1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * TI Touch Screen / ADC MFD driver 4 * 5 * Copyright (C) 2012 Texas Instruments Incorporated - https://www.ti.com/ 6 */ 7 8 #include <linux/module.h> 9 #include <linux/slab.h> 10 #include <linux/err.h> 11 #include <linux/io.h> 12 #include <linux/clk.h> 13 #include <linux/regmap.h> 14 #include <linux/mfd/core.h> 15 #include <linux/pm_runtime.h> 16 #include <linux/of.h> 17 #include <linux/platform_device.h> 18 #include <linux/sched.h> 19 20 #include <linux/mfd/ti_am335x_tscadc.h> 21 22 static const struct regmap_config tscadc_regmap_config = { 23 .name = "ti_tscadc", 24 .reg_bits = 32, 25 .reg_stride = 4, 26 .val_bits = 32, 27 }; 28 29 void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tscadc, u32 val) 30 { 31 unsigned long flags; 32 33 spin_lock_irqsave(&tscadc->reg_lock, flags); 34 tscadc->reg_se_cache |= val; 35 if (tscadc->adc_waiting) 36 wake_up(&tscadc->reg_se_wait); 37 else if (!tscadc->adc_in_use) 38 regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache); 39 40 spin_unlock_irqrestore(&tscadc->reg_lock, flags); 41 } 42 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache); 43 44 static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tscadc) 45 { 46 DEFINE_WAIT(wait); 47 u32 reg; 48 49 regmap_read(tscadc->regmap, REG_ADCFSM, ®); 50 if (reg & SEQ_STATUS) { 51 tscadc->adc_waiting = true; 52 prepare_to_wait(&tscadc->reg_se_wait, &wait, 53 TASK_UNINTERRUPTIBLE); 54 spin_unlock_irq(&tscadc->reg_lock); 55 56 schedule(); 57 58 spin_lock_irq(&tscadc->reg_lock); 59 finish_wait(&tscadc->reg_se_wait, &wait); 60 61 /* 62 * Sequencer should either be idle or 63 * busy applying the charge step. 64 */ 65 regmap_read(tscadc->regmap, REG_ADCFSM, ®); 66 WARN_ON((reg & SEQ_STATUS) && !(reg & CHARGE_STEP)); 67 tscadc->adc_waiting = false; 68 } 69 tscadc->adc_in_use = true; 70 } 71 72 void am335x_tsc_se_set_once(struct ti_tscadc_dev *tscadc, u32 val) 73 { 74 spin_lock_irq(&tscadc->reg_lock); 75 am335x_tscadc_need_adc(tscadc); 76 77 regmap_write(tscadc->regmap, REG_SE, val); 78 spin_unlock_irq(&tscadc->reg_lock); 79 } 80 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once); 81 82 void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tscadc) 83 { 84 unsigned long flags; 85 86 spin_lock_irqsave(&tscadc->reg_lock, flags); 87 tscadc->adc_in_use = false; 88 regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache); 89 spin_unlock_irqrestore(&tscadc->reg_lock, flags); 90 } 91 EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done); 92 93 void am335x_tsc_se_clr(struct ti_tscadc_dev *tscadc, u32 val) 94 { 95 unsigned long flags; 96 97 spin_lock_irqsave(&tscadc->reg_lock, flags); 98 tscadc->reg_se_cache &= ~val; 99 regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache); 100 spin_unlock_irqrestore(&tscadc->reg_lock, flags); 101 } 102 EXPORT_SYMBOL_GPL(am335x_tsc_se_clr); 103 104 static void tscadc_idle_config(struct ti_tscadc_dev *tscadc) 105 { 106 unsigned int idleconfig; 107 108 idleconfig = STEPCONFIG_INM_ADCREFM | STEPCONFIG_INP_ADCREFM; 109 if (ti_adc_with_touchscreen(tscadc)) 110 idleconfig |= STEPCONFIG_YNN | STEPCONFIG_YPN; 111 112 regmap_write(tscadc->regmap, REG_IDLECONFIG, idleconfig); 113 } 114 115 static int ti_tscadc_probe(struct platform_device *pdev) 116 { 117 struct ti_tscadc_dev *tscadc; 118 struct resource *res; 119 struct clk *clk; 120 struct device_node *node; 121 struct mfd_cell *cell; 122 bool use_tsc = false, use_mag = false; 123 u32 val; 124 int err; 125 int tscmag_wires = 0, adc_channels = 0, cell_idx = 0, total_channels; 126 int readouts = 0, mag_tracks = 0; 127 128 /* Allocate memory for device */ 129 tscadc = devm_kzalloc(&pdev->dev, sizeof(*tscadc), GFP_KERNEL); 130 if (!tscadc) 131 return -ENOMEM; 132 133 tscadc->dev = &pdev->dev; 134 135 if (!pdev->dev.of_node) { 136 dev_err(&pdev->dev, "Could not find valid DT data.