| Message ID | 20201222085633.10194-3-m.szyprowski@samsung.com |
|---|---|
| State | New |
| Headers | show |
| Series | VIM3: add support for checking 'Function' button state | expand |
On 12/22/20 9:56 AM, Marek Szyprowski wrote: > Add a simple Analog to Digital Converter device based button driver. This > driver binds to the 'adc-keys' device tree node. > > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > --- > drivers/button/Kconfig | 8 +++ > drivers/button/Makefile | 1 + > drivers/button/button-adc.c | 121 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 130 insertions(+) > create mode 100644 drivers/button/button-adc.c > > diff --git a/drivers/button/Kconfig b/drivers/button/Kconfig > index 6b3ec7e55d..6db3c5e93a 100644 > --- a/drivers/button/Kconfig > +++ b/drivers/button/Kconfig > @@ -9,6 +9,14 @@ config BUTTON > can provide access to board-specific buttons. Use of the device tree > for configuration is encouraged. > > +config BUTTON_ADC > + bool "Button adc" > + depends on BUTTON > + help > + Enable support for buttons which are connected to Analog to Digital > + Converter device. The ADC driver must use driver model. Buttons are > + configured using the device tree. > + > config BUTTON_GPIO > bool "Button gpio" > depends on BUTTON > diff --git a/drivers/button/Makefile b/drivers/button/Makefile > index fcc10ebe8d..bbd18af149 100644 > --- a/drivers/button/Makefile > +++ b/drivers/button/Makefile > @@ -3,4 +3,5 @@ > # Copyright (C) 2020 Philippe Reynes <philippe.reynes@softathome.com> > > obj-$(CONFIG_BUTTON) += button-uclass.o > +obj-$(CONFIG_BUTTON_ADC) += button-adc.o > obj-$(CONFIG_BUTTON_GPIO) += button-gpio.o > diff --git a/drivers/button/button-adc.c b/drivers/button/button-adc.c > new file mode 100644 > index 0000000000..bf99dd8b43 > --- /dev/null > +++ b/drivers/button/button-adc.c > @@ -0,0 +1,121 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2020 Samsung Electronics Co., Ltd. > + * http://www.samsung.com > + * Author: Marek Szyprowski <m.szyprowski@samsung.com> > + */ > + > +#include <common.h> > +#include <adc.h> > +#include <button.h> > +#include <dm.h> > +#include <dm/lists.h> > +#include <dm/uclass-internal.h> > + > +/** > + * struct button_adc_priv - private data for button-adc driver. > + * > + * @adc: Analog to Digital Converter device to which button is connected. > + * @channel: channel of the ADC device to probe the button state. > + */ > +struct button_adc_priv { > + struct udevice *adc; > + int channel; > +}; > + > +static enum button_state_t button_adc_get_state(struct udevice *dev) > +{ > + struct button_adc_priv *priv = dev_get_priv(dev); > + unsigned int val, mask; > + int ret; > + > + ret = adc_start_channel(priv->adc, priv->channel); > + if (ret) > + return ret; > + > + ret = adc_channel_data(priv->adc, priv->channel, &val); > + if (ret) > + return ret; > + > + ret = adc_data_mask(priv->adc, &mask); > + if (ret) > + return ret; > + > + /* getting state is simplified a bit */ > + if (ret == 0) > + return (val < mask / 2) ? BUTTON_ON : BUTTON_OFF; > + > + return ret; > +} > + > +static int button_adc_probe(struct udevice *dev) > +{ > + struct button_uc_plat *uc_plat = dev_get_uclass_platdata(dev); > + struct button_adc_priv *priv = dev_get_priv(dev); > + struct ofnode_phandle_args args; > + int ret; > + > + /* Ignore the top-level button node */ > + if (!uc_plat->label) > + return 0; > + > + ret = dev_read_phandle_with_args(dev->parent, "io-channels", > + "#io-channel-cells", 0, 0, &args); > + if (ret) > + return ret; > + > + ret = uclass_get_device_by_ofnode(UCLASS_ADC, args.node, &priv->adc); > + if (ret) > + return ret; > + > + priv->channel = args.args[0]; > + > + return ret; > +} > + > +static int button_adc_bind(struct udevice *parent) > +{ > + struct udevice *dev; > + ofnode node; > + int ret; > + > + dev_for_each_subnode(node, parent) { > + struct button_uc_plat *uc_plat; > + const char *label; > + > + label = ofnode_read_string(node, "label"); > + if (!label) { > + debug("%s: node %s has no label\n", __func__, > + ofnode_get_name(node)); > + return -EINVAL; > + } > + ret = device_bind_driver_to_node(parent, "button_adc", > + ofnode_get_name(node), > + node, &dev); This code does not match the binding. The binding defines a voltage ladder where you have multiple voltage ranges and multiple buttons. You need to consider the threshold voltages. Have a look at Linux' drivers/input/keyboard/adc-keys.c. Beware that code is also incorrect as the author ignores the meaning of "threshold" and uses it it as closest voltage. Best regards Heinrich > + if (ret) > + return ret; > + uc_plat = dev_get_uclass_platdata(dev); > + uc_plat->label = label; > + } > + > + return 0; > +} > + > +static const struct button_ops button_adc_ops = { > + .get_state = button_adc_get_state, > +}; > + > +static const struct udevice_id button_adc_ids[] = { > + { .compatible = "adc-keys" }, > + { } > +}; > + > +U_BOOT_DRIVER(button_adc) = { > + .name = "button_adc", > + .id = UCLASS_BUTTON, > + .of_match = button_adc_ids, > + .ops = &button_adc_ops, > + .priv_auto_alloc_size = sizeof(struct button_adc_priv), > + .bind = button_adc_bind, > + .probe = button_adc_probe, > +}; >
Hi, On Tue, 22 Dec 2020 at 02:46, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote: > > On 12/22/20 9:56 AM, Marek Szyprowski wrote: > > Add a simple Analog to Digital Converter device based button driver. This > > driver binds to the 'adc-keys' device tree node. > > > > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > > --- > > drivers/button/Kconfig | 8 +++ > > drivers/button/Makefile | 1 + > > drivers/button/button-adc.c | 121 ++++++++++++++++++++++++++++++++++++ > > 3 files changed, 130 insertions(+) > > create mode 100644 drivers/button/button-adc.c > > > > diff --git a/drivers/button/Kconfig b/drivers/button/Kconfig > > index 6b3ec7e55d..6db3c5e93a 100644 > > --- a/drivers/button/Kconfig > > +++ b/drivers/button/Kconfig > > @@ -9,6 +9,14 @@ config BUTTON > > can provide access to board-specific buttons. Use of the device tree > > for configuration is encouraged. > > > > +config BUTTON_ADC > > + bool "Button adc" > > + depends on BUTTON > > + help > > + Enable support for buttons which are connected to Analog to Digital > > + Converter device. The ADC driver must use driver model. Buttons are > > + configured using the device tree. > > + > > config BUTTON_GPIO > > bool "Button gpio" > > depends on BUTTON > > diff --git a/drivers/button/Makefile b/drivers/button/Makefile > > index fcc10ebe8d..bbd18af149 100644 > > --- a/drivers/button/Makefile > > +++ b/drivers/button/Makefile > > @@ -3,4 +3,5 @@ > > # Copyright (C) 2020 Philippe Reynes <philippe.reynes@softathome.com> > > > > obj-$(CONFIG_BUTTON) += button-uclass.o > > +obj-$(CONFIG_BUTTON_ADC) += button-adc.o > > obj-$(CONFIG_BUTTON_GPIO) += button-gpio.o > > diff --git a/drivers/button/button-adc.c b/drivers/button/button-adc.c > > new file mode 100644 > > index 0000000000..bf99dd8b43 > > --- /dev/null > > +++ b/drivers/button/button-adc.c > > @@ -0,0 +1,121 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Copyright (C) 2020 Samsung Electronics Co., Ltd. > > + * http://www.samsung.com > > + * Author: Marek Szyprowski <m.szyprowski@samsung.com> > > + */ > > + > > +#include <common.h> > > +#include <adc.h> > > +#include <button.h> > > +#include <dm.h> > > +#include <dm/lists.h> > > +#include <dm/uclass-internal.h> > > + > > +/** > > + * struct button_adc_priv - private data for button-adc driver. > > + * > > + * @adc: Analog to Digital Converter device to which button is connected. > > + * @channel: channel of the ADC device to probe the button state. > > + */ > > +struct button_adc_priv { > > + struct udevice *adc; > > + int channel; > > +}; > > + > > +static enum button_state_t button_adc_get_state(struct udevice *dev) > > +{ > > + struct button_adc_priv *priv = dev_get_priv(dev); > > + unsigned int val, mask; > > + int ret; > > + > > + ret = adc_start_channel(priv->adc, priv->channel); > > + if (ret) > > + return ret; > > + > > + ret = adc_channel_data(priv->adc, priv->channel, &val); > > + if (ret) > > + return ret; > > + > > + ret = adc_data_mask(priv->adc, &mask); > > + if (ret) > > + return ret; > > + > > + /* getting state is simplified a bit */ > > + if (ret == 0) > > + return (val < mask / 2) ? BUTTON_ON : BUTTON_OFF; > > + > > + return ret; > > +} > > + > > +static int button_adc_probe(struct udevice *dev) > > +{ > > + struct button_uc_plat *uc_plat = dev_get_uclass_platdata(dev); > > + struct button_adc_priv *priv = dev_get_priv(dev); > > + struct ofnode_phandle_args args; > > + int ret; > > + > > + /* Ignore the top-level button node */ > > + if (!uc_plat->label) > > + return 0; > > + > > + ret = dev_read_phandle_with_args(dev->parent, "io-channels", > > + "#io-channel-cells", 0, 0, &args); > > + if (ret) > > + return ret; > > + > > + ret = uclass_get_device_by_ofnode(UCLASS_ADC, args.node, &priv->adc); > > + if (ret) > > + return ret; > > + > > + priv->channel = args.args[0]; > > + > > + return ret; > > +} > > + > > +static int button_adc_bind(struct udevice *parent) > > +{ > > + struct udevice *dev; > > + ofnode node; > > + int ret; > > + > > + dev_for_each_subnode(node, parent) { > > + struct button_uc_plat *uc_plat; > > + const char *label; > > + > > + label = ofnode_read_string(node, "label"); > > + if (!label) { > > + debug("%s: node %s has no label\n", __func__, > > + ofnode_get_name(node)); > > + return -EINVAL; > > + } > > + ret = device_bind_driver_to_node(parent, "button_adc", > > + ofnode_get_name(node), > > + node, &dev); > > This code does not match the binding. The binding defines a voltage > ladder where you have multiple voltage ranges and multiple buttons. > > You need to consider the threshold voltages. > > Have a look at Linux' drivers/input/keyboard/adc-keys.c. Beware that > code is also incorrect as the author ignores the meaning of "threshold" > and uses it it as closest voltage. Apart from that, from a DM point of view, this looks good. Regards, Simon
diff --git a/drivers/button/Kconfig b/drivers/button/Kconfig index 6b3ec7e55d..6db3c5e93a 100644 --- a/drivers/button/Kconfig +++ b/drivers/button/Kconfig @@ -9,6 +9,14 @@ config BUTTON can provide access to board-specific buttons. Use of the device tree for configuration is encouraged. +config BUTTON_ADC + bool "Button adc" + depends on BUTTON + help + Enable support for buttons which are connected to Analog to Digital + Converter device. The ADC driver must use driver model. Buttons are + configured using the device tree. + config BUTTON_GPIO bool "Button gpio" depends on BUTTON diff --git a/drivers/button/Makefile b/drivers/button/Makefile index fcc10ebe8d..bbd18af149 100644 --- a/drivers/button/Makefile +++ b/drivers/button/Makefile @@ -3,4 +3,5 @@ # Copyright (C) 2020 Philippe Reynes <philippe.reynes@softathome.com> obj-$(CONFIG_BUTTON) += button-uclass.o +obj-$(CONFIG_BUTTON_ADC) += button-adc.o obj-$(CONFIG_BUTTON_GPIO) += button-gpio.o diff --git a/drivers/button/button-adc.c b/drivers/button/button-adc.c new file mode 100644 index 0000000000..bf99dd8b43 --- /dev/null +++ b/drivers/button/button-adc.