[PATCH 2/4] input: touchscreen: crtouch_ts: Add driver
Tony Felice
tony.felice at timesys.com
Mon Jun 27 18:50:14 UTC 2016
Hi Dmitry, Stefan,
Thanks for your valuable feedback, I really appreciate it. I will review
and submit V2 patchset based on this. Please see a few comments in-line.
-Tony
On Fri, Jun 24, 2016 at 6:04 PM, Dmitry Torokhov <dmitry.torokhov at gmail.com>
wrote:
> Hi Anthony,
>
> On Fri, Jun 24, 2016 at 03:44:44PM -0400, Anthony Felice wrote:
> > Add driver for the Vybrid Tower CRTouch-based touchscreen. This is
> > required for the touchscreen on the TWR-LCD-RGB to work on the Vybrid
> > Tower platform.
> >
> > There is a known issue with this driver: rarely, SW1 on the TWR-LCD-RGB
> > module needs to be pressed in order for the touchscreen to begin
> > functioning.
>
> Hmm. Could it be that you want level interrupt and not edge? Or maybe
> you want to read state after requesting interrupt?
>
I dug up an old email thread about this - According to this, the reason for
the failure is the crtouch chip is configured with the CRTSLEEP bit
initially set. This means the chip goes into sleep mode between touchscreen
scans, and if the host tries to access it during this time it will start to
wake up, but will NAK until it is initialized. The hardware solution is
to tie the WAKEUP pin low on the crtouch chip; otherwise, the driver needs
to run a loop to clear the CRTSLEEP bit in the crtouch configuration
register to prevent the device from sleeping. I will investigate further,
if this is the solution I will include as part of V2 patchset.
>
> > Signed-off-by: Anthony Felice <tony.felice at timesys.com>
> > ---
> > .../bindings/input/touchscreen/crtouch_ts.txt | 14 ++
> > drivers/input/touchscreen/Kconfig | 10 +
> > drivers/input/touchscreen/Makefile | 1 +
> > drivers/input/touchscreen/crtouch_ts.c | 279
> +++++++++++++++++++++
> > 4 files changed, 304 insertions(+)
> > create mode 100644
> Documentation/devicetree/bindings/input/touchscreen/crtouch_ts.txt
> > create mode 100644 drivers/input/touchscreen/crtouch_ts.c
> >
> > diff --git
> a/Documentation/devicetree/bindings/input/touchscreen/crtouch_ts.txt
> b/Documentation/devicetree/bindings/input/touchscreen/crtouch_ts.txt
> > new file mode 100644
> > index 0000000..cfb966c
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/input/touchscreen/crtouch_ts.txt
> > @@ -0,0 +1,14 @@
> > +* Freescale CRTOUCH based touchscreen
> > +
> > +Required Properties:
> > +- compatible must be fsl,crtouch_ts
> > +- reg: I2C address of the touchscreen
> > +- irq-gpio: GPIO to use as event IRQ
> > +
> > +Example:
> > +
> > + touch: crtouch at 49 {
> > + compatible = "fsl,crtouch_ts";
> > + reg = <0x49>;
> > + irq-gpio = <&gpio0 21 GPIO_ACTIVE_HIGH>;
>
> You are not using it as gpio but only as interrupt source, so please
> set it up as regular interrupt and let I2C core set it up for you so
> that you will only need to call request_irq(client->irq, ...)
>
> interrupts = <&gpio0 21 IRQ_TYPE_EDGE_FALLING>;
>
> > + };
> > diff --git a/drivers/input/touchscreen/Kconfig
> b/drivers/input/touchscreen/Kconfig
> > index 8ecdc38..799e342 100644
> > --- a/drivers/input/touchscreen/Kconfig
> > +++ b/drivers/input/touchscreen/Kconfig
> > @@ -1155,4 +1155,14 @@ config TOUCHSCREEN_ROHM_BU21023
> > To compile this driver as a module, choose M here: the
> > module will be called bu21023_ts.
> >
> > +config TOUCHSCREEN_CRTOUCH
> > + tristate "Freescale CRTOUCH based touchscreen"
> > + depends on I2C
> > + help
> > + Say Y here if you have a CRTOUCH based touchscreen
> > + controller.
> > +
> > + To compile this driver as a module, choose M here: the
> > + module will be called crtouch_ts.
