[PATCH] iio: adc: stm32-dfsdm: Add support for stm32mp1

From: Fabrice Gasnier
Date: Wed May 02 2018 - 09:06:39 EST


Add support for DFSDM (Digital Filter For Sigma Delta Modulators)
to STM32MP1. This variant is close to STM32H7 DFSDM, it implements
6 filter instances. Registers map is also increased.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
---
.../bindings/iio/adc/st,stm32-dfsdm-adc.txt | 7 +++++--
drivers/iio/adc/stm32-dfsdm-core.c | 21 +++++++++++++++++++++
2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.txt b/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.txt
index ed7520d..75ba25d 100644
--- a/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.txt
+++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.txt
@@ -8,14 +8,16 @@ It is mainly targeted for:
- PDM microphones (audio digital microphone)

It features up to 8 serial digital interfaces (SPI or Manchester) and
-up to 4 filters on stm32h7.
+up to 4 filters on stm32h7 or 6 filters on stm32mp1.

Each child node match with a filter instance.

Contents of a STM32 DFSDM root node:
------------------------------------
Required properties:
-- compatible: Should be "st,stm32h7-dfsdm".
+- compatible: Should be one of:
+ "st,stm32h7-dfsdm"
+ "st,stm32mp1-dfsdm"
- reg: Offset and length of the DFSDM block register set.
- clocks: IP and serial interfaces clocking. Should be set according
to rcc clock ID and "clock-names".
@@ -45,6 +47,7 @@ Required properties:
"st,stm32-dfsdm-adc" for sigma delta ADCs
"st,stm32-dfsdm-dmic" for audio digital microphone.
- reg: Specifies the DFSDM filter instance used.
+ Valid values are from 0 to 3 on stm32h7, 0 to 5 on stm32mp1.
- interrupts: IRQ lines connected to each DFSDM filter instance.
- st,adc-channels: List of single-ended channels muxed for this ADC.
valid values:
diff --git a/drivers/iio/adc/stm32-dfsdm-core.c b/drivers/iio/adc/stm32-dfsdm-core.c
index e50efdc..d924e6c 100644
--- a/drivers/iio/adc/stm32-dfsdm-core.c
+++ b/drivers/iio/adc/stm32-dfsdm-core.c
@@ -25,6 +25,8 @@ struct stm32_dfsdm_dev_data {

#define STM32H7_DFSDM_NUM_FILTERS 4
#define STM32H7_DFSDM_NUM_CHANNELS 8
+#define STM32MP1_DFSDM_NUM_FILTERS 6
+#define STM32MP1_DFSDM_NUM_CHANNELS 8

static bool stm32_dfsdm_volatile_reg(struct device *dev, unsigned int reg)
{
@@ -61,6 +63,21 @@ static bool stm32_dfsdm_volatile_reg(struct device *dev, unsigned int reg)
.regmap_cfg = &stm32h7_dfsdm_regmap_cfg,
};

+static const struct regmap_config stm32mp1_dfsdm_regmap_cfg = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = sizeof(u32),
+ .max_register = 0x7fc,
+ .volatile_reg = stm32_dfsdm_volatile_reg,
+ .fast_io = true,
+};
+
+static const struct stm32_dfsdm_dev_data stm32mp1_dfsdm_data = {
+ .num_filters = STM32MP1_DFSDM_NUM_FILTERS,
+ .num_channels = STM32MP1_DFSDM_NUM_CHANNELS,
+ .regmap_cfg = &stm32mp1_dfsdm_regmap_cfg,
+};
+
struct dfsdm_priv {
struct platform_device *pdev; /* platform device */

@@ -243,6 +260,10 @@ static int stm32_dfsdm_parse_of(struct platform_device *pdev,
.compatible = "st,stm32h7-dfsdm",
.data = &stm32h7_dfsdm_data,
},
+ {
+ .compatible = "st,stm32mp1-dfsdm",
+ .data = &stm32mp1_dfsdm_data,
+ },
{}
};
MODULE_DEVICE_TABLE(of, stm32_dfsdm_of_match);
--
1.9.1