1/* 2 * Atmel Touch Screen Driver 3 * 4 * Copyright (c) 2008 ATMEL 5 * Copyright (c) 2008 Dan Liang 6 * Copyright (c) 2008 TimeSys Corporation 7 * Copyright (c) 2008 Justin Waters 8 * 9 * Based on touchscreen code from Atmel Corporation. 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 */ 15#include <linux/init.h> 16#include <linux/err.h> 17#include <linux/kernel.h> 18#include <linux/module.h> 19#include <linux/input.h> 20#include <linux/slab.h> 21#include <linux/interrupt.h> 22#include <linux/clk.h> 23#include <linux/platform_device.h> 24#include <linux/io.h> 25#include <mach/board.h> 26#include <mach/cpu.h> 27 28/* Register definitions based on AT91SAM9RL64 preliminary draft datasheet */ 29 30#define ATMEL_TSADCC_CR 0x00 /* Control register */ 31#define ATMEL_TSADCC_SWRST (1 << 0) /* Software Reset*/ 32#define ATMEL_TSADCC_START (1 << 1) /* Start conversion */ 33 34#define ATMEL_TSADCC_MR 0x04 /* Mode register */ 35#define ATMEL_TSADCC_TSAMOD (3 << 0) /* ADC mode */ 36#define ATMEL_TSADCC_TSAMOD_ADC_ONLY_MODE (0x0) /* ADC Mode */ 37#define ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE (0x1) /* Touch Screen Only Mode */ 38#define ATMEL_TSADCC_LOWRES (1 << 4) /* Resolution selection */ 39#define ATMEL_TSADCC_SLEEP (1 << 5) /* Sleep mode */ 40#define ATMEL_TSADCC_PENDET (1 << 6) /* Pen Detect selection */ 41#define ATMEL_TSADCC_PRES (1 << 7) /* Pressure Measurement Selection */ 42#define ATMEL_TSADCC_PRESCAL (0x3f << 8) /* Prescalar Rate Selection */ 43#define ATMEL_TSADCC_EPRESCAL (0xff << 8) /* Prescalar Rate Selection (Extended) */ 44#define ATMEL_TSADCC_STARTUP (0x7f << 16) /* Start Up time */ 45#define ATMEL_TSADCC_SHTIM (0xf << 24) /* Sample & Hold time */ 46#define ATMEL_TSADCC_PENDBC (0xf << 28) /* Pen Detect debouncing time */ 47 48#define ATMEL_TSADCC_TRGR 0x08 /* Trigger register */ 49#define ATMEL_TSADCC_TRGMOD (7 << 0) /* Trigger mode */ 50#define ATMEL_TSADCC_TRGMOD_NONE (0 << 0) 51#define ATMEL_TSADCC_TRGMOD_EXT_RISING (1 << 0) 52#define ATMEL_TSADCC_TRGMOD_EXT_FALLING (2 << 0) 53#define ATMEL_TSADCC_TRGMOD_EXT_ANY (3 << 0) 54#define ATMEL_TSADCC_TRGMOD_PENDET (4 << 0) 55#define ATMEL_TSADCC_TRGMOD_PERIOD (5 << 0) 56#define ATMEL_TSADCC_TRGMOD_CONTINUOUS (6 << 0) 57#define ATMEL_TSADCC_TRGPER (0xffff << 16) /* Trigger period */ 58 59#define ATMEL_TSADCC_TSR 0x0C /* Touch Screen register */ 60#define ATMEL_TSADCC_TSFREQ (0xf << 0) /* TS Frequency in Interleaved mode */ 61#define ATMEL_TSADCC_TSSHTIM (0xf << 24) /* Sample & Hold time */ 62 63#define ATMEL_TSADCC_CHER 0x10 /* Channel Enable register */ 64#define ATMEL_TSADCC_CHDR 0x14 /* Channel Disable register */ 65#define ATMEL_TSADCC_CHSR 0x18 /* Channel Status register */ 66#define ATMEL_TSADCC_CH(n) (1 << (n)) /* Channel number */ 67 68#define ATMEL_TSADCC_SR 0x1C /* Status register */ 69#define ATMEL_TSADCC_EOC(n) (1 << ((n)+0)) /* End of conversion for channel N */ 70#define ATMEL_TSADCC_OVRE(n) (1 << ((n)+8)) /* Overrun error for channel N */ 71#define ATMEL_TSADCC_DRDY (1 << 16) /* Data Ready */ 72#define ATMEL_TSADCC_GOVRE (1 << 17) /* General Overrun Error */ 73#define ATMEL_TSADCC_ENDRX (1 << 18) /* End of RX Buffer */ 74#define ATMEL_TSADCC_RXBUFF (1 << 19) /* TX Buffer full */ 75#define ATMEL_TSADCC_PENCNT (1 << 20) /* Pen contact */ 76#define ATMEL_TSADCC_NOCNT (1 << 21) /* No contact */ 77 78#define ATMEL_TSADCC_LCDR 0x20 /* Last Converted Data register */ 79#define ATMEL_TSADCC_DATA (0x3ff << 0) /* Channel data */ 80 81#define ATMEL_TSADCC_IER 0x24 /* Interrupt Enable register */ 82#define ATMEL_TSADCC_IDR 0x28 /* Interrupt Disable register */ 83#define ATMEL_TSADCC_IMR 0x2C /* Interrupt Mask register */ 84#define ATMEL_TSADCC_CDR0 0x30 /* Channel Data 0 */ 85#define ATMEL_TSADCC_CDR1 0x34 /* Channel Data 1 */ 86#define ATMEL_TSADCC_CDR2 0x38 /* Channel Data 2 */ 87#define ATMEL_TSADCC_CDR3 0x3C /* Channel Data 3 */ 88#define ATMEL_TSADCC_CDR4 0x40 /* Channel Data 4 */ 89#define ATMEL_TSADCC_CDR5 0x44 /* Channel Data 5 */ 90 91#define ATMEL_TSADCC_XPOS 0x50 92#define ATMEL_TSADCC_Z1DAT 0x54 93#define ATMEL_TSADCC_Z2DAT 0x58 94 95#define PRESCALER_VAL(x) ((x) >> 8) 96 97#define ADC_DEFAULT_CLOCK 100000 98 99struct atmel_tsadcc { 100 struct input_dev *input; 101 char phys[32]; 102 struct clk *clk; 103 int irq; 104 unsigned int prev_absx; 105 unsigned int prev_absy; 106 unsigned char bufferedmeasure; 107}; 108 109static void __iomem *tsc_base; 110 111#define atmel_tsadcc_read(reg) __raw_readl(tsc_base + (reg)) 112#define atmel_tsadcc_write(reg, val) __raw_writel((val), tsc_base + (reg)) 113 114static irqreturn_t atmel_tsadcc_interrupt(int irq, void *dev) 115{ 116 struct atmel_tsadcc *ts_dev = (struct atmel_tsadcc *)dev; 117 struct input_dev *input_dev = ts_dev->input; 118 119 unsigned int status; 120 unsigned int reg; 121 122 status = atmel_tsadcc_read(ATMEL_TSADCC_SR); 123 status &= atmel_tsadcc_read(ATMEL_TSADCC_IMR); 124 125 if (status & ATMEL_TSADCC_NOCNT) { 126 /* Contact lost */ 127 reg = atmel_tsadcc_read(ATMEL_TSADCC_MR) | ATMEL_TSADCC_PENDBC; 128 129 atmel_tsadcc_write(ATMEL_TSADCC_MR, reg); 130 atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE); 131 atmel_tsadcc_write(ATMEL_TSADCC_IDR, 132 ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT); 133 atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT); 134 135 input_report_key(input_dev, BTN_TOUCH, 0); 136 ts_dev->bufferedmeasure = 0; 137 input_sync(input_dev); 138 139 } else if (status & ATMEL_TSADCC_PENCNT) { 140 /* Pen detected */ 141 reg = atmel_tsadcc_read(ATMEL_TSADCC_MR); 142 reg &= ~ATMEL_TSADCC_PENDBC; 143 144 atmel_tsadcc_write(ATMEL_TSADCC_IDR, ATMEL_TSADCC_PENCNT); 145 atmel_tsadcc_write(ATMEL_TSADCC_MR, reg); 146 atmel_tsadcc_write(ATMEL_TSADCC_IER, 147 ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT); 148 atmel_tsadcc_write(ATMEL_TSADCC_TRGR, 149 ATMEL_TSADCC_TRGMOD_PERIOD | (0x0FFF << 16)); 150 151 } else if (status & ATMEL_TSADCC_EOC(3)) { 152 /* Conversion finished */ 153 154 if (ts_dev->bufferedmeasure) { 155 /* Last measurement is always discarded, since it can 156 * be erroneous. 