419 lines
11 KiB
C
419 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2013 STMicroelectronics Limited
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* Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>
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*/
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#include <linux/kernel.h>
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#include <linux/clk.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/reset.h>
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#include <media/rc-core.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/pm_wakeirq.h>
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struct st_rc_device {
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struct device *dev;
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int irq;
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int irq_wake;
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struct clk *sys_clock;
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void __iomem *base; /* Register base address */
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void __iomem *rx_base;/* RX Register base address */
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struct rc_dev *rdev;
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bool overclocking;
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int sample_mult;
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int sample_div;
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bool rxuhfmode;
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struct reset_control *rstc;
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};
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/* Registers */
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#define IRB_SAMPLE_RATE_COMM 0x64 /* sample freq divisor*/
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#define IRB_CLOCK_SEL 0x70 /* clock select */
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#define IRB_CLOCK_SEL_STATUS 0x74 /* clock status */
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/* IRB IR/UHF receiver registers */
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#define IRB_RX_ON 0x40 /* pulse time capture */
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#define IRB_RX_SYS 0X44 /* sym period capture */
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#define IRB_RX_INT_EN 0x48 /* IRQ enable (R/W) */
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#define IRB_RX_INT_STATUS 0x4c /* IRQ status (R/W) */
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#define IRB_RX_EN 0x50 /* Receive enable */
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#define IRB_MAX_SYM_PERIOD 0x54 /* max sym value */
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#define IRB_RX_INT_CLEAR 0x58 /* overrun status */
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#define IRB_RX_STATUS 0x6c /* receive status */
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#define IRB_RX_NOISE_SUPPR 0x5c /* noise suppression */
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#define IRB_RX_POLARITY_INV 0x68 /* polarity inverter */
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/*
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* IRQ set: Enable full FIFO 1 -> bit 3;
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* Enable overrun IRQ 1 -> bit 2;
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* Enable last symbol IRQ 1 -> bit 1:
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* Enable RX interrupt 1 -> bit 0;
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*/
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#define IRB_RX_INTS 0x0f
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#define IRB_RX_OVERRUN_INT 0x04
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/* maximum symbol period (microsecs),timeout to detect end of symbol train */
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#define MAX_SYMB_TIME 0x5000
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#define IRB_SAMPLE_FREQ 10000000
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#define IRB_FIFO_NOT_EMPTY 0xff00
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#define IRB_OVERFLOW 0x4
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#define IRB_TIMEOUT 0xffff
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#define IR_ST_NAME "st-rc"
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static void st_rc_send_lirc_timeout(struct rc_dev *rdev)
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{
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struct ir_raw_event ev = { .timeout = true, .duration = rdev->timeout };
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ir_raw_event_store(rdev, &ev);
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}
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/*
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* RX graphical example to better understand the difference between ST IR block
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* output and standard definition used by LIRC (and most of the world!)
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*
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* mark mark
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* |-IRB_RX_ON-| |-IRB_RX_ON-|
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* ___ ___ ___ ___ ___ ___ _
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* | | | | | | | | | | | | |
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* | | | | | | space 0 | | | | | | space 1 |
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* _____| |__| |__| |____________________________| |__| |__| |_____________|
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*
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* |--------------- IRB_RX_SYS -------------|------ IRB_RX_SYS -------|
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*
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* |------------- encoding bit 0 -----------|---- encoding bit 1 -----|
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*
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* ST hardware returns mark (IRB_RX_ON) and total symbol time (IRB_RX_SYS), so
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* convert to standard mark/space we have to calculate space=(IRB_RX_SYS-mark)
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* The mark time represents the amount of time the carrier (usually 36-40kHz)
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* is detected.The above examples shows Pulse Width Modulation encoding where
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* bit 0 is represented by space>mark.
