Back to home page

OSCL-LXR
 
 

     

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  *  Philips UCB1400 touchscreen driver
0004  *
0005  *  Author: Nicolas Pitre
0006  *  Created:    September 25, 2006
0007  *  Copyright:  MontaVista Software, Inc.
0008  *
0009  * Spliting done by: Marek Vasut <marek.vasut@gmail.com>
0010  * If something doesn't work and it worked before spliting, e-mail me,
0011  * dont bother Nicolas please ;-)
0012  *
0013  * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
0014  * covering the UCB1100, UCB1200 and UCB1300..  Support for the UCB1400 has
0015  * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
0016  */
0017 
0018 #include <linux/module.h>
0019 #include <linux/delay.h>
0020 #include <linux/sched.h>
0021 #include <linux/wait.h>
0022 #include <linux/input.h>
0023 #include <linux/device.h>
0024 #include <linux/interrupt.h>
0025 #include <linux/ucb1400.h>
0026 
0027 #define UCB1400_TS_POLL_PERIOD  10 /* ms */
0028 
0029 static bool adcsync;
0030 static int ts_delay = 55; /* us */
0031 static int ts_delay_pressure;   /* us */
0032 
0033 /* Switch to interrupt mode. */
0034 static void ucb1400_ts_mode_int(struct ucb1400_ts *ucb)
0035 {
0036     ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
0037             UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
0038             UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
0039             UCB_TS_CR_MODE_INT);
0040 }
0041 
0042 /*
0043  * Switch to pressure mode, and read pressure.  We don't need to wait
0044  * here, since both plates are being driven.
0045  */
0046 static unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
0047 {
0048     ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
0049             UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
0050             UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
0051             UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
0052 
0053     udelay(ts_delay_pressure);
0054 
0055     return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
0056 }
0057 
0058 /*
0059  * Switch to X position mode and measure Y plate.  We switch the plate
0060  * configuration in pressure mode, then switch to position mode.  This
0061  * gives a faster response time.  Even so, we need to wait about 55us
0062  * for things to stabilise.
0063  */
0064 static unsigned int ucb1400_ts_read_xpos(struct ucb1400_ts *ucb)
0065 {
0066     ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
0067             UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
0068             UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
0069     ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
0070             UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
0071             UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
0072     ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
0073             UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
0074             UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
0075 
0076     udelay(ts_delay);
0077 
0078     return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
0079 }
0080 
0081 /*
0082  * Switch to Y position mode and measure X plate.  We switch the plate
0083  * configuration in pressure mode, then switch to position mode.  This
0084  * gives a faster response time.  Even so, we need to wait about 55us
0085  * for things to stabilise.
0086  */
0087 static int ucb1400_ts_read_ypos(struct ucb1400_ts *ucb)
0088 {
0089     ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
0090             UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
0091             UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
0092     ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
0093             UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
0094             UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
0095     ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
0096             UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
0097             UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
0098 
0099     udelay(ts_delay);
0100 
0101     return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPX, adcsync);
0102 }
0103 
0104 /*
0105  * Switch to X plate resistance mode.  Set MX to ground, PX to
0106  * supply.  Measure current.
0107  */
0108 static unsigned int ucb1400_ts_read_xres(struct ucb1400_ts *ucb)
0109 {
0110     ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
0111             UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
0112             UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
0113     return ucb1400_adc_read(ucb->ac97, 0, adcsync);
0114 }
0115 
0116 /*
0117  * Switch to Y plate resistance mode.  Set MY to ground, PY to
0118  * supply.  Measure current.
