2 * Copyright (C) 2013 STMicroelectronics Limited
3 * Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 #include <linux/kernel.h>
11 #include <linux/clk.h>
12 #include <linux/interrupt.h>
13 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/reset.h>
17 #include <media/rc-core.h>
18 #include <linux/pinctrl/consumer.h>
24 struct clk
*sys_clock
;
25 void *base
; /* Register base address */
26 void *rx_base
;/* RX Register base address */
32 struct reset_control
*rstc
;
36 #define IRB_SAMPLE_RATE_COMM 0x64 /* sample freq divisor*/
37 #define IRB_CLOCK_SEL 0x70 /* clock select */
38 #define IRB_CLOCK_SEL_STATUS 0x74 /* clock status */
39 /* IRB IR/UHF receiver registers */
40 #define IRB_RX_ON 0x40 /* pulse time capture */
41 #define IRB_RX_SYS 0X44 /* sym period capture */
42 #define IRB_RX_INT_EN 0x48 /* IRQ enable (R/W) */
43 #define IRB_RX_INT_STATUS 0x4c /* IRQ status (R/W) */
44 #define IRB_RX_EN 0x50 /* Receive enable */
45 #define IRB_MAX_SYM_PERIOD 0x54 /* max sym value */
46 #define IRB_RX_INT_CLEAR 0x58 /* overrun status */
47 #define IRB_RX_STATUS 0x6c /* receive status */
48 #define IRB_RX_NOISE_SUPPR 0x5c /* noise suppression */
49 #define IRB_RX_POLARITY_INV 0x68 /* polarity inverter */
52 * IRQ set: Enable full FIFO 1 -> bit 3;
53 * Enable overrun IRQ 1 -> bit 2;
54 * Enable last symbol IRQ 1 -> bit 1:
55 * Enable RX interrupt 1 -> bit 0;
57 #define IRB_RX_INTS 0x0f
58 #define IRB_RX_OVERRUN_INT 0x04
59 /* maximum symbol period (microsecs),timeout to detect end of symbol train */
60 #define MAX_SYMB_TIME 0x5000
61 #define IRB_SAMPLE_FREQ 10000000
62 #define IRB_FIFO_NOT_EMPTY 0xff00
63 #define IRB_OVERFLOW 0x4
64 #define IRB_TIMEOUT 0xffff
65 #define IR_ST_NAME "st-rc"
67 static void st_rc_send_lirc_timeout(struct rc_dev
*rdev
)
69 DEFINE_IR_RAW_EVENT(ev
);
71 ir_raw_event_store(rdev
, &ev
);
75 * RX graphical example to better understand the difference between ST IR block
76 * output and standard definition used by LIRC (and most of the world!)
79 * |-IRB_RX_ON-| |-IRB_RX_ON-|
80 * ___ ___ ___ ___ ___ ___ _
81 * | | | | | | | | | | | | |
82 * | | | | | | space 0 | | | | | | space 1 |
83 * _____| |__| |__| |____________________________| |__| |__| |_____________|
85 * |--------------- IRB_RX_SYS -------------|------ IRB_RX_SYS -------|
87 * |------------- encoding bit 0 -----------|---- encoding bit 1 -----|
89 * ST hardware returns mark (IRB_RX_ON) and total symbol time (IRB_RX_SYS), so
90 * convert to standard mark/space we have to calculate space=(IRB_RX_SYS-mark)
91 * The mark time represents the amount of time the carrier (usually 36-40kHz)
92 * is detected.The above examples shows Pulse Width Modulation encoding where
93 * bit 0 is represented by space>mark.
