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Subject[PATCH 06/37] Input: WM97xx - add chip driver for WM9712 touchscreen
From
Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Graeme Gregory <gg@opensource.wolfsonmicro.com>
Signed-off-by: Mike Arthur <mike.arthur@wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Lars Munch <lars@segv.dk>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---
drivers/input/touchscreen/Kconfig | 9 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/wm9712.c | 462 ++++++++++++++++++++++++++++++++++++
3 files changed, 472 insertions(+), 0 deletions(-)
create mode 100644 drivers/input/touchscreen/wm9712.c
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 4939a96..240e441 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -208,6 +208,15 @@ config TOUCHSCREEN_WM9705

If unsure, say N.

+config TOUCHSCREEN_WM9712
+ bool "WM9712 Touchscreen interface support"
+ depends on TOUCHSCREEN_WM97XX
+ help
+ Say Y here if you have a Wolfson Microelectronics WM9712
+ touchscreen controller connected to your system.
+
+ If unsure, say N.
+
config TOUCHSCREEN_USB_COMPOSITE
tristate "USB Touchscreen Driver"
depends on USB_ARCH_HAS_HCD
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 5829a43..eb57f66 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -23,3 +23,4 @@ obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN) += touchwin.o
obj-$(CONFIG_TOUCHSCREEN_UCB1400) += ucb1400_ts.o
obj-$(CONFIG_TOUCHSCREEN_WM97XX) += wm97xx-ts.o
wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9705) += wm9705.o
+wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9712) += wm9712.o
diff --git a/drivers/input/touchscreen/wm9712.c b/drivers/input/touchscreen/wm9712.c
new file mode 100644
index 0000000..0b6e4cf
--- /dev/null
+++ b/drivers/input/touchscreen/wm9712.c
@@ -0,0 +1,462 @@
+/*
+ * wm9712.c -- Codec driver for Wolfson WM9712 AC97 Codecs.
+ *
+ * Copyright 2003, 2004, 2005, 2006, 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>
+ * Russell King <rmk@arm.linux.org.uk>
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/input.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
+#include <linux/wm97xx.h>
+
+#define TS_NAME "wm97xx"
+#define WM9712_VERSION "1.00"
+#define DEFAULT_PRESSURE 0xb0c0
+
+/*
+ * Module parameters
+ */
+
+/*
+ * Set internal pull up for pen detect.
+ *
+ * Pull up is in the range 1.02k (least sensitive) to 64k (most sensitive)
+ * i.e. pull up resistance = 64k Ohms / rpu.
+ *
+ * Adjust this value if you are having problems with pen detect not
+ * detecting any down event.
+ */
+static int rpu = 8;
+module_param(rpu, int, 0);
+MODULE_PARM_DESC(rpu, "Set internal pull up resitor for pen detect.");
+
+/*
+ * Set current used for pressure measurement.
+ *
+ * Set pil = 2 to use 400uA
+ * pil = 1 to use 200uA and
+ * pil = 0 to disable pressure measurement.
+ *
+ * This is used to increase the range of values returned by the adc
+ * when measureing touchpanel pressure.
+ */
+static int pil;
+module_param(pil, int, 0);
+MODULE_PARM_DESC(pil, "Set current used for pressure measurement.");
+
+/*
+ * Set threshold for pressure measurement.
+ *
+ * Pen down pressure below threshold is ignored.
+ */
+static int pressure = DEFAULT_PRESSURE & 0xfff;
+module_param(pressure, int, 0);
+MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement.");
+
+/*
+ * Set adc sample delay.
+ *
+ * For accurate touchpanel measurements, some settling time may be
+ * required between the switch matrix applying a voltage across the
+ * touchpanel plate and the ADC sampling the signal.
+ *
+ * This delay can be set by setting delay = n, where n is the array
+ * position of the delay in the array delay_table below.
+ * Long delays > 1ms are supported for completeness, but are not
+ * recommended.
+ */
+static int delay = 3;
+module_param(delay, int, 0);
+MODULE_PARM_DESC(delay, "Set adc sample delay.");
+
+/*
+ * Set five_wire = 1 to use a 5 wire touchscreen.
+ *
+ * NOTE: Five wire mode does not allow for readback of pressure.