0119  */
0120 static unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
0121 {
0122     ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
0123             UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
0124             UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
0125     return ucb1400_adc_read(ucb->ac97, 0, adcsync);
0126 }
0127 
0128 static int ucb1400_ts_pen_up(struct ucb1400_ts *ucb)
0129 {
0130     unsigned short val = ucb1400_reg_read(ucb->ac97, UCB_TS_CR);
0131 
0132     return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
0133 }
0134 
0135 static void ucb1400_ts_irq_enable(struct ucb1400_ts *ucb)
0136 {
0137     ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
0138     ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
0139     ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_TSPX);
0140 }
0141 
0142 static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)
0143 {
0144     ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
0145 }
0146 
0147 static void ucb1400_ts_report_event(struct input_dev *idev, u16 pressure, u16 x, u16 y)
0148 {
0149     input_report_abs(idev, ABS_X, x);
0150     input_report_abs(idev, ABS_Y, y);
0151     input_report_abs(idev, ABS_PRESSURE, pressure);
0152     input_report_key(idev, BTN_TOUCH, 1);
0153     input_sync(idev);
0154 }
0155 
0156 static void ucb1400_ts_event_release(struct input_dev *idev)
0157 {
0158     input_report_abs(idev, ABS_PRESSURE, 0);
0159     input_report_key(idev, BTN_TOUCH, 0);
0160     input_sync(idev);
0161 }
0162 
0163 static void ucb1400_clear_pending_irq(struct ucb1400_ts *ucb)
0164 {
0165     unsigned int isr;
0166 
0167     isr = ucb1400_reg_read(ucb->ac97, UCB_IE_STATUS);
0168     ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, isr);
0169     ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
0170 
0171     if (isr & UCB_IE_TSPX)
0172         ucb1400_ts_irq_disable(ucb);
0173     else
0174         dev_dbg(&ucb->ts_idev->dev,
0175             "ucb1400: unexpected IE_STATUS = %#x\n", isr);
0176 }
0177 
0178 /*
0179  * A restriction with interrupts exists when using the ucb1400, as
0180  * the codec read/write routines may sleep while waiting for codec
0181  * access completion and uses semaphores for access control to the
0182  * AC97 bus. Therefore the driver is forced to use threaded interrupt
0183  * handler.
0184  */
0185 static irqreturn_t ucb1400_irq(int irqnr, void *devid)
0186 {
0187     struct ucb1400_ts *ucb = devid;
0188     unsigned int x, y, p;
0189 
0190     if (unlikely(irqnr != ucb->irq))
0191         return IRQ_NONE;
0192 
0193     ucb1400_clear_pending_irq(ucb);
0194 
0195     /* Start with a small delay before checking pendown state */
0196     msleep(UCB1400_TS_POLL_PERIOD);
0197 
0198     while (!ucb->stopped && !ucb1400_ts_pen_up(ucb)) {
0199         ucb1400_adc_enable(ucb->ac97);
0200         x = ucb1400_ts_read_xpos(ucb);
0201         y = ucb1400_ts_read_ypos(ucb);
0202         p = ucb1400_ts_read_pressure(ucb);
0203         ucb1400_adc_disable(ucb->ac97);
0204 
0205         ucb1400_ts_report_event(ucb->ts_idev, p, x, y);
0206 
0207         wait_event_timeout(ucb->ts_wait, ucb->stopped,
0208                    msecs_to_jiffies(UCB1400_TS_POLL_PERIOD));
0209     }
0210 
0211     ucb1400_ts_event_release(ucb->ts_idev);
0212 
0213     if (!ucb->stopped) {
0214         /* Switch back to interrupt mode. */
0215         ucb1400_ts_mode_int(ucb);
0216         ucb1400_ts_irq_enable(ucb);
0217     }
0218 
0219     return IRQ_HANDLED;
0220 }
0221 
0222 static void ucb1400_ts_stop(struct ucb1400_ts *ucb)
0223 {
0224     /* Signal IRQ thread to stop polling and disable the handler. */
0225     ucb->stopped = true;
0226     mb();
0227     wake_up(&ucb->ts_wait);
0228     disable_irq(ucb->irq);
0229 
0230     ucb1400_ts_irq_disable(ucb);
0231     ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
0232 }
0233 
0234 /* Must be called with ts->lock held */
0235 static void ucb1400_ts_start(struct ucb1400_ts *ucb)
0236 {
0237     /* Tell IRQ thread that it may poll the device. */
0238     ucb->stopped = false;
0239     mb();
0240 
0241     ucb1400_ts_mode_int(ucb);
0242     ucb1400_ts_irq_enable(ucb);
0243 
0244     enable_irq(ucb->irq);
0245 }
0246 
0247 static int ucb1400_ts_open(struct input_dev *idev)
0248 {
0249     struct ucb1400_ts *ucb = input_get_drvdata(idev);
0250 
0251     ucb1400_ts_start(ucb);
0252 
0253     return 0;
0254 }
0255 
0256 static void ucb1400_ts_close(struct input_dev *idev)
0257 {
0258     struct ucb1400_ts *ucb = input_get_drvdata(idev);
0259 
0260     ucb1400_ts_stop(ucb);
0261 }
0262 
0263 #ifndef NO_IRQ
0264 #define NO_IRQ  0
0265 #endif
0266 
0267 /*
0268  * Try to probe our interrupt, rather than relying on lots of
0269  * hard-coded machine dependencies.
