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Based on 3 normalized pattern(s): 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 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 [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] 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 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 [author] [graeme] [gregory] [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema] [hk] [hemahk]@[ti] [com] 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1105 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
306 lines
8 KiB
C
306 lines
8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Allwinner sun4i low res adc attached tablet keys driver
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*
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* Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
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*/
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/*
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* Allwinnner sunxi SoCs have a lradc which is specifically designed to have
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* various (tablet) keys (ie home, back, search, etc). attached to it using
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* a resistor network. This driver is for the keys on such boards.
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*
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* There are 2 channels, currently this driver only supports channel 0 since
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* there are no boards known to use channel 1.
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*/
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/input.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of_platform.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/consumer.h>
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#include <linux/slab.h>
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#define LRADC_CTRL 0x00
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#define LRADC_INTC 0x04
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#define LRADC_INTS 0x08
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#define LRADC_DATA0 0x0c
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#define LRADC_DATA1 0x10
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/* LRADC_CTRL bits */
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#define FIRST_CONVERT_DLY(x) ((x) << 24) /* 8 bits */
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#define CHAN_SELECT(x) ((x) << 22) /* 2 bits */
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#define CONTINUE_TIME_SEL(x) ((x) << 16) /* 4 bits */
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#define KEY_MODE_SEL(x) ((x) << 12) /* 2 bits */
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#define LEVELA_B_CNT(x) ((x) << 8) /* 4 bits */
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#define HOLD_KEY_EN(x) ((x) << 7)
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#define HOLD_EN(x) ((x) << 6)
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#define LEVELB_VOL(x) ((x) << 4) /* 2 bits */
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#define SAMPLE_RATE(x) ((x) << 2) /* 2 bits */
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#define ENABLE(x) ((x) << 0)
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/* LRADC_INTC and LRADC_INTS bits */
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#define CHAN1_KEYUP_IRQ BIT(12)
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#define CHAN1_ALRDY_HOLD_IRQ BIT(11)
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#define CHAN1_HOLD_IRQ BIT(10)
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#define CHAN1_KEYDOWN_IRQ BIT(9)
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#define CHAN1_DATA_IRQ BIT(8)
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#define CHAN0_KEYUP_IRQ BIT(4)
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#define CHAN0_ALRDY_HOLD_IRQ BIT(3)
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#define CHAN0_HOLD_IRQ BIT(2)
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#define CHAN0_KEYDOWN_IRQ BIT(1)
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#define CHAN0_DATA_IRQ BIT(0)
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/* struct lradc_variant - Describe sun4i-a10-lradc-keys hardware variant
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* @divisor_numerator: The numerator of lradc Vref internally divisor
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* @divisor_denominator: The denominator of lradc Vref internally divisor
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*/
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struct lradc_variant {
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u8 divisor_numerator;
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u8 divisor_denominator;
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};
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static const struct lradc_variant lradc_variant_a10 = {
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.divisor_numerator = 2,
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.divisor_denominator = 3
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};
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static const struct lradc_variant r_lradc_variant_a83t = {
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.divisor_numerator = 3,
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.divisor_denominator = 4
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};
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struct sun4i_lradc_keymap {
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u32 voltage;
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u32 keycode;
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};
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struct sun4i_lradc_data {
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struct device *dev;
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struct input_dev *input;
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void __iomem *base;
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struct regulator *vref_supply;
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struct sun4i_lradc_keymap *chan0_map;
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const struct lradc_variant *variant;
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u32 chan0_map_count;
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u32 chan0_keycode;
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u32 vref;
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};
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static irqreturn_t sun4i_lradc_irq(int irq, void *dev_id)
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{
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struct sun4i_lradc_data *lradc = dev_id;
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u32 i, ints, val, voltage, diff, keycode = 0, closest = 0xffffffff;
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ints = readl(lradc->base + LRADC_INTS);
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/*
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* lradc supports only one keypress at a time, release does not give
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* any info as to which key was released, so we cache the keycode.
