| Message ID | 20160823061649.3394-2-vigneshr@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 08/23/2016 01:16 AM, Vignesh R wrote: > Add a driver to read group of GPIO lines and provide its status as a > numerical value as input event to the system. This will help in > intefacing devices, that can be connected over GPIOs, that provide input > to the system by driving GPIO lines connected to them like a rotary dial > or a switch. > > For example, a rotary switch can be connected to four GPIO lines. The > status of the GPIO lines reflect the actual position of the rotary > switch dial. For example, if dial points to 9, then the four GPIO lines > connected to the switch will read HLLH(0b'1001 = 9). This value > can be reported as an ABS_* event to the input subsystem. > > Signed-off-by: Vignesh R <vigneshr@ti.com> > Acked-by: Rob Herring <robh@kernel.org> > --- > > v2: Use decoder,max-value instead of gpio-decoder,max-value. > > .../devicetree/bindings/input/gpio-decoder.txt | 23 ++++ > drivers/input/misc/Kconfig | 12 ++ > drivers/input/misc/Makefile | 1 + > drivers/input/misc/gpio_decoder.c | 130 +++++++++++++++++++++ > 4 files changed, 166 insertions(+) > create mode 100644 Documentation/devicetree/bindings/input/gpio-decoder.txt > create mode 100644 drivers/input/misc/gpio_decoder.c > > diff --git a/Documentation/devicetree/bindings/input/gpio-decoder.txt b/Documentation/devicetree/bindings/input/gpio-decoder.txt > new file mode 100644 > index 000000000000..f27f083a9075 > --- /dev/null > +++ b/Documentation/devicetree/bindings/input/gpio-decoder.txt > @@ -0,0 +1,23 @@ > +* GPIO Decoder DT bindings > + > +Required Properties: > +- compatible: should be "gpio-decoder" > +- gpios: a spec of gpios (atleast two) to be decoded to a number with ^^ two words > + first entry representing the MSB. > + > +Optional Properties: > +- decoder,max-value: Maximum possible value that can be reported by > + the gpios. > +- linux,axis: the input subsystem axis to map to (ABS_X/ABS_Y). > + Defaults to 0 (ABS_X). > + > +Example: > + gpio-decoder0 { > + compatible = "gpio-decoder"; > + gpios = <&pca9536 3 GPIO_ACTIVE_HIGH>, > + <&pca9536 2 GPIO_ACTIVE_HIGH>, > + <&pca9536 1 GPIO_ACTIVE_HIGH>, > + <&pca9536 0 GPIO_ACTIVE_HIGH>; > + linux,axis = <0>; /* ABS_X */ > + decoder,max-value = <9>; > + }; > diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig > index efb0ca871327..c44513cac3b7 100644 > --- a/drivers/input/misc/Kconfig > +++ b/drivers/input/misc/Kconfig > @@ -292,6 +292,18 @@ config INPUT_GPIO_TILT_POLLED > To compile this driver as a module, choose M here: the > module will be called gpio_tilt_polled. > > +config INPUT_GPIO_DECODER > + tristate "Polled GPIO Decoder Input driver" > + depends on GPIOLIB && OF > + select INPUT_POLLDEV > + help > + Say Y here if you want driver to read status of multiple GPIO > + lines and report the encoded value as an absolute integer to > + input subsystem. > + > + To compile this driver as a module, choose M here: the module > + will will be called gpio_decoder. > + > config INPUT_IXP4XX_BEEPER > tristate "IXP4XX Beeper support" > depends on ARCH_IXP4XX > diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile > index 6a1e5e20fc1c..0b6d025f0487 100644 > --- a/drivers/input/misc/Makefile > +++ b/drivers/input/misc/Makefile > @@ -35,6 +35,7 @@ obj-$(CONFIG_INPUT_DRV2667_HAPTICS) += drv2667.o > obj-$(CONFIG_INPUT_GP2A) += gp2ap002a00f.o > obj-$(CONFIG_INPUT_GPIO_BEEPER) += gpio-beeper.o > obj-$(CONFIG_INPUT_GPIO_TILT_POLLED) += gpio_tilt_polled.o > +obj-$(CONFIG_INPUT_GPIO_DECODER) += gpio_decoder.o > obj-$(CONFIG_INPUT_HISI_POWERKEY) += hisi_powerkey.o > obj-$(CONFIG_HP_SDC_RTC) += hp_sdc_rtc.o > obj-$(CONFIG_INPUT_IMS_PCU) += ims-pcu.o > diff --git a/drivers/input/misc/gpio_decoder.c b/drivers/input/misc/gpio_decoder.c > new file mode 100644 > index 000000000000..eec0fda6f562 > --- /dev/null > +++ b/drivers/input/misc/gpio_decoder.c > @@ -0,0 +1,130 @@ > +/* > + * gpio-decoder.c > + * ^ the name of the file often changes without this being updated, it really doesn't add anything anyway, would recommend dropping it. > + * A generic driver to reads multiple gpio lines and translate the > + * encoded numeric value into an input event. > + * > + * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/ > + * > + * 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 version 2. > + * > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any > + * kind, whether express or implied; without even the implied warranty > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include <linux/device.h> > +#include <linux/gpio/consumer.h> > +#include <linux/input.h> > +#include <linux/input-polldev.