Message-ID: <20100726233025.GH21225@redhat.com>
Date:	Mon, 26 Jul 2010 19:30:25 -0400
From:	Jarod Wilson <jarod@...hat.com>
To:	linux-kernel@...r.kernel.org
Cc:	linux-media@...r.kernel.org, linux-input@...r.kernel.org
Subject: [PATCH 07/15] staging/lirc: add lirc_ite8709 driver

Signed-off-by: Jarod Wilson <jarod@...hat.com>
---
 drivers/staging/lirc/lirc_ite8709.c |  542 +++++++++++++++++++++++++++++++++++
 1 files changed, 542 insertions(+), 0 deletions(-)
 create mode 100644 drivers/staging/lirc/lirc_ite8709.c

diff --git a/drivers/staging/lirc/lirc_ite8709.c b/drivers/staging/lirc/lirc_ite8709.c
new file mode 100644
index 0000000..9352f45
--- /dev/null
+++ b/drivers/staging/lirc/lirc_ite8709.c
@@ -0,0 +1,542 @@
+/*
+ * LIRC driver for ITE8709 CIR port
+ *
+ * Copyright (C) 2008 Grégory Lardière <spmf2004-lirc@...oo.fr>
+ *
+ * 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/sched.h>
+#include <linux/delay.h>
+#include <linux/pnp.h>
+#include <linux/io.h>
+
+#include <media/lirc.h>
+#include <media/lirc_dev.h>
+
+#define LIRC_DRIVER_NAME "lirc_ite8709"
+
+#define BUF_CHUNK_SIZE	sizeof(int)
+#define BUF_SIZE	(128*BUF_CHUNK_SIZE)
+
+/*
+ * The ITE8709 device seems to be the combination of IT8512 superIO chip and
+ * a specific firmware running on the IT8512's embedded micro-controller.
+ * In addition of the embedded micro-controller, the IT8512 chip contains a
+ * CIR module and several other modules. A few modules are directly accessible
+ * by the host CPU, but most of them are only accessible by the
+ * micro-controller. The CIR module is only accessible by the micro-controller.
+ * The battery-backed SRAM module is accessible by the host CPU and the
+ * micro-controller. So one of the MC's firmware role is to act as a bridge
+ * between the host CPU and the CIR module. The firmware implements a kind of
+ * communication protocol using the SRAM module as a shared memory. The IT8512
+ * specification is publicly available on ITE's web site, but the communication
+ * protocol is not, so it was reverse-engineered.
+ */
+
+/* ITE8709 Registers addresses and values (reverse-engineered) */
+#define ITE8709_MODE		0x1a
+#define ITE8709_REG_ADR		0x1b
+#define ITE8709_REG_VAL		0x1c
+#define ITE8709_IIR		0x1e  /* Interrupt identification register */
+#define ITE8709_RFSR		0x1f  /* Receiver FIFO status register */
+#define ITE8709_FIFO_START	0x20
+
+#define ITE8709_MODE_READY	0X00
+#define ITE8709_MODE_WRITE	0X01
+#define ITE8709_MODE_READ	0X02
+#define ITE8709_IIR_RDAI	0x02  /* Receiver data available interrupt */
+#define ITE8709_IIR_RFOI	0x04  /* Receiver FIFO overrun interrupt */
+#define ITE8709_RFSR_MASK	0x3f  /* FIFO byte count mask */
+
+/*
+ * IT8512 CIR-module registers addresses and values
+ * (from IT8512 E/F specification v0.4.1)
+ */
+#define IT8512_REG_MSTCR	0x01  /* Master control register */
+#define IT8512_REG_IER		0x02  /* Interrupt enable register */
+#define IT8512_REG_CFR		0x04  /* Carrier frequency register */
+#define IT8512_REG_RCR		0x05  /* Receive control register */
+#define IT8512_REG_BDLR		0x08  /* Baud rate divisor low byte register */
+#define IT8512_REG_BDHR		0x09  /* Baud rate divisor high byte register */
+
+#define IT8512_MSTCR_RESET	0x01  /* Reset registers to default value */
