Input: add driver for Atmel integrated touchscreen controller

The AT91SAM9RL SoC integrates a Touchscreen Controller which
can trigger ADC conversion periodically.

Signed-off-by: Justin Waters <justin.waters@timesys.com>
Signed-off-by: Dan Liang <dan.liang@atmel.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

3 files changed, 345 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index e57366521572..6e60a97a234c 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -205,6 +205,18 @@ config TOUCHSCREEN_TOUCHWIN
           To compile this driver as a module, choose M here: the
           module will be called touchwin.
 
+config TOUCHSCREEN_ATMEL_TSADCC
+        tristate "Atmel Touchscreen Interface"
+        depends on ARCH_AT91SAM9RL
+        help
+          Say Y here if you have a 4-wire touchscreen connected to the
+          ADC Controller on your Atmel SoC (such as the AT91SAM9RL).
+
+          If unsure, say N.
+
+          To compile this driver as a module, choose M here: the
+          module will be called atmel_tsadcc.
+
 config TOUCHSCREEN_UCB1400
         tristate "Philips UCB1400 touchscreen"
         select AC97_BUS
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 39a804cd80f1..15cf29079489 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -7,6 +7,7 @@
 wm97xx-ts-y := wm97xx-core.o
 
 obj-$(CONFIG_TOUCHSCREEN_ADS7846)       += ads7846.o
+obj-$(CONFIG_TOUCHSCREEN_ATMEL_TSADCC)  += atmel_tsadcc.o
 obj-$(CONFIG_TOUCHSCREEN_BITSY)         += h3600_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_CORGI)         += corgi_ts.o
 obj-$(CONFIG_TOUCHSCREEN_GUNZE)         += gunze.o
diff --git a/drivers/input/touchscreen/atmel_tsadcc.c b/drivers/input/touchscreen/atmel_tsadcc.c
new file mode 100644
index 000000000000..eee126b19e8b
--- /dev/null
+++ b/drivers/input/touchscreen/atmel_tsadcc.c
@@ -0,0 +1,332 @@
+/*
+ *  Atmel Touch Screen Driver
+ *
+ *  Copyright (c) 2008 ATMEL
+ *  Copyright (c) 2008 Dan Liang
+ *  Copyright (c) 2008 TimeSys Corporation
+ *  Copyright (c) 2008 Justin Waters
+ *
+ *  Based on touchscreen code from Atmel Corporation.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+/* Register definitions based on AT91SAM9RL64 preliminary draft datasheet */
+
+#define ATMEL_TSADCC_CR         0x00    /* Control register */
+#define   ATMEL_TSADCC_SWRST    (1 << 0)        /* Software Reset*/
+#define   ATMEL_TSADCC_START    (1 << 1)        /* Start conversion */
+
+#define ATMEL_TSADCC_MR         0x04    /* Mode register */
+#define   ATMEL_TSADCC_TSAMOD   (3    <<  0)    /* ADC mode */
+#define     ATMEL_TSADCC_TSAMOD_ADC_ONLY_MODE   (0x0)   /* ADC Mode */
+#define     ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE    (0x1)   /* Touch Screen Only Mode */
+#define   ATMEL_TSADCC_LOWRES   (1    <<  4)    /* Resolution selection */
+#define   ATMEL_TSADCC_SLEEP    (1    <<  5)    /* Sleep mode */
+#define   ATMEL_TSADCC_PENDET   (1    <<  6)    /* Pen Detect selection */
+#define   ATMEL_TSADCC_PRESCAL  (0x3f <<  8)    /* Prescalar Rate Selection */
+#define   ATMEL_TSADCC_STARTUP  (0x7f << 16)    /* Start Up time */
+#define   ATMEL_TSADCC_SHTIM    (0xf  << 24)    /* Sample & Hold time */
+#define   ATMEL_TSADCC_PENDBC   (0xf  << 28)    /* Pen Detect debouncing time */
+
+#define ATMEL_TSADCC_TRGR       0x08    /* Trigger register */
+#define   ATMEL_TSADCC_TRGMOD   (7      <<  0)  /* Trigger mode */
+#define     ATMEL_TSADCC_TRGMOD_NONE            (0 << 0)
+#define     ATMEL_TSADCC_TRGMOD_EXT_RISING      (1 << 0)
+#define     ATMEL_TSADCC_TRGMOD_EXT_FALLING     (2 << 0)
