Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 80f93c7b authored by Srinivas Kandagatla's avatar Srinivas Kandagatla Committed by Mauro Carvalho Chehab
Browse files

[media] media: st-rc: Add ST remote control driver 



This patch adds support to ST RC driver, which is basically a IR/UHF
receiver and transmitter. This IP (IRB) is common across all the ST
parts for settop box platforms. IRB is embedded in ST COMMS IP block.
It supports both Rx & Tx functionality.
This driver adds only Rx functionality via LIRC codec.

Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@st.com>
Acked-by: default avatarSean Young <sean@mess.org>
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent 8ab1aa87

Documentation/devicetree/bindings/media/st-rc.txt

0 → 100644
+29 −0
Original line number Diff line number Diff line 
Device-Tree bindings for ST IRB IP



Required properties:

	- compatible: Should contain "st,comms-irb".

	- reg: Base physical address of the controller and length of memory

	  mapped region.

	- interrupts: interrupt-specifier for the sole interrupt generated by

	  the device. The interrupt specifier format depends on the interrupt

	  controller parent.

	- rx-mode: can be "infrared" or "uhf". This property specifies the L1

	  protocol used for receiving remote control signals. rx-mode should

	  be present iff the rx pins are wired up.

	- tx-mode: should be "infrared". This property specifies the L1

	  protocol used for transmitting remote control signals. tx-mode should

	  be present iff the tx pins are wired up.



Optional properties:

	- pinctrl-names, pinctrl-0: the pincontrol settings to configure muxing

	  properly for IRB pins.

	- clocks : phandle with clock-specifier pair for IRB.



Example node:



	rc: rc@fe518000 {

		compatible	= "st,comms-irb";

		reg		= <0xfe518000 0x234>;

		interrupts	= <0 203 0>;

		rx-mode		= "infrared";

	};

drivers/media/rc/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -322,4 +322,14 @@ config IR_GPIO_CIR 
	   To compile this driver as a module, choose M here: the module will

	   be called gpio-ir-recv.



config RC_ST

	tristate "ST remote control receiver"

	depends on ARCH_STI && RC_CORE

	help

	 Say Y here if you want support for ST remote control driver

	 which allows both IR and UHF RX.

	 The driver passes raw pulse and space information to the LIRC decoder.



	 If you're not sure, select N here.



endif #RC_DEVICES

drivers/media/rc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -30,3 +30,4 @@ obj-$(CONFIG_RC_LOOPBACK) += rc-loopback.o 
obj-$(CONFIG_IR_GPIO_CIR) += gpio-ir-recv.o

obj-$(CONFIG_IR_IGUANA) += iguanair.o

obj-$(CONFIG_IR_TTUSBIR) += ttusbir.o

obj-$(CONFIG_RC_ST) += st_rc.o

drivers/media/rc/st_rc.c

0 → 100644
+395 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2013 STMicroelectronics Limited

 * Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 */

#include <linux/kernel.h>

#include <linux/clk.h>

#include <linux/interrupt.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <media/rc-core.h>

#include <linux/pinctrl/consumer.h>



struct st_rc_device {

	struct device			*dev;

	int				irq;

	int				irq_wake;

	struct clk			*sys_clock;

	void				*base;	/* Register base address */

	void				*rx_base;/* RX Register base address */

	struct rc_dev			*rdev;

	bool				overclocking;

	int				sample_mult;

	int				sample_div;

	bool				rxuhfmode;

};



/* Registers */

#define IRB_SAMPLE_RATE_COMM	0x64	/* sample freq divisor*/

#define IRB_CLOCK_SEL		0x70	/* clock select       */

#define IRB_CLOCK_SEL_STATUS	0x74	/* clock status       */

/* IRB IR/UHF receiver registers */

#define IRB_RX_ON               0x40	/* pulse time capture */

#define IRB_RX_SYS              0X44	/* sym period capture */

#define IRB_RX_INT_EN           0x48	/* IRQ enable (R/W)   */

#define IRB_RX_INT_STATUS       0x4c	/* IRQ status (R/W)   */

#define IRB_RX_EN               0x50	/* Receive enable     */

#define IRB_MAX_SYM_PERIOD      0x54	/* max sym value      */

#define IRB_RX_INT_CLEAR        0x58	/* overrun status     */

#define IRB_RX_STATUS           0x6c	/* receive status     */

#define IRB_RX_NOISE_SUPPR      0x5c	/* noise suppression  */

#define IRB_RX_POLARITY_INV     0x68	/* polarity inverter  */



/**

 * IRQ set: Enable full FIFO                 1  -> bit  3;

