[media] media: rc: Introduce RX51 IR transmitter driver

This is the driver for the IR transmitter diode found on the Nokia
N900 (also known as RX51) device. The driver is mostly the same as
found in the original 2.6.28 based kernel that comes with the device.

The following modifications have been made compared to the original
driver version:

- Adopt to the changes that has happen in the kernel during the past
  five years, such as the change in the include paths

- The OMAP DM-timers require much more care nowadays. The timers need
  to be enabled and disabled or otherwise many actions fail. Timers
  must not be freed without first stopping them or otherwise the timer
  cannot be requested again.

The code has been tested with sending IR codes with N900 device
running Debian userland. The device receiving the codes was Anysee
DVB-C USB receiver.

Signed-off-by: Timo Kokkonen <timo.t.kokkonen@iki.fi>
Cc: Tony Lindgren <tony@atomide.com>
Cc: linux-omap@vger.kernel.org
Cc: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 507 insertions, 0 deletions

diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
index 64be610fe27d..016f9ab1c1e9 100644
--- a/drivers/media/rc/Kconfig
+++ b/drivers/media/rc/Kconfig
@@ -287,6 +287,16 @@ config IR_TTUSBIR
 	   To compile this driver as a module, choose M here: the module will
 	   be called ttusbir.
 
+config IR_RX51
+	tristate "Nokia N900 IR transmitter diode
+	depends on MACH_NOKIA_RX51 && OMAP_DM_TIMER
+	---help---
+	   Say Y or M here if you want to enable support for the IR
+	   transmitter diode built in the Nokia N900 (RX51) device.
+
+	   The driver uses omap DM timers for gereating the carrier
+	   wave and pulses.
+
 config RC_LOOPBACK
 	tristate "Remote Control Loopback Driver"
 	depends on RC_CORE
diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
index 66c8baed565d..56bacf07b361 100644
--- a/drivers/media/rc/Makefile
+++ b/drivers/media/rc/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_IR_FINTEK) += fintek-cir.o
 obj-$(CONFIG_IR_NUVOTON) += nuvoton-cir.o
 obj-$(CONFIG_IR_ENE) += ene_ir.o
 obj-$(CONFIG_IR_REDRAT3) += redrat3.o
+obj-$(CONFIG_IR_RX51) += ir-rx51.o
 obj-$(CONFIG_IR_STREAMZAP) += streamzap.o
 obj-$(CONFIG_IR_WINBOND_CIR) += winbond-cir.o
 obj-$(CONFIG_RC_LOOPBACK) += rc-loopback.o
diff --git a/drivers/media/rc/ir-rx51.c b/drivers/media/rc/ir-rx51.c
new file mode 100644
index 000000000000..9487dd33a89a
--- /dev/null
+++ b/drivers/media/rc/ir-rx51.c
@@ -0,0 +1,496 @@
+/*
+ *  Copyright (C) 2008 Nokia Corporation
+ *
+ *  Based on lirc_serial.c
+ *
+ *  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.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/uaccess.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#include <plat/dmtimer.h>
+#include <plat/clock.h>
+#include <plat/omap-pm.h>
+
+#include <media/lirc.h>
+#include <media/lirc_dev.h>
+#include <media/ir-rx51.h>
+
