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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
6691e7b9 SW |
2 | /* |
3 | * Driver for Mediatek IR Receiver Controller | |
4 | * | |
5 | * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com> | |
6691e7b9 SW |
6 | */ |
7 | ||
8 | #include <linux/clk.h> | |
9 | #include <linux/interrupt.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/of_platform.h> | |
12 | #include <linux/reset.h> | |
13 | #include <media/rc-core.h> | |
14 | ||
15 | #define MTK_IR_DEV KBUILD_MODNAME | |
16 | ||
17 | /* Register to enable PWM and IR */ | |
18 | #define MTK_CONFIG_HIGH_REG 0x0c | |
50c3c1ba SW |
19 | |
20 | /* Bit to enable IR pulse width detection */ | |
6691e7b9 | 21 | #define MTK_PWM_EN BIT(13) |
6691e7b9 | 22 | |
50c3c1ba SW |
23 | /* |
24 | * Register to setting ok count whose unit based on hardware sampling period | |
25 | * indicating IR receiving completion and then making IRQ fires | |
26 | */ | |
27 | #define MTK_OK_COUNT(x) (((x) & GENMASK(23, 16)) << 16) | |
28 | ||
29 | /* Bit to enable IR hardware function */ | |
30 | #define MTK_IR_EN BIT(0) | |
6691e7b9 | 31 | |
6691e7b9 SW |
32 | /* Bit to restart IR receiving */ |
33 | #define MTK_IRCLR BIT(0) | |
34 | ||
50c3c1ba | 35 | /* Fields containing pulse width data */ |
6691e7b9 SW |
36 | #define MTK_WIDTH_MASK (GENMASK(7, 0)) |
37 | ||
6691e7b9 SW |
38 | /* Bit to enable interrupt */ |
39 | #define MTK_IRINT_EN BIT(0) | |
40 | ||
6691e7b9 SW |
41 | /* Bit to clear interrupt status */ |
42 | #define MTK_IRINT_CLR BIT(0) | |
43 | ||
44 | /* Maximum count of samples */ | |
45 | #define MTK_MAX_SAMPLES 0xff | |
46 | /* Indicate the end of IR message */ | |
47 | #define MTK_IR_END(v, p) ((v) == MTK_MAX_SAMPLES && (p) == 0) | |
48 | /* Number of registers to record the pulse width */ | |
49 | #define MTK_CHKDATA_SZ 17 | |
6691e7b9 | 50 | /* Sample period in ns */ |
50c3c1ba SW |
51 | #define MTK_IR_SAMPLE 46000 |
52 | ||
53 | enum mtk_fields { | |
54 | /* Register to setting software sampling period */ | |
55 | MTK_CHK_PERIOD, | |
56 | /* Register to setting hardware sampling period */ | |
57 | MTK_HW_PERIOD, | |
58 | }; | |
59 | ||
60 | enum mtk_regs { | |
61 | /* Register to clear state of state machine */ | |
62 | MTK_IRCLR_REG, | |
63 | /* Register containing pulse width data */ | |
64 | MTK_CHKDATA_REG, | |
65 | /* Register to enable IR interrupt */ | |
66 | MTK_IRINT_EN_REG, | |
67 | /* Register to ack IR interrupt */ | |
68 | MTK_IRINT_CLR_REG | |
69 | }; | |
70 | ||
71 | static const u32 mt7623_regs[] = { | |
72 | [MTK_IRCLR_REG] = 0x20, | |
73 | [MTK_CHKDATA_REG] = 0x88, | |
74 | [MTK_IRINT_EN_REG] = 0xcc, | |
75 | [MTK_IRINT_CLR_REG] = 0xd0, | |
76 | }; | |
77 | ||
58389982 SW |
78 | static const u32 mt7622_regs[] = { |
79 | [MTK_IRCLR_REG] = 0x18, | |
80 | [MTK_CHKDATA_REG] = 0x30, | |
81 | [MTK_IRINT_EN_REG] = 0x1c, | |
82 | [MTK_IRINT_CLR_REG] = 0x20, | |
83 | }; | |
84 | ||
50c3c1ba SW |
85 | struct mtk_field_type { |
86 | u32 reg; | |
87 | u8 offset; | |
88 | u32 mask; | |
89 | }; | |
90 | ||
91 | /* | |
92 | * struct mtk_ir_data - This is the structure holding all differences among | |
93 | various hardwares | |
94 | * @regs: The pointer to the array holding registers offset | |
95 | * @fields: The pointer to the array holding fields location | |
