diff options
Diffstat (limited to 'drivers/input/touchscreen/goodix_berlin_spi.c')
| -rw-r--r-- | drivers/input/touchscreen/goodix_berlin_spi.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/goodix_berlin_spi.c b/drivers/input/touchscreen/goodix_berlin_spi.c new file mode 100644 index 0000000000..4cc557da04 --- /dev/null +++ b/drivers/input/touchscreen/goodix_berlin_spi.c @@ -0,0 +1,178 @@ +// 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 <linux/input.h> + +#include "goodix_berlin.h" + +#define GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN 1 +#define GOODIX_BERLIN_REGISTER_WIDTH 4 +#define GOODIX_BERLIN_SPI_READ_DUMMY_LEN 3 +#define GOODIX_BERLIN_SPI_READ_PREFIX_LEN (GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + \ + GOODIX_BERLIN_REGISTER_WIDTH + \ + GOODIX_BERLIN_SPI_READ_DUMMY_LEN) +#define GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN (GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + \ + GOODIX_BERLIN_REGISTER_WIDTH) + +#define GOODIX_BERLIN_SPI_WRITE_FLAG 0xF0 +#define GOODIX_BERLIN_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; + int error; + + if (reg_size != GOODIX_BERLIN_REGISTER_WIDTH) + return -EINVAL; + + buf = kzalloc(GOODIX_BERLIN_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] = GOODIX_BERLIN_SPI_READ_FLAG; + put_unaligned_be32(*reg, buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN); + memset(buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + GOODIX_BERLIN_REGISTER_WIDTH, + 0xff, GOODIX_BERLIN_SPI_READ_DUMMY_LEN); + + xfers.tx_buf = buf; + xfers.rx_buf = buf; + xfers.len = GOODIX_BERLIN_SPI_READ_PREFIX_LEN + val_size; + xfers.cs_change = 0; + spi_message_add_tail(&xfers, &spi_msg); + + error = spi_sync(spi, &spi_msg); + if (error < 0) + dev_err(&spi->dev, "spi transfer error, %d", error); + else + memcpy(val_buf, buf + GOODIX_BERLIN_SPI_READ_PREFIX_LEN, val_size); + + kfree(buf); + return error; +} + +static int goodix_berlin_spi_write(void *context, const void *data, + size_t count) +{ + unsigned int len = count - GOODIX_BERLIN_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 error; + + buf = kzalloc(GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN + len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + spi_message_init(&spi_msg); + memset(&xfers, 0, sizeof(xfers)); + + buf[0] = GOODIX_BERLIN_SPI_WRITE_FLAG; + put_unaligned_be32(*reg, buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN); + memcpy(buf + GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN, + data + GOODIX_BERLIN_REGISTER_WIDTH, len); + + xfers.tx_buf = buf; + xfers.len = GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN + len; + xfers.cs_change = 0; + spi_message_add_tail(&xfers, &spi_msg); + + error = spi_sync(spi, &spi_msg); + if (error < 0) + dev_err(&spi->dev, "spi transfer error, %d", error); + + kfree(buf); + return error; +} + +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; + + 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 = goodix_berlin_spi_regmap_conf; + regmap_config.max_raw_read = max_size - GOODIX_BERLIN_SPI_READ_PREFIX_LEN; + regmap_config.max_raw_write = max_size - GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN; + + regmap = devm_regmap_init(&spi->dev, NULL, spi, ®map_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + error = goodix_berlin_probe(&spi->dev, spi->irq, + &goodix_berlin_spi_input_id, regmap); + if (error) + return error; + + return 0; +} + +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@linaro.org>"); |