[RFC,4/4] input: touchscreen: add SPI support for Goodix Berlin Touchscreen IC
Commit Message
Add initial support for the new Goodix "Berlin" touchscreen ICs
over the SPI interface.
The driver doesn't use the regmap_spi code since the SPI messages
needs to be prefixed, thus this custom regmap code.
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@linaro.org>
---
drivers/input/touchscreen/Kconfig | 14 ++
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/goodix_berlin_spi.c | 183 ++++++++++++++++++++++++++
3 files changed, 198 insertions(+)
Comments
Hi Neil,
On Tue, Jun 06, 2023 at 04:31:59PM +0200, Neil Armstrong wrote:
> Add initial support for the new Goodix "Berlin" touchscreen ICs
> over the SPI interface.
>
> The driver doesn't use the regmap_spi code since the SPI messages
> needs to be prefixed, thus this custom regmap code.
>
> 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@linaro.org>
> ---
> drivers/input/touchscreen/Kconfig | 14 ++
> drivers/input/touchscreen/Makefile | 1 +
> drivers/input/touchscreen/goodix_berlin_spi.c | 183 ++++++++++++++++++++++++++
> 3 files changed, 198 insertions(+)
>
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index da6d5d75c42d..ffe0c0a4cd15 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -435,6 +435,20 @@ config TOUCHSCREEN_GOODIX_BERLIN_I2C
> To compile this driver as a module, choose M here: the
> module will be called goodix_berlin_i2c.
>
> +config TOUCHSCREEN_GOODIX_BERLIN_SPI
> + tristate "Goodix Berlin SPI touchscreen"
> + depends on SPI_MASTER
> + depends on REGMAP
As TOUCHSCREEN_GOODIX_BERLIN_CORE already depends on REGMAP; is this
line necessary?
I was about to ask why not to select REGMAP_SPI; thank you for the
additional information in the commit message.
> + select TOUCHSCREEN_GOODIX_BERLIN_CORE
> + help
> + Say Y here if you have the a touchscreen connected to your
> + system using the Goodix Berlin IC connection via SPI.
Same comment here with regard to diction.
> +
> + If unsure, say N.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called goodix_berlin_spi.
> +
> config TOUCHSCREEN_HIDEEP
> tristate "HiDeep Touch IC"
> depends on I2C
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 921a2da0c2be..29524e8a83db 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -49,6 +49,7 @@ 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-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_SPI) += goodix_berlin_spi.o
> obj-$(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_spi.c b/drivers/input/touchscreen/goodix_berlin_spi.c
> new file mode 100644
> index 000000000000..0f4f650fdf3f
> --- /dev/null
> +++ b/drivers/input/touchscreen/goodix_berlin_spi.c
> @@ -0,0 +1,183 @@
> +// 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/kernel.h>
> +#include <linux/module.h>
> +#include <linux/spi/spi.h>
> +#include <linux/regmap.h>
Please alphabetize these to aid readability.
> +#include <asm/unaligned.h>
> +
> +#include "goodix_berlin.h"
> +
> +#define SPI_TRANS_PREFIX_LEN 1
> +#define REGISTER_WIDTH 4
> +#define SPI_READ_DUMMY_LEN 3
> +#define SPI_READ_PREFIX_LEN (SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH + SPI_READ_DUMMY_LEN)
> +#define SPI_WRITE_PREFIX_LEN (SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH)
> +
> +#define SPI_WRITE_FLAG 0xF0
> +#define SPI_READ_FLAG 0xF1
> +
> +static int goodix_berlin_spi_read(void *context, const void *reg_buf,
> + size_t reg_size, void *val_buf,
> + size_t val_size)
> +{
> + struct spi_device *spi = context;
> + struct spi_transfer xfers;
> + struct spi_message spi_msg;
> + const u32 *reg = reg_buf; /* reg is stored as native u32 at start of buffer */
> + u8 *buf = NULL;
> + int ret = 0;
No need to initialize these, only to forcibly assign them later.
