rtl88x2CE_WiFi_linux driver

hc

2024-05-10 cde9070d9970eef1f7ec2360586c802a16230ad8

 kernel/drivers/media/rc/gpio-ir-tx.c
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@@ -1,14 +1,6 @@
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+// SPDX-License-Identifier: GPL-2.0-or-later
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 /*
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  * Copyright (C) 2017 Sean Young <sean@mess.org>
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- *
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- * This program is free software; you can redistribute it and/or modify
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- * it under the terms of the GNU General Public License version 2, or
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- * (at your option) any later version.
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- *
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- * This program is distributed in the hope that it will be useful,
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- * but WITHOUT ANY WARRANTY; without even the implied warranty of
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- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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- * GNU General Public License for more details.
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  */
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5
 
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 #include <linux/kernel.h>
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@@ -27,8 +19,6 @@
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 	struct gpio_desc *gpio;
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 	unsigned int carrier;
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 	unsigned int duty_cycle;
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-	/* we need a spinlock to hold the cpu while transmitting */
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-	spinlock_t lock;
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 };
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 static const struct of_device_id gpio_ir_tx_of_match[] = {
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@@ -50,7 +40,7 @@
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 {
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 	struct gpio_ir *gpio_ir = dev->priv;
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-	if (!carrier)
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+	if (carrier > 500000)
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 		return -EINVAL;
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45
 
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 	gpio_ir->carrier = carrier;
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@@ -58,11 +48,48 @@
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 	return 0;
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 }
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50
 
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-static int gpio_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
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-		      unsigned int count)
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+static void delay_until(ktime_t until)
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 {
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-	struct gpio_ir *gpio_ir = dev->priv;
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-	unsigned long flags;
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+	/*
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+	 * delta should never exceed 0.5 seconds (IR_MAX_DURATION) and on
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+	 * m68k ndelay(s64) does not compile; so use s32 rather than s64.
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+	 */
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+	s32 delta;
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+
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+	while (true) {
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+		delta = ktime_us_delta(until, ktime_get());
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+		if (delta <= 0)
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+			return;
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+
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+		/* udelay more than 1ms may not work */
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+		delta = min(delta, 1000);
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+		udelay(delta);
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+	}
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+}
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+
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+static void gpio_ir_tx_unmodulated(struct gpio_ir *gpio_ir, uint *txbuf,
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+				   uint count)
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+{
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+	ktime_t edge;
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+	int i;
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+
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+	local_irq_disable();
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+
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+	edge = ktime_get();
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+
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+	for (i = 0; i < count; i++) {
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+		gpiod_set_value(gpio_ir->gpio, !(i % 2));
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+
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+		edge = ktime_add_us(edge, txbuf[i]);
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+		delay_until(edge);
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+	}
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+
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+	gpiod_set_value(gpio_ir->gpio, 0);
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+}
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+
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+static void gpio_ir_tx_modulated(struct gpio_ir *gpio_ir, uint *txbuf,
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+				 uint count)
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+{
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 	ktime_t edge;
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 	/*
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 	 * delta should never exceed 0.5 seconds (IR_MAX_DURATION) and on
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@@ -78,7 +105,7 @@
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 	space = DIV_ROUND_CLOSEST((100 - gpio_ir->duty_cycle) *
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 				  (NSEC_PER_SEC / 100), gpio_ir->carrier);
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107
 
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-	spin_lock_irqsave(&gpio_ir->lock, flags);
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+	local_irq_disable();
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 	edge = ktime_get();
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111
 
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@@ -86,9 +113,7 @@
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 		if (i % 2) {
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 			// space
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 			edge = ktime_add_us(edge, txbuf[i]);
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-			delta = ktime_us_delta(edge, ktime_get());
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-			if (delta > 0)
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-				udelay(delta);
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+			delay_until(edge);
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 		} else {
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 			// pulse
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 			ktime_t last = ktime_add_us(edge, txbuf[i]);
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@@ -111,8 +136,20 @@
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 			edge = last;
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 		}
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 	}
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+}
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-	spin_unlock_irqrestore(&gpio_ir->lock, flags);
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+static int gpio_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
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+		      unsigned int count)
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+{
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+	struct gpio_ir *gpio_ir = dev->priv;
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+	unsigned long flags;
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+
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+	local_irq_save(flags);
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+	if (gpio_ir->carrier)
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+		gpio_ir_tx_modulated(gpio_ir, txbuf, count);
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+	else
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+		gpio_ir_tx_unmodulated(gpio_ir, txbuf, count);
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+	local_irq_restore(flags);
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 	return count;
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 }
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@@ -148,7 +185,6 @@
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185
 
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 	gpio_ir->carrier = 38000;
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 	gpio_ir->duty_cycle = 50;
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-	spin_lock_init(&gpio_ir->lock);
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188
 
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 	rc = devm_rc_register_device(&pdev->dev, rcdev);
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 	if (rc < 0)