* [PATCH v2 2/2] gpio: Add driver for SPI serializers
@ 2016-01-25 16:37 ` Andrew F. Davis
0 siblings, 0 replies; 18+ messages in thread
From: Andrew F. Davis @ 2016-01-25 16:37 UTC (permalink / raw)
To: Linus Walleij, Alexandre Courbot, Mark Brown, Rob Herring,
Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala
Cc: linux-gpio, devicetree, linux-kernel, Andrew F. Davis
Add generic parallel-in/serial-out shift register GPIO driver.
This includes SPI compatible devices like SN74165 serial-out shift
registers and the SN65HVS88x series of industrial serializers that can
be read over the SPI bus and used for GPI (General Purpose Input).
Signed-off-by: Andrew F. Davis <afd@ti.com>
---
drivers/gpio/Kconfig | 6 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-pisosr.c | 188 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 195 insertions(+)
create mode 100644 drivers/gpio/gpio-pisosr.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index c88dd24..bec3489 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1011,6 +1011,12 @@ config GPIO_MC33880
SPI driver for Freescale MC33880 high-side/low-side switch.
This provides GPIO interface supporting inputs and outputs.
+config GPIO_PISOSR
+ tristate "Generic parallel-in/serial-out shift register"
+ help
+ GPIO driver for SPI compatible parallel-in/serial-out shift
+ registers. These are input only devices.
+
endmenu
menu "SPI or I2C GPIO expanders"
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index ece7d7c..8e4f09f 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -75,6 +75,7 @@ obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o
obj-$(CONFIG_GPIO_PCA953X) += gpio-pca953x.o
obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o
obj-$(CONFIG_GPIO_PCH) += gpio-pch.o
+obj-$(CONFIG_GPIO_PISOSR) += gpio-pisosr.o
obj-$(CONFIG_GPIO_PL061) += gpio-pl061.o
obj-$(CONFIG_GPIO_PXA) += gpio-pxa.o
obj-$(CONFIG_GPIO_RC5T583) += gpio-rc5t583.o
diff --git a/drivers/gpio/gpio-pisosr.c b/drivers/gpio/gpio-pisosr.c
new file mode 100644
index 0000000..58ea08d
--- /dev/null
+++ b/drivers/gpio/gpio-pisosr.c
@@ -0,0 +1,188 @@
+/*
+ * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
+ * Andrew F. Davis <afd@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether expressed or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License version 2 for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/spi/spi.h>
+
+#define DEFAULT_NGPIO 8
+
+/**
+ * struct pisosr_gpio - GPIO driver data
+ * @chip: GPIO controller chip
+ * @spi: SPI device pointer
+ * @buffer: Buffer for device reads
+ * @buffer_size: Size of buffer
+ * @load_gpio: GPIO pin used to load input into device
+ * @lock: Protects read sequences
+ */
+struct pisosr_gpio {
+ struct gpio_chip chip;
+ struct spi_device *spi;
+ u8 *buffer;
+ size_t buffer_size;
+ struct gpio_desc *load_gpio;
+ struct mutex lock;
+};
+
+static int pisosr_gpio_refresh(struct pisosr_gpio *gpio)
+{
+ int ret;
+
+ mutex_lock(&gpio->lock);
+
+ if (gpio->load_gpio) {
+ gpiod_set_value(gpio->load_gpio, 1);
+ udelay(1); /* registers load time (~10ns) */
+ gpiod_set_value(gpio->load_gpio, 0);
+ udelay(1); /* registers recovery time (~5ns) */
+ }
+
+ ret = spi_read(gpio->spi, gpio->buffer, gpio->buffer_size);
+ if (ret)
+ return ret;
+
+ mutex_unlock(&gpio->lock);
+
+ return 0;
+}
+
+static int pisosr_gpio_get_direction(struct gpio_chip *chip,
+ unsigned offset)
+{
+ /* This device always input */
+ return 1;
+}
+
+static int pisosr_gpio_direction_input(struct gpio_chip *chip,
+ unsigned offset)
+{
+ /* This device always input */
+ return 0;
+}
+
+static int pisosr_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ /* This device is input only */
+ return -EINVAL;
+}
+
+static int pisosr_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct pisosr_gpio *gpio = gpiochip_get_data(chip);
+
+ /* Refresh may not always be needed */
+ pisosr_gpio_refresh(gpio);
+
+ return (gpio->buffer[offset / 8] >> (offset % 8)) & 0x1;
+}
+
+static struct gpio_chip template_chip = {
+ .label = "pisosr-gpio",
+ .owner = THIS_MODULE,
+ .get_direction = pisosr_gpio_get_direction,
+ .direction_input = pisosr_gpio_direction_input,
+ .direction_output = pisosr_gpio_direction_output,
+ .get = pisosr_gpio_get,
+ .base = -1,
+ .ngpio = DEFAULT_NGPIO,
+ .can_sleep = true,
+};
+
+static int pisosr_gpio_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct pisosr_gpio *gpio;
+ int ret;
+
+ gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
+ if (!gpio)
+ return -ENOMEM;
+
+ spi_set_drvdata(spi, gpio);
+
+ gpio->chip = template_chip;
+ gpio->chip.parent = dev;
+ of_property_read_u16(dev->of_node, "ngpios", &gpio->chip.ngpio);
+
+ gpio->spi = spi;
+
+ gpio->buffer_size = DIV_ROUND_UP(gpio->chip.ngpio, 8);
+ gpio->buffer = devm_kzalloc(dev, gpio->buffer_size, GFP_KERNEL);
+ if (!gpio->buffer)
+ return -ENOMEM;
+
+ gpio->load_gpio = devm_gpiod_get(dev, "load", GPIOD_OUT_LOW);
+ if (IS_ERR(gpio->load_gpio)) {
+ ret = PTR_ERR(gpio->load_gpio);
+ if (ret != -ENOENT && ret != -ENOSYS) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "Unable to allocate load GPIO\n");
+ return ret;
+ }
+ gpio->load_gpio = NULL;
+ }
+
+ mutex_init(&gpio->lock);
+
+ ret = gpiochip_add_data(&gpio->chip, gpio);
+ if (ret < 0) {
+ dev_err(dev, "Unable to register gpiochip\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int pisosr_gpio_remove(struct spi_device *spi)
+{
+ struct pisosr_gpio *gpio = spi_get_drvdata(spi);
+
+ gpiochip_remove(&gpio->chip);
+
+ mutex_destroy(&gpio->lock);
+
+ return 0;
+}
+
+static const struct spi_device_id pisosr_gpio_id_table[] = {
+ { "pisosr-gpio", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(spi, pisosr_gpio_id_table);
+
+static const struct of_device_id pisosr_gpio_of_match_table[] = {
+ { .compatible = "pisosr-gpio", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, pisosr_gpio_of_match_table);
+
+static struct spi_driver pisosr_gpio_driver = {
+ .driver = {
+ .name = "pisosr-gpio",
+ .of_match_table = pisosr_gpio_of_match_table,
+ },
+ .probe = pisosr_gpio_probe,
+ .remove = pisosr_gpio_remove,
+ .id_table = pisosr_gpio_id_table,
+};
+module_spi_driver(pisosr_gpio_driver);
+
+MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
+MODULE_DESCRIPTION("SPI Compatible PISO Shift Register GPIO Driver");
+MODULE_LICENSE("GPL v2");
--
2.7.0
^ permalink raw reply related [flat|nested] 18+ messages in thread* Re: [PATCH v2 2/2] gpio: Add driver for SPI serializers
2016-01-25 16:37 ` Andrew F. Davis
@ 2016-01-29 6:31 ` Sean Nyekjær
-1 siblings, 0 replies; 18+ messages in thread
From: Sean Nyekjær @ 2016-01-29 6:31 UTC (permalink / raw)
To: Andrew F. Davis, Linus Walleij, Alexandre Courbot, Mark Brown,
Rob Herring, Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala
Cc: linux-gpio, devicetree, linux-kernel
On 2016-01-25 17:37, Andrew F. Davis wrote:
> Add generic parallel-in/serial-out shift register GPIO driver.
>
> This includes SPI compatible devices like SN74165 serial-out shift
> registers and the SN65HVS88x series of industrial serializers that can
> be read over the SPI bus and used for GPI (General Purpose Input).
>
> Signed-off-by: Andrew F. Davis <afd@ti.com>
> ---
> drivers/gpio/Kconfig | 6 ++
> drivers/gpio/Makefile | 1 +
> drivers/gpio/gpio-pisosr.c | 188 +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 195 insertions(+)
> create mode 100644 drivers/gpio/gpio-pisosr.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index c88dd24..bec3489 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -1011,6 +1011,12 @@ config GPIO_MC33880
> SPI driver for Freescale MC33880 high-side/low-side switch.