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > + > +struct gpio_decoder { > + struct input_polled_dev *poll_dev; > + struct gpio_descs *input_gpios; > + struct device *dev; > + u32 axis; > + u32 last_stable; > +}; > + > +static unsigned int gpio_decoder_get_gpios_state(struct gpio_decoder > + *decoder) > +{ > + struct gpio_descs *gpios = decoder->input_gpios; > + unsigned int ret = 0; > + int i, val; > + > + for (i = 0; i < gpios->ndescs; i++) { > + val = gpiod_get_value_cansleep(gpios->desc[i]); > + ret = ret << 1 | val; Just to be safe, could you mask val with 0x1 here. > + } > + > + return ret; > +} > + > +static void gpio_decoder_poll_gpios(struct input_polled_dev *poll_dev) > +{ > + struct gpio_decoder *decoder = poll_dev->private; > + unsigned int state = gpio_decoder_get_gpios_state(decoder); > + > + if (state != decoder->last_stable) { > + input_report_abs(poll_dev->input, decoder->axis, state); > + input_sync(poll_dev->input); > + decoder->last_stable = state; > + } > +} > + > +static int gpio_decoder_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct gpio_decoder *decoder; > + struct input_polled_dev *poll_dev; > + u32 max; > + int err; > + > + decoder = devm_kzalloc(dev, sizeof(struct gpio_decoder), GFP_KERNEL); > + if (!decoder) > + return -ENOMEM; > + > + device_property_read_u32(dev, "linux,axis", &decoder->axis); > + decoder->input_gpios = devm_gpiod_get_array(dev, NULL, GPIOD_IN); > + if (IS_ERR(decoder->input_gpios)) { > + dev_err(dev, "unable to acquire input gpios\n"); > + return PTR_ERR(decoder->input_gpios); > + } > + if (decoder->input_gpios->ndescs < 2) { > + dev_err(dev, "not enough gpios found\n"); > + return -EINVAL; > + } > + > + if (device_property_read_u32(dev, "decoder,max-value", &max)) > + max = BIT(decoder->input_gpios->ndescs); > + > + decoder->dev = dev; > + poll_dev = devm_input_allocate_polled_device(decoder->dev); > + if (!poll_dev) > + return -ENOMEM; > + > + poll_dev->private = decoder; > + poll_dev->poll = gpio_decoder_poll_gpios; > + decoder->poll_dev = poll_dev; > + > + poll_dev->input->name = pdev->name; > + poll_dev->input->id.bustype = BUS_HOST; > + poll_dev->input->dev.parent = dev; > + input_set_abs_params(poll_dev->input, decoder->axis, 0, max, 0, 1); > + > + err = input_register_polled_device(poll_dev); > + if (err) { > + dev_err(dev, "failed to register polled device\n"); > + return err; > + } > + platform_set_drvdata(pdev, decoder); > + > + return 0; > +} > + > +static const struct of_device_id gpio_decoder_of_match[] = { > + { .compatible = "gpio-decoder", }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, gpio_decoder_of_match); > + > +static struct platform_driver gpio_decoder_driver = { > + .probe = gpio_decoder_probe, > + .driver = { > + .name = "gpio-decoder", > + .of_match_table = of_match_ptr(gpio_decoder_of_match), When the struct 'gpio_decoder_of_match' is always defined (not conditional on OF support), then 'of_match_ptr' does nothing and can be dropped here. > + } > +}; > +module_platform_driver(gpio_decoder_driver); > + > +MODULE_DESCRIPTION("GPIO decoder input driver"); > +MODULE_AUTHOR("Vignesh R <vigneshr@ti.com>"); > +MODULE_LICENSE("GPL v2"); -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Aug 23, 2016 at 10:27:59AM -0500, Andrew F. Davis wrote: > On 08/23/2016 01:16 AM, Vignesh R wrote: > > Add a driver to read group of GPIO lines and provide its status as a > > numerical value as input event to the system. This will help in > > intefacing devices, that can be connected over GPIOs, that provide input > > to the system by driving GPIO lines connected to them like a rotary dial > > or a switch. > > > > For example, a rotary switch can be connected to four GPIO