Hi Linus,
On Tue, Mar 10, 2020 at 03:28:18PM +0100, Linus Walleij wrote:
> This adds a new driver for the Cypress CY8CTMA140 touchscreen.
>
> This driver is inspired by out-of-tree code for the Samsung
> GT-S7710 mobile phone.
>
> I have tried to compare the structure and behaviour of this
> touchscreen to the existing CYTTSP and CYTTSP4 generics and
> it seems pretty different. It is also different in character
> from the cy8ctmg110_ts.c. It appears to rather be vaguely
> related to the Melfas MMS114 driver, yet distinctly
> different.
>
> Cc: Ferruh Yigit <fery@xxxxxxxxxxx>
> Cc: Henrik Rydberg <rydberg@xxxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> MAINTAINERS | 6 +
> drivers/input/touchscreen/Kconfig | 13 +
> drivers/input/touchscreen/Makefile | 1 +
> drivers/input/touchscreen/cy8ctma140.c | 380 +++++++++++++++++++++++++
> 4 files changed, 400 insertions(+)
> create mode 100644 drivers/input/touchscreen/cy8ctma140.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 8e7433d74530..39163de1a082 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -4628,6 +4628,12 @@ T: git git://linuxtv.org/anttip/media_tree.git
> S: Maintained
> F: drivers/media/common/cypress_firmware*
>
> +CYPRESS CY8CTMA140 TOUCHSCREEN DRIVER
> +M: Linus Walleij <linus.walleij@xxxxxxxxxx>
> +L: linux-input@xxxxxxxxxxxxxxx
> +S: Maintained
> +F: drivers/input/touchscreen/cy8ctma140.c
> +
> CYTTSP TOUCHSCREEN DRIVER
> M: Ferruh Yigit <fery@xxxxxxxxxxx>
> L: linux-input@xxxxxxxxxxxxxxx
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index c071f7c407b6..279b96d1761a 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -214,6 +214,19 @@ config TOUCHSCREEN_CY8CTMG110
> To compile this driver as a module, choose M here: the
> module will be called cy8ctmg110_ts.
>
> +config TOUCHSCREEN_CY8CTMA140
> + tristate "cy8ctma140 touchscreen"
> + depends on I2C
> + depends on GPIOLIB || COMPILE_TEST
> + help
> + Say Y here if you have a Cypress CY8CTMA140 capacitive
> + touchscreen also just known as "TMA140"
> +
> + If unsure, say N.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called cy8ctma140.
> +
> config TOUCHSCREEN_CYTTSP_CORE
> tristate "Cypress TTSP touchscreen"
> help
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 94c6162409b3..006444c8f87b 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -23,6 +23,7 @@ obj-$(CONFIG_TOUCHSCREEN_BU21029) += bu21029_ts.o
> obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8318) += chipone_icn8318.o
> obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8505) += chipone_icn8505.o
> obj-$(CONFIG_TOUCHSCREEN_CY8CTMG110) += cy8ctmg110_ts.o
> +obj-$(CONFIG_TOUCHSCREEN_CY8CTMA140) += cy8ctma140.o
> obj-$(CONFIG_TOUCHSCREEN_CYTTSP_CORE) += cyttsp_core.o
> obj-$(CONFIG_TOUCHSCREEN_CYTTSP_I2C) += cyttsp_i2c.o cyttsp_i2c_common.o
> obj-$(CONFIG_TOUCHSCREEN_CYTTSP_SPI) += cyttsp_spi.o
> diff --git a/drivers/input/touchscreen/cy8ctma140.c b/drivers/input/touchscreen/cy8ctma140.c
> new file mode 100644
> index 000000000000..fb79f4251122
> --- /dev/null
> +++ b/drivers/input/touchscreen/cy8ctma140.c
> @@ -0,0 +1,380 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Driver for Cypress CY8CTMA140 (TMA140) touchscreen
> + * (C) 2020 Linus Walleij <linus.walleij@xxxxxxxxxx>
> + * (C) 2007 Cypress
> + * (C) 2007 Google, Inc.
> + *
> + * Inspired by the tma140_skomer.c driver in the Samsung GT-S7710 code
> + * drop. The GT-S7710 is codenamed "Skomer", the code also indicates
> + * that the same touchscreen was used in a product called "Lucas".
