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path: root/drivers/iio/adc/at91-sama5d2_adc.c
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Diffstat (limited to 'drivers/iio/adc/at91-sama5d2_adc.c')
-rw-r--r--drivers/iio/adc/at91-sama5d2_adc.c102
1 files changed, 74 insertions, 28 deletions
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index 2e154cb51..e10dca3ed 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -66,8 +66,10 @@
#define AT91_SAMA5D2_MR_PRESCAL(v) ((v) << AT91_SAMA5D2_MR_PRESCAL_OFFSET)
#define AT91_SAMA5D2_MR_PRESCAL_OFFSET 8
#define AT91_SAMA5D2_MR_PRESCAL_MAX 0xff
+#define AT91_SAMA5D2_MR_PRESCAL_MASK GENMASK(15, 8)
/* Startup Time */
#define AT91_SAMA5D2_MR_STARTUP(v) ((v) << 16)
+#define AT91_SAMA5D2_MR_STARTUP_MASK GENMASK(19, 16)
/* Analog Change */
#define AT91_SAMA5D2_MR_ANACH BIT(23)
/* Tracking Time */
@@ -92,13 +94,13 @@
/* Last Converted Data Register */
#define AT91_SAMA5D2_LCDR 0x20
/* Interrupt Enable Register */
-#define AT91_SAMA5D2_IER 0x24
+#define AT91_SAMA5D2_IER 0x24
/* Interrupt Disable Register */
-#define AT91_SAMA5D2_IDR 0x28
+#define AT91_SAMA5D2_IDR 0x28
/* Interrupt Mask Register */
-#define AT91_SAMA5D2_IMR 0x2c
+#define AT91_SAMA5D2_IMR 0x2c
/* Interrupt Status Register */
-#define AT91_SAMA5D2_ISR 0x30
+#define AT91_SAMA5D2_ISR 0x30
/* Last Channel Trigger Mode Register */
#define AT91_SAMA5D2_LCTMR 0x34
/* Last Channel Compare Window Register */
@@ -106,17 +108,20 @@
/* Overrun Status Register */
#define AT91_SAMA5D2_OVER 0x3c
/* Extended Mode Register */
-#define AT91_SAMA5D2_EMR 0x40
+#define AT91_SAMA5D2_EMR 0x40
/* Compare Window Register */
-#define AT91_SAMA5D2_CWR 0x44
+#define AT91_SAMA5D2_CWR 0x44
/* Channel Gain Register */
-#define AT91_SAMA5D2_CGR 0x48
+#define AT91_SAMA5D2_CGR 0x48
+
/* Channel Offset Register */
-#define AT91_SAMA5D2_COR 0x4c
+#define AT91_SAMA5D2_COR 0x4c
+#define AT91_SAMA5D2_COR_DIFF_OFFSET 16
+
/* Channel Data Register 0 */
#define AT91_SAMA5D2_CDR0 0x50
/* Analog Control Register */
-#define AT91_SAMA5D2_ACR 0x94
+#define AT91_SAMA5D2_ACR 0x94
/* Touchscreen Mode Register */
#define AT91_SAMA5D2_TSMR 0xb0
/* Touchscreen X Position Register */
@@ -130,7 +135,7 @@
/* Correction Select Register */
#define AT91_SAMA5D2_COSR 0xd0
/* Correction Value Register */
-#define AT91_SAMA5D2_CVR 0xd4
+#define AT91_SAMA5D2_CVR 0xd4
/* Channel Error Correction Register */
#define AT91_SAMA5D2_CECR 0xd8
/* Write Protection Mode Register */
@@ -140,7 +145,7 @@
/* Version Register */
#define AT91_SAMA5D2_VERSION 0xfc
-#define AT91_AT91_SAMA5D2_CHAN(num, addr) \
+#define AT91_SAMA5D2_CHAN_SINGLE(num, addr) \
{ \
.type = IIO_VOLTAGE, \
.channel = num, \
@@ -156,6 +161,24 @@
.indexed = 1, \
}
+#define AT91_SAMA5D2_CHAN_DIFF(num, num2, addr) \
+ { \
+ .type = IIO_VOLTAGE, \
+ .differential = 1, \
+ .channel = num, \
+ .channel2 = num2, \
+ .address = addr, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 12, \
+ }, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\
+ .datasheet_name = "CH"#num"-CH"#num2, \
+ .indexed = 1, \
+ }
+
#define at91_adc_readl(st, reg) readl_relaxed(st->base + reg)
#define at91_adc_writel(st, reg, val) writel_relaxed(val, st->base + reg)
@@ -185,18 +208,24 @@ struct at91_adc_state {
};
static const struct iio_chan_spec at91_adc_channels[] = {
- AT91_AT91_SAMA5D2_CHAN(0, 0x50),
- AT91_AT91_SAMA5D2_CHAN(1, 0x54),
- AT91_AT91_SAMA5D2_CHAN(2, 0x58),
- AT91_AT91_SAMA5D2_CHAN(3, 0x5c),
- AT91_AT91_SAMA5D2_CHAN(4, 0x60),
- AT91_AT91_SAMA5D2_CHAN(5, 0x64),
