[PATCH v5 06/10] iio: dac: adi-axi-dac: extend features

Angelo Dureghello posted 10 patches 1 month, 2 weeks ago
There is a newer version of this series
[PATCH v5 06/10] iio: dac: adi-axi-dac: extend features
Posted by Angelo Dureghello 1 month, 2 weeks ago
From: Angelo Dureghello <adureghello@baylibre.com>

Extend AXI-DAC backend with new features required to interface
to the ad3552r DAC. Mainly, a new compatible string is added to
support the ad3552r-axi DAC IP, very similar to the generic DAC
IP but with some customizations to work with the ad3552r.

Then, a serie of generic functions has been added to match with
ad3552r needs. Function names has been kept generic as much as
possible, to allow re-utilization from other frontend drivers.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 drivers/iio/dac/adi-axi-dac.c | 285 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 274 insertions(+), 11 deletions(-)

diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
index 04193a98616e..e43d0ecccb50 100644
--- a/drivers/iio/dac/adi-axi-dac.c
+++ b/drivers/iio/dac/adi-axi-dac.c
@@ -46,9 +46,28 @@
 #define AXI_DAC_CNTRL_1_REG			0x0044
 #define   AXI_DAC_CNTRL_1_SYNC			BIT(0)
 #define AXI_DAC_CNTRL_2_REG			0x0048
+#define   AXI_DAC_CNTRL_2_SDR_DDR_N		BIT(16)
+#define   AXI_DAC_CNTRL_2_SYMB_8B		BIT(14)
 #define   ADI_DAC_CNTRL_2_R1_MODE		BIT(5)
+#define   AXI_DAC_CNTRL_2_UNSIGNED_DATA		BIT(4)
+#define AXI_DAC_STATUS_1_REG			0x0054
+#define AXI_DAC_STATUS_2_REG			0x0058
 #define AXI_DAC_DRP_STATUS_REG			0x0074
 #define   AXI_DAC_DRP_STATUS_DRP_LOCKED		BIT(17)
+#define AXI_DAC_CUSTOM_RD_REG			0x0080
+#define AXI_DAC_CUSTOM_WR_REG			0x0084
+#define   AXI_DAC_CUSTOM_WR_DATA_8		GENMASK(23, 16)
+#define   AXI_DAC_CUSTOM_WR_DATA_16		GENMASK(23, 8)
+#define AXI_DAC_UI_STATUS_REG			0x0088
+#define   AXI_DAC_UI_STATUS_IF_BUSY		BIT(4)
+#define AXI_DAC_CUSTOM_CTRL_REG			0x008C
+#define   AXI_DAC_CUSTOM_CTRL_ADDRESS		GENMASK(31, 24)
+#define   AXI_DAC_CUSTOM_CTRL_SYNCED_TRANSFER	BIT(2)
+#define   AXI_DAC_CUSTOM_CTRL_STREAM		BIT(1)
+#define   AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA	BIT(0)
+
+#define AXI_DAC_STREAM_ENABLE			(AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA | \
+						AXI_DAC_CUSTOM_CTRL_STREAM)
 
 /* DAC Channel controls */
 #define AXI_DAC_CHAN_CNTRL_1_REG(c)		(0x0400 + (c) * 0x40)
@@ -63,12 +82,27 @@
 #define AXI_DAC_CHAN_CNTRL_7_REG(c)		(0x0418 + (c) * 0x40)
 #define   AXI_DAC_CHAN_CNTRL_7_DATA_SEL		GENMASK(3, 0)
 
+#define AXI_DAC_RD_ADDR(x)			(BIT(7) | (x))
+
 /* 360 degrees in rad */
 #define AXI_DAC_2_PI_MEGA			6283190
 
 enum {
 	AXI_DAC_DATA_INTERNAL_TONE,
 	AXI_DAC_DATA_DMA = 2,
+	AXI_DAC_DATA_INTERNAL_RAMP_16BIT = 11,
+};
+
+enum {
+	AXI_DAC_BUS_TYPE_NONE,
+	AXI_DAC_BUS_TYPE_DDR_QSPI,
+};
+
+struct axi_dac_info {
+	unsigned int version;
+	const struct iio_backend_info *backend_info;
+	bool bus_controller;
+	bool has_dac_clk;
 };
 
 struct axi_dac_state {
@@ -79,9 +113,12 @@ struct axi_dac_state {
 	 * data/variables.
 	 */
 	struct mutex lock;
+	const struct axi_dac_info *info;
+	struct clk *clk;
 	u64 dac_clk;
 	u32 reg_config;
 	bool int_tone;
+	int dac_clk_rate;
 };
 
 static int axi_dac_enable(struct iio_backend *back)
@@ -471,6 +508,11 @@ static int axi_dac_data_source_set(struct iio_backend *back, unsigned int chan,
 					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
 					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
 					  AXI_DAC_DATA_DMA);
+	case IIO_BACKEND_INTERNAL_RAMP_16BIT:
+		return regmap_update_bits(st->regmap,
+					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
+					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
+					  AXI_DAC_DATA_INTERNAL_RAMP_16BIT);
 	default:
 		return -EINVAL;
 	}
@@ -528,6 +570,186 @@ static int axi_dac_reg_access(struct iio_backend *back, unsigned int reg,
 	return regmap_write(st->regmap, reg, writeval);
 }
 
