2009-10-10 04:42:29

by Daniel Mack

[permalink] [raw]
Subject: [PATCH] drivers/misc: add driver for Texas Instruments DAC7512

This is actually too trivial to publish, but to export the function of
that chip to the userspace, a module like this is needed.

Signed-off-by: Daniel Mack <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: David Brownell <[email protected]>
Cc: [email protected]
---
drivers/misc/Kconfig | 10 ++++
drivers/misc/Makefile | 1 +
drivers/misc/ti_dac7512.c | 102 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 113 insertions(+), 0 deletions(-)
create mode 100644 drivers/misc/ti_dac7512.c

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index df1f86b..1191446 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -246,6 +246,16 @@ config EP93XX_PWM
To compile this driver as a module, choose M here: the module will
be called ep93xx_pwm.

+config TI_DAC7512
+ tristate "Texas Instruments DAC7512"
+ depends on SPI && SYSFS
+ help
+ If you say yes here you get support for the Texas Instruments
+ DAC7512 16-bit digital-to-analog converter.
+
+ This driver can also be built as a module. If so, the module
+ will be calles ti_dac7512.
+
source "drivers/misc/c2port/Kconfig"
source "drivers/misc/eeprom/Kconfig"
source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index f982d2e..d59830e 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_SGI_GRU) += sgi-gru/
obj-$(CONFIG_HP_ILO) += hpilo.o
obj-$(CONFIG_ISL29003) += isl29003.o
obj-$(CONFIG_EP93XX_PWM) += ep93xx_pwm.o
+obj-$(CONFIG_TI_DAC7512) += ti_dac7512.o
obj-$(CONFIG_C2PORT) += c2port/
obj-y += eeprom/
obj-y += cb710/
diff --git a/drivers/misc/ti_dac7512.c b/drivers/misc/ti_dac7512.c
new file mode 100644
index 0000000..3c60dcf
--- /dev/null
+++ b/drivers/misc/ti_dac7512.c
@@ -0,0 +1,102 @@
+/*
+ * dac7512.c - Linux kernel module for
+ * Texas Instruments DAC7512
+ *
+ * Copyright (c) 2009 Daniel Mack <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/spi/spi.h>
+
+#define DAC7512_DRV_NAME "dac7512"
+#define DRIVER_VERSION "1.0"
+
+static ssize_t dac7512_store_val(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ unsigned char tmp[2];
+ unsigned long val;
+
+ if (strict_strtoul(buf, 10, &val) < 0)
+ return -EINVAL;
+
+ tmp[0] = val >> 8;
+ tmp[1] = val & 0xff;
+ spi_write(spi, tmp, sizeof(tmp));
+ return count;
+}
+
+static DEVICE_ATTR(value, S_IWUSR | S_IRUGO,
+ NULL, dac7512_store_val);
+
+static struct attribute *dac7512_attributes[] = {
+ &dev_attr_value.attr,
+ NULL
+};
+
+static const struct attribute_group dac7512_attr_group = {
+ .attrs = dac7512_attributes,
+};
+
+static int __devinit dac7512_probe(struct spi_device *spi)
+{
+ int ret;
+
+ spi->bits_per_word = 8;
+ spi->mode = SPI_MODE_0;
+ ret = spi_setup(spi);
+ if (ret < 0)
+ return ret;
+
+ return sysfs_create_group(&spi->dev.kobj, &dac7512_attr_group);
+}
+
+static int __devexit dac7512_remove(struct spi_device *spi)
+{
+ sysfs_remove_group(&spi->dev.kobj, &dac7512_attr_group);
+ return 0;
+}
+
+static struct spi_driver dac7512_driver = {
+ .driver = {
+ .name = DAC7512_DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = dac7512_probe,
+ .remove = __devexit_p(dac7512_remove),
+};
+
+static int __init dac7512_init(void)
+{
+ return spi_register_driver(&dac7512_driver);
+}
+
+static void __exit dac7512_exit(void)
+{
+ spi_unregister_driver(&dac7512_driver);
+}
+
+MODULE_AUTHOR("Daniel Mack <[email protected]>");
+MODULE_DESCRIPTION("DAC7512 16-bit DAC");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(DRIVER_VERSION);
+
+module_init(dac7512_init);
+module_exit(dac7512_exit);
--
1.6.0.4


2009-10-12 16:32:27

by Hartley Sweeten

[permalink] [raw]
Subject: RE: [spi-devel-general] [PATCH] drivers/misc: add driver for TexasInstruments DAC7512

