/* * STMicroelectronics STMPE811 Touchscreen Driver * * (C) 2010 Luotao Fu * All rights reserved. * * 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. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include /* Register layouts and functionalities are identical on all stmpexxx variants * with touchscreen controller */ #define STMPE_REG_INT_STA 0x0B #define STMPE_REG_ADC_CTRL1 0x20 #define STMPE_REG_ADC_CTRL2 0x21 #define STMPE_REG_TSC_CTRL 0x40 #define STMPE_REG_TSC_CFG 0x41 #define STMPE_REG_FIFO_TH 0x4A #define STMPE_REG_FIFO_STA 0x4B #define STMPE_REG_FIFO_SIZE 0x4C #define STMPE_REG_TSC_DATA_XYZ 0x52 #define STMPE_REG_TSC_FRACTION_Z 0x56 #define STMPE_REG_TSC_I_DRIVE 0x58 #define OP_MOD_XYZ 0 #define STMPE_TSC_CTRL_TSC_EN (1<<0) #define STMPE_FIFO_STA_RESET (1<<0) #define STMPE_IRQ_TOUCH_DET 0 #define SAMPLE_TIME(x) ((x & 0xf) << 4) #define MOD_12B(x) ((x & 0x1) << 3) #define REF_SEL(x) ((x & 0x1) << 1) #define ADC_FREQ(x) (x & 0x3) #define AVE_CTRL(x) ((x & 0x3) << 6) #define DET_DELAY(x) ((x & 0x7) << 3) #define SETTLING(x) (x & 0x7) #define FRACTION_Z(x) (x & 0x7) #define I_DRIVE(x) (x & 0x1) #define OP_MODE(x) ((x & 0x7) << 1) #define STMPE_TS_NAME "stmpe-ts" #define XY_MASK 0xfff /** * struct stmpe_touch - stmpe811 touch screen controller state * @stmpe: pointer back to STMPE MFD container * @idev: registered input device * @work: a work item used to scan the device * @dev: a pointer back to the MFD cell struct device* * @sample_time: ADC converstion time in number of clock. * (0 -> 36 clocks, 1 -> 44 clocks, 2 -> 56 clocks, 3 -> 64 clocks, * 4 -> 80 clocks, 5 -> 96 clocks, 6 -> 144 clocks), * recommended is 4. * @mod_12b: ADC Bit mode (0 -> 10bit ADC, 1 -> 12bit ADC) * @ref_sel: ADC reference source * (0 -> internal reference, 1 -> external reference) * @adc_freq: ADC Clock speed * (0 -> 1.625 MHz, 1 -> 3.25 MHz, 2 || 3 -> 6.5 MHz) * @ave_ctrl: Sample average control * (0 -> 1 sample, 1 -> 2 samples, 2 -> 4 samples, 3 -> 8 samples) * @touch_det_delay: Touch detect interrupt delay * (0 -> 10 us, 1 -> 50 us, 2 -> 100 us, 3 -> 500 us, * 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms) * recommended is 3 * @settling: Panel driver settling time * (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3 -> 1 ms, * 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms) * recommended is 2 * @fraction_z: Length of the fractional part in z * (fraction_z ([0..7]) = Count of the fractional part) * recommended is 7 * @i_drive: current limit value of the touchscreen drivers * (0 -> 20 mA typical 35 mA max, 1 -> 50 mA typical 80 mA max) */ struct stmpe_touch { struct stmpe *stmpe; struct input_dev *idev; struct delayed_work work; struct device *dev; u8 sample_time; u8 mod_12b; u8 ref_sel; u8 adc_freq; u8 ave_ctrl; u8 touch_det_delay; u8 settling; u8 fraction_z; u8 i_drive; }; static int __stmpe_reset_fifo(struct stmpe *stmpe) { int ret; ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET); if (ret) return ret; return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, STMPE_FIFO_STA_RESET, 0); } static void stmpe_work(struct work_struct *work) { int int_sta; u32 timeout = 40; struct stmpe_touch *ts = container_of(work, struct stmpe_touch, work.work); int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); /* * touch_det sometimes get desasserted or just get stuck. This appears * to be a silicon bug, We still have to clearify this with the * manufacture. As a workaround We release the key anyway if the * touch_det keeps coming in after 4ms, while the FIFO contains no value * during the whole time. */ while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) { timeout--; int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); udelay(100); } /* reset the FIFO before we report release event */ __stmpe_reset_fifo(ts->stmpe); input_report_abs(ts->idev, ABS_PRESSURE, 0); input_report_key(ts->idev, BTN_TOUCH, 0); input_sync(ts->idev); } static irqreturn_t stmpe_ts_handler(int irq, void *data) { u8 data_set[4]; int x, y, z; struct stmpe_touch *ts = data; /* * Cancel scheduled polling for release if we have new value * available. Wait if the polling is already running. */ cancel_delayed_work_sync(&ts->work); /* * The FIFO sometimes just crashes and stops generating interrupts. This * appears to be a silicon bug. We still have to clearify this with * the manufacture. As a workaround we disable the TSC while we are * collecting data and flush the FIFO after reading */ stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, STMPE_TSC_CTRL_TSC_EN, 0); stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set); x = (data_set[0] << 4) | (data_set[1] >> 4); y = ((data_set[1] & 0xf) << 8) | data_set[2]; z = data_set[3]; input_report_abs(ts->idev, ABS_X, x); input_report_abs(ts->idev, ABS_Y, y); input_report_abs(ts->idev, ABS_PRESSURE, z); input_report_key(ts->idev, BTN_TOUCH, 1); input_sync(ts->idev); /* flush the FIFO after we have read out our values. */ __stmpe_reset_fifo(ts->stmpe); /* reenable the tsc */ stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); /* start polling for touch_det to detect