0270  */
0271 static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb,
0272                        struct platform_device *pdev)
0273 {
0274     unsigned long mask, timeout;
0275 
0276     mask = probe_irq_on();
0277 
0278     /* Enable the ADC interrupt. */
0279     ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, UCB_IE_ADC);
0280     ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_ADC);
0281     ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
0282     ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
0283 
0284     /* Cause an ADC interrupt. */
0285     ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA);
0286     ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
0287 
0288     /* Wait for the conversion to complete. */
0289     timeout = jiffies + HZ/2;
0290     while (!(ucb1400_reg_read(ucb->ac97, UCB_ADC_DATA) &
0291                         UCB_ADC_DAT_VALID)) {
0292         cpu_relax();
0293         if (time_after(jiffies, timeout)) {
0294             dev_err(&pdev->dev, "timed out in IRQ probe\n");
0295             probe_irq_off(mask);
0296             return -ENODEV;
0297         }
0298     }
0299     ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, 0);
0300 
0301     /* Disable and clear interrupt. */
0302     ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, 0);
0303     ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
0304     ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
0305     ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
0306 
0307     /* Read triggered interrupt. */
0308     ucb->irq = probe_irq_off(mask);
0309     if (ucb->irq < 0 || ucb->irq == NO_IRQ)
0310         return -ENODEV;
0311 
0312     return 0;
0313 }
0314 
0315 static int ucb1400_ts_probe(struct platform_device *pdev)
0316 {
0317     struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
0318     int error, x_res, y_res;
0319     u16 fcsr;
0320 
0321     ucb->ts_idev = input_allocate_device();
0322     if (!ucb->ts_idev) {
0323         error = -ENOMEM;
0324         goto err;
0325     }
0326 
0327     /* Only in case the IRQ line wasn't supplied, try detecting it */
0328     if (ucb->irq < 0) {
0329         error = ucb1400_ts_detect_irq(ucb, pdev);
0330         if (error) {
0331             dev_err(&pdev->dev, "IRQ probe failed\n");
0332             goto err_free_devs;
0333         }
0334     }
0335     dev_dbg(&pdev->dev, "found IRQ %d\n", ucb->irq);
0336 
0337     init_waitqueue_head(&ucb->ts_wait);
0338 
0339     input_set_drvdata(ucb->ts_idev, ucb);
0340 
0341     ucb->ts_idev->dev.parent    = &pdev->dev;
0342     ucb->ts_idev->name      = "UCB1400 touchscreen interface";
0343     ucb->ts_idev->id.vendor     = ucb1400_reg_read(ucb->ac97,
0344                         AC97_VENDOR_ID1);
0345     ucb->ts_idev->id.product    = ucb->id;
0346     ucb->ts_idev->open      = ucb1400_ts_open;
0347     ucb->ts_idev->close     = ucb1400_ts_close;
0348     ucb->ts_idev->evbit[0]      = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
0349     ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
0350 
0351     /*
0352      * Enable ADC filter to prevent horrible jitter on Colibri.
0353      * This also further reduces jitter on boards where ADCSYNC
0354      * pin is connected.