+#define LIRC_RX51_DRIVER_FEATURES (LIRC_CAN_SET_SEND_DUTY_CYCLE |	\
+				   LIRC_CAN_SET_SEND_CARRIER |		\
+				   LIRC_CAN_SEND_PULSE)
+
+#define DRIVER_NAME "lirc_rx51"
+
+#define WBUF_LEN 256
+
+#define TIMER_MAX_VALUE 0xffffffff
+
+struct lirc_rx51 {
+	struct omap_dm_timer *pwm_timer;
+	struct omap_dm_timer *pulse_timer;
+	struct device	     *dev;
+	struct lirc_rx51_platform_data *pdata;
+	wait_queue_head_t     wqueue;
+
+	unsigned long	fclk_khz;
+	unsigned int	freq;		/* carrier frequency */
+	unsigned int	duty_cycle;	/* carrier duty cycle */
+	unsigned int	irq_num;
+	unsigned int	match;
+	int		wbuf[WBUF_LEN];
+	int		wbuf_index;
+	unsigned long	device_is_open;
+	unsigned int	pwm_timer_num;
+};
+
+static void lirc_rx51_on(struct lirc_rx51 *lirc_rx51)
+{
+	omap_dm_timer_set_pwm(lirc_rx51->pwm_timer, 0, 1,
+			      OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE);
+}
+
+static void lirc_rx51_off(struct lirc_rx51 *lirc_rx51)
+{
+	omap_dm_timer_set_pwm(lirc_rx51->pwm_timer, 0, 1,
+			      OMAP_TIMER_TRIGGER_NONE);
+}
+
+static int init_timing_params(struct lirc_rx51 *lirc_rx51)
+{
+	u32 load, match;
+
+	load = -(lirc_rx51->fclk_khz * 1000 / lirc_rx51->freq);
+	match = -(lirc_rx51->duty_cycle * -load / 100);
+	omap_dm_timer_set_load(lirc_rx51->pwm_timer, 1, load);
+	omap_dm_timer_set_match(lirc_rx51->pwm_timer, 1, match);
+	omap_dm_timer_write_counter(lirc_rx51->pwm_timer, TIMER_MAX_VALUE - 2);
+	omap_dm_timer_start(lirc_rx51->pwm_timer);
+	omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer, 0);
+	omap_dm_timer_start(lirc_rx51->pulse_timer);
+
+	lirc_rx51->match = 0;
+
+	return 0;
+}
+
+#define tics_after(a, b) ((long)(b) - (long)(a) < 0)
+
+static int pulse_timer_set_timeout(struct lirc_rx51 *lirc_rx51, int usec)
+{
+	int counter;
+
+	BUG_ON(usec < 0);
+
+	if (lirc_rx51->match == 0)
+		counter = omap_dm_timer_read_counter(lirc_rx51->pulse_timer);
+	else
+		counter = lirc_rx51->match;
+
+	counter += (u32)(lirc_rx51->fclk_khz * usec / (1000));
+	omap_dm_timer_set_match(lirc_rx51->pulse_timer, 1, counter);
+	omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer,
+				     OMAP_TIMER_INT_MATCH);
+	if (tics_after(omap_dm_timer_read_counter(lirc_rx51->pulse_timer),
+		       counter)) {
+		return 1;
+	}
+	return 0;
+}
+
+static irqreturn_t lirc_rx51_interrupt_handler(int irq, void *ptr)
+{
+	unsigned int retval;
+	struct lirc_rx51 *lirc_rx51 = ptr;
+
+	retval = omap_dm_timer_read_status(lirc_rx51->pulse_timer);
+	if (!retval)
+		return IRQ_NONE;
+
+	if ((retval & ~OMAP_TIMER_INT_MATCH))
+		dev_err_ratelimited(lirc_rx51->dev,
+				": Unexpected interrupt source: %x\n", retval);
+
+	omap_dm_timer_write_status(lirc_rx51->pulse_timer, 7);
+	if (lirc_rx51->wbuf_index < 0) {
+		dev_err_ratelimited(lirc_rx51->dev,
+				": BUG wbuf_index has value of %i\n",
+				lirc_rx51->wbuf_index);
+		goto end;
+	}
+
+	/*
+	 * If we happen to hit an odd latency spike, loop through the
+	 * pulses until we catch up.