> +
> + if (reg_size != REGISTER_WIDTH)
> + return -EINVAL;
> +
> + buf = kzalloc(SPI_READ_PREFIX_LEN + val_size, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + spi_message_init(&spi_msg);
> + memset(&xfers, 0, sizeof(xfers));
> +
> + /* buffer format: 0xF1 + addr(4bytes) + dummy(3bytes) + data */
> + buf[0] = SPI_READ_FLAG;
> + put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
> + memset(buf + SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH, 0xff,
> + SPI_READ_DUMMY_LEN);
> +
> + xfers.tx_buf = buf;
> + xfers.rx_buf = buf;
> + xfers.len = SPI_READ_PREFIX_LEN + val_size;
> + xfers.cs_change = 0;
> + spi_message_add_tail(&xfers, &spi_msg);
> +
> + ret = spi_sync(spi, &spi_msg);
> + if (ret < 0) {
> + dev_err(&spi->dev, "transfer error:%d", ret);
> + goto exit;
> + }
My comment is purely idiomatic, but this seems cleaner:
ret = ...
if (ret)
dev_err(...);
else
memcpy(...);
kfree(...);
return ret;
> +
> + memcpy(val_buf, buf + SPI_READ_PREFIX_LEN, val_size);
> +exit:
> + kfree(buf);
> + return ret;
> +}
> +
> +static int goodix_berlin_spi_write(void *context, const void *data,
> + size_t count)
> +{
> + unsigned int len = count - REGISTER_WIDTH;
> + struct spi_device *spi = context;
> + struct spi_transfer xfers;
> + struct spi_message spi_msg;
> + const u32 *reg = data; /* reg is stored as native u32 at start of buffer */
> + u8 *buf = NULL;
> + int ret = 0;
Same comment here with regard to initialization.
> +
> + buf = kzalloc(SPI_WRITE_PREFIX_LEN + len, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + spi_message_init(&spi_msg);
> + memset(&xfers, 0, sizeof(xfers));
> +
> + buf[0] = SPI_WRITE_FLAG;
> + put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
> + memcpy(buf + SPI_WRITE_PREFIX_LEN, data + REGISTER_WIDTH, len);
> +
> + xfers.tx_buf = buf;
> + xfers.len = SPI_WRITE_PREFIX_LEN + len;
> + xfers.cs_change = 0;
> + spi_message_add_tail(&xfers, &spi_msg);
> +
> + ret = spi_sync(spi, &spi_msg);
> + if (ret < 0)
> + dev_err(&spi->dev, "transfer error:%d", ret);
> +
> + kfree(buf);
> + return ret;
> +}
> +
> +static const struct regmap_config goodix_berlin_spi_regmap_conf = {
> + .reg_bits = 32,
> + .val_bits = 8,
> + .read = goodix_berlin_spi_read,
> + .write = goodix_berlin_spi_write,
> +};
> +
> +static const struct input_id goodix_berlin_spi_input_id = {
> + .bustype = BUS_SPI,
> + .vendor = 0x0416,
> + .product = 0x1001,
After having seen these in the I2C counterpart; consider defining them
in goodix_berlin.h.
> +};
> +
> +static int goodix_berlin_spi_probe(struct spi_device *spi)
> +{
> + struct regmap_config *cfg;
regmap_config
> + struct regmap *map;
regmap
(see more examples in MFD where such dual-mode devices are common).
> + size_t max_size;
> + int ret = 0;
> +
> + cfg = devm_kmemdup(&spi->dev, &goodix_berlin_spi_regmap_conf,
> + sizeof(*cfg), GFP_KERNEL);
> + if (!cfg)
> + return -ENOMEM;
> +
> + spi->mode = SPI_MODE_0;
> + spi->bits_per_word = 8;
> + ret = spi_setup(spi);
> + if (ret)
> + return ret;
> +
> + max_size = spi_max_transfer_size(spi);
> + cfg->max_raw_read = max_size - SPI_READ_PREFIX_LEN;
> + cfg->max_raw_write = max_size - SPI_WRITE_PREFIX_LEN;
> +
> + map = devm_regmap_init(&spi->dev, NULL, spi, cfg);
> + if (IS_ERR(map))
> + return PTR_ERR(map);
> +
> + return goodix_berlin_probe(&spi->dev, spi->irq,
> + &goodix_berlin_spi_input_id, map);
> +}
> +
> +static void goodix_berlin_spi_remove(struct spi_device *spi)
> +{
> + goodix_berlin_remove(&spi->dev);
> +}
> +
> +static const struct of_device_id goodix_berlin_spi_of_match[] = {
> + {
> + .compatible = "goodix,gt9916",
> + },
This format is different than its I2C counterpart.