On Wednesday, October 07, 2009 1:01 PM, Daniel Mack wrote:
> This is actually too trivial to publish, but to export the function of
> that chip to the userspace, a module like this is needed.
>
> Signed-off-by: Daniel Mack <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: David Brownell <[email protected]>
> Cc: [email protected]
> ---

[snip]

> +static ssize_t dac7512_store_val(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct spi_device *spi = to_spi_device(dev);
> + unsigned char tmp[2];
> + unsigned long val;
> +
> + if (strict_strtoul(buf, 10, &val) < 0)
> + return -EINVAL;
> +
> + tmp[0] = val >> 8;
> + tmp[1] = val & 0xff;
> + spi_write(spi, tmp, sizeof(tmp));
> + return count;
> +}
> +
> +static DEVICE_ATTR(value, S_IWUSR | S_IRUGO,
> + NULL, dac7512_store_val);

You have declared the "value" device attribute with mode S_IWUSR | S_IRUGO
but have not provided a show callback.

Regards,
Hartley

2009-10-13 00:03:31

by Daniel Mack

[permalink] [raw]
Subject: Re: [spi-devel-general] [PATCH] drivers/misc: add driver for TexasInstruments DAC7512

On Mon, Oct 12, 2009 at 12:31:46PM -0400, H Hartley Sweeten wrote:
> On Wednesday, October 07, 2009 1:01 PM, Daniel Mack wrote:
> > This is actually too trivial to publish, but to export the function of
> > that chip to the userspace, a module like this is needed.
> >
> > Signed-off-by: Daniel Mack <[email protected]>
> > Cc: Andrew Morton <[email protected]>
> > Cc: David Brownell <[email protected]>
> > Cc: [email protected]
> > ---
>
> [snip]
>
> > +static ssize_t dac7512_store_val(struct device *dev,
> > + struct device_attribute *attr,
> > + const char *buf, size_t count)
> > +{
> > + struct spi_device *spi = to_spi_device(dev);
> > + unsigned char tmp[2];
> > + unsigned long val;
> > +
> > + if (strict_strtoul(buf, 10, &val) < 0)
> > + return -EINVAL;
> > +
> > + tmp[0] = val >> 8;
> > + tmp[1] = val & 0xff;
> > + spi_write(spi, tmp, sizeof(tmp));
> > + return count;
> > +}
> > +
> > +static DEVICE_ATTR(value, S_IWUSR | S_IRUGO,
> > + NULL, dac7512_store_val);
>
> You have declared the "value" device attribute with mode S_IWUSR | S_IRUGO
> but have not provided a show callback.

That's true, and acutally on purpose. I would have needed a private data
structure to allocate which I didn't do because I didn't need that. The
approach is purely write-only, especially beacuse the hardware also does
not provide a way to read back the current value.

Daniel

2009-10-13 00:20:17

by Daniel Mack

[permalink] [raw]
Subject: Re: [spi-devel-general] [PATCH] drivers/misc: add driver for TexasInstruments DAC7512

On Mon, Oct 12, 2009 at 12:31:46PM -0400, H Hartley Sweeten wrote:
> On Wednesday, October 07, 2009 1:01 PM, Daniel Mack wrote:
> > This is actually too trivial to publish, but to export the function of
> > that chip to the userspace, a module like this is needed.
> >
> > Signed-off-by: Daniel Mack <[email protected]>
> > Cc: Andrew Morton <[email protected]>
> > Cc: David Brownell <[email protected]>
> > Cc: [email protected]
> > ---
>
> [snip]
>
> > +static ssize_t dac7512_store_val(struct device *dev,
> > + struct device_attribute *attr,
> > + const char *buf, size_t count)
> > +{
> > + struct spi_device *spi = to_spi_device(dev);
> > + unsigned char tmp[2];
> > + unsigned long val;
> > +
> > + if (strict_strtoul(buf, 10, &val) < 0)
> > + return -EINVAL;
> > +
> > + tmp[0] = val >> 8;
> > + tmp[1] = val & 0xff;
> > + spi_write(spi, tmp, sizeof(tmp));
> > + return count;
> > +}
> > +
> > +static DEVICE_ATTR(value, S_IWUSR | S_IRUGO,
> > + NULL, dac7512_store_val);
>
> You have declared the "value" device attribute with mode S_IWUSR | S_IRUGO
> but have not provided a show callback.

Sorry, forget my last mail, I got you wrong. You're of course right,
S_IRUGO shouldn't be set for write-only attributes. Updates patch below.