+	 */
+	do {
+		if (lirc_rx51->wbuf_index >= WBUF_LEN)
+			goto end;
+		if (lirc_rx51->wbuf[lirc_rx51->wbuf_index] == -1)
+			goto end;
+
+		if (lirc_rx51->wbuf_index % 2)
+			lirc_rx51_off(lirc_rx51);
+		else
+			lirc_rx51_on(lirc_rx51);
+
+		retval = pulse_timer_set_timeout(lirc_rx51,
+					lirc_rx51->wbuf[lirc_rx51->wbuf_index]);
+		lirc_rx51->wbuf_index++;
+
+	} while (retval);
+
+	return IRQ_HANDLED;
+end:
+	/* Stop TX here */
+	lirc_rx51_off(lirc_rx51);
+	lirc_rx51->wbuf_index = -1;
+	omap_dm_timer_stop(lirc_rx51->pwm_timer);
+	omap_dm_timer_stop(lirc_rx51->pulse_timer);
+	omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer, 0);
+	wake_up_interruptible(&lirc_rx51->wqueue);
+
+	return IRQ_HANDLED;
+}
+
+static int lirc_rx51_init_port(struct lirc_rx51 *lirc_rx51)
+{
+	struct clk *clk_fclk;
+	int retval, pwm_timer = lirc_rx51->pwm_timer_num;
+
+	lirc_rx51->pwm_timer = omap_dm_timer_request_specific(pwm_timer);
+	if (lirc_rx51->pwm_timer == NULL) {
+		dev_err(lirc_rx51->dev, ": Error requesting GPT%d timer\n",
+			pwm_timer);
+		return -EBUSY;
+	}
+
+	lirc_rx51->pulse_timer = omap_dm_timer_request();
+	if (lirc_rx51->pulse_timer == NULL) {
+		dev_err(lirc_rx51->dev, ": Error requesting pulse timer\n");
+		retval = -EBUSY;
+		goto err1;
+	}
+
+	omap_dm_timer_set_source(lirc_rx51->pwm_timer, OMAP_TIMER_SRC_SYS_CLK);
+	omap_dm_timer_set_source(lirc_rx51->pulse_timer,
+				OMAP_TIMER_SRC_SYS_CLK);
+
+	omap_dm_timer_enable(lirc_rx51->pwm_timer);
+	omap_dm_timer_enable(lirc_rx51->pulse_timer);
+
+	lirc_rx51->irq_num = omap_dm_timer_get_irq(lirc_rx51->pulse_timer);
+	retval = request_irq(lirc_rx51->irq_num, lirc_rx51_interrupt_handler,
+			     IRQF_DISABLED | IRQF_SHARED,
+			     "lirc_pulse_timer", lirc_rx51);
+	if (retval) {
+		dev_err(lirc_rx51->dev, ": Failed to request interrupt line\n");
+		goto err2;
+	}
+
+	clk_fclk = omap_dm_timer_get_fclk(lirc_rx51->pwm_timer);
+	lirc_rx51->fclk_khz = clk_fclk->rate / 1000;
+
+	return 0;
+
+err2:
+	omap_dm_timer_free(lirc_rx51->pulse_timer);
+err1:
+	omap_dm_timer_free(lirc_rx51->pwm_timer);
+
+	return retval;
+}
+
+static int lirc_rx51_free_port(struct lirc_rx51 *lirc_rx51)
+{
+	omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer, 0);
+	free_irq(lirc_rx51->irq_num, lirc_rx51);
+	lirc_rx51_off(lirc_rx51);
+	omap_dm_timer_disable(lirc_rx51->pwm_timer);
+	omap_dm_timer_disable(lirc_rx51->pulse_timer);
+	omap_dm_timer_free(lirc_rx51->pwm_timer);
+	omap_dm_timer_free(lirc_rx51->pulse_timer);
+	lirc_rx51->wbuf_index = -1;
+
+	return 0;
+}
+
+static ssize_t lirc_rx51_write(struct file *file, const char *buf,
+			  size_t n, loff_t *ppos)
+{
+	int count, i;
+	struct lirc_rx51 *lirc_rx51 = file->private_data;
+
+	if (n % sizeof(int))
+		return -EINVAL;
+
+	count = n / sizeof(int);
+	if ((count > WBUF_LEN) || (count % 2 == 0))
+		return -EINVAL;
+
+	/* Wait any pending transfers to finish */
+	wait_event_interruptible(lirc_rx51->wqueue, lirc_rx51->wbuf_index < 0);
