Input: add LPC32xx touchscreen controller driver
authorKevin Wells <wellsk40@gmail.com>
Sun, 29 Aug 2010 05:45:22 +0000 (22:45 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Sun, 29 Aug 2010 05:46:18 +0000 (22:46 -0700)
This patch set introduces support for the LPC32xx touchscreen
controller driver. The LPC32xx touchscreen controller supports
automated event detection and X/Y data conversion for resistive
touchscreens.

Signed-off-by: Kevin Wells <wellsk40@gmail.com>
Signed-off-by: Durgesh Pattamatta <durgesh.pattamatta@nxp.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
drivers/input/touchscreen/Kconfig
drivers/input/touchscreen/Makefile
drivers/input/touchscreen/lpc32xx_ts.c [new file with mode: 0644]

index 0069d97..400c99d 100644 (file)
@@ -214,6 +214,16 @@ config TOUCHSCREEN_WACOM_W8001
          To compile this driver as a module, choose M here: the
          module will be called wacom_w8001.
 
+config TOUCHSCREEN_LPC32XX
+       tristate "LPC32XX touchscreen controller"
+       depends on ARCH_LPC32XX
+       help
+         Say Y here if you have a LPC32XX device and want
+         to support the built-in touchscreen.
+
+         To compile this driver as a module, choose M here: the
+         module will be called lpc32xx_ts.
+
 config TOUCHSCREEN_MCS5000
        tristate "MELFAS MCS-5000 touchscreen"
        depends on I2C
index 28217e1..22e2d59 100644 (file)
@@ -23,6 +23,7 @@ obj-$(CONFIG_TOUCHSCREEN_EETI)                += eeti_ts.o
 obj-$(CONFIG_TOUCHSCREEN_ELO)          += elo.o
 obj-$(CONFIG_TOUCHSCREEN_FUJITSU)      += fujitsu_ts.o
 obj-$(CONFIG_TOUCHSCREEN_INEXIO)       += inexio.o
+obj-$(CONFIG_TOUCHSCREEN_LPC32XX)      += lpc32xx_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MC13783)      += mc13783_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MCS5000)      += mcs5000_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MIGOR)                += migor_ts.o
diff --git a/drivers/input/touchscreen/lpc32xx_ts.c b/drivers/input/touchscreen/lpc32xx_ts.c
new file mode 100644 (file)
index 0000000..dcf803f
--- /dev/null
@@ -0,0 +1,411 @@
+/*
+ * LPC32xx built-in touchscreen driver
+ *
+ * Copyright (C) 2010 NXP Semiconductors
+ *
+ * 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.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+/*
+ * Touchscreen controller register offsets
+ */
+#define LPC32XX_TSC_STAT                       0x00
+#define LPC32XX_TSC_SEL                                0x04
+#define LPC32XX_TSC_CON                                0x08
+#define LPC32XX_TSC_FIFO                       0x0C
+#define LPC32XX_TSC_DTR                                0x10
+#define LPC32XX_TSC_RTR                                0x14
+#define LPC32XX_TSC_UTR                                0x18
+#define LPC32XX_TSC_TTR                                0x1C
+#define LPC32XX_TSC_DXP                                0x20
+#define LPC32XX_TSC_MIN_X                      0x24
+#define LPC32XX_TSC_MAX_X                      0x28
+#define LPC32XX_TSC_MIN_Y                      0x2C
+#define LPC32XX_TSC_MAX_Y                      0x30
+#define LPC32XX_TSC_AUX_UTR                    0x34
+#define LPC32XX_TSC_AUX_MIN                    0x38
+#define LPC32XX_TSC_AUX_MAX                    0x3C
+
+#define LPC32XX_TSC_STAT_FIFO_OVRRN            (1 << 8)
+#define LPC32XX_TSC_STAT_FIFO_EMPTY            (1 << 7)
+
+#define LPC32XX_TSC_SEL_DEFVAL                 0x0284
+
+#define LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4       (0x1 << 11)
+#define LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(s)    ((10 - (s)) << 7)
+#define LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(s)    ((10 - (s)) << 4)
+#define LPC32XX_TSC_ADCCON_POWER_UP            (1 << 2)
+#define LPC32XX_TSC_ADCCON_AUTO_EN             (1 << 0)
+
+#define LPC32XX_TSC_FIFO_TS_P_LEVEL            (1 << 31)
+#define LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(x)    (((x) & 0x03FF0000) >> 16)
+#define LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(y)    ((y) & 0x000003FF)
+
+#define LPC32XX_TSC_ADCDAT_VALUE_MASK          0x000003FF
