--- /dev/null
+From 3f8fd9b9e2daefb7be4c46369f86af1c7bb2f1ca Mon Sep 17 00:00:00 2001
+From: Hans de Goede <hdegoede@redhat.com>
+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. The devicetree properties are already
+prefixed with chan0 as preparation for chan1 support in the future.
+
+This has been tested on an olimex a10s-olinuxino-micro, a13-olinuxino, and
+a20-olinuxino-micro.
+
+Signed-off-by: Hans de Goede <hdegoede@redhat.com>
+---
+ .../devicetree/bindings/input/sun4i-lradc-keys.txt | 22 ++
+ drivers/input/keyboard/Kconfig | 10 +
+ drivers/input/keyboard/Makefile | 1 +
+ drivers/input/keyboard/sun4i-lradc-keys.c | 243 +++++++++++++++++++++
+ 4 files changed, 276 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..7801264
+--- /dev/null
++++ b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
+@@ -0,0 +1,22 @@
++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
++ - allwinner,chan0-step: step in mV between keys must be 150 or 200
++ - linux,chan0-keycodes: array of dt-bindings/input/input.h KEY_ codes
++
++Example:
++
++#include <dt-bindings/input/input.h>
++
++ lradc: lradc@01c22800 {
++ compatible = "allwinner,sun4i-lradc-keys";
++ reg = <0x01c22800 0x100>;
++ interrupts = <31>;
++ allwinner,chan0-step = <200>;
++ linux,chan0-keycodes = <KEY_VOLUMEUP KEY_VOLUMEDOWN
++ KEY_MENU KEY_ENTER KEY_HOME>;
++ };
+diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
+index a673c9f..d8a51cd 100644
+--- a/drivers/input/keyboard/Kconfig
++++ b/drivers/input/keyboard/Kconfig
+@@ -544,6 +544,16 @@ 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 a699b61..f3265bd 100644
+--- a/drivers/input/keyboard/Makefile
++++ b/drivers/input/keyboard/Makefile
+@@ -50,6 +50,7 @@ obj-$(CONFIG_KEYBOARD_SH_KEYSC) += sh_keysc.o
+ obj-$(CONFIG_KEYBOARD_SPEAR) += spear-keyboard.o
+ obj-$(CONFIG_KEYBOARD_STMPE) += stmpe-keypad.o
+ obj-$(CONFIG_KEYBOARD_STOWAWAY) += stowaway.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..5c55e17
+--- /dev/null
++++ b/drivers/input/keyboard/sun4i-lradc-keys.c
+@@ -0,0 +1,243 @@
++/*
++ * Allwinner sun4i low res adc attached tablet keys driver
++ *
++ * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.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; 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 chan0 since there
++ * are no boards known to use chan1. The devicetree properties are already
++ * prefixed with chan0 as preparation for chan1 support in the future.
++ */
++
++#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/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)
++
++#define MAX_KEYS 13
++
++/* Lookup table to map the adc val to a keycode index for 150 mv step size */
++static const u8 adc_val_to_key_index_step150[64] = {
++ 0, 0, 0,
++ 1, 1, 1, 1, 1,
++ 2, 2, 2, 2, 2,
++ 3, 3, 3, 3,
++ 4, 4, 4, 4, 4,
++ 5, 5, 5, 5, 5,
++ 6, 6, 6, 6, 6,
++ 7, 7, 7, 7,
++ 8, 8, 8, 8, 8,
++ 9, 9, 9, 9, 9,
++ 10, 10, 10, 10,
++ 11, 11, 11, 11,
++ 12, 12, 12, 12, 12, 12, 12, 12, 12, 12
++};
++
++/* Lookup table to map the adc val to a keycode index for 200 mv step size */
++static const u8 adc_val_to_key_index_step200[64] = {
++ 0, 0, 0, 0, 0, 0, 0, 0,
++ 1, 1, 1, 1, 1, 1, 1,
++ 2, 2, 2, 2, 2, 2, 2,
++ 3, 3, 3, 3, 3, 3,
++ 4, 4, 4, 4, 4, 4,
++ 5, 5, 5, 5, 5, 5,
++ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
++ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
++};
++
++struct sun4i_lradc_data {
++ struct device *dev;
++ struct input_dev *input;
++ void __iomem *base;
++ u32 chan0_step;
++ u32 chan0_keycode;
++ u32 chan0_keycodes[MAX_KEYS];
++};
++
++static irqreturn_t sun4i_lradc_irq(int irq, void *dev_id)
++{
++ struct sun4i_lradc_data *lradc = dev_id;
++ u32 ints, val;
++
++ 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);
++ if (lradc->chan0_step == 150)
++ val = adc_val_to_key_index_step150[val];
++ else
++ val = adc_val_to_key_index_step200[val];
++
++ lradc->chan0_keycode = lradc->chan0_keycodes[val];
++ 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);
++
++ /*
++ * Set sample time to 16 ms / 62.5 Hz. Wait 2 * 16 ms for key to
++ * stabilize on press, wait (1 + 1) * 16 ms for key release
++ */
++ writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
++ SAMPLE_RATE(2) | 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);
++}
++
++static int sun4i_lradc_probe(struct platform_device *pdev)
++{
++ struct sun4i_lradc_data *lradc;
++ struct device *dev = &pdev->dev;
++ struct device_node *np = dev->of_node;
++ int i, ret;
++
++ lradc = devm_kzalloc(dev, sizeof(struct sun4i_lradc_data), GFP_KERNEL);
++ if (!lradc)
++ return -ENOMEM;
++
++ ret = of_property_read_u32(np, "allwinner,chan0-step",
++ &lradc->chan0_step);
++ if (ret || (lradc->chan0_step != 150 && lradc->chan0_step != 200)) {
++ dev_err(dev, "Invalid allwinner,chan0-step dt-property\n");
++ return -EINVAL;
++ }
++
++ for (i = 0; i < MAX_KEYS; i++)
++ of_property_read_u32_index(np, "linux,chan0-keycodes",
++ i, &lradc->chan0_keycodes[i]);
++
++ 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 < MAX_KEYS; i++)
++ set_bit(lradc->chan0_keycodes[i], 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,
++ .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@redhat.com>");
++MODULE_LICENSE("GPL");
+--
+2.0.3
+
projects / openwrt / openwrt.git / blobdiff