Input: Add Synaptics NavPoint (PXA27x SSP/SPI) driver

This driver adds support for the Synaptics NavPoint touchpad connected
to a PXA27x SSP port in SPI slave mode. The device emulates a mouse;
a tap or tap-and-a-half drag gesture emulates the left mouse button.
For example, use the xf86-input-evdev driver for an X pointing device.

Signed-off-by: Paul Parsons <lost.distance@yahoo.com>
Tested-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

3 files changed, 382 insertions, 0 deletions

diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index 9b8db821d5f0..cd6268cf7cd5 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -339,4 +339,16 @@ config MOUSE_SYNAPTICS_USB
           To compile this driver as a module, choose M here: the
           module will be called synaptics_usb.
 
+config MOUSE_NAVPOINT_PXA27x
+        tristate "Synaptics NavPoint (PXA27x SSP/SPI)"
+        depends on PXA27x && PXA_SSP
+        help
+          This driver adds support for the Synaptics NavPoint touchpad connected
+          to a PXA27x SSP port in SPI slave mode. The device emulates a mouse;
+          a tap or tap-and-a-half drag gesture emulates the left mouse button.
+          For example, use the xf86-input-evdev driver for an X pointing device.
+
+          To compile this driver as a module, choose M here: the
+          module will be called navpoint.
+
 endif
diff --git a/drivers/input/mouse/Makefile b/drivers/input/mouse/Makefile
index 4718effeb8d9..46ba7556fd4f 100644
--- a/drivers/input/mouse/Makefile
+++ b/drivers/input/mouse/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_MOUSE_GPIO)		+= gpio_mouse.o
 obj-$(CONFIG_MOUSE_INPORT)              += inport.o
 obj-$(CONFIG_MOUSE_LOGIBM)              += logibm.o
 obj-$(CONFIG_MOUSE_MAPLE)               += maplemouse.o
+obj-$(CONFIG_MOUSE_NAVPOINT_PXA27x)     += navpoint.o
 obj-$(CONFIG_MOUSE_PC110PAD)            += pc110pad.o
 obj-$(CONFIG_MOUSE_PS2)                 += psmouse.o
 obj-$(CONFIG_MOUSE_PXA930_TRKBALL)      += pxa930_trkball.o
diff --git a/drivers/input/mouse/navpoint.c b/drivers/input/mouse/navpoint.c
new file mode 100644
index 000000000000..c29ae7654d5e
--- /dev/null
+++ b/drivers/input/mouse/navpoint.c
@@ -0,0 +1,369 @@
+/*
+ * Synaptics NavPoint (PXA27x SSP/SPI) driver.
+ *
+ * Copyright (C) 2012 Paul Parsons <lost.distance@yahoo.com>
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/input.h>
+#include <linux/input/navpoint.h>
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/pxa2xx_ssp.h>
+#include <linux/slab.h>
+
+/*
+ * Synaptics Modular Embedded Protocol: Module Packet Format.
+ * Module header byte 2:0 = Length (# bytes that follow)
+ * Module header byte 4:3 = Control
+ * Module header byte 7:5 = Module Address
+ */
+#define HEADER_LENGTH(byte)     ((byte) & 0x07)
+#define HEADER_CONTROL(byte)    (((byte) >> 3) & 0x03)
+#define HEADER_ADDRESS(byte)    ((byte) >> 5)
+
+struct navpoint {
+        struct ssp_device       *ssp;
+        struct input_dev        *input;
+        struct device           *dev;
+        int                     gpio;
+        int                     index;
+        u8                      data[1 + HEADER_LENGTH(0xff)];
+};
+
+/*
+ * Initialization values for SSCR0_x, SSCR1_x, SSSR_x.