> + { },
Nit: same comment with regards to trailing commas.
> +};
> +MODULE_DEVICE_TABLE(of, goodix_berlin_spi_of_match);
> +
> +static const struct spi_device_id goodix_berlin_spi_ids[] = {
> + { "gt9916" },
> + { },
And here.
> +};
> +MODULE_DEVICE_TABLE(spi, goodix_berlin_spi_ids);
> +
> +static struct spi_driver goodix_berlin_spi_driver = {
> + .driver = {
> + .name = "goodix-berlin-spi",
> + .of_match_table = goodix_berlin_spi_of_match,
> + .pm = pm_sleep_ptr(&goodix_berlin_pm_ops),
> + },
> + .id_table = goodix_berlin_spi_ids,
> + .probe = goodix_berlin_spi_probe,
> + .remove = goodix_berlin_spi_remove,
> +};
> +module_spi_driver(goodix_berlin_spi_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Goodix Berlin SPI Touchscreen driver");
> +MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>");
>
> --
> 2.34.1
>
Kind regards,
Jeff LaBundy
Hi,
On 12/06/2023 05:31, Jeff LaBundy wrote:
> Hi Neil,
>
> On Tue, Jun 06, 2023 at 04:31:59PM +0200, Neil Armstrong wrote:
>> Add initial support for the new Goodix "Berlin" touchscreen ICs
>> over the SPI interface.
>>
>> The driver doesn't use the regmap_spi code since the SPI messages
>> needs to be prefixed, thus this custom regmap code.
>>
>> 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@linaro.org>
>> ---
>> drivers/input/touchscreen/Kconfig | 14 ++
>> drivers/input/touchscreen/Makefile | 1 +
>> drivers/input/touchscreen/goodix_berlin_spi.c | 183 ++++++++++++++++++++++++++
>> 3 files changed, 198 insertions(+)
>>
>> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
>> index da6d5d75c42d..ffe0c0a4cd15 100644
>> --- a/drivers/input/touchscreen/Kconfig
>> +++ b/drivers/input/touchscreen/Kconfig
>> @@ -435,6 +435,20 @@ config TOUCHSCREEN_GOODIX_BERLIN_I2C
>> To compile this driver as a module, choose M here: the
>> module will be called goodix_berlin_i2c.
>>
>> +config TOUCHSCREEN_GOODIX_BERLIN_SPI
>> + tristate "Goodix Berlin SPI touchscreen"
>> + depends on SPI_MASTER
>> + depends on REGMAP
>
> As TOUCHSCREEN_GOODIX_BERLIN_CORE already depends on REGMAP; is this
> line necessary?
>
> I was about to ask why not to select REGMAP_SPI; thank you for the
> additional information in the commit message.
>
>> + select TOUCHSCREEN_GOODIX_BERLIN_CORE
>> + help
>> + Say Y here if you have the a touchscreen connected to your
>> + system using the Goodix Berlin IC connection via SPI.
>
> Same comment here with regard to diction.
>
>> +
>> + If unsure, say N.
>> +
>> + To compile this driver as a module, choose M here: the
>> + module will be called goodix_berlin_spi.
>> +
>> config TOUCHSCREEN_HIDEEP
>> tristate "HiDeep Touch IC"
>> depends on I2C
>> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
>> index 921a2da0c2be..29524e8a83db 100644
>> --- a/drivers/input/touchscreen/Makefile
>> +++ b/drivers/input/touchscreen/Makefile
>> @@ -49,6 +49,7 @@ 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-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_SPI) += goodix_berlin_spi.o
>> obj-$(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_spi.c b/drivers/input/touchscreen/goodix_berlin_spi.c
>> new file mode 100644
>> index 000000000000..0f4f650fdf3f
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/goodix_berlin_spi.c
>> @@ -0,0 +1,183 @@
>> +// 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/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/spi/spi.h>
>> +#include <linux/regmap.h>
>
> Please alphabetize these to aid readability.