157 * Always report previous measurement */ 158 input_report_abs(input_dev, ABS_X, ts_dev->prev_absx); 159 input_report_abs(input_dev, ABS_Y, ts_dev->prev_absy); 160 input_report_key(input_dev, BTN_TOUCH, 1); 161 input_sync(input_dev); 162 } else 163 ts_dev->bufferedmeasure = 1; 164 165 /* Now make new measurement */ 166 ts_dev->prev_absx = atmel_tsadcc_read(ATMEL_TSADCC_CDR3) << 10; 167 ts_dev->prev_absx /= atmel_tsadcc_read(ATMEL_TSADCC_CDR2); 168 169 ts_dev->prev_absy = atmel_tsadcc_read(ATMEL_TSADCC_CDR1) << 10; 170 ts_dev->prev_absy /= atmel_tsadcc_read(ATMEL_TSADCC_CDR0); 171 } 172 173 return IRQ_HANDLED; 174} 175 176/* 177 * The functions for inserting/removing us as a module. 178 */ 179 180static int __devinit atmel_tsadcc_probe(struct platform_device *pdev) 181{ 182 struct atmel_tsadcc *ts_dev; 183 struct input_dev *input_dev; 184 struct resource *res; 185 struct at91_tsadcc_data *pdata = pdev->dev.platform_data; 186 int err = 0; 187 unsigned int prsc; 188 unsigned int reg; 189 190 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 191 if (!res) { 192 dev_err(&pdev->dev, "no mmio resource defined.\n"); 193 return -ENXIO; 194 } 195 196 /* Allocate memory for device */ 197 ts_dev = kzalloc(sizeof(struct atmel_tsadcc), GFP_KERNEL); 198 if (!ts_dev) { 199 dev_err(&pdev->dev, "failed to allocate memory.\n"); 200 return -ENOMEM; 201 } 202 platform_set_drvdata(pdev, ts_dev); 203 204 input_dev = input_allocate_device(); 205 if (!input_dev) { 206 dev_err(&pdev->dev, "failed to allocate input device.\n"); 207 err = -EBUSY; 208 goto err_free_mem; 209 } 210 211 ts_dev->irq = platform_get_irq(pdev, 0); 212 if (ts_dev->irq < 0) { 213 dev_err(&pdev->dev, "no irq ID is designated.\n"); 214 err = -ENODEV; 215 goto err_free_dev; 216 } 217 218 if (!request_mem_region(res->start, resource_size(res), 219 "atmel tsadcc regs")) { 220 dev_err(&pdev->dev, "resources is unavailable.\n"); 221 err = -EBUSY; 222 goto err_free_dev; 223 } 224 225 tsc_base = ioremap(res->start, resource_size(res)); 226 if (!tsc_base) { 227 dev_err(&pdev->dev, "failed to map registers.\n"); 228 err = -ENOMEM; 229 goto err_release_mem; 230 } 231 232 err = request_irq(ts_dev->irq, atmel_tsadcc_interrupt, IRQF_DISABLED, 233 pdev->dev.driver->name, ts_dev); 234 if (err) { 235 dev_err(&pdev->dev, "failed to allocate irq.\n"); 236 goto err_unmap_regs; 237 } 238 239 ts_dev->clk = clk_get(&pdev->dev, "tsc_clk"); 240 if (IS_ERR(ts_dev->clk)) { 241 dev_err(&pdev->dev, "failed to get ts_clk\n"); 242 err = PTR_ERR(ts_dev->clk); 243 goto err_free_irq; 244 } 245 246 ts_dev->input = input_dev; 247 ts_dev->bufferedmeasure = 0; 248 249 snprintf(ts_dev->phys, sizeof(ts_dev->phys), 250 "%s/input0", dev_name(&pdev->dev)); 251 252 input_dev->name = "atmel touch screen controller"; 253 input_dev->phys = ts_dev->phys; 254 input_dev->dev.parent = &pdev->dev; 255 256 __set_bit(EV_ABS, input_dev->evbit); 257 input_set_abs_params(input_dev, ABS_X, 0, 0x3FF, 0, 0); 258 input_set_abs_params(input_dev, ABS_Y, 0, 0x3FF, 0, 0); 259 260 input_set_capability(input_dev, EV_KEY, BTN_TOUCH); 261 262 /* clk_enable() always