\n"); 137 return -EINVAL; 138 } 139 140 tscadc->data = of_device_get_match_data(&pdev->dev); 141 142 if (ti_adc_with_touchscreen(tscadc)) { 143 node = of_get_child_by_name(pdev->dev.of_node, "tsc"); 144 of_property_read_u32(node, "ti,wires", &tscmag_wires); 145 err = of_property_read_u32(node, "ti,coordinate-readouts", 146 &readouts); 147 if (err < 0) 148 of_property_read_u32(node, "ti,coordiante-readouts", 149 &readouts); 150 151 of_node_put(node); 152 153 if (tscmag_wires) 154 use_tsc = true; 155 } else { 156 /* 157 * When adding support for the magnetic stripe reader, here is 158 * the place to look for the number of tracks used from device 159 * tree. Let's default to 0 for now. 160 */ 161 mag_tracks = 0; 162 tscmag_wires = mag_tracks * 2; 163 if (tscmag_wires) 164 use_mag = true; 165 } 166 167 node = of_get_child_by_name(pdev->dev.of_node, "adc"); 168 of_property_for_each_u32(node, "ti,adc-channels", val) { 169 adc_channels++; 170 if (val > 7) { 171 dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n", 172 val); 173 of_node_put(node); 174 return -EINVAL; 175 } 176 } 177 178 of_node_put(node); 179 180 total_channels = tscmag_wires + adc_channels; 181 if (total_channels > 8) { 182 dev_err(&pdev->dev, "Number of i/p channels more than 8\n"); 183 return -EINVAL; 184 } 185 186 if (total_channels == 0) { 187 dev_err(&pdev->dev, "Need at least one channel.\n"); 188 return -EINVAL; 189 } 190 191 if (use_tsc && (readouts * 2 + 2 + adc_channels > 16)) { 192 dev_err(&pdev->dev, "Too many step configurations requested\n"); 193 return -EINVAL; 194 } 195 196 err = platform_get_irq(pdev, 0); 197 if (err < 0) 198 return err; 199 else 200 tscadc->irq = err; 201 202 tscadc->tscadc_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 203 if (IS_ERR(tscadc->tscadc_base)) 204 return PTR_ERR(tscadc->tscadc_base); 205 206 tscadc->tscadc_phys_base = res->start; 207 tscadc->regmap = devm_regmap_init_mmio(&pdev->dev, 208 tscadc->tscadc_base, 209 &tscadc_regmap_config); 210 if (IS_ERR(tscadc->regmap)) { 211 dev_err(&pdev->dev, "regmap init failed\n"); 212 return PTR_ERR(tscadc->regmap); 213 } 214 215 spin_lock_init(&tscadc->reg_lock); 216 init_waitqueue_head(&tscadc->reg_se_wait); 217 218 pm_runtime_enable(&pdev->dev); 219 pm_runtime_get_sync(&pdev->dev); 220 221 /* 222 * The TSC_ADC_Subsystem has 2 clock domains: OCP_CLK and ADC_CLK. 223 * ADCs produce a 12-bit sample every 15 ADC_CLK cycles. 224 * am33xx ADCs expect to capture 200ksps. 225 * am47xx ADCs expect to capture 867ksps. 226 * We need ADC clocks respectively running at 3MHz and 13MHz. 227 * These frequencies are valid since TSC_ADC_SS controller design 228 * assumes the OCP clock is at least 6x faster than the ADC clock. 229 */ 230 clk = devm_clk_get(&pdev->dev, NULL); 231 if (IS_ERR(clk)) { 232 dev_err(&pdev->dev, "failed to get fck\n"); 233 err = PTR_ERR(clk); 234 goto err_disable_clk; 235 } 236 237 tscadc->clk_div = (clk_get_rate(clk) / tscadc->data->target_clk_rate) - 1; 238 regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div); 239 240 /* 241 * Set the control register bits. tscadc->ctrl stores the configuration 242 * of the CTRL register but not the subsystem enable bit which must be 243 * added manually when timely. 