drivers/input/touchscreen/goodix_fwupload.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Goodix Touchscreen firmware upload support
   4  *
   5  * Copyright (c) 2021 Hans de Goede <[email protected]>
   6  *
   7  * This is a rewrite of gt9xx_update.c from the Allwinner H3 BSP which is:
   8  * Copyright (c) 2010 - 2012 Goodix Technology.
   9  * Author: [email protected]
  10  */
  11
  12 #include <linux/device.h>
  13 #include <linux/firmware.h>
  14 #include <linux/i2c.h>
  15 #include "goodix.h"
  16
  17 #define GOODIX_FW_HEADER_LENGTH         sizeof(struct goodix_fw_header)
  18 #define GOODIX_FW_SECTION_LENGTH        0x2000
  19 #define GOODIX_FW_DSP_LENGTH            0x1000
  20 #define GOODIX_FW_UPLOAD_ADDRESS        0xc000
  21
  22 #define GOODIX_CFG_LOC_HAVE_KEY          7
  23 #define GOODIX_CFG_LOC_DRVA_NUM         27
  24 #define GOODIX_CFG_LOC_DRVB_NUM         28
  25 #define GOODIX_CFG_LOC_SENS_NUM         29
  26
  27 struct goodix_fw_header {
  28         u8 hw_info[4];
  29         u8 pid[8];
  30         u8 vid[2];
  31 } __packed;
  32
  33 static u16 goodix_firmware_checksum(const u8 *data, int size)
  34 {
  35         u16 checksum = 0;
  36         int i;
  37
  38         for (i = 0; i < size; i += 2)
  39                 checksum += (data[i] << 8) + data[i + 1];
  40
  41         return checksum;
  42 }
  43
  44 static int goodix_firmware_verify(struct device *dev, const struct firmware *fw)
  45 {
  46         const struct goodix_fw_header *fw_header;
  47         size_t expected_size;
  48         const u8 *data;
  49         u16 checksum;
  50         char buf[9];
  51
  52         expected_size = GOODIX_FW_HEADER_LENGTH + 4 * GOODIX_FW_SECTION_LENGTH +
  53                         GOODIX_FW_DSP_LENGTH;
  54         if (fw->size != expected_size) {
  55                 dev_err(dev, "Firmware has wrong size, expected %zu got %zu\n",
  56                         expected_size, fw->size);
  57                 return -EINVAL;
  58         }
  59
  60         data = fw->data + GOODIX_FW_HEADER_LENGTH;
  61         checksum = goodix_firmware_checksum(data, 4 * GOODIX_FW_SECTION_LENGTH);
  62         if (checksum) {
  63                 dev_err(dev, "Main firmware checksum error\n");
  64                 return -EINVAL;
  65         }
  66
  67         data += 4 * GOODIX_FW_SECTION_LENGTH;
  68         checksum = goodix_firmware_checksum(data, GOODIX_FW_DSP_LENGTH);
  69         if (checksum) {
  70                 dev_err(dev, "DSP firmware checksum error\n");
  71                 return -EINVAL;
  72         }
  73
  74         fw_header = (const struct goodix_fw_header *)fw->data;
  75         dev_info(dev, "Firmware hardware info %02x%02x%02x%02x\n",
  76                  fw_header->hw_info[0], fw_header->hw_info[1],
  77                  fw_header->hw_info[2], fw_header->hw_info[3]);
  78         /* pid is a 8 byte buffer containing a string, weird I know */
  79         memcpy(buf, fw_header->pid, 8);
  80         buf[8] = 0;
  81         dev_info(dev, "Firmware PID: %s VID: %02x%02x\n", buf,
  82                  fw_header->vid[0], fw_header->vid[1]);
  83         return 0;
  84 }
  85
  86 static int goodix_enter_upload_mode(struct i2c_client *client)
  87 {
  88         int tries, error;
  89         u8 val;
  90
  91         tries = 200;
  92         do {
  93                 error = goodix_i2c_write_u8(client,
  94                                             GOODIX_REG_MISCTL_SWRST, 0x0c);
  95                 if (error)
  96                         return error;
  97
  98                 error = goodix_i2c_read(client,
  99                                         GOODIX_REG_MISCTL_SWRST, &val, 1);
 100                 if (error)
 101                         return error;
 102
 103                 if (val == 0x0c)
