| Message ID | 1453739851-31839-3-git-send-email-afd@ti.com |
|---|---|
| State | New |
| Headers | show |
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 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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");
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