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*/
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static irqreturn_t st_rc_rx_interrupt(int irq, void *data)
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{
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unsigned long timeout;
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unsigned int symbol, mark = 0;
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struct st_rc_device *dev = data;
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int last_symbol = 0;
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u32 status, int_status;
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struct ir_raw_event ev = {};
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if (dev->irq_wake)
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pm_wakeup_event(dev->dev, 0);
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/* FIXME: is 10ms good enough ? */
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timeout = jiffies + msecs_to_jiffies(10);
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do {
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status = readl(dev->rx_base + IRB_RX_STATUS);
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if (!(status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW)))
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break;
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int_status = readl(dev->rx_base + IRB_RX_INT_STATUS);
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if (unlikely(int_status & IRB_RX_OVERRUN_INT)) {
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/* discard the entire collection in case of errors! */
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ir_raw_event_overflow(dev->rdev);
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dev_info(dev->dev, "IR RX overrun\n");
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writel(IRB_RX_OVERRUN_INT,
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dev->rx_base + IRB_RX_INT_CLEAR);
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continue;
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}
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symbol = readl(dev->rx_base + IRB_RX_SYS);
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mark = readl(dev->rx_base + IRB_RX_ON);
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if (symbol == IRB_TIMEOUT)
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last_symbol = 1;
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/* Ignore any noise */
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if ((mark > 2) && (symbol > 1)) {
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symbol -= mark;
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if (dev->overclocking) { /* adjustments to timings */
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symbol *= dev->sample_mult;
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symbol /= dev->sample_div;
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mark *= dev->sample_mult;
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mark /= dev->sample_div;
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}
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ev.duration = mark;
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ev.pulse = true;
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ir_raw_event_store(dev->rdev, &ev);
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if (!last_symbol) {
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ev.duration = symbol;
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ev.pulse = false;
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ir_raw_event_store(dev->rdev, &ev);
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} else {
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st_rc_send_lirc_timeout(dev->rdev);
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}
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}
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last_symbol = 0;
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} while (time_is_after_jiffies(timeout));
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writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_CLEAR);
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/* Empty software fifo */
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ir_raw_event_handle(dev->rdev);
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return IRQ_HANDLED;
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}
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static int st_rc_hardware_init(struct st_rc_device *dev)
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{
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int ret;
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int baseclock, freqdiff;
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unsigned int rx_max_symbol_per = MAX_SYMB_TIME;
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unsigned int rx_sampling_freq_div;
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/* Enable the IP */
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reset_control_deassert(dev->rstc);
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ret = clk_prepare_enable(dev->sys_clock);
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if (ret) {
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dev_err(dev->dev, "Failed to prepare/enable system clock\n");
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return ret;
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}
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baseclock = clk_get_rate(dev->sys_clock);
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/* IRB input pins are inverted internally from high to low. */
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writel(1, dev->rx_base + IRB_RX_POLARITY_INV);
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rx_sampling_freq_div = baseclock / IRB_SAMPLE_FREQ;
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writel(rx_sampling_freq_div, dev->base + IRB_SAMPLE_RATE_COMM);
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freqdiff = baseclock - (rx_sampling_freq_div * IRB_SAMPLE_FREQ);
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if (freqdiff) { /* over clocking, workout the adjustment factors */
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dev->overclocking = true;
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dev->sample_mult = 1000;
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dev->sample_div = baseclock / (10000 * rx_sampling_freq_div);
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rx_max_symbol_per = (rx_max_symbol_per * 1000)/dev->sample_div;
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}
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writel(rx_max_symbol_per, dev->rx_base + IRB_MAX_SYM_PERIOD);
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return 0;
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}
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static int st_rc_remove(struct platform_device *pdev)
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{
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struct st_rc_device *rc_dev = platform_get_drvdata(pdev);
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dev_pm_clear_wake_irq(&pdev->dev);
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device_init_wakeup(&pdev->dev, false);
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clk_disable_unprepare(rc_dev->sys_clock);
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rc_unregister_device(rc_dev->rdev);
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return 0;
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}
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static int st_rc_open(struct rc_dev *rdev)
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{
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struct st_rc_device *dev = rdev->priv;
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unsigned long flags;
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local_irq_save(flags);
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/* enable interrupts and receiver */
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writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_EN);
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writel(0x01, dev->rx_base + IRB_RX_EN);
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local_irq_restore(flags);
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return 0;
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}
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static void st_rc_close(struct rc_dev *rdev)
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{
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struct st_rc_device *dev = rdev->priv;
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/* disable interrupts and receiver */
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writel(0x00, dev->rx_base + IRB_RX_EN);
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writel(0x00, dev->rx_base + IRB_RX_INT_EN);
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}
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static int st_rc_probe(struct platform_device *pdev)
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{
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int ret = -EINVAL;
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struct rc_dev *rdev;
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struct device *dev = &pdev->dev;
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struct st_rc_device *rc_dev;
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struct device_node *np = pdev->dev.of_node;
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const char *rx_mode;
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rc_dev = devm_kzalloc(dev, sizeof(struct st_rc_device), GFP_KERNEL);
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if (!rc_dev)
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return -ENOMEM;
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rdev = rc_allocate_device(RC_DRIVER_IR_RAW);
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if (!rdev)
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return -ENOMEM;
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if (np && !of_property_read_string(np, "rx-mode", &rx_mode)) {
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if (!strcmp(rx_mode, "uhf")) {
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rc_dev->rxuhfmode = true;
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} else if (!strcmp(rx_mode, "infrared")) {