>
>> +#include <asm/unaligned.h>
>> +
>> +#include "goodix_berlin.h"
>> +
>> +#define SPI_TRANS_PREFIX_LEN 1
>> +#define REGISTER_WIDTH 4
>> +#define SPI_READ_DUMMY_LEN 3
>> +#define SPI_READ_PREFIX_LEN (SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH + SPI_READ_DUMMY_LEN)
>> +#define SPI_WRITE_PREFIX_LEN (SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH)
>> +
>> +#define SPI_WRITE_FLAG 0xF0
>> +#define SPI_READ_FLAG 0xF1
>> +
>> +static int goodix_berlin_spi_read(void *context, const void *reg_buf,
>> + size_t reg_size, void *val_buf,
>> + size_t val_size)
>> +{
>> + struct spi_device *spi = context;
>> + struct spi_transfer xfers;
>> + struct spi_message spi_msg;
>> + const u32 *reg = reg_buf; /* reg is stored as native u32 at start of buffer */
>> + u8 *buf = NULL;
>> + int ret = 0;
>
> No need to initialize these, only to forcibly assign them later.
>
>> +
>> + if (reg_size != REGISTER_WIDTH)
>> + return -EINVAL;
>> +
>> + buf = kzalloc(SPI_READ_PREFIX_LEN + val_size, GFP_KERNEL);
>> + if (!buf)
>> + return -ENOMEM;
>> +
>> + spi_message_init(&spi_msg);
>> + memset(&xfers, 0, sizeof(xfers));
>> +
>> + /* buffer format: 0xF1 + addr(4bytes) + dummy(3bytes) + data */
>> + buf[0] = SPI_READ_FLAG;
>> + put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
>> + memset(buf + SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH, 0xff,
>> + SPI_READ_DUMMY_LEN);
>> +
>> + xfers.tx_buf = buf;
>> + xfers.rx_buf = buf;
>> + xfers.len = SPI_READ_PREFIX_LEN + val_size;
>> + xfers.cs_change = 0;
>> + spi_message_add_tail(&xfers, &spi_msg);
>> +
>> + ret = spi_sync(spi, &spi_msg);
>> + if (ret < 0) {
>> + dev_err(&spi->dev, "transfer error:%d", ret);
>> + goto exit;
>> + }
>
> My comment is purely idiomatic, but this seems cleaner:
>
> ret = ...
> if (ret)
> dev_err(...);
> else
> memcpy(...);
>
> kfree(...);
> return ret;
>
>> +
>> + memcpy(val_buf, buf + SPI_READ_PREFIX_LEN, val_size);
>> +exit:
>> + kfree(buf);
>> + return ret;
>> +}
>> +
>> +static int goodix_berlin_spi_write(void *context, const void *data,
>> + size_t count)
>> +{
>> + unsigned int len = count - REGISTER_WIDTH;
>> + struct spi_device *spi = context;
>> + struct spi_transfer xfers;
>> + struct spi_message spi_msg;
>> + const u32 *reg = data; /* reg is stored as native u32 at start of buffer */
>> + u8 *buf = NULL;
>> + int ret = 0;
>
> Same comment here with regard to initialization.
>
>> +
>> + buf = kzalloc(SPI_WRITE_PREFIX_LEN + len, GFP_KERNEL);
>> + if (!buf)
>> + return -ENOMEM;
>> +
>> + spi_message_init(&spi_msg);
>> + memset(&xfers, 0, sizeof(xfers));
>> +
>> + buf[0] = SPI_WRITE_FLAG;
>> + put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
>> + memcpy(buf + SPI_WRITE_PREFIX_LEN, data + REGISTER_WIDTH, len);
>> +
>> + xfers.tx_buf = buf;
>> + xfers.len = SPI_WRITE_PREFIX_LEN + len;
>> + xfers.cs_change = 0;
>> + spi_message_add_tail(&xfers, &spi_msg);
>> +
>> + ret = spi_sync(spi, &spi_msg);
>> + if (ret < 0)
>> + dev_err(&spi->dev, "transfer error:%d", ret);
>> +
>> + kfree(buf);
>> + return ret;
>> +}
>> +
>> +static const struct regmap_config goodix_berlin_spi_regmap_conf = {
>> + .reg_bits = 32,
>> + .val_bits = 8,
>> + .read = goodix_berlin_spi_read,
>> + .write = goodix_berlin_spi_write,
>> +};
>> +
>> +static const struct input_id goodix_berlin_spi_input_id = {
>> + .bustype = BUS_SPI,
>> + .vendor = 0x0416,
>> + .product = 0x1001,
>
> After having seen these in the I2C counterpart; consider defining them
> in goodix_berlin.h.
