diff options
Diffstat (limited to 'drivers/input/touchscreen/sun4i-ts.c')
| -rw-r--r-- | drivers/input/touchscreen/sun4i-ts.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/sun4i-ts.c b/drivers/input/touchscreen/sun4i-ts.c new file mode 100644 index 00000000000..2ba82602495 --- /dev/null +++ b/drivers/input/touchscreen/sun4i-ts.c @@ -0,0 +1,339 @@ +/* + * Allwinner sunxi resistive touchscreen controller driver + * + * Copyright (C) 2013 - 2014 Hans de Goede <hdegoede@redhat.com> + * + * The hwmon parts are based on work by Corentin LABBE which is: + * Copyright (C) 2013 Corentin LABBE <clabbe.montjoie@gmail.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. + */ + +/* + * The sun4i-ts controller is capable of detecting a second touch, but when a + * second touch is present then the accuracy becomes so bad the reported touch + * location is not useable. + * + * The original android driver contains some complicated heuristics using the + * aprox. distance between the 2 touches to see if the user is making a pinch + * open / close movement, and then reports emulated multi-touch events around + * the last touch coordinate (as the dual-touch coordinates are worthless). + * + * These kinds of heuristics are just asking for trouble (and don't belong + * in the kernel). So this driver offers straight forward, reliable single + * touch functionality only. + */ + +#include <linux/err.h> +#include <linux/hwmon.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 TP_CTRL0 0x00 +#define TP_CTRL1 0x04 +#define TP_CTRL2 0x08 +#define TP_CTRL3 0x0c +#define TP_INT_FIFOC 0x10 +#define TP_INT_FIFOS 0x14 +#define TP_TPR 0x18 +#define TP_CDAT 0x1c +#define TEMP_DATA 0x20 +#define TP_DATA 0x24 + +/* TP_CTRL0 bits */ +#define ADC_FIRST_DLY(x) ((x) << 24) /* 8 bits */ +#define ADC_FIRST_DLY_MODE(x) ((x) << 23) +#define ADC_CLK_SEL(x) ((x) << 22) +#define ADC_CLK_DIV(x) ((x) << 20) /* 3 bits */ +#define FS_DIV(x) ((x) << 16) /* 4 bits */ +#define T_ACQ(x) ((x) << 0) /* 16 bits */ + +/* TP_CTRL1 bits */ +#define STYLUS_UP_DEBOUN(x) ((x) << 12) /* 8 bits */ +#define STYLUS_UP_DEBOUN_EN(x) ((x) << 9) +#define TOUCH_PAN_CALI_EN(x) ((x) << 6) +#define TP_DUAL_EN(x) ((x) << 5) +#define TP_MODE_EN(x) ((x) << 4) +#define TP_ADC_SELECT(x) ((x) << 3) +#define ADC_CHAN_SELECT(x) ((x) << 0) /* 3 bits */ + +/* TP_CTRL2 bits */ +#define TP_SENSITIVE_ADJUST(x) ((x) << 28) /* 4 bits */ +#define TP_MODE_SELECT(x) ((x) << 26) /* 2 bits */ +#define PRE_MEA_EN(x) ((x) << 24) +#define PRE_MEA_THRE_CNT(x) ((x) << 0) /* 24 bits */ + +/* TP_CTRL3 bits */ +#define FILTER_EN(x) ((x) << 2) +#define FILTER_TYPE(x) ((x) << 0) /* 2 bits */ + +/* TP_INT_FIFOC irq and fifo mask / control bits */ +#define TEMP_IRQ_EN(x) ((x) << 18) +#define OVERRUN_IRQ_EN(x) ((x) << 17) +#define DATA_IRQ_EN(x) ((x) << 16) +#define TP_DATA_XY_CHANGE(x) ((x) << 13) +#define FIFO_TRIG(x) ((x) << 8) /* 5 bits */ +#define DATA_DRQ_EN(x) ((x) << 7) +#define FIFO_FLUSH(x) ((x) << 4) +#define TP_UP_IRQ_EN(x) ((x) << 1) +#define TP_DOWN_IRQ_EN(x) ((x) << 0) + +/* TP_INT_FIFOS irq and fifo status bits */ +#define TEMP_DATA_PENDING BIT(18) +#define FIFO_OVERRUN_PENDING BIT(17) +#define FIFO_DATA_PENDING BIT(16) +#define TP_IDLE_FLG BIT(2) +#define TP_UP_PENDING BIT(1) +#define TP_DOWN_PENDING BIT(0) + +/* TP_TPR bits */ +#define TEMP_ENABLE(x) ((x) << 16) +#define TEMP_PERIOD(x) ((x) << 0) /* t = x * 256 * 16 / clkin */ + +struct sun4i_ts_data { + struct device *dev; + struct input_dev *input; + void __iomem *base; + unsigned int irq; + bool ignore_fifo_data; + int temp_data; +}; + +static void sun4i_ts_irq_handle_input(struct sun4i_ts_data *ts, u32 reg_val) +{ + u32 x, y; + + if (reg_val & FIFO_DATA_PENDING) { + x = readl(ts->base + TP_DATA); + y = readl(ts->base + TP_DATA); + /* The 1st location reported after an up event is unreliable */ + if (!ts->ignore_fifo_data) { + input_report_abs(ts->input, ABS_X, x); + input_report_abs(ts->input, ABS_Y, y); + /* + * The hardware has a separate down status bit, but + * that gets set before we get the first location, + * resulting in reporting a click on the old location. + */ + input_report_key(ts->input, BTN_TOUCH, 1); + input_sync(ts->input); + } else { + ts->ignore_fifo_data = false; + } + } + + if (reg_val & TP_UP_PENDING) { + ts->ignore_fifo_data = true; + input_report_key(ts->input, BTN_TOUCH, 0); + input_sync(ts->input); + } +} + +static irqreturn_t sun4i_ts_irq(int irq, void *dev_id) +{ + struct sun4i_ts_data *ts = dev_id; + u32 reg_val; + + reg_val = readl(ts->base + TP_INT_FIFOS); + + if (reg_val & TEMP_DATA_PENDING) + ts->temp_data = readl(ts->base + TEMP_DATA); + + if (ts->input) + sun4i_ts_irq_handle_input(ts, reg_val); + + writel(reg_val, ts->base + TP_INT_FIFOS); + + return IRQ_HANDLED; +} + +static int sun4i_ts_open(struct