Cyril Chemparathy | 0fa6c77 | 2010-09-20 12:26:43 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Texas Instruments TNETV107X Touchscreen Driver |
| 3 | * |
| 4 | * Copyright (C) 2010 Texas Instruments |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License as |
| 8 | * published by the Free Software Foundation version 2. |
| 9 | * |
| 10 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any |
| 11 | * kind, whether express or implied; without even the implied warranty |
| 12 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/errno.h> |
| 18 | #include <linux/input.h> |
| 19 | #include <linux/platform_device.h> |
| 20 | #include <linux/interrupt.h> |
| 21 | #include <linux/slab.h> |
| 22 | #include <linux/delay.h> |
| 23 | #include <linux/ctype.h> |
| 24 | #include <linux/io.h> |
| 25 | #include <linux/clk.h> |
| 26 | |
| 27 | #include <mach/tnetv107x.h> |
| 28 | |
| 29 | #define TSC_PENUP_POLL (HZ / 5) |
| 30 | #define IDLE_TIMEOUT 100 /* msec */ |
| 31 | |
| 32 | /* |
| 33 | * The first and last samples of a touch interval are usually garbage and need |
| 34 | * to be filtered out with these devices. The following definitions control |
| 35 | * the number of samples skipped. |
| 36 | */ |
| 37 | #define TSC_HEAD_SKIP 1 |
| 38 | #define TSC_TAIL_SKIP 1 |
| 39 | #define TSC_SKIP (TSC_HEAD_SKIP + TSC_TAIL_SKIP + 1) |
| 40 | #define TSC_SAMPLES (TSC_SKIP + 1) |
| 41 | |
| 42 | /* Register Offsets */ |
| 43 | struct tsc_regs { |
| 44 | u32 rev; |
| 45 | u32 tscm; |
| 46 | u32 bwcm; |
| 47 | u32 swc; |
| 48 | u32 adcchnl; |
| 49 | u32 adcdata; |
| 50 | u32 chval[4]; |
| 51 | }; |
| 52 | |
| 53 | /* TSC Mode Configuration Register (tscm) bits */ |
| 54 | #define WMODE BIT(0) |
| 55 | #define TSKIND BIT(1) |
| 56 | #define ZMEASURE_EN BIT(2) |
| 57 | #define IDLE BIT(3) |
| 58 | #define TSC_EN BIT(4) |
| 59 | #define STOP BIT(5) |
| 60 | #define ONE_SHOT BIT(6) |
| 61 | #define SINGLE BIT(7) |
| 62 | #define AVG BIT(8) |
| 63 | #define AVGNUM(x) (((x) & 0x03) << 9) |
| 64 | #define PVSTC(x) (((x) & 0x07) << 11) |
| 65 | #define PON BIT(14) |
| 66 | #define PONBG BIT(15) |
| 67 | #define AFERST BIT(16) |
| 68 | |
| 69 | /* ADC DATA Capture Register bits */ |
| 70 | #define DATA_VALID BIT(16) |
| 71 | |
| 72 | /* Register Access Macros */ |
| 73 | #define tsc_read(ts, reg) __raw_readl(&(ts)->regs->reg) |
| 74 | #define tsc_write(ts, reg, val) __raw_writel(val, &(ts)->regs->reg); |
| 75 | #define tsc_set_bits(ts, reg, val) \ |
| 76 | tsc_write(ts, reg, tsc_read(ts, reg) | (val)) |
| 77 | #define tsc_clr_bits(ts, reg, val) \ |
| 78 | tsc_write(ts, reg, tsc_read(ts, reg) & ~(val)) |
| 79 | |
| 80 | struct sample { |
| 81 | int x, y, p; |
| 82 | }; |
| 83 | |
| 84 | struct tsc_data { |
| 85 | struct input_dev *input_dev; |
| 86 | struct resource *res; |
| 87 | struct tsc_regs __iomem *regs; |
| 88 | struct timer_list timer; |
| 89 | spinlock_t lock; |
| 90 | struct clk *clk; |
| 91 | struct device *dev; |
| 92 | int sample_count; |
| 93 | struct sample samples[TSC_SAMPLES]; |
| 94 | int tsc_irq; |
| 95 | }; |
| 96 | |
| 97 | static int tsc_read_sample(struct tsc_data *ts, struct sample* sample) |
| 98 | { |
| 99 | int x, y, z1, z2, t, p = 0; |