+ */
+static const u32 sscr0 = 0
+        | SSCR0_TUM             /* TIM = 1; No TUR interrupts */
+        | SSCR0_RIM             /* RIM = 1; No ROR interrupts */
+        | SSCR0_SSE             /* SSE = 1; SSP enabled */
+        | SSCR0_Motorola        /* FRF = 0; Motorola SPI */
+        | SSCR0_DataSize(16)    /* DSS = 15; Data size = 16-bit */
+        ;
+static const u32 sscr1 = 0
+        | SSCR1_SCFR            /* SCFR = 1; SSPSCLK only during transfers */
+        | SSCR1_SCLKDIR         /* SCLKDIR = 1; Slave mode */
+        | SSCR1_SFRMDIR         /* SFRMDIR = 1; Slave mode */
+        | SSCR1_RWOT            /* RWOT = 1; Receive without transmit mode */
+        | SSCR1_RxTresh(1)      /* RFT = 0; Receive FIFO threshold = 1 */
+        | SSCR1_SPH             /* SPH = 1; SSPSCLK inactive 0.5 + 1 cycles */
+        | SSCR1_RIE             /* RIE = 1; Receive FIFO interrupt enabled */
+        ;
+static const u32 sssr = 0
+        | SSSR_BCE              /* BCE = 1; Clear BCE */
+        | SSSR_TUR              /* TUR = 1; Clear TUR */
+        | SSSR_EOC              /* EOC = 1; Clear EOC */
+        | SSSR_TINT             /* TINT = 1; Clear TINT */
+        | SSSR_PINT             /* PINT = 1; Clear PINT */
+        | SSSR_ROR              /* ROR = 1; Clear ROR */
+        ;
+
+/*
+ * MEP Query $22: Touchpad Coordinate Range Query is not supported by
+ * the NavPoint module, so sampled values provide the default limits.
+ */
+#define NAVPOINT_X_MIN          1278
+#define NAVPOINT_X_MAX          5340
+#define NAVPOINT_Y_MIN          1572
+#define NAVPOINT_Y_MAX          4396
+#define NAVPOINT_PRESSURE_MIN   0
+#define NAVPOINT_PRESSURE_MAX   255
+
+static void navpoint_packet(struct navpoint *navpoint)
+{
+        int finger;
+        int gesture;
+        int x, y, z;
+
+        switch (navpoint->data[0]) {
+        case 0xff:      /* Garbage (packet?) between reset and Hello packet */
+        case 0x00:      /* Module 0, NULL packet */
+                break;
+
+        case 0x0e:      /* Module 0, Absolute packet */
+                finger = (navpoint->data[1] & 0x01);
+                gesture = (navpoint->data[1] & 0x02);
+                x = ((navpoint->data[2] & 0x1f) << 8) | navpoint->data[3];
+                y = ((navpoint->data[4] & 0x1f) << 8) | navpoint->data[5];
+                z = navpoint->data[6];
+                input_report_key(navpoint->input, BTN_TOUCH, finger);
+                input_report_abs(navpoint->input, ABS_X, x);
+                input_report_abs(navpoint->input, ABS_Y, y);
+                input_report_abs(navpoint->input, ABS_PRESSURE, z);
+                input_report_key(navpoint->input, BTN_TOOL_FINGER, finger);
+                input_report_key(navpoint->input, BTN_LEFT, gesture);
+                input_sync(navpoint->input);
+                break;
+
+        case 0x19:      /* Module 0, Hello packet */
+                if ((navpoint->data[1] & 0xf0) == 0x10)
+                        break;
+                /* FALLTHROUGH */
+        default:
+                dev_warn(navpoint->dev,
+                         "spurious packet: data=0x%02x,0x%02x,...\n",
+                         navpoint->data[0], navpoint->data[1]);
+                break;
+        }
+}
+
+static irqreturn_t navpoint_irq(int irq, void *dev_id)
+{
+        struct navpoint *navpoint = dev_id;
+        struct ssp_device *ssp = navpoint->ssp;
+        irqreturn_t ret = IRQ_NONE;
+        u32 status;
+
+        status = pxa_ssp_read_reg(ssp, SSSR);
+        if (status & sssr) {
+                dev_warn(navpoint->dev,
