1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Goodix Berlin Touchscreen Driver 4 * 5 * Copyright (C) 2020 - 2021 Goodix, Inc. 6 * Copyright (C) 2023 Linaro Ltd. 7 * 8 * Based on goodix_ts_berlin driver. 9 */ 10 #include <linux/unaligned.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/regmap.h> 14 #include <linux/spi/spi.h> 15 #include <linux/input.h> 16 17 #include "goodix_berlin.h" 18 19 #define GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN 1 20 #define GOODIX_BERLIN_REGISTER_WIDTH 4 21 #define GOODIX_BERLIN_SPI_READ_DUMMY_LEN_A 4 22 #define GOODIX_BERLIN_SPI_READ_DUMMY_LEN_D 3 23 #define GOODIX_BERLIN_SPI_READ_PREFIX_LEN_A (GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + \ 24 GOODIX_BERLIN_REGISTER_WIDTH + \ 25 GOODIX_BERLIN_SPI_READ_DUMMY_LEN_A) 26 #define GOODIX_BERLIN_SPI_READ_PREFIX_LEN_D (GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + \ 27 GOODIX_BERLIN_REGISTER_WIDTH + \ 28 GOODIX_BERLIN_SPI_READ_DUMMY_LEN_D) 29 #define GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN (GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + \ 30 GOODIX_BERLIN_REGISTER_WIDTH) 31 32 #define GOODIX_BERLIN_SPI_WRITE_FLAG 0xF0 33 #define GOODIX_BERLIN_SPI_READ_FLAG 0xF1 34 35 static int goodix_berlin_spi_read(void *context, const void *reg_buf, 36 size_t reg_size, void *val_buf, 37 size_t val_size) 38 { 39 struct spi_device *spi = context; 40 const struct goodix_berlin_ic_data *ic_data = spi_get_device_match_data(spi); 41 struct spi_transfer xfers; 42 struct spi_message spi_msg; 43 const u32 *reg = reg_buf; /* reg is stored as native u32 at start of buffer */ 44 int error; 45 46 if (reg_size != GOODIX_BERLIN_REGISTER_WIDTH) 47 return -EINVAL; 48 49 u8 *buf __free(kfree) = 50 kzalloc(ic_data->read_prefix_len + val_size, GFP_KERNEL); 51 if (!buf) 52 return -ENOMEM; 53 54 spi_message_init(&spi_msg); 55 memset(&xfers, 0, sizeof(xfers)); 56 57 /* buffer format: 0xF1 + addr(4bytes) + dummy(3/4bytes) + data */ 58 buf[0] = GOODIX_BERLIN_SPI_READ_FLAG; 59 put_unaligned_be32(*reg, buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN); 60 memset(buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + GOODIX_BERLIN_REGISTER_WIDTH, 61 0xff, ic_data->read_dummy_len); 62 63 xfers.tx_buf = buf; 64 xfers.rx_buf = buf; 65 xfers.len = ic_data->read_prefix_len + val_size; 66 xfers.cs_change = 0; 67 spi_message_add_tail(&xfers, &spi_msg); 68 69 error = spi_sync(spi, &spi_msg); 70 if (error < 0) { 71 dev_err(&spi->dev, "spi transfer error, %d", error); 72 return error; 73 } 74 75 memcpy(val_buf, buf + ic_data->read_prefix_len, val_size); 76 return error; 77 } 78 79 static int goodix_berlin_spi_write(void *context, const void *data, 80 size_t count) 81 { 82 unsigned int len = count - GOODIX_BERLIN_REGISTER_WIDTH; 83 struct spi_device *spi = context; 84 struct spi_transfer xfers; 85 struct spi_message spi_msg; 86 const u32 *reg = data; /* reg is stored as native u32 at start of buffer */ 87 int error; 88 89 u8 *buf __free(kfree) = 90 kzalloc(GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN + len, GFP_KERNEL); 91 if (!buf) 92 return -ENOMEM; 93 94 spi_message_init(&spi_msg); 95 memset(&xfers, 0, sizeof(xfers)); 96 97 buf[0] = GOODIX_BERLIN_SPI_WRITE_FLAG; 98 put_unaligned_be32(*reg, buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN); 99 memcpy(buf + GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN, 100 