V4L/DVB (13100): cx23885: Add IR input keypress handling and enable for the HVR-1850

This changes adds IR Rx keypress input event handling to the CX23885 module.
This change specifically only adds input handling for IR devices implemented as
v4l2_subdevices, using only the pulse width mode (for now), and only with
RC-5 remotes.  The V4L-DVB infrastructure is missing too much to support RC-6
mode 6A as used in many media center remotes.   The grey Hauppauge RC-5 remote
and HVR-1850 IR receiver work now.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 418 insertions, 0 deletions

diff --git a/drivers/media/video/cx23885/cx23885-input.c b/drivers/media/video/cx23885/cx23885-input.c
new file mode 100644
index 000000000000..c208079f4e9d
--- /dev/null
+++ b/drivers/media/video/cx23885/cx23885-input.c
@@ -0,0 +1,418 @@
+/*
+ *  Driver for the Conexant CX23885/7/8 PCIe bridge
+ *
+ *  Infrared remote control input device
+ *
+ *  Most of this file is
+ *
+ *  Copyright (C) 2009  Andy Walls <awalls@radix.net>
+ *
+ *  However, the cx23885_input_{init,fini} functions contained herein are
+ *  derived from Linux kernel files linux/media/video/.../...-input.c marked as:
+ *
+ *  Copyright (C) 2008 <srinivasa.deevi at conexant dot com>
+ *  Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
+ *		       Markus Rechberger <mrechberger@gmail.com>
+ *		       Mauro Carvalho Chehab <mchehab@infradead.org>
+ *		       Sascha Sommer <saschasommer@freenet.de>
+ *  Copyright (C) 2004, 2005 Chris Pascoe
+ *  Copyright (C) 2003, 2004 Gerd Knorr
+ *  Copyright (C) 2003 Pavel Machek
+ *
+ *  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., 51 Franklin Street, Fifth Floor, Boston, MA
+ *  02110-1301, USA.
+ */
+
+#include <linux/input.h>
+#include <media/ir-common.h>
+#include <media/v4l2-subdev.h>
+
+#include "cx23885.h"
+
+#define RC5_BITS		14
+#define RC5_HALF_BITS		(2*RC5_BITS)
+#define RC5_HALF_BITS_MASK	((1 << RC5_HALF_BITS) - 1)
+
+#define RC5_START_BITS_NORMAL	0x3 /* Command range  0 -  63 */
+#define RC5_START_BITS_EXTENDED	0x2 /* Command range 64 - 127 */
+
+#define RC5_EXTENDED_COMMAND_OFFSET	64
+
+static inline unsigned int rc5_command(u32 rc5_baseband)
+{
+	return RC5_INSTR(rc5_baseband) +
+		((RC5_START(rc5_baseband) == RC5_START_BITS_EXTENDED)
+			? RC5_EXTENDED_COMMAND_OFFSET : 0);
+}
+
+static void cx23885_input_process_raw_rc5(struct cx23885_dev *dev)
+{
+	struct card_ir *ir_input = dev->ir_input;
+	unsigned int code, command;
+	u32 rc5;
+
+	/* Ignore codes that are too short to be valid RC-5 */
+	if (ir_input->last_bit < (RC5_HALF_BITS - 1))
+		return;
+
+	/* The library has the manchester coding backwards; XOR to adapt. */
+	code = (ir_input->code & RC5_HALF_BITS_MASK) ^ RC5_HALF_BITS_MASK;
+	rc5 = ir_rc5_decode(code);
+
+	switch (RC5_START(rc5)) {
+	case RC5_START_BITS_NORMAL:
+		break;
+	case RC5_START_BITS_EXTENDED:
+		/* Don't allow if the remote only emits standard commands */
+		if (ir_input->start == RC5_START_BITS_NORMAL)
+			return;
+		break;
+	default:
+		return;
+	}
+
+	if (ir_input->addr != RC5_ADDR(rc5))
+		return;
+
+	/* Don't generate a keypress for RC-5 auto-repeated keypresses */
+	command = rc5_command(rc5);
