The regmap API supports IO port accessors so we can take advantage of
regmap abstractions rather than handling access to the device registers
directly in the driver.
Suggested-by: Andy Shevchenko <[email protected]>
Signed-off-by: William Breathitt Gray <[email protected]>
---
drivers/iio/dac/Kconfig | 1 +
drivers/iio/dac/cio-dac.c | 71 +++++++++++++++++++++++++++++----------
2 files changed, 54 insertions(+), 18 deletions(-)
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index d3f90cf86143..3acd9c3f388e 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -277,6 +277,7 @@ config CIO_DAC
tristate "Measurement Computing CIO-DAC IIO driver"
depends on X86 && (ISA_BUS || PC104)
select ISA_BUS_API
+ select REGMAP_MMIO
help
Say yes here to build support for the Measurement Computing CIO-DAC
analog output device family (CIO-DAC16, CIO-DAC08, PC104-DAC06). The
diff --git a/drivers/iio/dac/cio-dac.c b/drivers/iio/dac/cio-dac.c
index 791dd999cf29..13438f022f8e 100644
--- a/drivers/iio/dac/cio-dac.c
+++ b/drivers/iio/dac/cio-dac.c
@@ -6,16 +6,15 @@
* This driver supports the following Measurement Computing devices: CIO-DAC16,
* CIO-DAC06, and PC104-DAC06.
*/
-#include <linux/bitops.h>
+#include <linux/bits.h>
#include <linux/device.h>
-#include <linux/errno.h>
+#include <linux/err.h>
#include <linux/iio/iio.h>
#include <linux/iio/types.h>
-#include <linux/io.h>
-#include <linux/ioport.h>
#include <linux/isa.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/regmap.h>
#include <linux/types.h>
#define CIO_DAC_NUM_CHAN 16
@@ -35,25 +34,51 @@ static unsigned int num_cio_dac;
module_param_hw_array(base, uint, ioport, &num_cio_dac, 0);
MODULE_PARM_DESC(base, "Measurement Computing CIO-DAC base addresses");
+#define CIO_DAC_BASE 0x00
+#define CIO_DAC_CHANNEL_STRIDE 2
+
+static bool cio_dac_precious_reg(struct device *dev, unsigned int reg)
+{
+ /*
+ * All registers are considered precious; if the XFER jumper is set on
+ * the device, then no update occurs until a DAC register is read.
+ */
+ return true;
+}
+
+static const struct regmap_config cio_dac_regmap_config = {
+ .reg_bits = 16,
+ .reg_stride = 2,
+ .val_bits = 16,
+ .io_port = true,
+ .max_register = 0x1F,
+ .precious_reg = cio_dac_precious_reg,
+};
+
/**
* struct cio_dac_iio - IIO device private data structure
- * @chan_out_states: channels' output states
- * @base: base memory address of the DAC device
+ * @map: Regmap for the device
*/
struct cio_dac_iio {
- int chan_out_states[CIO_DAC_NUM_CHAN];
- u16 __iomem *base;
+ struct regmap *map;
};
static int cio_dac_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val, int *val2, long mask)
{
struct cio_dac_iio *const priv = iio_priv(indio_dev);
+ const unsigned int offset = chan->channel * CIO_DAC_CHANNEL_STRIDE;
+ int err;
+ unsigned int dac_val;
if (mask != IIO_CHAN_INFO_RAW)
return -EINVAL;
- *val = priv->chan_out_states[chan->channel];
+ err = regmap_read(priv->map, CIO_DAC_BASE + offset, &dac_val);
+ if (err)
+ return err;
+
+ *val = dac_val;
return IIO_VAL_INT;
}
@@ -62,6 +87,7 @@ static int cio_dac_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val, int val2, long mask)
{
struct cio_dac_iio *const priv = iio_priv(indio_dev);
+ const unsigned int offset = chan->channel * CIO_DAC_CHANNEL_STRIDE;
if (mask != IIO_CHAN_INFO_RAW)
return -EINVAL;
@@ -70,10 +96,7 @@ static int cio_dac_write_raw(struct iio_dev *indio_dev,
if ((unsigned int)val > 65535)
return -EINVAL;
- priv->chan_out_states[chan->channel] = val;
- iowrite16(val, priv->base + chan->channel);
-
- return 0;
+ return regmap_write(priv->map, CIO_DAC_BASE + offset, val);
}
static const struct iio_info cio_dac_info = {
@@ -92,7 +115,10 @@ static int cio_dac_probe(struct device *dev, unsigned int id)
{
struct iio_dev *indio_dev;
struct cio_dac_iio *priv;
+ void __iomem *regs;
unsigned int i;
+ unsigned int offset;
+ int err;
indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
if (!indio_dev)
@@ -105,11 +131,16 @@ static int cio_dac_probe(struct device *dev, unsigned int id)
return -EBUSY;
}
- priv = iio_priv(indio_dev);
- priv->base = devm_ioport_map(dev, base[id], CIO_DAC_EXTENT);
- if (!priv->base)
+ regs = devm_ioport_map(dev, base[id], CIO_DAC_EXTENT);
+ if (!regs)
return -ENOMEM;
+ priv = iio_priv(indio_dev);
+ priv->map = devm_regmap_init_mmio(dev, regs, &cio_dac_regmap_config);
+ if (IS_ERR(priv->map))
+ return dev_err_probe(dev, PTR_ERR(priv->map),
+ "Unable to initialize register map\n");
+
indio_dev->info = &cio_dac_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = cio_dac_channels;
@@ -117,8 +148,12 @@ static int cio_dac_probe(struct device *dev, unsigned int id)
indio_dev->name = dev_name(dev);
/* initialize DAC outputs to 0V */
- for (i = 0; i < CIO_DAC_NUM_CHAN; i++)
- iowrite16(0, priv->base + i);
+ for (i = 0; i < CIO_DAC_NUM_CHAN; i++) {
+ offset = i * CIO_DAC_CHANNEL_STRIDE;
+ err = regmap_write(priv->map, CIO_DAC_BASE + offset, 0);
+ if (err)
+ return err;
+ }
return devm_iio_device_register(dev, indio_dev);
}
base-commit: fe15c26ee26efa11741a7b632e9f23b01aca4cc6
--
2.39.2
On Sat, Mar 11, 2023 at 08:40:12AM -0500, William Breathitt Gray wrote:
> The regmap API supports IO port accessors so we can take advantage of
> regmap abstractions rather than handling access to the device registers
> directly in the driver.
>
> Suggested-by: Andy Shevchenko <[email protected]>
> Signed-off-by: William Breathitt Gray <[email protected]>
[...]
> @@ -117,8 +148,12 @@ static int cio_dac_probe(struct device *dev, unsigned int id)
> indio_dev->name = dev_name(dev);
>
> /* initialize DAC outputs to 0V */
> - for (i = 0; i < CIO_DAC_NUM_CHAN; i++)
> - iowrite16(0, priv->base + i);
> + for (i = 0; i < CIO_DAC_NUM_CHAN; i++) {
> + offset = i * CIO_DAC_CHANNEL_STRIDE;
> + err = regmap_write(priv->map, CIO_DAC_BASE + offset, 0);
> + if (err)
> + return err;
> + }
>
> return devm_iio_device_register(dev, indio_dev);
> }
As soon as I sent this I realized this last hunk is no longer necessary
because the chan_out_states array is gone so we don't need to match its
initialized state. I'll remove this block as superfluous and submit a v2
patch shortly.
William Breathitt Gray