96 | * @div: The internal divisor for the based reference clock | |
97 | * @ok_count: The count indicating the completion of IR data | |
98 | * receiving when count is reached | |
99 | * @hw_period: The value indicating the hardware sampling period | |
100 | */ | |
101 | struct mtk_ir_data { | |
102 | const u32 *regs; | |
103 | const struct mtk_field_type *fields; | |
104 | u8 div; | |
105 | u8 ok_count; | |
106 | u32 hw_period; | |
107 | }; | |
108 | ||
109 | static const struct mtk_field_type mt7623_fields[] = { | |
110 | [MTK_CHK_PERIOD] = {0x10, 8, GENMASK(20, 8)}, | |
111 | [MTK_HW_PERIOD] = {0x10, 0, GENMASK(7, 0)}, | |
112 | }; | |
6691e7b9 | 113 | |
58389982 SW |
114 | static const struct mtk_field_type mt7622_fields[] = { |
115 | [MTK_CHK_PERIOD] = {0x24, 0, GENMASK(24, 0)}, | |
116 | [MTK_HW_PERIOD] = {0x10, 0, GENMASK(24, 0)}, | |
117 | }; | |
118 | ||
6691e7b9 SW |
119 | /* |
120 | * struct mtk_ir - This is the main datasructure for holding the state | |
121 | * of the driver | |
122 | * @dev: The device pointer | |
123 | * @rc: The rc instrance | |
6691e7b9 | 124 | * @base: The mapped register i/o base |
50c3c1ba SW |
125 | * @irq: The IRQ that we are using |
126 | * @clk: The clock that IR internal is using | |
127 | * @bus: The clock that software decoder is using | |
128 | * @data: Holding specific data for vaious platform | |
6691e7b9 SW |
129 | */ |
130 | struct mtk_ir { | |
131 | struct device *dev; | |
132 | struct rc_dev *rc; | |
133 | void __iomem *base; | |
134 | int irq; | |
135 | struct clk *clk; | |
50c3c1ba SW |
136 | struct clk *bus; |
137 | const struct mtk_ir_data *data; | |
6691e7b9 SW |
138 | }; |
139 | ||
50c3c1ba SW |
140 | static inline u32 mtk_chkdata_reg(struct mtk_ir *ir, u32 i) |
141 | { | |
142 | return ir->data->regs[MTK_CHKDATA_REG] + 4 * i; | |
143 | } | |
144 | ||
145 | static inline u32 mtk_chk_period(struct mtk_ir *ir) | |
146 | { | |
147 | u32 val; | |
148 | ||
149 | /* Period of raw software sampling in ns */ | |
150 | val = DIV_ROUND_CLOSEST(1000000000ul, | |
151 | clk_get_rate(ir->bus) / ir->data->div); | |
152 | ||
153 | /* | |
154 | * Period for software decoder used in the | |
155 | * unit of raw software sampling | |
156 | */ | |
157 | val = DIV_ROUND_CLOSEST(MTK_IR_SAMPLE, val); | |
158 | ||
159 | dev_dbg(ir->dev, "@pwm clk = \t%lu\n", | |
160 | clk_get_rate(ir->bus) / ir->data->div); | |
161 | dev_dbg(ir->dev, "@chkperiod = %08x\n", val); | |
162 | ||
163 | return val; | |
164 | } | |
165 | ||
6691e7b9 SW |
166 | static void mtk_w32_mask(struct mtk_ir *ir, u32 val, u32 mask, unsigned int reg) |
167 | { | |
168 | u32 tmp; | |
169 | ||
170 | tmp = __raw_readl(ir->base + reg); | |
171 | tmp = (tmp & ~mask) | val; | |
172 | __raw_writel(tmp, ir->base + reg); | |
173 | } | |
174 | ||
175 | static void mtk_w32(struct mtk_ir *ir, u32 val, unsigned int reg) | |
176 | { | |
177 | __raw_writel(val, ir->base + reg); | |
178 | } | |
179 | ||
180 | static u32 mtk_r32(struct mtk_ir *ir, unsigned int reg) | |
181 | { | |
182 | return __raw_readl(ir->base + reg); | |
183 | } | |
184 | ||
185 | static inline void mtk_irq_disable(struct mtk_ir *ir, u32 mask) | |
186 | { | |
187 | u32 val; | |
188 | ||
50c3c1ba SW |
189 | val = mtk_r32(ir, ir->data->regs[MTK_IRINT_EN_REG]); |
