1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * meson-ir-tx.c - Amlogic Meson IR TX driver 4 * 5 * Copyright (c) 2021, SberDevices. All Rights Reserved. 6 * 7 * Author: Viktor Prutyanov <viktor.prutyanov@phystech.edu> 8 */ 9 10 #include <linux/device.h> 11 #include <linux/module.h> 12 #include <linux/sched.h> 13 #include <linux/platform_device.h> 14 #include <linux/of.h> 15 #include <linux/interrupt.h> 16 #include <linux/spinlock.h> 17 #include <linux/of_irq.h> 18 #include <linux/clk.h> 19 #include <linux/slab.h> 20 #include <media/rc-core.h> 21 22 #define DEVICE_NAME "Meson IR TX" 23 #define DRIVER_NAME "meson-ir-tx" 24 25 #define MIRTX_DEFAULT_CARRIER 38000 26 #define MIRTX_DEFAULT_DUTY_CYCLE 50 27 #define MIRTX_FIFO_THD 32 28 29 #define IRB_MOD_1US_CLK_RATE 1000000 30 31 #define IRB_FIFO_LEN 128 32 33 #define IRB_ADDR0 0x0 34 #define IRB_ADDR1 0x4 35 #define IRB_ADDR2 0x8 36 #define IRB_ADDR3 0xc 37 38 #define IRB_MAX_DELAY (1 << 10) 39 #define IRB_DELAY_MASK (IRB_MAX_DELAY - 1) 40 41 /* IRCTRL_IR_BLASTER_ADDR0 */ 42 #define IRB_MOD_CLK(x) ((x) << 12) 43 #define IRB_MOD_SYS_CLK 0 44 #define IRB_MOD_XTAL3_CLK 1 45 #define IRB_MOD_1US_CLK 2 46 #define IRB_MOD_10US_CLK 3 47 #define IRB_INIT_HIGH BIT(2) 48 #define IRB_ENABLE BIT(0) 49 50 /* IRCTRL_IR_BLASTER_ADDR2 */ 51 #define IRB_MOD_COUNT(lo, hi) ((((lo) - 1) << 16) | ((hi) - 1)) 52 53 /* IRCTRL_IR_BLASTER_ADDR2 */ 54 #define IRB_WRITE_FIFO BIT(16) 55 #define IRB_MOD_ENABLE BIT(12) 56 #define IRB_TB_1US (0x0 << 10) 57 #define IRB_TB_10US (0x1 << 10) 58 #define IRB_TB_100US (0x2 << 10) 59 #define IRB_TB_MOD_CLK (0x3 << 10) 60 61 /* IRCTRL_IR_BLASTER_ADDR3 */ 62 #define IRB_FIFO_THD_PENDING BIT(16) 63 #define IRB_FIFO_IRQ_ENABLE BIT(8) 64 65 struct meson_irtx { 66 struct device *dev; 67 void __iomem *reg_base; 68 u32 *buf; 69 unsigned int buf_len; 70 unsigned int buf_head; 71 unsigned int carrier; 72 unsigned int duty_cycle; 73 /* Locks buf */ 74 spinlock_t lock; 75 struct completion completion; 76 unsigned long clk_rate; 77 }; 78 79 static void meson_irtx_set_mod(struct meson_irtx *ir) 80 { 81 unsigned int cnt = DIV_ROUND_CLOSEST(ir->clk_rate, ir->carrier); 82 unsigned int pulse_cnt = DIV_ROUND_CLOSEST(cnt * ir->duty_cycle, 100); 83 unsigned int space_cnt = cnt - pulse_cnt; 84 85 dev_dbg(ir->dev, "F_mod = %uHz, T_mod = %luns, duty_cycle = %u%%\n", 86 ir->carrier, NSEC_PER_SEC / ir->clk_rate * cnt, 87 100 * pulse_cnt / cnt); 88 89 writel(IRB_MOD_COUNT(pulse_cnt, space_cnt), 90 ir->reg_base + IRB_ADDR1); 91 } 92 93 static void meson_irtx_setup(struct meson_irtx *ir, unsigned int clk_nr) 94 { 95 /* 96 * Disable the TX, set modulator clock tick and set