> This provides GPIO interface supporting inputs and outputs.
>
> +config GPIO_PISOSR
> + tristate "Generic parallel-in/serial-out shift register"
> + help
> + GPIO driver for SPI compatible parallel-in/serial-out shift
> + registers. These are input only devices.
> +
> endmenu
>
> menu "SPI or I2C GPIO expanders"
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index ece7d7c..8e4f09f 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -75,6 +75,7 @@ obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o
> obj-$(CONFIG_GPIO_PCA953X) += gpio-pca953x.o
> obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o
> obj-$(CONFIG_GPIO_PCH) += gpio-pch.o
> +obj-$(CONFIG_GPIO_PISOSR) += gpio-pisosr.o
> obj-$(CONFIG_GPIO_PL061) += gpio-pl061.o
> obj-$(CONFIG_GPIO_PXA) += gpio-pxa.o
> obj-$(CONFIG_GPIO_RC5T583) += gpio-rc5t583.o
> diff --git a/drivers/gpio/gpio-pisosr.c b/drivers/gpio/gpio-pisosr.c
> new file mode 100644
> index 0000000..58ea08d
> --- /dev/null
> +++ b/drivers/gpio/gpio-pisosr.c
> @@ -0,0 +1,188 @@
> +/*
> + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
> + * Andrew F. Davis <afd@ti.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> + * kind, whether expressed or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License version 2 for more details.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/spi/spi.h>
> +
> +#define DEFAULT_NGPIO 8
> +
> +/**
> + * struct pisosr_gpio - GPIO driver data
> + * @chip: GPIO controller chip
> + * @spi: SPI device pointer
> + * @buffer: Buffer for device reads
> + * @buffer_size: Size of buffer
> + * @load_gpio: GPIO pin used to load input into device
> + * @lock: Protects read sequences
> + */
> +struct pisosr_gpio {
> + struct gpio_chip chip;
> + struct spi_device *spi;
> + u8 *buffer;
> + size_t buffer_size;
> + struct gpio_desc *load_gpio;
> + struct mutex lock;
> +};
> +
> +static int pisosr_gpio_refresh(struct pisosr_gpio *gpio)
> +{
> + int ret;
> +
> + mutex_lock(&gpio->lock);
> +
> + if (gpio->load_gpio) {
> + gpiod_set_value(gpio->load_gpio, 1);
> + udelay(1); /* registers load time (~10ns) */
> + gpiod_set_value(gpio->load_gpio, 0);
> + udelay(1); /* registers recovery time (~5ns) */
> + }
> +
> + ret = spi_read(gpio->spi, gpio->buffer, gpio->buffer_size);
> + if (ret)
> + return ret;
> +
> + mutex_unlock(&gpio->lock);
> +
> + return 0;
> +}
> +
> +static int pisosr_gpio_get_direction(struct gpio_chip *chip,
> + unsigned offset)
> +{
> + /* This device always input */
> + return 1;
> +}
> +
> +static int pisosr_gpio_direction_input(struct gpio_chip *chip,
> + unsigned offset)
> +{
> + /* This device always input */
> + return 0;
> +}
> +
> +static int pisosr_gpio_direction_output(struct gpio_chip *chip,
> + unsigned offset, int value)
> +{
> + /* This device is input only */
> + return -EINVAL;
> +}
> +
> +static int pisosr_gpio_get(struct gpio_chip *chip, unsigned offset)
> +{
> + struct pisosr_gpio *gpio = gpiochip_get_data(chip);
> +
> + /* Refresh may not always be needed */
> + pisosr_gpio_refresh(gpio);
> +
> + return (gpio->buffer[offset / 8] >> (offset % 8)) & 0x1;
> +}
> +
> +static struct gpio_chip template_chip = {
> + .label = "pisosr-gpio",
> + .owner = THIS_MODULE,
> + .get_direction = pisosr_gpio_get_direction,
> + .direction_input = pisosr_gpio_direction_input,
> + .direction_output = pisosr_gpio_direction_output,
> + .get = pisosr_gpio_get,
> + .base = -1,
> + .ngpio = DEFAULT_NGPIO,
> + .can_sleep = true,
> +};
> +
> +static int pisosr_gpio_probe(struct spi_device *spi)
> +{
> + struct device *dev = &spi->dev;
> + struct pisosr_gpio *gpio;
> + int ret;
> +
> + gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
> + if (!gpio)
> + return -ENOMEM;
> +
> + spi_set_drvdata(spi, gpio);
> +
> + gpio->chip = template_chip;
> + gpio->chip.parent = dev;
> + of_property_read_u16(dev->of_node, "ngpios", &gpio->chip.ngpio);
> +
> + gpio->spi = spi;
> +
> + gpio->buffer_size = DIV_ROUND_UP(gpio->chip.ngpio, 8);
> + gpio->buffer = devm_kzalloc(dev, gpio->buffer_size, GFP_KERNEL);
> + if (!gpio->buffer)
> + return -ENOMEM;
> +
> + gpio->load_gpio = devm_gpiod_get(dev, "load", GPIOD_OUT_LOW);
> + if (IS_ERR(gpio->load_gpio)) {
> + ret = PTR_ERR(gpio->load_gpio);
> + if (ret != -ENOENT && ret != -ENOSYS) {
> + if (ret != -EPROBE_DEFER)
> + dev_err(dev, "Unable to allocate load GPIO\n");
> + return ret;
> + }
> + gpio->load_gpio = NULL;
> + }
> +
> + mutex_init(&gpio->lock);
> +
> + ret = gpiochip_add_data(&gpio->chip, gpio);
> + if (ret < 0) {
> + dev_err(dev, "Unable to register gpiochip\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int pisosr_gpio_remove(struct spi_device *spi)
> +{
> + struct pisosr_gpio *gpio = spi_get_drvdata(spi);
> +
> + gpiochip_remove(&gpio->chip);
> +
> + mutex_destroy(&gpio->lock);
> +
> + return 0;
> +}
> +
> +static const struct spi_device_id pisosr_gpio_id_table[] = {
> + { "pisosr-gpio", },
> + { /* sentinel */ }
Please add this :-)
{"ti,sn65hvs885", 0},
> +};
> +MODULE_DEVICE_TABLE(spi, pisosr_gpio_id_table);
> +
> +static const struct of_device_id pisosr_gpio_of_match_table[] = {
> + { .compatible = "pisosr-gpio", },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, pisosr_gpio_of_match_table);
> +
> +static struct spi_driver pisosr_gpio_driver = {
> + .driver = {
> + .name = "pisosr-gpio",
> + .of_match_table = pisosr_gpio_of_match_table,
> + },
> + .probe = pisosr_gpio_probe,
> + .remove = pisosr_gpio_remove,
> + .id_table = pisosr_gpio_id_table,
> +};
> +module_spi_driver(pisosr_gpio_driver);
> +
> +MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
> +MODULE_DESCRIPTION("SPI Compatible PISO Shift Register GPIO Driver");
> +MODULE_LICENSE("GPL v2");
Hi Andrew
I have created an driver for the sn65hvs885 at the same time as you, and
the output is nearly identical :-)
We are both missing the support for cacading devices, but i guess that
can come later on.
/Sean
^ permalink raw reply [flat|nested] 18+ messages in thread* Re: [PATCH v2 2/2] gpio: Add driver for SPI serializers
@ 2016-01-29 6:31 ` Sean Nyekjær
0 siblings, 0 replies; 18+ messages in thread
From: Sean Nyekjær @ 2016-01-29 6:31 UTC (permalink / raw)
To: Andrew F. Davis, Linus Walleij, Alexandre Courbot, Mark Brown,
Rob Herring, Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala
Cc: linux-gpio, devicetree, linux-kernel
On 2016-01-25 17:37, Andrew F. Davis wrote:
> Add generic parallel-in/serial-out shift register GPIO driver.
>
> This includes SPI compatible devices like SN74165 serial-out shift
> registers and the SN65HVS88x series of industrial serializers that can
> be read over the SPI bus and used for GPI (General Purpose Input).
>
> Signed-off-by: Andrew F. Davis <afd@ti.com>
> ---
> drivers/gpio/Kconfig | 6 ++
> drivers/gpio/Makefile | 1 +
> drivers/gpio/gpio-pisosr.c | 188 +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 195 insertions(+)
> create mode 100644 drivers/gpio/gpio-pisosr.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index c88dd24..bec3489 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -1011,6 +1011,12 @@ config GPIO_MC33880
> SPI driver for Freescale MC33880 high-side/low-side switch.
