On Fri, 6 Mar 2020 13:00:59 +0200 Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote: > From: Michael Hennerich <michael.hennerich@xxxxxxxxxx> > > The AD9467 is a 16-bit, monolithic, IF sampling analog-to-digital converter > (ADC). It is optimized for high performanceover wide bandwidths and ease of > use. The product operates at a 250 MSPS conversion rate and is designed for > wireless receivers, instrumentation, and test equipment that require a high > dynamic range. The ADC requires 1.8 V and 3.3 V power supplies and a low > voltage differential input clock for full performance operation. No > external reference or driver components are required for many applications. > Data outputs are LVDS compatible (ANSI-644 compatible) and include the > means to reduce the overall current needed for short trace distances. > > Since the chip can operate at such high sample-rates (much higher than > classical interfaces), it requires that a DMA controller be used to > interface directly to the chip and push data into memory. > Typically, the AXI ADC IP core is used to interface with it. > > Link: https://www.analog.com/media/en/technical-documentation/data-sheets/AD9467.pdf > > Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx> > Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> A few minor things but otherwise looks good to me.. > --- > drivers/iio/adc/Kconfig | 15 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/ad9467.c | 432 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 448 insertions(+) > create mode 100644 drivers/iio/adc/ad9467.c > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 445070abf376..a0796510f9d4 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -246,6 +246,21 @@ config AD799X > To compile this driver as a module, choose M here: the module will be > called ad799x. > ... > +static int ad9467_spi_read(struct spi_device *spi, unsigned int reg) > +{ > + unsigned char buf[3]; > + int ret; > + > + buf[0] = 0x80 | (reg >> 8); > + buf[1] = reg & 0xFF; > + > + ret = spi_write_then_read(spi, &buf[0], 2, &buf[2], 1); Why not split buf into send part and receive? Might make it slightly more readable for no actual cost.. > + > + if (ret < 0) > + return ret; > + > + return buf[2]; > +} ... > +static int ad9467_write_raw(struct adi_axi_adc_conv *conv, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + const struct adi_axi_adc_chip_info *info = conv->chip_info; > + struct ad9467_state *st = adi_axi_adc_conv_priv(conv); > + unsigned long r_clk; > + > + switch (mask) { > + case IIO_CHAN_INFO_SCALE: > + return ad9467_set_scale(conv, val, val2); > + case IIO_CHAN_INFO_SAMP_FREQ: > + if (!st->clk) > + return -ENODEV; > + > + if (chan->extend_name) This is a very 'odd' test. Why? > + return -ENODEV; > + > + r_clk = clk_round_rate(st->clk, val); > + if (r_clk < 0 || r_clk > info->max_rate) { > + dev_warn(&st->spi->dev, > + "Error setting ADC sample rate %ld", r_clk); > + return -EINVAL; > + } > + > + return clk_set_rate(st->clk, r_clk); > + default: > + return -EINVAL; > + } > +} > + ... > +static int ad9467_probe(struct spi_device *spi) > +{ > + const struct of_device_id *oid; > + struct adi_axi_adc_conv *conv; > + struct ad9467_state *st; > + unsigned int id; > + int ret; > + > + if (!spi->dev.of_node) { > + dev_err(&spi->dev, "DT node is null\n"); > + return -ENODEV; Silly question for you. Can this happen? We can only probe this if it is in DT and hence there must be a node to get here I think. > + } > + > + oid = of_match_node(ad9467_of_match, spi->dev.of_node); > + if (!oid) > + return -ENODEV; You only ever want the data field so you can get that directly. of_device_get_match_data > + > + conv = devm_adi_axi_adc_conv_register(&spi->dev, sizeof(*st)); > + if (IS_ERR(conv)) > + return PTR_ERR(conv); > + > + st = adi_axi_adc_conv_priv(conv); > + st->spi = spi; > + > + st->clk = devm_clk_get(&spi->dev, "adc-clk"); > + if (IS_ERR(st->clk)) > + return PTR_ERR(st->clk); > + > + ret = clk_prepare_enable(st->clk); > + if (ret < 0) > + return ret; > + > + ret = devm_add_action_or_reset(&spi->dev, ad9467_clk_disable, st); > + if (ret) > + return ret; > + > + st->pwrdown_gpio = devm_gpiod_get_optional(&spi->dev, "powerdown", > + GPIOD_OUT_LOW); > + if (IS_ERR(st->pwrdown_gpio)) > + return PTR_ERR(st->pwrdown_gpio); > + > + st->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", > + GPIOD_OUT_LOW); > + if (IS_ERR(st->reset_gpio)) > + return PTR_ERR(st->reset_gpio); > + > + if (st->reset_gpio) { > + udelay(1); > + ret = gpiod_direction_output(st->reset_gpio, 1); > + mdelay(10); > + } > + > + spi_set_drvdata(spi, st); > + > + id = (unsigned int)oid->data; > + conv->chip_info = &ad9467_chip_info_tbl[id]; > + > + id = ad9467_spi_read(spi, AN877_ADC_REG_CHIP_ID); > + if (id != conv->chip_info->id) { > + dev_err(&spi->dev, "Unrecognized CHIP_ID 0x%X\n", id); > + return -ENODEV; > + } > + > + conv->reg_access = ad9467_reg_access; > + conv->write_raw = ad9467_write_raw; > + conv->read_raw = ad9467_read_raw; > + conv->preenable_setup = ad9467_preenable_setup; > + > + return ad9467_setup(st, id); > +} > + > +static struct spi_driver ad9467_driver = { > + .driver = { > + .name = "ad9467", > + .of_match_table = ad9467_of_match, > + }, > + .probe = ad9467_probe, > +}; > +module_spi_driver(ad9467_driver); > + > +MODULE_AUTHOR("Michael Hennerich <michael.hennerich@xxxxxxxxxx>"); > +MODULE_DESCRIPTION("Analog Devices AD9467 ADC driver"); > +MODULE_LICENSE("GPL v2");
