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Subject[PATCH 5/5] input: STMPE touch controller support
Date
This one adds a driver for STMPE touchscreen controllers. This driver depends on
stmpexxx mfd core driver.

Signed-off-by: Luotao Fu <l.fu@pengutronix.de>

---
V2 Changes:
* include subsystem headers since they are now remove from the mfd
core header file
* use genirq to register threaded isr. The stmpe811 own irq callbacks
are dropped in the core driver.
* use STMPE811_TS_NAME for name all over the place
* wait for completion of core IO operation before cancelling polling of
release event.
* switch to platform data for configuration parameters.
* add FIFO reset to open callback, also reset FIFO before reporting
release.
V3 Changes:
* reformated platform data comments to kernel-doc style

V4 Changes:
* converted to stmpexxx core by Rabin Vincent <rabin.vincent@stericsson.com>
* wait for running workqueue callback to finish while canceling the queue
* add i_drive configuration support

V5 Changes:
* add ADC block enable to stmpe_enable call.

V6 Changes:
* add _reset_fifo callback to reduce duplicated code.
* fix mask usage while setting bits in probe.
* acquire platform irq by name

drivers/input/touchscreen/Kconfig | 10 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/stmpe-ts.c | 378 ++++++++++++++++++++++++++++++++++
3 files changed, 389 insertions(+), 0 deletions(-)
create mode 100644 drivers/input/touchscreen/stmpe-ts.c
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 3b9d5e2..96a9954 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -603,4 +603,14 @@ config TOUCHSCREEN_TPS6507X
To compile this driver as a module, choose M here: the
module will be called tps6507x_ts.