> + *
> + * The code drop for GT-S7710 also contains a firmware downloader and
> + * 15 (!) versions of the firmware drop from Cypress. But here we assume
> + * the firmware got downloaded to the touchscreen flash successfully and
> + * just use it to read the fingers. The shipped vendor driver does the
> + * same.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/input.h>
> +#include <linux/input/touchscreen.h>
> +#include <linux/input/mt.h>
> +#include <linux/slab.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/i2c.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/delay.h>
> +
> +/* Used for driver name etc */
> +#define CY8CTMA140_NAME "cy8ctma140"
> +
> +/*
> + * The datasheet claims the device supports 4 fingers but the firmware
> + * I've seen certainly only supports 2 fingers.
> + */
> +#define CY8CTMA140_MAX_FINGERS 2
> +#define CY8CTMA140_GET_FINGERS 0x00
> +#define CY8CTMA140_GET_FW_INFO 0x19
> +
> +struct cy8ctma140 {
> + struct input_dev *input;
> + struct touchscreen_properties props;
> + struct device *dev;
> + struct i2c_client *client;
> + struct regulator *vcpin;
> + struct regulator *vdd;
> + struct gpio_desc *irq;
> +};
> +
> +static irqreturn_t cy8ctma140_irq_thread(int irq, void *d)
> +{
> + struct cy8ctma140 *ts = d;
> + u8 msgbuf0[1];
> + u8 buf[31];
> + struct i2c_msg msg[2] = {
Drop explicit size?
> + {
> + .addr = ts->client->addr,
> + .flags = 0,
> + .len = 1,
> + .buf = msgbuf0,
> + }, {
> + .addr = ts->client->addr,
> + .flags = I2C_M_RD,
> + .len = sizeof(buf),
> + .buf = buf,
> + },
> + };
> + u8 fingers;
> + u16 f1x, f1y, f1z;
> + u16 f2x, f2y, f2z;
> + int ret;
> + int slots[CY8CTMA140_MAX_FINGERS];
> + struct input_mt_pos pos[CY8CTMA140_MAX_FINGERS];
> +
> + msgbuf0[0] = CY8CTMA140_GET_FINGERS;
> + ret = __i2c_transfer(ts->client->adapter, msg, 2);
ARRAY_SIZE() instead of 2 here and below.
Who is taking the adapter lock so that __i2c_transfer() can be used?
Why can't normal i2c_transfer() be used here?
> + if (ret < 0) {
> + dev_err(ts->dev, "error reading message\n");
> + goto evt_out;
> + }
> + if (ret != 2) {
> + dev_err(ts->dev, "wrong number of messages\n");
> + goto evt_out;
> + }
> + if (buf[1] & 0x20) {
> + dev_info(ts->dev, "invalid event\n");
> + goto evt_out;
> + }
> +
> + f1x = buf[3] << 8 | buf[4];
get_unaligned_be16() here and below.
> + f1y = buf[5] << 8 | buf[6];
> + f1z = buf[7];
> +
> + f2x = buf[9] << 8 | buf[10];
> + f2y = buf[11] << 8 | buf[12];
> + f2z = buf[13];
> +
> + fingers = buf[2] & 0x0f;
> + if (fingers == 0) {
> + dev_info(ts->dev, "no fingers\n");
> + goto evt_out;
> + }
> +
> + input_mt_assign_slots(ts->input, slots, pos, fingers, 0);
> +
> + /*
> + * When just handling two fingers this code is simple and we do not
> + * need a loop increasing the complexity. If you need to modify
> + * this driver for some firmware handling more than 2 fingers,
> + * this is where you put in an array of coordinated and a loop
> + * instead.
