--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Analog Devices Generic AXI DAC IP core
+ * Link: https://wiki.analog.com/resources/fpga/docs/axi_dac_ip
+ *
+ * Copyright 2016-2024 Analog Devices Inc.
+ */
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/limits.h>
+#include <linux/kstrtox.h>
+#include <linux/math.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/units.h>
+
+#include <linux/fpga/adi-axi-common.h>
+#include <linux/iio/backend.h>
+#include <linux/iio/buffer-dmaengine.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+
+/*
+ * Register definitions:
+ * https://wiki.analog.com/resources/fpga/docs/axi_dac_ip#register_map
+ */
+
+/* Base controls */
+#define AXI_DAC_REG_CONFIG 0x0c
+#define AXI_DDS_DISABLE BIT(6)
+
+ /* DAC controls */
+#define AXI_DAC_REG_RSTN 0x0040
+#define AXI_DAC_RSTN_CE_N BIT(2)
+#define AXI_DAC_RSTN_MMCM_RSTN BIT(1)
+#define AXI_DAC_RSTN_RSTN BIT(0)
+#define AXI_DAC_REG_CNTRL_1 0x0044
+#define AXI_DAC_SYNC BIT(0)
+#define AXI_DAC_REG_CNTRL_2 0x0048
+#define ADI_DAC_R1_MODE BIT(4)
+#define AXI_DAC_DRP_STATUS 0x0074
+#define AXI_DAC_DRP_LOCKED BIT(17)
+/* DAC Channel controls */
+#define AXI_DAC_REG_CHAN_CNTRL_1(c) (0x0400 + (c) * 0x40)
+#define AXI_DAC_REG_CHAN_CNTRL_3(c) (0x0408 + (c) * 0x40)
+#define AXI_DAC_SCALE_SIGN BIT(15)
+#define AXI_DAC_SCALE_INT BIT(14)
+#define AXI_DAC_SCALE GENMASK(14, 0)
+#define AXI_DAC_REG_CHAN_CNTRL_2(c) (0x0404 + (c) * 0x40)
+#define AXI_DAC_REG_CHAN_CNTRL_4(c) (0x040c + (c) * 0x40)
+#define AXI_DAC_PHASE GENMASK(31, 16)
+#define AXI_DAC_FREQUENCY GENMASK(15, 0)
+#define AXI_DAC_REG_CHAN_CNTRL_7(c) (0x0418 + (c) * 0x40)
+#define AXI_DAC_DATA_SEL GENMASK(3, 0)
+
+/* 360 degrees in rad */
+#define AXI_DAC_2_PI_MEGA 6283190
+enum {
+ AXI_DAC_DATA_INTERNAL_TONE,
+ AXI_DAC_DATA_DMA = 2,
+};
+
+struct axi_dac_state {
+ struct regmap *regmap;
+ struct device *dev;
+ /*
+ * lock to protect multiple accesses to the device registers and global
+ * data/variables.
+ */
+ struct mutex lock;
+ u64 dac_clk;
+ u32 reg_config;
+ bool int_tone;
+};
+
+static int axi_dac_enable(struct iio_backend *back)
+{
+ struct axi_dac_state *st = iio_backend_get_priv(back);
+ unsigned int __val;
+ int ret;
+
+ guard(mutex)(&st->lock);
+ ret = regmap_set_bits(st->regmap, AXI_DAC_REG_RSTN,
+ AXI_DAC_RSTN_MMCM_RSTN);
+ if (ret)
+ return ret;
+ /*
+ * Make sure the DRP (Dynamic Reconfiguration Port) is locked. Not all
+ * designs really use it but if they don't we still get the lock bit
+ * set. So let's do it all the time so the code is generic.
