1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2013 STMicroelectronics Limited 4 * Author: Srinivas Kandagatla <srinivas.kandagatla@st.com> 5 */ 6 #include <linux/kernel.h> 7 #include <linux/clk.h> 8 #include <linux/interrupt.h> 9 #include <linux/module.h> 10 #include <linux/of.h> 11 #include <linux/platform_device.h> 12 #include <linux/reset.h> 13 #include <media/rc-core.h> 14 #include <linux/pinctrl/consumer.h> 15 #include <linux/pm_wakeirq.h> 16 17 struct st_rc_device { 18 struct device *dev; 19 int irq; 20 int irq_wake; 21 struct clk *sys_clock; 22 void __iomem *base; /* Register base address */ 23 void __iomem *rx_base;/* RX Register base address */ 24 struct rc_dev *rdev; 25 bool overclocking; 26 int sample_mult; 27 int sample_div; 28 bool rxuhfmode; 29 struct reset_control *rstc; 30 }; 31 32 /* Registers */ 33 #define IRB_SAMPLE_RATE_COMM 0x64 /* sample freq divisor*/ 34 #define IRB_CLOCK_SEL 0x70 /* clock select */ 35 #define IRB_CLOCK_SEL_STATUS 0x74 /* clock status */ 36 /* IRB IR/UHF receiver registers */ 37 #define IRB_RX_ON 0x40 /* pulse time capture */ 38 #define IRB_RX_SYS 0X44 /* sym period capture */ 39 #define IRB_RX_INT_EN 0x48 /* IRQ enable (R/W) */ 40 #define IRB_RX_INT_STATUS 0x4c /* IRQ status (R/W) */ 41 #define IRB_RX_EN 0x50 /* Receive enable */ 42 #define IRB_MAX_SYM_PERIOD 0x54 /* max sym value */ 43 #define IRB_RX_INT_CLEAR 0x58 /* overrun status */ 44 #define IRB_RX_STATUS 0x6c /* receive status */ 45 #define IRB_RX_NOISE_SUPPR 0x5c /* noise suppression */ 46 #define IRB_RX_POLARITY_INV 0x68 /* polarity inverter */ 47 48 /* 49 * IRQ set: Enable full FIFO 1 -> bit 3; 50 * Enable overrun IRQ 1 -> bit 2; 51 * Enable last symbol IRQ 1 -> bit 1: 52 * Enable RX interrupt 1 -> bit 0; 53 */ 54 #define IRB_RX_INTS 0x0f 55 #define IRB_RX_OVERRUN_INT 0x04 56 /* maximum symbol period (microsecs),timeout to detect end of symbol train */ 57 #define MAX_SYMB_TIME 0x5000 58 #define IRB_SAMPLE_FREQ 10000000 59 #define IRB_FIFO_NOT_EMPTY 0xff00 60 #define IRB_OVERFLOW 0x4 61 #define IRB_TIMEOUT 0xffff 62 #define IR_ST_NAME "st-rc" 63 64 static void st_rc_send_lirc_timeout(struct rc_dev *rdev) 65 { 66 struct ir_raw_event ev = { .timeout = true, .duration = rdev->timeout }; 67 ir_raw_event_store(rdev, &ev); 68 } 69 70 /* 71 * RX graphical example to better understand the difference between ST IR block 72 * output and standard definition used by LIRC (and most of the world!) 73 * 74 * mark mark 75 * |-IRB_RX_ON-| |-IRB_RX_ON-| 76 * ___ ___ ___ ___ ___ ___ _ 77 * | | | | | | | | | | | | | 78 * | | | | | | space 0 | | | | | | space 1 | 79 * _____| |__| |__| |____________________________| |__| |__| |_____________| 80 * 81 * |--------------- IRB_RX_SYS -------------|------ IRB_RX_SYS -------| 82 * 83 * |------------- encoding bit 0 -----------|---- encoding bit 1 -----| 84 * 85 * ST hardware returns mark (IRB_RX_ON) and total symbol time (IRB_RX_SYS), so 86 * convert to standard mark/space