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rc_dev->rxuhfmode = false;
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} else {
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dev_err(dev, "Unsupported rx mode [%s]\n", rx_mode);
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goto err;
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}
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} else {
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goto err;
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}
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rc_dev->sys_clock = devm_clk_get(dev, NULL);
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if (IS_ERR(rc_dev->sys_clock)) {
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dev_err(dev, "System clock not found\n");
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ret = PTR_ERR(rc_dev->sys_clock);
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goto err;
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}
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rc_dev->irq = platform_get_irq(pdev, 0);
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if (rc_dev->irq < 0) {
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ret = rc_dev->irq;
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goto err;
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}
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rc_dev->base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(rc_dev->base)) {
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ret = PTR_ERR(rc_dev->base);
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goto err;
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}
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if (rc_dev->rxuhfmode)
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rc_dev->rx_base = rc_dev->base + 0x40;
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else
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rc_dev->rx_base = rc_dev->base;
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rc_dev->rstc = reset_control_get_optional_exclusive(dev, NULL);
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if (IS_ERR(rc_dev->rstc)) {
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ret = PTR_ERR(rc_dev->rstc);
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goto err;
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}
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rc_dev->dev = dev;
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platform_set_drvdata(pdev, rc_dev);
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ret = st_rc_hardware_init(rc_dev);
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if (ret)
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goto err;
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rdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
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/* rx sampling rate is 10Mhz */
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rdev->rx_resolution = 100;
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rdev->timeout = MAX_SYMB_TIME;
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rdev->priv = rc_dev;
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rdev->open = st_rc_open;
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rdev->close = st_rc_close;
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rdev->driver_name = IR_ST_NAME;
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rdev->map_name = RC_MAP_EMPTY;
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rdev->device_name = "ST Remote Control Receiver";
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ret = rc_register_device(rdev);
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if (ret < 0)
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goto clkerr;
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rc_dev->rdev = rdev;
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if (devm_request_irq(dev, rc_dev->irq, st_rc_rx_interrupt,
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0, IR_ST_NAME, rc_dev) < 0) {
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dev_err(dev, "IRQ %d register failed\n", rc_dev->irq);
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ret = -EINVAL;
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goto rcerr;
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}
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/* enable wake via this device */
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device_init_wakeup(dev, true);
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dev_pm_set_wake_irq(dev, rc_dev->irq);
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/*
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* for LIRC_MODE_MODE2 or LIRC_MODE_PULSE or LIRC_MODE_RAW
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* lircd expects a long space first before a signal train to sync.
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*/
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st_rc_send_lirc_timeout(rdev);
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dev_info(dev, "setup in %s mode\n", rc_dev->rxuhfmode ? "UHF" : "IR");
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return ret;
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rcerr:
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rc_unregister_device(rdev);
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rdev = NULL;
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clkerr:
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clk_disable_unprepare(rc_dev->sys_clock);
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err:
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rc_free_device(rdev);
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dev_err(dev, "Unable to register device (%d)\n", ret);
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return ret;
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}
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#ifdef CONFIG_PM_SLEEP
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static int st_rc_suspend(struct device *dev)
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{
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struct st_rc_device *rc_dev = dev_get_drvdata(dev);
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if (device_may_wakeup(dev)) {
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if (!enable_irq_wake(rc_dev->irq))
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rc_dev->irq_wake = 1;
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else
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return -EINVAL;
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} else {
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pinctrl_pm_select_sleep_state(dev);
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writel(0x00, rc_dev->rx_base + IRB_RX_EN);
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writel(0x00, rc_dev->rx_base + IRB_RX_INT_EN);
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clk_disable_unprepare(rc_dev->sys_clock);
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reset_control_assert(rc_dev->rstc);
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}
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return 0;
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}
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static int st_rc_resume(struct device *dev)
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{
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int ret;
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struct st_rc_device *rc_dev = dev_get_drvdata(dev);
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struct rc_dev *rdev = rc_dev->rdev;
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if (rc_dev->irq_wake) {
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disable_irq_wake(rc_dev->irq);
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rc_dev->irq_wake = 0;
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} else {
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pinctrl_pm_select_default_state(dev);
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ret = st_rc_hardware_init(rc_dev);
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if (ret)
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return ret;
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if (rdev->users) {
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writel(IRB_RX_INTS, rc_dev->rx_base + IRB_RX_INT_EN);
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writel(0x01, rc_dev->rx_base + IRB_RX_EN);
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}
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}
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return 0;
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}
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#endif
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static SIMPLE_DEV_PM_OPS(st_rc_pm_ops, st_rc_suspend, st_rc_resume);
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#ifdef CONFIG_OF
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static const struct of_device_id st_rc_match[] = {
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{ .compatible = "st,comms-irb", },
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{},
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};
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MODULE_DEVICE_TABLE(of, st_rc_match);
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#endif
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static struct platform_driver st_rc_driver = {
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.driver = {
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.name = IR_ST_NAME,
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.of_match_table = of_match_ptr(st_rc_match),
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.pm = &st_rc_pm_ops,
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},
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.probe = st_rc_probe,
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.remove = st_rc_remove,
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};
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module_platform_driver(st_rc_driver);
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MODULE_DESCRIPTION("RC Transceiver driver for STMicroelectronics platforms");
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MODULE_AUTHOR("STMicroelectronics (R&D) Ltd");
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MODULE_LICENSE("GPL");
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