[media] media: st-rc: Add ST remote control driver (80f93c7b) · Commits · 戴 / test

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

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		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

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		@@ -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

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		@@ -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

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		/*
		* 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");

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