+static int axi_dac_ddr_enable(struct iio_backend *back)
+{
+	struct axi_dac_state *st = iio_backend_get_priv(back);
+
+	return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
+				 AXI_DAC_CNTRL_2_SDR_DDR_N);
+}
+
+static int axi_dac_ddr_disable(struct iio_backend *back)
+{
+	struct axi_dac_state *st = iio_backend_get_priv(back);
+
+	return regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
+			       AXI_DAC_CNTRL_2_SDR_DDR_N);
+}
+
+static int axi_dac_data_stream_enable(struct iio_backend *back)
+{
+	struct axi_dac_state *st = iio_backend_get_priv(back);
+
+	return regmap_set_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
+			       AXI_DAC_STREAM_ENABLE);
+}
+
+static int axi_dac_data_stream_disable(struct iio_backend *back)
+{
+	struct axi_dac_state *st = iio_backend_get_priv(back);
+
+	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
+				 AXI_DAC_STREAM_ENABLE);
+}
+
+static int axi_dac_data_transfer_addr(struct iio_backend *back, u32 address)
+{
+	struct axi_dac_state *st = iio_backend_get_priv(back);
+
+	/*
+	 * Sample register address, when the DAC is configured, or stream
+	 * start address when the FSM is in stream state.
+	 */
+	return regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
+				  AXI_DAC_CUSTOM_CTRL_ADDRESS,
+				  FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS,
+				  address));
+}
+
+static int axi_dac_data_format_set(struct iio_backend *back, unsigned int ch,
+				   const struct iio_backend_data_fmt *data)
+{
+	struct axi_dac_state *st = iio_backend_get_priv(back);
+	int err;
+
+	switch (data->type) {
+	case IIO_BACKEND_DATA_UNSIGNED:
+		err = regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
+					AXI_DAC_CNTRL_2_UNSIGNED_DATA);
+		if (err)
+			return err;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int axi_dac_read_raw(struct iio_backend *back,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct axi_dac_state *st = iio_backend_get_priv(back);
+	int err;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_FREQUENCY: {
+		int reg;
+
+		if (!st->info->has_dac_clk)
+			return -EOPNOTSUPP;
+
+		/*
+		 * As from ad3552r AXI IP documentation,
+		 * returning the SCLK depending on the stream mode.
+		 */
+		err = regmap_read(st->regmap, AXI_DAC_CUSTOM_CTRL_REG, &reg);
+		if (err)
+			return err;
+
+		if (reg & AXI_DAC_CUSTOM_CTRL_STREAM)
+			*val = st->dac_clk_rate / 2;
+		else
+			*val = st->dac_clk_rate / 8;
+
+		return IIO_VAL_INT;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int axi_dac_bus_reg_write(struct iio_backend *back, u32 reg, u32 val,
+				 size_t data_size)
+{
+	struct axi_dac_state *st = iio_backend_get_priv(back);
+	int ret;
+	u32 ival;
+
+	if (data_size == 2)
+		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_16, val);
+	else
+		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_8, val);
+
+	ret = regmap_write(st->regmap, AXI_DAC_CUSTOM_WR_REG, ival);
+	if (ret)
+		return ret;
+
+	/*
+	 * Both REG_CNTRL_2 and AXI_DAC_CNTRL_DATA_WR need to know
+	 * the data size. So keeping data size control here only,
+	 * since data size is mandatory for the current transfer.
+	 * DDR state handled separately by specific backend calls,
+	 * generally all raw register writes are SDR.
+	 */
+	if (data_size == 1)
+		ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
+				      AXI_DAC_CNTRL_2_SYMB_8B);
+	else
+		ret = regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
+					AXI_DAC_CNTRL_2_SYMB_8B);
+	if (ret)
+		return ret;
+
+	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
+				 AXI_DAC_CUSTOM_CTRL_ADDRESS,
+				 FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS, reg));
+	if (ret)
+		return ret;
+
+	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
+				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA,
+				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
+	if (ret)
+		return ret;
+
+	ret = regmap_read_poll_timeout(st->regmap,
+				       AXI_DAC_CUSTOM_CTRL_REG, ival,
+				       ival & AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA,
+				       10, 100 * KILO);
+	if (ret)
+		return ret;
+
+	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
+				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
+}
+
+static int axi_dac_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val,
+				size_t data_size)
+{
+	struct axi_dac_state *st = iio_backend_get_priv(back);
+	int ret;
+	u32 ival;
+
+	/*
+	 * SPI, we write with read flag, then we read just at the AXI
+	 * io address space to get data read.
+	 */
+	ret = axi_dac_bus_reg_write(back, AXI_DAC_RD_ADDR(reg), 0, data_size);
+	if (ret)
+		return ret;
+
+	ret = regmap_read_poll_timeout(st->regmap, AXI_DAC_UI_STATUS_REG, ival,
+				FIELD_GET(AXI_DAC_UI_STATUS_IF_BUSY, ival) !=
+				AXI_DAC_UI_STATUS_IF_BUSY,
+				10, 100);
+	if (ret)
+		return ret;
+
+	return regmap_read(st->regmap, AXI_DAC_CUSTOM_RD_REG, val);
+}
+
 static const struct iio_backend_ops axi_dac_generic_ops = {
 	.enable = axi_dac_enable,
 	.disable = axi_dac_disable,
@@ -541,11 +763,29 @@ static const struct iio_backend_ops axi_dac_generic_ops = {
 	.debugfs_reg_access = iio_backend_debugfs_ptr(axi_dac_reg_access),
 };
 
+static const struct iio_backend_ops axi_ad3552r_ops = {
+	.enable = axi_dac_enable,
+	.read_raw = axi_dac_read_raw,
+	.request_buffer = axi_dac_request_buffer,
+	.data_source_set = axi_dac_data_source_set,
+	.ddr_enable = axi_dac_ddr_enable,
+	.ddr_disable = axi_dac_ddr_disable,
+	.data_stream_enable = axi_dac_data_stream_enable,
+	.data_stream_disable = axi_dac_data_stream_disable,
+	.data_format_set = axi_dac_data_format_set,
+	.data_transfer_addr = axi_dac_data_transfer_addr,
+};
+
 static const struct iio_backend_info axi_dac_generic = {
 	.name = "axi-dac",
 	.ops = &axi_dac_generic_ops,
 };
 
+static const struct iio_backend_info axi_ad3552r = {
+	.name = "axi-ad3552r",
+	.ops = &axi_ad3552r_ops,
+};
+
 static const struct regmap_config axi_dac_regmap_config = {
 	.val_bits = 32,
 	.reg_bits = 32,
@@ -555,7 +795,6 @@ static const struct regmap_config axi_dac_regmap_config = {
 
 static int axi_dac_probe(struct platform_device *pdev)
 {
-	const unsigned int *expected_ver;
 	struct axi_dac_state *st;
 	void __iomem *base;
 	unsigned int ver;
@@ -566,15 +805,26 @@ static int axi_dac_probe(struct platform_device *pdev)
 	if (!st)
 		return -ENOMEM;
 
-	expected_ver = device_get_match_data(&pdev->dev);
-	if (!expected_ver)
+	st->info = device_get_match_data(&pdev->dev);
+	if (!st->info)
 		return -ENODEV;
 
-	clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk");
 	if (IS_ERR(clk))
 		return dev_err_probe(&pdev->dev, PTR_ERR(clk),
 				     "failed to get clock\n");
 