+                         "unexpected interrupt: status=0x%08x\n", status);
+                pxa_ssp_write_reg(ssp, SSSR, (status & sssr));
+                ret = IRQ_HANDLED;
+        }
+
+        while (status & SSSR_RNE) {
+                u32 data;
+
+                data = pxa_ssp_read_reg(ssp, SSDR);
+                navpoint->data[navpoint->index + 0] = (data >> 8);
+                navpoint->data[navpoint->index + 1] = data;
+                navpoint->index += 2;
+                if (HEADER_LENGTH(navpoint->data[0]) < navpoint->index) {
+                        navpoint_packet(navpoint);
+                        navpoint->index = 0;
+                }
+                status = pxa_ssp_read_reg(ssp, SSSR);
+                ret = IRQ_HANDLED;
+        }
+
+        return ret;
+}
+
+static void navpoint_up(struct navpoint *navpoint)
+{
+        struct ssp_device *ssp = navpoint->ssp;
+        int timeout;
+
+        clk_prepare_enable(ssp->clk);
+
+        pxa_ssp_write_reg(ssp, SSCR1, sscr1);
+        pxa_ssp_write_reg(ssp, SSSR, sssr);
+        pxa_ssp_write_reg(ssp, SSTO, 0);
+        pxa_ssp_write_reg(ssp, SSCR0, sscr0);   /* SSCR0_SSE written last */
+
+        /* Wait until SSP port is ready for slave clock operations */
+        for (timeout = 100; timeout != 0; --timeout) {
+                if (!(pxa_ssp_read_reg(ssp, SSSR) & SSSR_CSS))
+                        break;
+                msleep(1);
+        }
+
+        if (timeout == 0)
+                dev_err(navpoint->dev,
+                        "timeout waiting for SSSR[CSS] to clear\n");
+
+        if (gpio_is_valid(navpoint->gpio))
+                gpio_set_value(navpoint->gpio, 1);
+}
+
+static void navpoint_down(struct navpoint *navpoint)
+{
+        struct ssp_device *ssp = navpoint->ssp;
+
+        if (gpio_is_valid(navpoint->gpio))
+                gpio_set_value(navpoint->gpio, 0);
+
+        pxa_ssp_write_reg(ssp, SSCR0, 0);
+
+        clk_disable_unprepare(ssp->clk);
+}
+
+static int navpoint_open(struct input_dev *input)
+{
+        struct navpoint *navpoint = input_get_drvdata(input);
+
+        navpoint_up(navpoint);
+
+        return 0;
+}
+
+static void navpoint_close(struct input_dev *input)
+{
+        struct navpoint *navpoint = input_get_drvdata(input);
+
+        navpoint_down(navpoint);
+}
+
+static int __devinit navpoint_probe(struct platform_device *pdev)
+{
+        const struct navpoint_platform_data *pdata =
+                                        dev_get_platdata(&pdev->dev);
+        struct ssp_device *ssp;
+        struct input_dev *input;
+        struct navpoint *navpoint;
+        int error;
+
+        if (!pdata) {
+                dev_err(&pdev->dev, "no platform data\n");
+                return -EINVAL;
+        }
+
+        if (gpio_is_valid(pdata->gpio)) {
+                error = gpio_request_one(pdata->gpio, GPIOF_OUT_INIT_LOW,
+                                         "SYNAPTICS_ON");
+                if (error)
+                        return error;
+        }
+
+        ssp = pxa_ssp_request(pdata->port, pdev->name);
+        if (!ssp) {
+                error = -ENODEV;
+                goto err_free_gpio;
+        }
+
+        /* HaRET does not disable devices before jumping into Linux */
+        if (pxa_ssp_read_reg(ssp, SSCR0) & SSCR0_SSE) {
+                pxa_ssp_write_reg(ssp, SSCR0, 0);
+                dev_warn(&pdev->dev, "ssp%d already enabled\n", pdata->port);
+        }
+
+        navpoint = kzalloc(sizeof(*navpoint), GFP_KERNEL);
+        input = input_allocate_device();
+        if (!navpoint || !input) {
+                error = -ENOMEM;
+                goto err_free_mem;