+
+#define LPC32XX_TSC_MIN_XY_VAL                 0x0
+#define LPC32XX_TSC_MAX_XY_VAL                 0x3FF
+
+#define MOD_NAME "ts-lpc32xx"
+
+#define tsc_readl(dev, reg) \
+       __raw_readl((dev)->tsc_base + (reg))
+#define tsc_writel(dev, reg, val) \
+       __raw_writel((val), (dev)->tsc_base + (reg))
+
+struct lpc32xx_tsc {
+       struct input_dev *dev;
+       void __iomem *tsc_base;
+       int irq;
+       struct clk *clk;
+};
+
+static void lpc32xx_fifo_clear(struct lpc32xx_tsc *tsc)
+{
+       while (!(tsc_readl(tsc, LPC32XX_TSC_STAT) &
+                       LPC32XX_TSC_STAT_FIFO_EMPTY))
+               tsc_readl(tsc, LPC32XX_TSC_FIFO);
+}
+
+static irqreturn_t lpc32xx_ts_interrupt(int irq, void *dev_id)
+{
+       u32 tmp, rv[4], xs[4], ys[4];
+       int idx;
+       struct lpc32xx_tsc *tsc = dev_id;
+       struct input_dev *input = tsc->dev;
+
+       tmp = tsc_readl(tsc, LPC32XX_TSC_STAT);
+
+       if (tmp & LPC32XX_TSC_STAT_FIFO_OVRRN) {
+               /* FIFO overflow - throw away samples */
+               lpc32xx_fifo_clear(tsc);
+               return IRQ_HANDLED;
+       }
+
+       /*
+        * Gather and normalize 4 samples. Pen-up events may have less
+        * than 4 samples, but its ok to pop 4 and let the last sample
+        * pen status check drop the samples.
+        */
+       idx = 0;
+       while (idx < 4 &&
+              !(tsc_readl(tsc, LPC32XX_TSC_STAT) &
+                       LPC32XX_TSC_STAT_FIFO_EMPTY)) {
+               tmp = tsc_readl(tsc, LPC32XX_TSC_FIFO);
+               xs[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
+                       LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(tmp);
+               ys[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
+                       LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(tmp);
+               rv[idx] = tmp;
+               idx++;
+       }
+
+       /* Data is only valid if pen is still down in last sample */
+       if (!(rv[3] & LPC32XX_TSC_FIFO_TS_P_LEVEL) && idx == 4) {
+               /* Use average of 2nd and 3rd sample for position */
+               input_report_abs(input, ABS_X, (xs[1] + xs[2]) / 2);
+               input_report_abs(input, ABS_Y, (ys[1] + ys[2]) / 2);
+               input_report_key(input, BTN_TOUCH, 1);
+       } else {
+               input_report_key(input, BTN_TOUCH, 0);
+       }
+
+       input_sync(input);
+
+       return IRQ_HANDLED;
+}
+
+static void lpc32xx_stop_tsc(struct lpc32xx_tsc *tsc)
+{
+       /* Disable auto mode */
+       tsc_writel(tsc, LPC32XX_TSC_CON,
+                  tsc_readl(tsc, LPC32XX_TSC_CON) &
+                            ~LPC32XX_TSC_ADCCON_AUTO_EN);
+
+       clk_disable(tsc->clk);
+}
+
+static void lpc32xx_setup_tsc(struct lpc32xx_tsc *tsc)
+{
+       u32 tmp;
+
+       clk_enable(tsc->clk);
+
+       tmp = tsc_readl(tsc, LPC32XX_TSC_CON) & ~LPC32XX_TSC_ADCCON_POWER_UP;
+
+       /* Set the TSC FIFO depth to 4 samples @ 10-bits per sample (max) */
+       tmp = LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 |
+             LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(10) |
+             LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(10);
+       tsc_writel(tsc, LPC32XX_TSC_CON, tmp);
+
+       /* These values are all preset */
+       tsc_writel(tsc, LPC32XX_TSC_SEL, LPC32XX_TSC_SEL_DEFVAL);
+       tsc_writel(tsc, LPC32XX_TSC_MIN_X, LPC32XX_TSC_MIN_XY_VAL);
+       tsc_writel(tsc, LPC32XX_TSC_MAX_X, LPC32XX_TSC_MAX_XY_VAL);
+       tsc_writel(tsc, LPC32XX_TSC_MIN_Y, LPC32XX_TSC_MIN_XY_VAL);
+       tsc_writel(tsc, LPC32XX_TSC_MAX_Y, LPC32XX_TSC_MAX_XY_VAL);
+
+       /* Aux support is not used */
+       tsc_writel(tsc, LPC32XX_TSC_AUX_UTR, 0);
+       tsc_writel(tsc, LPC32XX_TSC_AUX_MIN, 0);
+       tsc_writel(tsc, LPC32XX_TSC_AUX_MAX, 0);
+
+       /*
+        * Set sample rate to about 240Hz per X/Y pair. A single measurement
+        * consists of 4 pairs which gives about a 60Hz sample rate based on
+        * a stable 32768Hz clock source. Values are in clocks.