+	if (st->info->has_dac_clk) {
+		struct clk *dac_clk;
+
+		dac_clk = devm_clk_get_enabled(&pdev->dev, "dac_clk");
+		if (IS_ERR(dac_clk))
+			return dev_err_probe(&pdev->dev, PTR_ERR(dac_clk),
+					     "failed to get dac_clk clock\n");
+
+		st->dac_clk_rate = clk_get_rate(dac_clk);
+	}
+
 	base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(base))
 		return PTR_ERR(base);
@@ -598,12 +848,13 @@ static int axi_dac_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	if (ADI_AXI_PCORE_VER_MAJOR(ver) != ADI_AXI_PCORE_VER_MAJOR(*expected_ver)) {
+	if (ADI_AXI_PCORE_VER_MAJOR(ver) !=
+		ADI_AXI_PCORE_VER_MAJOR(st->info->version)) {
 		dev_err(&pdev->dev,
 			"Major version mismatch. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
-			ADI_AXI_PCORE_VER_MAJOR(*expected_ver),
-			ADI_AXI_PCORE_VER_MINOR(*expected_ver),
-			ADI_AXI_PCORE_VER_PATCH(*expected_ver),
+			ADI_AXI_PCORE_VER_MAJOR(st->info->version),
+			ADI_AXI_PCORE_VER_MINOR(st->info->version),
+			ADI_AXI_PCORE_VER_PATCH(st->info->version),
 			ADI_AXI_PCORE_VER_MAJOR(ver),
 			ADI_AXI_PCORE_VER_MINOR(ver),
 			ADI_AXI_PCORE_VER_PATCH(ver));
@@ -629,7 +880,8 @@ static int axi_dac_probe(struct platform_device *pdev)
 		return ret;
 
 	mutex_init(&st->lock);
-	ret = devm_iio_backend_register(&pdev->dev, &axi_dac_generic, st);
+
+	ret = devm_iio_backend_register(&pdev->dev, st->info->backend_info, st);
 	if (ret)
 		return dev_err_probe(&pdev->dev, ret,
 				     "failed to register iio backend\n");
@@ -642,10 +894,21 @@ static int axi_dac_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static unsigned int axi_dac_9_1_b_info = ADI_AXI_PCORE_VER(9, 1, 'b');
+static const struct axi_dac_info dac_generic = {
+	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
+	.backend_info = &axi_dac_generic,
+};
+
+static const struct axi_dac_info dac_ad3552r = {
+	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
+	.backend_info = &axi_ad3552r,
+	.bus_controller = true,
+	.has_dac_clk = true,
+};
 
 static const struct of_device_id axi_dac_of_match[] = {
-	{ .compatible = "adi,axi-dac-9.1.b", .data = &axi_dac_9_1_b_info },
+	{ .compatible = "adi,axi-dac-9.1.b", .data = &dac_generic },
+	{ .compatible = "adi,axi-ad3552r", .data = &dac_ad3552r },
 	{}
 };
 MODULE_DEVICE_TABLE(of, axi_dac_of_match);

-- 
2.45.0.rc1
Re: [PATCH v5 06/10] iio: dac: adi-axi-dac: extend features
Posted by Nuno Sá 1 month, 2 weeks ago
On Tue, 2024-10-08 at 17:43 +0200, Angelo Dureghello wrote:
> From: Angelo Dureghello <adureghello@baylibre.com>
> 
> Extend AXI-DAC backend with new features required to interface
> to the ad3552r DAC. Mainly, a new compatible string is added to
> support the ad3552r-axi DAC IP, very similar to the generic DAC
> IP but with some customizations to work with the ad3552r.
> 
> Then, a serie of generic functions has been added to match with
> ad3552r needs. Function names has been kept generic as much as
> possible, to allow re-utilization from other frontend drivers.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
> ---

Just some minor stuff. Not seeing any fundamental issue with this patch.

>  drivers/iio/dac/adi-axi-dac.c | 285 ++++++++++++++++++++++++++++++++++++++++-
> -
>  1 file changed, 274 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
> index 04193a98616e..e43d0ecccb50 100644
> --- a/drivers/iio/dac/adi-axi-dac.c
> +++ b/drivers/iio/dac/adi-axi-dac.c
> @@ -46,9 +46,28 @@
>  #define AXI_DAC_CNTRL_1_REG			0x0044
>  #define   AXI_DAC_CNTRL_1_SYNC			BIT(0)
>  #define AXI_DAC_CNTRL_2_REG			0x0048
> +#define   AXI_DAC_CNTRL_2_SDR_DDR_N		BIT(16)
> +#define   AXI_DAC_CNTRL_2_SYMB_8B		BIT(14)
>  #define   ADI_DAC_CNTRL_2_R1_MODE		BIT(5)
> +#define   AXI_DAC_CNTRL_2_UNSIGNED_DATA		BIT(4)
> +#define AXI_DAC_STATUS_1_REG			0x0054
> +#define AXI_DAC_STATUS_2_REG			0x0058
>  #define AXI_DAC_DRP_STATUS_REG			0x0074
>  #define   AXI_DAC_DRP_STATUS_DRP_LOCKED		BIT(17)
> +#define AXI_DAC_CUSTOM_RD_REG			0x0080
> +#define AXI_DAC_CUSTOM_WR_REG			0x0084
> +#define   AXI_DAC_CUSTOM_WR_DATA_8		GENMASK(23, 16)
> +#define   AXI_DAC_CUSTOM_WR_DATA_16		GENMASK(23, 8)
> +#define AXI_DAC_UI_STATUS_REG			0x0088
> +#define   AXI_DAC_UI_STATUS_IF_BUSY		BIT(4)
> +#define AXI_DAC_CUSTOM_CTRL_REG			0x008C
> +#define   AXI_DAC_CUSTOM_CTRL_ADDRESS		GENMASK(31, 24)
> +#define   AXI_DAC_CUSTOM_CTRL_SYNCED_TRANSFER	BIT(2)
> +#define   AXI_DAC_CUSTOM_CTRL_STREAM		BIT(1)
> +#define   AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA	BIT(0)
> +
> +#define
> AXI_DAC_STREAM_ENABLE			(AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA | \
> +						AXI_DAC_CUSTOM_CTRL_STREAM)
>  
>  /* DAC Channel controls */
>  #define AXI_DAC_CHAN_CNTRL_1_REG(c)		(0x0400 + (c) * 0x40)
> @@ -63,12 +82,27 @@
>  #define AXI_DAC_CHAN_CNTRL_7_REG(c)		(0x0418 + (c) * 0x40)
>  #define   AXI_DAC_CHAN_CNTRL_7_DATA_SEL		GENMASK(3, 0)
>  
> +#define AXI_DAC_RD_ADDR(x)			(BIT(7) | (x))
> +
>  /* 360 degrees in rad */
>  #define AXI_DAC_2_PI_MEGA			6283190
>  
>  enum {
>  	AXI_DAC_DATA_INTERNAL_TONE,
>  	AXI_DAC_DATA_DMA = 2,
> +	AXI_DAC_DATA_INTERNAL_RAMP_16BIT = 11,
> +};
> +
> +enum {
> +	AXI_DAC_BUS_TYPE_NONE,
> +	AXI_DAC_BUS_TYPE_DDR_QSPI,
> +};