returns 0, no need to check it */ 263 clk_enable(ts_dev->clk); 264 265 prsc = clk_get_rate(ts_dev->clk); 266 dev_info(&pdev->dev, "Master clock is set at: %d Hz\n", prsc); 267 268 if (!pdata) 269 goto err_fail; 270 271 if (!pdata->adc_clock) 272 pdata->adc_clock = ADC_DEFAULT_CLOCK; 273 274 prsc = (prsc / (2 * pdata->adc_clock)) - 1; 275 276 /* saturate if this value is too high */ 277 if (cpu_is_at91sam9rl()) { 278 if (prsc > PRESCALER_VAL(ATMEL_TSADCC_PRESCAL)) 279 prsc = PRESCALER_VAL(ATMEL_TSADCC_PRESCAL); 280 } else { 281 if (prsc > PRESCALER_VAL(ATMEL_TSADCC_EPRESCAL)) 282 prsc = PRESCALER_VAL(ATMEL_TSADCC_EPRESCAL); 283 } 284 285 dev_info(&pdev->dev, "Prescaler is set at: %d\n", prsc); 286 287 reg = ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE | 288 ((0x00 << 5) & ATMEL_TSADCC_SLEEP) | /* Normal Mode */ 289 ((0x01 << 6) & ATMEL_TSADCC_PENDET) | /* Enable Pen Detect */ 290 (prsc << 8) | 291 ((0x26 << 16) & ATMEL_TSADCC_STARTUP) | 292 ((pdata->pendet_debounce << 28) & ATMEL_TSADCC_PENDBC); 293 294 atmel_tsadcc_write(ATMEL_TSADCC_CR, ATMEL_TSADCC_SWRST); 295 atmel_tsadcc_write(ATMEL_TSADCC_MR, reg); 296 atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE); 297 atmel_tsadcc_write(ATMEL_TSADCC_TSR, 298 (pdata->ts_sample_hold_time << 24) & ATMEL_TSADCC_TSSHTIM); 299 300 atmel_tsadcc_read(ATMEL_TSADCC_SR); 301 atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT); 302 303 /* All went ok, so register to the input system */ 304 err = input_register_device(input_dev); 305 if (err) 306 goto err_fail; 307 308 return 0; 309 310err_fail: 311 clk_disable(ts_dev->clk); 312 clk_put(ts_dev->clk); 313err_free_irq: 314 free_irq(ts_dev->irq, ts_dev); 315err_unmap_regs: 316 iounmap(tsc_base); 317err_release_mem: 318 release_mem_region(res->start, resource_size(res)); 319err_free_dev: 320 input_free_device(ts_dev->input); 321err_free_mem: 322 kfree(ts_dev); 323 return err; 324} 325 326static int __devexit atmel_tsadcc_remove(struct platform_device *pdev) 327{ 328 struct atmel_tsadcc *ts_dev = dev_get_drvdata(&pdev->dev); 329 struct resource *res; 330 331 free_irq(ts_dev->irq, ts_dev); 332 333 input_unregister_device(ts_dev->input); 334 335 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 336 iounmap(tsc_base); 337 release_mem_region(res->start, resource_size(res)); 338 339 clk_disable(ts_dev->clk); 340 clk_put(ts_dev->clk); 341 342 kfree(ts_dev); 343 344 return 0; 345} 346 347static struct platform_driver atmel_tsadcc_driver = { 348 .probe = atmel_tsadcc_probe, 349 .remove = __devexit_p(atmel_tsadcc_remove), 350 .driver = { 351 .name = "atmel_tsadcc", 352 }, 353}; 354 355static int __init atmel_tsadcc_init(void) 356{ 357 return platform_driver_register(&atmel_tsadcc_driver); 358} 359 360static void __exit atmel_tsadcc_exit(void) 361{ 362 platform_driver_unregister(&atmel_tsadcc_driver); 363} 364 365module_init(atmel_tsadcc_init); 366module_exit(atmel_tsadcc_exit); 367 368 369MODULE_LICENSE("GPL"); 370MODULE_DESCRIPTION("Atmel TouchScreen Driver"); 371MODULE_AUTHOR("Dan Liang <dan.liang@atmel.com>"); 372