+ */
+ ret = regmap_read_poll_timeout(st->regmap, AXI_DAC_DRP_STATUS, __val,
+ __val & AXI_DAC_DRP_LOCKED, 100, 1000);
+ if (ret)
+ return ret;
+
+ return regmap_set_bits(st->regmap, AXI_DAC_REG_RSTN,
+ AXI_DAC_RSTN_RSTN | AXI_DAC_RSTN_MMCM_RSTN);
+}
+
+static void axi_dac_disable(struct iio_backend *back)
+{
+ struct axi_dac_state *st = iio_backend_get_priv(back);
+
+ guard(mutex)(&st->lock);
+ regmap_write(st->regmap, AXI_DAC_REG_RSTN, 0);
+}
+
+static struct iio_buffer *axi_dac_request_buffer(struct iio_backend *back,
+ struct iio_dev *indio_dev)
+{
+ struct axi_dac_state *st = iio_backend_get_priv(back);
+ const char *dma_name;
+
+ if (device_property_read_string(st->dev, "dma-names", &dma_name))
+ dma_name = "tx";
+
+ return iio_dmaengine_buffer_setup_ext(st->dev, indio_dev, dma_name,
+ IIO_BUFFER_DIRECTION_OUT);
+}
+
+static void axi_dac_free_buffer(struct iio_backend *back,
+ struct iio_buffer *buffer)
+{
+ iio_dmaengine_buffer_free(buffer);
+}
+
+enum {
+ AXI_DAC_FREQ_TONE_1,
+ AXI_DAC_FREQ_TONE_2,
+ AXI_DAC_SCALE_TONE_1,
+ AXI_DAC_SCALE_TONE_2,
+ AXI_DAC_PHASE_TONE_1,
+ AXI_DAC_PHASE_TONE_2,
+};
+
+static int __axi_dac_frequency_get(struct axi_dac_state *st, unsigned int chan,
+ unsigned int tone_2, unsigned int *freq)
+{
+ u32 reg, raw;
+ int ret;
+
+ if (!st->dac_clk) {
+ dev_err(st->dev, "Sampling rate is 0...\n");
+ return -EINVAL;
+ }
+
+ if (tone_2)
+ reg = AXI_DAC_REG_CHAN_CNTRL_4(chan);
+ else
+ reg = AXI_DAC_REG_CHAN_CNTRL_2(chan);
+
+ ret = regmap_read(st->regmap, reg, &raw);
+ if (ret)
+ return ret;
+
+ raw = FIELD_GET(AXI_DAC_FREQUENCY, raw);
+ *freq = DIV_ROUND_CLOSEST_ULL(raw * st->dac_clk, BIT(16));
+
+ return 0;
+}
+
+static int axi_dac_frequency_get(struct axi_dac_state *st,
+ const struct iio_chan_spec *chan, char *buf,
+ unsigned int tone_2)
+{
+ unsigned int freq;
+ int ret;
+
+ scoped_guard(mutex, &st->lock) {
+ ret = __axi_dac_frequency_get(st, chan->channel, tone_2, &freq);
+ if (ret)
+ return ret;
+ }
+
+ return sysfs_emit(buf, "%u\n", freq);
+}
+
+static int axi_dac_scale_get(struct axi_dac_state *st,
+ const struct iio_chan_spec *chan, char *buf,
+ unsigned int tone_2)
+{
+ unsigned int scale, sign;
+ int ret, vals[2];
+ u32 reg, raw;
+
+ if (tone_2)
+ reg = AXI_DAC_REG_CHAN_CNTRL_3(chan->channel);
+ else
+ reg = AXI_DAC_REG_CHAN_CNTRL_1(chan->channel);
+
+ ret = regmap_read(st->regmap, reg, &raw);
+ if (ret)
+ return ret;
+
+ sign = FIELD_GET(AXI_DAC_SCALE_SIGN, raw);
+ raw = FIELD_GET(AXI_DAC_SCALE, raw);
+ scale = DIV_ROUND_CLOSEST_ULL((u64)raw * MEGA, AXI_DAC_SCALE_INT);
+
+ vals[0] = scale / MEGA;
+ vals[1] = scale % MEGA;
+
+ if (sign) {
+ vals[0] *= -1;
+ if (!vals[0])
+ vals[1] *= -1;
+ }
+
+ return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, ARRAY_SIZE(vals),
+ vals);
+}
+
+static int axi_dac_phase_get(struct axi_dac_state *st,
+ const struct iio_chan_spec *chan, char *buf,
+ unsigned int tone_2)
+{
+ u32 reg, raw, phase;
+ int ret, vals[2];
+
+ if (tone_2)
+ reg = AXI_DAC_REG_CHAN_CNTRL_4(chan->channel);
+ else
+ reg = AXI_DAC_REG_CHAN_CNTRL_2(chan->channel);
+
+ ret = regmap_read(st->regmap, reg, &raw);
+ if (ret)
+ return ret;
+
+ raw = FIELD_GET(AXI_DAC_PHASE, raw);
+ phase = DIV_ROUND_CLOSEST_ULL((u64)raw * AXI_DAC_2_PI_MEGA, U16_MAX);
+
+ vals[0] = phase / MEGA;