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*/
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if (ints & CHAN0_KEYUP_IRQ) {
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input_report_key(lradc->input, lradc->chan0_keycode, 0);
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lradc->chan0_keycode = 0;
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}
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if ((ints & CHAN0_KEYDOWN_IRQ) && lradc->chan0_keycode == 0) {
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val = readl(lradc->base + LRADC_DATA0) & 0x3f;
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voltage = val * lradc->vref / 63;
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for (i = 0; i < lradc->chan0_map_count; i++) {
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diff = abs(lradc->chan0_map[i].voltage - voltage);
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if (diff < closest) {
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closest = diff;
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keycode = lradc->chan0_map[i].keycode;
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}
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}
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lradc->chan0_keycode = keycode;
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input_report_key(lradc->input, lradc->chan0_keycode, 1);
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}
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input_sync(lradc->input);
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writel(ints, lradc->base + LRADC_INTS);
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return IRQ_HANDLED;
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}
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static int sun4i_lradc_open(struct input_dev *dev)
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{
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struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
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int error;
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error = regulator_enable(lradc->vref_supply);
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if (error)
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return error;
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lradc->vref = regulator_get_voltage(lradc->vref_supply) *
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lradc->variant->divisor_numerator /
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lradc->variant->divisor_denominator;
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/*
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* Set sample time to 4 ms / 250 Hz. Wait 2 * 4 ms for key to
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* stabilize on press, wait (1 + 1) * 4 ms for key release
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*/
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writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
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SAMPLE_RATE(0) | ENABLE(1), lradc->base + LRADC_CTRL);
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writel(CHAN0_KEYUP_IRQ | CHAN0_KEYDOWN_IRQ, lradc->base + LRADC_INTC);
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return 0;
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}
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static void sun4i_lradc_close(struct input_dev *dev)
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{
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struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
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/* Disable lradc, leave other settings unchanged */
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writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
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SAMPLE_RATE(2), lradc->base + LRADC_CTRL);
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writel(0, lradc->base + LRADC_INTC);
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regulator_disable(lradc->vref_supply);
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}
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static int sun4i_lradc_load_dt_keymap(struct device *dev,
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struct sun4i_lradc_data *lradc)
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{
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struct device_node *np, *pp;
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int i;
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int error;
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np = dev->of_node;
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if (!np)
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return -EINVAL;
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lradc->chan0_map_count = of_get_child_count(np);
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if (lradc->chan0_map_count == 0) {
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dev_err(dev, "keymap is missing in device tree\n");
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return -EINVAL;
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}
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lradc->chan0_map = devm_kmalloc_array(dev, lradc->chan0_map_count,
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sizeof(struct sun4i_lradc_keymap),
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GFP_KERNEL);
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if (!lradc->chan0_map)
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return -ENOMEM;
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i = 0;
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for_each_child_of_node(np, pp) {
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struct sun4i_lradc_keymap *map = &lradc->chan0_map[i];
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u32 channel;
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error = of_property_read_u32(pp, "channel", &channel);
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if (error || channel != 0) {
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dev_err(dev, "%pOFn: Inval channel prop\n", pp);
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return -EINVAL;
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}
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error = of_property_read_u32(pp, "voltage", &map->voltage);
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if (error) {
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dev_err(dev, "%pOFn: Inval voltage prop\n", pp);
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return -EINVAL;
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}
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error = of_property_read_u32(pp, "linux,code", &map->keycode);
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if (error) {
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dev_err(dev, "%pOFn: Inval linux,code prop\n", pp);
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return -EINVAL;
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}
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i++;
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}
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return 0;
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}
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static int sun4i_lradc_probe(struct platform_device *pdev)
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{
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struct sun4i_lradc_data *lradc;
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struct device *dev = &pdev->dev;
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int i;
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int error;
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lradc = devm_kzalloc(dev, sizeof(struct sun4i_lradc_data), GFP_KERNEL);
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if (!lradc)
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return -ENOMEM;
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error = sun4i_lradc_load_dt_keymap(dev, lradc);
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if (error)
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return error;
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lradc->variant = of_device_get_match_data(&pdev->dev);
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if (!lradc->variant) {
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dev_err(&pdev->dev, "Missing sun4i-a10-lradc-keys variant\n");
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return -EINVAL;
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}
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lradc->vref_supply = devm_regulator_get(dev, "vref");
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if (IS_ERR(lradc->vref_supply))
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return PTR_ERR(lradc->vref_supply);
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lradc->dev = dev;
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lradc->input = devm_input_allocate_device(dev);
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if (!lradc->input)
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return -ENOMEM;
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lradc->input->name = pdev->name;
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lradc->input->phys = "sun4i_lradc/input0";
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lradc->input->open = sun4i_lradc_open;
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lradc->input->close = sun4i_lradc_close;
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lradc->input->id.bustype = BUS_HOST;
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lradc->input->id.vendor = 0x0001;
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lradc->input->id.product = 0x0001;
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lradc->input->id.version = 0x0100;
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__set_bit(EV_KEY, lradc->input->evbit);
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for (i = 0; i < lradc->chan0_map_count; i++)
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__set_bit(lradc->chan0_map[i].keycode, lradc->input->keybit);
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input_set_drvdata(lradc->input, lradc);
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lradc->base = devm_ioremap_resource(dev,
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platform_get_resource(pdev, IORESOURCE_MEM, 0));
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if (IS_ERR(lradc->base))
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return PTR_ERR(lradc->base);
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error = devm_request_irq(dev, platform_get_irq(pdev, 0),
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sun4i_lradc_irq, 0,
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"sun4i-a10-lradc-keys", lradc);
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if (error)
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return error;
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error = input_register_device(lradc->input);
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if (error)
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return error;
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return 0;
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}
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static const struct of_device_id sun4i_lradc_of_match[] = {
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{ .compatible = "allwinner,sun4i-a10-lradc-keys",
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.data = &lradc_variant_a10 },
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{ .compatible = "allwinner,sun8i-a83t-r-lradc",
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.data = &r_lradc_variant_a83t },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, sun4i_lradc_of_match);
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static struct platform_driver sun4i_lradc_driver = {
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.driver = {
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.name = "sun4i-a10-lradc-keys",
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.of_match_table = of_match_ptr(sun4i_lradc_of_match),
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},
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.probe = sun4i_lradc_probe,
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};
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module_platform_driver(sun4i_lradc_driver);
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MODULE_DESCRIPTION("Allwinner sun4i low res adc attached tablet keys driver");
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MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
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MODULE_LICENSE("GPL");
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