initialize 97 * output to be high. Set up carrier frequency and duty cycle. Then 98 * unset initialize output. Enable FIFO interrupt, set FIFO interrupt 99 * threshold. Finally, enable the transmitter back. 100 */ 101 writel(~IRB_ENABLE & (IRB_MOD_CLK(clk_nr) | IRB_INIT_HIGH), 102 ir->reg_base + IRB_ADDR0); 103 meson_irtx_set_mod(ir); 104 writel(readl(ir->reg_base + IRB_ADDR0) & ~IRB_INIT_HIGH, 105 ir->reg_base + IRB_ADDR0); 106 writel(IRB_FIFO_IRQ_ENABLE | MIRTX_FIFO_THD, 107 ir->reg_base + IRB_ADDR3); 108 writel(readl(ir->reg_base + IRB_ADDR0) | IRB_ENABLE, 109 ir->reg_base + IRB_ADDR0); 110 } 111 112 static u32 meson_irtx_prepare_pulse(struct meson_irtx *ir, unsigned int time) 113 { 114 unsigned int delay; 115 unsigned int tb = IRB_TB_MOD_CLK; 116 unsigned int tb_us = DIV_ROUND_CLOSEST(USEC_PER_SEC, ir->carrier); 117 118 delay = (DIV_ROUND_CLOSEST(time, tb_us) - 1) & IRB_DELAY_MASK; 119 120 return ((IRB_WRITE_FIFO | IRB_MOD_ENABLE) | tb | delay); 121 } 122 123 static u32 meson_irtx_prepare_space(struct meson_irtx *ir, unsigned int time) 124 { 125 unsigned int delay; 126 unsigned int tb = IRB_TB_100US; 127 unsigned int tb_us = 100; 128 129 if (time <= IRB_MAX_DELAY) { 130 tb = IRB_TB_1US; 131 tb_us = 1; 132 } else if (time <= 10 * IRB_MAX_DELAY) { 133 tb = IRB_TB_10US; 134 tb_us = 10; 135 } else if (time <= 100 * IRB_MAX_DELAY) { 136 tb = IRB_TB_100US; 137 tb_us = 100; 138 } 139 140 delay = (DIV_ROUND_CLOSEST(time, tb_us) - 1) & IRB_DELAY_MASK; 141 142 return ((IRB_WRITE_FIFO & ~IRB_MOD_ENABLE) | tb | delay); 143 } 144 145 static void meson_irtx_send_buffer(struct meson_irtx *ir) 146 { 147 unsigned int nr = 0; 148 unsigned int max_fifo_level = IRB_FIFO_LEN - MIRTX_FIFO_THD; 149 150 while (ir->buf_head < ir->buf_len && nr < max_fifo_level) { 151 writel(ir->buf[ir->buf_head], ir->reg_base + IRB_ADDR2); 152 153 ir->buf_head++; 154 nr++; 155 } 156 } 157 158 static bool meson_irtx_check_buf(struct meson_irtx *ir, 159 unsigned int *buf, unsigned int len) 160 { 161 unsigned int i; 162 163 for (i = 0; i < len; i++) { 164 unsigned int max_tb_us; 165 /* 166 * Max space timebase is 100 us. 167 * Pulse timebase equals to carrier period. 168 */ 169 if (i % 2 == 0) 170 max_tb_us = USEC_PER_SEC / ir->carrier; 171 else 172 max_tb_us = 100; 173 174 if (buf[i] >= max_tb_us * IRB_MAX_DELAY) 175 return false; 176 } 177 178 return true; 179 } 180 181 static void meson_irtx_fill_buf(struct meson_irtx *ir, u32 *dst_buf, 182 unsigned int *src_buf, unsigned int len) 183 { 184 unsigned int i; 185 186 for (i = 0; i < len; i++) { 187 if (i % 2 == 0) 188 dst_buf[i] = meson_irtx_prepare_pulse(ir, src_buf[i]); 189 else 190 