lines. The > > status of the GPIO lines reflect the actual position of the rotary > > switch dial. For example, if dial points to 9, then the four GPIO lines > > connected to the switch will read HLLH(0b'1001 = 9). This value > > can be reported as an ABS_* event to the input subsystem. > > > > Signed-off-by: Vignesh R <vigneshr@ti.com> > > Acked-by: Rob Herring <robh@kernel.org> > > --- > > > > v2: Use decoder,max-value instead of gpio-decoder,max-value. > > > > .../devicetree/bindings/input/gpio-decoder.txt | 23 ++++ > > drivers/input/misc/Kconfig | 12 ++ > > drivers/input/misc/Makefile | 1 + > > drivers/input/misc/gpio_decoder.c | 130 +++++++++++++++++++++ > > 4 files changed, 166 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/input/gpio-decoder.txt > > create mode 100644 drivers/input/misc/gpio_decoder.c > > > > diff --git a/Documentation/devicetree/bindings/input/gpio-decoder.txt b/Documentation/devicetree/bindings/input/gpio-decoder.txt > > new file mode 100644 > > index 000000000000..f27f083a9075 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/input/gpio-decoder.txt > > @@ -0,0 +1,23 @@ > > +* GPIO Decoder DT bindings > > + > > +Required Properties: > > +- compatible: should be "gpio-decoder" > > +- gpios: a spec of gpios (atleast two) to be decoded to a number with > > ^^ two words > > > + first entry representing the MSB. > > + > > +Optional Properties: > > +- decoder,max-value: Maximum possible value that can be reported by > > + the gpios. > > +- linux,axis: the input subsystem axis to map to (ABS_X/ABS_Y). > > + Defaults to 0 (ABS_X). > > + > > +Example: > > + gpio-decoder0 { > > + compatible = "gpio-decoder"; > > + gpios = <&pca9536 3 GPIO_ACTIVE_HIGH>, > > + <&pca9536 2 GPIO_ACTIVE_HIGH>, > > + <&pca9536 1 GPIO_ACTIVE_HIGH>, > > + <&pca9536 0 GPIO_ACTIVE_HIGH>; > > + linux,axis = <0>; /* ABS_X */ > > + decoder,max-value = <9>; > > + }; > > diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig > > index efb0ca871327..c44513cac3b7 100644 > > --- a/drivers/input/misc/Kconfig > > +++ b/drivers/input/misc/Kconfig > > @@ -292,6 +292,18 @@ config INPUT_GPIO_TILT_POLLED > > To compile this driver as a module, choose M here: the > > module will be called gpio_tilt_polled. > > > > +config INPUT_GPIO_DECODER > > + tristate "Polled GPIO Decoder Input driver" > > + depends on GPIOLIB && OF > > + select INPUT_POLLDEV > > + help > > + Say Y here if you want driver to read status of multiple GPIO > > + lines and report the encoded value as an absolute integer to > > + input subsystem. > > + > > + To compile this driver as a module, choose M here: the module > > + will will be called gpio_decoder. > > + > > config INPUT_IXP4XX_BEEPER > > tristate "IXP4XX Beeper support" > > depends on ARCH_IXP4XX > > diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile > > index 6a1e5e20fc1c..0b6d025f0487 100644 > > --- a/drivers/input/misc/Makefile > > +++ b/drivers/input/misc/Makefile > > @@ -35,6 +35,7 @@ obj-$(CONFIG_INPUT_DRV2667_HAPTICS) += drv2667.o > > obj-$(CONFIG_INPUT_GP2A) += gp2ap002a00f.o > > obj-$(CONFIG_INPUT_GPIO_BEEPER) += gpio-beeper.o > > obj-$(CONFIG_INPUT_GPIO_TILT_POLLED) += gpio_tilt_polled.o > > +obj-$(CONFIG_INPUT_GPIO_DECODER) += gpio_decoder.o > > obj-$(CONFIG_INPUT_HISI_POWERKEY) += hisi_powerkey.o > > obj-$(CONFIG_HP_SDC_RTC) += hp_sdc_rtc.o > > obj-$(CONFIG_INPUT_IMS_PCU) += ims-pcu.o > > diff --git a/drivers/input/misc/gpio_decoder.c b/drivers/input/misc/gpio_decoder.c > > new file mode 100644 > > index 000000000000..eec0fda6f562 > > --- /dev/null > > +++ b/drivers/input/misc/gpio_decoder.c > > @@ -0,0 +1,130 @@ > > +/* > > + * gpio-decoder.c > > + * > > ^ the name of the file often changes without this being updated, it > really doesn't add anything anyway, would recommend dropping it. > > > + * A generic driver to reads multiple gpio lines and translate the > > + * encoded numeric value into an input event. > > + * > > + * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/ > > + * > > + * 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 version 2. > > + * > > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any > > + * kind, whether express or implied; without even the implied warranty > > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > + * GNU General Public License for more details. > > + */ > > + > > +#include <linux/device.h> > > +#include <linux/gpio/consumer.h> > > +#include <linux/input.h> > > +#include <linux/input-polldev.h> > > +#include <linux/kernel.h> > > +#include <linux/module.h> > > +#include <linux/of.h> > > +#include <linux/platform_device.h> > > + > > +struct gpio_decoder { > > + struct input_polled_dev *poll_dev; > > + struct gpio_descs *input_gpios; > > + struct device *dev; > > + u32 axis; > > + u32 last_stable; > > +}; > > + > > +static unsigned int gpio_decoder_get_gpios_state(struct gpio_decoder > > + *decoder) > > +{ > > + struct gpio_descs *gpios = decoder->input_gpios; > > + unsigned int ret = 0; > > + int i, val; > > + > > + for (i = 0; i < gpios->ndescs; i++) { > > + val = gpiod_get_value_cansleep(gpios->desc[i]); > > + ret = ret << 1 | val; > > Just to be safe, could you mask val with 0x1 here. We also want to check for negative. So I guess: val = gpiod_get_value_cansleep(gpios->desc[i]); if (val >= 0) ret = (ret << 1) | !!val; ? > > > + } > > + > > + return ret; > > +} > > + > > +static void gpio_decoder_poll_gpios(struct input_polled_dev *poll_dev) > > +{ > > + struct gpio_decoder *decoder = poll_dev->private; > > + unsigned int state = gpio_decoder_get_gpios_state(decoder); > > + > > + if (state != decoder->last_stable) { > > + input_report_abs(poll_dev->input, decoder->axis, state); > > + input_sync(poll_dev->input); > > + decoder->last_stable = state; > > + } > > +} > > + > > +static int gpio_decoder_probe(struct platform_device *pdev) > > +{ > > + struct device *dev = &pdev->dev; > > + struct gpio_decoder *decoder; > > + struct input_polled_dev *poll_dev; > > + u32 max; > > + int err; > > + > > + decoder = devm_kzalloc(dev, sizeof(struct gpio_decoder), GFP_KERNEL); > > + if (!decoder) > > + return -ENOMEM; > > + > > + device_property_read_u32(dev, "linux,axis", &decoder->axis); > > + decoder->input_gpios = devm_gpiod_get_array(dev, NULL, GPIOD_IN); > > + if (IS_ERR(decoder->input_gpios)) { > > + dev_err(dev, "unable to acquire input gpios\n"); > > + return PTR_ERR(decoder->input_gpios); > > + } > > + if (decoder->input_gpios->ndescs < 2) { > > + dev_err(dev, "not enough gpios found\n"); > > + return -EINVAL; > > + } > > + > > + if (device_property_read_u32(dev, "decoder,max-value", &max)) > > + max = BIT(decoder->input_gpios->ndescs); > > + > > + decoder->dev = dev; > > + poll_dev = devm_input_allocate_polled_device(decoder->dev); > > + if (!poll_dev) > > + return -ENOMEM; > > + > > + poll_dev->private = decoder; > > + poll_dev->poll = gpio_decoder_poll_gpios; > > + decoder->poll_dev = poll_dev; > > + > > + poll_dev->input->name = pdev->name; > > + poll_dev->input->id.bustype = BUS_HOST; > > + poll_dev->input->dev.parent = dev; No need to set for devices allocated with devm_input_allocate_polled_device. > > + input_set_abs_params(poll_dev->input, decoder->axis, 0, max, 0, 1); > > + > > + err = input_register_polled_device(poll_dev); > > + if (err) { > > + dev_err(dev, "failed to register polled device\n"); > > + return err; > > + } > > + platform_set_drvdata(pdev, decoder); > > + > > + return 0; > > +} > > + > > +static const struct of_device_id gpio_decoder_of_match[] = { > > + { .compatible = "gpio-decoder", }, > > + { }, > > +}; > > +MODULE_DEVICE_TABLE(of, gpio_decoder_of_match); > > + > > +static struct platform_driver gpio_decoder_driver = { > > + .probe = gpio_decoder_probe, > > + .driver = { > > + .name = "gpio-decoder", > > + .of_match_table = of_match_ptr(gpio_decoder_of_match), > > When the struct 'gpio_decoder_of_match' is always defined (not > conditional on OF support), then 'of_match_ptr' does nothing and can be > dropped here. There is nothing in this driver that makes it OF-specific. I'd leave of_match_ptr() as is, added #ifdef CONFIG_OF guard around gpio_decoder_of_match, and changed "depends on GPIOLIB && OF" to "depends on GPIOLIB || COMPILE_TEST". Thanks. > > > + } > > +}; > > +module_platform_driver(gpio_decoder_driver); > > + > > +MODULE_DESCRIPTION("GPIO decoder input driver"); > > +MODULE_AUTHOR("Vignesh R <vigneshr@ti.com>"); > > +MODULE_LICENSE("GPL v2");
