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-rw-r--r--drivers/input/touchscreen/zylonite-wm97xx.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/zylonite-wm97xx.c b/drivers/input/touchscreen/zylonite-wm97xx.c
new file mode 100644
index 000000000..a70fe4abe
--- /dev/null
+++ b/drivers/input/touchscreen/zylonite-wm97xx.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * zylonite-wm97xx.c -- Zylonite Continuous Touch screen driver
+ *
+ * Copyright 2004, 2007, 2008 Wolfson Microelectronics PLC.
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ * Parts Copyright : Ian Molton <spyro@f2s.com>
+ * Andrew Zabolotny <zap@homelink.ru>
+ *
+ * Notes:
+ * This is a wm97xx extended touch driver supporting interrupt driven
+ * and continuous operation on Marvell Zylonite development systems
+ * (which have a WM9713 on board).
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/soc/pxa/cpu.h>
+#include <linux/wm97xx.h>
+
+#include <sound/pxa2xx-lib.h>
+
+struct continuous {
+ u16 id; /* codec id */
+ u8 code; /* continuous code */
+ u8 reads; /* number of coord reads per read cycle */
+ u32 speed; /* number of coords per second */
+};
+
+#define WM_READS(sp) ((sp / HZ) + 1)
+
+static const struct continuous cinfo[] = {
+ { WM9713_ID2, 0, WM_READS(94), 94 },
+ { WM9713_ID2, 1, WM_READS(120), 120 },
+ { WM9713_ID2, 2, WM_READS(154), 154 },
+ { WM9713_ID2, 3, WM_READS(188), 188 },
+};
+
+/* continuous speed index */
+static int sp_idx;
+
+/*
+ * Pen sampling frequency (Hz) in continuous mode.
+ */
+static int cont_rate = 200;
+module_param(cont_rate, int, 0);
+MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
+
+/*
+ * Pressure readback.
+ *
+ * Set to 1 to read back pen down pressure
+ */
+static int pressure;
+module_param(pressure, int, 0);
+MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
+
+/*
+ * AC97 touch data slot.
+ *
+ * Touch screen readback data ac97 slot
+ */
+static int ac97_touch_slot = 5;
+module_param(ac97_touch_slot, int, 0);
+MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
+
+
+/* flush AC97 slot 5 FIFO machines */
+static void wm97xx_acc_pen_up(struct wm97xx *wm)
+{
+ int i;
+
+ msleep(1);
+
+ for (i = 0; i < 16; i++)
+ pxa2xx_ac97_read_modr();
+}
+
+static int wm97xx_acc_pen_down(struct wm97xx *wm)
+{
+ u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
+ int reads = 0;
+ static u16 last, tries;
+
+ /* When the AC97 queue has been drained we need to allow time
+ * to buffer up samples otherwise we end up spinning polling
+ * for samples. The controller can't have a suitably low
+ * threshold set to use the notifications it gives.
+ */
+ msleep(1);
+
+ if (tries > 5) {
+ tries = 0;
+ return RC_PENUP;
+ }
+
+ x = pxa2xx_ac97_read_modr();
+ if (x == last) {
+ tries++;
+ return RC_AGAIN;
+ }
+ last = x;
+ do {
+ if (reads)
+ x = pxa2xx_ac97_read_modr();
+ y = pxa2xx_ac97_read_modr();
+ if (pressure)
+ p = pxa2xx_ac97_read_modr();
+
+ dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
+ x, y, p);
+
+ /* are samples valid */
+ if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
+ (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
+ (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
+ goto up;
+
+ /* coordinate is good */
+ tries = 0;
+ input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
+ input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
+ input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
+ input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
+ input_sync(wm->input_dev);
+ reads++;
+ } while (reads < cinfo[sp_idx].reads);
+up:
+ return RC_PENDOWN | RC_AGAIN;
+}
+
+static int wm97xx_acc_startup(struct wm97xx *wm)
+{
+ int idx;
+
+ /* check we have a codec */
+ if (wm->ac97 == NULL)
+ return -ENODEV;
+
+ /* Go you big red fire engine */
+ for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
+ if (wm->id != cinfo[idx].id)
+ continue;
+ sp_idx = idx;
+ if (cont_rate <= cinfo[idx].speed)
+ break;
+ }
+ wm->acc_rate = cinfo[sp_idx].code;
+ wm->acc_slot = ac97_touch_slot;
+ dev_info(wm->dev,
+ "zylonite accelerated touchscreen driver, %d samples/sec\n",
+ cinfo[sp_idx].speed);
+
+ return 0;
+}
+
+static struct wm97xx_mach_ops zylonite_mach_ops = {
+ .acc_enabled = 1,
+ .acc_pen_up = wm97xx_acc_pen_up,
+ .acc_pen_down = wm97xx_acc_pen_down,
+ .acc_startup = wm97xx_acc_startup,
+ .irq_gpio = WM97XX_GPIO_2,
+};
+
+static int zylonite_wm97xx_probe(struct platform_device *pdev)
+{
+ struct wm97xx *wm = platform_get_drvdata(pdev);
+ struct gpio_desc *gpio_touch_irq;
+ int err;
+
+ gpio_touch_irq = devm_gpiod_get(&pdev->dev, "touch", GPIOD_IN);
+ err = PTR_ERR_OR_ZERO(gpio_touch_irq);
+ if (err) {
+ dev_err(&pdev->dev, "Cannot get irq gpio: %d\n", err);
+ return err;
+ }
+
+ wm->pen_irq = gpiod_to_irq(gpio_touch_irq);
+ irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
+
+ wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
+ WM97XX_GPIO_POL_HIGH,
+ WM97XX_GPIO_STICKY,
+ WM97XX_GPIO_WAKE);
+ wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
+ WM97XX_GPIO_POL_HIGH,
+ WM97XX_GPIO_NOTSTICKY,
+ WM97XX_GPIO_NOWAKE);
+
+ return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
+}
+
+static int zylonite_wm97xx_remove(struct platform_device *pdev)
+{
+ struct wm97xx *wm = platform_get_drvdata(pdev);
+
+ wm97xx_unregister_mach_ops(wm);
+
+ return 0;
+}
+
+static struct platform_driver zylonite_wm97xx_driver = {
+ .probe = zylonite_wm97xx_probe,
+ .remove = zylonite_wm97xx_remove,
+ .driver = {
+ .name = "wm97xx-touch",
+ },
+};
+module_platform_driver(zylonite_wm97xx_driver);
+
+/* Module information */
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
+MODULE_LICENSE("GPL");