+ */
+static int five_wire;
+module_param(five_wire, int, 0);
+MODULE_PARM_DESC(five_wire, "Set to '1' to use 5-wire touchscreen.");
+
+/*
+ * Set adc mask function.
+ *
+ * Sources of glitch noise, such as signals driving an LCD display, may feed
+ * through to the touch screen plates and affect measurement accuracy. In
+ * order to minimise this, a signal may be applied to the MASK pin to delay or
+ * synchronise the sampling.
+ *
+ * 0 = No delay or sync
+ * 1 = High on pin stops conversions
+ * 2 = Edge triggered, edge on pin delays conversion by delay param (above)
+ * 3 = Edge triggered, edge on pin starts conversion after delay param
+ */
+static int mask;
+module_param(mask, int, 0);
+MODULE_PARM_DESC(mask, "Set adc mask function.");
+
+/*
+ * Coordinate Polling Enable.
+ *
+ * Set to 1 to enable coordinate polling. e.g. x,y[,p] is sampled together
+ * for every poll.
+ */
+static int coord;
+module_param(coord, int, 0);
+MODULE_PARM_DESC(coord, "Polling coordinate mode");
+
+/*
+ * ADC sample delay times in uS
+ */
+static const int delay_table[] = {
+ 21, /* 1 AC97 Link frames */
+ 42, /* 2 */
+ 84, /* 4 */
+ 167, /* 8 */
+ 333, /* 16 */
+ 667, /* 32 */
+ 1000, /* 48 */
+ 1333, /* 64 */
+ 2000, /* 96 */
+ 2667, /* 128 */
+ 3333, /* 160 */
+ 4000, /* 192 */
+ 4667, /* 224 */
+ 5333, /* 256 */
+ 6000, /* 288 */
+ 0 /* No delay, switch matrix always on */
+};
+
+/*
+ * Delay after issuing a POLL command.
+ *
+ * The delay is 3 AC97 link frames + the touchpanel settling delay
+ */
+static inline void poll_delay(int d)
+{
+ udelay(3 * AC97_LINK_FRAME + delay_table[d]);
+}
+
+/*
+ * set up the physical settings of the WM9712
+ */
+static void wm9712_phy_init(struct wm97xx *wm)
+{
+ u16 dig1 = 0;
+ u16 dig2 = WM97XX_RPR | WM9712_RPU(1);
+
+ /* WM9712 rpu */
+ if (rpu) {
+ dig2 &= 0xffc0;
+ dig2 |= WM9712_RPU(rpu);
+ dev_dbg(wm->dev, "setting pen detect pull-up to %d Ohms",
+ 64000 / rpu);
+ }
+
+ /* touchpanel pressure current*/
+ if (pil == 2) {
+ dig2 |= WM9712_PIL;
+ dev_dbg(wm->dev,
+ "setting pressure measurement current to 400uA.");
+ } else if (pil)
+ dev_dbg(wm->dev,
+ "setting pressure measurement current to 200uA.");
+ if (!pil)
+ pressure = 0;
+
+ /* WM9712 five wire */
+ if (five_wire) {
+ dig2 |= WM9712_45W;
+ dev_dbg(wm->dev, "setting 5-wire touchscreen mode.");
+ }
+
+ /* polling mode sample settling delay */
+ if (delay < 0 || delay > 15) {
+ dev_dbg(wm->dev, "supplied delay out of range.");
+ delay = 4;
+ }
+ dig1 &= 0xff0f;
+ dig1 |= WM97XX_DELAY(delay);
+ dev_dbg(wm->dev, "setting adc sample delay to %d u Secs.",
+ delay_table[delay]);
+
+ /* mask */
+ dig2 |= ((mask & 0x3) << 6);
+ if (mask) {
+ u16 reg;
+ /* Set GPIO4 as Mask Pin*/
+ reg = wm97xx_reg_read(wm, AC97_MISC_AFE);
+ wm97xx_reg_write(wm, AC97_MISC_AFE, reg | WM97XX_GPIO_4);
+ reg = wm97xx_reg_read(wm, AC97_GPIO_CFG);
+ wm97xx_reg_write(wm, AC97_GPIO_CFG, reg | WM97XX_GPIO_4);
+ }
+
+ /* wait - coord mode */
+ if (coord)
+ dig2 |= WM9712_WAIT;
+
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1);
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2);
+}
+
+static void wm9712_dig_enable(struct wm97xx *wm, int enable)
+{
+ u16 dig2 = wm->dig[2];
+
+ if (enable) {
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,
+ dig2 | WM97XX_PRP_DET_DIG);
+ wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD); /* dummy read */
+ } else
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2,
+ dig2 & ~WM97XX_PRP_DET_DIG);
+}
+
+static void wm9712_aux_prepare(struct wm97xx *wm)
+{
+ memcpy(wm->dig_save, wm->dig, sizeof(wm->dig));
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, 0);
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, WM97XX_PRP_DET_DIG);
+}
+
+static void wm9712_dig_restore(struct wm97xx *wm)
+{
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, wm->dig_save[1]);
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, wm->dig_save[2]);
+}
+
+static inline int is_pden(struct wm97xx *wm)
+{
+ return wm->dig[2] & WM9712_PDEN;
+}
+
+/*
+ * Read a sample from the WM9712 adc in polling mode.