On Tue, Aug 23, 2016 at 10:27:59AM -0500, Andrew F. Davis wrote: > On 08/23/2016 01:16 AM, Vignesh R wrote: > > Add a driver to read group of GPIO lines and provide its status as a > > numerical value as input event to the system. This will help in > > intefacing devices, that can be connected over GPIOs, that provide input > > to the system by driving GPIO lines connected to them like a rotary dial > > or a switch. > > > > For example, a rotary switch can be connected to four GPIO lines. The > > status of the GPIO lines reflect the actual position of the rotary > > switch dial. For example, if dial points to 9, then the four GPIO lines > > connected to the switch will read HLLH(0b'1001 = 9). This value > > can be reported as an ABS_* event to the input subsystem. > > > > Signed-off-by: Vignesh R <vigneshr@ti.com> > > Acked-by: Rob Herring <robh@kernel.org> > > --- > > > > v2: Use decoder,max-value instead of gpio-decoder,max-value. That's not what Rob asked for. "decoder-max-value", not "decoder" vendor prefix. Thanks.
Hi Andrew, Dmitry, On Wednesday 24 August 2016 01:31 AM, Dmitry Torokhov wrote: > On Tue, Aug 23, 2016 at 10:27:59AM -0500, Andrew F. Davis wrote: >> On 08/23/2016 01:16 AM, Vignesh R wrote: >>> Add a driver to read group of GPIO lines and provide its status as a >>> numerical value as input event to the system. This will help in >>> intefacing devices, that can be connected over GPIOs, that provide input >>> to the system by driving GPIO lines connected to them like a rotary dial >>> or a switch. >>> >>> For example, a rotary switch can be connected to four GPIO lines. The >>> status of the GPIO lines reflect the actual position of the rotary >>> switch dial. For example, if dial points to 9, then the four GPIO lines >>> connected to the switch will read HLLH(0b'1001 = 9). This value >>> can be reported as an ABS_* event to the input subsystem. >>> >>> Signed-off-by: Vignesh R <vigneshr@ti.com> >>> Acked-by: Rob Herring <robh@kernel.org> >>> --- >>> >>> v2: Use decoder,max-value instead of gpio-decoder,max-value. >>> >>> .../devicetree/bindings/input/gpio-decoder.txt | 23 ++++ >>> drivers/input/misc/Kconfig | 12 ++ >>> drivers/input/misc/Makefile | 1 + >>> drivers/input/misc/gpio_decoder.c | 130 +++++++++++++++++++++ >>> 4 files changed, 166 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/input/gpio-decoder.txt >>> create mode 100644 drivers/input/misc/gpio_decoder.c >>> >>> diff --git a/Documentation/devicetree/bindings/input/gpio-decoder.txt b/Documentation/devicetree/bindings/input/gpio-decoder.txt >>> new file mode 100644 >>> index 000000000000..f27f083a9075 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/input/gpio-decoder.txt >>> @@ -0,0 +1,23 @@ >>> +* GPIO Decoder DT bindings >>> + >>> +Required Properties: >>> +- compatible: should be "gpio-decoder" >>> +- gpios: a spec of gpios (atleast two) to be decoded to a number with >> >> ^^ two words Ok. >> >>> + first entry representing the MSB. >>> + >>> +Optional Properties: >>> +- decoder,max-value: Maximum possible value that can be reported by >>> + the gpios. I will change this to decoder-max-value as suggested previously. >>> +- linux,axis: the input subsystem axis to map to (ABS_X/ABS_Y). >>> + Defaults to 0 (ABS_X). >>> + >>> +Example: >>> + gpio-decoder0 { >>> + compatible = "gpio-decoder"; >>> + gpios = <&pca9536 3 GPIO_ACTIVE_HIGH>, >>> + <&pca9536 2 GPIO_ACTIVE_HIGH>, >>> + <&pca9536 1 GPIO_ACTIVE_HIGH>, >>> + <&pca9536 0 GPIO_ACTIVE_HIGH>; >>> + linux,axis = <0>; /* ABS_X */ >>> + decoder,max-value = <9>; >>> + }; >>> diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig >>> index efb0ca871327..c44513cac3b7 100644 >>> --- a/drivers/input/misc/Kconfig >>> +++ b/drivers/input/misc/Kconfig >>> @@ -292,6 +292,18 @@ config INPUT_GPIO_TILT_POLLED >>> To compile this driver as a module, choose M here: the >>> module will be called gpio_tilt_polled. >>> >>> +config INPUT_GPIO_DECODER >>> + tristate "Polled GPIO Decoder Input driver" >>> + depends on GPIOLIB && OF >>> + select INPUT_POLLDEV >>> + help >>> + Say Y here if you want driver to read status of multiple GPIO >>> + lines and report the encoded value as an absolute integer