| Message ID | 20160824075859.30979-2-vigneshr@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Aug 24, 2016 at 01:28:58PM +0530, 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 > interfacing 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> > --- > > v3: Fix comments by Andrew and Dmitry > Link to v2: https://lkml.org/lkml/2016/8/23/79 > > .../devicetree/bindings/input/gpio-decoder.txt | 23 ++++ > drivers/input/misc/Kconfig | 12 ++ > drivers/input/misc/Makefile | 1 + > drivers/input/misc/gpio_decoder.c | 134 +++++++++++++++++++++ > 4 files changed, 170 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..14a77fb96cf0 > --- /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 (at least 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..7cdb89397d18 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 || COMPILE_TEST > + 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 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..1c2191d4b143 > --- /dev/null > +++ b/drivers/input/misc/gpio_decoder.c > @@ -0,0 +1,134 @@ > +/* > + * 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. > + * > + * A generic driver to read multiple gpio lines and translate the > + * encoded numeric value into an input event. > + */ > + > +#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]); > + if (val >= 0) { > + ret = (ret << 1) | !!val; > + } else { > + dev_err(decoder->dev, "Error reading gpio\n"); > + break; I think if we fail reading any one of gpio lines we should skip reporting the event. > + } > + } > + > + 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); Shouldn't this be max = (1U << decoder->input_gpios->ndescs) - 1; ? > + > + 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; > + input_set_abs_params(poll_dev->input, decoder->axis, 0, max, 0, 1); Why do you need flat == 1? Do you actually use joydev for this device? > + > + 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; > +} > + > +#ifdef CONFIG_OF > +static const struct of_device_id gpio_decoder_of_match[] = { > + { .compatible = "gpio-decoder", }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, gpio_decoder_of_match); > +#endif > + > +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"); > -- > 2.9.2 > No need to resubmit, I can adjust on my side.
On Thursday 25 August 2016 10:26 PM, Dmitry Torokhov wrote: > On Wed, Aug 24, 2016 at 01:28:58PM +0530, 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 >> interfacing 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> >> --- >> >> v3: Fix comments by Andrew and Dmitry >> Link to v2: https://lkml.org/lkml/2016/8/23/79 >> >> .../devicetree/bindings/input/gpio-decoder.txt | 23 ++++ >> drivers/input/misc/Kconfig | 12 ++ >> drivers/input/misc/Makefile | 1 + >> drivers/input/misc/gpio_decoder.c | 134 +++++++++++++++++++++ >> 4 files changed, 170 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..14a77fb96cf0 >> --- /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 (at least 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..7cdb89397d18 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 || COMPILE_TEST >> + 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 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..1c2191d4b143 >> --- /dev/null >> +++ b/drivers/input/misc/gpio_decoder.c >> @@ -0,0 +1,134 @@ >> +/* >> + * 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. >> + * >> + * A generic driver to read multiple gpio lines and translate the >> + * encoded numeric value into an input event. >> + */ >> + >> +#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]); >> + if (val >= 0) { >> + ret = (ret << 1) | !!val; >> + } else { >> + dev_err(decoder->dev, "Error reading gpio\n"); >> + break; > > I think if we fail reading any one of gpio lines we should skip > reporting the event. > Ok. >> + } >> + } >> + >> + 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); > > Shouldn't this be > > max = (1U << decoder->input_gpios->ndescs) - 1; > > ? Oops, you are right. > >> + >> + 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; >> + input_set_abs_params(poll_dev->input, decoder->axis, 0, max, 0, 1); > > Why do you need flat == 1? Do you actually use joydev for this device? > Sorry, I overlooked flat param when I copied this line from rotary-encoder.c. >> + >> + 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; >> +} >> + >> +#ifdef CONFIG_OF >> +static const struct of_device_id gpio_decoder_of_match[] = { >> + { .compatible = "gpio-decoder", }, >> + { }, >> +}; >> +MODULE_DEVICE_TABLE(of, gpio_decoder_of_match); >> +#endif >> + >> +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"); >> -- >> 2.9.2 >> > > No need to resubmit, I can adjust on my side. Thanks a lot!
