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@xxxxxxxxxx> > --- Just a few comments below, then feel free to add: Reviewed-by: Jeff LaBundy <jeff@xxxxxxxxxxx> > 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@xxxxxxxxxx>"); > > -- > 2.34.1 > Kind regards, Jeff LaBundy