> This provides GPIO interface supporting inputs and outputs.
>
> +config GPIO_PISOSR
> + tristate "Generic parallel-in/serial-out shift register"
> + help
> + GPIO driver for SPI compatible parallel-in/serial-out shift
> + registers. These are input only devices.
> +
> endmenu
>
> menu "SPI or I2C GPIO expanders"
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index ece7d7c..8e4f09f 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -75,6 +75,7 @@ obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o
> obj-$(CONFIG_GPIO_PCA953X) += gpio-pca953x.o
> obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o
> obj-$(CONFIG_GPIO_PCH) += gpio-pch.o
> +obj-$(CONFIG_GPIO_PISOSR) += gpio-pisosr.o
> obj-$(CONFIG_GPIO_PL061) += gpio-pl061.o
> obj-$(CONFIG_GPIO_PXA) += gpio-pxa.o
> obj-$(CONFIG_GPIO_RC5T583) += gpio-rc5t583.o
> diff --git a/drivers/gpio/gpio-pisosr.c b/drivers/gpio/gpio-pisosr.c
> new file mode 100644
> index 0000000..58ea08d
> --- /dev/null
> +++ b/drivers/gpio/gpio-pisosr.c
> @@ -0,0 +1,188 @@
> +/*
> + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
> + * Andrew F. Davis <afd@ti.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> + * kind, whether expressed or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License version 2 for more details.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/spi/spi.h>
> +
> +#define DEFAULT_NGPIO 8
> +
> +/**
> + * struct pisosr_gpio - GPIO driver data
> + * @chip: GPIO controller chip
> + * @spi: SPI device pointer
> + * @buffer: Buffer for device reads
> + * @buffer_size: Size of buffer
> + * @load_gpio: GPIO pin used to load input into device
> + * @lock: Protects read sequences
> + */
> +struct pisosr_gpio {
> + struct gpio_chip chip;
> + struct spi_device *spi;
> + u8 *buffer;
> + size_t buffer_size;
> + struct gpio_desc *load_gpio;
> + struct mutex lock;
> +};
> +
> +static int pisosr_gpio_refresh(struct pisosr_gpio *gpio)
> +{
> + int ret;
> +
> + mutex_lock(&gpio->lock);
> +
> + if (gpio->load_gpio) {
> + gpiod_set_value(gpio->load_gpio, 1);
> + udelay(1); /* registers load time (~10ns) */
> + gpiod_set_value(gpio->load_gpio, 0);
> + udelay(1); /* registers recovery time (~5ns) */
> + }
> +
> + ret = spi_read(gpio->spi, gpio->buffer, gpio->buffer_size);
> + if (ret)
> + return ret;
> +
> + mutex_unlock(&gpio->lock);
> +
> + return 0;
> +}
> +
> +static int pisosr_gpio_get_direction(struct gpio_chip *chip,
> + unsigned offset)
> +{
> + /* This device always input */
> + return 1;
> +}
> +
> +static int pisosr_gpio_direction_input(struct gpio_chip *chip,
> + unsigned offset)
> +{
> + /* This device always input */
> + return 0;
> +}
> +
> +static int pisosr_gpio_direction_output(struct gpio_chip *chip,
> + unsigned offset, int value)
> +{
> + /* This device is input only */
> + return -EINVAL;
> +}
> +
> +static int pisosr_gpio_get(struct gpio_chip *chip, unsigned offset)
> +{
> + struct pisosr_gpio *gpio = gpiochip_get_data(chip);
> +
> + /* Refresh may not always be needed */
> + pisosr_gpio_refresh(gpio);
> +
> + return (gpio->buffer[offset / 8] >> (offset % 8)) & 0x1;
> +}
> +
> +static struct gpio_chip template_chip = {
> + .label = "pisosr-gpio",
> + .owner = THIS_MODULE,
> + .get_direction = pisosr_gpio_get_direction,
> + .direction_input = pisosr_gpio_direction_input,
> + .direction_output = pisosr_gpio_direction_output,
> + .get = pisosr_gpio_get,
> + .base = -1,
> + .ngpio = DEFAULT_NGPIO,
> + .can_sleep = true,
> +};
> +
> +static int pisosr_gpio_probe(struct spi_device *spi)
> +{
> + struct device *dev = &spi->dev;
> + struct pisosr_gpio *gpio;
> + int ret;
> +
> + gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
> + if (!gpio)
> + return -ENOMEM;
> +
> + spi_set_drvdata(spi, gpio);
> +
> + gpio->chip = template_chip;
> + gpio->chip.parent = dev;
> + of_property_read_u16(dev->of_node, "ngpios", &gpio->chip.ngpio);
> +
> + gpio->spi = spi;
> +
> + gpio->buffer_size = DIV_ROUND_UP(gpio->chip.ngpio, 8);
> + gpio->buffer = devm_kzalloc(dev, gpio->buffer_size, GFP_KERNEL);
> + if (!gpio->buffer)
> + return -ENOMEM;
> +
> + gpio->load_gpio = devm_gpiod_get(dev, "load", GPIOD_OUT_LOW);
> + if (IS_ERR(gpio->load_gpio)) {
> + ret = PTR_ERR(gpio->load_gpio);
> + if (ret != -ENOENT && ret != -ENOSYS) {
> + if (ret != -EPROBE_DEFER)
> + dev_err(dev, "Unable to allocate load GPIO\n");
> + return ret;
> + }
> + gpio->load_gpio = NULL;
> + }
> +
> + mutex_init(&gpio->lock);
> +
> + ret = gpiochip_add_data(&gpio->chip, gpio);
> + if (ret < 0) {
> + dev_err(dev, "Unable to register gpiochip\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int pisosr_gpio_remove(struct spi_device *spi)
> +{
> + struct pisosr_gpio *gpio = spi_get_drvdata(spi);
> +
> + gpiochip_remove(&gpio->chip);
> +
> + mutex_destroy(&gpio->lock);
> +
> + return 0;
> +}
> +
> +static const struct spi_device_id pisosr_gpio_id_table[] = {
> + { "pisosr-gpio", },
> + { /* sentinel */ }
Please add this :-)
{"ti,sn65hvs885", 0},
> +};
> +MODULE_DEVICE_TABLE(spi, pisosr_gpio_id_table);
> +
> +static const struct of_device_id pisosr_gpio_of_match_table[] = {
> + { .compatible = "pisosr-gpio", },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, pisosr_gpio_of_match_table);
> +
> +static struct spi_driver pisosr_gpio_driver = {
> + .driver = {
> + .name = "pisosr-gpio",
> + .of_match_table = pisosr_gpio_of_match_table,
> + },
> + .probe = pisosr_gpio_probe,
> + .remove = pisosr_gpio_remove,
> + .id_table = pisosr_gpio_id_table,
> +};
> +module_spi_driver(pisosr_gpio_driver);
> +
> +MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
> +MODULE_DESCRIPTION("SPI Compatible PISO Shift Register GPIO Driver");
> +MODULE_LICENSE("GPL v2");
Hi Andrew
I have created an driver for the sn65hvs885 at the same time as you, and
the output is nearly identical :-)
We are both missing the support for cacading devices, but i guess that
can come later on.
/Sean
^ permalink raw reply [flat|nested] 18+ messages in thread* Re: [PATCH v2 2/2] gpio: Add driver for SPI serializers
2016-01-29 6:31 ` Sean Nyekjær
@ 2016-02-01 14:52 ` Andrew F. Davis
-1 siblings, 0 replies; 18+ messages in thread
From: Andrew F. Davis @ 2016-02-01 14:52 UTC (permalink / raw)
To: Sean Nyekjær, Linus Walleij, Alexandre Courbot, Mark Brown,
Rob Herring, Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala
Cc: linux-gpio, devicetree, linux-kernel
On 01/29/2016 12:31 AM, Sean Nyekjær wrote:
>
>
> On 2016-01-25 17:37, Andrew F. Davis wrote:
>> Add generic parallel-in/serial-out shift register GPIO driver.
>>
>> This includes SPI compatible devices like SN74165 serial-out shift
>> registers and the SN65HVS88x series of industrial serializers that can
>> be read over the SPI bus and used for GPI (General Purpose Input).