+#define IT8512_MSTCR_FIFOCLR	0x02  /* Clear FIFO */
+#define IT8512_MSTCR_FIFOTL_7	0x04  /* FIFO threshold level : 7 */
+#define IT8512_MSTCR_FIFOTL_25	0x0c  /* FIFO threshold level : 25 */
+#define IT8512_IER_RDAIE	0x02  /* Enable data interrupt request */
+#define IT8512_IER_RFOIE	0x04  /* Enable FIFO overrun interrupt req */
+#define IT8512_IER_IEC		0x80  /* Enable interrupt request */
+#define IT8512_CFR_CF_36KHZ	0x09  /* Carrier freq : low speed, 36kHz */
+#define IT8512_RCR_RXDCR_1	0x01  /* Demodulation carrier range : 1 */
+#define IT8512_RCR_RXACT	0x08  /* Receiver active */
+#define IT8512_RCR_RXEN		0x80  /* Receiver enable */
+#define IT8512_BDR_6		6     /* Baud rate divisor : 6 */
+
+/* Actual values used by this driver */
+#define CFG_FIFOTL	IT8512_MSTCR_FIFOTL_25
+#define CFG_CR_FREQ	IT8512_CFR_CF_36KHZ
+#define CFG_DCR		IT8512_RCR_RXDCR_1
+#define CFG_BDR		IT8512_BDR_6
+#define CFG_TIMEOUT	100000 /* Rearm interrupt when a space is > 100 ms */
+
+static int debug;
+
+struct ite8709_device {
+	int use_count;
+	int io;
+	int irq;
+	spinlock_t hardware_lock;
+	unsigned long long acc_pulse;
+	unsigned long long acc_space;
+	char lastbit;
+	struct timeval last_tv;
+	struct lirc_driver driver;
+	struct tasklet_struct tasklet;
+	char force_rearm;
+	char rearmed;
+	char device_busy;
+};
+
+#define dprintk(fmt, args...)					\
+	do {							\
+		if (debug)					\
+			printk(KERN_DEBUG LIRC_DRIVER_NAME ": "	\
+				fmt, ## args);			\
+	} while (0)
+
+
+static unsigned char ite8709_read(struct ite8709_device *dev,
+					unsigned char port)
+{
+	outb(port, dev->io);
+	return inb(dev->io+1);
+}
+
+static void ite8709_write(struct ite8709_device *dev, unsigned char port,
+				unsigned char data)
+{
+	outb(port, dev->io);
+	outb(data, dev->io+1);
+}
+
+static void ite8709_wait_device(struct ite8709_device *dev)
+{
+	int i = 0;
+	/*
+	 * loop until device tells it's ready to continue
+	 * iterations count is usually ~750 but can sometimes achieve 13000
+	 */
+	for (i = 0; i < 15000; i++) {
+		udelay(2);
+		if (ite8709_read(dev, ITE8709_MODE) == ITE8709_MODE_READY)
+			break;
+	}
+}
+
+static void ite8709_write_register(struct ite8709_device *dev,
+				unsigned char reg_adr, unsigned char reg_value)
+{
+	ite8709_wait_device(dev);
+
+	ite8709_write(dev, ITE8709_REG_VAL, reg_value);
+	ite8709_write(dev, ITE8709_REG_ADR, reg_adr);
+	ite8709_write(dev, ITE8709_MODE, ITE8709_MODE_WRITE);
+}
+
+static void ite8709_init_hardware(struct ite8709_device *dev)
+{
+	spin_lock_irq(&dev->hardware_lock);
+	dev->device_busy = 1;
+	spin_unlock_irq(&dev->hardware_lock);
+
+	ite8709_write_register(dev, IT8512_REG_BDHR, (CFG_BDR >> 8) & 0xff);
+	ite8709_write_register(dev, IT8512_REG_BDLR, CFG_BDR & 0xff);
+	ite8709_write_register(dev, IT8512_REG_CFR, CFG_CR_FREQ);
+	ite8709_write_register(dev, IT8512_REG_IER,
+			IT8512_IER_IEC | IT8512_IER_RFOIE | IT8512_IER_RDAIE);
+	ite8709_write_register(dev, IT8512_REG_RCR, CFG_DCR);
+	ite8709_write_register(dev, IT8512_REG_MSTCR,
+					CFG_FIFOTL | IT8512_MSTCR_FIFOCLR);
+	ite8709_write_register(dev, IT8512_REG_RCR,
+				IT8512_RCR_RXEN | IT8512_RCR_RXACT | CFG_DCR);
+
+	spin_lock_irq(&dev->hardware_lock);
+	dev->device_busy = 0;
+	spin_unlock_irq(&dev->hardware_lock);
+