+#define     ATMEL_TSADCC_TRGMOD_EXT_ANY         (3 << 0)
+#define     ATMEL_TSADCC_TRGMOD_PENDET          (4 << 0)
+#define     ATMEL_TSADCC_TRGMOD_PERIOD          (5 << 0)
+#define     ATMEL_TSADCC_TRGMOD_CONTINUOUS      (6 << 0)
+#define   ATMEL_TSADCC_TRGPER   (0xffff << 16)  /* Trigger period */
+
+#define ATMEL_TSADCC_TSR        0x0C    /* Touch Screen register */
+#define   ATMEL_TSADCC_TSFREQ   (0xf <<  0)     /* TS Frequency in Interleaved mode */
+#define   ATMEL_TSADCC_TSSHTIM  (0xf << 24)     /* Sample & Hold time */
+
+#define ATMEL_TSADCC_CHER       0x10    /* Channel Enable register */
+#define ATMEL_TSADCC_CHDR       0x14    /* Channel Disable register */
+#define ATMEL_TSADCC_CHSR       0x18    /* Channel Status register */
+#define   ATMEL_TSADCC_CH(n)    (1 << (n))      /* Channel number */
+
+#define ATMEL_TSADCC_SR         0x1C    /* Status register */
+#define   ATMEL_TSADCC_EOC(n)   (1 << ((n)+0))  /* End of conversion for channel N */
+#define   ATMEL_TSADCC_OVRE(n)  (1 << ((n)+8))  /* Overrun error for channel N */
+#define   ATMEL_TSADCC_DRDY     (1 << 16)       /* Data Ready */
+#define   ATMEL_TSADCC_GOVRE    (1 << 17)       /* General Overrun Error */
+#define   ATMEL_TSADCC_ENDRX    (1 << 18)       /* End of RX Buffer */
+#define   ATMEL_TSADCC_RXBUFF   (1 << 19)       /* TX Buffer full */
+#define   ATMEL_TSADCC_PENCNT   (1 << 20)       /* Pen contact */
+#define   ATMEL_TSADCC_NOCNT    (1 << 21)       /* No contact */
+
+#define ATMEL_TSADCC_LCDR       0x20    /* Last Converted Data register */
+#define   ATMEL_TSADCC_DATA     (0x3ff << 0)    /* Channel data */
+
+#define ATMEL_TSADCC_IER        0x24    /* Interrupt Enable register */
+#define ATMEL_TSADCC_IDR        0x28    /* Interrupt Disable register */
+#define ATMEL_TSADCC_IMR        0x2C    /* Interrupt Mask register */
+#define ATMEL_TSADCC_CDR0       0x30    /* Channel Data 0 */
+#define ATMEL_TSADCC_CDR1       0x34    /* Channel Data 1 */
+#define ATMEL_TSADCC_CDR2       0x38    /* Channel Data 2 */
+#define ATMEL_TSADCC_CDR3       0x3C    /* Channel Data 3 */
+#define ATMEL_TSADCC_CDR4       0x40    /* Channel Data 4 */
+#define ATMEL_TSADCC_CDR5       0x44    /* Channel Data 5 */
+
+#define ADC_CLOCK       1000000
+
+struct atmel_tsadcc {
+        struct input_dev        *input;
+        char                    phys[32];
+        struct clk              *clk;
+        int                     irq;
+};
+
+static void __iomem             *tsc_base;
+
+#define atmel_tsadcc_read(reg)          __raw_readl(tsc_base + (reg))
+#define atmel_tsadcc_write(reg, val)    __raw_writel((val), tsc_base + (reg))
+
+static irqreturn_t atmel_tsadcc_interrupt(int irq, void *dev)
+{
+        struct input_dev *input_dev = ((struct atmel_tsadcc *)dev)->input;
+
+        unsigned int absx;
+        unsigned int absy;
+        unsigned int status;
+        unsigned int reg;
+
+        status = atmel_tsadcc_read(ATMEL_TSADCC_SR);
+        status &= atmel_tsadcc_read(ATMEL_TSADCC_IMR);
+
+        if (status & ATMEL_TSADCC_NOCNT) {
+                /* Contact lost */
+                reg = atmel_tsadcc_read(ATMEL_TSADCC_MR) | ATMEL_TSADCC_PENDBC;
+
+                atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
+                atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
+                atmel_tsadcc_write(ATMEL_TSADCC_IDR,
+                                   ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
+                atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);