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * Author: Marek Szyprowski <m.szyprowski@samsung.com> + */ + +#include <common.h> +#include <adc.h> +#include <button.h> +#include <dm.h> +#include <dm/lists.h> +#include <dm/uclass-internal.h> + +/** + * struct button_adc_priv - private data for button-adc driver. + * + * @adc: Analog to Digital Converter device to which button is connected. + * @channel: channel of the ADC device to probe the button state. + */ +struct button_adc_priv { + struct udevice *adc; + int channel; +}; + +static enum button_state_t button_adc_get_state(struct udevice *dev) +{ + struct button_adc_priv *priv = dev_get_priv(dev); + unsigned int val, mask; + int ret; + + ret = adc_start_channel(priv->adc, priv->channel); + if (ret) + return ret; + + ret = adc_channel_data(priv->adc, priv->channel, &val); + if (ret) + return ret; + + ret = adc_data_mask(priv->adc, &mask); + if (ret) + return ret; + + /* getting state is simplified a bit */ + if (ret == 0) + return (val < mask / 2) ? BUTTON_ON : BUTTON_OFF; + + return ret; +} + +static int button_adc_probe(struct udevice *dev) +{ + struct button_uc_plat *uc_plat = dev_get_uclass_platdata(dev); + struct button_adc_priv *priv = dev_get_priv(dev); + struct ofnode_phandle_args args; + int ret; + + /* Ignore the top-level button node */ + if (!uc_plat->label) + return 0; + + ret = dev_read_phandle_with_args(dev->parent, "io-channels", + "#io-channel-cells", 0, 0, &args); + if (ret) + return ret; + + ret = uclass_get_device_by_ofnode(UCLASS_ADC, args.node, &priv->adc); + if (ret) + return ret; + + priv->channel = args.args[0]; + + return ret; +} + +static int button_adc_bind(struct udevice *parent) +{ + struct udevice *dev; + ofnode node; + int ret; + + dev_for_each_subnode(node, parent) { + struct button_uc_plat *uc_plat; + const char *label; + + label = ofnode_read_string(node, "label"); + if (!label) { + debug("%s: node %s has no label\n", __func__, + ofnode_get_name(node)); + return -EINVAL; + } + ret = device_bind_driver_to_node(parent, "button_adc", + ofnode_get_name(node), + node, &dev); + if (ret) + return ret; + uc_plat = dev_get_uclass_platdata(dev); + uc_plat->label = label; + } + + return 0; +} + +static const struct button_ops button_adc_ops = { + .get_state = button_adc_get_state, +}; + +static const struct udevice_id button_adc_ids[] = { + { .compatible = "adc-keys" }, + { } +}; + +U_BOOT_DRIVER(button_adc) = { + .name = "button_adc", + .id = UCLASS_BUTTON, + .of_match = button_adc_ids, + .ops = &button_adc_ops, + .priv_auto_alloc_size = sizeof(struct button_adc_priv), + .bind = button_adc_bind, + .probe = button_adc_probe, +};
Add a simple Analog to Digital Converter device based button driver. This driver binds to the 'adc-keys' device tree node. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- drivers/button/Kconfig | 8 +++ drivers/button/Makefile | 1 + drivers/button/button-adc.c | 121 ++++++++++++++++++++++++++++++++++++ 3 files changed, 130 insertions(+) create mode 100644 drivers/button/button-adc.c -- 2.17.1