 *          Enable overrun IRQ               1  -> bit  2;

 *          Enable last symbol IRQ           1  -> bit  1:

 *          Enable RX interrupt              1  -> bit  0;

 */

#define IRB_RX_INTS		0x0f

#define IRB_RX_OVERRUN_INT	0x04

 /* maximum symbol period (microsecs),timeout to detect end of symbol train */

#define MAX_SYMB_TIME		0x5000

#define IRB_SAMPLE_FREQ		10000000

#define	IRB_FIFO_NOT_EMPTY	0xff00

#define IRB_OVERFLOW		0x4

#define IRB_TIMEOUT		0xffff

#define IR_ST_NAME "st-rc"



static void st_rc_send_lirc_timeout(struct rc_dev *rdev)

{

	DEFINE_IR_RAW_EVENT(ev);

	ev.timeout = true;

	ir_raw_event_store(rdev, &ev);

}



/**

 * RX graphical example to better understand the difference between ST IR block

 * output and standard definition used by LIRC (and most of the world!)

 *

 *           mark                                     mark

 *      |-IRB_RX_ON-|                            |-IRB_RX_ON-|

 *      ___  ___  ___                            ___  ___  ___             _

 *      | |  | |  | |                            | |  | |  | |             |

 *      | |  | |  | |         space 0            | |  | |  | |   space 1   |

 * _____| |__| |__| |____________________________| |__| |__| |_____________|

 *

 *      |--------------- IRB_RX_SYS -------------|------ IRB_RX_SYS -------|

 *

 *      |------------- encoding bit 0 -----------|---- encoding bit 1 -----|

 *

 * ST hardware returns mark (IRB_RX_ON) and total symbol time (IRB_RX_SYS), so

 * convert to standard mark/space we have to calculate space=(IRB_RX_SYS-mark)

 * The mark time represents the amount of time the carrier (usually 36-40kHz)

 * is detected.The above examples shows Pulse Width Modulation encoding where

 * bit 0 is represented by space>mark.

 */



static irqreturn_t st_rc_rx_interrupt(int irq, void *data)

{

	unsigned int symbol, mark = 0;

	struct st_rc_device *dev = data;

	int last_symbol = 0;

	u32 status;

	DEFINE_IR_RAW_EVENT(ev);



	if (dev->irq_wake)

		pm_wakeup_event(dev->dev, 0);



	status  = readl(dev->rx_base + IRB_RX_STATUS);



	while (status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW)) {

		u32 int_status = readl(dev->rx_base + IRB_RX_INT_STATUS);

		if (unlikely(int_status & IRB_RX_OVERRUN_INT)) {

			/* discard the entire collection in case of errors!  */

			ir_raw_event_reset(dev->rdev);

			dev_info(dev->dev, "IR RX overrun\n");

			writel(IRB_RX_OVERRUN_INT,

					dev->rx_base + IRB_RX_INT_CLEAR);

			continue;

		}



		symbol = readl(dev->rx_base + IRB_RX_SYS);

		mark = readl(dev->rx_base + IRB_RX_ON);



		if (symbol == IRB_TIMEOUT)

			last_symbol = 1;



		 /* Ignore any noise */

		if ((mark > 2) && (symbol > 1)) {

			symbol -= mark;

			if (dev->overclocking) { /* adjustments to timings */

				symbol *= dev->sample_mult;

				symbol /= dev->sample_div;

				mark *= dev->sample_mult;

				mark /= dev->sample_div;

			}



			ev.duration = US_TO_NS(mark);

			ev.pulse = true;

			ir_raw_event_store(dev->rdev, &ev);



			if (!last_symbol) {

				ev.duration = US_TO_NS(symbol);

				ev.pulse = false;

				ir_raw_event_store(dev->rdev, &ev);

			} else  {

				st_rc_send_lirc_timeout(dev->rdev);