+
+	if (copy_from_user(lirc_rx51->wbuf, buf, n))
+		return -EFAULT;
+
+	/* Sanity check the input pulses */
+	for (i = 0; i < count; i++)
+		if (lirc_rx51->wbuf[i] < 0)
+			return -EINVAL;
+
+	init_timing_params(lirc_rx51);
+	if (count < WBUF_LEN)
+		lirc_rx51->wbuf[count] = -1; /* Insert termination mark */
+
+	/*
+	 * Adjust latency requirements so the device doesn't go in too
+	 * deep sleep states
+	 */
+	lirc_rx51->pdata->set_max_mpu_wakeup_lat(lirc_rx51->dev, 50);
+
+	lirc_rx51_on(lirc_rx51);
+	lirc_rx51->wbuf_index = 1;
+	pulse_timer_set_timeout(lirc_rx51, lirc_rx51->wbuf[0]);
+
+	/*
+	 * Don't return back to the userspace until the transfer has
+	 * finished
+	 */
+	wait_event_interruptible(lirc_rx51->wqueue, lirc_rx51->wbuf_index < 0);
+
+	/* We can sleep again */
+	lirc_rx51->pdata->set_max_mpu_wakeup_lat(lirc_rx51->dev, -1);
+
+	return n;
+}
+
+static long lirc_rx51_ioctl(struct file *filep,
+			unsigned int cmd, unsigned long arg)
+{
+	int result;
+	unsigned long value;
+	unsigned int ivalue;
+	struct lirc_rx51 *lirc_rx51 = filep->private_data;
+
+	switch (cmd) {
+	case LIRC_GET_SEND_MODE:
+		result = put_user(LIRC_MODE_PULSE, (unsigned long *)arg);
+		if (result)
+			return result;
+		break;
+
+	case LIRC_SET_SEND_MODE:
+		result = get_user(value, (unsigned long *)arg);
+		if (result)
+			return result;
+
+		/* only LIRC_MODE_PULSE supported */
+		if (value != LIRC_MODE_PULSE)
+			return -ENOSYS;
+		break;
+
+	case LIRC_GET_REC_MODE:
+		result = put_user(0, (unsigned long *) arg);
+		if (result)
+			return result;
+		break;
+
+	case LIRC_GET_LENGTH:
+		return -ENOSYS;
+		break;
+
+	case LIRC_SET_SEND_DUTY_CYCLE:
+		result = get_user(ivalue, (unsigned int *) arg);
+		if (result)
+			return result;
+
+		if (ivalue <= 0 || ivalue > 100) {
+			dev_err(lirc_rx51->dev, ": invalid duty cycle %d\n",
+				ivalue);
+			return -EINVAL;
+		}
+
+		lirc_rx51->duty_cycle = ivalue;
+		break;
+
+	case LIRC_SET_SEND_CARRIER:
+		result = get_user(ivalue, (unsigned int *) arg);
+		if (result)
+			return result;
+
+		if (ivalue > 500000 || ivalue < 20000) {
+			dev_err(lirc_rx51->dev, ": invalid carrier freq %d\n",
+				ivalue);
+			return -EINVAL;
+		}
+
+		lirc_rx51->freq = ivalue;
+		break;
+
+	case LIRC_GET_FEATURES:
+		result = put_user(LIRC_RX51_DRIVER_FEATURES,
+				  (unsigned long *) arg);
+		if (result)
+			return result;
+		break;
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+static int lirc_rx51_open(struct inode *inode, struct file *file)
+{
+	struct lirc_rx51 *lirc_rx51 = lirc_get_pdata(file);
+	BUG_ON(!lirc_rx51);
+
+	file->private_data = lirc_rx51;
+
+	if (test_and_set_bit(1, &lirc_rx51->device_is_open))
+		return -EBUSY;
+
+	return lirc_rx51_init_port(lirc_rx51);
+}
+
+static int lirc_rx51_release(struct inode *inode, struct file *file)
+{
+	struct lirc_rx51 *lirc_rx51 = file->private_data;
+
+	lirc_rx51_free_port(lirc_rx51);