| 100 | u32 val; |
| 101 | |
| 102 | val = tsc_read(ts, chval[0]); |
| 103 | if (val & DATA_VALID) |
| 104 | x = val & 0xffff; |
| 105 | else |
| 106 | return -EINVAL; |
| 107 | |
| 108 | y = tsc_read(ts, chval[1]) & 0xffff; |
| 109 | z1 = tsc_read(ts, chval[2]) & 0xffff; |
| 110 | z2 = tsc_read(ts, chval[3]) & 0xffff; |
| 111 | |
| 112 | if (z1) { |
| 113 | t = ((600 * x) * (z2 - z1)); |
| 114 | p = t / (u32) (z1 << 12); |
| 115 | if (p < 0) |
| 116 | p = 0; |
| 117 | } |
| 118 | |
| 119 | sample->x = x; |
| 120 | sample->y = y; |
| 121 | sample->p = p; |
| 122 | |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | static void tsc_poll(unsigned long data) |
| 127 | { |
| 128 | struct tsc_data *ts = (struct tsc_data *)data; |
| 129 | unsigned long flags; |
| 130 | int i, val, x, y, p; |
| 131 | |
| 132 | spin_lock_irqsave(&ts->lock, flags); |
| 133 | |
| 134 | if (ts->sample_count >= TSC_SKIP) { |
| 135 | input_report_abs(ts->input_dev, ABS_PRESSURE, 0); |
| 136 | input_report_key(ts->input_dev, BTN_TOUCH, 0); |
| 137 | input_sync(ts->input_dev); |
| 138 | } else if (ts->sample_count > 0) { |
| 139 | /* |
| 140 | * A touch event lasted less than our skip count. Salvage and |
| 141 | * report anyway. |
| 142 | */ |
| 143 | for (i = 0, val = 0; i < ts->sample_count; i++) |
| 144 | val += ts->samples[i].x; |
| 145 | x = val / ts->sample_count; |
| 146 | |
| 147 | for (i = 0, val = 0; i < ts->sample_count; i++) |
| 148 | val += ts->samples[i].y; |
| 149 | y = val / ts->sample_count; |
| 150 | |
| 151 | for (i = 0, val = 0; i < ts->sample_count; i++) |
| 152 | val += ts->samples[i].p; |
| 153 | p = val / ts->sample_count; |
| 154 | |
| 155 | input_report_abs(ts->input_dev, ABS_X, x); |
| 156 | input_report_abs(ts->input_dev, ABS_Y, y); |
| 157 | input_report_abs(ts->input_dev, ABS_PRESSURE, p); |
| 158 | input_report_key(ts->input_dev, BTN_TOUCH, 1); |
| 159 | input_sync(ts->input_dev); |
| 160 | } |
| 161 | |
| 162 | ts->sample_count = 0; |
| 163 | |
| 164 | spin_unlock_irqrestore(&ts->lock, flags); |
| 165 | } |
| 166 | |
| 167 | static irqreturn_t tsc_irq(int irq, void *dev_id) |
| 168 | { |
| 169 | struct tsc_data *ts = (struct tsc_data *)dev_id; |
| 170 | struct sample *sample; |
| 171 | int index; |
| 172 | |
| 173 | spin_lock(&ts->lock); |
| 174 | |
| 175 | index = ts->sample_count % TSC_SAMPLES; |
| 176 | sample = &ts->samples[index]; |
| 177 | if (tsc_read_sample(ts, sample) < 0) |
| 178 | goto out; |
| 179 | |
| 180 | if (++ts->sample_count >= TSC_SKIP) { |
| 181 | index = (ts->sample_count - TSC_TAIL_SKIP - 1) % TSC_SAMPLES; |
| 182 | sample = &ts->samples[index]; |
| 183 | |
| 184 | input_report_abs(ts->input_dev, ABS_X, sample->x); |
| 185 | input_report_abs(ts->input_dev, ABS_Y, sample->y); |
| 186 | input_report_abs(ts->input_dev, ABS_PRESSURE, sample->p); |
| 187 | if (ts->sample_count == TSC_SKIP) |
| 188 | input_report_key(ts->input_dev, BTN_TOUCH, 1); |
| 189 | input_sync(ts->input_dev); |
| 190 | } |
| 191 | mod_timer(&ts->timer, jiffies + TSC_PENUP_POLL); |
| 192 | out: |
| 193 | spin_unlock(&ts->lock); |
| 194 | return IRQ_HANDLED; |
| 195 | } |
| 196 | |
| 197 | static int tsc_start(struct input_dev *dev) |
| 198 | { |