			}



		}

		last_symbol = 0;

		status  = readl(dev->rx_base + IRB_RX_STATUS);

	}



	writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_CLEAR);



	/* Empty software fifo */

	ir_raw_event_handle(dev->rdev);

	return IRQ_HANDLED;

}



static void st_rc_hardware_init(struct st_rc_device *dev)

{

	int baseclock, freqdiff;

	unsigned int rx_max_symbol_per = MAX_SYMB_TIME;

	unsigned int rx_sampling_freq_div;



	clk_prepare_enable(dev->sys_clock);

	baseclock = clk_get_rate(dev->sys_clock);



	/* IRB input pins are inverted internally from high to low. */

	writel(1, dev->rx_base + IRB_RX_POLARITY_INV);



	rx_sampling_freq_div = baseclock / IRB_SAMPLE_FREQ;

	writel(rx_sampling_freq_div, dev->base + IRB_SAMPLE_RATE_COMM);



	freqdiff = baseclock - (rx_sampling_freq_div * IRB_SAMPLE_FREQ);

	if (freqdiff) { /* over clocking, workout the adjustment factors */

		dev->overclocking = true;

		dev->sample_mult = 1000;

		dev->sample_div = baseclock / (10000 * rx_sampling_freq_div);

		rx_max_symbol_per = (rx_max_symbol_per * 1000)/dev->sample_div;

	}



	writel(rx_max_symbol_per, dev->rx_base + IRB_MAX_SYM_PERIOD);

}



static int st_rc_remove(struct platform_device *pdev)

{

	struct st_rc_device *rc_dev = platform_get_drvdata(pdev);

	clk_disable_unprepare(rc_dev->sys_clock);

	rc_unregister_device(rc_dev->rdev);

	return 0;

}



static int st_rc_open(struct rc_dev *rdev)

{

	struct st_rc_device *dev = rdev->priv;

	unsigned long flags;

	local_irq_save(flags);

	/* enable interrupts and receiver */

	writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_EN);

	writel(0x01, dev->rx_base + IRB_RX_EN);

	local_irq_restore(flags);



	return 0;

}



static void st_rc_close(struct rc_dev *rdev)

{

	struct st_rc_device *dev = rdev->priv;

	/* disable interrupts and receiver */

	writel(0x00, dev->rx_base + IRB_RX_EN);

	writel(0x00, dev->rx_base + IRB_RX_INT_EN);

}



static int st_rc_probe(struct platform_device *pdev)

{

	int ret = -EINVAL;

	struct rc_dev *rdev;

	struct device *dev = &pdev->dev;

	struct resource *res;

	struct st_rc_device *rc_dev;

	struct device_node *np = pdev->dev.of_node;

	const char *rx_mode;



	rc_dev = devm_kzalloc(dev, sizeof(struct st_rc_device), GFP_KERNEL);



	if (!rc_dev)

		return -ENOMEM;



	rdev = rc_allocate_device();



	if (!rdev)

		return -ENOMEM;



	if (np && !of_property_read_string(np, "rx-mode", &rx_mode)) {



		if (!strcmp(rx_mode, "uhf")) {

			rc_dev->rxuhfmode = true;

		} else if (!strcmp(rx_mode, "infrared")) {

			rc_dev->rxuhfmode = false;

		} else {

			dev_err(dev, "Unsupported rx mode [%s]\n", rx_mode);

			goto err;

		}



	} else {

		goto err;

	}



	rc_dev->sys_clock = devm_clk_get(dev, NULL);

	if (IS_ERR(rc_dev->sys_clock)) {

		dev_err(dev, "System clock not found\n");

		ret = PTR_ERR(rc_dev->sys_clock);

		goto err;

	}



	rc_dev->irq = platform_get_irq(pdev, 0);

	if (rc_dev->irq < 0) {

		ret = rc_dev->irq;

		goto err;

	}



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);



	rc_dev->base = devm_ioremap_resource(dev, res);

	if (IS_ERR(rc_dev->base)) {

		ret = PTR_ERR(rc_dev->base);

		goto err;