To be honest, I blindly copied it from goodix.c because the vendor
driver puts random values here.
input_dev->id.product = 0xDEAD;
input_dev->id.vendor = 0xBEEF;
So what should I set ?
Neil
>
>> +};
>> +
>> +static int goodix_berlin_spi_probe(struct spi_device *spi)
>> +{
>> + struct regmap_config *cfg;
>
> regmap_config
>
>> + struct regmap *map;
>
> regmap
>
> (see more examples in MFD where such dual-mode devices are common).
>
>> + size_t max_size;
>> + int ret = 0;
>> +
>> + cfg = devm_kmemdup(&spi->dev, &goodix_berlin_spi_regmap_conf,
>> + sizeof(*cfg), GFP_KERNEL);
>> + if (!cfg)
>> + return -ENOMEM;
>> +
>> + spi->mode = SPI_MODE_0;
>> + spi->bits_per_word = 8;
>> + ret = spi_setup(spi);
>> + if (ret)
>> + return ret;
>> +
>> + max_size = spi_max_transfer_size(spi);
>> + cfg->max_raw_read = max_size - SPI_READ_PREFIX_LEN;
>> + cfg->max_raw_write = max_size - SPI_WRITE_PREFIX_LEN;
>> +
>> + map = devm_regmap_init(&spi->dev, NULL, spi, cfg);
>> + if (IS_ERR(map))
>> + return PTR_ERR(map);
>> +
>> + return goodix_berlin_probe(&spi->dev, spi->irq,
>> + &goodix_berlin_spi_input_id, map);
>> +}
>> +
>> +static void goodix_berlin_spi_remove(struct spi_device *spi)
>> +{
>> + goodix_berlin_remove(&spi->dev);
>> +}
>> +
>> +static const struct of_device_id goodix_berlin_spi_of_match[] = {
>> + {
>> + .compatible = "goodix,gt9916",
>> + },
>
> This format is different than its I2C counterpart.
>
>> + { },
>
> Nit: same comment with regards to trailing commas.
>
>> +};
>> +MODULE_DEVICE_TABLE(of, goodix_berlin_spi_of_match);
>> +
>> +static const struct spi_device_id goodix_berlin_spi_ids[] = {
>> + { "gt9916" },
>> + { },
>
> And here.
>
>> +};
>> +MODULE_DEVICE_TABLE(spi, goodix_berlin_spi_ids);
>> +
>> +static struct spi_driver goodix_berlin_spi_driver = {
>> + .driver = {
>> + .name = "goodix-berlin-spi",
>> + .of_match_table = goodix_berlin_spi_of_match,
>> + .pm = pm_sleep_ptr(&goodix_berlin_pm_ops),
>> + },
>> + .id_table = goodix_berlin_spi_ids,
>> + .probe = goodix_berlin_spi_probe,
>> + .remove = goodix_berlin_spi_remove,
>> +};
>> +module_spi_driver(goodix_berlin_spi_driver);
>> +
>> +MODULE_LICENSE("GPL");
>> +MODULE_DESCRIPTION("Goodix Berlin SPI Touchscreen driver");
>> +MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>");
>>
>> --
>> 2.34.1
>>
>
> Kind regards,
> Jeff LaBundy
Hi Neil,
[...]
> > > +static const struct input_id goodix_berlin_spi_input_id = {
> > > + .bustype = BUS_SPI,
> > > + .vendor = 0x0416,
> > > + .product = 0x1001,
> >
> > After having seen these in the I2C counterpart; consider defining them
> > in goodix_berlin.h.
>
> To be honest, I blindly copied it from goodix.c because the vendor
> driver puts random values here.
>
> input_dev->id.product = 0xDEAD;
> input_dev->id.vendor = 0xBEEF;
>
> So what should I set ?