+ vals[1] = phase % MEGA;
+
+ return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, ARRAY_SIZE(vals),
+ vals);
+}
+
+static int __axi_dac_frequency_set(struct axi_dac_state *st, unsigned int chan,
+ u64 sample_rate, unsigned int freq,
+ unsigned int tone_2)
+{
+ u32 reg;
+ u16 raw;
+ int ret;
+
+ if (!sample_rate || freq > sample_rate / 2) {
+ dev_err(st->dev, "Invalid frequency(%u) dac_clk(%llu)\n",
+ freq, sample_rate);
+ return -EINVAL;
+ }
+
+ if (tone_2)
+ reg = AXI_DAC_REG_CHAN_CNTRL_4(chan);
+ else
+ reg = AXI_DAC_REG_CHAN_CNTRL_2(chan);
+
+ raw = DIV64_U64_ROUND_CLOSEST((u64)freq * BIT(16), sample_rate);
+
+ ret = regmap_update_bits(st->regmap, reg, AXI_DAC_FREQUENCY, raw);
+ if (ret)
+ return ret;
+
+ /* synchronize channels */
+ return regmap_set_bits(st->regmap, AXI_DAC_REG_CNTRL_1, AXI_DAC_SYNC);
+}
+
+static int axi_dac_frequency_set(struct axi_dac_state *st,
+ const struct iio_chan_spec *chan,
+ const char *buf, size_t len, unsigned int tone_2)
+{
+ unsigned int freq;
+ int ret;
+
+ ret = kstrtou32(buf, 10, &freq);
+ if (ret)
+ return ret;
+
+ guard(mutex)(&st->lock);
+ ret = __axi_dac_frequency_set(st, chan->channel, st->dac_clk, freq,
+ tone_2);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+static int axi_dac_scale_set(struct axi_dac_state *st,
+ const struct iio_chan_spec *chan,
+ const char *buf, size_t len, unsigned int tone_2)
+{
+ int integer, frac, scale;
+ u32 raw = 0, reg;
+ int ret;
+
+ ret = iio_str_to_fixpoint(buf, 100000, &integer, &frac);
+ if (ret)
+ return ret;
+
+ scale = integer * MEGA + frac;
+ if (scale <= -2 * (int)MEGA || scale >= 2 * (int)MEGA)
+ return -EINVAL;
+
+ /* format is 1.1.14 (sign, integer and fractional bits) */
+ if (scale < 0) {
+ raw = FIELD_PREP(AXI_DAC_SCALE_SIGN, 1);
+ scale *= -1;
+ }
+
+ raw |= div_u64((u64)scale * AXI_DAC_SCALE_INT, MEGA);
+
+ if (tone_2)
+ reg = AXI_DAC_REG_CHAN_CNTRL_3(chan->channel);
+ else
+ reg = AXI_DAC_REG_CHAN_CNTRL_1(chan->channel);
+
+ guard(mutex)(&st->lock);
+ ret = regmap_write(st->regmap, reg, raw);
+ if (ret)
+ return ret;
+
+ /* synchronize channels */
+ ret = regmap_set_bits(st->regmap, AXI_DAC_REG_CNTRL_1, AXI_DAC_SYNC);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+static int axi_dac_phase_set(struct axi_dac_state *st,
+ const struct iio_chan_spec *chan,
+ const char *buf, size_t len, unsigned int tone_2)
+{
+ int integer, frac, phase;
+ u32 raw, reg;
+ int ret;
+
+ ret = iio_str_to_fixpoint(buf, 100000, &integer, &frac);
+ if (ret)
+ return ret;
+
+ phase = integer * MEGA + frac;
+ if (phase < 0 || phase > AXI_DAC_2_PI_MEGA)
+ return -EINVAL;
+
+ raw = DIV_ROUND_CLOSEST_ULL((u64)phase * U16_MAX, AXI_DAC_2_PI_MEGA);
+
+ if (tone_2)
+ reg = AXI_DAC_REG_CHAN_CNTRL_4(chan->channel);
+ else
+ reg = AXI_DAC_REG_CHAN_CNTRL_2(chan->channel);
+
+ guard(mutex)(&st->lock);
+ ret = regmap_update_bits(st->regmap, reg, AXI_DAC_PHASE,
+ FIELD_PREP(AXI_DAC_PHASE, raw));
+ if (ret)
+ return ret;
+
+ /* synchronize channels */
+ ret = regmap_set_bits(st->regmap, AXI_DAC_REG_CNTRL_1, AXI_DAC_SYNC);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+static int axi_dac_ext_info_set(struct iio_backend *back, uintptr_t private,
+ const struct iio_chan_spec *chan,
+ const char *buf, size_t len)
+{