| 199 | struct tsc_data *ts = input_get_drvdata(dev); |
| 200 | unsigned long timeout = jiffies + msecs_to_jiffies(IDLE_TIMEOUT); |
| 201 | u32 val; |
| 202 | |
| 203 | clk_enable(ts->clk); |
| 204 | |
| 205 | /* Go to idle mode, before any initialization */ |
| 206 | while (time_after(timeout, jiffies)) { |
| 207 | if (tsc_read(ts, tscm) & IDLE) |
| 208 | break; |
| 209 | } |
| 210 | |
| 211 | if (time_before(timeout, jiffies)) { |
| 212 | dev_warn(ts->dev, "timeout waiting for idle\n"); |
| 213 | clk_disable(ts->clk); |
| 214 | return -EIO; |
| 215 | } |
| 216 | |
| 217 | /* Configure TSC Control register*/ |
| 218 | val = (PONBG | PON | PVSTC(4) | ONE_SHOT | ZMEASURE_EN); |
| 219 | tsc_write(ts, tscm, val); |
| 220 | |
| 221 | /* Bring TSC out of reset: Clear AFE reset bit */ |
| 222 | val &= ~(AFERST); |
| 223 | tsc_write(ts, tscm, val); |
| 224 | |
| 225 | /* Configure all pins for hardware control*/ |
| 226 | tsc_write(ts, bwcm, 0); |
| 227 | |
| 228 | /* Finally enable the TSC */ |
| 229 | tsc_set_bits(ts, tscm, TSC_EN); |
| 230 | |
| 231 | return 0; |
| 232 | } |
| 233 | |
| 234 | static void tsc_stop(struct input_dev *dev) |
| 235 | { |
| 236 | struct tsc_data *ts = input_get_drvdata(dev); |
| 237 | |
| 238 | tsc_clr_bits(ts, tscm, TSC_EN); |
| 239 | synchronize_irq(ts->tsc_irq); |
| 240 | del_timer_sync(&ts->timer); |
| 241 | clk_disable(ts->clk); |
| 242 | } |
| 243 | |
| 244 | static int __devinit tsc_probe(struct platform_device *pdev) |
| 245 | { |
| 246 | struct device *dev = &pdev->dev; |
| 247 | struct tsc_data *ts; |
| 248 | int error = 0; |
| 249 | u32 rev = 0; |
| 250 | |
| 251 | ts = kzalloc(sizeof(struct tsc_data), GFP_KERNEL); |
| 252 | if (!ts) { |
| 253 | dev_err(dev, "cannot allocate device info\n"); |
| 254 | return -ENOMEM; |
| 255 | } |
| 256 | |
| 257 | ts->dev = dev; |
| 258 | spin_lock_init(&ts->lock); |
| 259 | setup_timer(&ts->timer, tsc_poll, (unsigned long)ts); |
| 260 | platform_set_drvdata(pdev, ts); |
| 261 | |
| 262 | ts->tsc_irq = platform_get_irq(pdev, 0); |
| 263 | if (ts->tsc_irq < 0) { |
| 264 | dev_err(dev, "cannot determine device interrupt\n"); |
| 265 | error = -ENODEV; |
| 266 | goto error_res; |
| 267 | } |
| 268 | |
| 269 | ts->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 270 | if (!ts->res) { |
| 271 | dev_err(dev, "cannot determine register area\n"); |
| 272 | error = -ENODEV; |
| 273 | goto error_res; |
| 274 | } |
| 275 | |
| 276 | if (!request_mem_region(ts->res->start, resource_size(ts->res), |
| 277 | pdev->name)) { |
| 278 | dev_err(dev, "cannot claim register memory\n"); |
| 279 | ts->res = NULL; |
| 280 | error = -EINVAL; |
| 281 | goto error_res; |
| 282 | } |
| 283 | |
| 284 | ts->regs = ioremap(ts->res->start, resource_size(ts->res)); |
| 285 | if (!ts->regs) { |
| 286 | dev_err(dev, "cannot map register memory\n"); |
| 287 | error = -ENOMEM; |
| 288 | goto error_map; |
| 289 | } |
| 290 | |
| 291 | ts->clk = clk_get(dev, NULL); |
| 292 | if (!ts->clk) { |
| 293 | dev_err(dev, "cannot claim device clock\n"); |
| 294 | error = -EINVAL; |
| 295 | goto error_clk; |
| 296 | } |
| 297 | |
| 298 | error = request_threaded_irq(ts->tsc_irq, NULL, tsc_irq, 0, |
| 299 | dev_name(dev), ts); |