190 | mtk_w32(ir, val & ~mask, ir->data->regs[MTK_IRINT_EN_REG]); | |
6691e7b9 SW |
191 | } |
192 | ||
193 | static inline void mtk_irq_enable(struct mtk_ir *ir, u32 mask) | |
194 | { | |
195 | u32 val; | |
196 | ||
50c3c1ba SW |
197 | val = mtk_r32(ir, ir->data->regs[MTK_IRINT_EN_REG]); |
198 | mtk_w32(ir, val | mask, ir->data->regs[MTK_IRINT_EN_REG]); | |
6691e7b9 SW |
199 | } |
200 | ||
201 | static irqreturn_t mtk_ir_irq(int irqno, void *dev_id) | |
202 | { | |
203 | struct mtk_ir *ir = dev_id; | |
204 | u8 wid = 0; | |
205 | u32 i, j, val; | |
183e19f5 | 206 | struct ir_raw_event rawir = {}; |
6691e7b9 SW |
207 | |
208 | /* | |
209 | * Reset decoder state machine explicitly is required | |
210 | * because 1) the longest duration for space MTK IR hardware | |
211 | * could record is not safely long. e.g 12ms if rx resolution | |
212 | * is 46us by default. There is still the risk to satisfying | |
213 | * every decoder to reset themselves through long enough | |
214 | * trailing spaces and 2) the IRQ handler guarantees that | |
215 | * start of IR message is always contained in and starting | |
50c3c1ba | 216 | * from register mtk_chkdata_reg(ir, i). |
6691e7b9 SW |
217 | */ |
218 | ir_raw_event_reset(ir->rc); | |
219 | ||
220 | /* First message must be pulse */ | |
221 | rawir.pulse = false; | |
222 | ||
223 | /* Handle all pulse and space IR controller captures */ | |
224 | for (i = 0 ; i < MTK_CHKDATA_SZ ; i++) { | |
50c3c1ba | 225 | val = mtk_r32(ir, mtk_chkdata_reg(ir, i)); |
6691e7b9 SW |
226 | dev_dbg(ir->dev, "@reg%d=0x%08x\n", i, val); |
227 | ||
228 | for (j = 0 ; j < 4 ; j++) { | |
229 | wid = (val & (MTK_WIDTH_MASK << j * 8)) >> j * 8; | |
230 | rawir.pulse = !rawir.pulse; | |
231 | rawir.duration = wid * (MTK_IR_SAMPLE + 1); | |
232 | ir_raw_event_store_with_filter(ir->rc, &rawir); | |
233 | } | |
234 | } | |
235 | ||
236 | /* | |
237 | * The maximum number of edges the IR controller can | |
238 | * hold is MTK_CHKDATA_SZ * 4. So if received IR messages | |
239 | * is over the limit, the last incomplete IR message would | |
240 | * be appended trailing space and still would be sent into | |
241 | * ir-rc-raw to decode. That helps it is possible that it | |
242 | * has enough information to decode a scancode even if the | |
243 | * trailing end of the message is missing. | |
244 | */ | |
245 | if (!MTK_IR_END(wid, rawir.pulse)) { | |
246 | rawir.pulse = false; | |
247 | rawir.duration = MTK_MAX_SAMPLES * (MTK_IR_SAMPLE + 1); | |
248 | ir_raw_event_store_with_filter(ir->rc, &rawir); | |
249 | } | |
250 | ||
251 | ir_raw_event_handle(ir->rc); | |
252 | ||
253 | /* | |
254 | * Restart controller for the next receive that would | |
255 | * clear up all CHKDATA registers | |
256 | */ | |
50c3c1ba | 257 | mtk_w32_mask(ir, 0x1, MTK_IRCLR, ir->data->regs[MTK_IRCLR_REG]); |
6691e7b9 SW |
258 | |
259 | /* Clear interrupt status */ | |
50c3c1ba SW |
260 | mtk_w32_mask(ir, 0x1, MTK_IRINT_CLR, |
261 | ir->data->regs[MTK_IRINT_CLR_REG]); | |
6691e7b9 SW |
262 | |
263 | return IRQ_HANDLED; | |
264 | } | |
265 | ||
50c3c1ba SW |
266 | static const struct mtk_ir_data mt7623_data = { |
267 | .regs = mt7623_regs, | |
268 | .fields = mt7623_fields, | |
269 | .ok_count = 0xf, | |
270 | .hw_period = 0xff, | |
271 | .div = 4, | |
272 | }; | |