96 static irqreturn_t
st_rc_rx_interrupt(int irq
, void *data
)
98 unsigned int symbol
, mark
= 0;
99 struct st_rc_device
*dev
= data
;
102 DEFINE_IR_RAW_EVENT(ev
);
105 pm_wakeup_event(dev
->dev
, 0);
107 status
= readl(dev
->rx_base
+ IRB_RX_STATUS
);
109 while (status
& (IRB_FIFO_NOT_EMPTY
| IRB_OVERFLOW
)) {
110 u32 int_status
= readl(dev
->rx_base
+ IRB_RX_INT_STATUS
);
111 if (unlikely(int_status
& IRB_RX_OVERRUN_INT
)) {
112 /* discard the entire collection in case of errors! */
113 ir_raw_event_reset(dev
->rdev
);
114 dev_info(dev
->dev
, "IR RX overrun\n");
115 writel(IRB_RX_OVERRUN_INT
,
116 dev
->rx_base
+ IRB_RX_INT_CLEAR
);
120 symbol
= readl(dev
->rx_base
+ IRB_RX_SYS
);
121 mark
= readl(dev
->rx_base
+ IRB_RX_ON
);
123 if (symbol
== IRB_TIMEOUT
)
126 /* Ignore any noise */
127 if ((mark
> 2) && (symbol
> 1)) {
129 if (dev
->overclocking
) { /* adjustments to timings */
130 symbol
*= dev
->sample_mult
;
131 symbol
/= dev
->sample_div
;
132 mark
*= dev
->sample_mult
;
133 mark
/= dev
->sample_div
;
136 ev
.duration
= US_TO_NS(mark
);
138 ir_raw_event_store(dev
->rdev
, &ev
);
141 ev
.duration
= US_TO_NS(symbol
);
143 ir_raw_event_store(dev
->rdev
, &ev
);
145 st_rc_send_lirc_timeout(dev
->rdev
);
150 status
= readl(dev
->rx_base
+ IRB_RX_STATUS
);
153 writel(IRB_RX_INTS
, dev
->rx_base
+ IRB_RX_INT_CLEAR
);
155 /* Empty software fifo */
156 ir_raw_event_handle(dev
->rdev
);
160 static void st_rc_hardware_init(struct st_rc_device
*dev
)
162 int baseclock
, freqdiff
;
163 unsigned int rx_max_symbol_per
= MAX_SYMB_TIME
;
164 unsigned int rx_sampling_freq_div
;
168 reset_control_deassert(dev
->rstc
);
170 clk_prepare_enable(dev
->sys_clock
);
171 baseclock
= clk_get_rate(dev
->sys_clock
);
173 /* IRB input pins are inverted internally from high to low. */
174 writel(1, dev
->rx_base
+ IRB_RX_POLARITY_INV
);
176 rx_sampling_freq_div
= baseclock
/ IRB_SAMPLE_FREQ
;
177 writel(rx_sampling_freq_div
, dev
->base
+ IRB_SAMPLE_RATE_COMM
);
179 freqdiff
= baseclock
- (rx_sampling_freq_div
* IRB_SAMPLE_FREQ
);
180 if (freqdiff
) { /* over clocking, workout the adjustment factors */
181 dev
->overclocking
= true;
182 dev
->sample_mult
= 1000;
183 dev
->sample_div
= baseclock
/ (10000 * rx_sampling_freq_div
);
184 rx_max_symbol_per
= (rx_max_symbol_per
* 1000)/dev
->sample_div
;
187 writel(rx_max_symbol_per
, dev
->rx_base
+ IRB_MAX_SYM_PERIOD
);
190 static int st_rc_remove(struct platform_device
*pdev
)
192 struct st_rc_device
*rc_dev
= platform_get_drvdata(pdev
);
193 clk_disable_unprepare(rc_dev
->sys_clock
);
194 rc_unregister_device(rc_dev
->rdev
);
198 static int st_rc_open(struct rc_dev
*rdev
)
200 struct st_rc_device
*dev
= rdev
->priv
;
202 local_irq_save(flags
);
203 /* enable interrupts and receiver */
204 writel(IRB_RX_INTS
, dev
->rx_base
+ IRB_RX_INT_EN
);
205 writel(0x01, dev
->rx_base
+ IRB_RX_EN
);
206 local_irq_restore(flags
);
211 static void st_rc_close(struct rc_dev
*rdev
)
213 struct st_rc_device
*dev
= rdev
->priv
;
214 /* disable interrupts and receiver */
215 writel(0x00, dev
->rx_base
+ IRB_RX_EN
);
216 writel(0x00, dev
->rx_base
+ IRB_RX_INT_EN
);
219 static int st_rc_probe(struct platform_device
*pdev
)
223 struct device
*dev
= &pdev
->dev
;
224 struct resource
*res
;
225 struct st_rc_device
*rc_dev
;
226 struct device_node
*np
= pdev
->dev
.of_node
;
229 rc_dev
= devm_kzalloc(dev
, sizeof(struct st_rc_device
), GFP_KERNEL
);
234 rdev
= rc_allocate_device();
239 if (np
&& !of_property_read_string(np
, "rx-mode", &rx_mode
)) {
