| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <ZJiXopmFr4dPbqll@nixie71>
Date: Sun, 25 Jun 2023 14:38:10 -0500
From: Jeff LaBundy <jeff@...undy.com>
To: Neil Armstrong <neil.armstrong@...aro.org>
Cc: Dmitry Torokhov <dmitry.torokhov@...il.com>,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Conor Dooley <conor+dt@...nel.org>,
Bastien Nocera <hadess@...ess.net>,
Hans de Goede <hdegoede@...hat.com>,
Henrik Rydberg <rydberg@...math.org>,
linux-input@...r.kernel.org, linux-arm-msm@...r.kernel.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 4/4] input: touchscreen: add SPI support for Goodix
Berlin Touchscreen IC
Hi Neil,
On Thu, Jun 22, 2023 at 04:29:02PM +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@...aro.org>
> ---
Just a few comments below, then feel free to add:
Reviewed-by: Jeff LaBundy <jeff@...undy.com>
> drivers/input/touchscreen/Kconfig | 13 ++
> drivers/input/touchscreen/Makefile | 1 +
> drivers/input/touchscreen/goodix_berlin_spi.c | 172 ++++++++++++++++++++++++++
> 3 files changed, 186 insertions(+)
>
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 5e21cca6025d..2d86615e5090 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -435,6 +435,19 @@ 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
select REGMAP
(keep "depends on SPI_MASTER")
> + select TOUCHSCREEN_GOODIX_BERLIN_CORE
> + help
> + Say Y here if you have a Goodix Berlin IC connected to
> + your system 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
> 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..3a1bc251b32d
> --- /dev/null
> +++ b/drivers/input/touchscreen/goodix_berlin_spi.c
> @@ -0,0 +1,172 @@
> +// 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 <asm/unaligned.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/spi/spi.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
Please namespace all of these as you have done in the core driver.
> +
> +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;
> + int ret;
int error;
> +
> + 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);
error = spi_sync(...);
> + if (ret < 0)
if (error)
> + dev_err(&spi->dev, "transfer error:%d", ret);
> + else
> + memcpy(val_buf, buf + SPI_READ_PREFIX_LEN, val_size);
> +
> + 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;
> + int ret;
Same comments here regarding 'error' vs. 'ret'.
> +
> + 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,
> +};
> +
> +/* vendor & product left unassigned here, should probably be updated from fw info */
> +static const struct input_id goodix_berlin_spi_input_id = {
> + .bustype = BUS_SPI,
> +};
> +
> +static int goodix_berlin_spi_probe(struct spi_device *spi)
> +{
> + struct regmap_config *regmap_config;
> + struct regmap *regmap;
> + size_t max_size;
> + int error = 0;
> +
> + regmap_config = devm_kmemdup(&spi->dev, &goodix_berlin_spi_regmap_conf,
> + sizeof(*regmap_config), GFP_KERNEL);
> + if (!regmap_config)
> + return -ENOMEM;
Is there any reason we cannot simply pass goodix_berlin_spi_regmap_conf to
devm_regmap_init() below? Why to duplicate and pass the copy?
For reference, BMP280 in IIO is a similar example of a device with regmap
sitting atop a bespoke SPI protocol; it does not seem to take this extra
step.
> +
> + spi->mode = SPI_MODE_0;
> + spi->bits_per_word = 8;
> + error = spi_setup(spi);
> + if (error)
> + return error;
> +
> + max_size = spi_max_transfer_size(spi);
> + regmap_config->max_raw_read = max_size - SPI_READ_PREFIX_LEN;
> + regmap_config->max_raw_write = max_size - SPI_WRITE_PREFIX_LEN;
> +
> + regmap = devm_regmap_init(&spi->dev, NULL, spi, regmap_config);
> + if (IS_ERR(regmap))
> + return PTR_ERR(regmap);
> +
> + return goodix_berlin_probe(&spi->dev, spi->irq,
> + &goodix_berlin_spi_input_id, regmap);
> +}
> +
> +static const struct spi_device_id goodix_berlin_spi_ids[] = {
> + { "gt9916" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(spi, goodix_berlin_spi_ids);
> +
> +static const struct of_device_id goodix_berlin_spi_of_match[] = {
> + { .compatible = "goodix,gt9916", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, goodix_berlin_spi_of_match);
> +
> +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),
> + },
> + .probe = goodix_berlin_spi_probe,
> + .id_table = goodix_berlin_spi_ids,
> +};
> +module_spi_driver(goodix_berlin_spi_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Goodix Berlin SPI Touchscreen driver");
> +MODULE_AUTHOR("Neil Armstrong <neil.armstrong@...aro.org>");
>
> --
> 2.34.1
>
Kind regards,
Jeff LaBundy
Powered by blists - more mailing lists