we have to calculate space=(IRB_RX_SYS-mark) 87 * The mark time represents the amount of time the carrier (usually 36-40kHz) 88 * is detected.The above examples shows Pulse Width Modulation encoding where 89 * bit 0 is represented by space>mark. 90 */ 91 92 static irqreturn_t st_rc_rx_interrupt(int irq, void *data) 93 { 94 unsigned long timeout; 95 unsigned int symbol, mark = 0; 96 struct st_rc_device *dev = data; 97 int last_symbol = 0; 98 u32 status, int_status; 99 struct ir_raw_event ev = {}; 100 101 if (dev->irq_wake) 102 pm_wakeup_event(dev->dev, 0); 103 104 /* FIXME: is 10ms good enough ? */ 105 timeout = jiffies + msecs_to_jiffies(10); 106 do { 107 status = readl(dev->rx_base + IRB_RX_STATUS); 108 if (!(status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW))) 109 break; 110 111 int_status = readl(dev->rx_base + IRB_RX_INT_STATUS); 112 if (unlikely(int_status & IRB_RX_OVERRUN_INT)) { 113 /* discard the entire collection in case of errors! */ 114 ir_raw_event_reset(dev->rdev); 115 dev_info(dev->dev, "IR RX overrun\n"); 116 writel(IRB_RX_OVERRUN_INT, 117 dev->rx_base + IRB_RX_INT_CLEAR); 118 continue; 119 } 120 121 symbol = readl(dev->rx_base + IRB_RX_SYS); 122 mark = readl(dev->rx_base + IRB_RX_ON); 123 124 if (symbol == IRB_TIMEOUT) 125 last_symbol = 1; 126 127 /* Ignore any noise */ 128 if ((mark > 2) && (symbol > 1)) { 129 symbol -= mark; 130 if (dev->overclocking) { /* adjustments to timings */ 131 symbol *= dev->sample_mult; 132 symbol /= dev->sample_div; 133 mark *= dev->sample_mult; 134 mark /= dev->sample_div; 135 } 136 137 ev.duration = US_TO_NS(mark); 138 ev.pulse = true; 139 ir_raw_event_store(dev->rdev, &ev); 140 141 if (!last_symbol) { 142 ev.duration = US_TO_NS(symbol); 143 ev.pulse = false; 144 ir_raw_event_store(dev->rdev, &ev); 145 } else { 146 st_rc_send_lirc_timeout(dev->rdev); 147 } 148 149 } 150 last_symbol = 0; 151 } while (time_is_after_jiffies(timeout)); 152 153 writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_CLEAR); 154 155 /* Empty software fifo */ 156 ir_raw_event_handle(dev->rdev); 157 return IRQ_HANDLED; 158 } 159 160 static void st_rc_hardware_init(struct st_rc_device *dev) 161 { 162 int baseclock, freqdiff; 163 unsigned int rx_max_symbol_per = MAX_SYMB_TIME; 164 unsigned int rx_sampling_freq_div; 165 166 /* Enable the IP */ 167 reset_control_deassert(dev->rstc); 168 169 clk_prepare_enable(dev->sys_clock); 170 baseclock = clk_get_rate(dev->sys_clock); 171 172 /* IRB input pins are inverted internally from high to low. */ 173 writel(1, dev->rx_base + IRB_RX_POLARITY_INV); 174 175 rx_sampling_freq_div = baseclock / IRB_SAMPLE_FREQ; 176 writel(rx_sampling_freq_div, dev->base + IRB_SAMPLE_RATE_COMM); 177 178 freqdiff = baseclock - (rx_sampling_freq_div * IRB_SAMPLE_FREQ); 179 if (freqdiff) { /* over clocking, workout the adjustment factors */ 180 dev->overclocking = true; 181 dev->sample_mult = 1000; 182 dev->sample_div = baseclock / (10000 * rx_sampling_freq_div); 