>>
>> Signed-off-by: Andrew F. Davis <afd@ti.com>
>> ---
>> drivers/gpio/Kconfig | 6 ++
>> drivers/gpio/Makefile | 1 +
>> drivers/gpio/gpio-pisosr.c | 188 +++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 195 insertions(+)
>> create mode 100644 drivers/gpio/gpio-pisosr.c
>>
>> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
>> index c88dd24..bec3489 100644
>> --- a/drivers/gpio/Kconfig
>> +++ b/drivers/gpio/Kconfig
>> @@ -1011,6 +1011,12 @@ config GPIO_MC33880
>> SPI driver for Freescale MC33880 high-side/low-side switch.
>> This provides GPIO interface supporting inputs and outputs.
>> +config GPIO_PISOSR
>> + tristate "Generic parallel-in/serial-out shift register"
>> + help
>> + GPIO driver for SPI compatible parallel-in/serial-out shift
>> + registers. These are input only devices.
>> +
>> endmenu
>> menu "SPI or I2C GPIO expanders"
>> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
>> index ece7d7c..8e4f09f 100644
>> --- a/drivers/gpio/Makefile
>> +++ b/drivers/gpio/Makefile
>> @@ -75,6 +75,7 @@ obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o
>> obj-$(CONFIG_GPIO_PCA953X) += gpio-pca953x.o
>> obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o
>> obj-$(CONFIG_GPIO_PCH) += gpio-pch.o
>> +obj-$(CONFIG_GPIO_PISOSR) += gpio-pisosr.o
>> obj-$(CONFIG_GPIO_PL061) += gpio-pl061.o
>> obj-$(CONFIG_GPIO_PXA) += gpio-pxa.o
>> obj-$(CONFIG_GPIO_RC5T583) += gpio-rc5t583.o
>> diff --git a/drivers/gpio/gpio-pisosr.c b/drivers/gpio/gpio-pisosr.c
>> new file mode 100644
>> index 0000000..58ea08d
>> --- /dev/null
>> +++ b/drivers/gpio/gpio-pisosr.c
>> @@ -0,0 +1,188 @@
>> +/*
>> + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
>> + * Andrew F. Davis <afd@ti.com>
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
>> + * kind, whether expressed or implied; without even the implied warranty
>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License version 2 for more details.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/gpio/driver.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/spi/spi.h>
>> +
>> +#define DEFAULT_NGPIO 8
>> +
>> +/**
>> + * struct pisosr_gpio - GPIO driver data
>> + * @chip: GPIO controller chip
>> + * @spi: SPI device pointer
>> + * @buffer: Buffer for device reads
>> + * @buffer_size: Size of buffer
>> + * @load_gpio: GPIO pin used to load input into device
>> + * @lock: Protects read sequences
>> + */
>> +struct pisosr_gpio {
>> + struct gpio_chip chip;
>> + struct spi_device *spi;
>> + u8 *buffer;
>> + size_t buffer_size;
>> + struct gpio_desc *load_gpio;
>> + struct mutex lock;
>> +};
>> +
>> +static int pisosr_gpio_refresh(struct pisosr_gpio *gpio)
>> +{
>> + int ret;
>> +
>> + mutex_lock(&gpio->lock);
>> +
>> + if (gpio->load_gpio) {
>> + gpiod_set_value(gpio->load_gpio, 1);
>> + udelay(1); /* registers load time (~10ns) */
>> + gpiod_set_value(gpio->load_gpio, 0);
>> + udelay(1); /* registers recovery time (~5ns) */
>> + }
>> +
>> + ret = spi_read(gpio->spi, gpio->buffer, gpio->buffer_size);
>> + if (ret)
>> + return ret;
>> +
>> + mutex_unlock(&gpio->lock);
>> +
>> + return 0;
>> +}
>> +
>> +static int pisosr_gpio_get_direction(struct gpio_chip *chip,
>> + unsigned offset)
>> +{
>> + /* This device always input */
>> + return 1;
>> +}
>> +
>> +static int pisosr_gpio_direction_input(struct gpio_chip *chip,
>> + unsigned offset)
>> +{
>> + /* This device always input */
>> + return 0;
>> +}
>> +
>> +static int pisosr_gpio_direction_output(struct gpio_chip *chip,
>> + unsigned offset, int value)
>> +{
>> + /* This device is input only */
>> + return -EINVAL;
>> +}
>> +
>> +static int pisosr_gpio_get(struct gpio_chip *chip, unsigned offset)
>> +{
>> + struct pisosr_gpio *gpio = gpiochip_get_data(chip);
>> +
>> + /* Refresh may not always be needed */
>> + pisosr_gpio_refresh(gpio);
>> +
>> + return (gpio->buffer[offset / 8] >> (offset % 8)) & 0x1;
>> +}
>> +
>> +static struct gpio_chip template_chip = {
>> + .label = "pisosr-gpio",
>> + .owner = THIS_MODULE,
>> + .get_direction = pisosr_gpio_get_direction,
>> + .direction_input = pisosr_gpio_direction_input,
>> + .direction_output = pisosr_gpio_direction_output,
>> + .get = pisosr_gpio_get,
>> + .base = -1,
>> + .ngpio = DEFAULT_NGPIO,
>> + .can_sleep = true,
>> +};
>> +
>> +static int pisosr_gpio_probe(struct spi_device *spi)
>> +{
>> + struct device *dev = &spi->dev;
>> + struct pisosr_gpio *gpio;
>> + int ret;
>> +
>> + gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
>> + if (!gpio)
>> + return -ENOMEM;
>> +
>> + spi_set_drvdata(spi, gpio);
>> +
>> + gpio->chip = template_chip;
>> + gpio->chip.parent = dev;
>> + of_property_read_u16(dev->of_node, "ngpios", &gpio->chip.ngpio);
>> +
>> + gpio->spi = spi;
>> +
>> + gpio->buffer_size = DIV_ROUND_UP(gpio->chip.ngpio, 8);
>> + gpio->buffer = devm_kzalloc(dev, gpio->buffer_size, GFP_KERNEL);
>> + if (!gpio->buffer)
>> + return -ENOMEM;
>> +
>> + gpio->load_gpio = devm_gpiod_get(dev, "load", GPIOD_OUT_LOW);
>> + if (IS_ERR(gpio->load_gpio)) {
>> + ret = PTR_ERR(gpio->load_gpio);
>> + if (ret != -ENOENT && ret != -ENOSYS) {
>> + if (ret != -EPROBE_DEFER)
>> + dev_err(dev, "Unable to allocate load GPIO\n");
>> + return ret;
>> + }
>> + gpio->load_gpio = NULL;
>> + }
>> +
>> + mutex_init(&gpio->lock);
>> +
>> + ret = gpiochip_add_data(&gpio->chip, gpio);
>> + if (ret < 0) {
>> + dev_err(dev, "Unable to register gpiochip\n");
>> + return ret;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int pisosr_gpio_remove(struct spi_device *spi)
>> +{
>> + struct pisosr_gpio *gpio = spi_get_drvdata(spi);
>> +
>> + gpiochip_remove(&gpio->chip);
>> +
>> + mutex_destroy(&gpio->lock);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct spi_device_id pisosr_gpio_id_table[] = {
>> + { "pisosr-gpio", },
>> + { /* sentinel */ }
> Please add this :-)
> {"ti,sn65hvs885", 0},
See below.
>> +};
>> +MODULE_DEVICE_TABLE(spi, pisosr_gpio_id_table);
>> +
>> +static const struct of_device_id pisosr_gpio_of_match_table[] = {
>> + { .compatible = "pisosr-gpio", },
>> + { /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, pisosr_gpio_of_match_table);
>> +
>> +static struct spi_driver pisosr_gpio_driver = {
>> + .driver = {
>> + .name = "pisosr-gpio",
>> + .of_match_table = pisosr_gpio_of_match_table,
>> + },
>> + .probe = pisosr_gpio_probe,
>> + .remove = pisosr_gpio_remove,
>> + .id_table = pisosr_gpio_id_table,
>> +};
>> +module_spi_driver(pisosr_gpio_driver);
>> +
>> +MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
>> +MODULE_DESCRIPTION("SPI Compatible PISO Shift Register GPIO Driver");
>> +MODULE_LICENSE("GPL v2");
> Hi Andrew
>
> I have created an driver for the sn65hvs885 at the same time as you, and the output is nearly identical :-)
> We are both missing the support for cacading devices, but i guess that can come later on.
>
> /Sean
Hi Sean,
This started as a driver for the sn65hvs88*2*, after seeing other drivers
for similar parts I found that these input shift-register devices interface
mostly the same way, so a more generic catch-all driver might be more
useful.