 104                         break;
 105         } while (--tries);
 106
 107         if (!tries) {
 108                 dev_err(&client->dev, "Error could not hold ss51 & dsp\n");
 109                 return -EIO;
 110         }
 111
 112         /* DSP_CK and DSP_ALU_CK PowerOn */
 113         error = goodix_i2c_write_u8(client, GOODIX_REG_MISCTL_DSP_CTL, 0x00);
 114         if (error)
 115                 return error;
 116
 117         /* Disable watchdog */
 118         error = goodix_i2c_write_u8(client, GOODIX_REG_MISCTL_TMR0_EN, 0x00);
 119         if (error)
 120                 return error;
 121
 122         /* Clear cache enable */
 123         error = goodix_i2c_write_u8(client, GOODIX_REG_MISCTL_CACHE_EN, 0x00);
 124         if (error)
 125                 return error;
 126
 127         /* Set boot from SRAM */
 128         error = goodix_i2c_write_u8(client, GOODIX_REG_MISCTL_BOOTCTL, 0x02);
 129         if (error)
 130                 return error;
 131
 132         /* Software reboot */
 133         error = goodix_i2c_write_u8(client,
 134                                     GOODIX_REG_MISCTL_CPU_SWRST_PULSE, 0x01);
 135         if (error)
 136                 return error;
 137
 138         /* Clear control flag */
 139         error = goodix_i2c_write_u8(client, GOODIX_REG_MISCTL_BOOTCTL, 0x00);
 140         if (error)
 141                 return error;
 142
 143         /* Set scramble */
 144         error = goodix_i2c_write_u8(client, GOODIX_REG_MISCTL_BOOT_OPT, 0x00);
 145         if (error)
 146                 return error;
 147
 148         /* Enable accessing code */
 149         error = goodix_i2c_write_u8(client, GOODIX_REG_MISCTL_MEM_CD_EN, 0x01);
 150         if (error)
 151                 return error;
 152
 153         return 0;
 154 }
 155
 156 static int goodix_start_firmware(struct i2c_client *client)
 157 {
 158         int error;
 159         u8 val;
 160
 161         /* Init software watchdog */
 162         error = goodix_i2c_write_u8(client, GOODIX_REG_SW_WDT, 0xaa);
 163         if (error)
 164                 return error;
 165
 166         /* Release SS51 & DSP */
 167         error = goodix_i2c_write_u8(client, GOODIX_REG_MISCTL_SWRST, 0x00);
 168         if (error)
 169                 return error;
 170
 171         error = goodix_i2c_read(client, GOODIX_REG_SW_WDT, &val, 1);
 172         if (error)
 173                 return error;
 174
 175         /* The value we've written to SW_WDT should have been cleared now */
 176         if (val == 0xaa) {
 177                 dev_err(&client->dev, "Error SW_WDT reg not cleared on fw startup\n");
 178                 return -EIO;
 179         }
 180
 181         /* Re-init software watchdog */
 182         error = goodix_i2c_write_u8(client, GOODIX_REG_SW_WDT, 0xaa);
 183         if (error)
 184                 return error;
 185
 186         return 0;
 187 }
 188
 189 static int goodix_firmware_upload(struct goodix_ts_data *ts)
 190 {
 191         const struct firmware *fw;
 192         char fw_name[64];
 193         const u8 *data;
 194         int error;
 195
 196         snprintf(fw_name, sizeof(fw_name), "goodix/%s", ts->firmware_name);
 197
 198         error = request_firmware(&fw, fw_name, &ts->client->dev);
 199         if (error) {
 200                 dev_err(&ts->client->dev, "Firmware request error %d\n", error);
 201                 return error;
 202         }
 203
 204         error = goodix_firmware_verify(&ts->client->dev, fw);
 205         if (error)
 206                 goto release;
 207
 208         error = goodix_reset_no_int_sync(ts);
 209         if (error)
 210                 goto release;
 211
 212         error = goodix_enter_upload_mode(ts->client);
 213         if (error)
 214                 goto release;