+        }
+
+        navpoint->ssp = ssp;
+        navpoint->input = input;
+        navpoint->dev = &pdev->dev;
+        navpoint->gpio = pdata->gpio;
+
+        input->name = pdev->name;
+        input->dev.parent = &pdev->dev;
+
+        __set_bit(EV_KEY, input->evbit);
+        __set_bit(EV_ABS, input->evbit);
+        __set_bit(BTN_LEFT, input->keybit);
+        __set_bit(BTN_TOUCH, input->keybit);
+        __set_bit(BTN_TOOL_FINGER, input->keybit);
+
+        input_set_abs_params(input, ABS_X,
+                             NAVPOINT_X_MIN, NAVPOINT_X_MAX, 0, 0);
+        input_set_abs_params(input, ABS_Y,
+                             NAVPOINT_Y_MIN, NAVPOINT_Y_MAX, 0, 0);
+        input_set_abs_params(input, ABS_PRESSURE,
+                             NAVPOINT_PRESSURE_MIN, NAVPOINT_PRESSURE_MAX,
+                             0, 0);
+
+        input->open = navpoint_open;
+        input->close = navpoint_close;
+
+        input_set_drvdata(input, navpoint);
+
+        error = request_irq(ssp->irq, navpoint_irq, 0, pdev->name, navpoint);
+        if (error)
+                goto err_free_mem;
+
+        error = input_register_device(input);
+        if (error)
+                goto err_free_irq;
+
+        platform_set_drvdata(pdev, navpoint);
+        dev_dbg(&pdev->dev, "ssp%d, irq %d\n", pdata->port, ssp->irq);
+
+        return 0;
+
+err_free_irq:
+        free_irq(ssp->irq, &pdev->dev);
+err_free_mem:
+        input_free_device(input);
+        kfree(navpoint);
+        pxa_ssp_free(ssp);
+err_free_gpio:
+        if (gpio_is_valid(pdata->gpio))
+                gpio_free(pdata->gpio);
+
+        return error;
+}
+
+static int __devexit navpoint_remove(struct platform_device *pdev)
+{
+        const struct navpoint_platform_data *pdata =
+                                        dev_get_platdata(&pdev->dev);
+        struct navpoint *navpoint = platform_get_drvdata(pdev);
+        struct ssp_device *ssp = navpoint->ssp;
+
+        free_irq(ssp->irq, navpoint);
+
+        input_unregister_device(navpoint->input);
+        kfree(navpoint);
+
+        pxa_ssp_free(ssp);
+
+        if (gpio_is_valid(pdata->gpio))
+                gpio_free(pdata->gpio);
+
+        return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int navpoint_suspend(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct navpoint *navpoint = platform_get_drvdata(pdev);
+        struct input_dev *input = navpoint->input;
+
+        mutex_lock(&input->mutex);
+        if (input->users)
+                navpoint_down(navpoint);
+        mutex_unlock(&input->mutex);
+
+        return 0;
+}
+
+static int navpoint_resume(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct navpoint *navpoint = platform_get_drvdata(pdev);
+        struct input_dev *input = navpoint->input;
+
+        mutex_lock(&input->mutex);
+        if (input->users)
+                navpoint_up(navpoint);
+        mutex_unlock(&input->mutex);
+
+        return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(navpoint_pm_ops, navpoint_suspend, navpoint_resume);
+
+static struct platform_driver navpoint_driver = {
+        .probe          = navpoint_probe,
+        .remove         = __devexit_p(navpoint_remove),
+        .driver = {
+                .name   = "navpoint",
+                .owner  = THIS_MODULE,
+                .pm     = &navpoint_pm_ops,
+        },
+};
+
+module_platform_driver(navpoint_driver);
+
+MODULE_AUTHOR("Paul Parsons <lost.distance@yahoo.com>");
+MODULE_DESCRIPTION("Synaptics NavPoint (PXA27x SSP/SPI) driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:navpoint");