I would like to avoid explicitly putting the individual part names that may be
compatible in this driver for reasons described well by Rob's comment[0]. If
you disagree I don't have any real serious qualms with adding some part names.
Also by allowing a variable number of bits to be defined in DT I think
cascaded devices should work with this driver already.
[0] https://lkml.org/lkml/2016/1/28/581
Andrew
^ permalink raw reply [flat|nested] 18+ messages in thread* Re: [PATCH v2 2/2] gpio: Add driver for SPI serializers
@ 2016-02-01 14:52 ` Andrew F. Davis
0 siblings, 0 replies; 18+ messages in thread
From: Andrew F. Davis @ 2016-02-01 14:52 UTC (permalink / raw)
To: Sean Nyekjær, Linus Walleij, Alexandre Courbot, Mark Brown,
Rob Herring, Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala
Cc: linux-gpio, devicetree, linux-kernel
On 01/29/2016 12:31 AM, Sean Nyekjær wrote:
>
>
> On 2016-01-25 17:37, Andrew F. Davis wrote:
>> Add generic parallel-in/serial-out shift register GPIO driver.
>>
>> This includes SPI compatible devices like SN74165 serial-out shift
>> registers and the SN65HVS88x series of industrial serializers that can
>> be read over the SPI bus and used for GPI (General Purpose Input).
>>
>> Signed-off-by: Andrew F. Davis <afd@ti.com>
>> ---
>> drivers/gpio/Kconfig | 6 ++
>> drivers/gpio/Makefile | 1 +
>> drivers/gpio/gpio-pisosr.c | 188 +++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 195 insertions(+)
>> create mode 100644 drivers/gpio/gpio-pisosr.c
>>
>> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
>> index c88dd24..bec3489 100644
>> --- a/drivers/gpio/Kconfig
>> +++ b/drivers/gpio/Kconfig
>> @@ -1011,6 +1011,12 @@ config GPIO_MC33880
>> SPI driver for Freescale MC33880 high-side/low-side switch.
>> This provides GPIO interface supporting inputs and outputs.
>> +config GPIO_PISOSR
>> + tristate "Generic parallel-in/serial-out shift register"
>> + help
>> + GPIO driver for SPI compatible parallel-in/serial-out shift
>> + registers. These are input only devices.
>> +
>> endmenu
>> menu "SPI or I2C GPIO expanders"
>> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
>> index ece7d7c..8e4f09f 100644
>> --- a/drivers/gpio/Makefile
>> +++ b/drivers/gpio/Makefile
>> @@ -75,6 +75,7 @@ obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o
>> obj-$(CONFIG_GPIO_PCA953X) += gpio-pca953x.o
>> obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o
>> obj-$(CONFIG_GPIO_PCH) += gpio-pch.o
>> +obj-$(CONFIG_GPIO_PISOSR) += gpio-pisosr.o
>> obj-$(CONFIG_GPIO_PL061) += gpio-pl061.o
>> obj-$(CONFIG_GPIO_PXA) += gpio-pxa.o
>> obj-$(CONFIG_GPIO_RC5T583) += gpio-rc5t583.o
>> diff --git a/drivers/gpio/gpio-pisosr.c b/drivers/gpio/gpio-pisosr.c
>> new file mode 100644
>> index 0000000..58ea08d
>> --- /dev/null
>> +++ b/drivers/gpio/gpio-pisosr.c
>> @@ -0,0 +1,188 @@
>> +/*
>> + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
>> + * Andrew F. Davis <afd@ti.com>
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
>> + * kind, whether expressed or implied; without even the implied warranty
>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License version 2 for more details.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/gpio/driver.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/spi/spi.h>
>> +
>> +#define DEFAULT_NGPIO 8
>> +
>> +/**
>> + * struct pisosr_gpio - GPIO driver data
>> + * @chip: GPIO controller chip
>> + * @spi: SPI device pointer
>> + * @buffer: Buffer for device reads
>> + * @buffer_size: Size of buffer
>> + * @load_gpio: GPIO pin used to load input into device
>> + * @lock: Protects read sequences
>> + */
>> +struct pisosr_gpio {
>> + struct gpio_chip chip;
>> + struct spi_device *spi;
>> + u8 *buffer;
>> + size_t buffer_size;
>> + struct gpio_desc *load_gpio;
>> + struct mutex lock;
>> +};
>> +
>> +static int pisosr_gpio_refresh(struct pisosr_gpio *gpio)
>> +{
>> + int ret;
>> +
>> + mutex_lock(&gpio->lock);
>> +
>> + if (gpio->load_gpio) {
>> + gpiod_set_value(gpio->load_gpio, 1);
>> + udelay(1); /* registers load time (~10ns) */
>> + gpiod_set_value(gpio->load_gpio, 0);
>> + udelay(1); /* registers recovery time (~5ns) */
>> + }
>> +
>> + ret = spi_read(gpio->spi, gpio->buffer, gpio->buffer_size);
>> + if (ret)
>> + return ret;
>> +
>> + mutex_unlock(&gpio->lock);
>> +
>> + return 0;
>> +}
>> +
>> +static int pisosr_gpio_get_direction(struct gpio_chip *chip,
>> + unsigned offset)
>> +{
>> + /* This device always input */
>> + return 1;
>> +}
>> +
>> +static int pisosr_gpio_direction_input(struct gpio_chip *chip,
>> + unsigned offset)
>> +{
>> + /* This device always input */
>> + return 0;
>> +}
>> +
>> +static int pisosr_gpio_direction_output(struct gpio_chip *chip,
>> + unsigned offset, int value)
>> +{
>> + /* This device is input only */
>> + return -EINVAL;
>> +}
>> +
>> +static int pisosr_gpio_get(struct gpio_chip *chip, unsigned offset)
>> +{
>> + struct pisosr_gpio *gpio = gpiochip_get_data(chip);
>> +
>> + /* Refresh may not always be needed */
>> + pisosr_gpio_refresh(gpio);
>> +
>> + return (gpio->buffer[offset / 8] >> (offset % 8)) & 0x1;
>> +}
>> +
>> +static struct gpio_chip template_chip = {
>> + .label = "pisosr-gpio",
>> + .owner = THIS_MODULE,
>> + .get_direction = pisosr_gpio_get_direction,
>> + .direction_input = pisosr_gpio_direction_input,
>> + .direction_output = pisosr_gpio_direction_output,
>> + .get = pisosr_gpio_get,
>> + .base = -1,
>> + .ngpio = DEFAULT_NGPIO,
>> + .can_sleep = true,
>> +};
>> +
>> +static int pisosr_gpio_probe(struct spi_device *spi)
>> +{
>> + struct device *dev = &spi->dev;
>> + struct pisosr_gpio *gpio;
>> + int ret;
>> +
>> + gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
>> + if (!gpio)
>> + return -ENOMEM;
>> +
>> + spi_set_drvdata(spi, gpio);
>> +
>> + gpio->chip = template_chip;
>> + gpio->chip.parent = dev;
>> + of_property_read_u16(dev->of_node, "ngpios", &gpio->chip.ngpio);
>> +
>> + gpio->spi = spi;
>> +
>> + gpio->buffer_size = DIV_ROUND_UP(gpio->chip.ngpio, 8);
>> + gpio->buffer = devm_kzalloc(dev, gpio->buffer_size, GFP_KERNEL);
>> + if (!gpio->buffer)
>> + return -ENOMEM;
>> +
>> + gpio->load_gpio = devm_gpiod_get(dev, "load", GPIOD_OUT_LOW);
>> + if (IS_ERR(gpio->load_gpio)) {
>> + ret = PTR_ERR(gpio->load_gpio);
>> + if (ret != -ENOENT && ret != -ENOSYS) {
>> + if (ret != -EPROBE_DEFER)
>> + dev_err(dev, "Unable to allocate load GPIO\n");
>> + return ret;
>> + }
>> + gpio->load_gpio = NULL;
>> + }
>> +
>> + mutex_init(&gpio->lock);
>> +
>> + ret = gpiochip_add_data(&gpio->chip, gpio);
>> + if (ret < 0) {
>> + dev_err(dev, "Unable to register gpiochip\n");
>> + return ret;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int pisosr_gpio_remove(struct spi_device *spi)
>> +{
>> + struct pisosr_gpio *gpio = spi_get_drvdata(spi);
>> +
>> + gpiochip_remove(&gpio->chip);
>> +
>> + mutex_destroy(&gpio->lock);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct spi_device_id pisosr_gpio_id_table[] = {
>> + { "pisosr-gpio", },
>> + { /* sentinel */ }
> Please add this :-)
> {"ti,sn65hvs885", 0},
See below.