data + GOODIX_BERLIN_REGISTER_WIDTH, len); 101 102 xfers.tx_buf = buf; 103 xfers.len = GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN + len; 104 xfers.cs_change = 0; 105 spi_message_add_tail(&xfers, &spi_msg); 106 107 error = spi_sync(spi, &spi_msg); 108 if (error < 0) { 109 dev_err(&spi->dev, "spi transfer error, %d", error); 110 return error; 111 } 112 113 return 0; 114 } 115 116 static const struct regmap_config goodix_berlin_spi_regmap_conf = { 117 .reg_bits = 32, 118 .val_bits = 8, 119 .read = goodix_berlin_spi_read, 120 .write = goodix_berlin_spi_write, 121 }; 122 123 /* vendor & product left unassigned here, should probably be updated from fw info */ 124 static const struct input_id goodix_berlin_spi_input_id = { 125 .bustype = BUS_SPI, 126 }; 127 128 static int goodix_berlin_spi_probe(struct spi_device *spi) 129 { 130 const struct goodix_berlin_ic_data *ic_data = spi_get_device_match_data(spi); 131 struct regmap_config regmap_config; 132 struct regmap *regmap; 133 size_t max_size; 134 int error = 0; 135 136 spi->mode = SPI_MODE_0; 137 spi->bits_per_word = 8; 138 error = spi_setup(spi); 139 if (error) 140 return error; 141 142 max_size = spi_max_transfer_size(spi); 143 144 regmap_config = goodix_berlin_spi_regmap_conf; 145 regmap_config.max_raw_read = max_size - ic_data->read_prefix_len; 146 regmap_config.max_raw_write = max_size - GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN; 147 148 regmap = devm_regmap_init(&spi->dev, NULL, spi, ®map_config); 149 if (IS_ERR(regmap)) 150 return PTR_ERR(regmap); 151 152 error = goodix_berlin_probe(&spi->dev, spi->irq, 153 &goodix_berlin_spi_input_id, regmap, 154 ic_data); 155 if (error) 156 return error; 157 158 return 0; 159 } 160 161 static const struct goodix_berlin_ic_data gt9897_data = { 162 .fw_version_info_addr = GOODIX_BERLIN_FW_VERSION_INFO_ADDR_A, 163 .ic_info_addr = GOODIX_BERLIN_IC_INFO_ADDR_A, 164 .read_dummy_len = GOODIX_BERLIN_SPI_READ_DUMMY_LEN_A, 165 .read_prefix_len = GOODIX_BERLIN_SPI_READ_PREFIX_LEN_A, 166 }; 167 168 static const struct goodix_berlin_ic_data gt9916_data = { 169 .fw_version_info_addr = GOODIX_BERLIN_FW_VERSION_INFO_ADDR_D, 170 .ic_info_addr = GOODIX_BERLIN_IC_INFO_ADDR_D, 171 .read_dummy_len = GOODIX_BERLIN_SPI_READ_DUMMY_LEN_D, 172 .read_prefix_len = GOODIX_BERLIN_SPI_READ_PREFIX_LEN_D, 173 }; 174 175 static const struct spi_device_id goodix_berlin_spi_ids[] = { 176 { .name = "gt9897", .driver_data = (long)>9897_data }, 177 { .name = "gt9916", .driver_data = (long)>9916_data }, 178 { }, 179 }; 180 MODULE_DEVICE_TABLE(spi, goodix_berlin_spi_ids); 181 182 static const struct of_device_id goodix_berlin_spi_of_match[] = { 183 { .compatible = "goodix,gt9897", .data = >9897_data }, 184 { .compatible = "goodix,gt9916", .data = >9916_data }, 185 { } 186 }; 187 MODULE_DEVICE_TABLE(of, goodix_berlin_spi_of_match); 188 189 static struct spi_driver goodix_berlin_spi_driver = { 190 .driver = { 191 .name = "goodix-berlin-spi", 192 .of_match_table = goodix_berlin_spi_of_match, 193 .pm = pm_sleep_ptr(&goodix_berlin_pm_ops), 194 .dev_groups = goodix_berlin_groups, 195 }, 196 .probe = goodix_berlin_spi_probe, 197 .id_table = goodix_berlin_spi_ids, 198 }; 199 module_spi_driver(goodix_berlin_spi_driver); 200 201 MODULE_LICENSE("GPL"); 202 MODULE_DESCRIPTION("Goodix Berlin SPI Touchscreen driver"); 203 MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>"); 204