+config TOUCHSCREEN_STMPE
+ tristate "STMicroelectronics STMPE touchscreens"
+ depends on MFD_STMPE
+ help
+ Say Y here if you want support for STMicroelectronics
+ STMPE touchscreen controllers.
+
+ To compile this driver as a module, choose M here: the
+ module will be called stmpe-ts.
+
endif
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 497964a..2691c62 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -47,3 +47,4 @@ obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE) += mainstone-wm97xx.o
obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE) += zylonite-wm97xx.o
obj-$(CONFIG_TOUCHSCREEN_W90X900) += w90p910_ts.o
obj-$(CONFIG_TOUCHSCREEN_TPS6507X) += tps6507x-ts.o
+obj-$(CONFIG_TOUCHSCREEN_STMPE) += stmpe-ts.o
diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c
new file mode 100644
index 0000000..7742e63
--- /dev/null
+++ b/drivers/input/touchscreen/stmpe-ts.c
@@ -0,0 +1,378 @@
+/* STMicroelectronics STMPE811 Touchscreen Driver
+ *
+ * (C) 2010 Luotao Fu <l.fu@pengutronix.de>
+ * All rights reserved.
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/workqueue.h>
+
+#include <linux/mfd/stmpe.h>
+
+/* Register layouts and functionalities are identical on all stmpexxx variants
+ * with touchscreen controller
+ */
+#define STMPE_REG_INT_STA 0x0B
+#define STMPE_REG_ADC_CTRL1 0x20
+#define STMPE_REG_ADC_CTRL2 0x21
+#define STMPE_REG_TSC_CTRL 0x40
+#define STMPE_REG_TSC_CFG 0x41
+#define STMPE_REG_FIFO_TH 0x4A
+#define STMPE_REG_FIFO_STA 0x4B
+#define STMPE_REG_FIFO_SIZE 0x4C
+#define STMPE_REG_TSC_DATA_XYZ 0x52
+#define STMPE_REG_TSC_FRACTION_Z 0x56
+#define STMPE_REG_TSC_I_DRIVE 0x58
+
+#define OP_MOD_XYZ 0
+
+#define STMPE_TSC_CTRL_TSC_EN (1<<0)
+
+#define STMPE_FIFO_STA_RESET (1<<0)
+
+#define STMPE_IRQ_TOUCH_DET 0
+
+#define SAMPLE_TIME(x) ((x & 0xf) << 4)
+#define MOD_12B(x) ((x & 0x1) << 3)
+#define REF_SEL(x) ((x & 0x1) << 1)
+#define ADC_FREQ(x) (x & 0x3)
+#define AVE_CTRL(x) ((x & 0x3) << 6)
+#define DET_DELAY(x) ((x & 0x7) << 3)
+#define SETTLING(x) (x & 0x7)
+#define FRACTION_Z(x) (x & 0x7)
+#define I_DRIVE(x) (x & 0x1)
+#define OP_MODE(x) ((x & 0x7) << 1)
+
+#define STMPE_TS_NAME "stmpe-ts"
+#define XY_MASK 0xfff
+
+struct stmpe_touch {
+ struct stmpe *stmpe;
+ struct input_dev *idev;
+ struct delayed_work work;
+ u8 sample_time;
+ u8 mod_12b;
+ u8 ref_sel;
+ u8 adc_freq;
+ u8 ave_ctrl;
+ u8 touch_det_delay;
+ u8 settling;
+ u8 fraction_z;
+ u8 i_drive;
+};
+
+static int inline __stmpe_reset_fifo(struct stmpe *stmpe)
+{
+ int ret;
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
+ STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET);
+ if (ret)
+ return ret;
+
+ return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
+ STMPE_FIFO_STA_RESET, 0);
+}
+
+static void stmpe_work(struct work_struct *work)
+{
+ int int_sta;
+ u32 timeout = 40;
+
+ struct stmpe_touch *ts =
+ container_of(work, struct stmpe_touch, work.work);
+
+ int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
+
+ /* touch_det sometimes get desasserted or just get stuck. This appears
+ * to be a silicon bug, We still have to clearify this with the
+ * manufacture. As a workaround We release the key anyway if the
+ * touch_det keeps coming in after 4ms, while the FIFO contains no value
+ * during the whole time. */
+ while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) {
+ timeout--;
+ int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
+ udelay(100);
+ }
+
+ /* reset the FIFO before we report release event */
+ __stmpe_reset_fifo(ts->stmpe);
+
+ input_report_abs(ts->idev, ABS_PRESSURE, 0);
+ input_sync(ts->idev);
+}
+
+static irqreturn_t stmpe_ts_handler(int irq, void *data)
+{
+ u8 data_set[4];
+ int x, y, z;
+ struct stmpe_touch *ts = data;
+
+ /* Cancel scheduled polling for release if we have new value
+ * available. Wait if the polling is already running. */
+ cancel_delayed_work_sync(&ts->work);
+
+ /*
+ * The FIFO sometimes just crashes and stops generating interrupts. This
+ * appears to be a silicon bug. We still have to clearify this with
+ * the manufacture. As a workaround we disable the TSC while we are
+ * collecting data and flush the FIFO after reading
+ */
+ stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+ STMPE_TSC_CTRL_TSC_EN, 0);
+
+ stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set);
+
+ x = (data_set[0] << 4) | (data_set[1] >> 4);
+ y = ((data_set[1] & 0xf) << 8) | data_set[2];
+ z = data_set[3];
+
+ input_report_abs(ts->idev, ABS_X, x);
+ input_report_abs(ts->idev, ABS_Y, y);
+ input_report_abs(ts->idev, ABS_PRESSURE, z);
+ input_sync(ts->idev);
+
+ /* flush the FIFO after we have read out our values. */
+ __stmpe_reset_fifo(ts->stmpe);
+
+ /* reenable the tsc */
+ stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+ STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
+
+ /* start polling for touch_det to detect release */
+ schedule_delayed_work(&ts->work, HZ / 50);
+
+ return IRQ_HANDLED;
+}
+
+static int stmpe_ts_open(struct input_dev *dev)
+{
+ struct stmpe_touch *ts = input_get_drvdata(dev);
+ int ret = 0;
+
+ ret = __stmpe_reset_fifo(ts->stmpe);
+ if (ret)
+ return ret;
+