> > +
> > endif
> > diff --git a/drivers/input/touchscreen/Makefile
> b/drivers/input/touchscreen/Makefile
> > index f42975e..8cb0a7a 100644
> > --- a/drivers/input/touchscreen/Makefile
> > +++ b/drivers/input/touchscreen/Makefile
> > @@ -95,3 +95,4 @@ obj-$(CONFIG_TOUCHSCREEN_TPS6507X) += tps6507x-ts.o
> > obj-$(CONFIG_TOUCHSCREEN_ZFORCE) += zforce_ts.o
> > obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50) += colibri-vf50-ts.o
> > obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023) += rohm_bu21023.o
> > +obj-$(CONFIG_TOUCHSCREEN_CRTOUCH) += crtouch_ts.o
> > diff --git a/drivers/input/touchscreen/crtouch_ts.c
> b/drivers/input/touchscreen/crtouch_ts.c
> > new file mode 100644
> > index 0000000..bb87a8e
> > --- /dev/null
> > +++ b/drivers/input/touchscreen/crtouch_ts.c
> > @@ -0,0 +1,279 @@
> > +/*
> > + * Driver for Freescale Semiconductor CRTOUCH - A Resistive and
> Capacitive
> > + * touch device with i2c interface
> > + *
> > + * Copyright 2012 Freescale Semiconductor, Inc.
> > + *
> > + * 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/init.h>
> > +#include <linux/i2c.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/input.h>
> > +#include <linux/input/mt.h>
> > +#include <linux/slab.h>
> > +#include <linux/bitops.h>
> > +#include <linux/gpio.h>
> > +#include <linux/of.h>
> > +#include <linux/of_gpio.h>
> > +
> > +/* Resistive touch sense status registers */
> > +#define RES_STA_ERROR 0x00
> > +#define RES_STA_STATUS1 0x01
> > +#define RES_STA_STATUS2 0x02
> > +#define RES_STA_X_MSB 0x03
> > +#define RES_STA_X_LSB 0x04
> > +#define RES_STA_Y_MSB 0x05
> > +#define RES_STA_Y_LSB 0x06
> > +#define RES_STA_PRES_MSB 0x07
> > +#define RES_STA_RRES_LSB 0x08
> > +#define RES_STA_FIFO_STATUS 0x09
> > +#define RES_STA_FIFO_X_MSB 0x0a
> > +#define RES_STA_FIFO_X_LSB 0x0b
> > +#define RES_STA_FIFO_Y_MSB 0x0c
> > +#define RES_STA_FIFO_Y_LSB 0x0d
> > +#define RES_STA_FIFO_PRES_MSB 0x0e
> > +#define RES_STA_FIFO_PRES_LSB 0x0f
> > +#define RES_STA_UART_BRATE_MSB 0x10
> > +#define RES_STA_UART_BRATE_MID 0x11
> > +#define RES_STA_UART_BRATE_LSB 0x12
> > +#define RES_STA_DEV_IDEN 0x13
> > +#define RES_STA_SLIDE_DISPLACE 0x14
> > +#define RES_STA_ROTATE_ANGLE 0x15
> > +
> > +/* Resistive touch configuration registers */
> > +#define CR_CON_SYSTEM 0x40
> > +#define CR_CON_TRIG_EVENT 0x41
> > +#define CR_CON_FIFO_SETUP 0x42
> > +#define CR_CON_SAMPLING_RATE 0x43
> > +#define CR_CON_X_DELAY_MSB 0x44
> > +#define CR_CON_X_DELAY_LSB 0x45
> > +#define CR_CON_Y_DELAY_MSB 0x46
> > +#define CR_CON_Y_DELAY_LSB 0x47
> > +#define CR_CON_Z_DELAY_MSB 0x48
> > +#define CR_CON_Z_DELAY_LSB 0x49
> > +#define CR_CON_DIS_HOR_MSB 0x4a
> > +#define CR_CON_DIS_HOR_LSB 0x4b
> > +#define CR_CON_DIS_VER_MSB 0x4c
> > +#define CR_CON_DIS_VER_LSB 0x4d
> > +#define CR_CON_SLIDE_STEPS 0x4e
> > +
> > +#define RTST_EVENT BIT(7)
> > +#define RTS2T_EVENT BIT(6)
> > +#define RTSZ_EVENT BIT(5)
> > +#define RTSR_EVENT BIT(4)
> > +#define RTSS_EVENT BIT(3)
> > +#define RTSF_EVENT BIT(2)
> > +#define RTSRDY_EVENT BIT(0)
> > +
> > +#define RTSSD_MASK BIT(2)
> > +#define RTSSD_H_NEG BIT(2)
> > +#define RTSSD_V_POS BIT(3)
> > +#define RTSSD_V_NEG BIT(4)
> > +
> > +#define RTSRD_MASK BIT(4)
> > +#define RTSRD_COUNTER_CLK_WISE BIT(4)
> > +
> > +#define RTSZD_MASK BIT(5)
> > +#define RTSZD_ZOOM_OUT BIT(5)
> > +
> > +#define CRTOUCH_MAX_FINGER 2
> > +#define CRTOUCH_MAX_AREA 0xfff
> > +#define CRTOUCH_MAX_X 0x01df