>> +};
>> +MODULE_DEVICE_TABLE(spi, pisosr_gpio_id_table);
>> +
>> +static const struct of_device_id pisosr_gpio_of_match_table[] = {
>> + { .compatible = "pisosr-gpio", },
>> + { /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, pisosr_gpio_of_match_table);
>> +
>> +static struct spi_driver pisosr_gpio_driver = {
>> + .driver = {
>> + .name = "pisosr-gpio",
>> + .of_match_table = pisosr_gpio_of_match_table,
>> + },
>> + .probe = pisosr_gpio_probe,
>> + .remove = pisosr_gpio_remove,
>> + .id_table = pisosr_gpio_id_table,
>> +};
>> +module_spi_driver(pisosr_gpio_driver);
>> +
>> +MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
>> +MODULE_DESCRIPTION("SPI Compatible PISO Shift Register GPIO Driver");
>> +MODULE_LICENSE("GPL v2");
> Hi Andrew
>
> I have created an driver for the sn65hvs885 at the same time as you, and the output is nearly identical :-)
> We are both missing the support for cacading devices, but i guess that can come later on.
>
> /Sean
Hi Sean,
This started as a driver for the sn65hvs88*2*, after seeing other drivers
for similar parts I found that these input shift-register devices interface
mostly the same way, so a more generic catch-all driver might be more
useful.
I would like to avoid explicitly putting the individual part names that may be
compatible in this driver for reasons described well by Rob's comment[0]. If
you disagree I don't have any real serious qualms with adding some part names.
Also by allowing a variable number of bits to be defined in DT I think
cascaded devices should work with this driver already.
[0] https://lkml.org/lkml/2016/1/28/581
Andrew
^ permalink raw reply [flat|nested] 18+ messages in thread* Re: [PATCH v2 2/2] gpio: Add driver for SPI serializers
2016-02-01 14:52 ` Andrew F. Davis
@ 2016-02-02 9:43 ` Sean Nyekjær
-1 siblings, 0 replies; 18+ messages in thread
From: Sean Nyekjær @ 2016-02-02 9:43 UTC (permalink / raw)
To: Andrew F. Davis, Linus Walleij, Alexandre Courbot, Mark Brown,
Rob Herring, Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala
Cc: linux-gpio, devicetree, linux-kernel
On 2016-02-01 15:52, Andrew F. Davis wrote:
> On 01/29/2016 12:31 AM, Sean Nyekjær wrote:
>>
>>
>> On 2016-01-25 17:37, Andrew F. Davis wrote:
>>> Add generic parallel-in/serial-out shift register GPIO driver.
>>>
>>> This includes SPI compatible devices like SN74165 serial-out shift
>>> registers and the SN65HVS88x series of industrial serializers that can
>>> be read over the SPI bus and used for GPI (General Purpose Input).
>>>
>>> Signed-off-by: Andrew F. Davis <afd@ti.com>
Tested-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
>>> ---
>>> drivers/gpio/Kconfig | 6 ++
>>> drivers/gpio/Makefile | 1 +
>>> drivers/gpio/gpio-pisosr.c | 188
>>> +++++++++++++++++++++++++++++++++++++++++++++
>>> 3 files changed, 195 insertions(+)
>>> create mode 100644 drivers/gpio/gpio-pisosr.c
>>>
>>> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
>>> index c88dd24..bec3489 100644
>>> --- a/drivers/gpio/Kconfig
>>> +++ b/drivers/gpio/Kconfig
>>> @@ -1011,6 +1011,12 @@ config GPIO_MC33880
>>> SPI driver for Freescale MC33880 high-side/low-side switch.
>>> This provides GPIO interface supporting inputs and outputs.
>>> +config GPIO_PISOSR
>>> + tristate "Generic parallel-in/serial-out shift register"
>>> + help
>>> + GPIO driver for SPI compatible parallel-in/serial-out shift
>>> + registers. These are input only devices.
>>> +
>>> endmenu
>>> menu "SPI or I2C GPIO expanders"
>>> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
>>> index ece7d7c..8e4f09f 100644
>>> --- a/drivers/gpio/Makefile
>>> +++ b/drivers/gpio/Makefile
>>> @@ -75,6 +75,7 @@ obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o
>>> obj-$(CONFIG_GPIO_PCA953X) += gpio-pca953x.o
>>> obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o
>>> obj-$(CONFIG_GPIO_PCH) += gpio-pch.o
>>> +obj-$(CONFIG_GPIO_PISOSR) += gpio-pisosr.o
>>> obj-$(CONFIG_GPIO_PL061) += gpio-pl061.o
>>> obj-$(CONFIG_GPIO_PXA) += gpio-pxa.o
>>> obj-$(CONFIG_GPIO_RC5T583) += gpio-rc5t583.o
>>> diff --git a/drivers/gpio/gpio-pisosr.c b/drivers/gpio/gpio-pisosr.c
>>> new file mode 100644
>>> index 0000000..58ea08d
>>> --- /dev/null
>>> +++ b/drivers/gpio/gpio-pisosr.c
>>> @@ -0,0 +1,188 @@
>>> +/*
>>> + * Copyright (C) 2015 Texas Instruments Incorporated -
>>> http://www.ti.com/
>>> + * Andrew F. Davis <afd@ti.com>
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public License
>>> version 2 as
>>> + * published by the Free Software Foundation.
>>> + *
>>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
>>> + * kind, whether expressed or implied; without even the implied
>>> warranty
>>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>>> + * GNU General Public License version 2 for more details.
>>> + */
>>> +
>>> +#include <linux/delay.h>
>>> +#include <linux/gpio/consumer.h>
>>> +#include <linux/gpio/driver.h>
>>> +#include <linux/module.h>
>>> +#include <linux/mutex.h>
>>> +#include <linux/spi/spi.h>
>>> +
>>> +#define DEFAULT_NGPIO 8
>>> +
>>> +/**
>>> + * struct pisosr_gpio - GPIO driver data
>>> + * @chip: GPIO controller chip
>>> + * @spi: SPI device pointer
>>> + * @buffer: Buffer for device reads
>>> + * @buffer_size: Size of buffer
>>> + * @load_gpio: GPIO pin used to load input into device
>>> + * @lock: Protects read sequences
>>> + */
>>> +struct pisosr_gpio {
>>> + struct gpio_chip chip;
>>> + struct spi_device *spi;
>>> + u8 *buffer;
>>> + size_t buffer_size;
>>> + struct gpio_desc *load_gpio;
>>> + struct mutex lock;
>>> +};
>>> +
>>> +static int pisosr_gpio_refresh(struct pisosr_gpio *gpio)
>>> +{
>>> + int ret;
>>> +
>>> + mutex_lock(&gpio->lock);
>>> +
>>> + if (gpio->load_gpio) {
>>> + gpiod_set_value(gpio->load_gpio, 1);
>>> + udelay(1); /* registers load time (~10ns) */
>>> + gpiod_set_value(gpio->load_gpio, 0);
>>> + udelay(1); /* registers recovery time (~5ns) */
>>> + }
>>> +
>>> + ret = spi_read(gpio->spi, gpio->buffer, gpio->buffer_size);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + mutex_unlock(&gpio->lock);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int pisosr_gpio_get_direction(struct gpio_chip *chip,
>>> + unsigned offset)
>>> +{
>>> + /* This device always input */
>>> + return 1;
>>> +}
>>> +
>>> +static int pisosr_gpio_direction_input(struct gpio_chip *chip,
>>> + unsigned offset)
>>> +{
>>> + /* This device always input */
>>> + return 0;
>>> +}
>>> +
>>> +static int pisosr_gpio_direction_output(struct gpio_chip *chip,
>>> + unsigned offset, int value)
>>> +{
>>> + /* This device is input only */
>>> + return -EINVAL;
>>> +}
>>> +
>>> +static int pisosr_gpio_get(struct gpio_chip *chip, unsigned offset)
>>> +{
>>> + struct pisosr_gpio *gpio = gpiochip_get_data(chip);
>>> +
>>> + /* Refresh may not always be needed */
>>> + pisosr_gpio_refresh(gpio);
>>> +
>>> + return (gpio->buffer[offset / 8] >> (offset % 8)) & 0x1;
>>> +}
>>> +
>>> +static struct gpio_chip template_chip = {