+	if (RC5_TOGGLE(rc5) != RC5_TOGGLE(ir_input->last_rc5) ||
+	    command != rc5_command(ir_input->last_rc5) ||
+	    /* Catch T == 0, CMD == 0 (e.g. '0') as first keypress after init */
+	    RC5_START(ir_input->last_rc5) == 0) {
+		/* This keypress is differnet: not an auto repeat */
+		ir_input_nokey(ir_input->dev, &ir_input->ir);
+		ir_input_keydown(ir_input->dev, &ir_input->ir,
+				 command, ir_input->code);
+	}
+	ir_input->last_rc5 = rc5;
+
+	/* Schedule when we should do the key up event: ir_input_nokey() */
+	mod_timer(&ir_input->timer_keyup,
+		  jiffies + msecs_to_jiffies(ir_input->rc5_key_timeout));
+}
+
+static void cx23885_input_next_pulse_width_rc5(struct cx23885_dev *dev,
+					       u32 ns_pulse)
+{
+	const int rc5_quarterbit_ns = 444444; /* 32 cycles/36 kHz/2 = 444 us */
+	struct card_ir *ir_input = dev->ir_input;
+	int i, level, quarterbits, halfbits;
+
+	if (!ir_input->active) {
+		ir_input->active = 1;
+		/* assume an initial space that we may not detect or measure */
+		ir_input->code = 0;
+		ir_input->last_bit = 0;
+	}
+
+	if (ns_pulse == V4L2_SUBDEV_IR_PULSE_RX_SEQ_END) {
+		ir_input->last_bit++; /* Account for the final space */
+		ir_input->active = 0;
+		cx23885_input_process_raw_rc5(dev);
+		return;
+	}
+
+	level = (ns_pulse & V4L2_SUBDEV_IR_PULSE_LEVEL_MASK) ? 1 : 0;
+
+	/* Skip any leading space to sync to the start bit */
+	if (ir_input->last_bit == 0 && level == 0)
+		return;
+
+	/*
+	 * With valid RC-5 we can get up to two consecutive half-bits in a
+	 * single pulse measurment.  Experiments have shown that the duration
+	 * of a half-bit can vary.  Make sure we always end up with an even
+	 * number of quarter bits at the same level (mark or space).
+	 */
+	ns_pulse &= V4L2_SUBDEV_IR_PULSE_MAX_WIDTH_NS;
+	quarterbits = ns_pulse / rc5_quarterbit_ns;
+	if (quarterbits & 1)
+		quarterbits++;
+	halfbits = quarterbits / 2;
+
+	for (i = 0; i < halfbits; i++) {
+		ir_input->last_bit++;
+		ir_input->code |= (level << ir_input->last_bit);
+
+		if (ir_input->last_bit >= RC5_HALF_BITS-1) {
+			ir_input->active = 0;
+			cx23885_input_process_raw_rc5(dev);
+			/*
+			 * If level is 1, a leading mark is invalid for RC5.
+			 * If level is 0, we scan past extra intial space.
+			 * Either way we don't want to reactivate collecting
+			 * marks or spaces here with any left over half-bits.
+			 */
+			break;
+		}
+	}
+}
+
+static void cx23885_input_process_pulse_widths_rc5(struct cx23885_dev *dev,
+						   bool add_eom)
+{
+	struct card_ir *ir_input = dev->ir_input;
+	struct ir_input_state *ir_input_state = &ir_input->ir;
+
+	u32 ns_pulse[RC5_HALF_BITS+1];
+	ssize_t num = 0;
+	int count, i;
+
+	do {
+		v4l2_subdev_call(dev->sd_ir, ir, rx_read, (u8 *) ns_pulse,
+				 sizeof(ns_pulse), &num);
+
+		count = num / sizeof(u32);
+
+		/* Append an end of Rx seq, if the caller requested */
+		if (add_eom && count < ARRAY_SIZE(ns_pulse)) {
+			ns_pulse[count] = V4L2_SUBDEV_IR_PULSE_RX_SEQ_END;
+			count++;
+		}
+
+		/* Just drain the Rx FIFO, if we're called, but not RC-5 */
+		if (ir_input_state->ir_type != IR_TYPE_RC5)
+			continue;
+
+		for (i = 0; i < count; i++)
+			cx23885_input_next_pulse_width_rc5(dev, ns_pulse[i]);
