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Message-Id: <20250129-wip-bl-ad7606_add_backend_sw_mode-v3-7-c3aec77c0ab7@baylibre.com>
Date: Wed, 29 Jan 2025 12:03:08 +0100
From: Angelo Dureghello <adureghello@...libre.com>
To: Michael Hennerich <michael.hennerich@...log.com>,
Lars-Peter Clausen <lars@...afoo.de>, Jonathan Cameron <jic23@...nel.org>,
Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>,
Alexandru Ardelean <aardelean@...libre.com>,
David Lechner <dlechner@...libre.com>
Cc: Jonathan Cameron <Jonathan.Cameron@...wei.com>,
linux-fbdev@...r.kernel.org, linux-iio@...r.kernel.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
Guillaume Stols <gstols@...libre.com>,
Angelo Dureghello <adureghello@...libre.com>
Subject: [PATCH v3 07/10] iio: adc: adi-axi-adc: add support for AD7606
register writing
From: Guillaume Stols <gstols@...libre.com>
Since we must access the bus parallel bus using a custom procedure,
let's add a specialized compatible, and define specialized callbacks for
writing the registers using the parallel interface.
Signed-off-by: Guillaume Stols <gstols@...libre.com>
Co-developed-by: Angelo Dureghello <adureghello@...libre.com>
Signed-off-by: Angelo Dureghello <adureghello@...libre.com>
---
drivers/iio/adc/adi-axi-adc.c | 100 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 100 insertions(+)
diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index 0923565cf5bb..aaeb445a8a3e 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -27,6 +27,7 @@
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
+#include "ad7606_bus_iface.h"
/*
* Register definitions:
* https://wiki.analog.com/resources/fpga/docs/axi_adc_ip#register_map
@@ -73,6 +74,12 @@
#define ADI_AXI_ADC_REG_DELAY(l) (0x0800 + (l) * 0x4)
#define AXI_ADC_DELAY_CTRL_MASK GENMASK(4, 0)
+#define ADI_AXI_REG_CONFIG_WR 0x0080
+#define ADI_AXI_REG_CONFIG_RD 0x0084
+#define ADI_AXI_REG_CONFIG_CTRL 0x008c
+#define ADI_AXI_REG_CONFIG_CTRL_READ 0x03
+#define ADI_AXI_REG_CONFIG_CTRL_WRITE 0x01
+
#define ADI_AXI_ADC_MAX_IO_NUM_LANES 15
#define ADI_AXI_REG_CHAN_CTRL_DEFAULTS \
@@ -80,6 +87,10 @@
ADI_AXI_REG_CHAN_CTRL_FMT_EN | \
ADI_AXI_REG_CHAN_CTRL_ENABLE)
+#define ADI_AXI_REG_READ_BIT 0x8000
+#define ADI_AXI_REG_ADDRESS_MASK 0xff00
+#define ADI_AXI_REG_VALUE_MASK 0x00ff
+
struct axi_adc_info {
unsigned int version;
const struct iio_backend_info *backend_info;
@@ -313,6 +324,81 @@ static struct iio_buffer *axi_adc_request_buffer(struct iio_backend *back,
return iio_dmaengine_buffer_setup(st->dev, indio_dev, dma_name);
}
+static int axi_adc_raw_write(struct iio_backend *back, void *buf, unsigned int len)
+{
+ struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+ u32 data;
+
+ data = *(u32 *)(buf);
+
+ regmap_write(st->regmap, ADI_AXI_REG_CONFIG_WR, data);
+ regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL,
+ ADI_AXI_REG_CONFIG_CTRL_WRITE);
+ usleep_range(50, 100);
+ regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL, 0x00);
+ usleep_range(50, 100);
+
+ return 0;
+}
+
+static int axi_adc_raw_read(struct iio_backend *back, void *buf, unsigned int len)
+{
+ struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+ u32 *bdata = buf;
+
+ regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL,
+ ADI_AXI_REG_CONFIG_CTRL_READ);
+ usleep_range(50, 100);
+ regmap_read(st->regmap, ADI_AXI_REG_CONFIG_RD, bdata);
+ regmap_write(st->regmap, ADI_AXI_REG_CONFIG_CTRL, 0x00);
+ usleep_range(50, 100);
+
+ return 0;
+}
+
+static int ad7606_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val)
+{
+ struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+ u32 buf;
+
+ guard(mutex)(&st->lock);
+
+ /*
+ * The address is written on the highest weight byte, and the MSB set
+ * at 1 indicates a read operation.
+ */
+ buf = FIELD_PREP(ADI_AXI_REG_ADDRESS_MASK, reg) | ADI_AXI_REG_READ_BIT;
+ axi_adc_raw_write(back, &buf, sizeof(buf));
+ axi_adc_raw_read(back, val, 4);
+
+ /* Write 0x0 on the bus to get back to ADC mode */
+ buf = 0;
+ axi_adc_raw_write(back, &buf, sizeof(buf));
+ return 0;
+}
+
+static int ad7606_bus_reg_write(struct iio_backend *back, u32 reg, u32 val)
+{
+ struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+ u32 buf;
+
+ guard(mutex)(&st->lock);
+
+ /* Write any register to switch to register mode */
+ buf = 0xaf00;
+ axi_adc_raw_write(back, &buf, sizeof(buf));
+
+ buf = FIELD_PREP(ADI_AXI_REG_ADDRESS_MASK, reg) |
+ FIELD_PREP(ADI_AXI_REG_VALUE_MASK, val);
+ axi_adc_raw_write(back, &buf, sizeof(buf));
+
+ /* Write 0x0 on the bus to get back to ADC mode */
+ buf = 0;
+ axi_adc_raw_write(back, &buf, sizeof(buf));
+
+ return 0;
+}
+
static void axi_adc_free_buffer(struct iio_backend *back,
struct iio_buffer *buffer)
{
@@ -484,9 +570,23 @@ static const struct axi_adc_info adc_generic = {
.backend_info = &adi_axi_adc_generic,
};
+static const struct ad7606_platform_data ad7606_pdata = {
+ .bus_reg_read = ad7606_bus_reg_read,
+ .bus_reg_write = ad7606_bus_reg_write,
+};
+
+static const struct axi_adc_info adc_ad7606 = {
+ .version = ADI_AXI_PCORE_VER(10, 0, 'a'),
+ .backend_info = &adi_axi_adc_generic,
+ .bus_controller = true,
+ .pdata = &ad7606_pdata,
+ .pdata_sz = sizeof(ad7606_pdata),
+};
+
/* Match table for of_platform binding */
static const struct of_device_id adi_axi_adc_of_match[] = {
{ .compatible = "adi,axi-adc-10.0.a", .data = &adc_generic },
+ { .compatible = "adi,axi-ad7606x", .data = &adc_ad7606 },
{ /* end of list */ }
};
MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);
--
2.47.0
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