>>> + .label = "pisosr-gpio",
>>> + .owner = THIS_MODULE,
>>> + .get_direction = pisosr_gpio_get_direction,
>>> + .direction_input = pisosr_gpio_direction_input,
>>> + .direction_output = pisosr_gpio_direction_output,
>>> + .get = pisosr_gpio_get,
>>> + .base = -1,
>>> + .ngpio = DEFAULT_NGPIO,
>>> + .can_sleep = true,
>>> +};
>>> +
>>> +static int pisosr_gpio_probe(struct spi_device *spi)
>>> +{
>>> + struct device *dev = &spi->dev;
>>> + struct pisosr_gpio *gpio;
>>> + int ret;
>>> +
>>> + gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
>>> + if (!gpio)
>>> + return -ENOMEM;
>>> +
>>> + spi_set_drvdata(spi, gpio);
>>> +
>>> + gpio->chip = template_chip;
>>> + gpio->chip.parent = dev;
>>> + of_property_read_u16(dev->of_node, "ngpios", &gpio->chip.ngpio);
>>> +
>>> + gpio->spi = spi;
>>> +
>>> + gpio->buffer_size = DIV_ROUND_UP(gpio->chip.ngpio, 8);
>>> + gpio->buffer = devm_kzalloc(dev, gpio->buffer_size, GFP_KERNEL);
>>> + if (!gpio->buffer)
>>> + return -ENOMEM;
>>> +
>>> + gpio->load_gpio = devm_gpiod_get(dev, "load", GPIOD_OUT_LOW);
>>> + if (IS_ERR(gpio->load_gpio)) {
>>> + ret = PTR_ERR(gpio->load_gpio);
>>> + if (ret != -ENOENT && ret != -ENOSYS) {
>>> + if (ret != -EPROBE_DEFER)
>>> + dev_err(dev, "Unable to allocate load GPIO\n");
>>> + return ret;
>>> + }
>>> + gpio->load_gpio = NULL;
>>> + }
>>> +
>>> + mutex_init(&gpio->lock);
>>> +
>>> + ret = gpiochip_add_data(&gpio->chip, gpio);
>>> + if (ret < 0) {
>>> + dev_err(dev, "Unable to register gpiochip\n");
>>> + return ret;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int pisosr_gpio_remove(struct spi_device *spi)
>>> +{
>>> + struct pisosr_gpio *gpio = spi_get_drvdata(spi);
>>> +
>>> + gpiochip_remove(&gpio->chip);
>>> +
>>> + mutex_destroy(&gpio->lock);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct spi_device_id pisosr_gpio_id_table[] = {
>>> + { "pisosr-gpio", },
>>> + { /* sentinel */ }
>> Please add this :-)
>> {"ti,sn65hvs885", 0},
>
> See below.
>
>>> +};
>>> +MODULE_DEVICE_TABLE(spi, pisosr_gpio_id_table);
>>> +
>>> +static const struct of_device_id pisosr_gpio_of_match_table[] = {
>>> + { .compatible = "pisosr-gpio", },
>>> + { /* sentinel */ }
>>> +};
>>> +MODULE_DEVICE_TABLE(of, pisosr_gpio_of_match_table);
>>> +
>>> +static struct spi_driver pisosr_gpio_driver = {
>>> + .driver = {
>>> + .name = "pisosr-gpio",
>>> + .of_match_table = pisosr_gpio_of_match_table,
>>> + },
>>> + .probe = pisosr_gpio_probe,
>>> + .remove = pisosr_gpio_remove,
>>> + .id_table = pisosr_gpio_id_table,
>>> +};
>>> +module_spi_driver(pisosr_gpio_driver);
>>> +
>>> +MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
>>> +MODULE_DESCRIPTION("SPI Compatible PISO Shift Register GPIO Driver");
>>> +MODULE_LICENSE("GPL v2");
>> Hi Andrew
>>
>> I have created an driver for the sn65hvs885 at the same time as you,
>> and the output is nearly identical :-)
>> We are both missing the support for cacading devices, but i guess
>> that can come later on.
>>
>> /Sean
>
> Hi Sean,
>
> This started as a driver for the sn65hvs88*2*, after seeing other drivers
> for similar parts I found that these input shift-register devices
> interface
> mostly the same way, so a more generic catch-all driver might be more
> useful.
>
> I would like to avoid explicitly putting the individual part names
> that may be
> compatible in this driver for reasons described well by Rob's
> comment[0]. If
> you disagree I don't have any real serious qualms with adding some
> part names.
>
> Also by allowing a variable number of bits to be defined in DT I think
> cascaded devices should work with this driver already.
>
> [0] https://lkml.org/lkml/2016/1/28/581
>
> Andrew
Hi Andrew
I have tested this with 2 sn65hvs885 cacaded and i does indeed work :-)
/Sean
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^ permalink raw reply [flat|nested] 18+ messages in thread* Re: [PATCH v2 2/2] gpio: Add driver for SPI serializers
@ 2016-02-02 9:43 ` Sean Nyekjær
0 siblings, 0 replies; 18+ messages in thread
From: Sean Nyekjær @ 2016-02-02 9:43 UTC (permalink / raw)
To: Andrew F. Davis, Linus Walleij, Alexandre Courbot, Mark Brown,
Rob Herring, Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala
Cc: linux-gpio, devicetree, linux-kernel
On 2016-02-01 15:52, Andrew F. Davis wrote:
> On 01/29/2016 12:31 AM, Sean Nyekjær wrote:
>>
>>
>> On 2016-01-25 17:37, Andrew F. Davis wrote:
>>> Add generic parallel-in/serial-out shift register GPIO driver.
>>>
>>> This includes SPI compatible devices like SN74165 serial-out shift
>>> registers and the SN65HVS88x series of industrial serializers that can
>>> be read over the SPI bus and used for GPI (General Purpose Input).
>>>
>>> Signed-off-by: Andrew F. Davis <afd@ti.com>
Tested-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
>>> ---
>>> drivers/gpio/Kconfig | 6 ++
>>> drivers/gpio/Makefile | 1 +
>>> drivers/gpio/gpio-pisosr.c | 188
>>> +++++++++++++++++++++++++++++++++++++++++++++
>>> 3 files changed, 195 insertions(+)
>>> create mode 100644 drivers/gpio/gpio-pisosr.c
>>>
>>> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
>>> index c88dd24..bec3489 100644
>>> --- a/drivers/gpio/Kconfig
>>> +++ b/drivers/gpio/Kconfig
>>> @@ -1011,6 +1011,12 @@ config GPIO_MC33880
>>> SPI driver for Freescale MC33880 high-side/low-side switch.
>>> This provides GPIO interface supporting inputs and outputs.
>>> +config GPIO_PISOSR
>>> + tristate "Generic parallel-in/serial-out shift register"
>>> + help
>>> + GPIO driver for SPI compatible parallel-in/serial-out shift
>>> + registers. These are input only devices.
>>> +
>>> endmenu
>>> menu "SPI or I2C GPIO expanders"
>>> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
>>> index ece7d7c..8e4f09f 100644
>>> --- a/drivers/gpio/Makefile
>>> +++ b/drivers/gpio/Makefile
>>> @@ -75,6 +75,7 @@ obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o
>>> obj-$(CONFIG_GPIO_PCA953X) += gpio-pca953x.o
>>> obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o
>>> obj-$(CONFIG_GPIO_PCH) += gpio-pch.o
>>> +obj-$(CONFIG_GPIO_PISOSR) += gpio-pisosr.o
>>> obj-$(CONFIG_GPIO_PL061) += gpio-pl061.o
>>> obj-$(CONFIG_GPIO_PXA) += gpio-pxa.o
>>> obj-$(CONFIG_GPIO_RC5T583) += gpio-rc5t583.o
>>> diff --git a/drivers/gpio/gpio-pisosr.c b/drivers/gpio/gpio-pisosr.c
>>> new file mode 100644
>>> index 0000000..58ea08d
>>> --- /dev/null
>>> +++ b/drivers/gpio/gpio-pisosr.c
>>> @@ -0,0 +1,188 @@
>>> +/*
>>> + * Copyright (C) 2015 Texas Instruments Incorporated -
>>> http://www.ti.com/
>>> + * Andrew F. Davis <afd@ti.com>
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public License
>>> version 2 as
>>> + * published by the Free Software Foundation.
>>> + *
>>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
>>> + * kind, whether expressed or implied; without even the implied
>>> warranty
>>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>>> + * GNU General Public License version 2 for more details.