+	tasklet_enable(&dev->tasklet);
+}
+
+static void ite8709_drop_hardware(struct ite8709_device *dev)
+{
+	tasklet_disable(&dev->tasklet);
+
+	spin_lock_irq(&dev->hardware_lock);
+	dev->device_busy = 1;
+	spin_unlock_irq(&dev->hardware_lock);
+
+	ite8709_write_register(dev, IT8512_REG_RCR, 0);
+	ite8709_write_register(dev, IT8512_REG_MSTCR,
+				IT8512_MSTCR_RESET | IT8512_MSTCR_FIFOCLR);
+
+	spin_lock_irq(&dev->hardware_lock);
+	dev->device_busy = 0;
+	spin_unlock_irq(&dev->hardware_lock);
+}
+
+static int ite8709_set_use_inc(void *data)
+{
+	struct ite8709_device *dev;
+	dev = data;
+	if (dev->use_count == 0)
+		ite8709_init_hardware(dev);
+	dev->use_count++;
+	return 0;
+}
+
+static void ite8709_set_use_dec(void *data)
+{
+	struct ite8709_device *dev;
+	dev = data;
+	dev->use_count--;
+	if (dev->use_count == 0)
+		ite8709_drop_hardware(dev);
+}
+
+static void ite8709_add_read_queue(struct ite8709_device *dev, int flag,
+					unsigned long long val)
+{
+	int value;
+
+	dprintk("add a %llu usec %s\n", val, flag ? "pulse" : "space");
+
+	value = (val > PULSE_MASK) ? PULSE_MASK : val;
+	if (flag)
+		value |= PULSE_BIT;
+
+	if (!lirc_buffer_full(dev->driver.rbuf)) {
+		lirc_buffer_write(dev->driver.rbuf, (void *) &value);
+		wake_up(&dev->driver.rbuf->wait_poll);
+	}
+}
+
+static irqreturn_t ite8709_interrupt(int irq, void *dev_id)
+{
+	unsigned char data;
+	int iir, rfsr, i;
+	int fifo = 0;
+	char bit;
+	struct timeval curr_tv;
+
+	/* Bit duration in microseconds */
+	const unsigned long bit_duration = 1000000ul / (115200 / CFG_BDR);
+
+	struct ite8709_device *dev;
+	dev = dev_id;
+
+	/*
+	 * If device is busy, we simply discard data because we are in one of
+	 * these two cases : shutting down or rearming the device, so this
+	 * doesn't really matter and this avoids waiting too long in IRQ ctx
+	 */
+	spin_lock(&dev->hardware_lock);
+	if (dev->device_busy) {
+		spin_unlock(&dev->hardware_lock);
+		return IRQ_RETVAL(IRQ_HANDLED);
+	}
+
+	iir = ite8709_read(dev, ITE8709_IIR);
+
+	switch (iir) {
+	case ITE8709_IIR_RFOI:
+		dprintk("fifo overrun, scheduling forced rearm just in case\n");
+		dev->force_rearm = 1;
+		tasklet_schedule(&dev->tasklet);
+		spin_unlock(&dev->hardware_lock);
+		return IRQ_RETVAL(IRQ_HANDLED);
+
+	case ITE8709_IIR_RDAI:
+		rfsr = ite8709_read(dev, ITE8709_RFSR);
+		fifo = rfsr & ITE8709_RFSR_MASK;
+		if (fifo > 32)
+			fifo = 32;
+		dprintk("iir: 0x%x rfsr: 0x%x fifo: %d\n", iir, rfsr, fifo);
+
+		if (dev->rearmed) {
+			do_gettimeofday(&curr_tv);
+			dev->acc_space += 1000000ull
+				* (curr_tv.tv_sec - dev->last_tv.tv_sec)
+				+ (curr_tv.tv_usec - dev->last_tv.tv_usec);
+			dev->rearmed = 0;
+		}
+		for (i = 0; i < fifo; i++) {
+			data = ite8709_read(dev, i+ITE8709_FIFO_START);
+			data = ~data;
+			/* Loop through */
+			for (bit = 0; bit < 8; ++bit) {
+				if ((data >> bit) & 1) {
+					dev->acc_pulse += bit_duration;
+					if (dev->lastbit == 0) {
+						ite8709_add_read_queue(dev, 0,
+							dev->acc_space);
+						dev->acc_space = 0;
+					}
+				} else {
+					dev->acc_space += bit_duration;
+					if (dev->lastbit == 1) {
+						ite8709_add_read_queue(dev, 1,
+							dev->acc_pulse);
+						dev->acc_pulse = 0;
+					}
+				}
+				dev->lastbit = (data >> bit) & 1;
+			}