+
+                input_report_key(input_dev, BTN_TOUCH, 0);
+                input_sync(input_dev);
+
+        } else if (status & ATMEL_TSADCC_PENCNT) {
+                /* Pen detected */
+                reg = atmel_tsadcc_read(ATMEL_TSADCC_MR);
+                reg &= ~ATMEL_TSADCC_PENDBC;
+
+                atmel_tsadcc_write(ATMEL_TSADCC_IDR, ATMEL_TSADCC_PENCNT);
+                atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
+                atmel_tsadcc_write(ATMEL_TSADCC_IER,
+                                   ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
+                atmel_tsadcc_write(ATMEL_TSADCC_TRGR,
+                                   ATMEL_TSADCC_TRGMOD_PERIOD | (0x0FFF << 16));
+
+        } else if (status & ATMEL_TSADCC_EOC(3)) {
+                /* Conversion finished */
+
+                absx = atmel_tsadcc_read(ATMEL_TSADCC_CDR3) << 10;
+                absx /= atmel_tsadcc_read(ATMEL_TSADCC_CDR2);
+
+                absy = atmel_tsadcc_read(ATMEL_TSADCC_CDR1) << 10;
+                absy /= atmel_tsadcc_read(ATMEL_TSADCC_CDR0);
+
+                input_report_abs(input_dev, ABS_X, absx);
+                input_report_abs(input_dev, ABS_Y, absy);
+                input_report_key(input_dev, BTN_TOUCH, 1);
+                input_sync(input_dev);
+        }
+
+        return IRQ_HANDLED;
+}
+
+/*
+ * The functions for inserting/removing us as a module.
+ */
+
+static int __devinit atmel_tsadcc_probe(struct platform_device *pdev)
+{
+        struct atmel_tsadcc     *ts_dev;
+        struct input_dev        *input_dev;
+        struct resource         *res;
+        int             err = 0;
+        unsigned int    prsc;
+        unsigned int    reg;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res) {
+                dev_err(&pdev->dev, "no mmio resource defined.\n");
+                return -ENXIO;
+        }
+
+        /* Allocate memory for device */
+        ts_dev = kzalloc(sizeof(struct atmel_tsadcc), GFP_KERNEL);
+        if (!ts_dev) {
+                dev_err(&pdev->dev, "failed to allocate memory.\n");
+                return -ENOMEM;
+        }
+        platform_set_drvdata(pdev, ts_dev);
+
+        input_dev = input_allocate_device();
+        if (!input_dev) {
+                dev_err(&pdev->dev, "failed to allocate input device.\n");
+                err = -EBUSY;
+                goto err_free_mem;
+        }
+
+        ts_dev->irq = platform_get_irq(pdev, 0);
+        if (ts_dev->irq < 0) {
+                dev_err(&pdev->dev, "no irq ID is designated.\n");
+                err = -ENODEV;
+                goto err_free_dev;
+        }
+
+        if (!request_mem_region(res->start, res->end - res->start + 1,
+                                "atmel tsadcc regs")) {
+                dev_err(&pdev->dev, "resources is unavailable.\n");
+                err = -EBUSY;
+                goto err_free_dev;
+        }
+
+        tsc_base = ioremap(res->start, res->end - res->start + 1);
+        if (!tsc_base) {
+                dev_err(&pdev->dev, "failed to map registers.\n");
+                err = -ENOMEM;
+                goto err_release_mem;
+        }
+
+        err = request_irq(ts_dev->irq, atmel_tsadcc_interrupt, IRQF_DISABLED,
+                        pdev->dev.driver->name, ts_dev);
+        if (err) {
+                dev_err(&pdev->dev, "failed to allocate irq.\n");
+                goto err_unmap_regs;
+        }
+
+        ts_dev->clk = clk_get(&pdev->dev, "tsc_clk");
+        if (IS_ERR(ts_dev->clk)) {
