1SAMPLES          0
 #define AT91_SAMA5D2_EMR_OSR_4SAMPLES          1
 #define AT91_SAMA5D2_EMR_OSR_16SAMPLES         2
@@ -403,6 +402,7 @@ static const struct at91_adc_reg_layout sama7g5_layout = {
  * @max_index:         highest channel index (highest index may be higher
  *                     than the total channel number)
  * @hw_trig_cnt:       number of possible hardware triggers
+ * @osr_mask:          oversampling ratio bitmask on EMR register
  */
 struct at91_adc_platform {
        const struct at91_adc_reg_layout        *layout;
@@ -414,6 +414,7 @@ struct at91_adc_platform {
        unsigned int                            max_channels;
        unsigned int                            max_index;
        unsigned int                            hw_trig_cnt;
+       unsigned int                            osr_mask;
 };
 
 /**
@@ -612,6 +613,7 @@ static const struct at91_adc_platform sama5d2_platform = {
        .max_index = AT91_SAMA5D2_MAX_CHAN_IDX,
 #define AT91_SAMA5D2_HW_TRIG_CNT       3
        .hw_trig_cnt = AT91_SAMA5D2_HW_TRIG_CNT,
+       .osr_mask = GENMASK(17, 16),
 };
 
 static const struct at91_adc_platform sama7g5_platform = {
@@ -627,6 +629,7 @@ static const struct at91_adc_platform sama7g5_platform = {
        .max_index = AT91_SAMA7G5_MAX_CHAN_IDX,
 #define AT91_SAMA7G5_HW_TRIG_CNT       3
        .hw_trig_cnt = AT91_SAMA7G5_HW_TRIG_CNT,
+       .osr_mask = GENMASK(18, 16),
 };
 
 static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan)
@@ -725,30 +728,32 @@ static void at91_adc_eoc_ena(struct at91_adc_state *st, unsigned int channel)
                at91_adc_writel(st, EOC_IER, BIT(channel));
 }
 
-static void at91_adc_config_emr(struct at91_adc_state *st)
+static void at91_adc_config_emr(struct at91_adc_state *st,
+                               u32 oversampling_ratio)
 {
        /* configure the extended mode register */
        unsigned int emr = at91_adc_readl(st, EMR);
+       unsigned int osr_mask = st->soc_info.platform->osr_mask;
 
        /* select oversampling per single trigger event */
        emr |= AT91_SAMA5D2_EMR_ASTE(1);
 
        /* delete leftover content if it's the case */
-       emr &= ~AT91_SAMA5D2_EMR_OSR_MASK;
+       emr &= ~osr_mask;
 
        /* select oversampling ratio from configuration */
-       switch (st->oversampling_ratio) {
+       switch (oversampling_ratio) {
        case AT91_OSR_1SAMPLES:
-               emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_1SAMPLES) &
-                      AT91_SAMA5D2_EMR_OSR_MASK;
+               emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_1SAMPLES,
+                                           osr_mask);
                break;
        case AT91_OSR_4SAMPLES:
-               emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_4SAMPLES) &
-                      AT91_SAMA5D2_EMR_OSR_MASK;
+               emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_4SAMPLES,
+                                           osr_mask);
                break;
        case AT91_OSR_16SAMPLES:
-               emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES) &
-                      AT91_SAMA5D2_EMR_OSR_MASK;
+               emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES,
+                                           osr_mask);
                break;
        }
 
@@ -1658,7 +1663,7 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev,
                mutex_lock(&st->lock);
                st->oversampling_ratio = val;
                /* update ratio */
-               at91_adc_config_emr(st);
+               at91_adc_config_emr(st, val);
                mutex_unlock(&st->lock);
                iio_device_release_direct_mode(indio_dev);
                return 0;
@@ -1838,7 +1843,7 @@ static void at91_adc_hw_init(struct iio_dev *indio_dev)
        at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate);
 
        /* configure extended mode register */
-       at91_adc_config_emr(st);
+       at91_adc_config_emr(st, st->oversampling_ratio);
 }
 
 static ssize_t at91_adc_get_fifo_state(struct device *dev,