Do we still need the above?

> +
> +struct axi_dac_info {
> +	unsigned int version;
> +	const struct iio_backend_info *backend_info;
> +	bool bus_controller;
> +	bool has_dac_clk;
>  };
> 
>  struct axi_dac_state {
> @@ -79,9 +113,12 @@ struct axi_dac_state {
>  	 * data/variables.
>  	 */
>  	struct mutex lock;
> +	const struct axi_dac_info *info;
> +	struct clk *clk;

Is it used?

>  	u64 dac_clk;
>  	u32 reg_config;
>  	bool int_tone;
> +	int dac_clk_rate;
>  };
>  
>  static int axi_dac_enable(struct iio_backend *back)
> @@ -471,6 +508,11 @@ static int axi_dac_data_source_set(struct iio_backend
> *back, unsigned int chan,
>  					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
>  					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
>  					  AXI_DAC_DATA_DMA);
> +	case IIO_BACKEND_INTERNAL_RAMP_16BIT:
> +		return regmap_update_bits(st->regmap,
> +					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
> +					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
> +					  AXI_DAC_DATA_INTERNAL_RAMP_16BIT);
>  	default:
>  		return -EINVAL;
>  	}
> @@ -528,6 +570,186 @@ static int axi_dac_reg_access(struct iio_backend *back,
> unsigned int reg,
>  	return regmap_write(st->regmap, reg, writeval);
>  }
>  
> +static int axi_dac_ddr_enable(struct iio_backend *back)
> +{
> +	struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> +	return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> +				 AXI_DAC_CNTRL_2_SDR_DDR_N);
> +}
> +
> +static int axi_dac_ddr_disable(struct iio_backend *back)
> +{
> +	struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> +	return regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> +			       AXI_DAC_CNTRL_2_SDR_DDR_N);
> +}
> +
> +static int axi_dac_data_stream_enable(struct iio_backend *back)
> +{
> +	struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> +	return regmap_set_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> +			       AXI_DAC_STREAM_ENABLE);
> +}
> +
> +static int axi_dac_data_stream_disable(struct iio_backend *back)
> +{
> +	struct axi_dac_state *st = iio_backend_get_priv(back);
> +
> +	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> +				 AXI_DAC_STREAM_ENABLE);
> +}
> +
> +static int axi_dac_data_transfer_addr(struct iio_backend *back, u32 address)
> +{
> +	struct axi_dac_state *st = iio_backend_get_priv(back);
> +

We could add some validation for address with FIELD_MAX()

> +	/*
> +	 * Sample register address, when the DAC is configured, or stream
> +	 * start address when the FSM is in stream state.
> +	 */
> +	return regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> +				  AXI_DAC_CUSTOM_CTRL_ADDRESS,
> +				  FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS,
> +				  address));
> +}
> +
> +static int axi_dac_data_format_set(struct iio_backend *back, unsigned int ch,
> +				   const struct iio_backend_data_fmt *data)
> +{
> +	struct axi_dac_state *st = iio_backend_get_priv(back);
> +	int err;
> 

Not sure if I mentioned it already but please use 'ret' so it's consistent with
what we have. But for this function, see below

> +	switch (data->type) {
> +	case IIO_BACKEND_DATA_UNSIGNED:
> +		err = regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> +					AXI_DAC_CNTRL_2_UNSIGNED_DATA);
> +		if (err)
> +			return err;
> +		break;
		return regmap_clear_bits();
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;

remove the above...

> +}
> +
> +static int axi_dac_read_raw(struct iio_backend *back,
> +			    struct iio_chan_spec const *chan,
> +			    int *val, int *val2, long mask)
> +{
> +	struct axi_dac_state *st = iio_backend_get_priv(back);
> +	int err;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_FREQUENCY: {
> +		int reg;

I would just declare it at top scope and remove {}. Otherwise...
> +
> +		if (!st->info->has_dac_clk)
> +			return -EOPNOTSUPP;
> +
> +		/*
> +		 * As from ad3552r AXI IP documentation,
> +		 * returning the SCLK depending on the stream mode.
> +		 */
> +		err = regmap_read(st->regmap, AXI_DAC_CUSTOM_CTRL_REG, &reg);
> +		if (err)
> +			return err;
> +
> +		if (reg & AXI_DAC_CUSTOM_CTRL_STREAM)
> +			*val = st->dac_clk_rate / 2;
> +		else
> +			*val = st->dac_clk_rate / 8;
> +
> +		return IIO_VAL_INT;
> +		}

... does not look good
 
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int axi_dac_bus_reg_write(struct iio_backend *back, u32 reg, u32 val,
> +				 size_t data_size)
> +{
> +	struct axi_dac_state *st = iio_backend_get_priv(back);
> +	int ret;
> +	u32 ival;
> +
> +	if (data_size == 2)

nit: sizeof(u16)