273 | ||
58389982 SW |
274 | static const struct mtk_ir_data mt7622_data = { |
275 | .regs = mt7622_regs, | |
276 | .fields = mt7622_fields, | |
277 | .ok_count = 0xf, | |
278 | .hw_period = 0xffff, | |
279 | .div = 32, | |
280 | }; | |
281 | ||
50c3c1ba SW |
282 | static const struct of_device_id mtk_ir_match[] = { |
283 | { .compatible = "mediatek,mt7623-cir", .data = &mt7623_data}, | |
58389982 | 284 | { .compatible = "mediatek,mt7622-cir", .data = &mt7622_data}, |
50c3c1ba SW |
285 | {}, |
286 | }; | |
287 | MODULE_DEVICE_TABLE(of, mtk_ir_match); | |
288 | ||
6691e7b9 SW |
289 | static int mtk_ir_probe(struct platform_device *pdev) |
290 | { | |
291 | struct device *dev = &pdev->dev; | |
292 | struct device_node *dn = dev->of_node; | |
293 | struct resource *res; | |
294 | struct mtk_ir *ir; | |
295 | u32 val; | |
296 | int ret = 0; | |
297 | const char *map_name; | |
298 | ||
299 | ir = devm_kzalloc(dev, sizeof(struct mtk_ir), GFP_KERNEL); | |
300 | if (!ir) | |
301 | return -ENOMEM; | |
302 | ||
303 | ir->dev = dev; | |
5d0af51f | 304 | ir->data = of_device_get_match_data(dev); |
6691e7b9 SW |
305 | |
306 | ir->clk = devm_clk_get(dev, "clk"); | |
307 | if (IS_ERR(ir->clk)) { | |
308 | dev_err(dev, "failed to get a ir clock.\n"); | |
309 | return PTR_ERR(ir->clk); | |
310 | } | |
311 | ||
50c3c1ba SW |
312 | ir->bus = devm_clk_get(dev, "bus"); |
313 | if (IS_ERR(ir->bus)) { | |
314 | /* | |
315 | * For compatibility with older device trees try unnamed | |
316 | * ir->bus uses the same clock as ir->clock. | |
317 | */ | |
318 | ir->bus = ir->clk; | |
319 | } | |
320 | ||
6691e7b9 SW |
321 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
322 | ir->base = devm_ioremap_resource(dev, res); | |
323 | if (IS_ERR(ir->base)) { | |
324 | dev_err(dev, "failed to map registers\n"); | |
325 | return PTR_ERR(ir->base); | |
326 | } | |
327 | ||
328 | ir->rc = devm_rc_allocate_device(dev, RC_DRIVER_IR_RAW); | |
329 | if (!ir->rc) { | |
330 | dev_err(dev, "failed to allocate device\n"); | |
331 | return -ENOMEM; | |
332 | } | |
333 | ||
334 | ir->rc->priv = ir; | |
518f4b26 | 335 | ir->rc->device_name = MTK_IR_DEV; |
6691e7b9 SW |
336 | ir->rc->input_phys = MTK_IR_DEV "/input0"; |
337 | ir->rc->input_id.bustype = BUS_HOST; | |
338 | ir->rc->input_id.vendor = 0x0001; | |
339 | ir->rc->input_id.product = 0x0001; | |
340 | ir->rc->input_id.version = 0x0001; | |
341 | map_name = of_get_property(dn, "linux,rc-map-name", NULL); | |
342 | ir->rc->map_name = map_name ?: RC_MAP_EMPTY; | |
343 | ir->rc->dev.parent = dev; | |
344 | ir->rc->driver_name = MTK_IR_DEV; | |
6d741bfe | 345 | ir->rc->allowed_protocols = RC_PROTO_BIT_ALL; |
6691e7b9 SW |
346 | ir->rc->rx_resolution = MTK_IR_SAMPLE; |
347 | ir->rc->timeout = MTK_MAX_SAMPLES * (MTK_IR_SAMPLE + 1); | |
348 | ||
349 | ret = devm_rc_register_device(dev, ir->rc); | |
350 | if (ret) { | |
351 | dev_err(dev, "failed to register rc device\n"); | |
352 | return ret; | |
353 | } | |
354 | ||
355 | platform_set_drvdata(pdev, ir); | |
356 | ||
357 | ir->irq = platform_get_irq(pdev, 0); | |
358 | if (ir->irq < 0) { | |
359 | dev_err(dev, "no irq resource\n"); | |
360 | return -ENODEV; | |
361 | } | |
362 | ||
6691e7b9 | 363 | if (clk_prepare_enable(ir->clk)) { |
50c3c1ba SW |
364 | dev_err(dev, "try to enable ir_clk failed\n"); |