	}



	if (rc_dev->rxuhfmode)

		rc_dev->rx_base = rc_dev->base + 0x40;

	else

		rc_dev->rx_base = rc_dev->base;



	rc_dev->dev = dev;

	platform_set_drvdata(pdev, rc_dev);

	st_rc_hardware_init(rc_dev);



	rdev->driver_type = RC_DRIVER_IR_RAW;

	rdev->allowed_protos = RC_BIT_ALL;

	/* rx sampling rate is 10Mhz */

	rdev->rx_resolution = 100;

	rdev->timeout = US_TO_NS(MAX_SYMB_TIME);

	rdev->priv = rc_dev;

	rdev->open = st_rc_open;

	rdev->close = st_rc_close;

	rdev->driver_name = IR_ST_NAME;

	rdev->map_name = RC_MAP_LIRC;

	rdev->input_name = "ST Remote Control Receiver";



	/* enable wake via this device */

	device_set_wakeup_capable(dev, true);

	device_set_wakeup_enable(dev, true);



	ret = rc_register_device(rdev);

	if (ret < 0)

		goto clkerr;



	rc_dev->rdev = rdev;

	if (devm_request_irq(dev, rc_dev->irq, st_rc_rx_interrupt,

			IRQF_NO_SUSPEND, IR_ST_NAME, rc_dev) < 0) {

		dev_err(dev, "IRQ %d register failed\n", rc_dev->irq);

		ret = -EINVAL;

		goto rcerr;

	}



	/**

	 * for LIRC_MODE_MODE2 or LIRC_MODE_PULSE or LIRC_MODE_RAW

	 * lircd expects a long space first before a signal train to sync.

	 */

	st_rc_send_lirc_timeout(rdev);



	dev_info(dev, "setup in %s mode\n", rc_dev->rxuhfmode ? "UHF" : "IR");



	return ret;

rcerr:

	rc_unregister_device(rdev);

	rdev = NULL;

clkerr:

	clk_disable_unprepare(rc_dev->sys_clock);

err:

	rc_free_device(rdev);

	dev_err(dev, "Unable to register device (%d)\n", ret);

	return ret;

}



#ifdef CONFIG_PM

static int st_rc_suspend(struct device *dev)

{

	struct st_rc_device *rc_dev = dev_get_drvdata(dev);



	if (device_may_wakeup(dev)) {

		if (!enable_irq_wake(rc_dev->irq))

			rc_dev->irq_wake = 1;

		else

			return -EINVAL;

	} else {

		pinctrl_pm_select_sleep_state(dev);

		writel(0x00, rc_dev->rx_base + IRB_RX_EN);

		writel(0x00, rc_dev->rx_base + IRB_RX_INT_EN);

		clk_disable_unprepare(rc_dev->sys_clock);

	}



	return 0;

}



static int st_rc_resume(struct device *dev)

{

	struct st_rc_device *rc_dev = dev_get_drvdata(dev);

	struct rc_dev	*rdev = rc_dev->rdev;



	if (rc_dev->irq_wake) {

		disable_irq_wake(rc_dev->irq);

		rc_dev->irq_wake = 0;

	} else {

		pinctrl_pm_select_default_state(dev);

		st_rc_hardware_init(rc_dev);

		if (rdev->users) {

			writel(IRB_RX_INTS, rc_dev->rx_base + IRB_RX_INT_EN);

			writel(0x01, rc_dev->rx_base + IRB_RX_EN);

		}

	}



	return 0;

}



static SIMPLE_DEV_PM_OPS(st_rc_pm_ops, st_rc_suspend, st_rc_resume);

#endif



#ifdef CONFIG_OF

static struct of_device_id st_rc_match[] = {

	{ .compatible = "st,comms-irb", },

	{},

};



MODULE_DEVICE_TABLE(of, st_rc_match);

#endif



static struct platform_driver st_rc_driver = {

	.driver = {

		.name = IR_ST_NAME,

		.owner	= THIS_MODULE,

		.of_match_table = of_match_ptr(st_rc_match),

#ifdef CONFIG_PM

		.pm     = &st_rc_pm_ops,

#endif

	},

	.probe = st_rc_probe,

	.remove = st_rc_remove,

};



module_platform_driver(st_rc_driver);



MODULE_DESCRIPTION("RC Transceiver driver for STMicroelectronics platforms");

MODULE_AUTHOR("STMicroelectronics (R&D) Ltd");

MODULE_LICENSE("GPL");