If there is no explicit guidance from the vendor, I would simply leave
these unassigned; in theory one would imagine that this controller would
have a different product ID than other models.
[...]
Kind regards,
Jeff LaBundy
On 12/06/2023 19:07, Jeff LaBundy wrote:
> Hi Neil,
>
> [...]
>
>>>> +static const struct input_id goodix_berlin_spi_input_id = {
>>>> + .bustype = BUS_SPI,
>>>> + .vendor = 0x0416,
>>>> + .product = 0x1001,
>>>
>>> After having seen these in the I2C counterpart; consider defining them
>>> in goodix_berlin.h.
>>
>> To be honest, I blindly copied it from goodix.c because the vendor
>> driver puts random values here.
>>
>> input_dev->id.product = 0xDEAD;
>> input_dev->id.vendor = 0xBEEF;
>>
>> So what should I set ?
>
> If there is no explicit guidance from the vendor, I would simply leave
> these unassigned; in theory one would imagine that this controller would
> have a different product ID than other models.
I'll leave those unassigned for now, and perhaps we could find
some firmware info value that could be used here.
Neil
>
> [...]
>
> Kind regards,
> Jeff LaBundy
@@ -435,6 +435,20 @@ config TOUCHSCREEN_GOODIX_BERLIN_I2C
To compile this driver as a module, choose M here: the
module will be called goodix_berlin_i2c.
+config TOUCHSCREEN_GOODIX_BERLIN_SPI
+ tristate "Goodix Berlin SPI touchscreen"
+ depends on SPI_MASTER
+ depends on REGMAP
+ select TOUCHSCREEN_GOODIX_BERLIN_CORE
+ help
+ Say Y here if you have the a touchscreen connected to your
+ system using the Goodix Berlin IC connection via SPI.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called goodix_berlin_spi.
+
config TOUCHSCREEN_HIDEEP
tristate "HiDeep Touch IC"
depends on I2C
@@ -49,6 +49,7 @@ 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-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_SPI) += goodix_berlin_spi.o
obj-$(CONFIG_TOUCHSCREEN_HIDEEP) += hideep.o
obj-$(CONFIG_TOUCHSCREEN_HYNITRON_CSTXXX) += hynitron_cstxxx.o
obj-$(CONFIG_TOUCHSCREEN_ILI210X) += ili210x.o
new file mode 100644
@@ -0,0 +1,183 @@
+// 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/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/regmap.h>
+#include <asm/unaligned.h>
+
+#include "goodix_berlin.h"
+
+#define SPI_TRANS_PREFIX_LEN 1
+#define REGISTER_WIDTH 4
+#define SPI_READ_DUMMY_LEN 3
+#define SPI_READ_PREFIX_LEN (SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH + SPI_READ_DUMMY_LEN)
+#define SPI_WRITE_PREFIX_LEN (SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH)
+
+#define SPI_WRITE_FLAG 0xF0
+#define SPI_READ_FLAG 0xF1
+
+static int goodix_berlin_spi_read(void *context, const void *reg_buf,
+ size_t reg_size, void *val_buf,
+ size_t val_size)
+{
+ struct spi_device *spi = context;
+ struct spi_transfer xfers;
+ struct spi_message spi_msg;
+ const u32 *reg = reg_buf; /* reg is stored as native u32 at start of buffer */
+ u8 *buf = NULL;
+ int ret = 0;
+
+ if (reg_size != REGISTER_WIDTH)
+ return -EINVAL;
+
+ buf = kzalloc(SPI_READ_PREFIX_LEN + val_size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ spi_message_init(&spi_msg);
+ memset(&xfers, 0, sizeof(xfers));
+
+ /* buffer format: 0xF1 + addr(4bytes) + dummy(3bytes) + data */
+ buf[0] = SPI_READ_FLAG;
+ put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
+ memset(buf + SPI_TRANS_PREFIX_LEN + REGISTER_WIDTH, 0xff,