> > +#define CRTOUCH_MAX_Y 0x010f
> > +
> > +struct crtouch_ts_data {
> > + struct i2c_client *client;
> > + struct input_dev *input_dev;
> > +};
> > +
> > +static u8 crtouch_read_reg(struct i2c_client *client, int addr)
> > +{
> > + return i2c_smbus_read_byte_data(client, addr);
> > +}
> > +
> > +static int crtouch_write_reg(struct i2c_client *client, int addr, int
> data)
> > +{
> > + return i2c_smbus_write_byte_data(client, addr, data);
> > +}
> > +
> > +static void calibration_pointer(u16 *x_orig, u16 *y_orig)
> > +{
> > + u16 x, y;
> > +
> > + x = CRTOUCH_MAX_X - *x_orig;
> > + *x_orig = x;
> > +
> > + y = CRTOUCH_MAX_Y - *y_orig;
> > + *y_orig = y;
> > +}
> > +
> > +static irqreturn_t crtouch_ts_interrupt(int irq, void *dev_id)
> > +{
> > + struct crtouch_ts_data *data = dev_id;
> > + struct i2c_client *client = data->client;
> > + u8 status1;
> > + u16 valuep, valuex, valuey;
> > +
> > + status1 = crtouch_read_reg(client, RES_STA_STATUS1);
> > +
> > + /* For single touch */
> > + if (status1 & RTST_EVENT) {
> > + valuep = crtouch_read_reg(client, RES_STA_PRES_MSB);
> > + valuep = ((valuep << 8) |
> > + crtouch_read_reg(client, RES_STA_RRES_LSB));
>
> Is it possible to read 2 bytes at once?
>
> > + valuex = crtouch_read_reg(client, RES_STA_X_MSB);
> > + valuex = ((valuex << 8) |
> > + crtouch_read_reg(client, RES_STA_X_LSB));
> > + valuey = crtouch_read_reg(client, RES_STA_Y_MSB);
> > + valuey = ((valuey << 8) |
> > + crtouch_read_reg(client, RES_STA_Y_LSB));
> > + calibration_pointer(&valuex, &valuey);
>
> I'd do conversion inline - it is clearer what is going on.
>
> > + input_report_key(data->input_dev, BTN_TOUCH, 1);
> > + input_report_abs(data->input_dev, ABS_X, valuex);
> > + input_report_abs(data->input_dev, ABS_Y, valuey);
> > + input_report_abs(data->input_dev, ABS_PRESSURE, valuep);
> > + input_sync(data->input_dev);
> > + } else {
> > + input_report_abs(data->input_dev, ABS_PRESSURE, 0);
> > + input_event(data->input_dev, EV_KEY, BTN_TOUCH, 0);
> > + input_sync(data->input_dev);
> > + }
>
> input_sync() can go here.
>
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static void crtouch_ts_reg_init(struct crtouch_ts_data *data)
> > +{
> > + struct i2c_client *client = data->client;
> > +
> > + crtouch_write_reg(client, CR_CON_SYSTEM, 0x9c);
> > + crtouch_write_reg(client, CR_CON_TRIG_EVENT, 0xf9);
> > + crtouch_write_reg(client, CR_CON_FIFO_SETUP, 0x1f);
> > + crtouch_write_reg(client, CR_CON_SAMPLING_RATE, 0x08);
> > + crtouch_write_reg(client, CR_CON_DIS_HOR_MSB, 0x01);
> > + crtouch_write_reg(client, CR_CON_DIS_HOR_LSB, 0xdf);
> > + crtouch_write_reg(client, CR_CON_DIS_VER_MSB, 0x01);
> > + crtouch_write_reg(client, CR_CON_DIS_VER_LSB, 0x0f);
>
> Should we fetch any of this data from DTS? I assume CR_CON_DIS_HOR/VER
> is resolution? Or not?
>
Yes, the HOR/VER info can at least be fetched from DTS. I will fix as part
of V2 patchset.
>
> Also, why no error handling?
>
> > +}
> > +
> > +static int crtouch_ts_probe(struct i2c_client *client,
> > + const struct i2c_device_id *id)
> > +{
> > + struct crtouch_ts_data *data;
> > + struct input_dev *input_dev;
> > + int error = -1, irq_gpio;
> > +
> > + dev_info(&client->dev, "Freescale CRTOUCH driver\n");
>
> Please drop this.
>
> > +
> > + data = kzalloc(sizeof(*data), GFP_KERNEL);
> > + input_dev = input_allocate_device();
>
> Please use devm* and you will be able to get rid of crtouch_ts_remove().
