1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/mainstone-wm97xx.c b/drivers/input/touchscreen/mainstone-wm97xx.c
new file mode 100644
index 000000000..c39f49720
--- /dev/null
+++ b/drivers/input/touchscreen/mainstone-wm97xx.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * mainstone-wm97xx.c  --  Mainstone Continuous Touch screen driver for
+ *                         Wolfson WM97xx AC97 Codecs.
+ *
+ * Copyright 2004, 2007 Wolfson Microelectronics PLC.
+ * Author: Liam Girdwood <lrg@slimlogic.co.uk>
+ * Parts Copyright : Ian Molton <spyro@f2s.com>
+ *                   Andrew Zabolotny <zap@homelink.ru>
+ *
+ * Notes:
+ *     This is a wm97xx extended touch driver to capture touch
+ *     data in a continuous manner on the Intel XScale architecture
+ *
+ *  Features:
+ *       - codecs supported:- WM9705, WM9712, WM9713
+ *       - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
+ */
+
+#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>
+
+#include <asm/mach-types.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[] = {
+	{ 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 struct gpio_desc *gpiod_irq;
+
+/*
+ * 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 */
+static void wm97xx_acc_pen_up(struct wm97xx *wm)
+{
+	unsigned int count;
+
+	msleep(1);
+
+	if (cpu_is_pxa27x()) {
+		while (pxa2xx_ac97_read_misr() & (1 << 2))
+			pxa2xx_ac97_read_modr();
+	} else if (cpu_is_pxa3xx()) {
+		for (count = 0; count < 16; count++)
+			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 = 0, ret = 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);
+
+	/* IRQ driven touchscreen is used on Palm hardware */
+	if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
+		pen_int = 1;
+		/* There is some obscure mutant of WM9712 interbred with WM9713
+		 * used on Palm HW */
+		wm->variant = WM97xx_WM1613;
+	} else if (machine_is_zylonite()) {
+		pen_int = 1;
+	}
+
+	if (pen_int) {
+		gpiod_irq = gpiod_get(wm->dev, "touch", GPIOD_IN);
+		if (IS_ERR(gpiod_irq))
+			pen_int = 0;
+	}
+
+	if (pen_int) {
+		wm->pen_irq = gpiod_to_irq(gpiod_irq);
+		irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
+	}
+
+	/* codec specific irq config */
+	if (pen_int) {
+		switch (wm->id) {
+		case WM9705_ID2:
+			break;
+		case WM9712_ID2:
+		case WM9713_ID2:
+			/* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
+			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 ret;
+}
+
+static void wm97xx_acc_shutdown(struct wm97xx *wm)
+{
+	/* codec specific deconfig */
+	if (pen_int) {
+		if (gpiod_irq)
+			gpiod_put(gpiod_irq);
+		wm->pen_irq = 0;
+	}
+}
+
+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_gpio	= WM97XX_GPIO_2,
+};
+
+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",
+	},
+};
+module_platform_driver(mainstone_wm97xx_driver);
+
+/* Module information */
+MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
+MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
+MODULE_LICENSE("GPL");