 215
 216         /* Select SRAM bank 0 and upload section 1 & 2 */
 217         error = goodix_i2c_write_u8(ts->client,
 218                                     GOODIX_REG_MISCTL_SRAM_BANK, 0x00);
 219         if (error)
 220                 goto release;
 221
 222         data = fw->data + GOODIX_FW_HEADER_LENGTH;
 223         error = goodix_i2c_write(ts->client, GOODIX_FW_UPLOAD_ADDRESS,
 224                                  data, 2 * GOODIX_FW_SECTION_LENGTH);
 225         if (error)
 226                 goto release;
 227
 228         /* Select SRAM bank 1 and upload section 3 & 4 */
 229         error = goodix_i2c_write_u8(ts->client,
 230                                     GOODIX_REG_MISCTL_SRAM_BANK, 0x01);
 231         if (error)
 232                 goto release;
 233
 234         data += 2 * GOODIX_FW_SECTION_LENGTH;
 235         error = goodix_i2c_write(ts->client, GOODIX_FW_UPLOAD_ADDRESS,
 236                                  data, 2 * GOODIX_FW_SECTION_LENGTH);
 237         if (error)
 238                 goto release;
 239
 240         /* Select SRAM bank 2 and upload the DSP firmware */
 241         error = goodix_i2c_write_u8(ts->client,
 242                                     GOODIX_REG_MISCTL_SRAM_BANK, 0x02);
 243         if (error)
 244                 goto release;
 245
 246         data += 2 * GOODIX_FW_SECTION_LENGTH;
 247         error = goodix_i2c_write(ts->client, GOODIX_FW_UPLOAD_ADDRESS,
 248                                  data, GOODIX_FW_DSP_LENGTH);
 249         if (error)
 250                 goto release;
 251
 252         error = goodix_start_firmware(ts->client);
 253         if (error)
 254                 goto release;
 255
 256         error = goodix_int_sync(ts);
 257 release:
 258         release_firmware(fw);
 259         return error;
 260 }
 261
 262 static int goodix_prepare_bak_ref(struct goodix_ts_data *ts)
 263 {
 264         u8 have_key, driver_num, sensor_num;
 265
 266         if (ts->bak_ref)
 267                 return 0; /* Already done */
 268
 269         have_key = (ts->config[GOODIX_CFG_LOC_HAVE_KEY] & 0x01);
 270
 271         driver_num = (ts->config[GOODIX_CFG_LOC_DRVA_NUM] & 0x1f) +
 272                      (ts->config[GOODIX_CFG_LOC_DRVB_NUM] & 0x1f);
 273         if (have_key)
 274                 driver_num--;
 275
 276         sensor_num = (ts->config[GOODIX_CFG_LOC_SENS_NUM] & 0x0f) +
 277                      ((ts->config[GOODIX_CFG_LOC_SENS_NUM] >> 4) & 0x0f);
 278
 279         dev_dbg(&ts->client->dev, "Drv %d Sen %d Key %d\n",
 280                 driver_num, sensor_num, have_key);
 281
 282         ts->bak_ref_len = (driver_num * (sensor_num - 2) + 2) * 2;
 283
 284         ts->bak_ref = devm_kzalloc(&ts->client->dev,
 285                                    ts->bak_ref_len, GFP_KERNEL);
 286         if (!ts->bak_ref)
 287                 return -ENOMEM;
 288
 289         /*
 290          * The bak_ref array contains the backup of an array of (self/auto)
 291          * calibration related values which the Android version of the driver
 292          * stores on the filesystem so that it can be restored after reboot.
 293          * The mainline kernel never writes directly to the filesystem like
 294          * this, we always start will all the values which give a correction
 295          * factor in approx. the -20 - +20 range (in 2s complement) set to 0.
 296          *
 297          * Note the touchscreen works fine without restoring the reference
 298          * values after a reboot / power-cycle.
 299          *
 300          * The last 2 bytes are a 16 bits unsigned checksum which is expected
 301          * to make the addition al all 16 bit unsigned values in the array add
 302          * up to 1 (rather then the usual 0), so we must set the last byte to 1.
