There are actually 4 configuration modes of clock source for AD719X
devices. Either a crystal can be attached externally between MCLK1 and
MCLK2 pins, or an external CMOS-compatible clock can drive the MCLK2
pin. The other 2 modes make use of the 4.92MHz internal clock.
Undocumented properties adi,int-clock-output-enable and adi,clock-xtal
still supported for backward compatibility, but their use is highly
discouraged. Use cleaner alternative of configuring external clock by
using clock names mclk and xtal.
Functionality of AD7192_CLK_INT_CO will be implemented in complementary
patch by adding clock provider.
Signed-off-by: Alisa-Dariana Roman <alisa.roman@xxxxxxxxxx>
---
drivers/iio/adc/ad7192.c | 91 +++++++++++++++++++++++++++-------------
1 file changed, 63 insertions(+), 28 deletions(-)
diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
index 334ab90991d4..042319f0c641 100644
--- a/drivers/iio/adc/ad7192.c
+++ b/drivers/iio/adc/ad7192.c
@@ -396,25 +396,72 @@ static inline bool ad7192_valid_external_frequency(u32 freq)
freq <= AD7192_EXT_FREQ_MHZ_MAX);
}
-static int ad7192_clock_select(struct ad7192_state *st)
+/*
+ * Position 0 of ad7192_clock_names, xtal, corresponds to clock source
+ * configuration AD7192_CLK_EXT_MCLK1_2 and position 1, mclk, corresponds to
+ * AD7192_CLK_EXT_MCLK2
+ */
+static const char *const ad7192_clock_names[] = {
+ "xtal",
+ "mclk"
+};
+
+static int ad7192_clock_setup(struct ad7192_state *st)
{
struct device *dev = &st->sd.spi->dev;
- unsigned int clock_sel;
+ int ret;
- clock_sel = AD7192_CLK_INT;
+ /*
+ * The following two if branches are kept for backward compatibility but
+ * the use of the two devicetree properties is highly discouraged. Clock
+ * configuration should be done according to the bindings.
+ */
- /* use internal clock */
- if (!st->mclk) {
- if (device_property_read_bool(dev, "adi,int-clock-output-enable"))
- clock_sel = AD7192_CLK_INT_CO;
- } else {
- if (device_property_read_bool(dev, "adi,clock-xtal"))
- clock_sel = AD7192_CLK_EXT_MCLK1_2;
- else
- clock_sel = AD7192_CLK_EXT_MCLK2;
+ if (device_property_read_bool(dev, "adi,int-clock-output-enable")) {
+ st->clock_sel = AD7192_CLK_INT_CO;
+ st->fclk = AD7192_INT_FREQ_MHZ;
+ dev_warn(dev, "Property adi,int-clock-output-enable is deprecated! Check bindings!\n");
+ return 0;
}
- return clock_sel;
+ if (device_property_read_bool(dev, "adi,clock-xtal")) {
+ st->clock_sel = AD7192_CLK_EXT_MCLK1_2;
+ st->mclk = devm_clk_get_enabled(dev, "mclk");
+ if (IS_ERR(st->mclk))
+ return dev_err_probe(dev, PTR_ERR(st->mclk),
+ "Failed to get mclk\n");
+
+ st->fclk = clk_get_rate(st->mclk);
+ if (!ad7192_valid_external_frequency(st->fclk))
+ return dev_err_probe(dev, -EINVAL,
+ "External clock frequency out of bounds\n");
+
+ dev_warn(dev, "Property adi,clock-xtal is deprecated! Check bindings!\n");
+ return 0;
+ }
+
+ ret = device_property_match_property_string(dev, "clock-names",
+ ad7192_clock_names,
+ ARRAY_SIZE(ad7192_clock_names));
+ if (ret < 0) {
+ st->clock_sel = AD7192_CLK_INT;
+ st->fclk = AD7192_INT_FREQ_MHZ;
+ return 0;
+ }
+
+ st->clock_sel = AD7192_CLK_EXT_MCLK1_2 + ret;
+
+ st->mclk = devm_clk_get_enabled(dev, ad7192_clock_names[ret]);
+ if (IS_ERR(st->mclk))
+ return dev_err_probe(dev, PTR_ERR(st->mclk),
+ "Failed to get clock source\n");
+
+ st->fclk = clk_get_rate(st->mclk);
+ if (!ad7192_valid_external_frequency(st->fclk))
+ return dev_err_probe(dev, -EINVAL,
+ "External clock frequency out of bounds\n");
+
+ return 0;
}
static int ad7192_setup(struct iio_dev *indio_dev, struct device *dev)
@@ -1275,21 +1322,9 @@ static int ad7192_probe(struct spi_device *spi)
if (ret)
return ret;
- st->fclk = AD7192_INT_FREQ_MHZ;
-
- st->mclk = devm_clk_get_optional_enabled(dev, "mclk");
- if (IS_ERR(st->mclk))
- return PTR_ERR(st->mclk);
-
- st->clock_sel = ad7192_clock_select(st);
-
- if (st->clock_sel == AD7192_CLK_EXT_MCLK1_2 ||
- st->clock_sel == AD7192_CLK_EXT_MCLK2) {
- st->fclk = clk_get_rate(st->mclk);
- if (!ad7192_valid_external_frequency(st->fclk))
- return dev_err_probe(dev, -EINVAL,
- "External clock frequency out of bounds\n");
- }
+ ret = ad7192_clock_setup(st);
+ if (ret)
+ return ret;
ret = ad7192_setup(indio_dev, dev);
if (ret)
--
2.34.1