> +		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_16, val);
> +	else
> +		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_8, val);
> +
> +	ret = regmap_write(st->regmap, AXI_DAC_CUSTOM_WR_REG, ival);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * Both REG_CNTRL_2 and AXI_DAC_CNTRL_DATA_WR need to know
> +	 * the data size. So keeping data size control here only,
> +	 * since data size is mandatory for the current transfer.
> +	 * DDR state handled separately by specific backend calls,
> +	 * generally all raw register writes are SDR.
> +	 */
> +	if (data_size == 1)
> +		ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> +				      AXI_DAC_CNTRL_2_SYMB_8B);
> +	else
> +		ret = regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> +					AXI_DAC_CNTRL_2_SYMB_8B);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> +				 AXI_DAC_CUSTOM_CTRL_ADDRESS,
> +				 FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS,
> reg));
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> +				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA,
> +				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_read_poll_timeout(st->regmap,
> +				       AXI_DAC_CUSTOM_CTRL_REG, ival,
> +				       ival &
> AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA,
> +				       10, 100 * KILO);
> +	if (ret)
> +		return ret;
> +
> +	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> +				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
> +}
> +
> +static int axi_dac_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val,
> +				size_t data_size)
> +{
> +	struct axi_dac_state *st = iio_backend_get_priv(back);
> +	int ret;
> +	u32 ival;
> +
> +	/*
> +	 * SPI, we write with read flag, then we read just at the AXI
> +	 * io address space to get data read.
> +	 */
> +	ret = axi_dac_bus_reg_write(back, AXI_DAC_RD_ADDR(reg), 0,
> data_size);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_read_poll_timeout(st->regmap, AXI_DAC_UI_STATUS_REG,
> ival,
> +				FIELD_GET(AXI_DAC_UI_STATUS_IF_BUSY, ival) !=
> +				AXI_DAC_UI_STATUS_IF_BUSY,
> +				10, 100);
> +	if (ret)
> +		return ret;
> +
> +	return regmap_read(st->regmap, AXI_DAC_CUSTOM_RD_REG, val);
> +}
> +
>  static const struct iio_backend_ops axi_dac_generic_ops = {
>  	.enable = axi_dac_enable,
>  	.disable = axi_dac_disable,
> @@ -541,11 +763,29 @@ static const struct iio_backend_ops axi_dac_generic_ops
> = {
>  	.debugfs_reg_access = iio_backend_debugfs_ptr(axi_dac_reg_access),
>  };
>  
> +static const struct iio_backend_ops axi_ad3552r_ops = {
> +	.enable = axi_dac_enable,
> +	.read_raw = axi_dac_read_raw,
> +	.request_buffer = axi_dac_request_buffer,
> +	.data_source_set = axi_dac_data_source_set,
> +	.ddr_enable = axi_dac_ddr_enable,
> +	.ddr_disable = axi_dac_ddr_disable,
> +	.data_stream_enable = axi_dac_data_stream_enable,
> +	.data_stream_disable = axi_dac_data_stream_disable,
> +	.data_format_set = axi_dac_data_format_set,
> +	.data_transfer_addr = axi_dac_data_transfer_addr,
> +};
> +
>  static const struct iio_backend_info axi_dac_generic = {
>  	.name = "axi-dac",
>  	.ops = &axi_dac_generic_ops,
>  };
>  
> +static const struct iio_backend_info axi_ad3552r = {
> +	.name = "axi-ad3552r",
> +	.ops = &axi_ad3552r_ops,
> +};
> +
>  static const struct regmap_config axi_dac_regmap_config = {
>  	.val_bits = 32,
>  	.reg_bits = 32,
> @@ -555,7 +795,6 @@ static const struct regmap_config axi_dac_regmap_config =
> {
>  
>  static int axi_dac_probe(struct platform_device *pdev)
>  {
> -	const unsigned int *expected_ver;
>  	struct axi_dac_state *st;
>  	void __iomem *base;
>  	unsigned int ver;
> @@ -566,15 +805,26 @@ static int axi_dac_probe(struct platform_device *pdev)
>  	if (!st)
>  		return -ENOMEM;
>  
> -	expected_ver = device_get_match_data(&pdev->dev);
> -	if (!expected_ver)
> +	st->info = device_get_match_data(&pdev->dev);
> +	if (!st->info)
>  		return -ENODEV;
>  
> -	clk = devm_clk_get_enabled(&pdev->dev, NULL);
> +	clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk");
>  	if (IS_ERR(clk))
>  		return dev_err_probe(&pdev->dev, PTR_ERR(clk),
>  				     "failed to get clock\n");
>  
> +	if (st->info->has_dac_clk) {
> +		struct clk *dac_clk;
> +
> +		dac_clk = devm_clk_get_enabled(&pdev->dev, "dac_clk");
> +		if (IS_ERR(dac_clk))
> +			return dev_err_probe(&pdev->dev, PTR_ERR(dac_clk),
> +					     "failed to get dac_clk
> clock\n");
> +
> +		st->dac_clk_rate = clk_get_rate(dac_clk);
> +	}
> +
>  	base = devm_platform_ioremap_resource(pdev, 0);
>  	if (IS_ERR(base))
>  		return PTR_ERR(base);
> @@ -598,12 +848,13 @@ static int axi_dac_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	if (ADI_AXI_PCORE_VER_MAJOR(ver) !=
> ADI_AXI_PCORE_VER_MAJOR(*expected_ver)) {
> +	if (ADI_AXI_PCORE_VER_MAJOR(ver) !=
> +		ADI_AXI_PCORE_VER_MAJOR(st->info->version)) {
>  		dev_err(&pdev->dev,
>  			"Major version mismatch. Expected %d.%.2d.%c,
> Reported %d.%.2d.%c\n",
> -			ADI_AXI_PCORE_VER_MAJOR(*expected_ver),
> -			ADI_AXI_PCORE_VER_MINOR(*expected_ver),
> -			ADI_AXI_PCORE_VER_PATCH(*expected_ver),
> +			ADI_AXI_PCORE_VER_MAJOR(st->info->version),
> +			ADI_AXI_PCORE_VER_MINOR(st->info->version),
> +			ADI_AXI_PCORE_VER_PATCH(st->info->version),
>  			ADI_AXI_PCORE_VER_MAJOR(ver),
>  			ADI_AXI_PCORE_VER_MINOR(ver),
>  			ADI_AXI_PCORE_VER_PATCH(ver));
> @@ -629,7 +880,8 @@ static int axi_dac_probe(struct platform_device *pdev)
>  		return ret;
>  
>  	mutex_init(&st->lock);
> -	ret = devm_iio_backend_register(&pdev->dev, &axi_dac_generic, st);
> +
> +	ret = devm_iio_backend_register(&pdev->dev, st->info->backend_info,
> st);
>  	if (ret)
>  		return dev_err_probe(&pdev->dev, ret,
>  				     "failed to register iio backend\n");
> @@ -642,10 +894,21 @@ static int axi_dac_probe(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static unsigned int axi_dac_9_1_b_info = ADI_AXI_PCORE_VER(9, 1, 'b');
> +static const struct axi_dac_info dac_generic = {
> +	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
> +	.backend_info = &axi_dac_generic,
> +};
> +
> +static const struct axi_dac_info dac_ad3552r = {
> +	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
> +	.backend_info = &axi_ad3552r,
> +	.bus_controller = true,

Do we still need bus_controller?