+		}
+		ite8709_write(dev, ITE8709_RFSR, 0);
+
+		if (dev->acc_space > CFG_TIMEOUT) {
+			dprintk("scheduling rearm IRQ\n");
+			do_gettimeofday(&dev->last_tv);
+			dev->force_rearm = 0;
+			tasklet_schedule(&dev->tasklet);
+		}
+
+		spin_unlock(&dev->hardware_lock);
+		return IRQ_RETVAL(IRQ_HANDLED);
+
+	default:
+		/* not our irq */
+		dprintk("unknown IRQ (shouldn't happen) !!\n");
+		spin_unlock(&dev->hardware_lock);
+		return IRQ_RETVAL(IRQ_NONE);
+	}
+}
+
+static void ite8709_rearm_irq(unsigned long data)
+{
+	struct ite8709_device *dev;
+	unsigned long flags;
+	dev = (struct ite8709_device *) data;
+
+	spin_lock_irqsave(&dev->hardware_lock, flags);
+	dev->device_busy = 1;
+	spin_unlock_irqrestore(&dev->hardware_lock, flags);
+
+	if (dev->force_rearm || dev->acc_space > CFG_TIMEOUT) {
+		dprintk("rearming IRQ\n");
+		ite8709_write_register(dev, IT8512_REG_RCR,
+						IT8512_RCR_RXACT | CFG_DCR);
+		ite8709_write_register(dev, IT8512_REG_MSTCR,
+					CFG_FIFOTL | IT8512_MSTCR_FIFOCLR);
+		ite8709_write_register(dev, IT8512_REG_RCR,
+				IT8512_RCR_RXEN | IT8512_RCR_RXACT | CFG_DCR);
+		if (!dev->force_rearm)
+			dev->rearmed = 1;
+		dev->force_rearm = 0;
+	}
+
+	spin_lock_irqsave(&dev->hardware_lock, flags);
+	dev->device_busy = 0;
+	spin_unlock_irqrestore(&dev->hardware_lock, flags);
+}
+
+static int ite8709_cleanup(struct ite8709_device *dev, int stage, int errno,
+				char *msg)
+{
+	if (msg != NULL)
+		printk(KERN_ERR LIRC_DRIVER_NAME ": %s\n", msg);
+
+	switch (stage) {
+	case 6:
+		if (dev->use_count > 0)
+			ite8709_drop_hardware(dev);
+	case 5:
+		free_irq(dev->irq, dev);
+	case 4:
+		release_region(dev->io, 2);
+	case 3:
+		lirc_unregister_driver(dev->driver.minor);
+	case 2:
+		lirc_buffer_free(dev->driver.rbuf);
+		kfree(dev->driver.rbuf);
+	case 1:
+		kfree(dev);
+	case 0:
+		;
+	}
+
+	return errno;
+}
+
+static int __devinit ite8709_pnp_probe(struct pnp_dev *dev,
+					const struct pnp_device_id *dev_id)
+{
+	struct lirc_driver *driver;
+	struct ite8709_device *ite8709_dev;
+	int ret;
+
+	/* Check resources validity */
+	if (!pnp_irq_valid(dev, 0))
+		return ite8709_cleanup(NULL, 0, -ENODEV, "invalid IRQ");
+	if (!pnp_port_valid(dev, 2))
+		return ite8709_cleanup(NULL, 0, -ENODEV, "invalid IO port");
+
+	/* Allocate memory for device struct */
+	ite8709_dev = kzalloc(sizeof(struct ite8709_device), GFP_KERNEL);
+	if (ite8709_dev == NULL)
+		return ite8709_cleanup(NULL, 0, -ENOMEM, "kzalloc failed");
+	pnp_set_drvdata(dev, ite8709_dev);
+
+	/* Initialize device struct */
+	ite8709_dev->use_count = 0;
+	ite8709_dev->irq = pnp_irq(dev, 0);
+	ite8709_dev->io = pnp_port_start(dev, 2);
+	ite8709_dev->hardware_lock =
+		__SPIN_LOCK_UNLOCKED(ite8709_dev->hardware_lock);
+	ite8709_dev->acc_pulse = 0;
+	ite8709_dev->acc_space = 0;
+	ite8709_dev->lastbit = 0;
+	do_gettimeofday(&ite8709_dev->last_tv);
+	tasklet_init(&ite8709_dev->tasklet, ite8709_rearm_irq,
+							(long) ite8709_dev);
+	ite8709_dev->force_rearm = 0;
+	ite8709_dev->rearmed = 0;
+	ite8709_dev->device_busy = 0;
+
+	/* Initialize driver struct */
+	driver = &ite8709_dev->driver;
+	strcpy(driver->name, LIRC_DRIVER_NAME);
+	driver->minor = -1;
+	driver->code_length = sizeof(int) * 8;
+	driver->sample_rate = 0;
+	driver->features = LIRC_CAN_REC_MODE2;