>
> > + if (!data || !input_dev) {
> > + dev_err(&client->dev, "Failed to allocate memory\n");
> > + error = -ENOMEM;
> > + goto err_free_mem;
> > + }
> > +
> > + data->client = client;
> > + data->input_dev = input_dev;
> > +
> > + input_dev->name = "crtouch_ts";
> > + input_dev->id.bustype = BUS_I2C;
> > + input_dev->dev.parent = &client->dev;
> > +
> > + /* For single touch */
> > + __set_bit(EV_KEY, input_dev->evbit);
> > + __set_bit(BTN_TOUCH, input_dev->keybit);
> > + __set_bit(EV_ABS, input_dev->evbit);
> > + __set_bit(ABS_X, input_dev->absbit);
> > + __set_bit(ABS_Y, input_dev->absbit);
> > + __set_bit(ABS_PRESSURE, input_dev->absbit);
> > +
> > + input_set_abs_params(input_dev, ABS_X, 0, CRTOUCH_MAX_X, 0, 0);
> > + input_set_abs_params(input_dev, ABS_Y, 0, CRTOUCH_MAX_Y, 0, 0);
> > + input_set_abs_params(input_dev, ABS_PRESSURE, 0,
> > + CRTOUCH_MAX_AREA, 0, 0);
> > +
> > + input_set_drvdata(input_dev, data);
> > +
> > + crtouch_ts_reg_init(data);
> > +
> > + irq_gpio = of_get_named_gpio(client->dev.of_node, "irq-gpio", 0);
> > + if (!gpio_is_valid(irq_gpio))
> > + goto err_free_mem;
> > +
> > + error = gpio_request_one(irq_gpio, GPIOF_IN, "TS_IRQ");
> > + if (error) {
> > + dev_err(&client->dev, "Failed to request gpio\n");
> > + goto err_free_mem;
> > + }
> > +
> > + error = request_threaded_irq(gpio_to_irq(irq_gpio), NULL,
> > + crtouch_ts_interrupt,
> > + IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
> > + "crtouch_ts", data);
>
> As i mentioned above replace everything starting with of_get_named_gpio
> with:
>
> error = devm_request_threaded_irq(&cleint->dev, client->irq,
> NULL, crtouch_ts_interrupt,
> IRQF_ONESHOT,
> "crtouch_ts", data);
>
> > +
> > + if (error) {
> > + dev_err(&client->dev, "Failed to register interrupt\n");
> > + goto err_free_mem;
> > + }
> > +
> > + error = input_register_device(data->input_dev);
> > + if (error)
> > + goto err_free_irq;
> > +
> > + i2c_set_clientdata(client, data);
> > + return 0;
> > +
> > +err_free_irq:
> > + free_irq(client->irq, data);
> > +err_free_mem:
> > + input_free_device(input_dev);
> > + kfree(data);
> > + return error;
> > +}
> > +
> > +static int crtouch_ts_remove(struct i2c_client *client)
> > +{
> > + struct crtouch_ts_data *data = i2c_get_clientdata(client);
> > +
> > + free_irq(client->irq, data);
> > + input_unregister_device(data->input_dev);
> > + kfree(data);
>
> With devm it can all be dropped.
>
> > +
> > + return 0;
> > +}
> > +
> > +static const struct i2c_device_id crtouch_ts_id[] = {
> > + {"crtouch_ts", 0},
> > + { }
> > +};
> > +MODULE_DEVICE_TABLE(i2c, crtouch_ts_id);
> > +
> > +static const struct of_device_id crtouch_ts_dt_ids[] = {
> > + { .compatible = "fsl,crtouch_ts", },
> > + { /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, crtouch_ts_dt_ids);
> > +
> > +static struct i2c_driver crtouch_ts_i2c_driver = {
> > + .driver = {
> > + .name = "crtouch_ts",
> > + .owner = THIS_MODULE,
>
> No need to set owner.
>
> > + .of_match_table = crtouch_ts_dt_ids,
>
> .of_match_table = of_match_ptr(crtouch_ts_dt_ids),
>
> Also, no PM methods?
>
>
Well, the main reason for no PM methods is the original driver did not have
PM methods. I can implement sleep/resume methods, and if all is working
well will submit as part of V2.
> > + },
> > + .probe = crtouch_ts_probe,
> > + .remove = crtouch_ts_remove,
> > + .id_table = crtouch_ts_id,
> > +};
> > +
> > +module_i2c_driver(crtouch_ts_i2c_driver);
> > +
> > +MODULE_AUTHOR("Alison Wang <b18965 at freescale.com>");
> > +MODULE_DESCRIPTION("Touchscreen driver for Freescale CRTOUCH");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.7.4
> >
>
> Thanks.
>
> --
> Dmitry
>
--
Tony Felice
Support Engineering Manager
Timesys Corporation
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