+        * Rate is (32768 / (RTR + XCONV + RTR + YCONV + DXP + TTR + UTR) / 4
+        */
+       tsc_writel(tsc, LPC32XX_TSC_RTR, 0x2);
+       tsc_writel(tsc, LPC32XX_TSC_DTR, 0x2);
+       tsc_writel(tsc, LPC32XX_TSC_TTR, 0x10);
+       tsc_writel(tsc, LPC32XX_TSC_DXP, 0x4);
+       tsc_writel(tsc, LPC32XX_TSC_UTR, 88);
+
+       lpc32xx_fifo_clear(tsc);
+
+       /* Enable automatic ts event capture */
+       tsc_writel(tsc, LPC32XX_TSC_CON, tmp | LPC32XX_TSC_ADCCON_AUTO_EN);
+}
+
+static int lpc32xx_ts_open(struct input_dev *dev)
+{
+       struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
+
+       lpc32xx_setup_tsc(tsc);
+
+       return 0;
+}
+
+static void lpc32xx_ts_close(struct input_dev *dev)
+{
+       struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
+
+       lpc32xx_stop_tsc(tsc);
+}
+
+static int __devinit lpc32xx_ts_probe(struct platform_device *pdev)
+{
+       struct lpc32xx_tsc *tsc;
+       struct input_dev *input;
+       struct resource *res;
+       resource_size_t size;
+       int irq;
+       int error;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res) {
+               dev_err(&pdev->dev, "Can't get memory resource\n");
+               return -ENOENT;
+       }
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               dev_err(&pdev->dev, "Can't get interrupt resource\n");
+               return irq;
+       }
+
+       tsc = kzalloc(sizeof(*tsc), GFP_KERNEL);
+       input = input_allocate_device();
+       if (!tsc || !input) {
+               dev_err(&pdev->dev, "failed allocating memory\n");
+               error = -ENOMEM;
+               goto err_free_mem;
+       }
+
+       tsc->dev = input;
+       tsc->irq = irq;
+
+       size = resource_size(res);
+
+       if (!request_mem_region(res->start, size, pdev->name)) {
+               dev_err(&pdev->dev, "TSC registers are not free\n");
+               error = -EBUSY;
+               goto err_free_mem;
+       }
+
+       tsc->tsc_base = ioremap(res->start, size);
+       if (!tsc->tsc_base) {
+               dev_err(&pdev->dev, "Can't map memory\n");
+               error = -ENOMEM;
+               goto err_release_mem;
+       }
+
+       tsc->clk = clk_get(&pdev->dev, NULL);
+       if (IS_ERR(tsc->clk)) {
+               dev_err(&pdev->dev, "failed getting clock\n");
+               error = PTR_ERR(tsc->clk);
+               goto err_unmap;
+       }
+
+       input->name = MOD_NAME;
+       input->phys = "lpc32xx/input0";
+       input->id.bustype = BUS_HOST;
+       input->id.vendor = 0x0001;
+       input->id.product = 0x0002;
+       input->id.version = 0x0100;
+       input->dev.parent = &pdev->dev;
+       input->open = lpc32xx_ts_open;
+       input->close = lpc32xx_ts_close;
+
+       input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+       input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+       input_set_abs_params(input, ABS_X, LPC32XX_TSC_MIN_XY_VAL,
+                            LPC32XX_TSC_MAX_XY_VAL, 0, 0);
+       input_set_abs_params(input, ABS_Y, LPC32XX_TSC_MIN_XY_VAL,
+                            LPC32XX_TSC_MAX_XY_VAL, 0, 0);
+
+       input_set_drvdata(input, tsc);
+
+       error = request_irq(tsc->irq, lpc32xx_ts_interrupt,
+                           IRQF_DISABLED, pdev->name, tsc);
+       if (error) {
+               dev_err(&pdev->dev, "failed requesting interrupt\n");