dst_buf[i] = meson_irtx_prepare_space(ir, src_buf[i]); 191 } 192 } 193 194 static irqreturn_t meson_irtx_irqhandler(int irq, void *data) 195 { 196 unsigned long flags; 197 struct meson_irtx *ir = data; 198 199 writel(readl(ir->reg_base + IRB_ADDR3) & ~IRB_FIFO_THD_PENDING, 200 ir->reg_base + IRB_ADDR3); 201 202 if (completion_done(&ir->completion)) 203 return IRQ_HANDLED; 204 205 spin_lock_irqsave(&ir->lock, flags); 206 if (ir->buf_head < ir->buf_len) 207 meson_irtx_send_buffer(ir); 208 else 209 complete(&ir->completion); 210 spin_unlock_irqrestore(&ir->lock, flags); 211 212 return IRQ_HANDLED; 213 } 214 215 static int meson_irtx_set_carrier(struct rc_dev *rc, u32 carrier) 216 { 217 struct meson_irtx *ir = rc->priv; 218 219 if (carrier == 0) 220 return -EINVAL; 221 222 ir->carrier = carrier; 223 meson_irtx_set_mod(ir); 224 225 return 0; 226 } 227 228 static int meson_irtx_set_duty_cycle(struct rc_dev *rc, u32 duty_cycle) 229 { 230 struct meson_irtx *ir = rc->priv; 231 232 ir->duty_cycle = duty_cycle; 233 meson_irtx_set_mod(ir); 234 235 return 0; 236 } 237 238 static void meson_irtx_update_buf(struct meson_irtx *ir, u32 *buf, 239 unsigned int len, unsigned int head) 240 { 241 ir->buf = buf; 242 ir->buf_len = len; 243 ir->buf_head = head; 244 } 245 246 static int meson_irtx_transmit(struct rc_dev *rc, unsigned int *buf, 247 unsigned int len) 248 { 249 unsigned long flags; 250 struct meson_irtx *ir = rc->priv; 251 u32 *tx_buf; 252 int ret = len; 253 254 if (!meson_irtx_check_buf(ir, buf, len)) 255 return -EINVAL; 256 257 tx_buf = kmalloc_array(len, sizeof(u32), GFP_KERNEL); 258 if (!tx_buf) 259 return -ENOMEM; 260 261 meson_irtx_fill_buf(ir, tx_buf, buf, len); 262 dev_dbg(ir->dev, "TX buffer filled, length = %u\n", len); 263 264 spin_lock_irqsave(&ir->lock, flags); 265 meson_irtx_update_buf(ir, tx_buf, len, 0); 266 reinit_completion(&ir->completion); 267 meson_irtx_send_buffer(ir); 268 spin_unlock_irqrestore(&ir->lock, flags); 269 270 if (!wait_for_completion_timeout(&ir->completion, 271 usecs_to_jiffies(IR_MAX_DURATION))) 272 ret = -ETIMEDOUT; 273 274 spin_lock_irqsave(&ir->lock, flags); 275 kfree(ir->buf); 276 meson_irtx_update_buf(ir, NULL, 0, 0); 277 spin_unlock_irqrestore(&ir->lock, flags); 278 279 return ret; 280 } 281 282 static int meson_irtx_mod_clock_probe(struct meson_irtx *ir, 283 unsigned int *clk_nr) 284 { 285 struct device_node *np = ir->dev->of_node; 286 struct clk *clock; 287 288 if (!np) 289 return -ENODEV; 290 291 clock = devm_clk_get(ir->dev, "xtal"); 292 if (IS_ERR(clock) || clk_prepare_enable(clock)) 293 return -ENODEV; 294 295 *clk_nr = IRB_MOD_XTAL3_CLK; 296 ir->clk_rate = clk_get_rate(clock) / 