241 if (!strcmp(rx_mode
, "uhf")) {
242 rc_dev
->rxuhfmode
= true;
243 } else if (!strcmp(rx_mode
, "infrared")) {
244 rc_dev
->rxuhfmode
= false;
246 dev_err(dev
, "Unsupported rx mode [%s]\n", rx_mode
);
254 rc_dev
->sys_clock
= devm_clk_get(dev
, NULL
);
255 if (IS_ERR(rc_dev
->sys_clock
)) {
256 dev_err(dev
, "System clock not found\n");
257 ret
= PTR_ERR(rc_dev
->sys_clock
);
261 rc_dev
->irq
= platform_get_irq(pdev
, 0);
262 if (rc_dev
->irq
< 0) {
267 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
269 rc_dev
->base
= devm_ioremap_resource(dev
, res
);
270 if (IS_ERR(rc_dev
->base
)) {
271 ret
= PTR_ERR(rc_dev
->base
);
275 if (rc_dev
->rxuhfmode
)
276 rc_dev
->rx_base
= rc_dev
->base
+ 0x40;
278 rc_dev
->rx_base
= rc_dev
->base
;
281 rc_dev
->rstc
= reset_control_get(dev
, NULL
);
282 if (IS_ERR(rc_dev
->rstc
))
286 platform_set_drvdata(pdev
, rc_dev
);
287 st_rc_hardware_init(rc_dev
);
289 rdev
->driver_type
= RC_DRIVER_IR_RAW
;
290 rc_set_allowed_protocols(rdev
, RC_BIT_ALL
);
291 /* rx sampling rate is 10Mhz */
292 rdev
->rx_resolution
= 100;
293 rdev
->timeout
= US_TO_NS(MAX_SYMB_TIME
);
295 rdev
->open
= st_rc_open
;
296 rdev
->close
= st_rc_close
;
297 rdev
->driver_name
= IR_ST_NAME
;
298 rdev
->map_name
= RC_MAP_LIRC
;
299 rdev
->input_name
= "ST Remote Control Receiver";
301 /* enable wake via this device */
302 device_set_wakeup_capable(dev
, true);
303 device_set_wakeup_enable(dev
, true);
305 ret
= rc_register_device(rdev
);
310 if (devm_request_irq(dev
, rc_dev
->irq
, st_rc_rx_interrupt
,
311 IRQF_NO_SUSPEND
, IR_ST_NAME
, rc_dev
) < 0) {
312 dev_err(dev
, "IRQ %d register failed\n", rc_dev
->irq
);
318 * for LIRC_MODE_MODE2 or LIRC_MODE_PULSE or LIRC_MODE_RAW
319 * lircd expects a long space first before a signal train to sync.
321 st_rc_send_lirc_timeout(rdev
);
323 dev_info(dev
, "setup in %s mode\n", rc_dev
->rxuhfmode
? "UHF" : "IR");
327 rc_unregister_device(rdev
);
330 clk_disable_unprepare(rc_dev
->sys_clock
);
332 rc_free_device(rdev
);
333 dev_err(dev
, "Unable to register device (%d)\n", ret
);
338 static int st_rc_suspend(struct device
*dev
)
340 struct st_rc_device
*rc_dev
= dev_get_drvdata(dev
);
342 if (device_may_wakeup(dev
)) {
343 if (!enable_irq_wake(rc_dev
->irq
))
344 rc_dev
->irq_wake
= 1;
348 pinctrl_pm_select_sleep_state(dev
);
349 writel(0x00, rc_dev
->rx_base
+ IRB_RX_EN
);
350 writel(0x00, rc_dev
->rx_base
+ IRB_RX_INT_EN
);
351 clk_disable_unprepare(rc_dev
->sys_clock
);
353 reset_control_assert(rc_dev
->rstc
);
359 static int st_rc_resume(struct device
*dev
)
361 struct st_rc_device
*rc_dev
= dev_get_drvdata(dev
);
362 struct rc_dev
*rdev
= rc_dev
->rdev
;
364 if (rc_dev
->irq_wake
) {
365 disable_irq_wake(rc_dev
->irq
);
366 rc_dev
->irq_wake
= 0;
368 pinctrl_pm_select_default_state(dev
);
369 st_rc_hardware_init(rc_dev
);
371 writel(IRB_RX_INTS
, rc_dev
->rx_base
+ IRB_RX_INT_EN
);
372 writel(0x01, rc_dev
->rx_base
+ IRB_RX_EN
);
379 static SIMPLE_DEV_PM_OPS(st_rc_pm_ops
, st_rc_suspend
, st_rc_resume
);
383 static struct of_device_id st_rc_match
[] = {
384 { .compatible
= "st,comms-irb", },
388 MODULE_DEVICE_TABLE(of
, st_rc_match
);
391 static struct platform_driver st_rc_driver
= {
394 .owner
= THIS_MODULE
,
395 .of_match_table
= of_match_ptr(st_rc_match
),
400 .probe
= st_rc_probe
,
401 .remove
= st_rc_remove
,
404 module_platform_driver(st_rc_driver
);
406 MODULE_DESCRIPTION("RC Transceiver driver for STMicroelectronics platforms");
407 MODULE_AUTHOR("STMicroelectronics (R&D) Ltd");
408 MODULE_LICENSE("GPL");