+ SPI_READ_DUMMY_LEN);
+
+ xfers.tx_buf = buf;
+ xfers.rx_buf = buf;
+ xfers.len = SPI_READ_PREFIX_LEN + val_size;
+ xfers.cs_change = 0;
+ spi_message_add_tail(&xfers, &spi_msg);
+
+ ret = spi_sync(spi, &spi_msg);
+ if (ret < 0) {
+ dev_err(&spi->dev, "transfer error:%d", ret);
+ goto exit;
+ }
+
+ memcpy(val_buf, buf + SPI_READ_PREFIX_LEN, val_size);
+exit:
+ kfree(buf);
+ return ret;
+}
+
+static int goodix_berlin_spi_write(void *context, const void *data,
+ size_t count)
+{
+ unsigned int len = count - REGISTER_WIDTH;
+ struct spi_device *spi = context;
+ struct spi_transfer xfers;
+ struct spi_message spi_msg;
+ const u32 *reg = data; /* reg is stored as native u32 at start of buffer */
+ u8 *buf = NULL;
+ int ret = 0;
+
+ buf = kzalloc(SPI_WRITE_PREFIX_LEN + len, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ spi_message_init(&spi_msg);
+ memset(&xfers, 0, sizeof(xfers));
+
+ buf[0] = SPI_WRITE_FLAG;
+ put_unaligned_be32(*reg, buf + SPI_TRANS_PREFIX_LEN);
+ memcpy(buf + SPI_WRITE_PREFIX_LEN, data + REGISTER_WIDTH, len);
+
+ xfers.tx_buf = buf;
+ xfers.len = SPI_WRITE_PREFIX_LEN + len;
+ xfers.cs_change = 0;
+ spi_message_add_tail(&xfers, &spi_msg);
+
+ ret = spi_sync(spi, &spi_msg);
+ if (ret < 0)
+ dev_err(&spi->dev, "transfer error:%d", ret);
+
+ kfree(buf);
+ return ret;
+}
+
+static const struct regmap_config goodix_berlin_spi_regmap_conf = {
+ .reg_bits = 32,
+ .val_bits = 8,
+ .read = goodix_berlin_spi_read,
+ .write = goodix_berlin_spi_write,
+};
+
+static const struct input_id goodix_berlin_spi_input_id = {
+ .bustype = BUS_SPI,
+ .vendor = 0x0416,
+ .product = 0x1001,
+};
+
+static int goodix_berlin_spi_probe(struct spi_device *spi)
+{
+ struct regmap_config *cfg;
+ struct regmap *map;
+ size_t max_size;
+ int ret = 0;
+
+ cfg = devm_kmemdup(&spi->dev, &goodix_berlin_spi_regmap_conf,
+ sizeof(*cfg), GFP_KERNEL);
+ if (!cfg)
+ return -ENOMEM;
+
+ spi->mode = SPI_MODE_0;
+ spi->bits_per_word = 8;
+ ret = spi_setup(spi);
+ if (ret)
+ return ret;
+
+ max_size = spi_max_transfer_size(spi);
+ cfg->max_raw_read = max_size - SPI_READ_PREFIX_LEN;
+ cfg->max_raw_write = max_size - SPI_WRITE_PREFIX_LEN;
+
+ map = devm_regmap_init(&spi->dev, NULL, spi, cfg);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ return goodix_berlin_probe(&spi->dev, spi->irq,
+ &goodix_berlin_spi_input_id, map);
+}
+
+static void goodix_berlin_spi_remove(struct spi_device *spi)
+{
+ goodix_berlin_remove(&spi->dev);
+}
+
+static const struct of_device_id goodix_berlin_spi_of_match[] = {
+ {
+ .compatible = "goodix,gt9916",
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, goodix_berlin_spi_of_match);
+
+static const struct spi_device_id goodix_berlin_spi_ids[] = {
+ { "gt9916" },
+ { },
+};
+MODULE_DEVICE_TABLE(spi, goodix_berlin_spi_ids);
+
+static struct spi_driver goodix_berlin_spi_driver = {
+ .driver = {
+ .name = "goodix-berlin-spi",
+ .of_match_table = goodix_berlin_spi_of_match,
+ .pm = pm_sleep_ptr(&goodix_berlin_pm_ops),
+ },
+ .id_table = goodix_berlin_spi_ids,
+ .probe = goodix_berlin_spi_probe,
+ .remove = goodix_berlin_spi_remove,
+};
+module_spi_driver(goodix_berlin_spi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Goodix Berlin SPI Touchscreen driver");
+MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>");