+	} while (num != 0);
+}
+
+void cx23885_input_rx_work_handler(struct cx23885_dev *dev, u32 events)
+{
+	struct v4l2_subdev_ir_parameters params;
+	int overrun, data_available;
+
+	if (dev->sd_ir == NULL || events == 0)
+		return;
+
+	switch (dev->board) {
+	case CX23885_BOARD_HAUPPAUGE_HVR1850:
+		/*
+		 * The only board we handle right now.  However other boards
+		 * using the CX2388x integrated IR controller should be similar
+		 */
+		break;
+	default:
+		return;
+	}
+
+	overrun = events & (V4L2_SUBDEV_IR_RX_SW_FIFO_OVERRUN |
+			    V4L2_SUBDEV_IR_RX_HW_FIFO_OVERRUN);
+
+	data_available = events & (V4L2_SUBDEV_IR_RX_END_OF_RX_DETECTED |
+				   V4L2_SUBDEV_IR_RX_FIFO_SERVICE_REQ);
+
+	if (overrun) {
+		/* If there was a FIFO overrun, stop the device */
+		v4l2_subdev_call(dev->sd_ir, ir, rx_g_parameters, &params);
+		params.enable = false;
+		/* Mitigate race with cx23885_input_ir_stop() */
+		params.shutdown = atomic_read(&dev->ir_input_stopping);
+		v4l2_subdev_call(dev->sd_ir, ir, rx_s_parameters, &params);
+	}
+
+	if (data_available)
+		cx23885_input_process_pulse_widths_rc5(dev, overrun);
+
+	if (overrun) {
+		/* If there was a FIFO overrun, clear & restart the device */
+		params.enable = true;
+		/* Mitigate race with cx23885_input_ir_stop() */
+		params.shutdown = atomic_read(&dev->ir_input_stopping);
+		v4l2_subdev_call(dev->sd_ir, ir, rx_s_parameters, &params);
+	}
+}
+
+static void cx23885_input_ir_start(struct cx23885_dev *dev)
+{
+	struct card_ir *ir_input = dev->ir_input;
+	struct ir_input_state *ir_input_state = &ir_input->ir;
+	struct v4l2_subdev_ir_parameters params;
+
+	if (dev->sd_ir == NULL)
+		return;
+
+	atomic_set(&dev->ir_input_stopping, 0);
+
+	/* keyup timer set up, if needed */
+	switch (dev->board) {
+	case CX23885_BOARD_HAUPPAUGE_HVR1850:
+		setup_timer(&ir_input->timer_keyup,
+			    ir_rc5_timer_keyup,	/* Not actually RC-5 specific */
+			    (unsigned long) ir_input);
+		if (ir_input_state->ir_type == IR_TYPE_RC5) {
+			/*
+			 * RC-5 repeats a held key every
+			 * 64 bits * (2 * 32/36000) sec/bit = 113.778 ms
+			 */
+			ir_input->rc5_key_timeout = 115;
+		}
+		break;
+	}
+
+	v4l2_subdev_call(dev->sd_ir, ir, rx_g_parameters, &params);
+	switch (dev->board) {
+	case CX23885_BOARD_HAUPPAUGE_HVR1850:
+		/*
+		 * The IR controller on this board only returns pulse widths.
+		 * Any other mode setting will fail to set up the device.
+		*/
+		params.mode = V4L2_SUBDEV_IR_MODE_PULSE_WIDTH;
+		params.enable = true;
+		params.interrupt_enable = true;
+		params.shutdown = false;
+
+		/* Setup for baseband compatible with both RC-5 and RC-6A */
+		params.modulation = false;
+		/* RC-5:  2,222,222 ns = 1/36 kHz * 32 cycles * 2 marks * 1.25*/
+		/* RC-6A: 3,333,333 ns = 1/36 kHz * 16 cycles * 6 marks * 1.25*/
+		params.max_pulse_width = 3333333; /* ns */
+		/* RC-5:    666,667 ns = 1/36 kHz * 32 cycles * 1 mark * 0.75 */
+		/* RC-6A:   333,333 ns = 1/36 kHz * 16 cycles * 1 mark * 0.75 */
+		params.noise_filter_min_width = 333333; /* ns */
+		/*
+		 * This board has inverted receive sense:
+		 * mark is received as low logic level;
+		 * falling edges are detected as rising edges; etc.