- Nuno Sá
Re: [PATCH v5 06/10] iio: dac: adi-axi-dac: extend features
Posted by Angelo Dureghello 1 month, 2 weeks ago
On 10.10.2024 15:20, Nuno Sá wrote:
> On Tue, 2024-10-08 at 17:43 +0200, Angelo Dureghello wrote:
> > From: Angelo Dureghello <adureghello@baylibre.com>
> > 
> > Extend AXI-DAC backend with new features required to interface
> > to the ad3552r DAC. Mainly, a new compatible string is added to
> > support the ad3552r-axi DAC IP, very similar to the generic DAC
> > IP but with some customizations to work with the ad3552r.
> > 
> > Then, a serie of generic functions has been added to match with
> > ad3552r needs. Function names has been kept generic as much as
> > possible, to allow re-utilization from other frontend drivers.
> > 
> > Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
> > ---
> 
> Just some minor stuff. Not seeing any fundamental issue with this patch.
> 
> >  drivers/iio/dac/adi-axi-dac.c | 285 ++++++++++++++++++++++++++++++++++++++++-
> > -
> >  1 file changed, 274 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
> > index 04193a98616e..e43d0ecccb50 100644
> > --- a/drivers/iio/dac/adi-axi-dac.c
> > +++ b/drivers/iio/dac/adi-axi-dac.c
> > @@ -46,9 +46,28 @@
> >  #define AXI_DAC_CNTRL_1_REG			0x0044
> >  #define   AXI_DAC_CNTRL_1_SYNC			BIT(0)
> >  #define AXI_DAC_CNTRL_2_REG			0x0048
> > +#define   AXI_DAC_CNTRL_2_SDR_DDR_N		BIT(16)
> > +#define   AXI_DAC_CNTRL_2_SYMB_8B		BIT(14)
> >  #define   ADI_DAC_CNTRL_2_R1_MODE		BIT(5)
> > +#define   AXI_DAC_CNTRL_2_UNSIGNED_DATA		BIT(4)
> > +#define AXI_DAC_STATUS_1_REG			0x0054
> > +#define AXI_DAC_STATUS_2_REG			0x0058
> >  #define AXI_DAC_DRP_STATUS_REG			0x0074
> >  #define   AXI_DAC_DRP_STATUS_DRP_LOCKED		BIT(17)
> > +#define AXI_DAC_CUSTOM_RD_REG			0x0080
> > +#define AXI_DAC_CUSTOM_WR_REG			0x0084
> > +#define   AXI_DAC_CUSTOM_WR_DATA_8		GENMASK(23, 16)
> > +#define   AXI_DAC_CUSTOM_WR_DATA_16		GENMASK(23, 8)
> > +#define AXI_DAC_UI_STATUS_REG			0x0088
> > +#define   AXI_DAC_UI_STATUS_IF_BUSY		BIT(4)
> > +#define AXI_DAC_CUSTOM_CTRL_REG			0x008C
> > +#define   AXI_DAC_CUSTOM_CTRL_ADDRESS		GENMASK(31, 24)
> > +#define   AXI_DAC_CUSTOM_CTRL_SYNCED_TRANSFER	BIT(2)
> > +#define   AXI_DAC_CUSTOM_CTRL_STREAM		BIT(1)
> > +#define   AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA	BIT(0)
> > +
> > +#define
> > AXI_DAC_STREAM_ENABLE			(AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA | \
> > +						AXI_DAC_CUSTOM_CTRL_STREAM)
> >  
> >  /* DAC Channel controls */
> >  #define AXI_DAC_CHAN_CNTRL_1_REG(c)		(0x0400 + (c) * 0x40)
> > @@ -63,12 +82,27 @@
> >  #define AXI_DAC_CHAN_CNTRL_7_REG(c)		(0x0418 + (c) * 0x40)
> >  #define   AXI_DAC_CHAN_CNTRL_7_DATA_SEL		GENMASK(3, 0)
> >  
> > +#define AXI_DAC_RD_ADDR(x)			(BIT(7) | (x))
> > +
> >  /* 360 degrees in rad */
> >  #define AXI_DAC_2_PI_MEGA			6283190
> >  
> >  enum {
> >  	AXI_DAC_DATA_INTERNAL_TONE,
> >  	AXI_DAC_DATA_DMA = 2,
> > +	AXI_DAC_DATA_INTERNAL_RAMP_16BIT = 11,
> > +};
> > +
> > +enum {
> > +	AXI_DAC_BUS_TYPE_NONE,
> > +	AXI_DAC_BUS_TYPE_DDR_QSPI,
> > +};
> 
> Do we still need the above?
> 
> > +
> > +struct axi_dac_info {
> > +	unsigned int version;
> > +	const struct iio_backend_info *backend_info;
> > +	bool bus_controller;
> > +	bool has_dac_clk;
> >  };
> > 
> >  struct axi_dac_state {
> > @@ -79,9 +113,12 @@ struct axi_dac_state {
> >  	 * data/variables.
> >  	 */
> >  	struct mutex lock;
> > +	const struct axi_dac_info *info;
> > +	struct clk *clk;
> 
> Is it used?
> 
> >  	u64 dac_clk;
> >  	u32 reg_config;
> >  	bool int_tone;
> > +	int dac_clk_rate;
> >  };
> >  
> >  static int axi_dac_enable(struct iio_backend *back)
> > @@ -471,6 +508,11 @@ static int axi_dac_data_source_set(struct iio_backend
> > *back, unsigned int chan,
> >  					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
> >  					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
> >  					  AXI_DAC_DATA_DMA);
> > +	case IIO_BACKEND_INTERNAL_RAMP_16BIT:
> > +		return regmap_update_bits(st->regmap,
> > +					  AXI_DAC_CHAN_CNTRL_7_REG(chan),
> > +					  AXI_DAC_CHAN_CNTRL_7_DATA_SEL,
> > +					  AXI_DAC_DATA_INTERNAL_RAMP_16BIT);
> >  	default:
> >  		return -EINVAL;
> >  	}
> > @@ -528,6 +570,186 @@ static int axi_dac_reg_access(struct iio_backend *back,
> > unsigned int reg,
> >  	return regmap_write(st->regmap, reg, writeval);
> >  }
> >  
> > +static int axi_dac_ddr_enable(struct iio_backend *back)
> > +{
> > +	struct axi_dac_state *st = iio_backend_get_priv(back);
> > +
> > +	return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> > +				 AXI_DAC_CNTRL_2_SDR_DDR_N);
> > +}
> > +
> > +static int axi_dac_ddr_disable(struct iio_backend *back)
> > +{
> > +	struct axi_dac_state *st = iio_backend_get_priv(back);
> > +
> > +	return regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> > +			       AXI_DAC_CNTRL_2_SDR_DDR_N);
> > +}
> > +
> > +static int axi_dac_data_stream_enable(struct iio_backend *back)