to >>> + input subsystem. >>> + >>> + To compile this driver as a module, choose M here: the module >>> + will will be called gpio_decoder. >>> + >>> config INPUT_IXP4XX_BEEPER >>> tristate "IXP4XX Beeper support" >>> depends on ARCH_IXP4XX >>> diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile >>> index 6a1e5e20fc1c..0b6d025f0487 100644 >>> --- a/drivers/input/misc/Makefile >>> +++ b/drivers/input/misc/Makefile >>> @@ -35,6 +35,7 @@ obj-$(CONFIG_INPUT_DRV2667_HAPTICS) += drv2667.o >>> obj-$(CONFIG_INPUT_GP2A) += gp2ap002a00f.o >>> obj-$(CONFIG_INPUT_GPIO_BEEPER) += gpio-beeper.o >>> obj-$(CONFIG_INPUT_GPIO_TILT_POLLED) += gpio_tilt_polled.o >>> +obj-$(CONFIG_INPUT_GPIO_DECODER) += gpio_decoder.o >>> obj-$(CONFIG_INPUT_HISI_POWERKEY) += hisi_powerkey.o >>> obj-$(CONFIG_HP_SDC_RTC) += hp_sdc_rtc.o >>> obj-$(CONFIG_INPUT_IMS_PCU) += ims-pcu.o >>> diff --git a/drivers/input/misc/gpio_decoder.c b/drivers/input/misc/gpio_decoder.c >>> new file mode 100644 >>> index 000000000000..eec0fda6f562 >>> --- /dev/null >>> +++ b/drivers/input/misc/gpio_decoder.c >>> @@ -0,0 +1,130 @@ >>> +/* >>> + * gpio-decoder.c >>> + * >> >> ^ the name of the file often changes without this being updated, it >> really doesn't add anything anyway, would recommend dropping it. Ok. >> >>> + * A generic driver to reads multiple gpio lines and translate the >>> + * encoded numeric value into an input event. >>> + * >>> + * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/ >>> + * >>> + * 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 version 2. >>> + * >>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any >>> + * kind, whether express or implied; without even the implied warranty >>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >>> + * GNU General Public License for more details. >>> + */ >>> + >>> +#include <linux/device.h> >>> +#include <linux/gpio/consumer.h> >>> +#include <linux/input.h> >>> +#include <linux/input-polldev.h> >>> +#include <linux/kernel.h> >>> +#include <linux/module.h> >>> +#include <linux/of.h> >>> +#include <linux/platform_device.h> >>> + >>> +struct gpio_decoder { >>> + struct input_polled_dev *poll_dev; >>> + struct gpio_descs *input_gpios; >>> + struct device *dev; >>> + u32 axis; >>> + u32 last_stable; >>> +}; >>> + >>> +static unsigned int gpio_decoder_get_gpios_state(struct gpio_decoder >>> + *decoder) >>> +{ >>> + struct gpio_descs *gpios = decoder->input_gpios; >>> + unsigned int ret = 0; >>> + int i, val; >>> + >>> + for (i = 0; i < gpios->ndescs; i++) { >>> + val = gpiod_get_value_cansleep(gpios->desc[i]); >>> + ret = ret << 1 | val; >> >> Just to be safe, could you mask val with 0x1 here. > > We also want to check for negative. So I guess: > > val = gpiod_get_value_cansleep(gpios->desc[i]); > if (val >= 0) > ret = (ret << 1) | !!val; > > ? Agreed. > >> >>> + } >>> + >>> + return ret; >>> +} >>> + >>> +static void gpio_decoder_poll_gpios(struct input_polled_dev *poll_dev) >>> +{ >>> + struct gpio_decoder *decoder = poll_dev->private; >>> + unsigned int state = gpio_decoder_get_gpios_state(decoder); >>> + >>> + if (state != decoder->last_stable) { >>> + input_report_abs(poll_dev->input, decoder->axis, state); >>> + input_sync(poll_dev->input); >>> + decoder->last_stable = state; >>> + } >>> +} >>> + >>> +static int gpio_decoder_probe(struct platform_device *pdev) >>> +{ >>> + struct device *dev = &pdev->dev; >>> + struct gpio_decoder *decoder; >>> + struct input_polled_dev *poll_dev; >>> + u32 max; >>> + int err; >>> + >>> + decoder = devm_kzalloc(dev, sizeof(struct gpio_decoder), GFP_KERNEL); >>> + if (!decoder) >>> + return -ENOMEM; >>> + >>> + device_property_read_u32(dev, "linux,axis", &decoder->axis); >>> + decoder->input_gpios = devm_gpiod_get_array(dev, NULL, GPIOD_IN); >>> + if (IS_ERR(decoder->input_gpios)) { >>> + dev_err(dev, "unable to acquire input gpios\n"); >>> + return PTR_ERR(decoder->input_gpios); >>> + } >>> + if (decoder->input_gpios->ndescs < 2) { >>> + dev_err(dev, "not enough gpios found\n"); >>> + return -EINVAL; >>> + } >>> + >>> + if (device_property_read_u32(dev, "decoder,max-value", &max)) >>> + max = BIT(decoder->input_gpios->ndescs); >>> + >>> + decoder->dev = dev; >>> + poll_dev = devm_input_allocate_polled_device(decoder->dev); >>> + if (!poll_dev) >>> + return -ENOMEM; >>> + >>> + poll_dev->private = decoder; >>> + poll_dev->poll = gpio_decoder_poll_gpios; >>> + decoder->poll_dev = poll_dev; >>> + >>> + poll_dev->input->name = pdev->name; >>> + poll_dev->input->id.bustype = BUS_HOST; >>> + poll_dev->input->dev.parent = dev; > > No need to set for devices allocated with > devm_input_allocate_polled_device. Will drop this. > >>> + input_set_abs_params(poll_dev->input, decoder->axis, 0, max, 0, 1); >>> + >>> + err = input_register_polled_device(poll_dev); >>> + if (err) { >>> + dev_err(dev, "failed to register polled device\n"); >>> + return err; >>> + } >>> + platform_set_drvdata(pdev, decoder); >>> + >>> + return 0; >>> +} >>> + >>> +static const struct of_device_id gpio_decoder_of_match[] = { >>> + { .compatible = "gpio-decoder", }, >>> + { }, >>> +}; >>> +MODULE_DEVICE_TABLE(of, gpio_decoder_of_match); >>> + >>> +static struct platform_driver gpio_decoder_driver = { >>> + .probe = gpio_decoder_probe, >>> + .driver = { >>> + .name = "gpio-decoder", >>> + .of_match_table = of_match_ptr(gpio_decoder_of_match), >> >> When the struct 'gpio_decoder_of_match' is always defined (not >> conditional on OF support), then 'of_match_ptr' does nothing and can be >> dropped here. > > There is nothing in this driver that makes it OF-specific. I'd leave > of_match_ptr() as is, added #ifdef CONFIG_OF guard around > gpio_decoder_of_match, >and changed "depends on GPIOLIB && OF" to "depends on GPIOLIB || COMPILE_TEST". > Agreed. Thanks for the review!
On Wednesday 24 August 2016 01:33 AM, Dmitry Torokhov wrote: > On Tue, Aug 23, 2016 at 10:27:59AM -0500, Andrew F. Davis wrote: >> On 08/23/2016 01:16 AM, Vignesh R wrote: >>> Add a driver to read group of GPIO lines and provide its status as a >>> numerical value as input event to the system. This will help in >>> intefacing devices, that can be connected over GPIOs, that provide input >>> to the system by driving GPIO lines connected to them like a rotary dial >>> or a switch. >>> >>> For example, a rotary switch can be connected to four GPIO lines. The >>> status of the GPIO lines reflect the actual position of the rotary >>> switch dial. For example, if dial points to 9, then the four GPIO lines >>> connected to the switch will read HLLH(0b'1001 = 9). This value >>> can be reported as an ABS_* event to the input subsystem. >>> >>> Signed-off-by: Vignesh R <vigneshr@ti.com> >>> Acked-by: Rob Herring <robh@kernel.org> >>> --- >>> >>> v2: Use decoder,max-value instead of gpio-decoder,max-value. > > That's not what Rob asked for. "decoder-max-value", not "decoder" vendor > prefix. > Sorry.. Will fix this in v3.
diff --git a/Documentation/devicetree/bindings/input/gpio-decoder.txt b/Documentation/devicetree/bindings/input/gpio-decoder.txt new file mode 100644 index 000000000000..f27f083a9075 --- /dev/null +++ b/Documentation/devicetree/bindings/input/gpio-decoder.txt @@ -0,0 +1,23 @@ +* GPIO Decoder DT bindings + +Required Properties: +- compatible: should be "gpio-decoder" +- gpios: a spec of gpios (atleast two) to be decoded to a number with + first entry representing the MSB. + +Optional Properties: +- decoder,max-value: Maximum possible value that can be reported by + the gpios. +- linux,axis: the input subsystem axis to map to (ABS_X/ABS_Y). + Defaults to 0 (ABS_X). + +Example: + gpio-decoder0 { + compatible = "gpio-decoder"; + gpios = <&pca9536 3 GPIO_ACTIVE_HIGH>, + <&pca9536 2 GPIO_ACTIVE_HIGH>, + <&pca9536 1 GPIO_ACTIVE_HIGH>, + <&pca9536 0 GPIO_ACTIVE_HIGH>; + linux,axis = <0>; /* ABS_X */ + decoder,max-value = <9>; + }; diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig index efb0ca871327..c44513cac3b7 100644 --- a/drivers/input/misc/Kconfig +++ b/drivers/input/misc/Kconfig @@ -292,6 +292,18 @@ config INPUT_GPIO_TILT_POLLED To compile this driver as a module, choose M here: the module will be called gpio_tilt_polled. +config INPUT_GPIO_DECODER + tristate "Polled GPIO Decoder Input driver" + depends on GPIOLIB && OF + select INPUT_POLLDEV + help + Say Y here if you want driver to read status of multiple GPIO + lines and report the encoded value as an