Re: [PATCH v3 3/4] input: touchscreen: add I2C support for Goodix Berlin Touchscreen IC

[Neil Armstrong]

Hi Jeff,

On 25/06/2023 21:17, Jeff LaBundy wrote:
> Hi Neil,
>
> On Thu, Jun 22, 2023 at 04:29:01PM +0200, Neil Armstrong wrote:
> > Add initial support for the new Goodix "Berlin" touchscreen ICs
> > over the I2C interface.
> >
> > This initial driver is derived from the Goodix goodix_ts_berlin
> > available at [1] and [2] and only supports the GT9916 IC
> > present on the Qualcomm SM8550 MTP & QRD touch panel.
> >
> > The current implementation only supports BerlinD, aka GT9916.
> >
> > [1] https://github.com/goodix/goodix_ts_berlin
> > [2] https://git.codelinaro.org/clo/la/platform/vendor/opensource/touch-drivers
> >
> > Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> > ---
>
> Just one comment below, then feel free to add:
>
> Reviewed-by: Jeff LaBundy <jeff@xxxxxxxxxxx>
>
> >   drivers/input/touchscreen/Kconfig             | 14 ++++++
> >   drivers/input/touchscreen/Makefile            |  1 +
> >   drivers/input/touchscreen/goodix_berlin_i2c.c | 69 +++++++++++++++++++++++++++
> >   3 files changed, 84 insertions(+)
> >
> > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> > index 1a6f6f6da991..5e21cca6025d 100644
> > --- a/drivers/input/touchscreen/Kconfig
> > +++ b/drivers/input/touchscreen/Kconfig
> > @@ -421,6 +421,20 @@ config TOUCHSCREEN_GOODIX_BERLIN_CORE
> >   	depends on REGMAP
> >   	tristate
> >   
> > +config TOUCHSCREEN_GOODIX_BERLIN_I2C
> > +	tristate "Goodix Berlin I2C touchscreen"
> > +	depends on I2C
> > +	depends on REGMAP_I2C
>
> select REGMAP_I2C
>
> (keep "depends on I2C")

Good point,

Thanks,
Neil

> > +	select TOUCHSCREEN_GOODIX_BERLIN_CORE
> > +	help
> > +	  Say Y here if you have a Goodix Berlin IC connected to
> > +	  your system via I2C.
> > +
> > +	  If unsure, say N.
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called goodix_berlin_i2c.
> > +
> >   config TOUCHSCREEN_HIDEEP
> >   	tristate "HiDeep Touch IC"
> >   	depends on I2C
> > diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> > index 29cdb042e104..921a2da0c2be 100644
> > --- a/drivers/input/touchscreen/Makefile
> > +++ b/drivers/input/touchscreen/Makefile
> > @@ -48,6 +48,7 @@ obj-$(CONFIG_TOUCHSCREEN_EXC3000)	+= exc3000.o
> >   obj-$(CONFIG_TOUCHSCREEN_FUJITSU)	+= fujitsu_ts.o
> >   obj-$(CONFIG_TOUCHSCREEN_GOODIX)	+= goodix_ts.o
> >   obj-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_CORE)	+= goodix_berlin_core.o
> > +obj-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_I2C)	+= goodix_berlin_i2c.o
> >   obj-$(CONFIG_TOUCHSCREEN_HIDEEP)	+= hideep.o
> >   obj-$(CONFIG_TOUCHSCREEN_HYNITRON_CSTXXX)	+= hynitron_cstxxx.o
> >   obj-$(CONFIG_TOUCHSCREEN_ILI210X)	+= ili210x.o
> > diff --git a/drivers/input/touchscreen/goodix_berlin_i2c.c b/drivers/input/touchscreen/goodix_berlin_i2c.c
> > new file mode 100644
> > index 000000000000..6407b2258eb1
> > --- /dev/null
> > +++ b/drivers/input/touchscreen/goodix_berlin_i2c.c
> > @@ -0,0 +1,69 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Goodix Berlin Touchscreen Driver
> > + *
> > + * Copyright (C) 2020 - 2021 Goodix, Inc.
> > + * Copyright (C) 2023 Linaro Ltd.
> > + *
> > + * Based on goodix_ts_berlin driver.
> > + */
> > +#include <linux/i2c.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/regmap.h>
> > +
> > +#include "goodix_berlin.h"
> > +
> > +#define I2C_MAX_TRANSFER_SIZE		256
> > +
> > +static const struct regmap_config goodix_berlin_i2c_regmap_conf = {
> > +	.reg_bits = 32,
> > +	.val_bits = 8,
> > +	.max_raw_read = I2C_MAX_TRANSFER_SIZE,
> > +	.max_raw_write = I2C_MAX_TRANSFER_SIZE,
> > +};
> > +
> > +/* vendor & product left unassigned here, should probably be updated from fw info */
> > +static const struct input_id goodix_berlin_i2c_input_id = {
> > +	.bustype = BUS_I2C,
> > +};
> > +
> > +static int goodix_berlin_i2c_probe(struct i2c_client *client)
> > +{
> > +	struct regmap *regmap;
> > +
> > +	regmap = devm_regmap_init_i2c(client, &goodix_berlin_i2c_regmap_conf);
> > +	if (IS_ERR(regmap))
> > +		return PTR_ERR(regmap);
> > +
> > +	return goodix_berlin_probe(&client->dev, client->irq,
> > +				   &goodix_berlin_i2c_input_id, regmap);
> > +}
> > +
> > +static const struct i2c_device_id goodix_berlin_i2c_id[] = {
> > +	{ "gt9916", 0 },
> > +	{ }
> > +};
> > +
> > +MODULE_DEVICE_TABLE(i2c, goodix_berlin_i2c_id);
> > +
> > +static const struct of_device_id goodix_berlin_i2c_of_match[] = {
> > +	{ .compatible = "goodix,gt9916", },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(of, goodix_berlin_i2c_of_match);
> > +
> > +static struct i2c_driver goodix_berlin_i2c_driver = {
> > +	.driver = {
> > +		.name = "goodix-berlin-i2c",
> > +		.of_match_table = goodix_berlin_i2c_of_match,
> > +		.pm = pm_sleep_ptr(&goodix_berlin_pm_ops),
> > +	},
> > +	.probe = goodix_berlin_i2c_probe,
> > +	.id_table = goodix_berlin_i2c_id,
> > +};
> > +module_i2c_driver(goodix_berlin_i2c_driver);
> > +
> > +MODULE_LICENSE("GPL");
> > +MODULE_DESCRIPTION("Goodix Berlin I2C Touchscreen driver");
> > +MODULE_AUTHOR("Neil Armstrong <neil.armstrong@xxxxxxxxxx>");
> >
> > --
> > 2.34.1
>
> Kind regards,
> Jeff LaBundy