>>> + */
>>> +
>>> +#include <linux/delay.h>
>>> +#include <linux/gpio/consumer.h>
>>> +#include <linux/gpio/driver.h>
>>> +#include <linux/module.h>
>>> +#include <linux/mutex.h>
>>> +#include <linux/spi/spi.h>
>>> +
>>> +#define DEFAULT_NGPIO 8
>>> +
>>> +/**
>>> + * struct pisosr_gpio - GPIO driver data
>>> + * @chip: GPIO controller chip
>>> + * @spi: SPI device pointer
>>> + * @buffer: Buffer for device reads
>>> + * @buffer_size: Size of buffer
>>> + * @load_gpio: GPIO pin used to load input into device
>>> + * @lock: Protects read sequences
>>> + */
>>> +struct pisosr_gpio {
>>> + struct gpio_chip chip;
>>> + struct spi_device *spi;
>>> + u8 *buffer;
>>> + size_t buffer_size;
>>> + struct gpio_desc *load_gpio;
>>> + struct mutex lock;
>>> +};
>>> +
>>> +static int pisosr_gpio_refresh(struct pisosr_gpio *gpio)
>>> +{
>>> + int ret;
>>> +
>>> + mutex_lock(&gpio->lock);
>>> +
>>> + if (gpio->load_gpio) {
>>> + gpiod_set_value(gpio->load_gpio, 1);
>>> + udelay(1); /* registers load time (~10ns) */
>>> + gpiod_set_value(gpio->load_gpio, 0);
>>> + udelay(1); /* registers recovery time (~5ns) */
>>> + }
>>> +
>>> + ret = spi_read(gpio->spi, gpio->buffer, gpio->buffer_size);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + mutex_unlock(&gpio->lock);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int pisosr_gpio_get_direction(struct gpio_chip *chip,
>>> + unsigned offset)
>>> +{
>>> + /* This device always input */
>>> + return 1;
>>> +}
>>> +
>>> +static int pisosr_gpio_direction_input(struct gpio_chip *chip,
>>> + unsigned offset)
>>> +{
>>> + /* This device always input */
>>> + return 0;
>>> +}
>>> +
>>> +static int pisosr_gpio_direction_output(struct gpio_chip *chip,
>>> + unsigned offset, int value)
>>> +{
>>> + /* This device is input only */
>>> + return -EINVAL;
>>> +}
>>> +
>>> +static int pisosr_gpio_get(struct gpio_chip *chip, unsigned offset)
>>> +{
>>> + struct pisosr_gpio *gpio = gpiochip_get_data(chip);
>>> +
>>> + /* Refresh may not always be needed */
>>> + pisosr_gpio_refresh(gpio);
>>> +
>>> + return (gpio->buffer[offset / 8] >> (offset % 8)) & 0x1;
>>> +}
>>> +
>>> +static struct gpio_chip template_chip = {
>>> + .label = "pisosr-gpio",
>>> + .owner = THIS_MODULE,
>>> + .get_direction = pisosr_gpio_get_direction,
>>> + .direction_input = pisosr_gpio_direction_input,
>>> + .direction_output = pisosr_gpio_direction_output,
>>> + .get = pisosr_gpio_get,
>>> + .base = -1,
>>> + .ngpio = DEFAULT_NGPIO,
>>> + .can_sleep = true,
>>> +};
>>> +
>>> +static int pisosr_gpio_probe(struct spi_device *spi)
>>> +{
>>> + struct device *dev = &spi->dev;
>>> + struct pisosr_gpio *gpio;
>>> + int ret;
>>> +
>>> + gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
>>> + if (!gpio)
>>> + return -ENOMEM;
>>> +
>>> + spi_set_drvdata(spi, gpio);
>>> +
>>> + gpio->chip = template_chip;
>>> + gpio->chip.parent = dev;
>>> + of_property_read_u16(dev->of_node, "ngpios", &gpio->chip.ngpio);
>>> +
>>> + gpio->spi = spi;
>>> +
>>> + gpio->buffer_size = DIV_ROUND_UP(gpio->chip.ngpio, 8);
>>> + gpio->buffer = devm_kzalloc(dev, gpio->buffer_size, GFP_KERNEL);
>>> + if (!gpio->buffer)
>>> + return -ENOMEM;
>>> +
>>> + gpio->load_gpio = devm_gpiod_get(dev, "load", GPIOD_OUT_LOW);
>>> + if (IS_ERR(gpio->load_gpio)) {
>>> + ret = PTR_ERR(gpio->load_gpio);
>>> + if (ret != -ENOENT && ret != -ENOSYS) {
>>> + if (ret != -EPROBE_DEFER)
>>> + dev_err(dev, "Unable to allocate load GPIO\n");
>>> + return ret;
>>> + }
>>> + gpio->load_gpio = NULL;
>>> + }
>>> +
>>> + mutex_init(&gpio->lock);
>>> +
>>> + ret = gpiochip_add_data(&gpio->chip, gpio);
>>> + if (ret < 0) {
>>> + dev_err(dev, "Unable to register gpiochip\n");
>>> + return ret;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int pisosr_gpio_remove(struct spi_device *spi)
>>> +{
>>> + struct pisosr_gpio *gpio = spi_get_drvdata(spi);
>>> +
>>> + gpiochip_remove(&gpio->chip);
>>> +
>>> + mutex_destroy(&gpio->lock);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct spi_device_id pisosr_gpio_id_table[] = {
>>> + { "pisosr-gpio", },
>>> + { /* sentinel */ }
>> Please add this :-)
>> {"ti,sn65hvs885", 0},
>
> See below.
>
>>> +};
>>> +MODULE_DEVICE_TABLE(spi, pisosr_gpio_id_table);
>>> +
>>> +static const struct of_device_id pisosr_gpio_of_match_table[] = {
>>> + { .compatible = "pisosr-gpio", },
>>> + { /* sentinel */ }
>>> +};
>>> +MODULE_DEVICE_TABLE(of, pisosr_gpio_of_match_table);
>>> +
>>> +static struct spi_driver pisosr_gpio_driver = {
>>> + .driver = {
>>> + .name = "pisosr-gpio",
>>> + .of_match_table = pisosr_gpio_of_match_table,
>>> + },
>>> + .probe = pisosr_gpio_probe,
>>> + .remove = pisosr_gpio_remove,
>>> + .id_table = pisosr_gpio_id_table,
>>> +};
>>> +module_spi_driver(pisosr_gpio_driver);
>>> +
>>> +MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
>>> +MODULE_DESCRIPTION("SPI Compatible PISO Shift Register GPIO Driver");
>>> +MODULE_LICENSE("GPL v2");
>> Hi Andrew
>>
>> I have created an driver for the sn65hvs885 at the same time as you,
>> and the output is nearly identical :-)
>> We are both missing the support for cacading devices, but i guess
>> that can come later on.
>>
>> /Sean
>
> Hi Sean,
>
> This started as a driver for the sn65hvs88*2*, after seeing other drivers
> for similar parts I found that these input shift-register devices
> interface
> mostly the same way, so a more generic catch-all driver might be more
> useful.
>
> I would like to avoid explicitly putting the individual part names
> that may be
> compatible in this driver for reasons described well by Rob's
> comment[0]. If
> you disagree I don't have any real serious qualms with adding some
> part names.
>
> Also by allowing a variable number of bits to be defined in DT I think
> cascaded devices should work with this driver already.
>
> [0] https://lkml.org/lkml/2016/1/28/581
>
> Andrew
Hi Andrew
I have tested this with 2 sn65hvs885 cacaded and i does indeed work :-)
/Sean
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v2 2/2] gpio: Add driver for SPI serializers
2016-01-25 16:37 ` Andrew F. Davis
(?)
(?)
@ 2016-02-10 14:14 ` Linus Walleij
-1 siblings, 0 replies; 18+ messages in thread
From: Linus Walleij @ 2016-02-10 14:14 UTC (permalink / raw)
To: Andrew F. Davis
Cc: Alexandre Courbot, Mark Brown, Rob Herring, Pawel Moll,
Mark Rutland, Ian Campbell, Kumar Gala, linux-gpio, devicetree,
linux-kernel
On Mon, Jan 25, 2016 at 5:37 PM, Andrew F. Davis <afd@ti.com> wrote:
> Add generic parallel-in/serial-out shift register GPIO driver.
>
> This includes SPI compatible devices like SN74165 serial-out shift
> registers and the SN65HVS88x series of industrial serializers that can
> be read over the SPI bus and used for GPI (General Purpose Input).
>
> Signed-off-by: Andrew F. Davis <afd@ti.com>
Patch applied, good work.
Yours,
Linus Walleij
^ permalink raw reply [flat|nested] 18+ messages in thread