244 */ 245 tscadc->ctrl = CNTRLREG_STEPID; 246 if (ti_adc_with_touchscreen(tscadc)) { 247 tscadc->ctrl |= CNTRLREG_TSC_STEPCONFIGWRT; 248 if (use_tsc) { 249 tscadc->ctrl |= CNTRLREG_TSC_ENB; 250 if (tscmag_wires == 5) 251 tscadc->ctrl |= CNTRLREG_TSC_5WIRE; 252 else 253 tscadc->ctrl |= CNTRLREG_TSC_4WIRE; 254 } 255 } else { 256 tscadc->ctrl |= CNTRLREG_MAG_PREAMP_PWRDOWN | 257 CNTRLREG_MAG_PREAMP_BYPASS; 258 } 259 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl); 260 261 tscadc_idle_config(tscadc); 262 263 /* Enable the TSC module enable bit */ 264 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl | CNTRLREG_SSENB); 265 266 /* TSC or MAG Cell */ 267 if (use_tsc || use_mag) { 268 cell = &tscadc->cells[cell_idx++]; 269 cell->name = tscadc->data->secondary_feature_name; 270 cell->of_compatible = tscadc->data->secondary_feature_compatible; 271 cell->platform_data = &tscadc; 272 cell->pdata_size = sizeof(tscadc); 273 } 274 275 /* ADC Cell */ 276 if (adc_channels > 0) { 277 cell = &tscadc->cells[cell_idx++]; 278 cell->name = tscadc->data->adc_feature_name; 279 cell->of_compatible = tscadc->data->adc_feature_compatible; 280 cell->platform_data = &tscadc; 281 cell->pdata_size = sizeof(tscadc); 282 } 283 284 err = mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, 285 tscadc->cells, cell_idx, NULL, 0, NULL); 286 if (err < 0) 287 goto err_disable_clk; 288 289 platform_set_drvdata(pdev, tscadc); 290 return 0; 291 292 err_disable_clk: 293 pm_runtime_put_sync(&pdev->dev); 294 pm_runtime_disable(&pdev->dev); 295 296 return err; 297 } 298 299 static void ti_tscadc_remove(struct platform_device *pdev) 300 { 301 struct ti_tscadc_dev *tscadc = platform_get_drvdata(pdev); 302 303 regmap_write(tscadc->regmap, REG_SE, 0x00); 304 305 pm_runtime_put_sync(&pdev->dev); 306 pm_runtime_disable(&pdev->dev); 307 308 mfd_remove_devices(tscadc->dev); 309 } 310 311 static int __maybe_unused ti_tscadc_can_wakeup(struct device *dev, void *data) 312 { 313 return device_may_wakeup(dev); 314 } 315 316 static int __maybe_unused tscadc_suspend(struct device *dev) 317 { 318 struct ti_tscadc_dev *tscadc = dev_get_drvdata(dev); 319 320 regmap_write(tscadc->regmap, REG_SE, 0x00); 321 if (device_for_each_child(dev, NULL, ti_tscadc_can_wakeup)) { 322 u32 ctrl; 323 324 regmap_read(tscadc->regmap, REG_CTRL, &ctrl); 325 ctrl &= ~(CNTRLREG_POWERDOWN); 326 ctrl |= CNTRLREG_SSENB; 327 regmap_write(tscadc->regmap, REG_CTRL, ctrl); 328 } 329 pm_runtime_put_sync(dev); 330 331 return 0; 332 } 333 334 static int __maybe_unused tscadc_resume(struct device *dev) 335 { 336 struct ti_tscadc_dev *tscadc = dev_get_drvdata(dev); 337 338 pm_runtime_get_sync(dev); 339 340 regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div); 341 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl); 342 tscadc_idle_config(tscadc); 343 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl | CNTRLREG_SSENB); 344 345 return 0; 346 } 347 348 static SIMPLE_DEV_PM_OPS(tscadc_pm_ops, tscadc_suspend, tscadc_resume); 349 350 static const struct ti_tscadc_data tscdata = { 351 .adc_feature_name = "TI-am335x-adc", 352 .adc_feature_compatible = "ti,am3359-adc", 353 .secondary_feature_name = "TI-am335x-tsc", 354 .secondary_feature_compatible = "ti,am3359-tsc", 355 .target_clk_rate = TSC_ADC_CLK, 356 }; 357 358 static const struct ti_tscadc_data magdata = { 359 .adc_feature_name = "TI-am43xx-adc", 360 .adc_feature_compatible = "ti,am4372-adc", 361 .secondary_feature_name = "TI-am43xx-mag", 362 .secondary_feature_compatible = "ti,am4372-mag", 363 .target_clk_rate = MAG_ADC_CLK, 364 }; 365 366 static const struct of_device_id ti_tscadc_dt_ids[] = { 367 { .compatible = "ti,am3359-tscadc", .data = &tscdata }, 368 { .compatible = "ti,am4372-magadc", .data = &magdata }, 369 { } 370 }; 371 MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids); 372 373 static struct platform_driver ti_tscadc_driver = { 374 .driver = { 375 .name = "ti_am3359-tscadc", 376 .pm = &tscadc_pm_ops, 377 .of_match_table = ti_tscadc_dt_ids, 378 }, 379 .probe = ti_tscadc_probe, 380 .remove = ti_tscadc_remove, 381 382 }; 383 384 module_platform_driver(ti_tscadc_driver); 385 386 MODULE_DESCRIPTION("TI touchscreen/magnetic stripe reader/ADC MFD controller driver"); 387 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>"); 388 MODULE_LICENSE("GPL"); 389