3; 297 298 if (ir->clk_rate < IRB_MOD_1US_CLK_RATE) { 299 *clk_nr = IRB_MOD_1US_CLK; 300 ir->clk_rate = IRB_MOD_1US_CLK_RATE; 301 } 302 303 dev_info(ir->dev, "F_clk = %luHz\n", ir->clk_rate); 304 305 return 0; 306 } 307 308 static int __init meson_irtx_probe(struct platform_device *pdev) 309 { 310 struct device *dev = &pdev->dev; 311 struct meson_irtx *ir; 312 struct rc_dev *rc; 313 int irq; 314 unsigned int clk_nr; 315 int ret; 316 317 ir = devm_kzalloc(dev, sizeof(*ir), GFP_KERNEL); 318 if (!ir) 319 return -ENOMEM; 320 321 ir->reg_base = devm_platform_ioremap_resource(pdev, 0); 322 if (IS_ERR(ir->reg_base)) 323 return PTR_ERR(ir->reg_base); 324 325 irq = platform_get_irq(pdev, 0); 326 if (irq < 0) { 327 dev_err(dev, "no irq resource found\n"); 328 return -ENODEV; 329 } 330 331 ir->dev = dev; 332 ir->carrier = MIRTX_DEFAULT_CARRIER; 333 ir->duty_cycle = MIRTX_DEFAULT_DUTY_CYCLE; 334 init_completion(&ir->completion); 335 spin_lock_init(&ir->lock); 336 337 ret = meson_irtx_mod_clock_probe(ir, &clk_nr); 338 if (ret) { 339 dev_err(dev, "modulator clock setup failed\n"); 340 return ret; 341 } 342 meson_irtx_setup(ir, clk_nr); 343 344 ret = devm_request_irq(dev, irq, 345 meson_irtx_irqhandler, 346 IRQF_TRIGGER_RISING, 347 DRIVER_NAME, ir); 348 if (ret) { 349 dev_err(dev, "irq request failed\n"); 350 return ret; 351 } 352 353 rc = rc_allocate_device(RC_DRIVER_IR_RAW_TX); 354 if (!rc) 355 return -ENOMEM; 356 357 rc->driver_name = DRIVER_NAME; 358 rc->device_name = DEVICE_NAME; 359 rc->priv = ir; 360 361 rc->tx_ir = meson_irtx_transmit; 362 rc->s_tx_carrier = meson_irtx_set_carrier; 363 rc->s_tx_duty_cycle = meson_irtx_set_duty_cycle; 364 365 ret = rc_register_device(rc); 366 if (ret < 0) { 367 dev_err(dev, "rc_dev registration failed\n"); 368 rc_free_device(rc); 369 return ret; 370 } 371 372 platform_set_drvdata(pdev, rc); 373 374 return 0; 375 } 376 377 static int meson_irtx_remove(struct platform_device *pdev) 378 { 379 struct rc_dev *rc = platform_get_drvdata(pdev); 380 381 rc_unregister_device(rc); 382 383 return 0; 384 } 385 386 static const struct of_device_id meson_irtx_dt_match[] = { 387 { 388 .compatible = "amlogic,meson-g12a-ir-tx", 389 }, 390 {}, 391 }; 392 MODULE_DEVICE_TABLE(of, meson_irtx_dt_match); 393 394 static struct platform_driver meson_irtx_pd = { 395 .remove = meson_irtx_remove, 396 .driver = { 397 .name = DRIVER_NAME, 398 .of_match_table = meson_irtx_dt_match, 399 }, 400 }; 401 402 module_platform_driver_probe(meson_irtx_pd, meson_irtx_probe); 403 404 MODULE_DESCRIPTION("Meson IR TX driver"); 405 MODULE_AUTHOR("Viktor Prutyanov <viktor.prutyanov@phystech.edu>"); 406 MODULE_LICENSE("GPL"); 407