+               goto err_put_clock;
+       }
+
+       error = input_register_device(input);
+       if (error) {
+               dev_err(&pdev->dev, "failed registering input device\n");
+               goto err_free_irq;
+       }
+
+       platform_set_drvdata(pdev, tsc);
+       device_init_wakeup(&pdev->dev, 1);
+
+       return 0;
+
+err_free_irq:
+       free_irq(tsc->irq, tsc);
+err_put_clock:
+       clk_put(tsc->clk);
+err_unmap:
+       iounmap(tsc->tsc_base);
+err_release_mem:
+       release_mem_region(res->start, size);
+err_free_mem:
+       input_free_device(input);
+       kfree(tsc);
+
+       return error;
+}
+
+static int __devexit lpc32xx_ts_remove(struct platform_device *pdev)
+{
+       struct lpc32xx_tsc *tsc = platform_get_drvdata(pdev);
+       struct resource *res;
+
+       device_init_wakeup(&pdev->dev, 0);
+       free_irq(tsc->irq, tsc);
+
+       input_unregister_device(tsc->dev);
+
+       clk_put(tsc->clk);
+
+       iounmap(tsc->tsc_base);
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       release_mem_region(res->start, resource_size(res));
+
+       kfree(tsc);
+
+       return 0;
+}
+
+#ifdef CONFIG_PM
+static int lpc32xx_ts_suspend(struct device *dev)
+{
+       struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
+       struct input_dev *input = tsc->dev;
+
+       /*
+        * Suspend and resume can be called when the device hasn't been
+        * enabled. If there are no users that have the device open, then
+        * avoid calling the TSC stop and start functions as the TSC
+        * isn't yet clocked.
+        */
+       mutex_lock(&input->mutex);
+
+       if (input->users) {
+               if (device_may_wakeup(dev))
+                       enable_irq_wake(tsc->irq);
+               else
+                       lpc32xx_stop_tsc(tsc);
+       }
+
+       mutex_unlock(&input->mutex);
+
+       return 0;
+}
+
+static int lpc32xx_ts_resume(struct device *dev)
+{
+       struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
+       struct input_dev *input = tsc->dev;
+
+       mutex_lock(&input->mutex);
+
+       if (input->users) {
+               if (device_may_wakeup(dev))
+                       disable_irq_wake(tsc->irq);
+               else
+                       lpc32xx_setup_tsc(tsc);
+       }
+
+       mutex_unlock(&input->mutex);
+
+       return 0;
+}
+
+static const struct dev_pm_ops lpc32xx_ts_pm_ops = {
+       .suspend        = lpc32xx_ts_suspend,
+       .resume         = lpc32xx_ts_resume,
+};
+#define LPC32XX_TS_PM_OPS (&lpc32xx_ts_pm_ops)
+#else
+#define LPC32XX_TS_PM_OPS NULL
+#endif
+
+static struct platform_driver lpc32xx_ts_driver = {
+       .probe          = lpc32xx_ts_probe,
+       .remove         = __devexit_p(lpc32xx_ts_remove),
+       .driver         = {
+               .name   = MOD_NAME,
+               .owner  = THIS_MODULE,
+               .pm     = LPC32XX_TS_PM_OPS,
+       },
+};
+
+static int __init lpc32xx_ts_init(void)
+{
+       return platform_driver_register(&lpc32xx_ts_driver);
+}
+module_init(lpc32xx_ts_init);
+
+static void __exit lpc32xx_ts_exit(void)
+{
+       platform_driver_unregister(&lpc32xx_ts_driver);
+}
+module_exit(lpc32xx_ts_exit);
+
+MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com");
+MODULE_DESCRIPTION("LPC32XX TSC Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lpc32xx_ts");