Thanks,
Daniel

>From ab18a967e55d2bb1d39559333bca81a01c2838f0 Mon Sep 17 00:00:00 2001
From: Daniel Mack <[email protected]>
Date: Thu, 8 Oct 2009 03:55:46 +0800
Subject: [PATCH] drivers/misc: add driver for Texas Instruments DAC7512

This is actually too trivial to publish, but to export the function of
that chip to the userspace, a module like this is needed.

Signed-off-by: Daniel Mack <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: David Brownell <[email protected]>
Cc: [email protected]
---
drivers/misc/Kconfig | 10 ++++
drivers/misc/Makefile | 1 +
drivers/misc/ti_dac7512.c | 101 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 112 insertions(+), 0 deletions(-)
create mode 100644 drivers/misc/ti_dac7512.c

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index df1f86b..1191446 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -246,6 +246,16 @@ config EP93XX_PWM
To compile this driver as a module, choose M here: the module will
be called ep93xx_pwm.

+config TI_DAC7512
+ tristate "Texas Instruments DAC7512"
+ depends on SPI && SYSFS
+ help
+ If you say yes here you get support for the Texas Instruments
+ DAC7512 16-bit digital-to-analog converter.
+
+ This driver can also be built as a module. If so, the module
+ will be calles ti_dac7512.
+
source "drivers/misc/c2port/Kconfig"
source "drivers/misc/eeprom/Kconfig"
source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index f982d2e..d59830e 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_SGI_GRU) += sgi-gru/
obj-$(CONFIG_HP_ILO) += hpilo.o
obj-$(CONFIG_ISL29003) += isl29003.o
obj-$(CONFIG_EP93XX_PWM) += ep93xx_pwm.o
+obj-$(CONFIG_TI_DAC7512) += ti_dac7512.o
obj-$(CONFIG_C2PORT) += c2port/
obj-y += eeprom/
obj-y += cb710/
diff --git a/drivers/misc/ti_dac7512.c b/drivers/misc/ti_dac7512.c
new file mode 100644
index 0000000..d3f229a
--- /dev/null
+++ b/drivers/misc/ti_dac7512.c
@@ -0,0 +1,101 @@
+/*
+ * dac7512.c - Linux kernel module for
+ * Texas Instruments DAC7512
+ *
+ * Copyright (c) 2009 Daniel Mack <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/spi/spi.h>
+
+#define DAC7512_DRV_NAME "dac7512"
+#define DRIVER_VERSION "1.0"
+
+static ssize_t dac7512_store_val(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ unsigned char tmp[2];
+ unsigned long val;
+
+ if (strict_strtoul(buf, 10, &val) < 0)
+ return -EINVAL;
+
+ tmp[0] = val >> 8;
+ tmp[1] = val & 0xff;
+ spi_write(spi, tmp, sizeof(tmp));
+ return count;
+}
+
+static DEVICE_ATTR(value, S_IWUSR, NULL, dac7512_store_val);
+
+static struct attribute *dac7512_attributes[] = {
+ &dev_attr_value.attr,
+ NULL
+};
+
+static const struct attribute_group dac7512_attr_group = {
+ .attrs = dac7512_attributes,
+};
+
+static int __devinit dac7512_probe(struct spi_device *spi)
+{
+ int ret;
+
+ spi->bits_per_word = 8;
+ spi->mode = SPI_MODE_0;
+ ret = spi_setup(spi);
+ if (ret < 0)
+ return ret;
+
+ return sysfs_create_group(&spi->dev.kobj, &dac7512_attr_group);
+}
+
+static int __devexit dac7512_remove(struct spi_device *spi)
+{
+ sysfs_remove_group(&spi->dev.kobj, &dac7512_attr_group);
+ return 0;
+}
+
+static struct spi_driver dac7512_driver = {
+ .driver = {
+ .name = DAC7512_DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = dac7512_probe,
+ .remove = __devexit_p(dac7512_remove),
+};
+
+static int __init dac7512_init(void)
+{
+ return spi_register_driver(&dac7512_driver);
+}
+
+static void __exit dac7512_exit(void)
+{
+ spi_unregister_driver(&dac7512_driver);
+}
+
+MODULE_AUTHOR("Daniel Mack <[email protected]>");
+MODULE_DESCRIPTION("DAC7512 16-bit DAC");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(DRIVER_VERSION);
+
+module_init(dac7512_init);
+module_exit(dac7512_exit);
--
1.6.0.4