+ */
+static int wm9712_poll_sample(struct wm97xx *wm, int adcsel, int *sample)
+{
+ int timeout = 5 * delay;
+
+ if (!wm->pen_probably_down) {
+ u16 data = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
+ if (!(data & WM97XX_PEN_DOWN))
+ return RC_PENUP;
+ wm->pen_probably_down = 1;
+ }
+
+ /* set up digitiser */
+ if (adcsel & 0x8000)
+ adcsel = ((adcsel & 0x7fff) + 3) << 12;
+
+ if (wm->mach_ops && wm->mach_ops->pre_sample)
+ wm->mach_ops->pre_sample(adcsel);
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1,
+ adcsel | WM97XX_POLL | WM97XX_DELAY(delay));
+
+ /* wait 3 AC97 time slots + delay for conversion */
+ poll_delay(delay);
+
+ /* wait for POLL to go low */
+ while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL)
+ && timeout) {
+ udelay(AC97_LINK_FRAME);
+ timeout--;
+ }
+
+ if (timeout <= 0) {
+ /* If PDEN is set, we can get a timeout when pen goes up */
+ if (is_pden(wm))
+ wm->pen_probably_down = 0;
+ else
+ dev_dbg(wm->dev, "adc sample timeout");
+ return RC_PENUP;
+ }
+
+ *sample = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
+ if (wm->mach_ops && wm->mach_ops->post_sample)
+ wm->mach_ops->post_sample(adcsel);
+
+ /* check we have correct sample */
+ if ((*sample & WM97XX_ADCSEL_MASK) != adcsel) {
+ dev_dbg(wm->dev, "adc wrong sample, read %x got %x", adcsel,
+ *sample & WM97XX_ADCSEL_MASK);
+ return RC_PENUP;
+ }
+
+ if (!(*sample & WM97XX_PEN_DOWN)) {
+ wm->pen_probably_down = 0;
+ return RC_PENUP;
+ }
+
+ return RC_VALID;
+}
+
+/*
+ * Read a coord from the WM9712 adc in polling mode.
