/* * Allwinner sunxi resistive touchscreen controller driver * * Copyright (C) 2013 - 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. */ /* * 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 #include #include #include #include #include #include #include #include #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; }; static irqreturn_t sun4i_ts_irq(int irq, void *dev_id) { struct sun4i_ts_data *ts = dev_id; u32 reg_val, x, y; reg_val = readl(ts->base + TP_INT_FIFOS); 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); } 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 data and up irqs */ writel(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 IRQs */ writel(0, ts->base + TP_INT_FIFOC); } static int sun4i_ts_probe(struct platform_device *pdev) { struct sun4i_ts_data *ts; struct device *dev = &pdev->dev; int error; ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL); if (!ts) return -ENOMEM; ts->dev = dev; ts->ignore_fifo_data = true; 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); error = input_register_device(ts->input); if (error) return error; platform_set_drvdata(pdev, ts); 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, }; module_platform_driver(sun4i_ts_driver); MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver"); MODULE_AUTHOR("Hans de Goede "); MODULE_LICENSE("GPL");