+                dev_err(&pdev->dev, "failed to get ts_clk\n");
+                err = PTR_ERR(ts_dev->clk);
+                goto err_free_irq;
+        }
+
+        ts_dev->input = input_dev;
+
+        snprintf(ts_dev->phys, sizeof(ts_dev->phys),
+                 "%s/input0", pdev->dev.bus_id);
+
+        input_dev->name = "atmel touch screen controller";
+        input_dev->phys = ts_dev->phys;
+        input_dev->dev.parent = &pdev->dev;
+
+        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+        input_set_abs_params(input_dev, ABS_X, 0, 0x3FF, 0, 0);
+        input_set_abs_params(input_dev, ABS_Y, 0, 0x3FF, 0, 0);
+
+        /* clk_enable() always returns 0, no need to check it */
+        clk_enable(ts_dev->clk);
+
+        prsc = clk_get_rate(ts_dev->clk);
+        dev_info(&pdev->dev, "Master clock is set at: %d Hz\n", prsc);
+
+        prsc = prsc / ADC_CLOCK / 2 - 1;
+
+        reg = ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE          |
+                ((0x00 << 5) & ATMEL_TSADCC_SLEEP)      |       /* Normal Mode */
+                ((0x01 << 6) & ATMEL_TSADCC_PENDET)     |       /* Enable Pen Detect */
+                ((prsc << 8) & ATMEL_TSADCC_PRESCAL)    |       /* PRESCAL */
+                ((0x13 << 16) & ATMEL_TSADCC_STARTUP)   |       /* STARTUP */
+                ((0x0F << 28) & ATMEL_TSADCC_PENDBC);           /* PENDBC */
+
+        atmel_tsadcc_write(ATMEL_TSADCC_CR, ATMEL_TSADCC_SWRST);
+        atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
+        atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
+        atmel_tsadcc_write(ATMEL_TSADCC_TSR, (0x3 << 24) & ATMEL_TSADCC_TSSHTIM);
+
+        atmel_tsadcc_read(ATMEL_TSADCC_SR);
+        atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);
+
+        /* All went ok, so register to the input system */
+        err = input_register_device(input_dev);
+        if (err)
+                goto err_fail;
+
+        return 0;
+
+err_fail:
+        clk_disable(ts_dev->clk);
+        clk_put(ts_dev->clk);
+err_free_irq:
+        free_irq(ts_dev->irq, ts_dev);
+err_unmap_regs:
+        iounmap(tsc_base);
+err_release_mem:
+        release_mem_region(res->start, res->end - res->start + 1);
+err_free_dev:
+        input_free_device(ts_dev->input);
+err_free_mem:
+        kfree(ts_dev);
+        return err;
+}
+
+static int __devexit atmel_tsadcc_remove(struct platform_device *pdev)
+{
+        struct atmel_tsadcc *ts_dev = dev_get_drvdata(&pdev->dev);
+        struct resource *res;
+
+        free_irq(ts_dev->irq, ts_dev);
+
+        input_unregister_device(ts_dev->input);
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        iounmap(tsc_base);
+        release_mem_region(res->start, res->end - res->start + 1);
+
+        clk_disable(ts_dev->clk);
+        clk_put(ts_dev->clk);
+
+        kfree(ts_dev);
+
+        return 0;
+}
+
+static struct platform_driver atmel_tsadcc_driver = {
+        .probe          = atmel_tsadcc_probe,
+        .remove         = __devexit_p(atmel_tsadcc_remove),
+        .driver         = {
+                .name   = "atmel_tsadcc",
+        },
+};
+
+static int __init atmel_tsadcc_init(void)
+{
+        return platform_driver_register(&atmel_tsadcc_driver);
+}
+
+static void __exit atmel_tsadcc_exit(void)
+{
+        platform_driver_unregister(&atmel_tsadcc_driver);
+}
+
+module_init(atmel_tsadcc_init);
+module_exit(atmel_tsadcc_exit);
+
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Atmel TouchScreen Driver");
+MODULE_AUTHOR("Dan Liang <dan.liang@atmel.com>");
+