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 | 146 ++++++++++++++++++++++++++++++++++++ 3 files changed, 155 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..eed86564fb --- /dev/null +++ b/drivers/button/button-adc.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2021 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 <log.h> +#include <dm.h> +#include <dm/lists.h> +#include <dm/of_access.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. + * @min: minimal uV value to consider button as pressed. + * @max: maximal uV value to consider button as pressed. + */ +struct button_adc_priv { + struct udevice *adc; + int channel; + int min; + int max; +}; + +static enum button_state_t button_adc_get_state(struct udevice *dev) +{ + struct button_adc_priv *priv = dev_get_priv(dev); + unsigned int val; + int ret, uV; + + 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_raw_to_uV(priv->adc, val, &uV); + if (ret) + return ret; + + return (uV >= priv->min && uV < priv->max) ? BUTTON_ON : BUTTON_OFF; +} + +static int button_adc_of_to_plat(struct udevice *dev) +{ + struct button_uc_plat *uc_plat = dev_get_uclass_plat(dev); + struct button_adc_priv *priv = dev_get_priv(dev); + struct ofnode_phandle_args args; + u32 treshold, up_treshold, t; + ofnode node; + 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; + + ret = ofnode_read_u32(dev_ofnode(dev->parent), + "keyup-threshold-microvolt", &up_treshold); + if (ret) + return ret; + + ret = ofnode_read_u32(dev_ofnode(dev), "press-threshold-microvolt", + &treshold); + if (ret) + return ret; + + dev_for_each_subnode(node, dev->parent) { + ret = ofnode_read_u32(node, "press-threshold-microvolt", &t); + if (ret) + return ret; + + if (t > treshold) + up_treshold = t; + } + + priv->channel = args.args[0]; + priv->min = treshold; + priv->max = up_treshold; + + 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_plat(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 = sizeof(struct button_adc_priv), + .bind = button_adc_bind, + .of_to_plat = button_adc_of_to_plat, +};

Add support for getting the 'vref-supply' regulator and register it as ADC's reference voltage regulator, so clients can translate sampled ADC values to the voltage.

Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Simon Glass sjg@chromium.org --- drivers/adc/meson-saradc.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)

diff --git a/drivers/adc/meson-saradc.c b/drivers/adc/meson-saradc.c index 21db55831d..1a45a3a265 100644 --- a/drivers/adc/meson-saradc.c +++ b/drivers/adc/meson-saradc.c @@ -18,6 +18,7 @@ #include <linux/delay.h> #include <linux/math64.h> #include <linux/bitfield.h> +#include <power/regulator.h>

#define MESON_SAR_ADC_REG0 0x00 #define MESON_SAR_ADC_REG0_PANEL_DETECT BIT(31) @@ -656,7 +657,10 @@ static int meson_saradc_stop(struct udevice *dev)

static int meson_saradc_probe(struct udevice *dev) { + struct adc_uclass_plat *uc_pdata = dev_get_uclass_plat(dev); struct meson_saradc_priv *priv = dev_get_priv(dev); + struct udevice *vref; + int vref_uv; int ret;

ret = regmap_init_mem(dev_ofnode(dev), &priv->regmap); @@ -675,6 +679,23 @@ static int meson_saradc_probe(struct udevice *dev)

priv->active_channel = -1;

+ ret = device_get_supply_regulator(dev, "vref-supply", &vref); + if (ret) { + printf("can't get vref-supply: %d\n", ret); + return ret; + } + + vref_uv = regulator_get_value(vref); + if (vref_uv < 0) { + printf("can't get vref-supply value: %d\n", vref_uv); + return vref_uv; + } + + /* VDD supplied by common vref pin */ + uc_pdata->vdd_supply = vref; + uc_pdata->vdd_microvolts = vref_uv; + uc_pdata->vss_microvolts = 0; + return 0; }

Add adc-keys device to the sandbox/test.dts and connect it to the channel #3 of the sandbox_adc driver. The default values sampled by sandbox_adc driver determines that button3 and button4 are released and button5 is pressed.

Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- arch/sandbox/dts/test.dts | 24 ++++++++++++++++++- configs/sandbox_defconfig | 1 + test/dm/button.c | 50 +++++++++++++++++++++++++++++++++++++-- 3 files changed, 72 insertions(+), 3 deletions(-)

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts index e95f4631bf..a32b019ae7 100644 --- a/arch/sandbox/dts/test.dts +++ b/arch/sandbox/dts/test.dts @@ -69,6 +69,27 @@ }; };

+ buttons2 { + compatible = "adc-keys"; + io-channels = <&adc 3>; + keyup-threshold-microvolt = <3000000>; + + button-up { + label = "button3"; + press-threshold-microvolt = <1500000>; + }; + + button-down { + label = "button4"; + press-threshold-microvolt = <1000000>; + }; + + button-enter { + label = "button5"; + press-threshold-microvolt = <500000>; + }; + }; + cros_ec: cros-ec { reg = <0 0>; compatible = "google,cros-ec-sandbox"; @@ -587,8 +608,9 @@ i2c-eeprom = <&bootcount_i2c>; };

- adc@0 { + adc: adc@0 { compatible = "sandbox,adc"; + #io-channel-cells = <1>; vdd-supply = <&buck2>; vss-microvolts = <0>; }; diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig index 0c7674efc9..3731bf05ff 100644 --- a/configs/sandbox_defconfig +++ b/configs/sandbox_defconfig @@ -122,6 +122,7 @@ CONFIG_DM_BOOTCOUNT=y CONFIG_DM_BOOTCOUNT_RTC=y CONFIG_DM_BOOTCOUNT_I2C_EEPROM=y CONFIG_BUTTON=y +CONFIG_BUTTON_ADC=y CONFIG_BUTTON_GPIO=y CONFIG_CLK=y CONFIG_CLK_COMPOSITE_CCF=y diff --git a/test/dm/button.c b/test/dm/button.c index ecaa47cf5f..f8a7fab61d 100644 --- a/test/dm/button.c +++ b/test/dm/button.c @@ -7,7 +7,10 @@

#include <common.h> #include <dm.h> +#include <adc.h> #include <button.h> +#include <power/regulator.h> +#include <power/sandbox_pmic.h> #include <asm/gpio.h> #include <dm/test.h> #include <test/ut.h> @@ -17,11 +20,20 @@ static int dm_test_button_base(struct unit_test_state *uts) { struct udevice *dev;

- /* Get the top-level device */ + /* Get the top-level gpio buttons device */ ut_assertok(uclass_get_device(UCLASS_BUTTON, 0, &dev)); + /* Get the 2 gpio buttons */ ut_assertok(uclass_get_device(UCLASS_BUTTON, 1, &dev)); ut_assertok(uclass_get_device(UCLASS_BUTTON, 2, &dev)); - ut_asserteq(-ENODEV, uclass_get_device(UCLASS_BUTTON, 3, &dev)); + + /* Get the top-level adc buttons device */ + ut_assertok(uclass_get_device(UCLASS_BUTTON, 3, &dev)); + /* Get the 3 adc buttons */ + ut_assertok(uclass_get_device(UCLASS_BUTTON, 4, &dev)); + ut_assertok(uclass_get_device(UCLASS_BUTTON, 5, &dev)); + ut_assertok(uclass_get_device(UCLASS_BUTTON, 6, &dev)); + + ut_asserteq(-ENODEV, uclass_get_device(UCLASS_BUTTON, 7, &dev));

return 0; } @@ -72,3 +84,37 @@ static int dm_test_button_label(struct unit_test_state *uts) return 0; } DM_TEST(dm_test_button_label, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT); + +/* Test adc-keys driver */ +static int dm_test_button_keys_adc(struct unit_test_state *uts) +{ + struct udevice *supply; + struct udevice *dev; + int uV; + + ut_assertok(uclass_get_device_by_name(UCLASS_ADC, "adc@0", &dev)); + + ut_assertok(regulator_get_by_devname(SANDBOX_BUCK2_DEVNAME, &supply)); + ut_assertok(regulator_set_value(supply, SANDBOX_BUCK2_SET_UV)); + ut_asserteq(SANDBOX_BUCK2_SET_UV, regulator_get_value(supply)); + /* Update ADC plat and get new Vdd value */ + ut_assertok(adc_vdd_value(dev, &uV)); + ut_asserteq(SANDBOX_BUCK2_SET_UV, uV); + + /* + * sandbox-adc returns constant value on channel 3, is used by adc-keys: + * SANDBOX_ADC_CHANNEL3_DATA * SANDBOX_BUCK2_SET_UV / SANDBOX_ADC_DATA_MASK = + * 0x3000 * 3300000 / 0xffff = 618759uV + * This means that button3 and button4 are released and button5 + * is pressed. + */ + ut_assertok(button_get_by_label("button3", &dev)); + ut_asserteq(BUTTON_OFF, button_get_state(dev)); + ut_assertok(button_get_by_label("button4", &dev)); + ut_asserteq(BUTTON_OFF, button_get_state(dev)); + ut_assertok(button_get_by_label("button5", &dev)); + ut_asserteq(BUTTON_ON, button_get_state(dev)); + + return 0; +} +DM_TEST(dm_test_button_keys_adc, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);