+ */
+static int wm9712_poll_coord(struct wm97xx *wm, struct wm97xx_data *data)
+{
+ int timeout = 5 * delay;
+
+ if (!wm->pen_probably_down) {
+ u16 data_rd = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
+ if (!(data_rd & WM97XX_PEN_DOWN))
+ return RC_PENUP;
+ wm->pen_probably_down = 1;
+ }
+
+ /* set up digitiser */
+ if (wm->mach_ops && wm->mach_ops->pre_sample)
+ wm->mach_ops->pre_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
+
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1,
+ WM97XX_COO | WM97XX_POLL | WM97XX_DELAY(delay));
+
+ /* wait 3 AC97 time slots + delay for conversion and read x */
+ poll_delay(delay);
+ data->x = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
+ /* wait for POLL to go low */
+ while ((wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER1) & WM97XX_POLL)
+ && timeout) {
+ udelay(AC97_LINK_FRAME);
+ timeout--;
+ }
+
+ if (timeout <= 0) {
+ /* If PDEN is set, we can get a timeout when pen goes up */
+ if (is_pden(wm))
+ wm->pen_probably_down = 0;
+ else
+ dev_dbg(wm->dev, "adc sample timeout");
+ return RC_PENUP;
+ }
+
+ /* read back y data */
+ data->y = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
+ if (pil)
+ data->p = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD);
+ else
+ data->p = DEFAULT_PRESSURE;
+
+ if (wm->mach_ops && wm->mach_ops->post_sample)
+ wm->mach_ops->post_sample(WM97XX_ADCSEL_X | WM97XX_ADCSEL_Y);
+
+ /* check we have correct sample */
+ if (!(data->x & WM97XX_ADCSEL_X) || !(data->y & WM97XX_ADCSEL_Y))
+ goto err;
+ if (pil && !(data->p & WM97XX_ADCSEL_PRES))
+ goto err;
+
+ if (!(data->x & WM97XX_PEN_DOWN) || !(data->y & WM97XX_PEN_DOWN)) {
+ wm->pen_probably_down = 0;
+ return RC_PENUP;
+ }
+ return RC_VALID;
+err:
+ return 0;
+}
+
+/*
+ * Sample the WM9712 touchscreen in polling mode
+ */
+static int wm9712_poll_touch(struct wm97xx *wm, struct wm97xx_data *data)
+{
+ int rc;
+
+ if (coord) {
+ rc = wm9712_poll_coord(wm, data);
+ if (rc != RC_VALID)
+ return rc;
+ } else {
+ rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_X, &data->x);
+ if (rc != RC_VALID)
+ return rc;
+
+ rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_Y, &data->y);
+ if (rc != RC_VALID)
+ return rc;
+
+ if (pil && !five_wire) {
+ rc = wm9712_poll_sample(wm, WM97XX_ADCSEL_PRES,
+ &data->p);
+ if (rc != RC_VALID)
+ return rc;
+ } else
+ data->p = DEFAULT_PRESSURE;
+ }
+ return RC_VALID;
+}
+
+/*
+ * Enable WM9712 continuous mode, i.e. touch data is streamed across
+ * an AC97 slot
+ */
+static int wm9712_acc_enable(struct wm97xx *wm, int enable)
+{
+ u16 dig1, dig2;
+ int ret = 0;
+
+ dig1 = wm->dig[1];
+ dig2 = wm->dig[2];
+
+ if (enable) {
+ /* continous mode */
+ if (wm->mach_ops->acc_startup) {
+ ret = wm->mach_ops->acc_startup(wm);
+ if (ret < 0)
+ return ret;
+ }
+ dig1 &= ~(WM97XX_CM_RATE_MASK | WM97XX_ADCSEL_MASK |
+ WM97XX_DELAY_MASK | WM97XX_SLT_MASK);
+ dig1 |= WM97XX_CTC | WM97XX_COO | WM97XX_SLEN |
+ WM97XX_DELAY(delay) |
+ WM97XX_SLT(wm->acc_slot) |
+ WM97XX_RATE(wm->acc_rate);
+ if (pil)
+ dig1 |= WM97XX_ADCSEL_PRES;
+ dig2 |= WM9712_PDEN;
+ } else {
+ dig1 &= ~(WM97XX_CTC | WM97XX_COO | WM97XX_SLEN);
+ dig2 &= ~WM9712_PDEN;
+ if (wm->mach_ops->acc_shutdown)
+ wm->mach_ops->acc_shutdown(wm);
+ }
+
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER1, dig1);
+ wm97xx_reg_write(wm, AC97_WM97XX_DIGITISER2, dig2);
+
+ return 0;
+}
+
+struct wm97xx_codec_drv wm9712_codec = {
+ .id = WM9712_ID2,
+ .name = "wm9712",
+ .poll_sample = wm9712_poll_sample,
+ .poll_touch = wm9712_poll_touch,
+ .acc_enable = wm9712_acc_enable,
+ .phy_init = wm9712_phy_init,
+ .dig_enable = wm9712_dig_enable,
+ .dig_restore = wm9712_dig_restore,
+ .aux_prepare = wm9712_aux_prepare,
+};
+EXPORT_SYMBOL_GPL(wm9712_codec);
+
+/* Module information */
+MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>");
+MODULE_DESCRIPTION("WM9712 Touch Screen Driver");
+MODULE_LICENSE("GPL");
--
1.5.5.rc2.6.gf58d



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