Goodix i2c-hid touchscreens are mostly i2c-hid compliant but have some special power sequencing requirements, including the need to drive a reset line during the sequencing.
Let's use the new rejiggering of i2c-hid to support this with a thin wrapper driver to support the first Goodix i2c-hid touchscreen: GT7375P Signed-off-by: Douglas Anderson <diand...@chromium.org> --- Changes in v6: - Suspend/resume are no longer exported from the core. Changes in v5: - i2chid_subclass_data => i2chid_ops. - power_up_device => power_up (same with power_down). - subclass => ops. Changes in v4: - Totally redid based on the new subclass system. Changes in v3: - Rework to use subclassing. drivers/hid/i2c-hid/Kconfig | 19 +++- drivers/hid/i2c-hid/Makefile | 1 + drivers/hid/i2c-hid/i2c-hid-of-goodix.c | 116 ++++++++++++++++++++++++ 3 files changed, 134 insertions(+), 2 deletions(-) create mode 100644 drivers/hid/i2c-hid/i2c-hid-of-goodix.c diff --git a/drivers/hid/i2c-hid/Kconfig b/drivers/hid/i2c-hid/Kconfig index 819b7521c182..a16c6a69680b 100644 --- a/drivers/hid/i2c-hid/Kconfig +++ b/drivers/hid/i2c-hid/Kconfig @@ -32,10 +32,25 @@ config I2C_HID_OF will be called i2c-hid-of. It will also build/depend on the module i2c-hid. +config I2C_HID_OF_GOODIX + tristate "Driver for Goodix hid-i2c based devices on OF systems" + default n + depends on I2C && INPUT && OF + help + Say Y here if you want support for Goodix i2c devices that use + the i2c-hid protocol on Open Firmware (Device Tree)-based + systems. + + If unsure, say N. + + This support is also available as a module. If so, the module + will be called i2c-hid-of-goodix. It will also build/depend on + the module i2c-hid. + endmenu config I2C_HID_CORE tristate - default y if I2C_HID_ACPI=y || I2C_HID_OF=y - default m if I2C_HID_ACPI=m || I2C_HID_OF=m + default y if I2C_HID_ACPI=y || I2C_HID_OF=y || I2C_HID_OF_GOODIX=y + default m if I2C_HID_ACPI=m || I2C_HID_OF=m || I2C_HID_OF_GOODIX=m select HID diff --git a/drivers/hid/i2c-hid/Makefile b/drivers/hid/i2c-hid/Makefile index 9b4a73446841..302545a771f3 100644 --- a/drivers/hid/i2c-hid/Makefile +++ b/drivers/hid/i2c-hid/Makefile @@ -10,3 +10,4 @@ i2c-hid-$(CONFIG_DMI) += i2c-hid-dmi-quirks.o obj-$(CONFIG_I2C_HID_ACPI) += i2c-hid-acpi.o obj-$(CONFIG_I2C_HID_OF) += i2c-hid-of.o +obj-$(CONFIG_I2C_HID_OF_GOODIX) += i2c-hid-of-goodix.o diff --git a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c new file mode 100644 index 000000000000..7cc51c25c609 --- /dev/null +++ b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c @@ -0,0 +1,116 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Driver for Goodix touchscreens that use the i2c-hid protocol. + * + * Copyright 2020 Google LLC + */ + +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/gpio/consumer.h> +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/pm.h> +#include <linux/regulator/consumer.h> + +#include "i2c-hid.h" + +struct goodix_i2c_hid_timing_data { + unsigned int post_gpio_reset_delay_ms; + unsigned int post_power_delay_ms; +}; + +struct i2c_hid_of_goodix { + struct i2chid_ops ops; + + struct regulator *vdd; + struct gpio_desc *reset_gpio; + const struct goodix_i2c_hid_timing_data *timings; +}; + +static int goodix_i2c_hid_power_up(struct i2chid_ops *ops) +{ + struct i2c_hid_of_goodix *ihid_goodix = + container_of(ops, struct i2c_hid_of_goodix, ops); + int ret; + + ret = regulator_enable(ihid_goodix->vdd); + if (ret) + return ret; + + if (ihid_goodix->timings->post_power_delay_ms) + msleep(ihid_goodix->timings->post_power_delay_ms); + + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 0); + if (ihid_goodix->timings->post_gpio_reset_delay_ms) + msleep(ihid_goodix->timings->post_gpio_reset_delay_ms); + + return 0; +} + +static void goodix_i2c_hid_power_down(struct i2chid_ops *ops) +{ + struct i2c_hid_of_goodix *ihid_goodix = + container_of(ops, struct i2c_hid_of_goodix, ops); + + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); + regulator_disable(ihid_goodix->vdd); +} + +static int i2c_hid_of_goodix_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct i2c_hid_of_goodix *ihid_goodix; + + ihid_goodix = devm_kzalloc(&client->dev, sizeof(*ihid_goodix), + GFP_KERNEL); + if (!ihid_goodix) + return -ENOMEM; + + ihid_goodix->ops.power_up = goodix_i2c_hid_power_up; + ihid_goodix->ops.power_down = goodix_i2c_hid_power_down; + + /* Start out with reset asserted */ + ihid_goodix->reset_gpio = + devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH); + if (IS_ERR(ihid_goodix->reset_gpio)) + return PTR_ERR(ihid_goodix->reset_gpio); + + ihid_goodix->vdd = devm_regulator_get(&client->dev, "vdd"); + if (IS_ERR(ihid_goodix->vdd)) + return PTR_ERR(ihid_goodix->vdd); + + ihid_goodix->timings = device_get_match_data(&client->dev); + + return i2c_hid_core_probe(client, &ihid_goodix->ops, 0x0001); +} + +static const struct goodix_i2c_hid_timing_data goodix_gt7375p_timing_data = { + .post_power_delay_ms = 10, + .post_gpio_reset_delay_ms = 120, +}; + +static const struct of_device_id goodix_i2c_hid_of_match[] = { + { .compatible = "goodix,gt7375p", .data = &goodix_gt7375p_timing_data }, + { } +}; +MODULE_DEVICE_TABLE(of, goodix_i2c_hid_of_match); + +static struct i2c_driver goodix_i2c_hid_ts_driver = { + .driver = { + .name = "i2c_hid_of_goodix", + .pm = &i2c_hid_core_pm, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + .of_match_table = of_match_ptr(goodix_i2c_hid_of_match), + }, + .probe = i2c_hid_of_goodix_probe, + .remove = i2c_hid_core_remove, + .shutdown = i2c_hid_core_shutdown, +}; +module_i2c_driver(goodix_i2c_hid_ts_driver); + +MODULE_AUTHOR("Douglas Anderson <diand...@chromium.org>"); +MODULE_DESCRIPTION("Goodix i2c-hid touchscreen driver"); +MODULE_LICENSE("GPL v2"); -- 2.29.2.222.g5d2a92d10f8-goog