+ return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+ STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
+}
+
+static void stmpe_ts_close(struct input_dev *dev)
+{
+ struct stmpe_touch *ts = input_get_drvdata(dev);
+
+ stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+ STMPE_TSC_CTRL_TSC_EN, 0);
+}
+
+static int __devinit stmpe_input_probe(struct platform_device *pdev)
+{
+ struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
+ struct stmpe_platform_data *pdata = stmpe->pdata;
+ struct stmpe_touch *ts;
+ struct input_dev *idev;
+ struct stmpe_ts_platform_data *ts_pdata = NULL;
+ int ret = 0;
+ unsigned int ts_irq;
+ u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask;
+
+ ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
+ if (ts_irq < 0)
+ return ts_irq;
+
+ ts = kzalloc(sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ goto err_out;
+
+ idev = input_allocate_device();
+ if (!idev)
+ goto err_free_ts;
+
+ platform_set_drvdata(pdev, ts);
+ ts->stmpe = stmpe;
+ ts->idev = idev;
+
+ if (pdata)
+ ts_pdata = pdata->ts;
+
+ if (ts_pdata) {
+ ts->sample_time = ts_pdata->sample_time;
+ ts->mod_12b = ts_pdata->mod_12b;
+ ts->ref_sel = ts_pdata->ref_sel;
+ ts->adc_freq = ts_pdata->adc_freq;
+ ts->ave_ctrl = ts_pdata->ave_ctrl;
+ ts->touch_det_delay = ts_pdata->touch_det_delay;
+ ts->settling = ts_pdata->settling;
+ ts->fraction_z = ts_pdata->fraction_z;
+ ts->i_drive = ts_pdata->i_drive;
+ }
+
+ INIT_DELAYED_WORK(&ts->work, stmpe_work);
+
+ ret = request_threaded_irq(ts_irq, NULL, stmpe_ts_handler,
+ IRQF_ONESHOT, STMPE_TS_NAME, ts);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq);
+ goto err_free_input;
+ }
+
+ ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not enable clock for ADC and TS\n");
+ goto err_free_irq;
+ }
+
+ adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) |
+ REF_SEL(ts->ref_sel);
+ adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff);
+ ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1,
+ adc_ctrl1_mask, adc_ctrl1);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not setup ADC\n");
+ goto err_free_irq;
+ }
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2,
+ ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq));
+ if (ret) {
+ dev_err(&pdev->dev, "Could not setup ADC\n");
+ goto err_free_irq;
+ }
+
+ tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) |
+ SETTLING(ts->settling);
+ tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff);
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not config touch\n");
+ goto err_free_irq;
+ }
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z,
+ FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z));
+ if (ret) {
+ dev_err(&pdev->dev, "Could not config touch\n");
+ goto err_free_irq;
+ }
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE,
+ I_DRIVE(0xff), I_DRIVE(ts->i_drive));
+ if (ret) {
+ dev_err(&pdev->dev, "Could not config touch\n");
+ goto err_free_irq;
+ }
+
+ /* set FIFO to 1 for single point reading */
+ ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not set FIFO\n");
+ goto err_free_irq;
+ }
+
+ ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL,
+ OP_MODE(0xff), OP_MODE(OP_MOD_XYZ));
+ if (ret) {
+ dev_err(&pdev->dev, "Could not set mode\n");
+ goto err_free_irq;
+ }
+
+ idev->name = STMPE_TS_NAME;
+ idev->id.bustype = BUS_I2C;
+ idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+ idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+ idev->open = stmpe_ts_open;
+ idev->close = stmpe_ts_close;
+
+ input_set_drvdata(idev, ts);
+
+ ret = input_register_device(idev);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not register input device\n");
+ goto err_free_irq;
+ }
+
+ input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0);
+ input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0);
+ input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0);
+
+ return ret;
+
+err_free_irq:
+ free_irq(ts_irq, ts);
+err_free_input:
+ input_free_device(idev);
+ platform_set_drvdata(pdev, NULL);
+err_free_ts:
+ kfree(ts);
+err_out:
+ return ret;
+}
+
+static int __devexit stmpe_ts_remove(struct platform_device *pdev)
+{
+ struct stmpe_touch *ts = platform_get_drvdata(pdev);
+ unsigned int ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
+
+ cancel_delayed_work(&ts->work);
+
+ stmpe_reg_write(ts->stmpe, STMPE_REG_FIFO_TH, 0);
+
+ stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN);
+
+ free_irq(ts_irq, ts);
+
+ platform_set_drvdata(pdev, NULL);
+
+ input_unregister_device(ts->idev);
+ input_free_device(ts->idev);
+
+ kfree(ts);
+
+ return 0;
+}
+
+static struct platform_driver stmpe_ts_driver = {
+ .driver = {
+ .name = STMPE_TS_NAME,
+ },
+ .probe = stmpe_input_probe,
+ .remove = __devexit_p(stmpe_ts_remove),
+};
+
+static int __init stmpe_ts_init(void)
+{
+ return platform_driver_register(&stmpe_ts_driver);
+}
+
+module_init(stmpe_ts_init);
+
+static void __exit stmpe_ts_exit(void)
+{
+ platform_driver_unregister(&stmpe_ts_driver);
+}
+
+module_exit(stmpe_ts_exit);
+
+MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
+MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" STMPE_TS_NAME);
--
1.7.1


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