From 2c1fab89e83245a520871e807e233e66cbdb7c57 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 1 Jan 2014 19:44:49 +0100 Subject: [PATCH] input: Add new sun4i-lradc-keys driver Allwinnner sunxi SoCs have a low resolution adc (called lradc) which is specifically designed to have various (tablet) keys (ie home, back, search, etc). attached to it using a resistor network. This adds a driver for this. There are 2 channels, currently this driver only supports chan0 since there are no boards known to use chan1. This has been tested on an olimex a10s-olinuxino-micro, a13-olinuxino, and a20-olinuxino-micro. Signed-off-by: Hans de Goede -- Changes in v2: -Change devicetree bindings to use a per key subnode, like gpio-keys does --- .../devicetree/bindings/input/sun4i-lradc-keys.txt | 62 +++++ MAINTAINERS | 7 + drivers/input/keyboard/Kconfig | 10 + drivers/input/keyboard/Makefile | 1 + drivers/input/keyboard/sun4i-lradc-keys.c | 258 +++++++++++++++++++++ 5 files changed, 338 insertions(+) create mode 100644 Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt create mode 100644 drivers/input/keyboard/sun4i-lradc-keys.c --- /dev/null +++ b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt @@ -0,0 +1,62 @@ +Allwinner sun4i low res adc attached tablet keys +------------------------------------------------ + +Required properties: + - compatible: "allwinner,sun4i-a10-lradc-keys" + - reg: mmio address range of the chip + - interrupts: interrupt to which the chip is connected + - vref-supply: powersupply for the lradc reference voltage + +Each key is represented as a sub-node of "allwinner,sun4i-a10-lradc-keys": + +Required subnode-properties: + - label: Descriptive name of the key. + - linux,code: Keycode to emit. + - channel: Channel this key is attached to, mut be 0 or 1. + - voltage: Voltage in µV at lradc input when this key is pressed. + +Example: + +#include + + lradc: lradc@01c22800 { + compatible = "allwinner,sun4i-a10-lradc-keys"; + reg = <0x01c22800 0x100>; + interrupts = <31>; + vref-supply = <®_vcc3v0>; + + button@191 { + label = "Volume Up"; + linux,code = ; + channel = <0>; + voltage = <191274>; + }; + + button@392 { + label = "Volume Down"; + linux,code = ; + channel = <0>; + voltage = <392644>; + }; + + button@601 { + label = "Menu"; + linux,code = ; + channel = <0>; + voltage = <601151>; + }; + + button@795 { + label = "Enter"; + linux,code = ; + channel = <0>; + voltage = <795090>; + }; + + button@987 { + label = "Home"; + linux,code = ; + channel = <0>; + voltage = <987387>; + }; + }; --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9015,6 +9015,13 @@ F: arch/m68k/sun3*/ F: arch/m68k/include/asm/sun3* F: drivers/net/ethernet/i825xx/sun3* +SUN4I LOW RES ADC ATTACHED TABLET KEYS DRIVER +M: Hans de Goede +L: linux-input@vger.kernel.org +S: Maintained +F: Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt +F: drivers/input/keyboard/sun4i-lradc-keys.c + SUNDANCE NETWORK DRIVER M: Denis Kirjanov L: netdev@vger.kernel.org --- a/drivers/input/keyboard/Kconfig +++ b/drivers/input/keyboard/Kconfig @@ -567,6 +567,16 @@ config KEYBOARD_STMPE To compile this driver as a module, choose M here: the module will be called stmpe-keypad. +config KEYBOARD_SUN4I_LRADC + tristate "Allwinner sun4i low res adc attached tablet keys support" + depends on ARCH_SUNXI + help + This selects support for the Allwinner low res adc attached tablet + keys found on Allwinner sunxi SoCs. + + To compile this driver as a module, choose M here: the + module will be called sun4i-lradc-keys. + config KEYBOARD_DAVINCI tristate "TI DaVinci Key Scan" depends on ARCH_DAVINCI_DM365 --- a/drivers/input/keyboard/Makefile +++ b/drivers/input/keyboard/Makefile @@ -53,6 +53,7 @@ obj-$(CONFIG_KEYBOARD_SPEAR) += spear-k obj-$(CONFIG_KEYBOARD_STMPE) += stmpe-keypad.o obj-$(CONFIG_KEYBOARD_STOWAWAY) += stowaway.o obj-$(CONFIG_KEYBOARD_ST_KEYSCAN) += st-keyscan.o +obj-$(CONFIG_KEYBOARD_SUN4I_LRADC) += sun4i-lradc-keys.o obj-$(CONFIG_KEYBOARD_SUNKBD) += sunkbd.o obj-$(CONFIG_KEYBOARD_TC3589X) += tc3589x-keypad.o obj-$(CONFIG_KEYBOARD_TEGRA) += tegra-kbc.o --- /dev/null +++ b/drivers/input/keyboard/sun4i-lradc-keys.c @@ -0,0 +1,258 @@ +/* + * Allwinner sun4i low res adc attached tablet keys driver + * + * Copyright (C) 2014 Hans de Goede + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +/* + * Allwinnner sunxi SoCs have a lradc which is specifically designed to have + * various (tablet) keys (ie home, back, search, etc). attached to it using + * a resistor network. This driver is for the keys on such boards. + * + * There are 2 channels, currently this driver only supports channel 0 since + * there are no boards known to use channel 1. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define LRADC_CTRL 0x00 +#define LRADC_INTC 0x04 +#define LRADC_INTS 0x08 +#define LRADC_DATA0 0x0c +#define LRADC_DATA1 0x10 + +/* LRADC_CTRL bits */ +#define FIRST_CONVERT_DLY(x) ((x) << 24) /* 8 bits */ +#define CHAN_SELECT(x) ((x) << 22) /* 2 bits */ +#define CONTINUE_TIME_SEL(x) ((x) << 16) /* 4 bits */ +#define KEY_MODE_SEL(x) ((x) << 12) /* 2 bits */ +#define LEVELA_B_CNT(x) ((x) << 8) /* 4 bits */ +#define HOLD_EN(x) ((x) << 6) +#define LEVELB_VOL(x) ((x) << 4) /* 2 bits */ +#define SAMPLE_RATE(x) ((x) << 2) /* 2 bits */ +#define ENABLE(x) ((x) << 0) + +/* LRADC_INTC and LRADC_INTS bits */ +#define CHAN1_KEYUP_IRQ BIT(12) +#define CHAN1_ALRDY_HOLD_IRQ BIT(11) +#define CHAN1_HOLD_IRQ BIT(10) +#define CHAN1_KEYDOWN_IRQ BIT(9) +#define CHAN1_DATA_IRQ BIT(8) +#define CHAN0_KEYUP_IRQ BIT(4) +#define CHAN0_ALRDY_HOLD_IRQ BIT(3) +#define CHAN0_HOLD_IRQ BIT(2) +#define CHAN0_KEYDOWN_IRQ BIT(1) +#define CHAN0_DATA_IRQ BIT(0) + +struct sun4i_lradc_keymap { + u32 voltage; + u32 keycode; +}; + +struct sun4i_lradc_data { + struct device *dev; + struct input_dev *input; + void __iomem *base; + struct regulator *vref_supply; + struct sun4i_lradc_keymap *chan0_map; + u32 chan0_map_count; + u32 chan0_keycode; + u32 vref; +}; + +static irqreturn_t sun4i_lradc_irq(int irq, void *dev_id) +{ + struct sun4i_lradc_data *lradc = dev_id; + u32 i, ints, val, voltage, diff, keycode = 0, closest = 0xffffffff; + + ints = readl(lradc->base + LRADC_INTS); + + /* + * lradc supports only one keypress at a time, release does not give + * any info as to which key was released, so we cache the keycode. + */ + if ((ints & CHAN0_KEYDOWN_IRQ) && lradc->chan0_keycode == 0) { + val = readl(lradc->base + LRADC_DATA0) & 0x3f; + voltage = val * lradc->vref / 63; + + for (i = 0; i < lradc->chan0_map_count; i++) { + diff = abs(lradc->chan0_map[i].voltage - voltage); + if (diff < closest) { + closest = diff; + keycode = lradc->chan0_map[i].keycode; + } + } + + lradc->chan0_keycode = keycode; + input_report_key(lradc->input, lradc->chan0_keycode, 1); + } + + if (ints & CHAN0_KEYUP_IRQ) { + input_report_key(lradc->input, lradc->chan0_keycode, 0); + lradc->chan0_keycode = 0; + } + + input_sync(lradc->input); + + writel(ints, lradc->base + LRADC_INTS); + + return IRQ_HANDLED; +} + +static int sun4i_lradc_open(struct input_dev *dev) +{ + struct sun4i_lradc_data *lradc = input_get_drvdata(dev); + int ret; + + ret = regulator_enable(lradc->vref_supply); + if (ret) + return ret; + + /* lradc Vref internally is divided by 2/3 */ + lradc->vref = regulator_get_voltage(lradc->vref_supply) * 2 / 3; + + /* + * Set sample time to 4 ms / 250 Hz. Wait 2 * 4 ms for key to + * stabilize on press, wait (1 + 1) * 4 ms for key release + */ + writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) | + SAMPLE_RATE(0) | ENABLE(1), lradc->base + LRADC_CTRL); + + writel(CHAN0_KEYUP_IRQ | CHAN0_KEYDOWN_IRQ, lradc->base + LRADC_INTC); + + return 0; +} + +static void sun4i_lradc_close(struct input_dev *dev) +{ + struct sun4i_lradc_data *lradc = input_get_drvdata(dev); + + /* Disable lradc, leave other settings unchanged */ + writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) | + SAMPLE_RATE(2), lradc->base + LRADC_CTRL); + writel(0, lradc->base + LRADC_INTC); + + regulator_disable(lradc->vref_supply); +} + +static int sun4i_lradc_probe(struct platform_device *pdev) +{ + struct sun4i_lradc_data *lradc; + struct device *dev = &pdev->dev; + struct device_node *pp, *np = dev->of_node; + u32 channel; + int i, ret; + + lradc = devm_kzalloc(dev, sizeof(struct sun4i_lradc_data), GFP_KERNEL); + if (!lradc) + return -ENOMEM; + + lradc->chan0_map_count = of_get_child_count(np); + lradc->chan0_map = devm_kmalloc(dev, lradc->chan0_map_count * + sizeof(struct sun4i_lradc_keymap), GFP_KERNEL); + if (!lradc->chan0_map) + return -ENOMEM; + + i = 0; + for_each_child_of_node(np, pp) { + struct sun4i_lradc_keymap *map = &lradc->chan0_map[i]; + + ret = of_property_read_u32(pp, "channel", &channel); + if (ret || channel != 0) { + dev_err(dev, "%s: Inval channel prop\n", pp->name); + return -EINVAL; + } + + ret = of_property_read_u32(pp, "voltage", &map->voltage); + if (ret) { + dev_err(dev, "%s: Inval voltage prop\n", pp->name); + return -EINVAL; + } + + ret = of_property_read_u32(pp, "linux,code", &map->keycode); + if (ret) { + dev_err(dev, "%s: Inval linux,code prop\n", pp->name); + return -EINVAL; + } + + i++; + } + + lradc->vref_supply = devm_regulator_get(dev, "vref"); + if (IS_ERR(lradc->vref_supply)) + return PTR_ERR(lradc->vref_supply); + + lradc->dev = dev; + lradc->input = devm_input_allocate_device(dev); + if (!lradc->input) + return -ENOMEM; + + lradc->input->name = pdev->name; + lradc->input->phys = "sun4i_lradc/input0"; + lradc->input->open = sun4i_lradc_open; + lradc->input->close = sun4i_lradc_close; + lradc->input->id.bustype = BUS_HOST; + lradc->input->id.vendor = 0x0001; + lradc->input->id.product = 0x0001; + lradc->input->id.version = 0x0100; + lradc->input->evbit[0] = BIT(EV_SYN) | BIT(EV_KEY); + for (i = 0; i < lradc->chan0_map_count; i++) + set_bit(lradc->chan0_map[i].keycode, lradc->input->keybit); + input_set_drvdata(lradc->input, lradc); + + lradc->base = devm_ioremap_resource(dev, + platform_get_resource(pdev, IORESOURCE_MEM, 0)); + if (IS_ERR(lradc->base)) + return PTR_ERR(lradc->base); + + ret = devm_request_irq(dev, platform_get_irq(pdev, 0), sun4i_lradc_irq, + 0, "sun4i-a10-lradc-keys", lradc); + if (ret) + return ret; + + ret = input_register_device(lradc->input); + if (ret) + return ret; + + platform_set_drvdata(pdev, lradc); + return 0; +} + +static const struct of_device_id sun4i_lradc_of_match[] = { + { .compatible = "allwinner,sun4i-a10-lradc-keys", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, sun4i_lradc_of_match); + +static struct platform_driver sun4i_lradc_driver = { + .driver = { + .name = "sun4i-a10-lradc-keys", + .of_match_table = of_match_ptr(sun4i_lradc_of_match), + }, + .probe = sun4i_lradc_probe, +}; + +module_platform_driver(sun4i_lradc_driver); + +MODULE_DESCRIPTION("Allwinner sun4i low res adc attached tablet keys driver"); +MODULE_AUTHOR("Hans de Goede "); +MODULE_LICENSE("GPL");