389 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * TI Touch Screen / ADC MFD driver4 *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 22static 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 29void 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}42EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache);43 44static 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 or63 * 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 72void 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}80EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once);81 82void 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}91EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done);92 93void 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}102EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);103 104static 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 115static 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 is158 * the place to look for the number of tracks used from device159 * 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 else200 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 design228 * 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 configuration242 * of the CTRL register but not the subsystem enable bit which must be243 * 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 else253 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 292err_disable_clk:293 pm_runtime_put_sync(&pdev->dev);294 pm_runtime_disable(&pdev->dev);295 296 return err;297}298 299static 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 311static int __maybe_unused ti_tscadc_can_wakeup(struct device *dev, void *data)312{313 return device_may_wakeup(dev);314}315 316static 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 334static 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 348static SIMPLE_DEV_PM_OPS(tscadc_pm_ops, tscadc_suspend, tscadc_resume);349 350static 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 358static 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 366static 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};371MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);372 373static 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_new = ti_tscadc_remove,381 382};383 384module_platform_driver(ti_tscadc_driver);385 386MODULE_DESCRIPTION("TI touchscreen/magnetic stripe reader/ADC MFD controller driver");387MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");388MODULE_LICENSE("GPL");389