[PATCH v7 4/8] iio: dac: adi-axi-dac: extend features

Angelo Dureghello
2024-10-21T12:41:40Z

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 series 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 | 269 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 255 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
index 04193a98616e..9d6809fe7a67 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_CUSTOM_CTRL_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 +82,21 @@
#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,
+};
+
+struct axi_dac_info {
+ unsigned int version;
+ const struct iio_backend_info *backend_info;
+ bool has_dac_clk;
};

struct axi_dac_state {
@@ -79,9 +107,11 @@ struct axi_dac_state {
* data/variables.
*/
struct mutex lock;
+ const struct axi_dac_info *info;
u64 dac_clk;
u32 reg_config;
bool int_tone;
+ int dac_clk_rate;
};

static int axi_dac_enable(struct iio_backend *back)
@@ -471,6 +501,11 @@ 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 +563,166 @@ 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_CUSTOM_CTRL_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_CUSTOM_CTRL_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);
+
+ if (address > FIELD_MAX(AXI_DAC_CUSTOM_CTRL_ADDRESS))
+ return -EINVAL;
+
+ /*
+ * 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);
+
+ switch (data->type) {
+ case IIO_BACKEND_DATA_UNSIGNED:
+ return regmap_clear_bits(st->regmap, AXI_DAC_CNTRL_2_REG,
+ AXI_DAC_CNTRL_2_UNSIGNED_DATA);
+ default:
+ return -EINVAL;
+ }
+}
+
+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);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_FREQUENCY:
+
+ if (!st->info->has_dac_clk)
+ return -EOPNOTSUPP;
+
+ /*
+ * Returning here always the maximum (buffering mode)
+ * clock rate.
+ */
+ *val = st->dac_clk_rate;
+
+ 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;
+
+ /*
+ * Both AXI_DAC_CNTRL_2_REG and AXI_DAC_CUSTOM_WR_REG 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 == 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;
+
+ if (data_size == sizeof(u8))
+ 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_UI_STATUS_REG, ival,
+ FIELD_GET(AXI_DAC_UI_STATUS_IF_BUSY, ival) == 0,
+ 10, 100 * KILO);
+ if (ret == -ETIMEDOUT)
+ dev_err(st->dev, "AXI read timeout\n");
+
+ /* Cleaning always AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA */
+ 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;
+
+ /*
+ * 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;
+
+ 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 +736,31 @@ 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,
+ .disable = axi_dac_disable,
+ .read_raw = axi_dac_read_raw,
+ .request_buffer = axi_dac_request_buffer,
+ .free_buffer = axi_dac_free_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 +770,6 @@ 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;
@@ -566,14 +780,29 @@ 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, "s_axi_aclk");
+ if (IS_ERR(clk)) {
+ /* Backward compat., old fdt versions without clock-names. */
+ clk = devm_clk_get_enabled(&pdev->dev, NULL);
+ 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;

- clk = devm_clk_get_enabled(&pdev->dev, NULL);
- if (IS_ERR(clk))
- return dev_err_probe(&pdev->dev, PTR_ERR(clk),
- "failed to get clock\n");
+ 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");
+
+ /* We only care about the streaming mode rate */
+ st->dac_clk_rate = clk_get_rate(dac_clk) / 2;
+ }

base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
@@ -598,12 +827,13 @@ 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 +859,8 @@ 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 +873,20 @@ 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,
+ .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