Re: [PATCH v2 1/4] input: Add new sun4i-lradc-keys driver

Hans de Goede
2014-10-22T10:45:22Z

Hi,

On 10/21/2014 07:04 PM, Maxime Ripard wrote:
> Hi Hans,
>
> Thanks, a lot for respinning this.
>
> On Tue, Oct 21, 2014 at 10:24:47AM +0200, Hans de Goede wrote:
>> 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 <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> --
>> Changes in v2:
>> -Change devicetree bindings to use a per key subnode, like gpio-keys does
>> ---
>> .../devicetree/bindings/input/sun4i-lradc-keys.txt | 57 +++++
>> MAINTAINERS | 7 +
>> drivers/input/keyboard/Kconfig | 10 +
>> drivers/input/keyboard/Makefile | 1 +
>> drivers/input/keyboard/sun4i-lradc-keys.c | 259 +++++++++++++++++++++
>> 5 files changed, 334 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
>> create mode 100644 drivers/input/keyboard/sun4i-lradc-keys.c
>>
>> diff --git a/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
>> new file mode 100644
>> index 0000000..36a141b
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
>> @@ -0,0 +1,57 @@
>> +Allwinner sun4i low res adc attached tablet keys
>> +------------------------------------------------
>> +
>> +Required properties:
>> + - compatible: "allwinner,sun4i-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-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 <dt-bindings/input/input.h>
>> +
>> + lradc: lradc@01c22800 {
>> + compatible = "allwinner,sun4i-lradc-keys";
>
> You're still using the old pattern for the compatible here, it should
> be allwinner,sun4i-a10-lradc-keys.

Will fix for the next version.

>
>> + reg = <0x01c22800 0x100>;
>> + interrupts = <31>;
>> + vref-supply = <&reg_vcc3v0>;
>> + button@19 {
>
> I guess the node address in centivolts aren't really that common,
> maybe in mV instead?

Ack for using mV, will fix for the next version.

>
>> + label = "Volume Up";
>> + linux,code = <KEY_VOLUMEUP>;
>> + channel = <0>;
>> + voltage = <191274>;
>> + };
>
> And a newline between the nodes please.

Will fix for the next version.

>> + button@39 {
>> + label = "Volume Down";
>> + linux,code = <KEY_VOLUMEDOWN>;
>> + channel = <0>;
>> + voltage = <392644>;
>> + };
>> + button@60 {
>> + label = "Menu";
>> + linux,code = <KEY_MENU>;
>> + channel = <0>;
>> + voltage = <601151>;
>> + };
>> + button@80 {
>> + label = "Enter";
>> + linux,code = <KEY_ENTER>;
>> + channel = <0>;
>> + voltage = <795090>;
>> + };
>> + button@98 {
>> + label = "Home";
>> + linux,code = <KEY_HOME>;
>> + channel = <0>;
>> + voltage = <987387>;
>> + };
>> + };
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index a20df9b..73d1aef 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -8932,6 +8932,13 @@ 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 <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> +L: linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.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 <kda-u1c8ncikuMvVAZt0uhVF+Ni2O/JbrIOy@public.gmane.org>
>> L: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
>> index a3958c6..2d11b44 100644
>> --- 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
>> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
>> index 0a33456..a35269a 100644
>> --- a/drivers/input/keyboard/Makefile
>> +++ b/drivers/input/keyboard/Makefile
>> @@ -53,6 +53,7 @@ obj-$(CONFIG_KEYBOARD_SPEAR) += spear-keyboard.o
>> obj-$(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
>> diff --git a/drivers/input/keyboard/sun4i-lradc-keys.c b/drivers/input/keyboard/sun4i-lradc-keys.c
>> new file mode 100644
>> index 0000000..63a1aff
>> --- /dev/null
>> +++ b/drivers/input/keyboard/sun4i-lradc-keys.c
>> @@ -0,0 +1,259 @@
>> +/*
>> + * Allwinner sun4i low res adc attached tablet keys driver
>> + *
>> + * Copyright (C) 2014 Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> + *
>> + * 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 <linux/err.h>
>> +#include <linux/init.h>
>> +#include <linux/input.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/module.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/slab.h>
>> +
>> +#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-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-lradc-keys", },
>> + { /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, sun4i_lradc_of_match);
>> +
>> +static struct platform_driver sun4i_lradc_driver = {
>> + .driver = {
>> + .owner = THIS_MODULE,
>
> You can drop the owner field, it's already filled by
> module_platform_driver.

Will fix for the next version.

>
>> + .name = "sun4i-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 <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>");
>> +MODULE_LICENSE("GPL");
>> --
>> 2.1.0
>>
>
> Looking good otherwise, thanks!

Thanks for the review.

Regards,

Hans

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