diff options
Diffstat (limited to 'drivers/input/touchscreen/stmpe-ts.c')
| -rw-r--r-- | drivers/input/touchscreen/stmpe-ts.c | 379 |
1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c new file mode 100644 index 000000000..25c45c3a3 --- /dev/null +++ b/drivers/input/touchscreen/stmpe-ts.c @@ -0,0 +1,379 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * STMicroelectronics STMPE811 Touchscreen Driver + * + * (C) 2010 Luotao Fu <l.fu@pengutronix.de> + * All rights reserved. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/device.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/input.h> +#include <linux/input/touchscreen.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/workqueue.h> + +#include <linux/mfd/stmpe.h> + +/* Register layouts and functionalities are identical on all stmpexxx variants + * with touchscreen controller + */ +#define STMPE_REG_INT_STA 0x0B +#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 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* + * @prop: Touchscreen properties + * @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; + struct touchscreen_properties prop; + 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]; + + touchscreen_report_pos(ts->idev, &ts->prop, x, y, false); + 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 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; + } + + ret = stmpe811_adc_common_init(stmpe); + if (ret) { + stmpe_disable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); + return ret; + } + + tsc_cfg = STMPE_AVE_CTRL(ts->ave_ctrl) | + STMPE_DET_DELAY(ts->touch_det_delay) | + STMPE_SETTLING(ts->settling); + tsc_cfg_mask = STMPE_AVE_CTRL(0xff) | STMPE_DET_DELAY(0xff) | + STMPE_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, + STMPE_FRACTION_Z(0xff), STMPE_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, + STMPE_I_DRIVE(0xff), STMPE_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, + STMPE_OP_MODE(0xff), STMPE_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->stmpe->sample_time = val; + if (!of_property_read_u32(np, "st,mod-12b", &val)) + ts->stmpe->mod_12b = val; + if (!of_property_read_u32(np, "st,ref-sel", &val)) + ts->stmpe->ref_sel = val; + if (!of_property_read_u32(np, "st,adc-freq", &val)) + ts->stmpe->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); + + touchscreen_parse_properties(idev, false, &ts->prop); + + 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 <l.fu@pengutronix.de>"); +MODULE_DESCRIPTION("STMPEXXX touchscreen driver"); +MODULE_LICENSE("GPL"); |