+	driver->data = ite8709_dev;
+	driver->add_to_buf = NULL;
+	driver->set_use_inc = ite8709_set_use_inc;
+	driver->set_use_dec = ite8709_set_use_dec;
+	driver->dev = &dev->dev;
+	driver->owner = THIS_MODULE;
+
+	/* Initialize LIRC buffer */
+	driver->rbuf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
+	if (!driver->rbuf)
+		return ite8709_cleanup(ite8709_dev, 1, -ENOMEM,
+				       "can't allocate lirc_buffer");
+	if (lirc_buffer_init(driver->rbuf, BUF_CHUNK_SIZE, BUF_SIZE))
+		return ite8709_cleanup(ite8709_dev, 1, -ENOMEM,
+				       "lirc_buffer_init() failed");
+
+	/* Register LIRC driver */
+	ret = lirc_register_driver(driver);
+	if (ret < 0)
+		return ite8709_cleanup(ite8709_dev, 2, ret,
+					"lirc_register_driver() failed");
+
+	/* Reserve I/O port access */
+	if (!request_region(ite8709_dev->io, 2, LIRC_DRIVER_NAME))
+		return ite8709_cleanup(ite8709_dev, 3, -EBUSY,
+						"i/o port already in use");
+
+	/* Reserve IRQ line */
+	ret = request_irq(ite8709_dev->irq, ite8709_interrupt, 0,
+					LIRC_DRIVER_NAME, ite8709_dev);
+	if (ret < 0)
+		return ite8709_cleanup(ite8709_dev, 4, ret,
+						"IRQ already in use");
+
+	/* Initialize hardware */
+	ite8709_drop_hardware(ite8709_dev); /* Shutdown hw until first use */
+
+	printk(KERN_INFO LIRC_DRIVER_NAME ": device found : irq=%d io=0x%x\n",
+					ite8709_dev->irq, ite8709_dev->io);
+
+	return 0;
+}
+
+static void __devexit ite8709_pnp_remove(struct pnp_dev *dev)
+{
+	struct ite8709_device *ite8709_dev;
+	ite8709_dev = pnp_get_drvdata(dev);
+
+	ite8709_cleanup(ite8709_dev, 6, 0, NULL);
+
+	printk(KERN_INFO LIRC_DRIVER_NAME ": device removed\n");
+}
+
+#ifdef CONFIG_PM
+static int ite8709_pnp_suspend(struct pnp_dev *dev, pm_message_t state)
+{
+	struct ite8709_device *ite8709_dev;
+	ite8709_dev = pnp_get_drvdata(dev);
+
+	if (ite8709_dev->use_count > 0)
+		ite8709_drop_hardware(ite8709_dev);
+
+	return 0;
+}
+
+static int ite8709_pnp_resume(struct pnp_dev *dev)
+{
+	struct ite8709_device *ite8709_dev;
+	ite8709_dev = pnp_get_drvdata(dev);
+
+	if (ite8709_dev->use_count > 0)
+		ite8709_init_hardware(ite8709_dev);
+
+	return 0;
+}
+#else
+#define ite8709_pnp_suspend NULL
+#define ite8709_pnp_resume NULL
+#endif
+
+static const struct pnp_device_id pnp_dev_table[] = {
+	{"ITE8709", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(pnp, pnp_dev_table);
+
+static struct pnp_driver ite8709_pnp_driver = {
+	.name           = LIRC_DRIVER_NAME,
+	.probe          = ite8709_pnp_probe,
+	.remove         = __devexit_p(ite8709_pnp_remove),
+	.suspend        = ite8709_pnp_suspend,
+	.resume         = ite8709_pnp_resume,
+	.id_table       = pnp_dev_table,
+};
+
+static int __init ite8709_init_module(void)
+{
+	return pnp_register_driver(&ite8709_pnp_driver);
+}
+module_init(ite8709_init_module);
+
+static void __exit ite8709_cleanup_module(void)
+{
+	pnp_unregister_driver(&ite8709_pnp_driver);
+}
+module_exit(ite8709_cleanup_module);
+
+MODULE_DESCRIPTION("LIRC driver for ITE8709 CIR port");
+MODULE_AUTHOR("Grégory Lardière");
+MODULE_LICENSE("GPL");
+
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Enable debugging messages");
-- 
1.7.1.1

-- 
Jarod Wilson
jarod@...hat.com

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