365 | return -EINVAL; | |
366 | } | |
367 | ||
368 | if (clk_prepare_enable(ir->bus)) { | |
6691e7b9 SW |
369 | dev_err(dev, "try to enable ir_clk failed\n"); |
370 | ret = -EINVAL; | |
371 | goto exit_clkdisable_clk; | |
372 | } | |
373 | ||
50c3c1ba SW |
374 | /* |
375 | * Enable interrupt after proper hardware | |
376 | * setup and IRQ handler registration | |
377 | */ | |
6691e7b9 SW |
378 | mtk_irq_disable(ir, MTK_IRINT_EN); |
379 | ||
380 | ret = devm_request_irq(dev, ir->irq, mtk_ir_irq, 0, MTK_IR_DEV, ir); | |
381 | if (ret) { | |
382 | dev_err(dev, "failed request irq\n"); | |
50c3c1ba | 383 | goto exit_clkdisable_bus; |
6691e7b9 SW |
384 | } |
385 | ||
50c3c1ba SW |
386 | /* |
387 | * Setup software sample period as the reference of software decoder | |
388 | */ | |
389 | val = (mtk_chk_period(ir) << ir->data->fields[MTK_CHK_PERIOD].offset) & | |
390 | ir->data->fields[MTK_CHK_PERIOD].mask; | |
391 | mtk_w32_mask(ir, val, ir->data->fields[MTK_CHK_PERIOD].mask, | |
392 | ir->data->fields[MTK_CHK_PERIOD].reg); | |
393 | ||
394 | /* | |
395 | * Setup hardware sampling period used to setup the proper timeout for | |
396 | * indicating end of IR receiving completion | |
397 | */ | |
398 | val = (ir->data->hw_period << ir->data->fields[MTK_HW_PERIOD].offset) & | |
399 | ir->data->fields[MTK_HW_PERIOD].mask; | |
400 | mtk_w32_mask(ir, val, ir->data->fields[MTK_HW_PERIOD].mask, | |
401 | ir->data->fields[MTK_HW_PERIOD].reg); | |
402 | ||
6691e7b9 SW |
403 | /* Enable IR and PWM */ |
404 | val = mtk_r32(ir, MTK_CONFIG_HIGH_REG); | |
50c3c1ba | 405 | val |= MTK_OK_COUNT(ir->data->ok_count) | MTK_PWM_EN | MTK_IR_EN; |
6691e7b9 SW |
406 | mtk_w32(ir, val, MTK_CONFIG_HIGH_REG); |
407 | ||
6691e7b9 SW |
408 | mtk_irq_enable(ir, MTK_IRINT_EN); |
409 | ||
50c3c1ba | 410 | dev_info(dev, "Initialized MT7623 IR driver, sample period = %dus\n", |
6691e7b9 SW |
411 | DIV_ROUND_CLOSEST(MTK_IR_SAMPLE, 1000)); |
412 | ||
413 | return 0; | |
414 | ||
50c3c1ba SW |
415 | exit_clkdisable_bus: |
416 | clk_disable_unprepare(ir->bus); | |
6691e7b9 SW |
417 | exit_clkdisable_clk: |
418 | clk_disable_unprepare(ir->clk); | |
419 | ||
420 | return ret; | |
421 | } | |
422 | ||
423 | static int mtk_ir_remove(struct platform_device *pdev) | |
424 | { | |
425 | struct mtk_ir *ir = platform_get_drvdata(pdev); | |
426 | ||
427 | /* | |
428 | * Avoid contention between remove handler and | |
429 | * IRQ handler so that disabling IR interrupt and | |
430 | * waiting for pending IRQ handler to complete | |
431 | */ | |
432 | mtk_irq_disable(ir, MTK_IRINT_EN); | |
433 | synchronize_irq(ir->irq); | |
434 | ||
50c3c1ba | 435 | clk_disable_unprepare(ir->bus); |
6691e7b9 SW |
436 | clk_disable_unprepare(ir->clk); |
437 | ||
438 | return 0; | |
439 | } | |
440 | ||
6691e7b9 SW |
441 | static struct platform_driver mtk_ir_driver = { |
442 | .probe = mtk_ir_probe, | |
443 | .remove = mtk_ir_remove, | |
444 | .driver = { | |
445 | .name = MTK_IR_DEV, | |
446 | .of_match_table = mtk_ir_match, | |
447 | }, | |
448 | }; | |
449 | ||
450 | module_platform_driver(mtk_ir_driver); | |
451 | ||
452 | MODULE_DESCRIPTION("Mediatek IR Receiver Controller Driver"); | |
453 | MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>"); | |
454 | MODULE_LICENSE("GPL"); |