> > +{
> > +	struct axi_dac_state *st = iio_backend_get_priv(back);
> > +
> > +	return regmap_set_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> > +			       AXI_DAC_STREAM_ENABLE);
> > +}
> > +
> > +static int axi_dac_data_stream_disable(struct iio_backend *back)
> > +{
> > +	struct axi_dac_state *st = iio_backend_get_priv(back);
> > +
> > +	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> > +				 AXI_DAC_STREAM_ENABLE);
> > +}
> > +
> > +static int axi_dac_data_transfer_addr(struct iio_backend *back, u32 address)
> > +{
> > +	struct axi_dac_state *st = iio_backend_get_priv(back);
> > +
> 
> We could add some validation for address with FIELD_MAX()
> 
> > +	/*
> > +	 * Sample register address, when the DAC is configured, or stream
> > +	 * start address when the FSM is in stream state.
> > +	 */
> > +	return regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> > +				  AXI_DAC_CUSTOM_CTRL_ADDRESS,
> > +				  FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS,
> > +				  address));
> > +}
> > +
> > +static int axi_dac_data_format_set(struct iio_backend *back, unsigned int ch,
> > +				   const struct iio_backend_data_fmt *data)
> > +{
> > +	struct axi_dac_state *st = iio_backend_get_priv(back);
> > +	int err;
> > 
> 
> Not sure if I mentioned it already but please use 'ret' so it's consistent with
> what we have. But for this function, see below
> 
> > +	switch (data->type) {
> > +	case IIO_BACKEND_DATA_UNSIGNED:
> > +		err = regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> > +					AXI_DAC_CNTRL_2_UNSIGNED_DATA);
> > +		if (err)
> > +			return err;
> > +		break;
> 		return regmap_clear_bits();
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +
> > +	return 0;
> 
> remove the above...
> 
> > +}
> > +
> > +static int axi_dac_read_raw(struct iio_backend *back,
> > +			    struct iio_chan_spec const *chan,
> > +			    int *val, int *val2, long mask)
> > +{
> > +	struct axi_dac_state *st = iio_backend_get_priv(back);
> > +	int err;
> > +
> > +	switch (mask) {
> > +	case IIO_CHAN_INFO_FREQUENCY: {
> > +		int reg;
> 
> I would just declare it at top scope and remove {}. Otherwise...
> > +
> > +		if (!st->info->has_dac_clk)
> > +			return -EOPNOTSUPP;
> > +
> > +		/*
> > +		 * As from ad3552r AXI IP documentation,
> > +		 * returning the SCLK depending on the stream mode.
> > +		 */
> > +		err = regmap_read(st->regmap, AXI_DAC_CUSTOM_CTRL_REG, &reg);
> > +		if (err)
> > +			return err;
> > +
> > +		if (reg & AXI_DAC_CUSTOM_CTRL_STREAM)
> > +			*val = st->dac_clk_rate / 2;
> > +		else
> > +			*val = st->dac_clk_rate / 8;
> > +
> > +		return IIO_VAL_INT;
> > +		}
> 
> ... does not look good
>  
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +}
> > +
> > +static int axi_dac_bus_reg_write(struct iio_backend *back, u32 reg, u32 val,
> > +				 size_t data_size)
> > +{
> > +	struct axi_dac_state *st = iio_backend_get_priv(back);
> > +	int ret;
> > +	u32 ival;
> > +
> > +	if (data_size == 2)
> 
> nit: sizeof(u16)
> 
> > +		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_16, val);
> > +	else
> > +		ival = FIELD_PREP(AXI_DAC_CUSTOM_WR_DATA_8, val);
> > +
> > +	ret = regmap_write(st->regmap, AXI_DAC_CUSTOM_WR_REG, ival);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/*
> > +	 * Both REG_CNTRL_2 and AXI_DAC_CNTRL_DATA_WR need to know
> > +	 * the data size. So keeping data size control here only,
> > +	 * since data size is mandatory for the current transfer.
> > +	 * DDR state handled separately by specific backend calls,
> > +	 * generally all raw register writes are SDR.
> > +	 */
> > +	if (data_size == 1)
> > +		ret = regmap_set_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> > +				      AXI_DAC_CNTRL_2_SYMB_8B);
> > +	else
> > +		ret = regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
> > +					AXI_DAC_CNTRL_2_SYMB_8B);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> > +				 AXI_DAC_CUSTOM_CTRL_ADDRESS,
> > +				 FIELD_PREP(AXI_DAC_CUSTOM_CTRL_ADDRESS,
> > reg));
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> > +				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA,
> > +				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = regmap_read_poll_timeout(st->regmap,
> > +				       AXI_DAC_CUSTOM_CTRL_REG, ival,
> > +				       ival &
> > AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA,
> > +				       10, 100 * KILO);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return regmap_clear_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
> > +				 AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA);
> > +}
> > +
> > +static int axi_dac_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val,
> > +				size_t data_size)
> > +{
> > +	struct axi_dac_state *st = iio_backend_get_priv(back);
> > +	int ret;
> > +	u32 ival;
> > +
> > +	/*
> > +	 * SPI, we write with read flag, then we read just at the AXI