0355      */
0356     fcsr = ucb1400_reg_read(ucb->ac97, UCB_FCSR);
0357     ucb1400_reg_write(ucb->ac97, UCB_FCSR, fcsr | UCB_FCSR_AVE);
0358 
0359     ucb1400_adc_enable(ucb->ac97);
0360     x_res = ucb1400_ts_read_xres(ucb);
0361     y_res = ucb1400_ts_read_yres(ucb);
0362     ucb1400_adc_disable(ucb->ac97);
0363     dev_dbg(&pdev->dev, "x/y = %d/%d\n", x_res, y_res);
0364 
0365     input_set_abs_params(ucb->ts_idev, ABS_X, 0, x_res, 0, 0);
0366     input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);
0367     input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);
0368 
0369     ucb1400_ts_stop(ucb);
0370 
0371     error = request_threaded_irq(ucb->irq, NULL, ucb1400_irq,
0372                      IRQF_TRIGGER_RISING | IRQF_ONESHOT,
0373                      "UCB1400", ucb);
0374     if (error) {
0375         dev_err(&pdev->dev,
0376             "unable to grab irq%d: %d\n", ucb->irq, error);
0377         goto err_free_devs;
0378     }
0379 
0380     error = input_register_device(ucb->ts_idev);
0381     if (error)
0382         goto err_free_irq;
0383 
0384     return 0;
0385 
0386 err_free_irq:
0387     free_irq(ucb->irq, ucb);
0388 err_free_devs:
0389     input_free_device(ucb->ts_idev);
0390 err:
0391     return error;
0392 }
0393 
0394 static int ucb1400_ts_remove(struct platform_device *pdev)
0395 {
0396     struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
0397 
0398     free_irq(ucb->irq, ucb);
0399     input_unregister_device(ucb->ts_idev);
0400 
0401     return 0;
0402 }
0403 
0404 static int __maybe_unused ucb1400_ts_suspend(struct device *dev)
0405 {
0406     struct ucb1400_ts *ucb = dev_get_platdata(dev);
0407     struct input_dev *idev = ucb->ts_idev;
0408 
0409     mutex_lock(&idev->mutex);
0410 
0411     if (input_device_enabled(idev))
0412         ucb1400_ts_stop(ucb);
0413 
0414     mutex_unlock(&idev->mutex);
0415     return 0;
0416 }
0417 
0418 static int __maybe_unused ucb1400_ts_resume(struct device *dev)
0419 {
0420     struct ucb1400_ts *ucb = dev_get_platdata(dev);
0421     struct input_dev *idev = ucb->ts_idev;
0422 
0423     mutex_lock(&idev->mutex);
0424 
0425     if (input_device_enabled(idev))
0426         ucb1400_ts_start(ucb);
0427 
0428     mutex_unlock(&idev->mutex);
0429     return 0;
0430 }
0431 
0432 static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,
0433              ucb1400_ts_suspend, ucb1400_ts_resume);
0434 
0435 static struct platform_driver ucb1400_ts_driver = {
0436     .probe  = ucb1400_ts_probe,
0437     .remove = ucb1400_ts_remove,
0438     .driver = {
0439         .name   = "ucb1400_ts",
0440         .pm = &ucb1400_ts_pm_ops,
0441     },
0442 };
0443 module_platform_driver(ucb1400_ts_driver);
0444 
0445 module_param(adcsync, bool, 0444);
0446 MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
0447 
0448 module_param(ts_delay, int, 0444);
0449 MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
0450                 " position read. Default = 55us.");
0451 
0452 module_param(ts_delay_pressure, int, 0444);
0453 MODULE_PARM_DESC(ts_delay_pressure,
0454         "delay between panel setup and pressure read."
0455         "  Default = 0us.");
0456 
0457 MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
0458 MODULE_LICENSE("GPL");
[ Source navigation ] [ Diff markup ] [ Identifier search ] [ general search ]

This page was automatically generated by the 2.1.0 LXR engine.

The LXR team
Valid CSS 2.1! Valid HTML 4.01!