183 rx_max_symbol_per = (rx_max_symbol_per * 1000)/dev->sample_div; 184 } 185 186 writel(rx_max_symbol_per, dev->rx_base + IRB_MAX_SYM_PERIOD); 187 } 188 189 static int st_rc_remove(struct platform_device *pdev) 190 { 191 struct st_rc_device *rc_dev = platform_get_drvdata(pdev); 192 193 dev_pm_clear_wake_irq(&pdev->dev); 194 device_init_wakeup(&pdev->dev, false); 195 clk_disable_unprepare(rc_dev->sys_clock); 196 rc_unregister_device(rc_dev->rdev); 197 return 0; 198 } 199 200 static int st_rc_open(struct rc_dev *rdev) 201 { 202 struct st_rc_device *dev = rdev->priv; 203 unsigned long flags; 204 local_irq_save(flags); 205 /* enable interrupts and receiver */ 206 writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_EN); 207 writel(0x01, dev->rx_base + IRB_RX_EN); 208 local_irq_restore(flags); 209 210 return 0; 211 } 212 213 static void st_rc_close(struct rc_dev *rdev) 214 { 215 struct st_rc_device *dev = rdev->priv; 216 /* disable interrupts and receiver */ 217 writel(0x00, dev->rx_base + IRB_RX_EN); 218 writel(0x00, dev->rx_base + IRB_RX_INT_EN); 219 } 220 221 static int st_rc_probe(struct platform_device *pdev) 222 { 223 int ret = -EINVAL; 224 struct rc_dev *rdev; 225 struct device *dev = &pdev->dev; 226 struct resource *res; 227 struct st_rc_device *rc_dev; 228 struct device_node *np = pdev->dev.of_node; 229 const char *rx_mode; 230 231 rc_dev = devm_kzalloc(dev, sizeof(struct st_rc_device), GFP_KERNEL); 232 233 if (!rc_dev) 234 return -ENOMEM; 235 236 rdev = rc_allocate_device(RC_DRIVER_IR_RAW); 237 238 if (!rdev) 239 return -ENOMEM; 240 241 if (np && !of_property_read_string(np, "rx-mode", &rx_mode)) { 242 243 if (!strcmp(rx_mode, "uhf")) { 244 rc_dev->rxuhfmode = true; 245 } else if (!strcmp(rx_mode, "infrared")) { 246 rc_dev->rxuhfmode = false; 247 } else { 248 dev_err(dev, "Unsupported rx mode [%s]\n", rx_mode); 249 goto err; 250 } 251 252 } else { 253 goto err; 254 } 255 256 rc_dev->sys_clock = devm_clk_get(dev, NULL); 257 if (IS_ERR(rc_dev->sys_clock)) { 258 dev_err(dev, "System clock not found\n"); 259 ret = PTR_ERR(rc_dev->sys_clock); 260 goto err; 261 } 262 263 rc_dev->irq = platform_get_irq(pdev, 0); 264 if (rc_dev->irq < 0) { 265 ret = rc_dev->irq; 266 goto err; 267 } 268 269 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 270 271 rc_dev->base = devm_ioremap_resource(dev, res); 272 if (IS_ERR(rc_dev->base)) { 273 ret = PTR_ERR(rc_dev->base); 274 goto err; 275 } 276 277 if (rc_dev->rxuhfmode) 278 rc_dev->rx_base = rc_dev->base + 0x40; 279 else 280 rc_dev->rx_base = rc_dev->base; 281 282 rc_dev->rstc = reset_control_get_optional_exclusive(dev, NULL); 283 if (IS_ERR(rc_dev->rstc)) { 284 ret = PTR_ERR(rc_dev->rstc); 285 goto err; 286 } 287 288 rc_dev->dev = dev; 289 platform_set_drvdata(pdev, rc_dev); 290 st_rc_hardware_init(rc_dev); 291 292 rdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER; 293 /* rx sampling rate is 10Mhz */ 294 rdev->rx_resolution = 100; 295 