> + */
> + if (fingers >= 1) {
> + dev_dbg(ts->dev, "%d fingers: finger 1 ID: %02x (%d, %d, %d)\n",
> + fingers, buf[8] >> 4, f1x, f1y, f1z);
> + input_mt_slot(ts->input, slots[0]);
> + input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
> + input_report_abs(ts->input, ABS_MT_POSITION_X, f1x);
> + input_report_abs(ts->input, ABS_MT_POSITION_Y, f1y);
> + input_report_abs(ts->input, ABS_MT_PRESSURE, f1z);
> + }
> + if (fingers >= 2) {
> + dev_dbg(ts->dev, "%d fingers: finger 2 ID %02x (%d, %d, %d)\n",
> + fingers, buf[8] & 0x0f, f2x, f2y, f2z);
> + input_mt_slot(ts->input, slots[1]);
> + input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
> + input_report_abs(ts->input, ABS_MT_POSITION_X, f2x);
> + input_report_abs(ts->input, ABS_MT_POSITION_Y, f2y);
> + input_report_abs(ts->input, ABS_MT_PRESSURE, f2z);
Please use touchscreen_set_mt_pos()/touchscreen_report_pos() so that we
can support common transformation device properties from
of_touchscreen.c
> + }
> + if (fingers > 2)
> + dev_err(ts->dev, "%d fingers - unsupported!\n", fingers);
> +
> + input_mt_sync_frame(ts->input);
> + input_sync(ts->input);
> +
> +evt_out:
> + return IRQ_HANDLED;
> +}
> +
> +static int cy8ctma140_init(struct cy8ctma140 *ts)
> +{
> + u8 addr[1];
> + u8 buf[5];
> + int ret;
> +
> + addr[0] = CY8CTMA140_GET_FW_INFO;
> + ret = i2c_master_send(ts->client, addr, 1);
> + if (ret < 0) {
> + dev_err(ts->dev, "error sending FW info message\n");
> + return ret;
> + }
> + ret = i2c_master_recv(ts->client, buf, 5);
> + if (ret < 0) {
> + dev_err(ts->dev, "error recieveing FW info message\n");
> + return ret;
> + }
> + if (ret != 5) {
> + dev_err(ts->dev, "got only %d bytes\n", ret);
> + return -EIO;
> + }
> +
> + dev_info(ts->dev, "vendor %c%c, HW ID %.2d, FW ver %.4d\n",
> + buf[0], buf[1], buf[3], buf[4]);
> + return 0;
> +}
> +
> +static int cy8ctma140_power_up(struct cy8ctma140 *ts)
> +{
> + int ret;
> +
> + ret = regulator_enable(ts->vcpin);
> + if (ret) {
> + dev_err(ts->dev, "failed to enable VCPIN voltage\n");
> + return ret;
> + }
> + ret = regulator_enable(ts->vdd);
> + if (ret) {
> + dev_err(ts->dev, "failed to enable VDD voltage\n");
> + regulator_disable(ts->vcpin);
> + return ret;
> + }
Use bulk regulator API?
> +
> + msleep(250);
> +
> + return 0;
> +}
> +
> +static void cy8ctma140_power_down(struct cy8ctma140 *ts)
> +{
> + regulator_disable(ts->vdd);
> + regulator_disable(ts->vcpin);
> +}
> +
> +/* Called from the registered devm action */
> +static void cy8ctma140_power_off_action(void *d)
> +{
> + struct cy8ctma140 *ts = d;
> +
> + cy8ctma140_power_down(ts);
> +}
> +
> +static int cy8ctma140_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct cy8ctma140 *ts;
> + struct input_dev *input;
> + struct device *dev = &client->dev;
> + int ret;
> +
> + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> + if (!ts)
> + return -ENOMEM;
> +
> + input = devm_input_allocate_device(dev);
> + if (!input)
> + return -ENOMEM;
> +
> + ts->dev = dev;
> + ts->client = client;
> + ts->input = input;
> +
> + /*
> + * This sets up event max/min capabilities and fuzz.
> + * Some DT properties are compulsory so we do not need
> + * to provide defaults for X/Y max or pressure max.
> + *
> + * We just initialize a very simple MT touchscreen here,
> + * some devices use the capability of this touchscreen to
> + * provide touchkeys, and in that case this needs to be
> + * extended to handle touchkey input.
> + *
> + * The firmware takes care of finger tracking and dropping
> + * invalid ranges.
> + */
> + touchscreen_parse_properties(input, true, &ts->props);
> +
> + ret = input_mt_init_slots(input, CY8CTMA140_MAX_FINGERS,
> + INPUT_MT_DIRECT);
> + if (ret)
> + return ret;
Since this holds and returns error codes, can we call this variable
"error" please?
> +
> + input->name = CY8CTMA140_NAME;
> + input->phys = "inpus/ts";
Umm... If there is not a better physical location string, maybe just
omit it?