| 300 | if (error < 0) { |
| 301 | dev_err(ts->dev, "Could not allocate ts irq\n"); |
| 302 | goto error_irq; |
| 303 | } |
| 304 | |
| 305 | ts->input_dev = input_allocate_device(); |
| 306 | if (!ts->input_dev) { |
| 307 | dev_err(dev, "cannot allocate input device\n"); |
| 308 | error = -ENOMEM; |
| 309 | goto error_input; |
| 310 | } |
| 311 | input_set_drvdata(ts->input_dev, ts); |
| 312 | |
| 313 | ts->input_dev->name = pdev->name; |
| 314 | ts->input_dev->id.bustype = BUS_HOST; |
| 315 | ts->input_dev->dev.parent = &pdev->dev; |
| 316 | ts->input_dev->open = tsc_start; |
| 317 | ts->input_dev->close = tsc_stop; |
| 318 | |
| 319 | clk_enable(ts->clk); |
| 320 | rev = tsc_read(ts, rev); |
| 321 | ts->input_dev->id.product = ((rev >> 8) & 0x07); |
| 322 | ts->input_dev->id.version = ((rev >> 16) & 0xfff); |
| 323 | clk_disable(ts->clk); |
| 324 | |
| 325 | __set_bit(EV_KEY, ts->input_dev->evbit); |
| 326 | __set_bit(EV_ABS, ts->input_dev->evbit); |
| 327 | __set_bit(BTN_TOUCH, ts->input_dev->keybit); |
| 328 | |
| 329 | input_set_abs_params(ts->input_dev, ABS_X, 0, 0xffff, 5, 0); |
| 330 | input_set_abs_params(ts->input_dev, ABS_Y, 0, 0xffff, 5, 0); |
| 331 | input_set_abs_params(ts->input_dev, ABS_PRESSURE, 0, 4095, 128, 0); |
| 332 | |
| 333 | error = input_register_device(ts->input_dev); |
| 334 | if (error < 0) { |
| 335 | dev_err(dev, "failed input device registration\n"); |
| 336 | goto error_reg; |
| 337 | } |
| 338 | |
| 339 | return 0; |
| 340 | |
| 341 | error_reg: |
| 342 | input_free_device(ts->input_dev); |
| 343 | error_input: |
| 344 | free_irq(ts->tsc_irq, ts); |
| 345 | error_irq: |
| 346 | clk_put(ts->clk); |
| 347 | error_clk: |
| 348 | iounmap(ts->regs); |
| 349 | error_map: |
| 350 | release_mem_region(ts->res->start, resource_size(ts->res)); |
| 351 | error_res: |
| 352 | platform_set_drvdata(pdev, NULL); |
| 353 | kfree(ts); |
| 354 | |
| 355 | return error; |
| 356 | } |
| 357 | |
| 358 | static int __devexit tsc_remove(struct platform_device *pdev) |
| 359 | { |
| 360 | struct tsc_data *ts = platform_get_drvdata(pdev); |
| 361 | |
| 362 | input_unregister_device(ts->input_dev); |
| 363 | free_irq(ts->tsc_irq, ts); |
| 364 | clk_put(ts->clk); |
| 365 | iounmap(ts->regs); |
| 366 | release_mem_region(ts->res->start, resource_size(ts->res)); |
| 367 | platform_set_drvdata(pdev, NULL); |
| 368 | kfree(ts); |
| 369 | |
| 370 | return 0; |
| 371 | } |
| 372 | |
| 373 | static struct platform_driver tsc_driver = { |
| 374 | .probe = tsc_probe, |
| 375 | .remove = __devexit_p(tsc_remove), |
| 376 | .driver.name = "tnetv107x-ts", |
| 377 | .driver.owner = THIS_MODULE, |
| 378 | }; |
| 379 | |
| 380 | static int __init tsc_init(void) |
| 381 | { |
| 382 | return platform_driver_register(&tsc_driver); |
| 383 | } |
| 384 | |
| 385 | static void __exit tsc_exit(void) |
| 386 | { |
| 387 | platform_driver_unregister(&tsc_driver); |
| 388 | } |
| 389 | |
| 390 | module_init(tsc_init); |
| 391 | module_exit(tsc_exit); |
| 392 | |
| 393 | MODULE_AUTHOR("Cyril Chemparathy"); |
| 394 | MODULE_DESCRIPTION("TNETV107X Touchscreen Driver"); |
| 395 | MODULE_ALIAS("platform: tnetv107x-ts"); |
| 396 | MODULE_LICENSE("GPL"); |