input_dev *dev) +{ + struct sun4i_ts_data *ts = input_get_drvdata(dev); + + /* Flush, set trig level to 1, enable temp, data and up irqs */ + writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) | + TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC); + + return 0; +} + +static void sun4i_ts_close(struct input_dev *dev) +{ + struct sun4i_ts_data *ts = input_get_drvdata(dev); + + /* Deactivate all input IRQs */ + writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC); +} + +static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, + char *buf) +{ + struct sun4i_ts_data *ts = dev_get_drvdata(dev); + + /* No temp_data until the first irq */ + if (ts->temp_data == -1) + return -EAGAIN; + + return sprintf(buf, "%d\n", (ts->temp_data - 1447) * 100); +} + +static ssize_t show_temp_label(struct device *dev, + struct device_attribute *devattr, char *buf) +{ + return sprintf(buf, "SoC temperature\n"); +} + +static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL); +static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL); + +static struct attribute *sun4i_ts_attrs[] = { + &dev_attr_temp1_input.attr, + &dev_attr_temp1_label.attr, + NULL +}; +ATTRIBUTE_GROUPS(sun4i_ts); + +static int sun4i_ts_probe(struct platform_device *pdev) +{ + struct sun4i_ts_data *ts; + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct device *hwmon; + int error; + bool ts_attached; + + ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL); + if (!ts) + return -ENOMEM; + + ts->dev = dev; + ts->ignore_fifo_data = true; + ts->temp_data = -1; + + ts_attached = of_property_read_bool(np, "allwinner,ts-attached"); + if (ts_attached) { + ts->input = devm_input_allocate_device(dev); + if (!ts->input) + return -ENOMEM; + + ts->input->name = pdev->name; + ts->input->phys = "sun4i_ts/input0"; + ts->input->open = sun4i_ts_open; + ts->input->close = sun4i_ts_close; + ts->input->id.bustype = BUS_HOST; + ts->input->id.vendor = 0x0001; + ts->input->id.product = 0x0001; + ts->input->id.version = 0x0100; + ts->input->evbit[0] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS); + __set_bit(BTN_TOUCH, ts->input->keybit); + input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0); + input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0); + input_set_drvdata(ts->input, ts); + } + + ts->base = devm_ioremap_resource(dev, + platform_get_resource(pdev, IORESOURCE_MEM, 0)); + if (IS_ERR(ts->base)) + return PTR_ERR(ts->base); + + ts->irq = platform_get_irq(pdev, 0); + error = devm_request_irq(dev, ts->irq, sun4i_ts_irq, 0, "sun4i-ts", ts); + if (error) + return error; + + /* + * Select HOSC clk, clkin = clk / 6, adc samplefreq = clkin / 8192, + * t_acq = clkin / (16 * 64) + */ + writel(ADC_CLK_SEL(0) | ADC_CLK_DIV(2) | FS_DIV(7) | T_ACQ(63), + ts->base + TP_CTRL0); + + /* + * sensitive_adjust = 15 : max, which is not all that sensitive, + * tp_mode = 0 : only x and y coordinates, as we don't use dual touch + */ + writel(TP_SENSITIVE_ADJUST(15) | TP_MODE_SELECT(0), + ts->base + TP_CTRL2); + + /* Enable median filter, type 1 : 5/3 */ + writel(FILTER_EN(1) | FILTER_TYPE(1), ts->base + TP_CTRL3); + + /* Enable temperature measurement, period 1953 (2 seconds) */ + writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR); + + /* + * Set stylus up debounce to aprox 10 ms, enable debounce, and + * finally enable tp mode. + */ + writel(STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1) | TP_MODE_EN(1), + ts->base + TP_CTRL1); + + hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts", + ts, sun4i_ts_groups); + if (IS_ERR(hwmon)) + return PTR_ERR(hwmon); + + writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC); + + if (ts_attached) { + error = input_register_device(ts->input); + if (error) { + writel(0, ts->base + TP_INT_FIFOC); + return error; + } + } + + platform_set_drvdata(pdev, ts); + return 0; +} + +static int sun4i_ts_remove(struct platform_device *pdev) +{ + struct sun4i_ts_data *ts = platform_get_drvdata(pdev); + + /* Explicit unregister to avoid open/close changing the imask later */ + if (ts->input) + input_unregister_device(ts->input); + + /* Deactivate all IRQs */ + writel(0, ts->base + TP_INT_FIFOC); + + return 0; +} + +static const struct of_device_id sun4i_ts_of_match[] = { + { .compatible = "allwinner,sun4i-a10-ts", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, sun4i_ts_of_match); + +static struct platform_driver sun4i_ts_driver = { + .driver = { + .owner = THIS_MODULE, + .name = "sun4i-ts", + .of_match_table = of_match_ptr(sun4i_ts_of_match), + }, + .probe = sun4i_ts_probe, + .remove = sun4i_ts_remove, +}; + +module_platform_driver(sun4i_ts_driver); + +MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver"); +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); +MODULE_LICENSE("GPL"); |