> + input->id.bustype = BUS_I2C;
> + input_set_drvdata(input, ts);
> +
> + /* VCPIN is the analog voltage supply */
> + ts->vcpin = devm_regulator_get(dev, "vcpin");
> + if (IS_ERR(ts->vcpin)) {
> + if (PTR_ERR(ts->vcpin) != -EPROBE_DEFER)
> + dev_err(dev, "Failed to get VCPIN regulator %d\n",
> + (int)PTR_ERR(ts->vcpin));
> + return PTR_ERR(ts->vcpin);
> + }
> + /* According to datasheet this should be in the 2.7-3.6 V range */
> + ret = regulator_set_voltage(ts->vcpin, 2700000, 3600000);
> + if (ret) {
> + dev_err(dev, "failed to set VCPIN voltage\n");
> + return ret;
> + }
Shouldn't this already be in DT? We typically do not configure voltage
on various rail unless in very specific circumstances.
> +
> + /*
> + * VDD is the digital voltage supply
> + * since the voltage range of VDD overlaps that of VCPIN,
> + * many designs to just supply both with a single voltage
> + * source of ~3.3 V.
> + */
> + ts->vdd = devm_regulator_get(dev, "vdd");
> + if (IS_ERR(ts->vdd)) {
> + if (PTR_ERR(ts->vdd) != -EPROBE_DEFER)
> + dev_err(dev, "Failed to get VDD regulator %d\n",
> + (int)PTR_ERR(ts->vdd));
> + return PTR_ERR(ts->vdd);
> + }
> + /* According to datasheet this should be in the 1.71-3.6 V range */
> + ret = regulator_set_voltage(ts->vdd, 2700000, 3600000);
> + if (ret) {
> + dev_err(dev, "failed to set VDD voltage\n");
> + return ret;
> + }
> +
> + ret = cy8ctma140_power_up(ts);
> + if (ret)
> + return ret;
> + ret = devm_add_action_or_reset(dev, cy8ctma140_power_off_action, ts);
> + if (ret) {
> + dev_err(dev, "failed to install power off handler\n");
> + return ret;
> + }
> +
> + ret = devm_request_threaded_irq(dev, client->irq, NULL,
> + cy8ctma140_irq_thread,
> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
The trigger (edge, level) should come from DT.
> + CY8CTMA140_NAME, ts);
> + if (ret) {
> + dev_err(dev, "irq %d busy? error %d\n", client->irq, ret);
> + goto err_reg_dis;
> + }
> +
> + ret = cy8ctma140_init(ts);
> + if (ret)
> + return ret;
> +
> + ret = input_register_device(input);
> + if (ret)
> + goto err_reg_dis;
> +
> + i2c_set_clientdata(client, ts);
> +
> + device_init_wakeup(dev, 1);
We should not mark device as wakeup source unconditionally. If there is
"wakeup-source" property in DT, i2c core will do the right thing
automatically. Please drop.
> + return 0;
> +
> +err_reg_dis:
> + cy8ctma140_power_down(ts);
> + return ret;
> +}
> +
> +static int __maybe_unused cy8ctma140_suspend(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct cy8ctma140 *ts = i2c_get_clientdata(client);
> +
> + if (device_may_wakeup(&client->dev))
> + enable_irq_wake(client->irq);
No need as i2c core manages wake irq if there is "wakeup-source"
property. So it should read:
if (!device_may_wakeup(&client->dev))
cy8ctma140_power_down(ts);
> + else
> + cy8ctma140_power_down(ts);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused cy8ctma140_resume(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct cy8ctma140 *ts = i2c_get_clientdata(client);
> + int ret;
> +
> + if (device_may_wakeup(&client->dev)) {
> + disable_irq_wake(client->irq);
> + } else {
> + ret = cy8ctma140_power_up(ts);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(cy8ctma140_pm, cy8ctma140_suspend, cy8ctma140_resume);
> +
> +static const struct i2c_device_id cy8ctma140_idtable[] = {
> + { CY8CTMA140_NAME, 0 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, cy8ctma140_idtable);
> +
> +static const struct of_device_id cy8ctma140_of_match[] = {
> + {
> + .compatible = "cypress,cy8ctma140",
> + },
> +};
> +MODULE_DEVICE_TABLE(of, cy8ctma140_of_match);
> +
> +static struct i2c_driver cy8ctma140_driver = {
> + .driver = {
> + .name = CY8CTMA140_NAME,
> + .pm = &cy8ctma140_pm,
> + .of_match_table = cy8ctma140_of_match,
> + },
> + .id_table = cy8ctma140_idtable,
> + .probe = cy8ctma140_probe,
> +};
> +module_i2c_driver(cy8ctma140_driver);
> +
> +MODULE_AUTHOR("Linus Walleij <linus.walleij@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("CY8CTMA140 TouchScreen Driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.21.1
>
Thanks.
--
Dmitry