rdev->timeout = US_TO_NS(MAX_SYMB_TIME); 296 rdev->priv = rc_dev; 297 rdev->open = st_rc_open; 298 rdev->close = st_rc_close; 299 rdev->driver_name = IR_ST_NAME; 300 rdev->map_name = RC_MAP_EMPTY; 301 rdev->device_name = "ST Remote Control Receiver"; 302 303 ret = rc_register_device(rdev); 304 if (ret < 0) 305 goto clkerr; 306 307 rc_dev->rdev = rdev; 308 if (devm_request_irq(dev, rc_dev->irq, st_rc_rx_interrupt, 309 0, IR_ST_NAME, rc_dev) < 0) { 310 dev_err(dev, "IRQ %d register failed\n", rc_dev->irq); 311 ret = -EINVAL; 312 goto rcerr; 313 } 314 315 /* enable wake via this device */ 316 device_init_wakeup(dev, true); 317 dev_pm_set_wake_irq(dev, rc_dev->irq); 318 319 /* 320 * for LIRC_MODE_MODE2 or LIRC_MODE_PULSE or LIRC_MODE_RAW 321 * lircd expects a long space first before a signal train to sync. 322 */ 323 st_rc_send_lirc_timeout(rdev); 324 325 dev_info(dev, "setup in %s mode\n", rc_dev->rxuhfmode ? "UHF" : "IR"); 326 327 return ret; 328 rcerr: 329 rc_unregister_device(rdev); 330 rdev = NULL; 331 clkerr: 332 clk_disable_unprepare(rc_dev->sys_clock); 333 err: 334 rc_free_device(rdev); 335 dev_err(dev, "Unable to register device (%d)\n", ret); 336 return ret; 337 } 338 339 #ifdef CONFIG_PM_SLEEP 340 static int st_rc_suspend(struct device *dev) 341 { 342 struct st_rc_device *rc_dev = dev_get_drvdata(dev); 343 344 if (device_may_wakeup(dev)) { 345 if (!enable_irq_wake(rc_dev->irq)) 346 rc_dev->irq_wake = 1; 347 else 348 return -EINVAL; 349 } else { 350 pinctrl_pm_select_sleep_state(dev); 351 writel(0x00, rc_dev->rx_base + IRB_RX_EN); 352 writel(0x00, rc_dev->rx_base + IRB_RX_INT_EN); 353 clk_disable_unprepare(rc_dev->sys_clock); 354 reset_control_assert(rc_dev->rstc); 355 } 356 357 return 0; 358 } 359 360 static int st_rc_resume(struct device *dev) 361 { 362 struct st_rc_device *rc_dev = dev_get_drvdata(dev); 363 struct rc_dev *rdev = rc_dev->rdev; 364 365 if (rc_dev->irq_wake) { 366 disable_irq_wake(rc_dev->irq); 367 rc_dev->irq_wake = 0; 368 } else { 369 pinctrl_pm_select_default_state(dev); 370 st_rc_hardware_init(rc_dev); 371 if (rdev->users) { 372 writel(IRB_RX_INTS, rc_dev->rx_base + IRB_RX_INT_EN); 373 writel(0x01, rc_dev->rx_base + IRB_RX_EN); 374 } 375 } 376 377 return 0; 378 } 379 380 #endif 381 382 static SIMPLE_DEV_PM_OPS(st_rc_pm_ops, st_rc_suspend, st_rc_resume); 383 384 #ifdef CONFIG_OF 385 static const struct of_device_id st_rc_match[] = { 386 { .compatible = "st,comms-irb", }, 387 {}, 388 }; 389 390 MODULE_DEVICE_TABLE(of, st_rc_match); 391 #endif 392 393 static struct platform_driver st_rc_driver = { 394 .driver = { 395 .name = IR_ST_NAME, 396 .of_match_table = of_match_ptr(st_rc_match), 397 .pm = &st_rc_pm_ops, 398 }, 399 .probe = st_rc_probe, 400 .remove = st_rc_remove, 401 }; 402 403 module_platform_driver(st_rc_driver); 404 405 MODULE_DESCRIPTION("RC Transceiver driver for STMicroelectronics platforms"); 406 MODULE_AUTHOR("STMicroelectronics (R&D) Ltd"); 407 MODULE_LICENSE("GPL"); 408