 303          */
 304         ts->bak_ref[ts->bak_ref_len - 1] = 1;
 305
 306         return 0;
 307 }
 308
 309 static int goodix_send_main_clock(struct goodix_ts_data *ts)
 310 {
 311         u32 main_clk = 54; /* Default main clock */
 312         u8 checksum = 0;
 313         int i;
 314
 315         device_property_read_u32(&ts->client->dev,
 316                                  "goodix,main-clk", &main_clk);
 317
 318         for (i = 0; i < (GOODIX_MAIN_CLK_LEN - 1); i++) {
 319                 ts->main_clk[i] = main_clk;
 320                 checksum += main_clk;
 321         }
 322
 323         /* The value of all bytes combines must be 0 */
 324         ts->main_clk[GOODIX_MAIN_CLK_LEN - 1] = 256 - checksum;
 325
 326         return goodix_i2c_write(ts->client, GOODIX_REG_MAIN_CLK,
 327                                 ts->main_clk, GOODIX_MAIN_CLK_LEN);
 328 }
 329
 330 int goodix_firmware_check(struct goodix_ts_data *ts)
 331 {
 332         device_property_read_string(&ts->client->dev,
 333                                     "firmware-name", &ts->firmware_name);
 334         if (!ts->firmware_name)
 335                 return 0;
 336
 337         if (ts->irq_pin_access_method == IRQ_PIN_ACCESS_NONE) {
 338                 dev_err(&ts->client->dev, "Error no IRQ-pin access method, cannot upload fw.\n");
 339                 return -EINVAL;
 340         }
 341
 342         dev_info(&ts->client->dev, "Touchscreen controller needs fw-upload\n");
 343         ts->load_cfg_from_disk = true;
 344
 345         return goodix_firmware_upload(ts);
 346 }
 347
 348 bool goodix_handle_fw_request(struct goodix_ts_data *ts)
 349 {
 350         int error;
 351         u8 val;
 352
 353         error = goodix_i2c_read(ts->client, GOODIX_REG_REQUEST, &val, 1);
 354         if (error)
 355                 return false;
 356
 357         switch (val) {
 358         case GOODIX_RQST_RESPONDED:
 359                 /*
 360                  * If we read back our own last ack the IRQ was not for
 361                  * a request.
 362                  */
 363                 return false;
 364         case GOODIX_RQST_CONFIG:
 365                 error = goodix_send_cfg(ts, ts->config, ts->chip->config_len);
 366                 if (error)
 367                         return false;
 368
 369                 break;
 370         case GOODIX_RQST_BAK_REF:
 371                 error = goodix_prepare_bak_ref(ts);
 372                 if (error)
 373                         return false;
 374
 375                 error = goodix_i2c_write(ts->client, GOODIX_REG_BAK_REF,
 376                                          ts->bak_ref, ts->bak_ref_len);
 377                 if (error)
 378                         return false;
 379
 380                 break;
 381         case GOODIX_RQST_RESET:
 382                 error = goodix_firmware_upload(ts);
 383                 if (error)
 384                         return false;
 385
 386                 break;
 387         case GOODIX_RQST_MAIN_CLOCK:
 388                 error = goodix_send_main_clock(ts);
 389                 if (error)
 390                         return false;
 391
 392                 break;
 393         case GOODIX_RQST_UNKNOWN:
 394         case GOODIX_RQST_IDLE:
 395                 break;
 396         default:
 397                 dev_err_ratelimited(&ts->client->dev, "Unknown Request: 0x%02x\n", val);
 398         }
 399
 400         /* Ack the request */
 401         goodix_i2c_write_u8(ts->client,
 402                             GOODIX_REG_REQUEST, GOODIX_RQST_RESPONDED);
 403         return true;
 404 }
 405
 406 void goodix_save_bak_ref(struct goodix_ts_data *ts)
 407 {
 408         int error;
 409         u8 val;
 410
 411         if (!ts->firmware_name)
 412                 return;
 413
 414         error = goodix_i2c_read(ts->client, GOODIX_REG_STATUS, &val, 1);
 415         if (error)
 416                 return;
 417
 418         if (!(val & 0x80))
 419                 return;
 420
 421         error = goodix_i2c_read(ts->client, GOODIX_REG_BAK_REF,
 422                                 ts->bak_ref, ts->bak_ref_len);
 423         if (error) {
 424                 memset(ts->bak_ref, 0, ts->bak_ref_len);
 425                 ts->bak_ref[ts->bak_ref_len - 1] = 1;
 426         }
 427 }