+
+	clear_bit(1, &lirc_rx51->device_is_open);
+
+	return 0;
+}
+
+static struct lirc_rx51 lirc_rx51 = {
+	.freq		= 38000,
+	.duty_cycle	= 50,
+	.wbuf_index	= -1,
+};
+
+static const struct file_operations lirc_fops = {
+	.owner		= THIS_MODULE,
+	.write		= lirc_rx51_write,
+	.unlocked_ioctl	= lirc_rx51_ioctl,
+	.read		= lirc_dev_fop_read,
+	.poll		= lirc_dev_fop_poll,
+	.open		= lirc_rx51_open,
+	.release	= lirc_rx51_release,
+};
+
+static struct lirc_driver lirc_rx51_driver = {
+	.name		= DRIVER_NAME,
+	.minor		= -1,
+	.code_length	= 1,
+	.data		= &lirc_rx51,
+	.fops		= &lirc_fops,
+	.owner		= THIS_MODULE,
+};
+
+#ifdef CONFIG_PM
+
+static int lirc_rx51_suspend(struct platform_device *dev, pm_message_t state)
+{
+	/*
+	 * In case the device is still open, do not suspend. Normally
+	 * this should not be a problem as lircd only keeps the device
+	 * open only for short periods of time. We also don't want to
+	 * get involved with race conditions that might happen if we
+	 * were in a middle of a transmit. Thus, we defer any suspend
+	 * actions until transmit has completed.
+	 */
+	if (test_and_set_bit(1, &lirc_rx51.device_is_open))
+		return -EAGAIN;
+
+	clear_bit(1, &lirc_rx51.device_is_open);
+
+	return 0;
+}
+
+static int lirc_rx51_resume(struct platform_device *dev)
+{
+	return 0;
+}
+
+#else
+
+#define lirc_rx51_suspend	NULL
+#define lirc_rx51_resume	NULL
+
+#endif /* CONFIG_PM */
+
+static int __devinit lirc_rx51_probe(struct platform_device *dev)
+{
+	lirc_rx51_driver.features = LIRC_RX51_DRIVER_FEATURES;
+	lirc_rx51.pdata = dev->dev.platform_data;
+	lirc_rx51.pwm_timer_num = lirc_rx51.pdata->pwm_timer;
+	lirc_rx51.dev = &dev->dev;
+	lirc_rx51_driver.dev = &dev->dev;
+	lirc_rx51_driver.minor = lirc_register_driver(&lirc_rx51_driver);
+	init_waitqueue_head(&lirc_rx51.wqueue);
+
+	if (lirc_rx51_driver.minor < 0) {
+		dev_err(lirc_rx51.dev, ": lirc_register_driver failed: %d\n",
+		       lirc_rx51_driver.minor);
+		return lirc_rx51_driver.minor;
+	}
+	dev_info(lirc_rx51.dev, "registration ok, minor: %d, pwm: %d\n",
+		 lirc_rx51_driver.minor, lirc_rx51.pwm_timer_num);
+
+	return 0;
+}
+
+static int __exit lirc_rx51_remove(struct platform_device *dev)
+{
+	return lirc_unregister_driver(lirc_rx51_driver.minor);
+}
+
+struct platform_driver lirc_rx51_platform_driver = {
+	.probe		= lirc_rx51_probe,
+	.remove		= __exit_p(lirc_rx51_remove),
+	.suspend	= lirc_rx51_suspend,
+	.resume		= lirc_rx51_resume,
+	.remove		= __exit_p(lirc_rx51_remove),
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init lirc_rx51_init(void)
+{
+	return platform_driver_register(&lirc_rx51_platform_driver);
+}
+module_init(lirc_rx51_init);
+
+static void __exit lirc_rx51_exit(void)
+{
+	platform_driver_unregister(&lirc_rx51_platform_driver);
+}
+module_exit(lirc_rx51_exit);
+
+MODULE_DESCRIPTION("LIRC TX driver for Nokia RX51");
+MODULE_AUTHOR("Nokia Corporation");
+MODULE_LICENSE("GPL");