On Mon, Aug 29, 2016 at 09:50:28AM +0530, Vignesh R wrote: > > > On Thursday 25 August 2016 10:26 PM, Dmitry Torokhov wrote: > > On Wed, Aug 24, 2016 at 01:28:58PM +0530, 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 > >> interfacing 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> > >> --- > >> > >> v3: Fix comments by Andrew and Dmitry > >> Link to v2: https://lkml.org/lkml/2016/8/23/79 > >> > >> .../devicetree/bindings/input/gpio-decoder.txt | 23 ++++ > >> drivers/input/misc/Kconfig | 12 ++ > >> drivers/input/misc/Makefile | 1 + > >> drivers/input/misc/gpio_decoder.c | 134 +++++++++++++++++++++ > >> 4 files changed, 170 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..14a77fb96cf0 > >> --- /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 (at least 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..7cdb89397d18 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 || COMPILE_TEST > >> + 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 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..1c2191d4b143 > >> --- /dev/null > >> +++ b/drivers/input/misc/gpio_decoder.c > >> @@ -0,0 +1,134 @@ > >> +/* > >> + * 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. > >> + * > >> + * A generic driver to read multiple gpio lines and translate the > >> + * encoded numeric value into an input event. > >> + */ > >> + > >> +#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]); > >> + if (val >= 0) { > >> + ret = (ret << 1) | !!val; > >> + } else { > >> + dev_err(decoder->dev, "Error reading gpio\n"); > >> + break; > > > > I think if we fail reading any one of gpio lines we should skip > > reporting the event. > > > > Ok. > > >> + } > >> + } > >> + > >> + 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); > > > > Shouldn't this be > > > > max = (1U << decoder->input_gpios->ndescs) - 1; > > > > ? > > Oops, you are right. > > > > >> + > >> + 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; > >> + input_set_abs_params(poll_dev->input, decoder->axis, 0, max, 0, 1); > > > > Why do you need flat == 1? Do you actually use joydev for this device? > > > > Sorry, I overlooked flat param when I copied this line from > rotary-encoder.c. > > >> + > >> + 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; > >> +} > >> + > >> +#ifdef CONFIG_OF > >> +static const struct of_device_id gpio_decoder_of_match[] = { > >> + { .compatible = "gpio-decoder", }, > >> + { }, > >> +}; > >> +MODULE_DEVICE_TABLE(of, gpio_decoder_of_match); > >> +#endif > >> + > >> +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"); > >> -- > >> 2.9.2 > >> > > > > No need to resubmit, I can adjust on my side. > > Thanks a lot! Applied, thank you. DTS change should go through some other tree though.
* Dmitry Torokhov <dmitry.torokhov@gmail.com> [160829 20:26]: > Applied, thank you. > > DTS change should go through some other tree though. Thanks I'm picking up the dts patch into omap-for-v4.9/dt. Tony -- 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
diff --git a/Documentation/devicetree/bindings/input/gpio-decoder.txt b/Documentation/devicetree/bindings/input/gpio-decoder.txt new file mode 100644 index 000000000000..14a77fb96cf0 --- /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 (at least 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..7cdb89397d18 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 || COMPILE_TEST + 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 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..1c2191d4b143 --- /dev/null +++ b/drivers/input/misc/gpio_decoder.c @@ -0,0 +1,134 @@ +/* + * 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. + * + * A generic driver to read multiple gpio lines and translate the + * encoded numeric value into an input event. + */ + +#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]); + if (val >= 0) { + ret = (ret << 1) | !!val; + } else { + dev_err(decoder->dev, "Error reading gpio\n"); + break; + } + } + + 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; + 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; +} + +#ifdef CONFIG_OF +static const struct of_device_id gpio_decoder_of_match[] = { + { .compatible = "gpio-decoder", }, + { }, +}; +MODULE_DEVICE_TABLE(of, gpio_decoder_of_match); +#endif + +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");