> > +	 * io address space to get data read.
> > +	 */
> > +	ret = axi_dac_bus_reg_write(back, AXI_DAC_RD_ADDR(reg), 0,
> > data_size);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = regmap_read_poll_timeout(st->regmap, AXI_DAC_UI_STATUS_REG,
> > ival,
> > +				FIELD_GET(AXI_DAC_UI_STATUS_IF_BUSY, ival) !=
> > +				AXI_DAC_UI_STATUS_IF_BUSY,
> > +				10, 100);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return regmap_read(st->regmap, AXI_DAC_CUSTOM_RD_REG, val);
> > +}
> > +
> >  static const struct iio_backend_ops axi_dac_generic_ops = {
> >  	.enable = axi_dac_enable,
> >  	.disable = axi_dac_disable,
> > @@ -541,11 +763,29 @@ static const struct iio_backend_ops axi_dac_generic_ops
> > = {
> >  	.debugfs_reg_access = iio_backend_debugfs_ptr(axi_dac_reg_access),
> >  };
> >  
> > +static const struct iio_backend_ops axi_ad3552r_ops = {
> > +	.enable = axi_dac_enable,
> > +	.read_raw = axi_dac_read_raw,
> > +	.request_buffer = axi_dac_request_buffer,
> > +	.data_source_set = axi_dac_data_source_set,
> > +	.ddr_enable = axi_dac_ddr_enable,
> > +	.ddr_disable = axi_dac_ddr_disable,
> > +	.data_stream_enable = axi_dac_data_stream_enable,
> > +	.data_stream_disable = axi_dac_data_stream_disable,
> > +	.data_format_set = axi_dac_data_format_set,
> > +	.data_transfer_addr = axi_dac_data_transfer_addr,
> > +};
> > +
> >  static const struct iio_backend_info axi_dac_generic = {
> >  	.name = "axi-dac",
> >  	.ops = &axi_dac_generic_ops,
> >  };
> >  
> > +static const struct iio_backend_info axi_ad3552r = {
> > +	.name = "axi-ad3552r",
> > +	.ops = &axi_ad3552r_ops,
> > +};
> > +
> >  static const struct regmap_config axi_dac_regmap_config = {
> >  	.val_bits = 32,
> >  	.reg_bits = 32,
> > @@ -555,7 +795,6 @@ static const struct regmap_config axi_dac_regmap_config =
> > {
> >  
> >  static int axi_dac_probe(struct platform_device *pdev)
> >  {
> > -	const unsigned int *expected_ver;
> >  	struct axi_dac_state *st;
> >  	void __iomem *base;
> >  	unsigned int ver;
> > @@ -566,15 +805,26 @@ static int axi_dac_probe(struct platform_device *pdev)
> >  	if (!st)
> >  		return -ENOMEM;
> >  
> > -	expected_ver = device_get_match_data(&pdev->dev);
> > -	if (!expected_ver)
> > +	st->info = device_get_match_data(&pdev->dev);
> > +	if (!st->info)
> >  		return -ENODEV;
> >  
> > -	clk = devm_clk_get_enabled(&pdev->dev, NULL);
> > +	clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk");
> >  	if (IS_ERR(clk))
> >  		return dev_err_probe(&pdev->dev, PTR_ERR(clk),
> >  				     "failed to get clock\n");
> >  
> > +	if (st->info->has_dac_clk) {
> > +		struct clk *dac_clk;
> > +
> > +		dac_clk = devm_clk_get_enabled(&pdev->dev, "dac_clk");
> > +		if (IS_ERR(dac_clk))
> > +			return dev_err_probe(&pdev->dev, PTR_ERR(dac_clk),
> > +					     "failed to get dac_clk
> > clock\n");
> > +
> > +		st->dac_clk_rate = clk_get_rate(dac_clk);
> > +	}
> > +
> >  	base = devm_platform_ioremap_resource(pdev, 0);
> >  	if (IS_ERR(base))
> >  		return PTR_ERR(base);
> > @@ -598,12 +848,13 @@ static int axi_dac_probe(struct platform_device *pdev)
> >  	if (ret)
> >  		return ret;
> >  
> > -	if (ADI_AXI_PCORE_VER_MAJOR(ver) !=
> > ADI_AXI_PCORE_VER_MAJOR(*expected_ver)) {
> > +	if (ADI_AXI_PCORE_VER_MAJOR(ver) !=
> > +		ADI_AXI_PCORE_VER_MAJOR(st->info->version)) {
> >  		dev_err(&pdev->dev,
> >  			"Major version mismatch. Expected %d.%.2d.%c,
> > Reported %d.%.2d.%c\n",
> > -			ADI_AXI_PCORE_VER_MAJOR(*expected_ver),
> > -			ADI_AXI_PCORE_VER_MINOR(*expected_ver),
> > -			ADI_AXI_PCORE_VER_PATCH(*expected_ver),
> > +			ADI_AXI_PCORE_VER_MAJOR(st->info->version),
> > +			ADI_AXI_PCORE_VER_MINOR(st->info->version),
> > +			ADI_AXI_PCORE_VER_PATCH(st->info->version),
> >  			ADI_AXI_PCORE_VER_MAJOR(ver),
> >  			ADI_AXI_PCORE_VER_MINOR(ver),
> >  			ADI_AXI_PCORE_VER_PATCH(ver));
> > @@ -629,7 +880,8 @@ static int axi_dac_probe(struct platform_device *pdev)
> >  		return ret;
> >  
> >  	mutex_init(&st->lock);
> > -	ret = devm_iio_backend_register(&pdev->dev, &axi_dac_generic, st);
> > +
> > +	ret = devm_iio_backend_register(&pdev->dev, st->info->backend_info,
> > st);
> >  	if (ret)
> >  		return dev_err_probe(&pdev->dev, ret,
> >  				     "failed to register iio backend\n");
> > @@ -642,10 +894,21 @@ static int axi_dac_probe(struct platform_device *pdev)
> >  	return 0;
> >  }
> >  
> > -static unsigned int axi_dac_9_1_b_info = ADI_AXI_PCORE_VER(9, 1, 'b');
> > +static const struct axi_dac_info dac_generic = {
> > +	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
> > +	.backend_info = &axi_dac_generic,
> > +};
> > +
> > +static const struct axi_dac_info dac_ad3552r = {
> > +	.version = ADI_AXI_PCORE_VER(9, 1, 'b'),
> > +	.backend_info = &axi_ad3552r,
> > +	.bus_controller = true,
> 
> Do we still need bus_controller?

actually still using it to create devices subnodes.
Will move it to the last patch.
 
> 
> - Nuno Sá
> 
> 

Regards,
  angelo