absolute integer to + input subsystem. + + To compile this driver as a module, choose M here: the module + will will be called gpio_decoder. + config INPUT_IXP4XX_BEEPER tristate "IXP4XX Beeper support" depends on ARCH_IXP4XX diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile index 6a1e5e20fc1c..0b6d025f0487 100644 --- a/drivers/input/misc/Makefile +++ b/drivers/input/misc/Makefile @@ -35,6 +35,7 @@ obj-$(CONFIG_INPUT_DRV2667_HAPTICS) += drv2667.o obj-$(CONFIG_INPUT_GP2A) += gp2ap002a00f.o obj-$(CONFIG_INPUT_GPIO_BEEPER) += gpio-beeper.o obj-$(CONFIG_INPUT_GPIO_TILT_POLLED) += gpio_tilt_polled.o +obj-$(CONFIG_INPUT_GPIO_DECODER) += gpio_decoder.o obj-$(CONFIG_INPUT_HISI_POWERKEY) += hisi_powerkey.o obj-$(CONFIG_HP_SDC_RTC) += hp_sdc_rtc.o obj-$(CONFIG_INPUT_IMS_PCU) += ims-pcu.o diff --git a/drivers/input/misc/gpio_decoder.c b/drivers/input/misc/gpio_decoder.c new file mode 100644 index 000000000000..eec0fda6f562 --- /dev/null +++ b/drivers/input/misc/gpio_decoder.c @@ -0,0 +1,130 @@ +/* + * gpio-decoder.c + * + * A generic driver to reads multiple gpio lines and translate the + * encoded numeric value into an input event. + * + * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/ + * + * 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 version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/device.h> +#include <linux/gpio/consumer.h> +#include <linux/input.h> +#include <linux/input-polldev.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> + +struct gpio_decoder { + struct input_polled_dev *poll_dev; + struct gpio_descs *input_gpios; + struct device *dev; + u32 axis; + u32 last_stable; +}; + +static unsigned int gpio_decoder_get_gpios_state(struct gpio_decoder + *decoder) +{ + struct gpio_descs *gpios = decoder->input_gpios; + unsigned int ret = 0; + int i, val; + + for (i = 0; i < gpios->ndescs; i++) { + val = gpiod_get_value_cansleep(gpios->desc[i]); + ret = ret << 1 | val; + } + + return ret; +} + +static void gpio_decoder_poll_gpios(struct input_polled_dev *poll_dev) +{ + struct gpio_decoder *decoder = poll_dev->private; + unsigned int state = gpio_decoder_get_gpios_state(decoder); + + if (state != decoder->last_stable) { + input_report_abs(poll_dev->input, decoder->axis, state); + input_sync(poll_dev->input); + decoder->last_stable = state; + } +} + +static int gpio_decoder_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct gpio_decoder *decoder; + struct input_polled_dev *poll_dev; + u32 max; + int err; + + decoder = devm_kzalloc(dev, sizeof(struct gpio_decoder), GFP_KERNEL); + if (!decoder) + return -ENOMEM; + + device_property_read_u32(dev, "linux,axis", &decoder->axis); + decoder->input_gpios = devm_gpiod_get_array(dev, NULL, GPIOD_IN); + if (IS_ERR(decoder->input_gpios)) { + dev_err(dev, "unable to acquire input gpios\n"); + return PTR_ERR(decoder->input_gpios); + } + if (decoder->input_gpios->ndescs < 2) { + dev_err(dev, "not enough gpios found\n"); + return -EINVAL; + } + + if (device_property_read_u32(dev, "decoder,max-value", &max)) + max = BIT(decoder->input_gpios->ndescs); + + decoder->dev = dev; + poll_dev = devm_input_allocate_polled_device(decoder->dev); + if (!poll_dev) + return -ENOMEM; + + poll_dev->private = decoder; + poll_dev->poll = gpio_decoder_poll_gpios; + decoder->poll_dev = poll_dev; + + poll_dev->input->name = pdev->name; + poll_dev->input->id.bustype = BUS_HOST; + poll_dev->input->dev.parent = dev; + input_set_abs_params(poll_dev->input, decoder->axis, 0, max, 0, 1); + + err = input_register_polled_device(poll_dev); + if (err) { + dev_err(dev, "failed to register polled device\n"); + return err; + } + platform_set_drvdata(pdev, decoder); + + return 0; +} + +static const struct of_device_id gpio_decoder_of_match[] = { + { .compatible = "gpio-decoder", }, + { }, +}; +MODULE_DEVICE_TABLE(of, gpio_decoder_of_match); + +static struct platform_driver gpio_decoder_driver = { + .probe = gpio_decoder_probe, + .driver = { + .name = "gpio-decoder", + .of_match_table = of_match_ptr(gpio_decoder_of_match), + } +}; +module_platform_driver(gpio_decoder_driver); + +MODULE_DESCRIPTION("GPIO decoder input driver"); +MODULE_AUTHOR("Vignesh R <vigneshr@ti.com>"); +MODULE_LICENSE("GPL v2");