- AT91_AT91_SAMA5D2_CHAN(6, 0x68),
- AT91_AT91_SAMA5D2_CHAN(7, 0x6c),
- AT91_AT91_SAMA5D2_CHAN(8, 0x70),
- AT91_AT91_SAMA5D2_CHAN(9, 0x74),
- AT91_AT91_SAMA5D2_CHAN(10, 0x78),
- AT91_AT91_SAMA5D2_CHAN(11, 0x7c),
+ AT91_SAMA5D2_CHAN_SINGLE(0, 0x50),
+ AT91_SAMA5D2_CHAN_SINGLE(1, 0x54),
+ AT91_SAMA5D2_CHAN_SINGLE(2, 0x58),
+ AT91_SAMA5D2_CHAN_SINGLE(3, 0x5c),
+ AT91_SAMA5D2_CHAN_SINGLE(4, 0x60),
+ AT91_SAMA5D2_CHAN_SINGLE(5, 0x64),
+ AT91_SAMA5D2_CHAN_SINGLE(6, 0x68),
+ AT91_SAMA5D2_CHAN_SINGLE(7, 0x6c),
+ AT91_SAMA5D2_CHAN_SINGLE(8, 0x70),
+ AT91_SAMA5D2_CHAN_SINGLE(9, 0x74),
+ AT91_SAMA5D2_CHAN_SINGLE(10, 0x78),
+ AT91_SAMA5D2_CHAN_SINGLE(11, 0x7c),
+ AT91_SAMA5D2_CHAN_DIFF(0, 1, 0x50),
+ AT91_SAMA5D2_CHAN_DIFF(2, 3, 0x58),
+ AT91_SAMA5D2_CHAN_DIFF(4, 5, 0x60),
+ AT91_SAMA5D2_CHAN_DIFF(6, 7, 0x68),
+ AT91_SAMA5D2_CHAN_DIFF(8, 9, 0x70),
+ AT91_SAMA5D2_CHAN_DIFF(10, 11, 0x78),
};
static unsigned at91_adc_startup_time(unsigned startup_time_min,
@@ -226,7 +255,7 @@ static unsigned at91_adc_startup_time(unsigned startup_time_min,
static void at91_adc_setup_samp_freq(struct at91_adc_state *st, unsigned freq)
{
struct iio_dev *indio_dev = iio_priv_to_dev(st);
- unsigned f_per, prescal, startup;
+ unsigned f_per, prescal, startup, mr;
f_per = clk_get_rate(st->per_clk);
prescal = (f_per / (2 * freq)) - 1;
@@ -234,10 +263,11 @@ static void at91_adc_setup_samp_freq(struct at91_adc_state *st, unsigned freq)
startup = at91_adc_startup_time(st->soc_info.startup_time,
freq / 1000);
- at91_adc_writel(st, AT91_SAMA5D2_MR,
- AT91_SAMA5D2_MR_TRANSFER(2)
- | AT91_SAMA5D2_MR_STARTUP(startup)
- | AT91_SAMA5D2_MR_PRESCAL(prescal));
+ mr = at91_adc_readl(st, AT91_SAMA5D2_MR);
+ mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK);
+ mr |= AT91_SAMA5D2_MR_STARTUP(startup);
+ mr |= AT91_SAMA5D2_MR_PRESCAL(prescal);
+ at91_adc_writel(st, AT91_SAMA5D2_MR, mr);
dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u\n",
freq, startup, prescal);
@@ -278,6 +308,7 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev,
int *val, int *val2, long mask)
{
struct at91_adc_state *st = iio_priv(indio_dev);
+ u32 cor = 0;
int ret;
switch (mask) {
@@ -286,6 +317,11 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev,
st->chan = chan;
+ if (chan->differential)
+ cor = (BIT(chan->channel) | BIT(chan->channel2)) <<
+ AT91_SAMA5D2_COR_DIFF_OFFSET;
+
+ at91_adc_writel(st, AT91_SAMA5D2_COR, cor);
at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));
at91_adc_writel(st, AT91_SAMA5D2_IER, BIT(chan->channel));
at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START);
@@ -298,6 +334,8 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev,
if (ret > 0) {
*val = st->conversion_value;
+ if (chan->scan_type.sign == 's')
+ *val = sign_extend32(*val, 11);
ret = IIO_VAL_INT;
st->conversion_done = false;
}
@@ -310,6 +348,8 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_SCALE:
*val = st->vref_uv / 1000;
+ if (chan->differential)
+ *val *= 2;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
@@ -444,6 +484,12 @@ static int at91_adc_probe(struct platform_device *pdev)
at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST);
at91_adc_writel(st, AT91_SAMA5D2_IDR, 0xffffffff);
+ /*
+ * Transfer field must be set to 2 according to the datasheet and
+ * allows different analog settings for each channel.
+ */
+ at91_adc_writel(st, AT91_SAMA5D2_MR,
+ AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH);
at91_adc_setup_samp_freq(st, st->soc_info.min_sample_rate);