+ struct axi_dac_state *st = iio_backend_get_priv(back);
+
+ switch (private) {
+ case AXI_DAC_FREQ_TONE_1:
+ case AXI_DAC_FREQ_TONE_2:
+ return axi_dac_frequency_set(st, chan, buf, len,
+ private - AXI_DAC_FREQ_TONE_1);
+ case AXI_DAC_SCALE_TONE_1:
+ case AXI_DAC_SCALE_TONE_2:
+ return axi_dac_scale_set(st, chan, buf, len,
+ private - AXI_DAC_SCALE_TONE_1);
+ case AXI_DAC_PHASE_TONE_1:
+ case AXI_DAC_PHASE_TONE_2:
+ return axi_dac_phase_set(st, chan, buf, len,
+ private - AXI_DAC_PHASE_TONE_2);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int axi_dac_ext_info_get(struct iio_backend *back, uintptr_t private,
+ const struct iio_chan_spec *chan, char *buf)
+{
+ struct axi_dac_state *st = iio_backend_get_priv(back);
+
+ switch (private) {
+ case AXI_DAC_FREQ_TONE_1:
+ case AXI_DAC_FREQ_TONE_2:
+ return axi_dac_frequency_get(st, chan, buf,
+ private - AXI_DAC_FREQ_TONE_1);
+ case AXI_DAC_SCALE_TONE_1:
+ case AXI_DAC_SCALE_TONE_2:
+ return axi_dac_scale_get(st, chan, buf,
+ private - AXI_DAC_SCALE_TONE_1);
+ case AXI_DAC_PHASE_TONE_1:
+ case AXI_DAC_PHASE_TONE_2:
+ return axi_dac_phase_get(st, chan, buf,
+ private - AXI_DAC_PHASE_TONE_1);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static const struct iio_chan_spec_ext_info axi_dac_ext_info[] = {
+ IIO_BACKEND_EX_INFO("frequency0", IIO_SEPARATE, AXI_DAC_FREQ_TONE_1),
+ IIO_BACKEND_EX_INFO("frequency1", IIO_SEPARATE, AXI_DAC_FREQ_TONE_2),
+ IIO_BACKEND_EX_INFO("scale0", IIO_SEPARATE, AXI_DAC_SCALE_TONE_1),
+ IIO_BACKEND_EX_INFO("scale1", IIO_SEPARATE, AXI_DAC_SCALE_TONE_2),
+ IIO_BACKEND_EX_INFO("phase0", IIO_SEPARATE, AXI_DAC_PHASE_TONE_1),
+ IIO_BACKEND_EX_INFO("phase1", IIO_SEPARATE, AXI_DAC_PHASE_TONE_2),
+ {}
+};
+
+static int axi_dac_extend_chan(struct iio_backend *back,
+ struct iio_chan_spec *chan)
+{
+ struct axi_dac_state *st = iio_backend_get_priv(back);
+
+ if (chan->type != IIO_ALTVOLTAGE)
+ return -EINVAL;
+ if (st->reg_config & AXI_DDS_DISABLE)
+ /* nothing to extend */
+ return 0;
+
+ chan->ext_info = axi_dac_ext_info;
+
+ return 0;
+}
+
+static int axi_dac_data_source_set(struct iio_backend *back, unsigned int chan,
+ enum iio_backend_data_source data)
+{
+ struct axi_dac_state *st = iio_backend_get_priv(back);
+
+ switch (data) {
+ case IIO_BACKEND_INTERNAL_CONTINUOS_WAVE:
+ return regmap_update_bits(st->regmap,
+ AXI_DAC_REG_CHAN_CNTRL_7(chan),
+ AXI_DAC_DATA_SEL,
+ AXI_DAC_DATA_INTERNAL_TONE);
+ case IIO_BACKEND_EXTERNAL:
+ return regmap_update_bits(st->regmap,
+ AXI_DAC_REG_CHAN_CNTRL_7(chan),
+ AXI_DAC_DATA_SEL, AXI_DAC_DATA_DMA);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int axi_dac_set_sample_rate(struct iio_backend *back, unsigned int chan,
+ u64 sample_rate)
+{
+ struct axi_dac_state *st = iio_backend_get_priv(back);
+ unsigned int freq;
+ int ret, tone;
+
+ if (!sample_rate)
+ return -EINVAL;
+ if (st->reg_config & AXI_DDS_DISABLE)
+ /* sample_rate has no meaning if DDS is disabled */
+ return 0;
+
+ guard(mutex)(&st->lock);
+ /*
+ * If dac_clk is 0 then this must be the first time we're being notified
+ * about the interface sample rate. Hence, just update our internal
+ * variable and bail... If it's not 0, then we get the current DDS
+ * frequency (for the old rate) and update the registers for the new
+ * sample rate.