+		 */
+		params.invert = true;
+		break;
+	}
+	v4l2_subdev_call(dev->sd_ir, ir, rx_s_parameters, &params);
+}
+
+static void cx23885_input_ir_stop(struct cx23885_dev *dev)
+{
+	struct card_ir *ir_input = dev->ir_input;
+	struct v4l2_subdev_ir_parameters params;
+
+	if (dev->sd_ir == NULL)
+		return;
+
+	/*
+	 * Stop the sd_ir subdevice from generating notifications and
+	 * scheduling work.
+	 * It is shutdown this way in order to mitigate a race with
+	 * cx23885_input_rx_work_handler() in the overrun case, which could
+	 * re-enable the subdevice.
+	 */
+	atomic_set(&dev->ir_input_stopping, 1);
+	v4l2_subdev_call(dev->sd_ir, ir, rx_g_parameters, &params);
+	while (params.shutdown == false) {
+		params.enable = false;
+		params.interrupt_enable = false;
+		params.shutdown = true;
+		v4l2_subdev_call(dev->sd_ir, ir, rx_s_parameters, &params);
+		v4l2_subdev_call(dev->sd_ir, ir, rx_g_parameters, &params);
+	}
+
+	flush_scheduled_work();
+
+	switch (dev->board) {
+	case CX23885_BOARD_HAUPPAUGE_HVR1850:
+		del_timer_sync(&ir_input->timer_keyup);
+		break;
+	}
+}
+
+int cx23885_input_init(struct cx23885_dev *dev)
+{
+	struct card_ir *ir;
+	struct input_dev *input_dev;
+	struct ir_scancode_table *ir_codes = NULL;
+	int ir_type, ir_addr, ir_start;
+	int ret;
+
+	/*
+	 * If the IR device (hardware registers, chip, GPIO lines, etc.) isn't
+	 * encapsulated in a v4l2_subdev, then I'm not going to deal with it.
+	 */
+	if (dev->sd_ir == NULL)
+		return -ENODEV;
+
+	switch (dev->board) {
+	case CX23885_BOARD_HAUPPAUGE_HVR1850:
+		/* Parameters for the grey Hauppauge remote for the HVR-1850 */
+		ir_codes = &ir_codes_hauppauge_new_table;
+		ir_type = IR_TYPE_RC5;
+		ir_addr = 0x1e; /* RC-5 system bits emitted by the remote */
+		ir_start = RC5_START_BITS_NORMAL; /* A basic RC-5 remote */
+		break;
+	}
+	if (ir_codes == NULL)
+		return -ENODEV;
+
+	ir = kzalloc(sizeof(*ir), GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (!ir || !input_dev) {
+		ret = -ENOMEM;
+		goto err_out_free;
+	}
+
+	ir->dev = input_dev;
+	ir->addr = ir_addr;
+	ir->start = ir_start;
+
+	/* init input device */
+	snprintf(ir->name, sizeof(ir->name), "cx23885 IR (%s)",
+		 cx23885_boards[dev->board].name);
+	snprintf(ir->phys, sizeof(ir->phys), "pci-%s/ir0", pci_name(dev->pci));
+
+	ir_input_init(input_dev, &ir->ir, ir_type, ir_codes);
+	input_dev->name = ir->name;
+	input_dev->phys = ir->phys;
+	input_dev->id.bustype = BUS_PCI;
+	input_dev->id.version = 1;
+	if (dev->pci->subsystem_vendor) {
+		input_dev->id.vendor  = dev->pci->subsystem_vendor;
+		input_dev->id.product = dev->pci->subsystem_device;
+	} else {
+		input_dev->id.vendor  = dev->pci->vendor;
+		input_dev->id.product = dev->pci->device;
+	}
+	input_dev->dev.parent = &dev->pci->dev;
+
+	dev->ir_input = ir;
+	cx23885_input_ir_start(dev);
+
+	ret = input_register_device(ir->dev);
+	if (ret)
+		goto err_out_stop;
+
+	return 0;
+
+err_out_stop:
+	cx23885_input_ir_stop(dev);
+	dev->ir_input = NULL;
+err_out_free:
+	input_free_device(input_dev);
+	kfree(ir);
+	return ret;
+}
+
+void cx23885_input_fini(struct cx23885_dev *dev)
+{
+	/* Always stop the IR hardware from generating interrupts */
+	cx23885_input_ir_stop(dev);
+
+	if (dev->ir_input == NULL)
+		return;
+	input_unregister_device(dev->ir_input->dev);
+	kfree(dev->ir_input);
+	dev->ir_input = NULL;
+}