release */ schedule_delayed_work(&ts->work, msecs_to_jiffies(50)); return IRQ_HANDLED; } static int stmpe_init_hw(struct stmpe_touch *ts) { int ret; u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask; struct stmpe *stmpe = ts->stmpe; struct device *dev = ts->dev; ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); if (ret) { dev_err(dev, "Could not enable clock for ADC and TS\n"); return ret; } adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) | REF_SEL(ts->ref_sel); adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff); ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1, adc_ctrl1_mask, adc_ctrl1); if (ret) { dev_err(dev, "Could not setup ADC\n"); return ret; } ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2, ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq)); if (ret) { dev_err(dev, "Could not setup ADC\n"); return ret; } tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) | SETTLING(ts->settling); tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff); ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg); if (ret) { dev_err(dev, "Could not config touch\n"); return ret; } ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z, FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z)); if (ret) { dev_err(dev, "Could not config touch\n"); return ret; } ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE, I_DRIVE(0xff), I_DRIVE(ts->i_drive)); if (ret) { dev_err(dev, "Could not config touch\n"); return ret; } /* set FIFO to 1 for single point reading */ ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1); if (ret) { dev_err(dev, "Could not set FIFO\n"); return ret; } ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL, OP_MODE(0xff), OP_MODE(OP_MOD_XYZ)); if (ret) { dev_err(dev, "Could not set mode\n"); return ret; } return 0; } static int stmpe_ts_open(struct input_dev *dev) { struct stmpe_touch *ts = input_get_drvdata(dev); int ret = 0; ret = __stmpe_reset_fifo(ts->stmpe); if (ret) return ret; return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); } static void stmpe_ts_close(struct input_dev *dev) { struct stmpe_touch *ts = input_get_drvdata(dev); cancel_delayed_work_sync(&ts->work); stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, STMPE_TSC_CTRL_TSC_EN, 0); } static void stmpe_ts_get_platform_info(struct platform_device *pdev, struct stmpe_touch *ts) { struct device_node *np = pdev->dev.of_node; u32 val; if (np) { if (!of_property_read_u32(np, "st,sample-time", &val)) ts->sample_time = val; if (!of_property_read_u32(np, "st,mod-12b", &val)) ts->mod_12b = val; if (!of_property_read_u32(np, "st,ref-sel", &val)) ts->ref_sel = val; if (!of_property_read_u32(np, "st,adc-freq", &val)) ts->adc_freq = val; if (!of_property_read_u32(np, "st,ave-ctrl", &val)) ts->ave_ctrl = val; if (!of_property_read_u32(np, "st,touch-det-delay", &val)) ts->touch_det_delay = val; if (!of_property_read_u32(np, "st,settling", &val)) ts->settling = val; if (!of_property_read_u32(np, "st,fraction-z", &val)) ts->fraction_z = val; if (!of_property_read_u32(np, "st,i-drive", &val)) ts->i_drive = val; } } static int stmpe_input_probe(struct platform_device *pdev) { struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent); struct stmpe_touch *ts; struct input_dev *idev; int error; int ts_irq; ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); if (ts_irq < 0) return ts_irq; ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL); if (!ts) return -ENOMEM; idev = devm_input_allocate_device(&pdev->dev); if (!idev) return -ENOMEM; platform_set_drvdata(pdev, ts); ts->stmpe = stmpe; ts->idev = idev; ts->dev = &pdev->dev; stmpe_ts_get_platform_info(pdev, ts); INIT_DELAYED_WORK(&ts->work, stmpe_work); error = devm_request_threaded_irq(&pdev->dev, ts_irq, NULL, stmpe_ts_handler, IRQF_ONESHOT, STMPE_TS_NAME, ts); if (error) { dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq); return error; } error = stmpe_init_hw(ts); if (error) return error; idev->name = STMPE_TS_NAME; idev->phys = STMPE_TS_NAME"/input0"; idev->id.bustype = BUS_I2C; idev->open = stmpe_ts_open; idev->close = stmpe_ts_close; input_set_drvdata(idev, ts); input_set_capability(idev, EV_KEY, BTN_TOUCH); input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0); input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0); input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0); error = input_register_device(idev); if (error) { dev_err(&pdev->dev, "Could not register input device\n"); return error; } return 0; } static int stmpe_ts_remove(struct platform_device *pdev) { struct stmpe_touch *ts = platform_get_drvdata(pdev); stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN); return 0; } static struct platform_driver stmpe_ts_driver = { .driver = { .name = STMPE_TS_NAME, }, .probe = stmpe_input_probe, .remove = stmpe_ts_remove, }; module_platform_driver(stmpe_ts_driver); static const struct of_device_id stmpe_ts_ids[] = { { .compatible = "st,stmpe-ts", }, { }, }; MODULE_DEVICE_TABLE(of, stmpe_ts_ids); MODULE_AUTHOR("Luotao Fu "); MODULE_DESCRIPTION("STMPEXXX touchscreen driver"); MODULE_LICENSE("GPL");