[PATCH 5/6] Driver for WM97xx touchscreens in streaming mode on Mainstone

Mark Brown
2008-01-26T17:30:46Z

Cc: Vince Sanders <vince@kyllikki.org>
Cc: Andrew Zabolotny <zap@homelink.ru>
---
drivers/input/touchscreen/mainstone-wm97xx.c | 298 ++++++++++++++++++++++++++
1 files changed, 298 insertions(+), 0 deletions(-)
create mode 100644 drivers/input/touchscreen/mainstone-wm97xx.c

diff --git a/drivers/input/touchscreen/mainstone-wm97xx.c b/drivers/input/touchscreen/mainstone-wm97xx.c
new file mode 100644
index 0000000..8e1c35d
--- /dev/null
+++ b/drivers/input/touchscreen/mainstone-wm97xx.c
@@ -0,0 +1,298 @@
+/*
+ * mainstone-wm97xx.c -- Mainstone Continuous Touch screen driver for
+ * Wolfson WM97xx AC97 Codecs.
+ *
+ * Copyright 2004, 2007 Wolfson Microelectronics PLC.
+ * Author: Liam Girdwood
+ * liam.girdwood@wolfsonmicro.com or linux@wolfsonmicro.com
+ * Parts Copyright : Ian Molton <spyro@f2s.com>
+ * Andrew Zabolotny <zap@homelink.ru>
+ *
+ * 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.
+ *
+ * Notes:
+ * This is a wm97xx extended touch driver to capture touch
+ * data in a continuous manner on the Intel XScale archictecture
+ *
+ * Features:
+ * - codecs supported:- WM9705, WM9712, WM9713
+ * - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/wm97xx.h>
+#include <linux/io.h>
+#include <asm/arch/pxa-regs.h>
+
+#define VERSION "0.13"
+
+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[] = {
+ {WM9705_ID2, 0, WM_READS(94), 94},
+ {WM9705_ID2, 1, WM_READS(188), 188},
+ {WM9705_ID2, 2, WM_READS(375), 375},
+ {WM9705_ID2, 3, WM_READS(750), 750},
+ {WM9712_ID2, 0, WM_READS(94), 94},
+ {WM9712_ID2, 1, WM_READS(188), 188},
+ {WM9712_ID2, 2, WM_READS(375), 375},
+ {WM9712_ID2, 3, WM_READS(750), 750},
+ {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;
+static u16 last, tries;
+
+/*
+ * 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)");
+
+/*
+ * Pen down detection.
+ *
+ * This driver can either poll or use an interrupt to indicate a pen down
+ * event. If the irq request fails then it will fall back to polling mode.
+ */
+static int pen_int;
+module_param(pen_int, int, 0);
+MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
+
+/*
+ * 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 on pxa machines */
+#ifdef CONFIG_PXA27x
+static void wm97xx_acc_pen_up(struct wm97xx *wm)
+{
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(1);
+
+ while (MISR & (1 << 2))
+ MODR;
+}
+#else
+static void wm97xx_acc_pen_up(struct wm97xx *wm)
+{
+ int count = 16;
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(1);
+
+ while (count < 16) {
+ MODR;
+ count--;
+ }
+}
+#endif
+
+static int wm97xx_acc_pen_down(struct wm97xx *wm)
+{
+ u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
+ int reads = 0;
+
+ /* data is never immediately available after pen down irq */
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(1);
+
+ if (tries > 5) {
+ tries = 0;
+ return RC_PENUP;
+ }
+
+ x = MODR;
+ if (x == last) {
+ tries++;
+ return RC_AGAIN;
+ }
+ last = x;
+ do {
+ if (reads)
+ x = MODR;
+ y = MODR;
+ if (pressure)
+ p = MODR;
+
+ /* are samples valid */
+ if ((x & 0x7000) != WM97XX_ADCSEL_X ||
+ (y & 0x7000) != WM97XX_ADCSEL_Y ||
+ (p & 0x7000) != 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_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 = 0;
+
+ /* 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,
+ "mainstone accelerated touchscreen driver, %d samples/sec\n",
+ cinfo[sp_idx].speed);
+
+ /* codec specific irq config */
+ if (pen_int) {
+ switch (wm->id) {
+ case WM9705_ID2:
+ wm->pen_irq = IRQ_GPIO(4);
+ set_irq_type(IRQ_GPIO(4), IRQT_BOTHEDGE);
+ break;
+ case WM9712_ID2:
+ case WM9713_ID2:
+ /* enable pen down interrupt */
+ /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
+ wm->pen_irq = MAINSTONE_AC97_IRQ;
+ 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);
+ break;
+ default:
+ dev_err(wm->dev,
+ "pen down irq not supported on this device\n");
+ pen_int = 0;
+ break;
+ }
+ }
+
+ return 0;
+}
+
+static void wm97xx_acc_shutdown(struct wm97xx *wm)
+{
+ /* codec specific deconfig */
+ if (pen_int) {
+ switch (wm->id & 0xffff) {
+ case WM9705_ID2:
+ wm->pen_irq = 0;
+ break;
+ case WM9712_ID2:
+ case WM9713_ID2:
+ /* disable interrupt */
+ wm->pen_irq = 0;
+ break;
+ }
+ }
+}
+
+static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
+{
+ if (enable)
+ enable_irq(wm->pen_irq);
+ else
+ disable_irq(wm->pen_irq);
+}
+
+static struct wm97xx_mach_ops mainstone_mach_ops = {
+ .acc_enabled = 1,
+ .acc_pen_up = wm97xx_acc_pen_up,
+ .acc_pen_down = wm97xx_acc_pen_down,
+ .acc_startup = wm97xx_acc_startup,
+ .acc_shutdown = wm97xx_acc_shutdown,
+ .irq_enable = wm97xx_irq_enable,
+};
+
+static int mainstone_wm97xx_probe(struct platform_device *pdev)
+{
+ struct wm97xx *wm = platform_get_drvdata(pdev);
+ return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
+}
+
+static int mainstone_wm97xx_remove(struct platform_device *pdev)
+{
+ struct wm97xx *wm = platform_get_drvdata(pdev);
+ wm97xx_unregister_mach_ops(wm);
+ return 0;
+}
+
+static struct platform_driver mainstone_wm97xx_driver = {
+ .probe = mainstone_wm97xx_probe,
+ .remove = mainstone_wm97xx_remove,
+ .driver = {
+ .name = "wm97xx-touch",
+ },
+};
+
+static int __init mainstone_wm97xx_init(void)
+{
+ return platform_driver_register(&mainstone_wm97xx_driver);
+}
+
+static void __exit mainstone_wm97xx_exit(void)
+{
+ platform_driver_unregister(&mainstone_wm97xx_driver);
+}
+
+module_init(mainstone_wm97xx_init);
+module_exit(mainstone_wm97xx_exit);
+
+/* Module information */
+MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>");
+MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
+MODULE_LICENSE("GPL");
--
1.5.3.8