+ */
+ if (!st->dac_clk) {
+ st->dac_clk = sample_rate;
+ return 0;
+ }
+
+ for (tone = 0; tone <= AXI_DAC_FREQ_TONE_2; tone++) {
+ ret = __axi_dac_frequency_get(st, chan, tone, &freq);
+ if (ret)
+ return ret;
+
+ ret = __axi_dac_frequency_set(st, chan, sample_rate, tone, freq);
+ if (ret)
+ return ret;
+ }
+
+ st->dac_clk = sample_rate;
+
+ return 0;
+}
+
+static const struct iio_backend_ops axi_dac_generic = {
+ .enable = axi_dac_enable,
+ .disable = axi_dac_disable,
+ .request_buffer = axi_dac_request_buffer,
+ .free_buffer = axi_dac_free_buffer,
+ .extend_chan_spec = axi_dac_extend_chan,
+ .ext_info_set = axi_dac_ext_info_set,
+ .ext_info_get = axi_dac_ext_info_get,
+ .data_source_set = axi_dac_data_source_set,
+ .set_sample_rate = axi_dac_set_sample_rate,
+};
+
+static const struct regmap_config axi_dac_regmap_config = {
+ .val_bits = 32,
+ .reg_bits = 32,
+ .reg_stride = 4,
+ .max_register = 0x0800,
+};
+
+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;
+ struct clk *clk;
+ int ret;
+
+ st = devm_kzalloc(&pdev->dev, sizeof(*st), GFP_KERNEL);
+ if (!st)
+ return -ENOMEM;
+
+ expected_ver = device_get_match_data(&pdev->dev);
+ if (!expected_ver)
+ return -ENODEV;
+
+ clk = devm_clk_get_enabled(&pdev->dev, NULL);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ st->dev = &pdev->dev;
+ st->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+ &axi_dac_regmap_config);
+ if (IS_ERR(st->regmap))
+ return PTR_ERR(st->regmap);
+
+ /*
+ * Force disable the core. Up to the frontend to enable us. And we can
+ * still read/write registers...
+ */
+ ret = regmap_write(st->regmap, AXI_DAC_REG_RSTN, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(st->regmap, ADI_AXI_REG_VERSION, &ver);
+ if (ret)
+ return ret;
+
+ if (ADI_AXI_PCORE_VER_MAJOR(ver) != ADI_AXI_PCORE_VER_MAJOR(*expected_ver)) {
+ 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(ver),
+ ADI_AXI_PCORE_VER_MINOR(ver),
+ ADI_AXI_PCORE_VER_PATCH(ver));
+ return -ENODEV;
+ }
+
+ /* Let's get the core read only configuration */
+ ret = regmap_read(st->regmap, AXI_DAC_REG_CONFIG, &st->reg_config);
+ if (ret)
+ return ret;
+
+ /*
+ * In some designs, setting the R1_MODE bit to 0 (which is the default
+ * value) causes all channels of the frontend to be routed to the same
+ * DMA (so they are sampled together). This is for things like
+ * Multiple-Input and Multiple-Output (MIMO). As most of the times we
+ * want independent channels let's override the core's default value and
+ * set the R1_MODE bit.
+ */
+ ret = regmap_set_bits(st->regmap, AXI_DAC_REG_CNTRL_2, ADI_DAC_R1_MODE);
+ if (ret)
+ return ret;
+
+ mutex_init(&st->lock);
+ ret = devm_iio_backend_register(&pdev->dev, &axi_dac_generic, st);
+ if (ret)
+ return ret;
+
+ dev_info(&pdev->dev, "AXI DAC IP core (%d.%.2d.%c) probed\n",
+ ADI_AXI_PCORE_VER_MAJOR(ver),
+ ADI_AXI_PCORE_VER_MINOR(ver),
+ ADI_AXI_PCORE_VER_PATCH(ver));
+
+ return 0;
+}
+
+static unsigned int axi_dac_9_1_b_info = ADI_AXI_PCORE_VER(9, 1, 'b');
+
+static const struct of_device_id axi_dac_of_match[] = {
+ { .compatible = "adi,axi-dac-9.1.b", .data = &axi_dac_9_1_b_info },
+ {}
+};
+MODULE_DEVICE_TABLE(of, axi_dac_of_match);
+
+static struct platform_driver axi_dac_driver = {
+ .driver = {
+ .name = "adi-axi-dac",
+ .of_match_table = axi_dac_of_match,
+ },
+ .probe = axi_dac_probe,
+};
+module_platform_driver(axi_dac_driver);
+
+MODULE_DESCRIPTION("Analog Devices Generic AXI DAC IP core driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(IIO_DMAENGINE_BUFFER);
+MODULE_IMPORT_NS(IIO_BACKEND);
projects / J-linux.git / commitdiff